Nitrogen balance in a hilly semi-agricultural watershed in Northern Italy

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Linda Pieri

2011-03-01

Full Text Available The research was carried out for 7 years, 1998-2005, in a semi-agricultural watershed, called Centonara, set within a natural regional park and situated in the hills surrounding Bologna, northern Italy. This area is characterized by one of the most interesting badlands complexes in Europe and represents one of the main points of naturalistic interest. The watershed is partially cultivated (about 30% of the total area with arable crops, mostly cereals and alfalfa. To evaluate the impact of agricultural activity on the eco-sustainability of this area, the nitrogen (N balance was computed. Although it is only an estimation of the potential environmental damage, the nitrogen balance is a useful indicator of the risk posed to the environment from excessive nitrogen and can be useful to understand the possible effects of a certain type of agricultural and environmental management and policy. The balance was calculated by computing the difference between all inputs and all outputs. The nitrogen balance of the watershed was found to be sustainable, with an annual nitrogen balance ranging between –2.3 and +4.4 kg ha–1. Despite the limited presence of arable lands, the agricultural management played the main role in determining the sustainability of the watershed, strongly influencing both the principal N sources and sinks. In fact, major N inputs derived from inorganic fertilization (8.1-15.5 kg ha–1yr–1 and biological fixation (8.3-14.3 kg ha–1yr–1. On the other hand, plant removal constituted the most important output (17.7-25.6 kg ha–1yr–1. N losses in the drainage water were limited (3.0-9.5 kg ha–1yr–1 and the Centonara stream water was found to be unpolluted, with a nitrate concentration always below the EU limit for drinking water. The similar magnitude of total N inputs and outputs indicated that the crop management, especially the crop rotation and the N fertilization, in the Centonara watershed has reached a good level of

Fertilizers nitrogen balance under maizl and winter rye in lysimentric experiments

International Nuclear Information System (INIS)

Ionova, O.N.

1979-01-01

The balance of the labelled 15 N nitrogen fertilizers in lysimentric experiment carried oUt in the turf-podsolic medium loamy soil has been studied. The results of two year experiment (1976-1977) have shown that depending on the doses and time of introduction the use of fertilizer nitrogen by maize varied from 51 to 58 % and by winter rye from 52 to 59 %. Consolidation in the organic substance of soil constituted 18-26 and 17-33 %, respectively. The losses of fertilizer nitrogen varied (14-29 % under maize and 9-23 % under winter rye). Nitrogen losses as a result of atmospheric precipitation infiltration both under maize and winter rye occured mainly at the expense of nitrogen of soil and reached considerable dimensions (31 kg) only under conditions of exceeding moistening of 1976. The losses of fertilizer nitrogen caused by washing out do not exceed 1 % for two years. The main losses of fertilizer nitrogen occurred in the form of gaseous nitrogen compounds

Nitrogen Balance During Sweet Sorghum Cropping Cycle as Affected by Irrigation and Fertilization Rate

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Stella Lovelli

Full Text Available A two-year trial was carried out on sweet sorghum, grown in semi-arid environments of southern Europe. The trial was aimed to monitor the main components of the crop N-balance under different irrigation regimes and nitrogen fertilization rates, in factorial combination. A rainfed condition (only one watering soon after sowing was compared with a deficit irrigation regime and a full irrigation treatment (50 and 100% restoration of total crop water consumption, respectively. Crop nitrogen uptake always showed to be the highest N-balance components and was included in the range of 125-194 kg ha-1 during 1997-1998, with respect to the total shoot biomass, according to the nitrogen fertilization rate; consequently, it significantly reduced both nitrogen concentration in the soil solution and the total nitrogen loss due to drainage. Nitrogen concentration in the drainage water didn’t result to be strictly dependent on the rate of fertiliser applied but on the actual soil nitrogen content; the maximum registered value of total nitrogen lost by leaching was 1.9 kg ha-1. Differently, total nitrogen loss due to volatilisation was proportional to the amount of fertilizer applied; irrigation favourably reduced this kind of loss. The limited amount of Nvolatilisation loss was probably due to the neutral pH soil conditions; as an order of magnitude, referring to the highest fertilized but rainfed treatment, the utmost N-volatilisation loss was equal to 5.5 Kg ha-1, as an average over the three years, that is to say less than the 5% of the fertilization rate. A fertilisation rate of 120 Kg ha-1 of nitrogen, together with water application, generally produced a balance between crop N-uptake and total N-loss due to volatilisation and drainage (only the stalk biomass was considered in this calculation. Lower rates of fertilizing nitrogen, indeed, determined a depletion in the soil nitrogen content because of the high crop biomass and the strong N-uptake by the

Nitrogen Balance During Sweet Sorghum Cropping Cycle as Affected by Irrigation and Fertilization Rate

Directory of Open Access Journals (Sweden)

Michele Perniola

2011-02-01

Full Text Available A two-year trial was carried out on sweet sorghum, grown in semi-arid environments of southern Europe. The trial was aimed to monitor the main components of the crop N-balance under different irrigation regimes and nitrogen fertilization rates, in factorial combination. A rainfed condition (only one watering soon after sowing was compared with a deficit irrigation regime and a full irrigation treatment (50 and 100% restoration of total crop water consumption, respectively. Crop nitrogen uptake always showed to be the highest N-balance components and was included in the range of 125-194 kg ha-1 during 1997-1998, with respect to the total shoot biomass, according to the nitrogen fertilization rate; consequently, it significantly reduced both nitrogen concentration in the soil solution and the total nitrogen loss due to drainage. Nitrogen concentration in the drainage water didn’t result to be strictly dependent on the rate of fertiliser applied but on the actual soil nitrogen content; the maximum registered value of total nitrogen lost by leaching was 1.9 kg ha-1. Differently, total nitrogen loss due to volatilisation was proportional to the amount of fertilizer applied; irrigation favourably reduced this kind of loss. The limited amount of Nvolatilisation loss was probably due to the neutral pH soil conditions; as an order of magnitude, referring to the highest fertilized but rainfed treatment, the utmost N-volatilisation loss was equal to 5.5 Kg ha-1, as an average over the three years, that is to say less than the 5% of the fertilization rate. A fertilisation rate of 120 Kg ha-1 of nitrogen, together with water application, generally produced a balance between crop N-uptake and total N-loss due to volatilisation and drainage (only the stalk biomass was considered in this calculation. Lower rates of fertilizing nitrogen, indeed, determined a depletion in the soil nitrogen content because of the high crop biomass and the strong N-uptake by the

Computational modeling to predict nitrogen balance during acute metabolic decompensation in patients with urea cycle disorders.

Science.gov (United States)

MacLeod, Erin L; Hall, Kevin D; McGuire, Peter J

2016-01-01

Nutritional management of acute metabolic decompensation in amino acid inborn errors of metabolism (AA IEM) aims to restore nitrogen balance. While nutritional recommendations have been published, they have never been rigorously evaluated. Furthermore, despite these recommendations, there is a wide variation in the nutritional strategies employed amongst providers, particularly regarding the inclusion of parenteral lipids for protein-free caloric support. Since randomized clinical trials during acute metabolic decompensation are difficult and potentially dangerous, mathematical modeling of metabolism can serve as a surrogate for the preclinical evaluation of nutritional interventions aimed at restoring nitrogen balance during acute decompensation in AA IEM. A validated computational model of human macronutrient metabolism was adapted to predict nitrogen balance in response to various nutritional interventions in a simulated patient with a urea cycle disorder (UCD) during acute metabolic decompensation due to dietary non-adherence or infection. The nutritional interventions were constructed from published recommendations as well as clinical anecdotes. Overall, dextrose alone (DEX) was predicted to be better at restoring nitrogen balance and limiting nitrogen excretion during dietary non-adherence and infection scenarios, suggesting that the published recommended nutritional strategy involving dextrose and parenteral lipids (ISO) may be suboptimal. The implications for patients with AA IEM are that the medical course during acute metabolic decompensation may be influenced by the choice of protein-free caloric support. These results are also applicable to intensive care patients undergoing catabolism (postoperative phase or sepsis), where parenteral nutritional support aimed at restoring nitrogen balance may be more tailored regarding metabolic fuel selection.

Comparative study on intake, digestibility and nitrogen balance of ...

African Journals Online (AJOL)

Four Red Sokoto bucks of average weight 15±2kg were fed different legumes hay in a mixed diet to evaluate their feed intake, digestibility and nitrogen balance. Using 4×4 Latin Square arrangement. The four test diets contained Maize offal, Rice husk, Salt, Bone meal and Cotton seed cake.while,20% of Soybean, ...

Impacts of Human Induced Nitrogen Deposition on Ecosystem Carbon Sequestration and Water Balance in China

Science.gov (United States)

Sheng, M.; Yang, D.; Tang, J.; Lei, H.

2017-12-01

Enhanced plant biomass accumulation in response to elevated atmospheric CO2 concentration could dampen the future rate of increase in CO2 levels and associated climate warming. However, many experiments around the world reported that nitrogen availability could limit the sustainability of the ecosystems' response to elevated CO2. In the recent 20 years, atmospheric nitrogen deposition, primarily from fossil fuel combustion, has increased sharply about 25% in China and meanwhile, China has the highest carbon emission in the world, implying a large opportunity to increase vegetation greenness and ecosystem carbon sequestration. Moreover, the water balance of the ecosystem will also change. However, in the future, the trajectory of increasing nitrogen deposition from fossil fuel use is to be controlled by the government policy that shapes the energy and industrial structure. Therefore, the historical and future trajectories of nitrogen deposition are likely very different, and it is imperative to understand how changes in nitrogen deposition will impact the ecosystem carbon sequestration and water balance in China. We here use the Community Land Model (CLM 4.5) to analyze how the change of nitrogen deposition has influenced and will influence the ecosystem carbon and water cycle in China at a high spatial resolution (0.1 degree). We address the following questions: 1) what is the contribution of the nitrogen deposition on historical vegetation greenness? 2) How does the change of nitrogen deposition affect the carbon sequestration? 3) What is its influence to water balance? And 4) how different will be the influence of the nitrogen deposition on ecosystem carbon and water cycling in the future?

Nitrogen balance and ruminal assessment in male and female sheeps fed rations containing castor cake under different treatments

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Rafael Nogueira Furtado

2014-12-01

Full Text Available Was evaluated the influence of alternative methods of detoxification of castor cake on nitrogen balance and ruminal evaluation in sheep fed isocaloric and isonitrogenous experimental diets. Twenty sheep (ten males and ten females were used in five treatments (castor cake untreated, treated with limestone, treated with urea, treated with phosphate monodicalcium and autoclaved and four repetitions. For nitrogen balance we used a randomized block design, with the blocks according to the sex and the variables pH and ammonia nitrogen (NH3-N in the experimental design was split plot, with plots in the diets subplots and the collection times (0, 2, 5 and 8 hours postprandial.The treatments did not influence N intake, N urinary, urea and N-urea concentration in plasma. The Urinary N was higher in diet containing castor cake treated with phosphate monodicalcium (FOS when compared with those containing castor cake treated by autoclave (ACL. Already the nitrogen balance (BN was higher in diet ACL when compared to FOS diet. The pH and N-NH3 were within the normal range of sheep, being little affected by diet. Diets with methods of detoxification of castor cake promoted moderate changes in nitrogen balance with emphasis on the castor cake autoclaved and treated with limestone. The males sheep showed higher nitrogen balance than females.

Weight analyses and nitrogen balance assay in rats fed extruded ...

African Journals Online (AJOL)

Weight analyses and nitrogen balance assay in adult rats in raw and extruded African breadfruit (Treculia africana) based diets were carried out using response surface methodology in a central composite design. Process variables were feed composition (40 - 100 % African breadfruit, 0 - 5 % corn and 0 - 55 % soybean, ...

Nitrogen balances at farm level as a tool to monitor effects of agri-environment policy

NARCIS (Netherlands)

Brouwer, F.M.

1998-01-01

Nitrogen balances at farm level are an important tool for monitoring the effects of agri-environmental policy in the European Union. Nitrogen surpluses, defined as the difference between input and output flows, are a pressure indicator to link agricultural activities with environmental quality

Bakery waste in sheep diets: intake, digestibility, nitrogen balance and ruminal parameters

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Almira Biazon França

2012-01-01

Full Text Available The objective of the study was to evaluate the effects of bakery waste inclusion (0; 25; 50; 75 and 100%, DM basis in proportion to corn meal in the energetic mixture of the concentrate on intake, digestibility, nitrogen balance and ruminal parameters in sheep. Five male lambs with body weight of 30 kg were used in a 5 × 5 Latin square design. Experimental diets were composed of concentrate and Tifton 85 (Cynodon spp. hay in a 60:40 forage:concentrate ratio. The concentrate rations were composed of corn meal, soybean meal and bakery waste. The bakery waste:corn meal ratio corresponded to the inclusion of, approximately, 0, 7, 14, 22 and 30% (DM basis of bakery waste in the diet. There was no effect of bakery waste inclusion on the intake and digestibility of nutrients, nor on nitrogen balance, pH values or concentrations of volatile fatty acids. However, the ammonia nitrogen concentration showed negative linear response in relation to the level of inclusion, in which each increase of 1% bakery waste promoted reduction of 0.11 mg/dL in the concentration of ammonia nitrogen. This fact may be related to the increase in ruminal availability of energy, which allows greater use of ammonia for microbial growth. Bakery waste can replace corn meal in concentrate rations for sheep.

The carbon-nitrogen balance of the nodule and its regulation under elevated carbon dioxide concentration.

Science.gov (United States)

Libault, Marc

2014-01-01

Legumes have developed a unique way to interact with bacteria: in addition to preventing infection from pathogenic bacteria like any other plant, legumes also developed a mutualistic symbiotic relationship with one gender of soil bacteria: rhizobium. This interaction leads to the development of a new root organ, the nodule, where the differentiated bacteria fix for the plant the atmospheric dinitrogen (atmN2). In exchange, the symbiont will benefit from a permanent source of carbon compounds, products of the photosynthesis. The substantial amounts of fixed carbon dioxide dedicated to the symbiont imposed to the plant a tight regulation of the nodulation process to balance carbon and nitrogen incomes and outcomes. Climate change including the increase of the concentration of the atmospheric carbon dioxide is going to modify the rates of plant photosynthesis, the balance between nitrogen and carbon, and, as a consequence, the regulatory mechanisms of the nodulation process. This review focuses on the regulatory mechanisms controlling carbon/nitrogen balances in the context of legume nodulation and discusses how the change in atmospheric carbon dioxide concentration could affect nodulation efficiency.

Microbial Protein Production and Nitrogen Balance of Local Steer Fed Ammoniated Rice Straws Added

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H Hindratiningrum

2009-05-01

Full Text Available The objective of the experiment was to investigate the kind of energy source feedstuffs on nutrient balance and microbial protein synthesis in local male beef cattle fed with ammoniated rice straws Twenty steers Peranakan Ongole (PO with average age 1-2 years old were used. They were divided 5 groups based on initial body weight as block. Therefore, Completely Randomised Block Design (CBRD was used for this experiment. Data were analysed by analysis variance and continued honestly significant different (HSD to test the differences between means. The result showed that the range MCP and eficiency MCP were 154,61 g/d until 226,54 g/d and 54,08 gMCP/kg DOMR until 62,64 gMCP/kg DOMR. The range of nitrogen balance were 72,28 gram until 111,67 gram. MCP and efficiency MCP were not affected (P>0,05 by the treatments but balance of nitrogen was affected (P<0,05. Diet containing fresh cassava waste as energy source (R2 was lower (P<0,05 than R1 and R4 while between R1,R3 and R4 was similar. This results indicate that feed source of energy (rice brand, wet cassava waste, dry cassava waste and corn can be used in steers with rice straw ensilage as forage. (Animal Production 11(2: 116-121 (2009 Key Words : Microbial protein production, nitrogen balance, rice straw, ensilage

Protein intake, nitrogen balance and nutritional status in patients with Parkinson's disease; time for a change?

Science.gov (United States)

Zilli Canedo Silva, Maryanne; Carol Fritzen, Natali; de Oliveira, Marlon; Paes da Silva, Michel; Rasmussen Petterle, Ricardo; Teive, Hélio Afonso; de Mesquita Barros Almeida Leite, Christiane; Rabito, Estela Iraci; Madalozzo Schieferdecker, Maria Eliana; Carvalho, Mauricio

2015-06-01

To evaluate protein intake, nitrogen balance and nutritional status of clinically stable patients with Parkinson's disease (PD). A cross-sectional study of PD patients Hoehn-Yahr scale stage 1-3 and subjects with no neurologic disease (controls) matched for age and gender. All participants underwent a diet history interview, anthropometric measurements, bioelectrical impedance and food record over three non-consecutive days, including a weekend. A 24-hour urine collection and fasting venous blood sampling were collected from the participants for evaluation of creatinine clearance, creatinine height index and the nitrogen balance. The mean age of PD patients was 58.9 ± 12.8 year compared to 54.7 ± 12.6 year of the controls, P = 0.34. One third of PD group had symptoms of dysphagia and ingested less water and fibers when compared to controls. Calf circumference was small in PD group (35.5 ± 2.8 vs. 38.4 ± 3.5 cm, P = 0.012). Intake of nitrogen was significantly lower and nitrogen balance was negative in PD patients (-1.8 ± 3.9 vs. 1.1 ± 4.2 controls, P = 0.06). The antioxidants folate and vitamin E were consumed in small amounts in both groups, although significantly less in PD patients (P = 0.04 and 0.03, respectively). Daily intakes of protein of approximately 1.1 g/kg by clinically stable PD patients may not be enough to ensure a neutral calorie-nitrogen balance and muscle tissue conservation. Larger studies are necessary to provide a more comprehensive picture of PD patients' metabolic status. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Nitrogen balance, microbial protein synthesis and blood metabolites in fattening of male Bali cattle fed ration with different protein levels in smallholder farms

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P. K. Tahuk

2018-03-01

Full Text Available Research was aimed to determine nitrogen balance, microbial protein synthesis, and blood metabolites of male Bali cattle fattening fed ration with different protein level in smallholder farms North Central Timor, Province of East Timor Tenggara, Indonesia. The cattle used were 18 heads aged 2 to 2.5 years with initial body weight of 229.86±12.46 kg. The cattle were randomly divided into three treatment groups. The T0 group was given feed the same as traditional fattening cattle practices by farmers,T1 group fed ration containing 12% crude protein (CP and 72% total digestible nutrients (TDN, andT2 group fedration containing 15% CP and 72%TDN. Cattle were fed individually for 90 days and drinkingwater ad libitum. The data were analyzedby analysis of variance.Results of research indicated the nitrogen balance, and blood urea nitrogen between T1 and T2 were relatively similar, but those were higher (P<0.05 than T0 . In contrast, microbial proteins synthesis, and blood glucose at 0, 4, and 6 hours before and after feeding were relatively similar between the groups. Blood glucose of T2 at 2 hours after intake were higher (P <0.05 than T0, but was not different with T1 . It can be concluded, that the fattening maleBali cattle fed ration containing 12% CP and 72% TDNimprovedthe nitrogen balance and blood metabolites, butit was no positive effect on the microbial proteins and N synthesis.

The Effect of Nitrogen Cross-Over on Water Balance Measurements in Proton Exchange Membrane Fuel Cell Using Constant Temperature Anemometry

DEFF Research Database (Denmark)

Al Shakhshir, Saher; Berning, Torsten; Kær, Søren Knudsen

2016-01-01

A novel method to obtain an ad-hoc and real time electrical signal of the PEMFC water balance by employing a constant temperature hot wire anemometry has been developed by our fuel cell research group. In this work, the effect of nitrogen-cross over on this method is experimentally demonstrated...... by introducing 1% of nitrogen concentration to the dry and humidified hydrogen flow simulating the PEMFC anode outlet. The hot wire voltage is measured with and without nitrogen and it was slightly lower with the presence of nitrogen. The effect of the voltage reduction on the measured water balance is small...

Ingestive behavior and nitrogen balance of confined santa ines lambs fed diets containing soybean hulls.

Science.gov (United States)

Bastos, Milena Patrícia Viana; de Carvalho, Gleidson Giordano Pinto; Pires, Aureliano José Vieira; Silva, Robério Rodrigues; Filho, Antônio Eustáquio; Dos Santos, Edileusa de Jesus; Chagas, Daiane Maria Trindade; Barroso, Daniele Soares; Filho, George Abreu

2014-01-01

The objective of this study was to assess the effect of substituting corn with soybean hulls on the ingestive behavior and nitrogen balance of Santa Ines lambs. A total of 25 lambs with an initial body weight of 20±2 kg at approximately six months of age, sheltered individually in stalls (1.10 m×1.0 m), considering an entirely casual experimental delineation. Soybean hulls were substituted for corn at 0, 250, 500, 750, and 1,000 g/kg of dry matter (DM). The time spent feeding, ruminating, masticating, and resting was not affected by the substitution of corn with soybean hulls. In fact, the feeding efficiency in g DM/h and the rumination efficiency in g DM/bolus increased linearly with soybean hull substitution in the feed. Although the nitrogen balance was not altered by the use of soybean hulls as a substitute for corn in the diets of Santa Ines lambs, the N ingested and N digested expressed in g/d, N retained as a percentage of that ingested, and N retained as a percentage of that digested displayed quadratic behavior. In conclusion, corn can be substituted with soybean hulls up to 1,000 g/kg of dry matter in the concentrate, without changing the ingestive behavior and nitrogen balance.

Isotopic studies of nitrogen balance in a cracking clay

International Nuclear Information System (INIS)

Craswell, E.T.; Martin, A.E.

1975-01-01

The stable isotope 15 N was used to study the fate of nitrogen fertilizers applied to a black earth growing wheat. In a glasshouse experiment using soil packed at 56 per cent moisture (pF 2) into pots, added nitrate was almost completely recovered (mean, 98.8 +- 2.3 per cent) by soil and plant analysis. This experiment was repeated using 15 N-labelled ammonium as well as nitrate; mean recoveries at 15 weeks were 96.8 and 97 per cent respectively (+- 2.2 per cent at P 15 N measured, 97 and 96.8 per cent at 56 and 63 per cent moisture respectively. Fallow and planted systems were then studied in a gas lysimeter. During experiments lasting up to 14 weeks, gaseous losses as 15 N-labelled denitrification products were less than the equivalent of 0.2 μg nitrogen/g soil (the lower limit of detection with a mass spectrometer). Although analysis of plant and soil from the lysimeter in two experiments showed virtually quantitative recovery (99.7 and 97.05 per cent), small (0.16 per cent) losses of labelled ammonia into the lysimeter atmosphere were detected. The significance of these results is discussed in relation to the common finding of large deficits in nitrogen balance studies. (author)

Correlation Between Protein Intake and Nitrogen Balance of Surgical Patients in Anesthesiology and Intensive Care Installation, Sanglah General Hospital, Denpasar, Bali, Indonesia

Directory of Open Access Journals (Sweden)

Made Wiryana

2016-06-01

Full Text Available Background: A cell injury from surgical stress in a trauma or a non-trauma case will induce a hyper metabolic response in which the protein degradation increases, the somatic protein synthesis decreases and the amino acid catabolism increases. Thus, the pyper metabolic response contributes to nitrogen loss in urine. This response, without an adequate nutrition, will lead an iatrogenic malnutrition and deterioration. A balance nitrogen formula through urinary urea nitrogen is one of many nutrition evaluation methods. This method aids in evaluating the daily nutrition status and it can be the baseline data for daily intake. Objective: To find a correlation between the protein intake and the nitrogen balance of the surgical patients in anesthesiology and intensive care installation, Sanglah General Hospital, Denpasar, Bali. Methods: Fifty-one surgical patients with trauma and non-trauma cases were observed for their protein intake for 2-3 days continuously. Moreover, they were evaluated for their nitrogen balance based on the urinary urea nitrogen per 24 hours for 2-3 days. For statistical analysis, we utilized Shapiro-Francia, Shapiro-Wilk, Spearman Frank correlation, two-sample t test, and multivariate regression analysis in Strata SE 12.1. Results: The correlation between the protein intake and the nitrogen balance on the first day was ra=0.50 (p<0.05, on the second day ra=0.70 (p<0,05, and on the third day ra=0.740 (p<0,05. Conclusions: There is a correlation between the protein intake and the nitrogen balance of surgical patients in Anesthesiology and Intensive Care Installation Sanglah General Hospital Denpasar. 

Positive real balancing for nonlinear systems

NARCIS (Netherlands)

Ionescu, Tudor C.; Scherpen, Jacquelien M.A.; Ciuprina, G; Ioan, D

2007-01-01

We extend the positive real balancing procedure for passive linear systems to the nonlinear systems case. We show that, just like in the linear case, model reduction based on this technique preserves passivity.

Comparing Mass Balance and Adjoint-Based 4D-VAR Methods for Inverse Modeling of Nitrogen Dioxide Columns for Nitrogen Oxide Emissions

Science.gov (United States)

Cooper, M.; Martin, R.; Henze, D. K.

2016-12-01

Nitrogen oxide (NOx ≡ NO + NO2) emission inventories can be improved through top-down constraints provided by inverse modeling of observed nitrogen dioxide (NO2) columns. Here we compare two methods of inverse modeling for emissions of NOx from synthetic NO2 columns generated from known emissions using the GEOS-Chem chemical transport model and its adjoint. We treat the adjoint-based 4D-VAR approach for estimating top-down emissions as a benchmark against which to evaluate variations on the mass balance method. We find that the standard mass balance algorithm can be improved by using an iterative process and using finite difference to calculate the local sensitivity of a change in NO2 columns to a change in emissions, resulting in a factor of two reduction in inversion error. In a simplified case study to recover local emission perturbations, horizontal smearing effects due to NOx transport were better resolved by the adjoint-based approach than by mass balance. For more complex emission changes that reflect real world scenarios, the iterative finite difference mass balance and adjoint methods produce similar top-down inventories when inverting hourly synthetic observations, both reducing the a priori error by factors of 3-4. Inversions of data sets that simulate satellite observations from low Earth and geostationary orbits also indicate that both the mass balance and adjoint inversions produce similar results, reducing a priori error by a factor of 3. As the iterative finite difference mass balance method provides similar accuracy as the adjoint-based 4D-VAR method, it offers the ability to efficiently estimate top-down emissions using models that do not have an adjoint.

Nitrogen balance along a northern boreal forest fire chronosequence.

Science.gov (United States)

Palviainen, Marjo; Pumpanen, Jukka; Berninger, Frank; Ritala, Kaisa; Duan, Baoli; Heinonsalo, Jussi; Sun, Hui; Köster, Egle; Köster, Kajar

2017-01-01

Fire is a major natural disturbance factor in boreal forests, and the frequency of forest fires is predicted to increase due to climate change. Nitrogen (N) is a key determinant of carbon sequestration in boreal forests because the shortage of N limits tree growth. We studied changes in N pools and fluxes, and the overall N balance across a 155-year non stand-replacing fire chronosequence in sub-arctic Pinus sylvestris forests in Finland. Two years after the fire, total ecosystem N pool was 622 kg ha-1 of which 16% was in the vegetation, 8% in the dead biomass and 76% in the soil. 155 years after the fire, total N pool was 960 kg ha-1, with 27% in the vegetation, 3% in the dead biomass and 69% in the soil. This implies an annual accumulation rate of 2.28 kg ha-1 which was distributed equally between soil and biomass. The observed changes in N pools were consistent with the computed N balance +2.11 kg ha-1 yr-1 over the 155-year post-fire period. Nitrogen deposition was an important component of the N balance. The biological N fixation increased with succession and constituted 9% of the total N input during the 155 post-fire years. N2O fluxes were negligible (≤ 0.01 kg ha-1 yr-1) and did not differ among post-fire age classes. The number and intensity of microbial genes involved in N cycling were lower at the site 60 years after fire compared to the youngest and the oldest sites indicating potential differences in soil N cycling processes. The results suggest that in sub-arctic pine forests, the non-stand-replacing, intermediate-severity fires decrease considerably N pools in biomass but changes in soil and total ecosystem N pools are slight. Current fire-return interval does not seem to pose a great threat to ecosystem productivity and N status in these sub-arctic forests.

Nitrogen emissions from broilers measured by mass balance over eighteen consecutive flocks.

Science.gov (United States)

Coufal, C D; Chavez, C; Niemeyer, P R; Carey, J B

2006-03-01

Emission of nitrogen in the form of ammonia from poultry rearing facilities has been an important topic for the poultry industry because of concerns regarding the effects of ammonia on the environment. Sound scientific data is needed to accurately estimate air emissions from poultry operations. Many factors, such as season of the year, ambient temperature and humidity, bird health, and management practices can influence ammonia volatilization from broiler rearing facilities. Precise results are often difficult to attain from commercial facilities, particularly over long periods of time. Therefore, an experiment was conducted to determine nitrogen loss from broilers in a research facility under conditions simulating commercial production for 18 consecutive flocks. Broilers were reared to 40 to 42 d of age and fed diets obtained from a commercial broiler integrator. New rice hulls were used for litter for the first flock, and the same litter was recycled for all subsequent flocks with caked litter removed between flocks. All birds, feeds, and litter materials entering and leaving the facility were quantified, sampled, and analyzed for total nitrogen content. Nitrogen loss was calculated by the mass balance method in which loss was equal to the difference between the nitrogen inputs and the nitrogen outputs. Nitrogen partitioning as a percentage of inputs averaged 15.29, 6.84, 55.52, 1.27, and 21.08% for litter, caked litter, broiler carcasses, mortalities, and nitrogen loss, respectively, over all eighteen flocks. During the production of 18 flocks of broilers on the same recycled litter, the average nitrogen emission rate was calculated to range from 4.13 to 19.74 g of N/ kg of marketed broiler (grams of nitrogen per kilogram) and averaged 11.07 g of N/kg. Nitrogen loss was significantly (P broiler grow-out facilities varies significantly on a flock-to-flock basis.

Ingestive Behavior and Nitrogen Balance of Confined Santa Ines Lambs Fed Diets Containing Soybean Hulls

Directory of Open Access Journals (Sweden)

Milena Patrícia Viana Bastos

2014-01-01

Full Text Available The objective of this study was to assess the effect of substituting corn with soybean hulls on the ingestive behavior and nitrogen balance of Santa Ines lambs. A total of 25 lambs with an initial body weight of 20±2 kg at approximately six months of age, sheltered individually in stalls (1.10 m×1.0 m, considering an entirely casual experimental delineation. Soybean hulls were substituted for corn at 0, 250, 500, 750, and 1,000 g/kg of dry matter (DM. The time spent feeding, ruminating, masticating, and resting was not affected by the substitution of corn with soybean hulls. In fact, the feeding efficiency in g DM/h and the rumination efficiency in g DM/bolus increased linearly with soybean hull substitution in the feed. Although the nitrogen balance was not altered by the use of soybean hulls as a substitute for corn in the diets of Santa Ines lambs, the N ingested and N digested expressed in g/d, N retained as a percentage of that ingested, and N retained as a percentage of that digested displayed quadratic behavior. In conclusion, corn can be substituted with soybean hulls up to 1,000 g/kg of dry matter in the concentrate, without changing the ingestive behavior and nitrogen balance.

Analysis of Financial Position Based on the Balance Sheet

OpenAIRE

Spineanu-Georgescu Luciana

2011-01-01

Analysis of financial position based on the balance sheet is mainly aimed at assessing the extent to which financial structure chosen by the firm, namely, financial resources, covering the needs reflected in the balance sheet financed. This is done through an analysis known as horizontal analysis balance sheet financial imbalances.

Water-bearing explosive containing nitrogen-base salt

Energy Technology Data Exchange (ETDEWEB)

Dunglinson, C.; Lyerly, W.M.

1968-10-21

A water-bearing explosive composition consists of an oxidizing salt component, a fuel component, and water. A sensitizer is included having an oxygen balance more positive than -150%, and consisting of a salt of an inorganic oxidizing acid and of an acyclic nitrogen base having no more than 2 hydrogen atoms bonded to the basic nitrogen and up to 3 carbons per basic nitrogen, and/or of a phenyl amine. 41 claims.

Nitrogen Balance and Protein Requirements for Critically Ill Older Patients

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Roland N. Dickerson

2016-04-01

Full Text Available Critically ill older patients with sarcopenia experience greater morbidity and mortality than younger patients. It is anticipated that unabated protein catabolism would be detrimental for the critically ill older patient. Healthy older subjects experience a diminished response to protein supplementation when compared to their younger counterparts, but this anabolic resistance can be overcome by increasing protein intake. Preliminary evidence suggests that older patients may respond differently to protein intake than younger patients during critical illness as well. If sufficient protein intake is given, older patients can achieve a similar nitrogen accretion response as younger patients even during critical illness. However, there is concern among some clinicians that increasing protein intake in older patients during critical illness may lead to azotemia due to decreased renal functional reserve which may augment the propensity towards worsened renal function and worsened clinical outcomes. Current evidence regarding protein requirements, nitrogen balance, ureagenesis, and clinical outcomes during nutritional therapy for critically ill older patients is reviewed.

Nitrogen balance in a goat farm producing milk in the county of Barva, Costa Rica

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José P. Jiménez

2014-06-01

Full Text Available The objective of this study was to quantify the use of N in a goat milk producer farm located in the province of Heredia. Data such as feed purchases, milk sales, pur¬chase and removal of animals was compiled and analyzed between January and December 2012. In order to evaluate the use of N, three indicators that allowed analyzing farm efficiency were used. Total number of animals was 102. Annual milk production was 22.417,5 kg. The farm imported 729,8 kg of nitrogen, of which 71% came from feed and only 29% from fertilizers. Farm exported 113,3 kg of nitrogen, of which 85,3% was exported as milk and only 14,7% as animals. The farm imported 38,7 g of N per kg of milk produced. In general, N balance was positive for all farms, indicating that more N entered the farm that came out in the form of product, showing that up to 84,5% of all imported N remained in the farms. Our results suggests that strategies to reduce N excretion should be developed, including improvements in the diet, since the largest N input is through imported feed.

Nitrogen balance during growth of cauliflower

NARCIS (Netherlands)

Everaarts, A.P.

2000-01-01

The potential for loss of nitrogen to the environment during growth of cauliflower was investigated. A comparison was made between cauliflower growth and nitrogen uptake without, and with, nitrogen application of the recommended amount (=225 kg ha-1 minus mineral nitrogen in the soil layer 0–60 cm,

Nitrogen balance as a tool to assess nitrogen mineralized from winery wastes under different irrigation strategies

Science.gov (United States)

Requejo, Maria Isabel; Castellanos, Maria Teresa; Villena, Raquel; Ribas, Francisco; Jesús Cabello, Maria; Arce, Augusto; Cartagena, Maria Carmen

2013-04-01

Grape marc is a by-product coming from the winery industry, composed of skins, seeds and stalks generated during the crushing process. In Spain, large quantities of wine are produced every year (3,610,000 tonnes in 2010 (FAO, 2010)) with the consequent waste generation. With an adequate composting treatment, this waste can be applied to soils as a source of nutrients and organic matter. Compost N forms added to soil are mostly organic N forms, so organic N can be mineralized during the crop period and thus be taken up by the plants, immobilised, or leached. Compost N mineralization depends on factors such as compost C/N ratio but also on climate conditions. Estimation of N mineralization is necessary to optimise crop yield and minimize the risk of N losses to the environment, especially in zones vulnerable to nitrate pollution. The aim of this work was to assess mineralized N during the crop season when applying grape marc compost as fertilizer in a melon crop cultivated under different drip irrigation rates. A nitrogen balance in field conditions was carried out with three different doses of compost: 0 (D0), 6.7 (D1), 13.3 (D2) and 20 T/ha (D3); and two irrigation rates (100% ETc and 120% ETc). The field experiment was carried out in Ciudad Real, designated "vulnerable zone" by the "Nitrates Directive" 91/676/CEE. The soil was a shallow sandy-loam (Petrocalcic Palexeralfs), with 0.6 depth and a discontinuous petrocalcic horizon between 0.6 and 0.7 m. Nitrogen plant uptake and nitrate losses were measured weekly; mineral N in soil was determined before compost addition and at the end of the crop cycle. An estimation of soil mineralized N during the crop season using nitrogen balance is presented. Results are compared with data obtained in laboratory conditions. Acknowledgements: This project has been supported by INIA-RTA2010-00110-C03-01.

Energy balance of maize production in Brazil: the energetic constraints of a net positive outcome

Energy Technology Data Exchange (ETDEWEB)

Soares, Luis Henrique de Barros; Alves, Bruno Jose Rodrigues; Urquiaga, Segundo

2008-07-01

Among the factors used to analyze and to establish the sustainability of a whole agricultural production system, the energy balance is one of the most powerful and robust. The maize production in Brazil is surely the reflex of an energy intensive system that demands many field operations and heavy fertilizer applications, notably nitrogen in urea form. This work presents an energy balance of this major crop adjusted to the Brazilian conditions of cultivation. The input components were grouped based on their energy contents, and the possible improvements in the agricultural practices that could improve energy balance and net energy withdrawn from the farming were considered. The replacement of N synthetic fertilizer by biological nitrogen fixation, whether the process is directly carried out by endophytic diazotroph bacteria or by means of a N{sub 2}- fixing legume culture planted before the main crop as a green-manure is also discussed. (author)

Geochemical mass balance for sulfur- and nitrogen-bearing acid components: Eastern United States

International Nuclear Information System (INIS)

Bischoff, W.D.; Mackenzie, F.T.; Paterson, V.L.

1984-01-01

The impact on a geographical region of SO 2 and nitrogen oxides (NO /SUB x/ ) emissions to the atmosphere because of man's activities (e.g., burning of fossil fuels and smelting of sulfide ores) usually has not been considered in terms of a regional geochemical mass balance model. Mass balance models, however, have been employed extensively on a global scale. The models evaluate reservoir sizes, processes and fluxes associated with the transfer of a substance within a system of interest. The models may be steady- or transient-state, and include assessment of historical (geologic), present and future data and processes. In this chapter a geochemical mass balance model is applied to constituents of acid precipitation (H + , NO - 3 and SO 2- ) to evaluate the impact of acid precipitation on the eastern United States

Effect of water intake on the nitrogen balance of sheep fed a low or a ...

African Journals Online (AJOL)

Effect of water intake on the nitrogen balance of sheep fed a low or a medium protein diet. JG van der Walt, EA Boomker, A Meintjes, WA Schultheiss. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

Modeling the effects of anadromous fish nitrogen on the carbon balance of riparian forests in central Idaho

Science.gov (United States)

Noble Stuen, A. J.; Kavanagh, K.; Wheeler, T.

2010-12-01

climate change in order to develop a realistic prediction for the two treatments. Results from objective 1 indicate that Biome-BGC can adequately simulate the study site: measured leaf area index (LAI) is not significantly different from maximum LAI predicted by the model. Results from objective 2 indicate that marine-derived nitrogen may increase NEE by up to eight times relative to no nutrient addition, whereas the continued loss of marine nitrogen may lead to a decrease in NEE relative to historical conditions. MDN may become even more important to maintaining a positive carbon balance under a climate warming scenario: model results show a decline in NEE with climate change, which is mitigated by the presence of the added marine nitrogen. Understanding the long-term impacts of marine-derived nutrients to inland Idaho watersheds will help inform forest management and nutrient-loss mitigation efforts.

Parenteral structured triglyceride emulsion improves nitrogen balance and is cleared faster from the blood in moderately catabolic patients.

Science.gov (United States)

Kruimel, J W; Naber, T H; van der Vliet, J A; Carneheim, C; Katan, M B; Jansen, J B

2001-01-01

Most postoperative patients lose net protein mass, which reflects loss of muscle tissue and organ function. Perioperative parenteral nutrition may reduce the loss of protein, but in general, with conventional lipid emulsions a waste of protein still remains. We compared the effects on nitrogen balance of an emulsion containing structured triglycerides, a new type of synthesized triglycerides, with an emulsion of a physical mixture of medium- and long-chain triglycerides as part of parenteral feeding in moderately catabolic patients. The first 5 days after placement of an aortic prosthesis patients received total parenteral nutrition (TPN) providing 0.2 g of nitrogen per kg body weight per day; energy requirement was calculated using Harris and Benedict's equation, adding 300 kcal per day for activity. Twelve patients were treated with the structured triglyceride emulsion and 13 patients with the emulsion of the physical mixture of medium- and long-chain triglycerides. The design was a randomized, double-blind parallel study. In the patients who completed the study, the mean cumulative nitrogen balance over the first 5 postoperative days was -8+/-2 g in 10 patients on the structured triglyceride emulsion and -21+/-4 g in 9 patients on the emulsion of the physical mixture of medium- and long-chain triglycerides; the mean difference was 13 g of nitrogen (95% confidence interval 4 to 22, p = .015) in favor of the structured triglyceride emulsion. On the first postoperative day serum triglyceride and plasma medium-chain free fatty acid levels increased less during infusion of the structured triglyceride emulsion than with the physical mixture emulsion. The parenteral structured triglyceride emulsion improves the nitrogen balance and is cleared faster from the blood, compared with the emulsion of the physical mixture of medium- and long-chain triglycerides, in moderately catabolic patients.

Recommended ingestion of indispensable amino acids to young men . A study using stable isotopes, plasmatic amino acids and nitrogen balance

International Nuclear Information System (INIS)

Marchini, J.S.

1992-01-01

It has been previously stated that the minimum physiological recommendations for the indispensable amino acids in health adults, as proposed by FAO/WHO/UNU in 1985, are far too low, except for the methionine. An amino acid stable isotopic kinetic study was conducted to seek further experimental support to this hypothesis. Twenty healthy young men received an l-amino acid based diet, supplying 140 mg N.kg -1 .d -1 , patterned on egg protein for 1 week, then for 3 weeks either i) a pattern based on current international recommendations (FAO diet, n=7), ii) a the tentative Laboratory of Human Nutrition of the Massachusetts Institute of Technology, new amino acid recommendation pattern (MIT diet, n=7) or iii) again the egg hen pattern (EGG diet, n=6). All subjects were again studied for one final, consecutive week of the egg diet. At the end of the initial week, at the first and third week with the three experimental diets,and after three days following the return of the egg diet, an 8 h primed continuous intravenous infusion with l- 13 C-leucine was conducted (3 h, fast, 5 h fed - while subjects received hourly meals supplying the equivalent of 5/12 total daily intake). Estimation of leucine balance were carried out with measurements plasma free amino acids changes. Daily nitrogen balances were obtained through the study. Interpretation of plasma amino acids profile, and changes of leucine kinetics balances, indicated that the FAO diet was not able to maintain amino acids homeostasis whereas the MIT and the egg diets sustained body amino acids equilibrium with a positive amino acid balance. nitrogen balances tended to be more negative with the FAO diet but failed to show statistically significant differences among the three diets. The finding point out that it would be prudent to use the new, tentative recommended amino acid pattern (MIT diet 0 as the minimum physiological amino acid needs of healthy human adults (author)

Positive well-being and work-life balance among UK railway staff

OpenAIRE

Fan, Jialin; Smith, Andrew

2017-01-01

Failure to manage the well-being and work-life balance of railway workers\\ud may result in an increased risk to train safety and employees’ health. This article\\ud reports the findings of a study that measured positive well-being and\\ud work-life balance, and identified the factors affecting these among UK railway\\ud staff. On the whole, staff who perceived high levels of control and support had\\ud a better work-life balance and an increased sense of well-being. A positive\\ud personality was ...

Nitrogen balance and milk composition of dairy cows fed urea and soybean meal and two protein levels using sugar cane based diets

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Luís Henrique Andreucci Conti

2014-12-01

Full Text Available The aim of the study was to evaluate the effect of feeding two levels of crude protein (CP (low: 142 g CP/kg DM; and high: 156 g CP/kg DM and two nitrogen sources (soybean meal and urea to dairy cows using sugar cane as forage on microbial protein synthesis, the composition of the milk nitrogen fraction, nitrogen (N balance and blood parameters. Twelve Holstein cows with an average milk yield of 22.0 ± 2.3 kg/day, and with 235 ± 40 days in milk were included in this study. The animals were grouped into three balanced and contemporary 4x4 Latin squares for an experimental period of 21 days. On the 15th day of each period, milk and urine samples were collected for microbial protein synthesis determination. Total excretion of urine (L/day, milk urea nitrogen (MUN and blood urea were higher for the diets with high CP, regardless of the nitrogen source. Nitrogen efficiency was higher for cows fed diets with low CP. Cows in the final third of lactation can be fed diets with reduced CP levels, regardless of the nitrogen source, soybean meal or urea, without influencing the synthesis of microbial protein or the composition of the nitrogen fraction of milk.

The Crc protein inhibits the production of polyhydroxyalkanoates in Pseudomonas putida under balanced carbon/nitrogen growth conditions.

Science.gov (United States)

La Rosa, Ruggero; de la Peña, Fernando; Prieto, María Axiliadora; Rojo, Fernando

2014-01-01

Pseudomonas putida synthesizes polyhydroxyalkanoates (PHAs) as storage compounds. PHA synthesis is more active when the carbon source is in excess and the nitrogen source is limiting, but can also occur at a lower rate under balanced carbon/nitrogen ratios. This work shows that PHA synthesis is controlled by the Crc global regulator, a protein that optimizes carbon metabolism by inhibiting the expression of genes involved in the use of non-preferred carbon sources. Crc acts post-transcriptionally. The mRNAs of target genes contain characteristic catabolite activity (CA) motifs near the ribosome binding site. Sequences resembling CA motifs can be predicted for the phaC1 gene, which codes for a PHA polymerase, and for phaI and phaF, which encode proteins associated to PHA granules. Our results show that Crc inhibits the translation of phaC1 mRNA, but not that of phaI or phaF, reducing the amount of PHA accumulated in the cell. Crc inhibited PHA synthesis during exponential growth in media containing a balanced carbon/nitrogen ratio. No inhibition was seen when the carbon/nitrogen ratio was imbalanced. This extends the role of Crc beyond that of controlling the hierarchical utilization of carbon sources and provides a link between PHA synthesis and the global regulatory networks controlling carbon flow. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

Sustainable intensification and extensification of cropping system for biorefinery in Denmark-what does the nitrogen balance say?

DEFF Research Database (Denmark)

Manevski, Kiril; Lærke, Poul Erik; Jørgensen, Uffe

Establishing an environment-friendly industrial biorefinery production requires resource efficient agroecosystems with low losses to the environment, especially of nitrogen (N). This work reports the first field-based N losses and balances for agro-ecosystems optimised for biomass production...

Digestibility and nitrogen balance of diets containing non conventional vegetable proteins fed to pigs of genetic strains suitable for outdoor systems

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L. Sardi

2010-04-01

Full Text Available The study was carried out to evaluate on growing pigs kept in metabolism crates, either belonging to a “traditional” cross-breed (Duroc x Large White – DLW or a local breed (Cinta Senese – CS, the digestibility and the nitrogen balance of non-conventional vegetable protein sources (field beans, pea and sunflower cake when compared to soybean meal. The four diets were formulated so as to supply the same crude protein amount. CS pigs showed lower apparent digestibility coefficients (ADCs for crude protein (81,38% vs 82,65% and crude fibre (35,97% vs 40,65%. Nitrogen balance was more favourable in DLW pigs (32,12% vs 19,67% which showed a higher nitrogen retention (+69%.With respect to the protein source, no differences were observed for nitrogen balance. Sunflower diet showed the higher ADC for ether extract (+20% compared with soybean diet. Crude fibre digestibility was lowered in sunflower (-33% and field beans (-13% diets. Sunflower and field beans diets showed the lowest gross energy digestibility coefficients. Field pea diet had the highest ADC for crude fibre (+ 12% leading to ADCs for organic matter and gross energy comparable to those of soybean meal. It is concluded that field bean, sunflower cake and field pea could be considered as valuable non-conventional protein sources in swine nutrition.

Slope position and Soil Lithological Effects on Live Leaf Nitrogen Concentration.

Science.gov (United States)

Szink, I.; Adams, T. S.; Orr, A. S.; Eissenstat, D. M.

2017-12-01

Soil lithology has been shown to have an effect on plant physiology from the roots to the leaves. Soils at ridgetop positions are typically more shallow and drier than soils at valley floor positions. Additionally, sandy soils tend to have a much lower water holding capacity and can be much harder for plants to draw nutrients from. We hypothesized that leaves from trees in shale derived soil at ridgetop positions will have lower nitrogen concentration than those in valley floor positions, and that this difference will be more pronounced in sandstone derived soils. This is due to the movement of nitrogen through the soil in a catchment, and the holding and exchange capacities of shale and sandstone lithologies. To test this, we collected live leaves using shotgun sampling from two locations in Central Pennsylvania from the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO); one location where soils are underlain by the Rose Hill Shale, and one from where soils are underlain by the Tuscarora Sandstone formation. We then measured, dried, and massed in order to determine specific leaf area (SLA). Afterwards, we powderized the leaves to determined their C:N ratio using a CE Instruments EA 1110 CHNS-O elemental Analyzer based on the "Dumas Method". We found that live leaves of the same species at higher elevations had lower nitrogen concentrations than those at lower elevations, which is consistent with our hypothesis. However, the comparison of leaves from all species in the catchment is not as strong, suggesting that there is a species specific effect on nitrogen concentration within leaves. We are currently processing additional leaves from other shale and sandstone sites. These results highlight the effect of abiotic environments on leaf nutrient concentrations, and the connection between belowground and aboveground tree physiology.

The assessment of nitrogen balance under flooding and saturation circumstances using N-15

Energy Technology Data Exchange (ETDEWEB)

Abouseeda, M; Khater, A [National Research Centre, Soil and Water Dept., Cairo (Egypt); Soliman, S [Atomic Energy Authority, Soil and Water Dept., P.O.Box 13759 Cairo (Egypt)

1995-10-01

The use{sup 15} N- balance techniques has already identified N-loss as a major problem in lowland rice management. Ammonium sulphate labelled with 5% N-15 atom ex. as a basal fertilized through special column in order to study the effect of flooding and saturation condition on the potential loss of nitrogen fertilizer. Rice straw at a rate of 1% was incorporated with the soil in order to study the role of rice straw (as a source of organic matter) on N-loss. Results show that the application of rice straw under flooding condition resulted in an increase of the biomass. It was observed that flooding circumstances may reduce the loss of nitrogen. Since N-recovery under flood and saturation rhizosphere (with plant) conditions were about 75% and 56%, respectively. The effect of rice root (rhizosphere) on nitrification has been observed. Results of flood and non flood rhizossphere show that the nitrogen recovery were about 75% and 86%, respectively. Results show an indirect evidence that the process of rhizosphere nitrification denitrification resulted in a significant amount of N-loss.It is evident that deep placement and flooded condition proved to be an effective means of reducing the potential of N-loss. 1 fig., 3 tabs.

The assessment of nitrogen balance under flooding and saturation circumstances using N-15

International Nuclear Information System (INIS)

Abouseeda, M.; Khater, A.; Soliman, S.

1995-01-01

The use 15 N- balance techniques has already identified N-loss as a major problem in lowland rice management. Ammonium sulphate labelled with 5% N-15 atom ex. as a basal fertilized through special column in order to study the effect of flooding and saturation condition on the potential loss of nitrogen fertilizer. Rice straw at a rate of 1% was incorporated with the soil in order to study the role of rice straw (as a source of organic matter) on N-loss. Results show that the application of rice straw under flooding condition resulted in an increase of the biomass. It was observed that flooding circumstances may reduce the loss of nitrogen. Since N-recovery under flood and saturation rhizosphere (with plant) conditions were about 75% and 56%, respectively. The effect of rice root (rhizosphere) on nitrification has been observed. Results of flood and non flood rhizossphere show that the nitrogen recovery were about 75% and 86%, respectively. Results show an indirect evidence that the process of rhizosphere nitrification denitrification resulted in a significant amount of N-loss.It is evident that deep placement and flooded condition proved to be an effective means of reducing the potential of N-loss. 1 fig., 3 tabs

Balancing carbon/nitrogen ratio to improve nutrients removal and algal biomass production in piggery and brewery wastewaters.

Science.gov (United States)

Zheng, Hongli; Liu, Mingzhi; Lu, Qian; Wu, Xiaodan; Ma, Yiwei; Cheng, Yanling; Addy, Min; Liu, Yuhuan; Ruan, Roger

2018-02-01

To improve nutrients removal from wastewaters and enhance algal biomass production, piggery wastewater was mixed with brewery wastewaters. The results showed that it was a promising way to cultivate microalga in piggery and brewery wastewaters by balancing the carbon/nitrogen ratio. The optimal treatment condition for the mixed piggery-brewery wastewater using microalga was piggery wastewater mixed with brewery packaging wastewater by 1:5 at pH 7.0, resulting in carbon/nitrogen ratio of 7.9, with the biomass concentration of 2.85 g L -1 , and the removal of 100% ammonia, 96% of total nitrogen, 90% of total phosphorus, and 93% of chemical oxygen demand. The application of the established strategies can enhance nutrient removal efficiency of the wastewaters while reducing microalgal biomass production costs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Robust balancing and position control of a single spherical wheeled mobile platform

OpenAIRE

Yavuz, Fırat; Yavuz, Firat; Ünel, Mustafa; Unel, Mustafa

2016-01-01

Self-balancing mobile platforms with single spherical wheel, generally called ballbots, are suitable example of underactuated systems. Balancing control of a ballbot platform, which aims to maintain the upright orientation by rejecting external disturbances, is important during station keeping or trajectory tracking. In this paper, acceleration based balancing and position control of a single spherical wheeled mobile platform that has three single-row omniwheel drive m...

Nitrogen balance, plasma free amino acid concentrations and urinary orotic acid excretion during long-term fasting in cats.

Science.gov (United States)

Biourge, V; Groff, J M; Fisher, C; Bee, D; Morris, J G; Rogers, Q R

1994-07-01

The purpose of this study was to ascertain the changes in nitrogen balance, plasma free amino acid concentrations, urinary orotic acid excretion and body weight during long-term fasting in adult obese cats. Results from eight cats that fasted rather than eat an unpalatable diet are reported. After 5 to 6 wk of weight loss, six of the eight cats developed signs of hepatic lipidosis, and the livers of all cats were severely infiltrated with lipids. Cats lost (mean +/- SE) 33.2 +/- 1.4% of their pre-fasting body weight. Mean nitrogen balance (+/- SE) was -547 +/- 54 mg.d-1.kg-2/3 for the first week, and then the net nitrogen losses decreased to a plateau (-303 +/- 52 mg.d-1.kg-2/3) after 4 wk. Fasting was associated with a decrease in plasma concentration of essential amino acids. When plasma amino acid concentrations were considered individually, concentrations of alanine, methionine, taurine, citrulline, arginine and tryptophan decreased the most (> or = 50%), whereas concentrations of glutamine, glutamate and ornithine significantly increased. Orotic acid was not detected in the urine during the fast. After 1 wk of fasting, obese cats had reduced nitrogen excretion, but not to the same extent as has been shown in obese humans or obese rats. It is suggested that the availability of several amino acids may become limiting for liver protein synthesis during fasting and that these deficiencies may contribute to the development of hepatic lipidosis. Orotic acid was not linked to hepatic lipidosis caused by fasting in cats.

Impacts of climate and management on water balance and nitrogen leaching from montane grassland soils

Science.gov (United States)

Fu, Jin; Gasche, Rainer; Wang, Na; Lu, Haiyan; Butterbach-Bahl, Klaus; Kiese, Ralf

2017-04-01

The impacts of climate and management on the water balance and nutrient leaching of montane grasslands have rarely been investigated, though such ecosystems may represent a major source for ground and surface water nitrates. In this study nitrogen (nitrate, ammonium, dissolved organic nitrogen) and dissolved organic carbon leaching as well as water balance components (precipitation, evapotranspiration, and groundwater recharge) were quantified (2012-2014) by means of replicated (N=3 per site/ treatment) measurements of weighable grassland lysimeters (1 m2 area, 1.2 m soil depth) at three sites (E860: 860 m a.s.l., E770: 770 m a.s.l. and E600: 600 m a.s.l.) in the pre-alpine region of S-Germany. Two grassland management strategies were investigated: a) intensive management with 5 cuts per year and cattle slurry application rates of 280 kg N ha-1 yr-1, and b) extensive management with 3 cuts per year and cattle slurry application rates of 56 kg N ha-1 yr-1. Our results show that at E600, the site with highest air temperature (8.6 °C) and lowest precipitation (981.9 mm), evapotranspiration losses were 100.7 mm higher as at the E860 site, i.e. the site with lowest mean annual air temperature (6.5 °C) and highest precipitation (1359.3 mm). On the other hand groundwater recharge was substantial lower at E600 (-440.9 mm) as compared to E860. Compared to climate, impacts of grassland management on water balance components were negligible. However, intensive management significantly increased mean total nitrogen leaching rates across sites as compared to extensive management from 2.6 kg N ha-1 year-1 (range: 0.5-6.0 kg N ha-1 year-1) to 4.8 kg N ha-1 year-1 (range: 0.9-12.9 kg N ha-1 year-1). N leaching losses were dominated by nitrate (64.7 %) and equally less by ammonium (14.6 %) and DON (20.7 %). The rather low rates of N leaching (0.8 - 6.9 % of total applied N) suggest a highly efficient nitrogen uptake by plants as measured by plant total N content at harvest

Bounded real and positive real balanced truncation using Σ-normalised coprime factors

NARCIS (Netherlands)

Trentelman, H.L.

2009-01-01

In this article, we will extend the method of balanced truncation using normalised right coprime factors of the system transfer matrix to balanced truncation with preservation of half line dissipativity. Special cases are preservation of positive realness and bounded realness. We consider a half

Permafrost carbon−climate feedback is sensitive to deep soil carbon decomposability but not deep soil nitrogen dynamics

Science.gov (United States)

Koven, Charles D.; Lawrence, David M.; Riley, William J.

2015-01-01

Permafrost soils contain enormous amounts of organic carbon whose stability is contingent on remaining frozen. With future warming, these soils may release carbon to the atmosphere and act as a positive feedback to climate change. Significant uncertainty remains on the postthaw carbon dynamics of permafrost-affected ecosystems, in particular since most of the carbon resides at depth where decomposition dynamics may differ from surface soils, and since nitrogen mineralized by decomposition may enhance plant growth. Here we show, using a carbon−nitrogen model that includes permafrost processes forced in an unmitigated warming scenario, that the future carbon balance of the permafrost region is highly sensitive to the decomposability of deeper carbon, with the net balance ranging from 21 Pg C to 164 Pg C losses by 2300. Increased soil nitrogen mineralization reduces nutrient limitations, but the impact of deep nitrogen on the carbon budget is small due to enhanced nitrogen availability from warming surface soils and seasonal asynchrony between deeper nitrogen availability and plant nitrogen demands. Although nitrogen dynamics are highly uncertain, the future carbon balance of this region is projected to hinge more on the rate and extent of permafrost thaw and soil decomposition than on enhanced nitrogen availability for vegetation growth resulting from permafrost thaw. PMID:25775603

Calibration and validation of SWAT model for estimating water balance and nitrogen losses in a small agricultural watershed in central Poland

Directory of Open Access Journals (Sweden)

Smarzyńska Karolina

2016-06-01

Full Text Available Soil and Water Assessment Tool (SWAT ver. 2005 was applied to study water balance and nitrogen load pathways in a small agricultural watershed in the lowlands of central Poland. The natural flow regime of the Zgłowiączka River was strongly modified by human activity (deforestation and installation of a subsurface drainage system to facilitate stable crop production. SWAT was calibrated for daily and monthly discharge and monthly nitrate nitrogen load. Model efficiency was tested using manual techniques (subjective and evaluation statistics (objective. Values of Nash–Sutcliffe efficiency coefficient (NSE, coefficient of determination (R2 and percentage of bias for daily/monthly discharge simulations and monthly load indicated good or very good fit of simulated discharge and nitrate nitrogen load to the observed data set. Model precision and accuracy of fit was proved in validation. The calibrated and validated SWAT was used to assess water balance and nitrogen fluxes in the watershed. According to the results, the share of tile drainage in water yield is equal to 78%. The model analysis indicated the most significant pathway of NO3-N to surface waters in the study area, namely the tile drainage combined with lateral flow. Its share in total NO3-N load amounted to 89%. Identification of nitrogen fluxes in the watershed is crucial for decision makers in order to manage water resources and to implement the most effective measures to limit diffuse pollution from arable land to surface waters.

DIAGNOSIS OF FINANCIAL POSITION BY BALANCE SHEET ANALYSIS - CASE STUDY

OpenAIRE

Hada Teodor; Marginean Radu

2013-01-01

This study aims to elucidate and to exemplify an important technique for assessing the economic entities, namely the fundamental analysis of the balance sheet, in several significant aspects. The analysis of financial data reported in the balance sheet are, for an economic entity, the basis of a principle diagnosis by determining specific indicators of economic and financial analysis. This analysis aims to provide an insight into the companyâ€(tm)s financial position. The stated aim of this s...

Evolutions and Trends in Presenting. The Balance Sheet as a Financial Position Picture of an Entity

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Ecaterina Necsulescu

2011-08-01

Full Text Available In this article we proposed to achieve a synthesis of the key moments in the evolution of the concept of balance, of the theories formulated over time, of the presentation forms of the balance sheet, a taxonomy of balance sheets, supplemented by a breakdown of the concept of financial position and of the structures related to the assessment of the financial position. In other words, we will consider a gradual presentation of the concept of balance sheet over time and a presentation of the balance as the main tool for highlighting the patrimonial situation, of the assets of enterprise owners and of the picture on the financial position of an economic entity.

Stability improvement for coil position locking of joule balance

Science.gov (United States)

Bai, Yang; Liu, Yongmeng; Lu, Yunfeng; Hu, Pengcheng; Wang, Dawei; Li, Zhengkun; Tan, Jiubin; Zhang, Zhonghua

2017-08-01

The relative vertical position locking precision between the exciting and suspended coils is an important uncertainty for the Planck constant traceability in joule balance. In order to improve the relative vertical position locking precision, several stability experiments are conducted. The stability characteristics of the suspended and exciting coils are measured using a six-axis laser interferometer system; meanwhile, the effectiveness of the active vibration isolation table is measured using a vibration measurement sensor. The piezoelectric ceramic actuators with PID controller are used to compensate the relative vertical displacement drifts while a six-axis laser interferometer system is used to measure the positions of two coils. Experimental results show that the relative vertical position is stably locked.

Soil nitrogen balance assessment and its application for sustainable agriculture and environment

Institute of Scientific and Technical Information of China (English)

Rabindra; Nath; Roy

2005-01-01

[1]United Nations,World Population Prospects:The 1998 Revision,New York,1999.[2]FAO,Fertilizer Requirements in 2015 and 2030,Rome:FAO,2000.[3]IPCC,Climate Change 1995:The Science of Climate Change,Cambridge:Cambridge University Press,1996.[4]USEPA Impact Assessment Report US EPA,Office of Policy,Planning and Evaluation,Washington,DC,1997.[5]IFA/FAO,Global estimates of gaseous emissions of NH3,NO and N2O from agricultural land,Rome,2001.[6]Stoorvogel,J.J.,Smaling,E.M.A.,Assessment of Soil Nutrient Depletion in Sub-Saharan Africa:1983-2000.Report 28,Wageningen:Winland Staring Centre,1990.[7]Pieri,C.,Bilans minéraux des systèmes de cultures pluviales en zones arides et semi-arides,L'Agron.Trop.,1985,40:1 -20.[8]Henao,J.,Baanante,C.,Estimating Rates of Nutrient Depletion in Soils of Agriculture Lands in Africa,Muscle Shoals:International Fertilizer Development Center,1999.[9]OECD,OECD National Soil Surface Nitrogen Balances-Explanatory Notes,Paris:OECD Secretariat,200la.[10]OECD,Environmental Indicators for Agriculture,Volume 3:Methods and Results,Paris:OECD Secretariat,200lb.[11]Sheldrick,W.F.,Syers,J.K.,Lingard,J.,A conceptual model for conducting nutrient audits at national,regional,and global scales,Nut.Cyc.Agroecosys.,2002,62:61-72.[12]Sheldrick,W.F,Syers,J.K.,Lingard,J.,Soil nutrient audits for China to estimate nutrient balances and output/input relationships,Ag.Ecosys.Env.,2003a,94:341-354.[13]FAO,Scaling soil nutrient balances-enabling mesolevel applications for African realities,in Fertilizer and Plant Nutrition Bull.15,Rome:FAO,2004.[14]IFA/IFDC/FAO,Fertilizer Use by Crop,4th ed.,Rome:IFA/IFDC/FAO,2000.[15]De Willigen,P.,An analysis of the calculation of leaching and denitrification losses as practised in the NUTMON approach.Report 18,Wageningen:Plant Research International,2000.[16]Schoorl,J.M.,Veldkamp,A.,Bouma,J.,Modelling water and soil redistribution in a dynamic landscape context,Soil Sci.Soc.Am.,2002,66:1610- 1619.[17]Smaling

Metabolizable energy, nitrogen balance, and ileal digestibility of amino acids in quality protein maize for pigs

Science.gov (United States)

2014-01-01

Background To compare the nutritional value and digestibility of five quality protein maize (QPM) hybrids to that of white and yellow maize, two experiments were carried out in growing pigs. In experiment 1, the energy metabolizability and the nitrogen balance of growing pigs fed one of five QPM hybrid diets were compared against those of pigs fed white or yellow maize. In experiment 2, the apparent and standardized ileal digestibility (AID and SID, respectively) of proteins and amino acids from the five QPM hybrids were compared against those obtained from pigs fed white and yellow maize. In both experiments, the comparisons were conducted using contrasts. Results The dry matter and nitrogen intakes were higher in the pigs fed the QPM hybrids (P digestibility (P digestible lysine than normal maize. PMID:25045520

Nitrogen balance and milk composition of dairy cows fed urea and soybean meal and two protein levels using sugar cane based diets

OpenAIRE

Luís Henrique Andreucci Conti; Elmeson Ferreira de Jesus; Angélica Simone Cravo Pereira; Marcos André Arcari; Kleber da Cunha Peixoto Junior; Francisco Palma Rennó; Marcos Veiga dos Santos

2014-01-01

The aim of the study was to evaluate the effect of feeding two levels of crude protein (CP) (low: 142 g CP/kg DM; and high: 156 g CP/kg DM) and two nitrogen sources (soybean meal and urea) to dairy cows using sugar cane as forage on microbial protein synthesis, the composition of the milk nitrogen fraction, nitrogen (N) balance and blood parameters. Twelve Holstein cows with an average milk yield of 22.0 ± 2.3 kg/day, and with 235 ± 40 days in milk were included in this study. The animals wer...

Influence of Hippotherapy on Body Balance in the Sitting Position Among Children with Cerebral Palsy.

Science.gov (United States)

Matusiak-Wieczorek, Ewelina; Małachowska-Sobieska, Monika; Synder, Marek

2016-03-23

Cerebrally palsied children demonstrated limited independence while performing various activities of daily living, which is due to disorders of postural control. The best solution to improve postural control is the use of therapies that simultaneously focus on the sense of balance and motor skills. Such possibilities for patients with cerebral palsy are offered, for example, by hippotherapy. To assess the influence of hippotherapy on body balance in the sitting position among children with cerebral palsy. The study enrolled thirty-nine children aged 6-12 years with GMFCS level 1 or 2 spastic diplegia or spastic hemiplegia. The participants were divided into an intervention group (n=19) and a control group (n=20). Children from the intervention group attended 30 minutes of hippotherapy once weekly for 12 consecutive weeks. The Sitting Assessment Scale (SAS) was used to assess the patients' posture and balance. Some children improved their posture and balance during the study. Generally, control of trunk and head position and function of arms were getting better, while footwork was the weakest. Hippotherapy has positive effects on the position and function of individual parts of the body, thus making it possible for cerebrally palsied children to improve posture and the ability to maintain balance in the sitting position.

Digestibility and nitrogen balance of lambs fed sugarcane hydrolyzed under different conditions as roughage in the diet

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Viviane Endo

2015-02-01

Full Text Available This study aimed to evaluate the digestibility and nitrogen balance (NB of lambs fed sugarcane hydrolyzed under different conditions. Fifteen Ile de France lambs at, on average, 23.5kg of body weight were evaluated. Treatments were: in natura sugarcane (IN, sugarcane hydrolyzed using 0.6% calcium oxide (CaO under aerobic condition (AER, and sugarcane hydrolyzed using 0.6% CaO under anaerobic condition (ANA. Therefore, a completely randomized design was constituted with five replicates per treatment. Treatments were supplied to animals along with concentrate. Both hydrolysis conditions aimed to alter the sugarcane fermentation pattern, therefore improving fiber digestibility. Lambs were housed in individual pens and fed with diet allowing 10% of refusals. Refusals, feces and urine were sampled daily during five days. They were collected to determine the digestibility and NB. A higher digestibility of neutral detergent fiber corrected for ash and protein (57.05%, organic matter (85.39%, hemicellulose (72.09%, NB (29.46g day-1 and 2.78g kg-0.75 day-1 and rate of nitrogen absorbed (3.00g kg-0.75 day-1 were observed for lambs fed with ANA than for those fed IN (41.17%, 73.76%, 53.80%, 21.39g day-1, 2.00g kg-0.75 day-1 and 2.22g kg-0.75 day-1, respectively. As roughage, ANA in the lamb diet, optimizes the nitrogen balance and is more efficient to improve the digestibility of some nutrients compared to IN. Whereas AER was as efficient as ANA and IN

Intake, digestibility, and nitrogen balance of rations containing different levels of murumuru meal in sheep diets

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Bruno Peres de Menezes

2016-02-01

Full Text Available This study aimed to assess the potential use of increasing levels of murumuru cake Astrocaryum murumuru var. murumuru, M art. (MC in sheep diets as a replacement for Mombasa grass (Panicum maximum Jacq. Metabolic tests were performed with 20 castrated male sheep at Embrapa Amazônia Oriental, Belém, Pará, during 26 days. The experiment was arranged in a completely randomized design, with five diets and four replications. MC0: 100% grass; MC10: 10% MC and 90% grass; MC20: 20% MC and 80% grass; MC40: 40% MC and 60% grass; and MC60: 60% MC and 40% grass. The intake and the coefficient of apparent digestibility of dry matter (DMI and CDDM, organic matter (OMI and CDOM, crude protein (CPI and CDCP, neutral detergent fiber (NDFI and CDNDF, acid detergent fiber (ADFI and CDADF, ether extract (EEI and CDEE, cellulose (CELI and CDCEL, hemicellulose (HEMI and CDHEM, and nitrogen balance (NB of experimental diets were determined. The intake of mineral material (MMI and lignin (LIGI were also determined. The DMI, OMI, MMI, CPI, NDFI, and ADFI displayed a decreasing linear effect with the replacement of Mombasa grass by MC in the diet. The EEI and the LIGI presented quadratic effects according to the replacement levels of MC in the diet. The CDDM, CDOM, and CDHEM displayed increasing linear effects, between MC0 and MC60. The CDEE, CDNDF, CDADF, and CDCEL displayed a quadratic effect, with optimum replacement levels of 56.65%, 41%, 31.33%, and 27.46%, respectively. The nitrogen balance presented a negative linear effect in the range of 0% to 60% of murumuru cake. One can conclude that murumuru cake is an alternative to the dietary supplementation of ruminants in replacing the Mombasa grass because it provides an increase in the digestibility of nutrients for sheep. However, a limited replacement level must be implemented, considering that from 27.46%, 31.33%, 41%, and 56.65% replacement, a decline occurs in the CDCEL, CDADF, CDNDF, and CDEE, respectively

Farm nitrogen balances in six European landscapes as an indicator for nitrogen losses and basis for improved management

DEFF Research Database (Denmark)

Dalgaard, Tommy; Bienkowski, J F; Bleeker, A

2012-01-01

Improved management of nitrogen (N) in agriculture is necessary to achieve a sustainable balance between the production of food and other biomass, and the unwanted effects of N on water pollution, greenhouse gas emissions, biodiversity deterioration and human health. To analyse farm N...... was found with N measured in surface waters, probably because of spatial and temporal variations in groundwater buffering and biogeochemical reactions affecting N flows from farm to surface waters. A case study of the development in N surplus from the landscape in DK from 1998–2008 showed a 22% reduction......-losses and the complex interactions within farming systems, efficient methods for identifying emissions hotspots and evaluating mitigation measures are therefore needed. The present paper aims to fill this gap at the farm and landscape scales. Six agricultural landscapes in Poland (PL), the Netherlands (NL), France (FR...

Nitrogen mass balance in the Brazilian Amazon: an update.

Science.gov (United States)

Martinelli, L A; Pinto, A S; Nardoto, G B; Ometto, J P H B; Filoso, S; Coletta, L D; Ravagnani, E C

2012-08-01

The main purpose of this study is to perform a nitrogen budget survey for the entire Brazilian Amazon region. The main inputs of nitrogen to the region are biological nitrogen fixation occurring in tropical forests (7.7 Tg.yr(-1)), and biological nitrogen fixation in agricultural lands mainly due to the cultivation of a large area with soybean, which is an important nitrogen-fixing crop (1.68 Tg.yr(-1)). The input due to the use of N fertilizers (0.48 Tg.yr(-1)) is still incipient compared to the other two inputs mentioned above. The major output flux is the riverine flux, equal to 2.80 Tg.yr(-1) and export related to foodstuff, mainly the transport of soybean and beef to other parts of the country. The continuous population growth and high rate of urbanization may pose new threats to the nitrogen cycle of the region through the burning of fossil fuel and dumping of raw domestic sewage in rivers and streams of the region.

15N dilution technique of assessing the contribution of nitrogen fixation to rice plant

International Nuclear Information System (INIS)

Ventura, Wilbur; Watanabe, Iwao

1983-01-01

An attempt to correlate the positive nitrogen balance in rice-soil system with the 15 N dilution in rice plants was made to see if isotope dilution can be used to assess the contribution of nitrogen fixation to the nitrogen nutrition of rice. 15 N ammonium sulfate and sucrose were added to the moist soil in pots to label biomass nitrogen fraction. The rice-soil system with higher nitrogen gain had lower 15 N content in the rice plants. When the surface of pots was covered with black cloths to suppress photodependent N 2 fixation, no significant nitrogen gain was observed. Significant gain was found in the rice-flooded soil system exposed to light, and the 15 N content of plants decreased in allowing the photodependent N 2 fixation by blue-green algae symbiosis. The contribution of plant nitrogen derived from photodependent N 2 fixation was estimated to be 20-30 % of the positive nitrogen gain in the system by the 15 N dilution technique using the rice-covered soil as reference system. (Mori, K.)

Efficiency of open-hearth slag under different levels of nitrogen nutrition

Energy Technology Data Exchange (ETDEWEB)

Merzlyakov, L A

1979-01-01

Field and vegetational experiments have been carried out in the turf-podsolic soil in 1974-1977. Efficiency of open-hearth slag from the Izhevsk metallurgical plant depends on the level of nitrogen nutrition. The greatest addition from the slag is received at the elevated level of nitrogen nutrition. The maximum total addition for 3 years resulting from the use of slag in the field experiment constituted 54.5 double centner forage units which is higher than the addition resulting from lime by 52.7 %. Besides, the slag produced a positive effect upon the balance of the labelled /sup 15/N nitrogen in fertilizer: coefficient of the use of nitrogen in fertilizer during 2 years in the average increased by 7.1 and 11.2 % according to the nitrogen background of 230 and 460 mg/vessel.

Efficiency of open-hearth slag under different levels of nitrogen nutrition

International Nuclear Information System (INIS)

Merzlyakov, L.A.

1979-01-01

Field and vegetational experiments have been carried out in the turf-podsolic soil in 1974-1977. Efficiency of open-hearth slag from Izhevsk metallurgical plant depends on the level of nitrogen nutrition. The greatest addition from the slag is received at the elevated level of nitrogen nutrition. The maximum total addition for 3 years resulting from the use of slag in the field experiment constituted 54.5 double centner forage units which is higher than the addition resulting from lime by 52.7 %. Besides, the slag produced positive effect upon the balance of the labelled 15 N nitrogen in fertilizer: coefficient of the use of nitrogen in fertilizer during 2 years in the average increased by 7.1 and 11.2 % according to the nitrogen background of 230 and 460 mg/vessel

Using Water and Agrochemicals in the Soil, Crop and Vadose Environment (WAVE Model to Interpret Nitrogen Balance and Soil Water Reserve Under Different Tillage Managements

Directory of Open Access Journals (Sweden)

Zare Narjes

2014-10-01

Full Text Available Applying models to interpret soil, water and plant relationships under different conditions enable us to study different management scenarios and then to determine the optimum option. The aim of this study was using Water and Agrochemicals in the soil, crop and Vadose Environment (WAVE model to predict water content, nitrogen balance and its components over a corn crop season under both conventional tillage (CT and direct seeding into mulch (DSM. In this study a corn crop was cultivated at the Irstea experimental station in Montpellier, France under both CT and DSM. Model input data were weather data, nitrogen content in both the soil and mulch at the beginning of the season, the amounts and the dates of irrigation and nitrogen application. The results show an appropriate agreement between measured and model simulations (nRMSE < 10%. Using model outputs, nitrogen balance and its components were compared with measured data in both systems. The amount of N leaching in validation period were 10 and 8 kgha–1 in CT and DSM plots, respectively; therefore, these results showed better performance of DSM in comparison with CT. Simulated nitrogen leaching from CT and DSM can help us to assess groundwater pollution risk caused by these two systems.

Effect of prolonged intravenous glucose and essential amino acid infusion on nitrogen balance, muscle protein degradation and ubiquitin-conjugating enzyme gene expression in calves

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Scaife Jes R

2008-02-01

Full Text Available Abstract Background Intravenous infusions of glucose and amino acids increase both nitrogen balance and muscle accretion. We hypothesised that co-infusion of glucose (to stimulate insulin and essential amino acids (EAA would act additively to improve nitrogen balance by decreasing muscle protein degradation in association with alterations in muscle expression of components of the ubiquitin-proteasome proteolytic pathway. Methods We examined the effect of a 5 day intravenous infusions of saline, glucose, EAA and glucose + EAA, on urinary nitrogen excretion and muscle protein degradation. We carried out the study in 6 restrained calves since ruminants offer the advantage that muscle protein degradation can be assessed by excretion of 3 methyl-histidine and multiple muscle biopsies can be taken from the same animal. On the final day of infusion blood samples were taken for hormone and metabolite measurement and muscle biopsies for expression of ubiquitin, the 14-kDa E2 ubiquitin conjugating enzyme, and proteasome sub-units C2 and C8. Results On day 5 of glucose infusion, plasma glucose, insulin and IGF-1 concentrations were increased while urea nitrogen excretion and myofibrillar protein degradation was decreased. Co-infusion of glucose + EAA prevented the loss of urinary nitrogen observed with EAA infusions alone and enhanced the increase in plasma IGF-1 concentration but there was no synergistic effect of glucose + EAA on the decrease in myofibrillar protein degradation. Muscle mRNA expression of the ubiquitin conjugating enzyme, 14-kDa E2 and proteasome sub-unit C2 were significantly decreased, after glucose but not amino acid infusions, and there was no further response to the combined infusions of glucose + EAA. Conclusion Prolonged glucose infusion decreases myofibrillar protein degradation, prevents the excretion of infused EAA, and acts additively with EAA to increase plasma IGF-1 and improve net nitrogen balance. There was no evidence of

Evaluation of phosphorus and nitrogen balances as an indicator for the impact of agriculture on environment a comparison of case studies from Poland and the Mississippi US

Science.gov (United States)

The objective of the research was to quantify the changes of nitrogen (N) and phosphorus (P) balances in Poland and Mississippi (MS). Nutrient balances were calculated as difference between input and output in the agricultural system according to Organisation for Economic Cooperation and Development...

Nitrogen emission balance for Niedersachsen; Bilanzierung der Stickstoffemissionen in Niedersachsen

Energy Technology Data Exchange (ETDEWEB)

Krieg, V.

2000-07-01

This report provides a comprehensive emission balance for the German state of Niedersachsen, which will provide a basis for deciding on actions to reduce nitrogen levels. [German] In einem natuerlichen Oekosystem erfolgt der Grossteil des Stickstoffumsatzes als Kreisprozess, aus dem nur verhaeltnismaessig geringe Mengen in das System importiert bzw. aus dem System exportiert werden. Durch menschliche Nutzungsaktivitaeten wie insbesondere im landwirtschaftlichen Bereich sowie durch atmosphaerische Eintraege wird dieser natuerliche Kreislauf stark beeintraechtigt. In der Regel kann in den dicht besiedelten industriell gepraegten und landwirtschaftlich intensiv genutzten Regionen Europas von einem deutlichen Stickstoffueberschuss ausgegangen werden mit den negativen Folgen von Boden- und Gewaesserbelastung und den Eutrophierungserscheinungen bei aquatischen und terrestrischen Oekosystemen. Der dringende Handlungsbedarf zur Senkung der menschlich verursachten Stickstoffueberschuesse ist offensichtlich und in einem Bericht der Arbeitsgruppe aus Vertretern der Umwelt- und Agrarministerkonferenz (STICKSTOFFMINDERUNGSPROGRAMM, 1997) dokumentiert. Grundlage fuer entsprechende Massnahmen muss der Nachweis der entsprechenden Emissionsquellen unter Beruecksichtigung von wechselseitigen Beeinflussungen sein. Der vorliegende Bericht liefert fuer das Bundesland Niedersachsen eine vollstaendige Bilanzierung und damit eine fundierte Basis fuer entsprechende Handlungsempfehlungen zur Reduzierung des Stickstoffniveaus. (orig.)

Modelling the carbon and nitrogen balances of direct land use changes from energy crops in Denmark

DEFF Research Database (Denmark)

Hamelin, Lorie; Jørgensen, Uffe; Petersen, Bjørn Molt

2012-01-01

This paper addresses the conversion of Danish agricultural land from food/feed crops to energy crops. To this end, a life cycle inventory, which relates the input and output flows from and to the environment of 528 different crop systems, is built and described. This includes seven crops (annuals...... and perennials), two soil types (sandy loam and sand), two climate types (wet and dry), three initial soil carbon level (high, average, low), two time horizons for soil carbon changes (20 and 100 years), two residues management practices (removal and incorporation into soil) as well as three soil carbon turnover...... rate reductions in response to the absence of tillage for some perennial crops (0%, 25%, 50%). For all crop systems, nutrient balances, balances between above- and below-ground residues, soil carbon changes, biogenic carbon dioxide flows, emissions of nitrogen compounds and losses of macro...

Effects of additive application upon ad libitum intake, in vivo digestibility and nitrogen balance of alfalfa haylage

Directory of Open Access Journals (Sweden)

Mladen Knežević

2009-09-01

Full Text Available The research objective was to determine the effect of the additive Sill-All application on ad libitum intake, in vivo digestibility and nitrogen balance of alfalfa haylage. About 40 % alfalfa plants was ensiled at the phonological flowering stage into plastic foil-wrapped bales without or with additive (2 L t-1 plant mass. No statistically significant differences were found between alfalfa ensiled without additive and alfalfa ensiled with additive for the content of dry matter (DM (632 g and 631 g DM kg-1 fresh sample, respectively. Alfalfa ensiled without additive contained 921 g organic matter (OM kg-1 DM, which was significantly higher (P<0.001 compared to alfalfa ensiled with additive (902 g OM kg-1 DM. Alfalfa ensiled without additive contained 141 g crude proteins (CP kg-1 DM, which was significantly higher (P<0.001 compared to alfalfa ensiled with additive (139 g CP kg-1 DM. Alfalfa ensiled with additive contained significantly less acid detergent fibers (ADF (P<0.001 compared to alfalfa ensiled without additive (445 g kg-1 DM and 456 g kg-1 DM, respectively and had a lower pH value (P<0.001 (5.29 and 5.56, respectively. No statistically significant differences were found between the studied feeding treatments for ad libitum intake of fresh ration and DM ration, for the measured parameters of digestibility and N balance. It was concluded that addition of the additive to alfalfa haylage led to significant changes in chemical composition; however, changes in chemical composition had no impact on measured biological parameters (ad libitum intake, in vivo digestibility and nitrogen balance.

/sup 15/N dilution technique of assessing the contribution of nitrogen fixation to rice plant

Energy Technology Data Exchange (ETDEWEB)

Ventura, W; Watanabe, Iwao [International Rice Research Inst., College, Laguna (Phillippines)

1983-06-01

An attempt to correlate the positive nitrogen balance in rice-soil system with the /sup 15/N dilution in rice plants was made to see if isotope dilution can be used to assess the contribution of nitrogen fixation to the nitrogen nutrition of rice. /sup 15/N ammonium sulfate and sucrose were added to the moist soil in pots to label biomass nitrogen fraction. The rice-soil system with higher nitrogen gain had lower /sup 15/N content in the rice plants. When the surface of pots was covered with black cloths to suppress photodependent N/sub 2/ fixation, no significant nitrogen gain was observed. Significant gain was found in the rice-flooded soil system exposed to light, and the /sup 15/N content of plants decreased in allowing the photodependent N/sub 2/ fixation by blue-green algae symbiosis. The contribution of plant nitrogen derived from photodependent N/sub 2/ fixation was estimated to be 20-30 % of the positive nitrogen gain in the system by the /sup 15/N dilution technique using the rice-covered soil as reference system.

Challenges of work-life balance for women physicians/mothers working in leadership positions.

Science.gov (United States)

Schueller-Weidekamm, Claudia; Kautzky-Willer, Alexandra

2012-08-01

Female leadership in medicine is still disproportionately small, which might be due to the barriers of combining work and family. The aim of this study was, first, to perform a strengths, weakness, opportunities, and threats (SWOT) analysis and, second, to create a strategic concept for career development. In this study, all women in leadership positions in the health care system in Vienna, Austria, with at least 1 child (n = 8), were interviewed about the advantages and disadvantages of gender with regard to career development, the strengths and weaknesses of female leadership, and their work-life balance. Different factors that influenced the work-life balance were specified, and career strategies to realize adequate solutions were developed. The sporadic focus on career advancement, time-consuming child care, responsibility for family life, and a woman's tendency toward understatement were barriers to career development. Work-family enrichment has a positive spillover effect that spreads positive energy and helps to balance the work-life relationship. For each individual, the allocation and interaction of different resources such as time, money, scope of decision making, and physical, emotional, and social resources, were essential to maintain the individual work-life balance. In addition to the existing "glass ceiling," the predominant responsibility for child care is still borne by the woman. However, mentoring programs, coaching, networking, and support of the partner or of other people help to strengthen female "soft" skills and achieve a work-life balance. Copyright © 2012 Elsevier HS Journals, Inc. All rights reserved.

Effects of feed loading on nitrogen balances and fish performance in replicated recirculating aquaculture systems

DEFF Research Database (Denmark)

Pedersen, Lars-Flemming; Suhr, Karin Isabel; Dalsgaard, Anne Johanne Tang

2012-01-01

This study investigated the effects of applying four fixed feed loadings to three replicated recirculating aquaculture systems (RAS) on water quality changes, nitrogenous balances and growth performance of rainbow trout (Oncorhynchus mykiss).Feed loadings ranged from 1.6 to 6.3kgfeed/m3 make-up...... water, with a constant make-up water renewal of 4.7% of total water volume per day in all twelve RAS. Fish densities ranged from 14 to 92kg/m3 during the prolonged trial of 10weeks. Selected water quality parameters were measured during two intensive sampling campaigns, evaluating biofilter...

Full protein alimentation and nitrogen equilibrium in a renal failure patient treated with continuous hemodiafiltration: a case report of 67 days of continuous hemodiafiltration.

Science.gov (United States)

Reynolds, H N; Borg, U; Frankenfield, D

1992-01-01

Standard care for patients with renal failure while in an intensive care unit involves traditional hemodialysis or peritoneal dialysis and protein restriction. We present a case of a patient with renal failure supported with continuous arteriovenous hemofiltration with dialysis (CAVH-D) who was given full protein alimentation. Total daily urea clearance was measured from the CAVH-D output. Protein load was 196 +/- 34 g/day while receiving total parenteral nutrition and 164 +/- 30 g/day while receiving enteral alimentation. Serum blood urea nitrogen was controlled between 40 and 75 mg/dL, except during septic episodes. Nitrogen balance was estimated based upon known alimentation protein load and measurable and estimated nitrogenous losses. The patient was potentially in nitrogen equilibrium during most of the dialysis period. The cumulative nitrogen balance was positive by 5.2 g after 67 days of dialysis. Volume of alimentation was 3.49 +/- 0.7 liters/day. With CAVH-D, the renal failure patient can receive full alimentation without volume or protein load limitations. Furthermore, nitrogen balances can be estimated easily while the patient is on CAVH-D.

Nitrogen and carbon source balance determines longevity, independently of fermentative or respiratory metabolism in the yeast Saccharomyces cerevisiae.

Science.gov (United States)

Santos, Júlia; Leitão-Correia, Fernanda; Sousa, Maria João; Leão, Cecília

2016-04-26

Dietary regimens have proven to delay aging and age-associated diseases in several eukaryotic model organisms but the input of nutritional balance to longevity regulation is still poorly understood. Here, we present data on the role of single carbon and nitrogen sources and their interplay in yeast longevity. Data demonstrate that ammonium, a rich nitrogen source, decreases chronological life span (CLS) of the prototrophic Saccharomyces cerevisiae strain PYCC 4072 in a concentration-dependent manner and, accordingly, that CLS can be extended through ammonium restriction, even in conditions of initial glucose abundance. We further show that CLS extension depends on initial ammonium and glucose concentrations in the growth medium, as long as other nutrients are not limiting. Glutamine, another rich nitrogen source, induced CLS shortening similarly to ammonium, but this effect was not observed with the poor nitrogen source urea. Ammonium decreased yeast CLS independently of the metabolic process activated during aging, either respiration or fermentation, and induced replication stress inhibiting a proper cell cycle arrest in G0/G1 phase. The present results shade new light on the nutritional equilibrium as a key factor on cell longevity and may contribute for the definition of interventions to promote life span and healthy aging.

15N nitrogen-balance studies in patients with testicular feminization, their relatives, and in normal subjects

International Nuclear Information System (INIS)

Zachman, M.; Zagalak, M.; Voellmin, J.A.; Prader, A.

1975-01-01

Fourteen subjects (4 with testicular feminization, 2 mothers, 1 aunt and 1 father of these patients, 2 normal women, 2 normal men and 2 normal prepubertal boys) were given 0.1 to 0.2 g/kg of 50 percent 15 N-labeled NH 4 Cl before and after 6 daily injections of testosterone (T) 15 mg/m 2 ). In 24-hour urine specimens collected on the test days, 15 N was calculated from total N (Kjeldahl) and the percentage of 15 N (mass spectrometry or 15 N-analyzer Isocommerz). In all normal subjects, urinary 15 N-balance was influenced positively by T (+31.3 +- 8.4 percent), in prepubertal boys more (+43 to +66 percent) than in women (+20 to +30 percent) and men (+6 to +23). In testicular feminization, 15 N-balance not only failed to become more positive, but was even reduced (-24.7 +- 17.6 percent). The father of a patient had only a slight response (+7 percent) as one of the normal males, probably because of higher endogenous T-levels in adult males. One mother and the aunt had no response (-7.4 to + 1.5 percent). In the mother, the balance became slightly positive (+10 percent) on oral contraceptives. The other mother, who was on estrogen treatment prior to and during the test, had a positive but insufficient change of balance (+17 percent). It is concluded that this test allows detection of patients with testicular feminization and possibly also healthy female carriers. In these cases, estrogen treatment appears to positively influence the response to T

Nitrogen retention and water balance in animals fed medium protein ...

African Journals Online (AJOL)

amount of nitrogen, in contrast to control animals that lost 2.4% nitrogen via the faeces. Inadequate drinking caused decreased excretion of urea. The improved nitrogen retention coupled with high rates of urea recycling enhances nutrients digestion and consequently the animals' absorptive capabilities. . (Afr. J. Biomed.

How Positivity Links With Job Satisfaction: Preliminary Findings on the Mediating Role of Work-Life Balance.

Science.gov (United States)

Orkibi, Hod; Brandt, Yaron Ilan

2015-08-01

The positive characteristics that can help people juggle their work and personal roles and experience greater job satisfaction are attracting increased research attention. This study presents a conceptual model to account for the association between employees' positive orientation (i.e., the tendency to evaluate self, life, and the future in a positive way) and their job satisfaction (N = 108). As theorized, the results indicate that employees' ability to manage their work-life balance fully mediates the relation between their positive orientation and job satisfaction. This suggests that a positive orientation serves as an adaptive personal resource that can facilitate employees' ability to balance work and non-work demands and hence can foster job satisfaction. The practical implications for positive psychological interventions in organizational settings are discussed.

Simulation of nitrogen balance of maize field under different drainage strategies using the DRAINMOD-N model

International Nuclear Information System (INIS)

El-Sadek, A.; Feyen, J.; Ragab, R.

2002-01-01

'Full text:' Denitrification is the process by which nitrate-nitrogen is converted to nitrogen gas by soil microorganisms when soil oxygen is low or absent. The process of denitrification is important in preventing high agriculture-source nitrate loads from entering and polluting rivers. The aim of the research was to examine if the NO3-N concentration in drain water of agricultural fields can be kept below the EU limit of 11.3 mg l -1 by controlling the denitrification process through management of the water table level. As such the research focused on the determination of the exact denitrification amount to achieve both, limitation of the NO3-N leaching and optimisation of the nitrogen-nitrate uptake by the crop. The method used in this study is based on the nitrogen version of DRAINMOD model. This model was used to simulate the performance of the drainage system using two drainage strategies (conventional and controlled) at the Hooibeekhoeve experiment, situated in the sandy region of the Kempen (Belgium), and this for a 14-year (1985-1998) period. In the analysis a continuous cropping with maize was assumed. Daily NO3-N losses were predicted for a range of drain spacings. The study illustrated that the denitrification process has a very strong impact on the amount of nitrate that can be leached to ground and surface waters. The results have also shown that if the water table elevation is properly controlled, one should be able to strike the delicate balance between our need for maximum yield production and a minimum hazard to our environment. (author)

Nitrogen Exchanges: Testing the Hypothesis of a Country without Agricultural Production

Directory of Open Access Journals (Sweden)

M.-F. Slak

2001-01-01

Full Text Available Today, finding data on agricultural nitrogen balances is quite easy. Calculations of such balances are carried out by most of the European countries as an indicator of environmental pollution attributable to the agricultural sector. In France, average values of agricultural nitrogen balances show an excess of 1.5 to 2 million tons of nitrogen. This excess is enormous. What would the balance of a country be if agricultural activity were stopped? In the following article, a country (France is used as an example without agriculture is studied in order to assess its nitrogen balance. Using a previously published model describing nitrogen input and output of a given country, nitrogen flows are identified. Inputs include deposition, fixation, and products not intended for agricultural use. Outputs are reduced to zero if agriculture disappears (in France, agriculture is the only sector exporting products containing nitrogen. All flows are calculated considering the hypothesis of disappearance of agriculture. Nitrogen requirements to feed people and pets in France are estimated based on medical and veterinary data (recommended daily amounts for proteins and/or usual average consumption. Indeed, most of the food that nourishes the French population is produced nationally. If agriculture stops, it will be necessary to import food from foreign countries. Results show an unexpectedly high excess (for a country without agriculture having a structure similar to France: number of human beings and pets of 1.5 million tons of nitrogen. An attempt to calculate an agricultural balance with the same data gives a result close to 3 million tons. Differences in French agricultural balances found in the literature can mainly be explained by values taken into account for deposition and fixation (values used here are at least 300,000 tons higher than values used by the Organisation for Economic Co-operation and Development. In conclusion, nitrogen excess in agriculture

How Positivity Links With Job Satisfaction: Preliminary Findings on the Mediating Role of Work-Life Balance

Science.gov (United States)

Orkibi, Hod; Brandt, Yaron Ilan

2015-01-01

The positive characteristics that can help people juggle their work and personal roles and experience greater job satisfaction are attracting increased research attention. This study presents a conceptual model to account for the association between employees’ positive orientation (i.e., the tendency to evaluate self, life, and the future in a positive way) and their job satisfaction (N = 108). As theorized, the results indicate that employees’ ability to manage their work-life balance fully mediates the relation between their positive orientation and job satisfaction. This suggests that a positive orientation serves as an adaptive personal resource that can facilitate employees’ ability to balance work and non-work demands and hence can foster job satisfaction. The practical implications for positive psychological interventions in organizational settings are discussed. PMID:27247666

How Positivity Links With Job Satisfaction: Preliminary Findings on the Mediating Role of Work-Life Balance

Directory of Open Access Journals (Sweden)

Hod Orkibi

2015-08-01

Full Text Available The positive characteristics that can help people juggle their work and personal roles and experience greater job satisfaction are attracting increased research attention. This study presents a conceptual model to account for the association between employees’ positive orientation (i.e., the tendency to evaluate self, life, and the future in a positive way and their job satisfaction (N = 108. As theorized, the results indicate that employees’ ability to manage their work-life balance fully mediates the relation between their positive orientation and job satisfaction. This suggests that a positive orientation serves as an adaptive personal resource that can facilitate employees’ ability to balance work and non-work demands and hence can foster job satisfaction. The practical implications for positive psychological interventions in organizational settings are discussed.

Mineral nitrogen sources differently affect root glutamine synthetase isoforms and amino acid balance among organs in maize.

Science.gov (United States)

Prinsi, Bhakti; Espen, Luca

2015-04-03

Glutamine synthetase (GS) catalyzes the first step of nitrogen assimilation in plant cell. The main GS are classified as cytosolic GS1 and plastidial GS2, of which the functionality is variable according to the nitrogen sources, organs and developmental stages. In maize (Zea mays L.) one gene for GS2 and five genes for GS1 subunits are known, but their roles in root metabolism are not yet well defined. In this work, proteomic and biochemical approaches have been used to study root GS enzymes and nitrogen assimilation in maize plants re-supplied with nitrate, ammonium or both. The plant metabolic status highlighted the relevance of root system in maize nitrogen assimilation during both nitrate and ammonium nutrition. The analysis of root proteomes allowed a study to be made of the accumulation and phosphorylation of six GS proteins. Three forms of GS2 were identified, among which only the phosphorylated one showed an accumulation trend consistent with plastidial GS activity. Nitrogen availabilities enabled increments in root total GS synthetase activity, associated with different GS1 isoforms according to the nitrogen sources. Nitrate nutrition induced the specific accumulation of GS1-5 while ammonium led to up-accumulation of both GS1-1 and GS1-5, highlighting co-participation. Moreover, the changes in thermal sensitivity of root GS transferase activity suggested differential rearrangements of the native enzyme. The amino acid accumulation and composition in roots, xylem sap and leaves deeply changed in response to mineral sources. Glutamine showed the prevalent changes in all nitrogen nutritions. Besides, the ammonium nutrition was associated with an accumulation of asparagine and reducing sugars and a drop in glutamic acid level, significantly alleviated by the co-provision with nitrate. This work provides new information about the multifaceted regulation of the GS enzyme in maize roots, indicating the involvement of specific isoenzymes/isoforms, post

Positional Arrangements of Waste Exhaust Gas Ducts of C-Type Balanced Chimney Heating Devices on Building Façades

Directory of Open Access Journals (Sweden)

Erkan AVLAR

2009-01-01

Full Text Available In Turkey today, with the increase in availability of natural gas,detached heating devices are being preferred over existingheating devices. Due to the lack of chimneys in existing buildingsin Turkey or the presence of chimneys that fail to conformto standards, the use of C-type balanced chimney devices has increased.C-type balanced chimney devices take the combustionair directly from the outside by a specific air duct as detachedheating equipment, with enclosed combustion chambers anda specific waste gas exhaust duct, and they are ventilated independentlyof the field of equipment. Because of their essentiality,the use of a chimney is not required in these devices;the waste gas is exhausted through walls, windows, doors, orbalconies. The natural gas is a clean fossil fuel that requires nostorage in buildings and is easy to use. However, water vapor,carbon dioxide and nitrogen oxides are produced by the combustionof natural gas. It is widely known that high concentrationsof these products can have some adverse effects onhumans such as dizziness, headaches and nausea. As a result,the waste products could recoil through wall openings on thefaçade to create unhealthy indoor environments that could bedangerous to human health. Therefore, the importance of standardsand regulations about the positional arrangements of thewaste gas exhaust ducts of C-type balanced chimney devices onbuilding façades is increasing. In this research, we analyze thestudies of the Institution of Turkish Standards, Chamber of MechanicalEngineers, gas distribution companies, municipalitiesand authorized firms and compare the criteria to determine thenecessary application method. According to our comparison ofthe references accessed, the criteria are not uniform.

Continental-scale footprint of balancing and positive selection in a small rodent (Microtus arvalis.

Directory of Open Access Journals (Sweden)

Martin C Fischer

Full Text Available Genetic adaptation to different environmental conditions is expected to lead to large differences between populations at selected loci, thus providing a signature of positive selection. Whereas balancing selection can maintain polymorphisms over long evolutionary periods and even geographic scale, thus leads to low levels of divergence between populations at selected loci. However, little is known about the relative importance of these two selective forces in shaping genomic diversity, partly due to difficulties in recognizing balancing selection in species showing low levels of differentiation. Here we address this problem by studying genomic diversity in the European common vole (Microtus arvalis presenting high levels of differentiation between populations (average F ST = 0.31. We studied 3,839 Amplified Fragment Length Polymorphism (AFLP markers genotyped in 444 individuals from 21 populations distributed across the European continent and hence over different environmental conditions. Our statistical approach to detect markers under selection is based on a Bayesian method specifically developed for AFLP markers, which treats AFLPs as a nearly codominant marker system, and therefore has increased power to detect selection. The high number of screened populations allowed us to detect the signature of balancing selection across a large geographic area. We detected 33 markers potentially under balancing selection, hence strong evidence of stabilizing selection in 21 populations across Europe. However, our analyses identified four-times more markers (138 being under positive selection, and geographical patterns suggest that some of these markers are probably associated with alpine regions, which seem to have environmental conditions that favour adaptation. We conclude that despite favourable conditions in this study for the detection of balancing selection, this evolutionary force seems to play a relatively minor role in shaping the genomic

A behavioral characterization of the positive real and bounded real characteristic values in balancing

NARCIS (Netherlands)

Trentelman, H.L.

In passivity preserving and bounded realness preserving model reduction by balanced truncation, an important role is played by the so-called positive real (PR) and bounded real (BR) characteristic values. Both for the positive real as well as the bounded real case, these values are defined in terms

Use of nitrogen-15 in soil-plant studies

International Nuclear Information System (INIS)

Sachdev, M.S.; Sachdev, P.; Subbiah, B.V.

1996-01-01

In this paper an overview of the selected work carried out in the country and elsewhere on the fertilizer nitrogen use efficiency, fate and balance-sheet, soil and fertilizer nitrogen transformations and biological nitrogen fixation using 15 N is given. 129 refs., 4 tabs

Nitrogen metabolism and microbial production of dairy cows fed sugarcane and nitrogen compounds

OpenAIRE

Gonçalves,Geógenes da Silva; Pedreira,Marcio dos Santos; Pereira,Mara Lúcia Albuquerque; Santos,Dimas Oliveira; Souza,Dicastro Dias de; Porto Junior,Antonio Ferraz

2014-01-01

The aim of this study was to evaluate the effect of dairy cow diets containing two different sources of urea on nitrogen metabolism and microbial synthesis. Eight crossbred cows were confined and distributed in two 4x4 Latin: FS - soybean meal (control), conventional urea (UC) 100%; ULL 44 UC = 56% / 44% ULL, ULL 88 UC = 12% / 88% ULL. Diets were offered to animals during 21 days with 14 days of adaptation. The N intake, retained nitrogen balance, nitrogen excretion in milk, urine, feces and ...

Determining water and nitrogen balances for beneficial management practices using lysimeters at Wagna test site (Austria).

Science.gov (United States)

Klammler, Gernot; Fank, Johann

2014-11-15

The shallow Murtal aquifer south of Graz, Austria, provides easily withdrawable groundwater, which is supplied as drinking water without any chemical treatment. The aquifer is also used intensively by agriculture. Common agricultural management practices are the main source for diffuse nitrogen leaching and high groundwater nitrate concentrations. To safeguard the coexisting use of these two important resources, lysimeters are operated at the agricultural test site Wagna, Austria, and the influence of two beneficial management practices--low nitrogen input and organic farming--on nitrogen leaching towards groundwater is investigated. The technical lysimeter design as presented here consists of: (1) high-resolution weighing cells, (2) a suction controlled lower boundary condition for sucking off seepage water, thus emulating undisturbed field conditions, (3) comparative soil temperature, water content and matrix potential measurements inside and outside the lysimeter at different depths, (4) an installation of the lysimeters directly into test plots and (5) a removable upper lysimeter ring enabling machinery soil tillage. Our results indicate that oasis effects or fringe effects of the lysimeter cylinder on unsaturated water flow did not occur. Another lysimeter cultivated with lawn is operated for observing grass-reference evapotranspiration, which resulted in good agreement with calculated grass-reference evapotranspiration according to the FAO-Penman-Monteith method. We conclude that lysimeters installed at Wagna test site did not show any fringe effects and, thus, are appropriate tools for measuring water balance elements and nitrogen leaching of arable and grass land at point scale. Furthermore, our results for the period of 2005 to 2011 show that beneficial management practices reduced nitrate leaching and, hence, may allow for a sustainable coexistence of drinking water supply and agriculture in the Murtal aquifer. Copyright © 2014 Elsevier B.V. All rights

Positive affect and cognitive control: approach-motivation intensity influences the balance between cognitive flexibility and stability.

Science.gov (United States)

Liu, Ya; Wang, Zhenhong

2014-05-01

In most prior research, positive affect has been consistently found to promote cognitive flexibility. However, the motivational dimensional model of affect assumes that the influence of positive affect on cognitive processes is modulated by approach-motivation intensity. In the present study, we extended the motivational dimensional model to the domain of cognitive control by examining the effect of low- versus high-approach-motivated positive affect on the balance between cognitive flexibility and stability in an attentional-set-shifting paradigm. Results showed that low-approach-motivated positive affect promoted cognitive flexibility but also caused higher distractibility, whereas high-approach-motivated positive affect enhanced perseverance but simultaneously reduced distractibility. These results suggest that the balance between cognitive flexibility and stability is modulated by the approach-motivation intensity of positive affective states. Therefore, it is essential to incorporate motivational intensity into studies on the influence of affect on cognitive control.

Impacts of climate and management on water balance and nitrogen leaching from montane grassland soils of S-Germany.

Science.gov (United States)

Fu, Jin; Gasche, Rainer; Wang, Na; Lu, Haiyan; Butterbach-Bahl, Klaus; Kiese, Ralf

2017-10-01

In this study water balance components as well as nitrogen and dissolved organic carbon leaching were quantified by means of large weighable grassland lysimeters at three sites (860, 770 and 600 m a.s.l.) for both intensive and extensive management. Our results show that at E600, the site with highest air temperature (8.6 °C) and lowest precipitation (981.9 mm), evapotranspiration losses were 100.7 mm higher as at the site (E860) with lowest mean annual air temperature (6.5 °C) and highest precipitation (1359.3 mm). Seepage water formation was substantially lower at E600 (-440.9 mm) as compared to E860. Compared to climate, impacts of management on water balance components were negligible. However, intensive management significantly increased total nitrogen leaching rates across sites as compared to extensive management from 2.6 kg N ha -1 year -1 (range: 0.5-6.0 kg N ha -1 year -1 ) to 4.8 kg N ha -1 year -1 (range: 0.9-12.9 kg N ha -1 year -1 ). N leaching losses were dominated by nitrate (64.7%) and less by ammonium (14.6%) and DON (20.7%). The low rates of N leaching (0.8-6.9% of total applied N) suggest a highly efficient nitrogen uptake by plants as measured by plant total N content at harvest. Moreover, plant uptake was often exceeding slurry application rates, suggesting further supply of N due to soil organic matter decomposition. The low risk of nitrate losses via leaching and surface runoff of cut grassland on non-sandy soils with vigorous grass growth may call for a careful site and region specific re-evaluation of fixed limits of N fertilization rates as defined by e.g. the German Fertilizer Ordinance following requirements set by the European Water Framework and Nitrates Directive. Copyright © 2017. Published by Elsevier Ltd.

Use of mass and toxicity balances in risk-based corrective action decisions at contaminated sites

International Nuclear Information System (INIS)

Sevigny, J.H.; Lintott, D.; Wrubleski, R.M.; Drury, C.R.

1997-01-01

The contaminated groundwater at a sour gas plant facility was studied to identify the chemicals of environmental concern. Simple mass balance principles were used to determine the proportion of organic carbon, organic nitrogen and Microtox R toxicity that can be attributed to two process chemicals that have contaminated several sour gas plants in western Canada. The two process chemicals are sulfolane and diisopropanolamine (DIPA). The organic carbon balance was calculated by determining the molar contribution of sulfolane and DIPA relative to the mass of carboxylic acid-corrected dissolved organic carbon. Organic carbon balances ranged from 44 to 96 per cent. The organic nitrogen balance was calculated by determining the molar contribution of DIPA relative to the mass of ammonium ion-corrected dissolved Kjeldahl nitrogen. The nitrogen balances were highly variable between 8 to 48 per cent for samples with organic nitrogen concentrations between 10 and 32 mg/L. The Microtox R toxicity balance was calculated by determining the proportions of toxicity that could be accounted for by pure phase sulfolane and DIPA. The Microtox R toxicity balance for samples that showed significant toxicity ranged from 71 to 122 per cent

Use of mass and toxicity balances in risk-based corrective action decisions at contaminated sites

Energy Technology Data Exchange (ETDEWEB)

Sevigny, J.H. [Komex Consultants Ltd., Calgary, AB (Canada); Lintott, D. [HydroQual Consultants, Inc., Calgary, AB (Canada); Wrubleski, R.M.; Drury, C.R. [Shell Canada Ltd., Calgary, AB (Canada). Calgary Research Centre

1997-12-31

The contaminated groundwater at a sour gas plant facility was studied to identify the chemicals of environmental concern. Simple mass balance principles were used to determine the proportion of organic carbon, organic nitrogen and Microtox{sup R} toxicity that can be attributed to two process chemicals that have contaminated several sour gas plants in western Canada. The two process chemicals are sulfolane and diisopropanolamine (DIPA). The organic carbon balance was calculated by determining the molar contribution of sulfolane and DIPA relative to the mass of carboxylic acid-corrected dissolved organic carbon. Organic carbon balances ranged from 44 to 96 per cent. The organic nitrogen balance was calculated by determining the molar contribution of DIPA relative to the mass of ammonium ion-corrected dissolved Kjeldahl nitrogen. The nitrogen balances were highly variable between 8 to 48 per cent for samples with organic nitrogen concentrations between 10 and 32 mg/L. The Microtox{sup R} toxicity balance was calculated by determining the proportions of toxicity that could be accounted for by pure phase sulfolane and DIPA. The Microtox{sup R} toxicity balance for samples that showed significant toxicity ranged from 71 to 122 per cent.

Errors in potassium balance

International Nuclear Information System (INIS)

Forbes, G.B.; Lantigua, R.; Amatruda, J.M.; Lockwood, D.H.

1981-01-01

Six overweight adult subjects given a low calorie diet containing adequate amounts of nitrogen but subnormal amounts of potassium (K) were observed on the Clinical Research Center for periods of 29 to 40 days. Metabolic balance of potassium was measured together with frequent assays of total body K by 40 K counting. Metabolic K balance underestimated body K losses by 11 to 87% (average 43%): the intersubject variability is such as to preclude the use of a single correction value for unmeasured losses in K balance studies

Convergent evidence for widespread rock nitrogen sources in Earth’s surface environment

Science.gov (United States)

Houlton, B. Z.; Morford, S. L.; Dahlgren, R. A.

2018-04-01

Nitrogen availability is a pivotal control on terrestrial carbon sequestration and global climate change. Historical and contemporary views assume that nitrogen enters Earth’s land-surface ecosystems from the atmosphere. Here we demonstrate that bedrock is a nitrogen source that rivals atmospheric nitrogen inputs across major sectors of the global terrestrial environment. Evidence drawn from the planet’s nitrogen balance, geochemical proxies, and our spatial weathering model reveal that ~19 to 31 teragrams of nitrogen are mobilized from near-surface rocks annually. About 11 to 18 teragrams of this nitrogen are chemically weathered in situ, thereby increasing the unmanaged (preindustrial) terrestrial nitrogen balance from 8 to 26%. These findings provide a global perspective to reconcile Earth’s nitrogen budget, with implications for nutrient-driven controls over the terrestrial carbon sink.

A reactive nitrogen budget for Lake Michigan

Science.gov (United States)

The reactive nitrogen budget for Lake Michigan was reviewed and updated, making use of recent estimates of watershed and atmospheric nitrogen loads. The updated total N load to Lake Michigan was approximately double the previous estimate from the Lake Michigan Mass Balance study ...

Convergent evidence for widespread rock nitrogen sources in Earth's surface environment.

Science.gov (United States)

Houlton, B Z; Morford, S L; Dahlgren, R A

2018-04-06

Nitrogen availability is a pivotal control on terrestrial carbon sequestration and global climate change. Historical and contemporary views assume that nitrogen enters Earth's land-surface ecosystems from the atmosphere. Here we demonstrate that bedrock is a nitrogen source that rivals atmospheric nitrogen inputs across major sectors of the global terrestrial environment. Evidence drawn from the planet's nitrogen balance, geochemical proxies, and our spatial weathering model reveal that ~19 to 31 teragrams of nitrogen are mobilized from near-surface rocks annually. About 11 to 18 teragrams of this nitrogen are chemically weathered in situ, thereby increasing the unmanaged (preindustrial) terrestrial nitrogen balance from 8 to 26%. These findings provide a global perspective to reconcile Earth's nitrogen budget, with implications for nutrient-driven controls over the terrestrial carbon sink. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Positive and negative effects of nitrogen compounds on plants in the vicinity of a fertilizer factory

Energy Technology Data Exchange (ETDEWEB)

Scholl, G

1975-05-01

At a distance of 300 m from a fertilizer plant, various grains and fodder plants, as well as spinach, string beans, and peas, were grown consecutively over a period of several years to determine the effects of various concentrations of nitrogen compounds emitted by a fertilizer plant on the cultivations. Injuries that were similar to those observed in fumigation experiments with nitrogen dioxide were observed in the leaves of the experimental plants. In relatively high concentrations, pollutants containing nitrogen were as toxic as sulfur dioxide. Lower concentrations had a positive stimulatory effect and increased vegetative growth. Legumes were the most sensitive to nitrogen pollutants. Production of chlorophyll was reduced in lupine and Alexandrine clover, although no visible injuries were observed. Nodule development of the lupine was significantly restricted. The contamination of food and fodder plants by nitrates was significant and was found to present a real danger to humans through the food chain.

Forest fuel reduces the nitrogen load - calculations of nitrogen flows

International Nuclear Information System (INIS)

Burstroem, F.; Johansson, Jan.

1995-12-01

Nitrogen deposition in Sweden has increased strongly during recent decades, particularly in southern Sweden. Nitrogen appears to be largely accumulated in biomass and in the soil. It is therefore desirable to check the accumulation of nitrogen in the forest. The most suitable way of doing this is to remove more nitrogen-rich biomass from the forest, i.e., increase the removal of felling residues from final fellings and cleanings. An ecological condition for intensive removal of fuel is that the ashes are returned. The critical load for nitrogen, CL(N), indicates the level of nitrogen deposition that the forest can withstand without leading to ecological changes. Today, nitrogen deposition is higher than the CL(N) in almost all of Sweden. CL(N) is calculated in such a manner that nitrogen deposition should largely be balanced by nitrogen losses through harvesting during a forest rotation. The value of CL(N) thus largely depends on how much nitrogen is removed with the harvested biomass. When both stems and felling residues are harvested, the CL(N) is about three times higher than in conventional forestry. The increase is directly related to the amount of nitrogen in the removed biofuel. Use of biofuel also causes a certain amount of nitrogen emissions. From the environmental viewpoint there is no difference between the sources of the nitrogen compounds. An analysis of the entire fuel chain shows that, compared with the amount of nitrogen removed from the forest with the fuel, about 5 % will be emitted as nitrogen oxides or ammonia during combustion, and a further ca 5 % during handling and transports. A net amount of about 90 % of biomass nitrogen is removed from the system and becomes inert nitrogen (N 2 ). 60 refs, 3 figs, 4 tabs, 11 appendices

Achieving Lower Nitrogen Balance and Higher Nitrogen Recovery Efficiency Reduces Nitrous Oxide Emissions in North America's Maize Cropping Systems

Directory of Open Access Journals (Sweden)

Rex A. Omonode

2017-06-01

Full Text Available Few studies have assessed the common, yet unproven, hypothesis that an increase of plant nitrogen (N uptake and/or recovery efficiency (NRE will reduce nitrous oxide (N2O emission during crop production. Understanding the relationships between N2O emissions and crop N uptake and use efficiency parameters can help inform crop N management recommendations for both efficiency and environmental goals. Analyses were conducted to determine which of several commonly used crop N uptake-derived parameters related most strongly to growing season N2O emissions under varying N management practices in North American maize systems. Nitrogen uptake-derived variables included total aboveground N uptake (TNU, grain N uptake (GNU, N recovery efficiency (NRE, net N balance (NNB in relation to GNU [NNB(GNU] and TNU [NNB(TNU], and surplus N (SN. The relationship between N2O and N application rate was sigmoidal with relatively small emissions for N rates <130 kg ha−1, and a sharp increase for N rates from 130 to 220 kg ha−1; on average, N2O increased linearly by about 5 g N per kg of N applied for rates up to 220 kg ha−1. Fairly strong and significant negative relationships existed between N2O and NRE when management focused on N application rate (r2 = 0.52 or rate and timing combinations (r2 = 0.65. For every percentage point increase, N2O decreased by 13 g N ha−1 in response to N rates, and by 20 g N ha−1 for NRE changes in response to rate-by-timing treatments. However, more consistent positive relationships (R2 = 0.73–0.77 existed between N2O and NNB(TNU, NNB(GNU, and SN, regardless of rate and timing of N application; on average N2O emission increased by about 5, 7, and 8 g N, respectively, per kg increase of NNB(GNU, NNB(TNU, and SN. Neither N source nor placement influenced the relationship between N2O and NRE. Overall, our analysis indicated that a careful selection of appropriate N rate applied at the right time can both increase NRE and reduce N

Comparison of ion balance and nitrogen metabolism in old and young leaves of alkali-stressed rice plants.

Science.gov (United States)

Wang, Huan; Wu, Zhihai; Han, Jiayu; Zheng, Wei; Yang, Chunwu

2012-01-01

Alkali stress is an important agricultural contaminant and has complex effects on plant metabolism. The aim of this study was to investigate whether the alkali stress has different effects on the growth, ion balance, and nitrogen metabolism in old and young leaves of rice plants, and to compare functions of both organs in alkali tolerance. The results showed that alkali stress only produced a small effect on the growth of young leaves, whereas strongly damaged old leaves. Rice protected young leaves from ion harm via the large accumulation of Na(+) and Cl(-) in old leaves. The up-regulation of OsHKT1;1, OsAKT1, OsHAK1, OsHAK7, OsHAK10 and OsHAK16 may contribute to the larger accumulation of Na(+) in old leaves under alkali stress. Alkali stress mightily reduced the NO(3)(-) contents in both organs. As old leaf cells have larger vacuole, under alkali stress these scarce NO(3)(-) was principally stored in old leaves. Accordingly, the expression of OsNRT1;1 and OsNRT1;2 in old leaves was up-regulated by alkali stress, revealing that the two genes might contribute to the accumulation of NO(3)(-) in old leaves. NO(3)(-) deficiency in young leaves under alkali stress might induce the reduction in OsNR1 expression and the subsequent lacking of NH(4)(+), which might be main reason for the larger down-regulation of OsFd-GOGAT and OsGS2 in young leaves. Our results strongly indicated that, during adaptation of rice to alkali stress, young and old leaves have distinct mechanisms of ion balance and nitrogen metabolism regulation. We propose that the comparative studies of young and old tissues may be important for abiotic stress tolerance research.

Digestibility and nitrogen balance of diets containing non conventional vegetable proteins fed to pigs of genetic strains suitable for outdoor systems

OpenAIRE

L. Sardi; M. Simioli; R. Paganelli; G. Martelli; L. Rizzi

2010-01-01

The study was carried out to evaluate on growing pigs kept in metabolism crates, either belonging to a “traditional” cross-breed (Duroc x Large White – DLW) or a local breed (Cinta Senese – CS), the digestibility and the nitrogen balance of non-conventional vegetable protein sources (field beans, pea and sunflower cake) when compared to soybean meal. The four diets were formulated so as to supply the same crude protein amount. CS pigs showed lower apparent digestibilit...

Nitrogen balances of innovative cropping systems for feedstock production to future biorefineries

DEFF Research Database (Denmark)

Manevski, Kiril; Lærke, Poul Erik; Olesen, Jørgen Eivind

2018-01-01

maize monoculture, the optimised rotation supplied 70% more biomass N and 40% less nitrate leaching on coarse sandy soil, whereas on sandy loam soil it yielded about 10% less biomass N with 50% less nitrate leaching. Field surface N balances were overall neutral/positive, except for festulolium...... and continuous maize monoculture that slightly mined the soil for N. When N losses by leaching, denitrification and volatilisation were included, soil total N stocks were estimated to decline for the majority of the systems at both sites....

Technique for positioning hologram for balancing large data capacity with fast readout

Science.gov (United States)

Shimada, Ken-ichi; Hosaka, Makoto; Yamazaki, Kazuyoshi; Onoe, Shinsuke; Ide, Tatsuro

2017-09-01

The technical difficulty of balancing large data capacity with a high data transfer rate in holographic data storage systems (HDSSs) is significantly high because of tight tolerances for physical perturbation. From a system margin perspective in terabyte-class HDSSs, the positioning error of a holographic disc should be within about 10 µm to ensure high readout quality. Furthermore, fine control of the positioning should be accomplished within a time frame of about 10 ms for a high data transfer rate of the Gbps class, while a conventional method based on servo control of spindle or sled motors can rarely satisfy the requirement. In this study, a new compensation method for the effect of positioning error, which precisely controls the positioning of a Nyquist aperture instead of a holographic disc, has been developed. The method relaxes the markedly low positional tolerance of a holographic disc. Moreover, owing to the markedly light weight of the aperture, positioning control within the required time frame becomes feasible.

[Inventory of regional surface nutrient balance and policy recommendations in China].

Science.gov (United States)

Chen, Min-Peng; Chen, Ji-Ning

2007-06-01

By applying OECD surface soil nitrogen balance methodology, the framework, methodology and database for nutrient balance budget in China are established to evaluate the impact of nutrient balance on agricultural production and water environment. Results show that nitrogen and phosphorus surplus in China are 640 x 10(4) t and 98 x 10(4) t respectively, and nitrogen and phosphorus surplus intensity in China are 16.56 kg/hm2 and 2.53 kg/hm2 respectively. Because of striking spatial difference of nutrient balance across the country, China is seeing a dual-challenge of nutrient surplus management as well as nutrient deficit management. Chemical fertilizer and livestock manure are best targets to perform nutrient surplus management due to their marked contributions to nutrient input. However, it is not cost-effective to implement a uniform management for all regions since nutrient input structures of them vary considerably.

Socioeconomic position and outdoor nitrogen dioxide (NO2) exposure in Western Europe : A multi-city analysis

NARCIS (Netherlands)

Temam, Sofia; Burte, Emilie; Adam, Martin; Antó, Josep M; Basagaña, Xavier; Bousquet, Jean; Carsin, Anne-Elie; Galobardes, Bruna; Keidel, Dirk; Künzli, Nino; Le Moual, Nicole; Sanchez, Margaux; Sunyer, Jordi; Bono, Roberto; Brunekreef, Bert; Heinrich, Joachim; de Hoogh, Kees; Jarvis, Debbie; Marcon, Alessandro; Modig, Lars; Nadif, Rachel; Nieuwenhuijsen, Mark; Pin, Isabelle; Siroux, Valérie; Stempfelet, Morgane; Tsai, Ming-Yi; Probst-Hensch, Nicole; Jacquemin, Bénédicte

BACKGROUND: Inconsistent associations between socioeconomic position (SEP) and outdoor air pollution have been reported in Europe, but methodological differences prevent any direct between-study comparison. OBJECTIVES: Assess and compare the association between SEP and outdoor nitrogen dioxide (NO2)

Optimization of manuring with fermentation residues in order to reduce the nitrogen emissions and optimization of the humus balance; Optimierung der Gaerrestduengung zur Reduzierung der Stickstoffemissionen und Optimierung der Humusbilanz

Energy Technology Data Exchange (ETDEWEB)

Moeller, Kurt [Hohenheim Univ., Stuttgart (Germany). Inst. fuer Kulturpflanzenwissenschaften

2011-07-01

On the one hand, the introduction of a biogas plant is connected with the possibility of optimizing the internal nutrient cycles and the reduction of nitrogen losses. On the other hand, the improper handling of the digestate and ''stupid'' cropping systems increase the nitrogen emissions significantly. Therefore, biogas plants are faced with many challenges in order to optimize the nutrient cycling, to reduce their nitrogen losses to a minimum and to keep the humus balance in mind. From this perspective, the author of the contribution under consideration reports on some opportunities for optimization.

Modeling nitrogen fluxes in Germany - where does the nitrogen go?

Science.gov (United States)

Klement, Laura; Bach, Martin; Breuer, Lutz

2016-04-01

According to the latest inventory of the EU Water Framework Directive, 26.3% of German groundwater bodies are in a poor chemical state regarding nitrate. Additionally, the EU initiated infringement proceedings against Germany for not meeting the quality standards of the EU Nitrate Directive. Agriculture has been determined as the main source of nitrate pollution due to over-fertilization and regionally high density of livestock farming. The nitrogen balance surplus is commonly used as an indicator characterizing the potential of nitrate leaching into groundwater bodies and thus also serves as a foundation to introduce legislative restrictions or to monitor the success of mitigation measures. Currently, there is an ongoing discussion which measures are suitable for reducing the risk of nitrate leaching and also to what extent. However, there is still uncertainty about just how much the nitrogen surplus has to be reduced to meet the groundwater quality standards nationwide. Therefore, the aims of our study were firstly to determine the level of the nitrogen surplus that would be acceptable at the utmost and secondly whether the currently discussed target value of 30 kg N per hectare agricultural land for the soil surface nitrogen balance would be sufficient. The models MONERIS (Modeling Nutrient Emissions in River System) and MoRE (Modelling of Regionalized Emissions), the latter based on the first, are commonly used for estimating nitrogen loads into the river system in Germany at the mesoscale, as well as the effect of mitigation measures in the context of the EU directive 2008/105/EC (Environmental quality standards applicable to surface water). We used MoRE to calculate nitrate concentration for 2759 analytical units in Germany. Main factors are the surplus of the soil surface nitrogen balance, the percolation rate and an exponent representing the denitrification in the vadose zone. The modeled groundwater nitrate concentrations did not correspond to the regional

Nitrogen isotope tracing of dissolved inorganic nitrogen behaviour in tidal estuaries

NARCIS (Netherlands)

Middelburg, J.J.; Nieuwenhuize, J.

2001-01-01

Concentration versus salinity diagrams are the most widely used method to derive estuarine sources and sinks of nitrogen. This method can not distinguish conservative mixing due to a lack of activity, from that due to an approximate balance of sources and sinks. The combined study of concentration

Inorganic nitrogen in precipitation and atmospheric sediments

Energy Technology Data Exchange (ETDEWEB)

Matheson, D H

1951-01-01

In an investigation covering 18 months, daily determinations were made of the inorganic nitrogen contained in precipitation and atmospheric sediments collected at Hamilton, Ont. The nitrogen fall for the whole period averaged 5.8 lb. N per acre per year. Sixty-one per cent of the total nitrogen was collected on 25% of the days when precipitation occurred. The balance, occurring on days without precipitation, is attributable solely to the sedimentation of dust. Ammonia nitrogen averaged 56% of the total, but the proportion for individual days varied widely.

Total Protein Content Determination of Microalgal Biomass by Elemental Nitrogen Analysis and a Dedicated Nitrogen-to-Protein Conversion Factor

Energy Technology Data Exchange (ETDEWEB)

Laurens, Lieve M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Olstad-Thompson, Jessica L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Templeton, David W [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-04-02

Accurately determining protein content is important in the valorization of algal biomass in food, feed, and fuel markets, where these values are used for component balance calculations. Conversion of elemental nitrogen to protein is a well-accepted and widely practiced method, but depends on developing an applicable nitrogen-to-protein conversion factor. The methodology reported here covers the quantitative assessment of the total nitrogen content of algal biomass and a description of the methodology that underpins the accurate de novo calculation of a dedicated nitrogen-to-protein conversion factor.

Enzymology and ecology of the nitrogen cycle.

Science.gov (United States)

Martínez-Espinosa, Rosa María; Cole, Jeffrey A; Richardson, David J; Watmough, Nicholas J

2011-01-01

The nitrogen cycle describes the processes through which nitrogen is converted between its various chemical forms. These transformations involve both biological and abiotic redox processes. The principal processes involved in the nitrogen cycle are nitrogen fixation, nitrification, nitrate assimilation, respiratory reduction of nitrate to ammonia, anaerobic ammonia oxidation (anammox) and denitrification. All of these are carried out by micro-organisms, including bacteria, archaea and some specialized fungi. In the present article, we provide a brief introduction to both the biochemical and ecological aspects of these processes and consider how human activity over the last 100 years has changed the historic balance of the global nitrogen cycle.

Generating a positive energy balance from using rice straw for anaerobic digestion

Directory of Open Access Journals (Sweden)

V.H. Nguyen

2016-11-01

The net energy of the rice straw supply chain for biogas generation through AD is 3,500 MJ per ton of straw. This rice straw management option can provide a 70% net output energy benefit. The research highlighted the potential of rice straw as a clean fuel source with a positive energy balance, helping to reduce greenhouse gas emissions compared with the existing practice of burning it in the field.

A Comparative Nitrogen Balance and Productivity Analysis of Legume and Non-legume Supported Cropping Systems: The Potential Role of Biological Nitrogen Fixation.

Science.gov (United States)

Iannetta, Pietro P M; Young, Mark; Bachinger, Johann; Bergkvist, Göran; Doltra, Jordi; Lopez-Bellido, Rafael J; Monti, Michele; Pappa, Valentini A; Reckling, Moritz; Topp, Cairistiona F E; Walker, Robin L; Rees, Robert M; Watson, Christine A; James, Euan K; Squire, Geoffrey R; Begg, Graham S

2016-01-01

The potential of biological nitrogen fixation (BNF) to provide sufficient N for production has encouraged re-appraisal of cropping systems that deploy legumes. It has been argued that legume-derived N can maintain productivity as an alternative to the application of mineral fertilizer, although few studies have systematically evaluated the effect of optimizing the balance between legumes and non N-fixing crops to optimize production. In addition, the shortage, or even absence in some regions, of measurements of BNF in crops and forages severely limits the ability to design and evaluate new legume-based agroecosystems. To provide an indication of the magnitude of BNF in European agriculture, a soil-surface N-balance approach was applied to historical data from 8 experimental cropping systems that compared legume and non-legume crop types (e.g., grains, forages and intercrops) across pedoclimatic regions of Europe. Mean BNF for different legume types ranged from 32 to 115 kg ha -1 annually. Output in terms of total biomass (grain, forage, etc.) was 30% greater in non-legumes, which used N to produce dry matter more efficiently than legumes, whereas output of N was greater from legumes. When examined over the crop sequence, the contribution of BNF to the N-balance increased to reach a maximum when the legume fraction was around 0.5 (legume crops were present in half the years). BNF was lower when the legume fraction increased to 0.6-0.8, not because of any feature of the legume, but because the cropping systems in this range were dominated by mixtures of legume and non-legume forages to which inorganic N as fertilizer was normally applied. Forage (e.g., grass and clover), as opposed to grain crops in this range maintained high outputs of biomass and N. In conclusion, BNF through grain and forage legumes has the potential to generate major benefit in terms of reducing or dispensing with the need for mineral N without loss of total output.

A comparative nitrogen balance and productivity analysis of legume and non-legume supported cropping systems: the potential role of biological nitrogen fixation

Directory of Open Access Journals (Sweden)

Pietro P M Iannetta

2016-11-01

Full Text Available The potential of biological nitrogen fixation (BNF to provide sufficient N for production have encouraged re-appraisal of cropping systems that deploy legumes. It has been argued that legume-derived N can maintain productivity as an alternative to the application of mineral fertiliser, although few studies have systematically evaluated the effect of optimising the balance between legumes and non N-fixing crops to optimise production. In addition, the shortage, or even absence in some regions, of measurements of BNF in crops and forages severely limits the ability to design and evaluate new, legume–based agroecosystems. To provide an indication of the magnitude of BNF in European agriculture, a soil-surface N-balance approach was applied to historical data from 8 experimental cropping systems that compared legume and non-legume crop types (e.g. grains, forages and intercrops across pedoclimatic regions of Europe. Mean BNF for different legume types ranged from 32-115 kg ha-1 annually. Output in terms of total biomass (grain, forage, etc. was 30% greater in non-legumes, which used N to produce dry matter more efficiently than legumes, whereas output of N was greater from legumes. When examined over the crop sequence, the contribution of BNF to the N-balance increased to reach a maximum when the legume fraction was around 0.5 (legume crops were present in half the years. BNF was lower when the legume fraction increased to 0.6-0.8, not because of any feature of the legume, but because the cropping systems in this range were dominated by mixtures of legume and non-legume forages to which inorganic N as fertiliser was normally applied. Forage (e.g. grass and clover, as opposed to grain crops in this range maintained high outputs of biomass and N. In conclusion, BNF through grain and forage legumes have the potential to generate major benefit in terms of reducing or dispensing with the need for mineral N without loss of total output.

Studies involving tracer techniques for certain nutritional aspects of nitrogen and phosphorus with reference to fertilization of wheat plant

International Nuclear Information System (INIS)

Rizk, M. A.

1987-01-01

Two short-term experiments were carried out to study the mutual effects between nitrogen and phosphatic fertilizers, wheat seedlings being the indicator plant grown on different soil types, namely; sandy loam of inshas, clay of bahtim and calcareous of salheya. Response of wheat plants to mutual interactions between applied nitrogenous and phosphatic fertilizers. 1- Dry matter content of wheat seedlings are significantly affected by the interactions between sources of nitrogen and phosphorus for the investigated seedlings which may reflect the importance of ion balance between the two concerned elements. 2- Nitrogen content in the two weeks old seedlings is positively affected with the interaction between P-source (ortho and poly-phosphate), nitrogen level and nitrogen source.3- A positive response of total P- uptaken by wheat plants for the rate of applied nitrogenous fertilizer is observed, trend being attributed to influence of nitrogen on the status of P in the soil adjacent to roots as to have a concentration gradient suitable for absorption. 4- Except for nitrogen rate, other parameters and certain interactions have been generally not significantly effective on P - in plant derived from both fertilizer and soil. 5- Utilization percentages of the used P- fertilizer show significant responses to applied N- rate along with interactions with source of applied N and P nutritional elements with one week old plants

Potassium deficiency affects the carbon-nitrogen balance in cotton leaves.

Science.gov (United States)

Hu, Wei; Coomer, Taylor D; Loka, Dimitra A; Oosterhuis, Derrick M; Zhou, Zhiguo

2017-06-01

Potassium (K) plays important roles in the metabolism of carbon (C) and nitrogen (N), but studies of K deficiency affecting C-N balance are lacking. This study explored the influence of K deficiency on C-N interaction in cotton leaves by conducting a field experiment with cotton cultivar DP0912 under two K rates (K0: 0 kg K 2 O ha -1 and K67: 67 kg K 2 O ha -1 ) and a controlled environment experiment with K-deficient solution (K1: 0 mM K + ) and K-sufficient solution (K2: 6 mM K + ). The results showed that leaf K content, leaf number, leaf area, boll number, reproductive dry weight and total dry weight were significant lower under K deficiency (K0 or K1). Lower total chlorophyll content and Chl a/b ratio, and decreased Pn along with lower Gs and higher Ci were measured under K deficiency, suggesting that the decrease in Pn was resulted from non-stomatal limitation. Leaf glucose, fructose, sucrose and starch contents were higher under K deficiency, because lower sucrose export was detected in phloem. Although leaf nitrate and ammonium contents significantly decreased, free amino acid content was increased by 40-63% under K deficiency, since lower amino acid export was also measured in phloem. K deficiency also induced lower soluble protein content in leaves. Leaf ATP level was significantly increased under K deficiency, indicating ATP utilization was lower, so that less energy was supplied to C and N metabolism. The ratio of soluble sugar to free amino acid and the C/N ratio markedly increased under K deficiency, and one reason was that the phloem export reduced more prominent for sucrose (54.6-78.0%) than amino acid (36.7-85.4%) under K deficiency. In addition, lower phosphoenolpyruvate carboxylase activity limited malate and citrate biosynthesis under K deficiency, causing a decrease of C flux into the amino acids, which was not beneficial for maintaining C-N balance. Sucrose phosphate synthase and nitrate reductase activities were lower under K deficiency

Interactions between nitrogen deposition, land cover conversion, and climate change determine the contemporary carbon balance of Europe

Science.gov (United States)

Churkina, G.; Zaehle, S.; Hughes, J.; Viovy, N.; Chen, Y.; Jung, M.; Heumann, B. W.; Ramankutty, N.; Heimann, M.; Jones, C.

2010-09-01

European ecosystems are thought to take up large amounts of carbon, but neither the rate nor the contributions of the underlying processes are well known. In the second half of the 20th century, carbon dioxide concentrations have risen by more that 100 ppm, atmospheric nitrogen deposition has more than doubled, and European mean temperatures were increasing by 0.02 °C yr-1. The extents of forest and grasslands have increased with the respective rates of 5800 km2 yr-1 and 1100 km2 yr-1 as agricultural land has been abandoned at a rate of 7000 km2 yr-1. In this study, we analyze the responses of European land ecosystems to the aforementioned environmental changes using results from four process-based ecosystem models: BIOME-BGC, JULES, ORCHIDEE, and O-CN. The models suggest that European ecosystems sequester carbon at a rate of 56 TgC yr-1 (mean of four models for 1951-2000) with strong interannual variability (±88 TgC yr-1, average across models) and substantial inter-model uncertainty (±39 TgC yr-1). Decadal budgets suggest that there has been a continuous increase in the mean net carbon storage of ecosystems from 85 TgC yr-1 in 1980s to 108 TgC yr-1 in 1990s, and to 114 TgC yr-1 in 2000-2007. The physiological effect of rising CO2 in combination with nitrogen deposition and forest re-growth have been identified as the important explanatory factors for this net carbon storage. Changes in the growth of woody vegetation are suggested as an important contributor to the European carbon sink. Simulated ecosystem responses were more consistent for the two models accounting for terrestrial carbon-nitrogen dynamics than for the two models which only accounted for carbon cycling and the effects of land cover change. Studies of the interactions of carbon-nitrogen dynamics with land use changes are needed to further improve the quantitative understanding of the driving forces of the European land carbon balance.

Characterization of static balance abilities in elite soccer players by playing position and age.

Science.gov (United States)

Pau, Massimiliano; Ibba, Gianfranco; Leban, Bruno; Scorcu, Marco

2014-01-01

In this study, we investigated the static balance of adult and adolescent elite soccer players to understand how expertise and playing position influence postural control. Seventy-one national level players were tested using a force platform to acquire Center-of-Pressure (COP) data in uni- and bipedal stance and calculate sway area (SA), COP path length, velocity and displacements. The results show significant differences in postural sway related to age and playing position only for single-limb stance. In particular, midfielders exhibited significantly lower values of SA with respect to defenders (-48%, p = 0.001) and the under-15 players exhibited SA 42-64% higher than all the others (p = 0.001). In the light of planning training or rehabilitation programs specific for each player's role and age, sway measurements may supply useful, objective and reliable information only for the unipedal test as the bipedal standing appears not challenging enough to let differences in balance abilities emerge.

The interpretation of static positional nystagmus in a balance clinic.

Science.gov (United States)

Jeffery, Hanna; Hopkins, Matthew; Anderson, Rebecca; Patel, Vignapti; Rogers, Jennifer

2017-12-01

To review the current criteria for the interpretation of positional nystagmus (PN). Videonystagmography data on PN was collected for 90 patients presenting for balance testing with a history of vertigo or imbalance (excluding those diagnosed with benign paroxysmal positional vertigo). These were compared to normative data from 90 asymptomatic subjects. A literature review was carried out regarding threshold criteria for clinically significant PN. These were evaluated using the data collected. Clinic group: 90 patients; 37 male, 53 female. Age range 15-82 years. Normative group: Ninety subjects; 31 male, 59 female. Age range 21-79 years. PN was seen in 75.6% of the clinic group and in 50% of the normative group. The prevalence of nystagmus of slow phase velocity (SPV) > 3°/s was significantly higher in the clinic group than the normative group. The maximum SPV recorded in each position was greater from the clinic group than the normative group. This study supports the use of normative thresholds for SPV for both horizontal and vertical PN. A normative threshold of >3°/s for horizontal and >7°/s for vertical nystagmus is proposed.

The evaluation of body mass index, balance and agility features of amateur soccer players according to their positions

Directory of Open Access Journals (Sweden)

Kamil Erdem

2015-12-01

Full Text Available Aim: The purpose of this study was to compare of body mass index (BMI, balance and agility features of soccer players at different positions and to investigate the relation between these features. Material and Methods: Research was carried out on 44 amateur soccer player whom played in different positions in various teams that compete in amateur league of İstanbul. In the research, it was tested vki, balance, agility with ball and agility without ball on soccer players. The average of variables was taken and Kruskal Wallis nonparametric variance analysis was used to determine the difference between groups. Pearson correlation was used to determine correlations between variables. Results: As a result of measuments, when compare between positions, it was found that there was a statistical difference on body mass measurement (p0,01. As a result of correlations, it was found statistically significant relation between body mass and agility with ball between BMI and agility with ball and between body mass and BMI variables (p<0,01. Conclusion: As a result of assesstments it has been revealed that there was a correlation between BMI and dribbling skills on soccer players however there wasn’t found any differences between other parameters as balance and agility because of the trainings that carried out regardless of the positions in soccer. As a conclusion, optimal training programmes that will be held on according to positions of players, additional balance trainings and the identified shortcomings may contribute to the development of soccer players performance and skill with appliying ideal diet programme to maintain the appropriate body weight for players heights.

Influence of different fibre sources on digestibility and nitrogen and energy balances in growing pigs

DEFF Research Database (Denmark)

Hansen, Michael Jørgen; Chwalibog, André; Tauson, Anne-Helene

2006-01-01

The present study was undertaken to investigate how three different fibre sources, sugar beet pulp, soya bean hulls and pectin residue, constituting 15% of diets for growing pigs, influenced daily body gain, feed conversion, apparent faecal digestibility and nitrogen and energy balances. Eight......) and energy were significantly lower for the fibre diets (OM: 0.81-0.85; energy: 0.78-0.83) compared to the control diet (OM: 0.88; energy: 0.86). The apparent faecal digestibility of crude protein (CP) was lower for the fibre diets (0.71-0.78) compared to the control diet (0.83), although it was only...... significantly lower for the sugar beet pulp and pectin residue diets. The pectin residue diet, which contained the highest amount of dietary fibre, lignin and insoluble non-starch polysaccharides, had the lowest digestibility of OM, CP and energy. There was a tendency (p = 0.07) for a diet effect on retained...

Characteristics of nitrogen balance in open-air and greenhouse vegetable cropping systems of China.

Science.gov (United States)

Ti, Chaopu; Luo, Yongxia; Yan, Xiaoyuan

2015-12-01

Nitrogen (N) loss from vegetable cropping systems has become a significant environmental issue in China. In this study, estimation of N balances in both open-air and greenhouse vegetable cropping systems in China was established. Results showed that the total N input in open-air and greenhouse vegetable cropping systems in 2010 was 5.44 and 2.60 Tg, respectively. Chemical fertilizer N input in the two cropping systems was 201 kg N ha(-1) per season (open-air) and 478 kg N ha(-1) per season (greenhouse). The N use efficiency (NUE) was 25.9 ± 13.3 and 19.7 ± 9.4% for open-air and greenhouse vegetable cropping systems, respectively, significantly lower than that of maize, wheat, and rice. Approximately 30.6% of total N input was accumulated in soils and 0.8% was lost by ammonia volatilization in greenhouse vegetable system, while N accumulation and ammonia volatilization accounted for 19.1 and 11.1%, respectively, of total N input in open-air vegetable systems.

A bibliometric review of nitrogen research in eutrophic lakes and reservoirs.

Science.gov (United States)

Yao, Xiaolong; Zhang, Yunlin; Zhang, Lu; Zhou, Yongqiang

2018-04-01

The global application of nitrogen is far greater than phosphorus, and it is widely involved in the eutrophication of lakes and reservoirs. We used a bibliometric method to quantitatively and qualitatively evaluate nitrogen research in eutrophic lakes and reservoirs to reveal research developments, current research hotspots, and emerging trends in this area. A total of 2695 articles in the past 25years from the online database of the Scientific Citation Index Expended (SCI-Expanded) were analyzed. Articles in this area increased exponentially from 1991 to 2015. Although the USA was the most productive country over the past 25years, China achieved the top position in terms of yearly publications after 2010. The most active keywords related to nitrogen in the past 25years included phosphorus, nutrients, sediment, chlorophyll-a, carbon, phytoplankton, cyanobacteria, water quality, modeling, and stable isotopes, based on analysis within 5-year intervals from 1991 to 2015 as well as the entire past 25years. In addition, researchers have drawn increasing attention to denitrification, climate change, and internal loading. Future trends in this area should focus on: (1) nutrient amounts, ratios, and major nitrogen sources leading to eutrophication; (2) nitrogen transformation and the bioavailability of different nitrogen forms; (3) nitrogen budget, mass balance model, control, and management; (4) ecosystem responses to nitrogen enrichment and reduction, as well as the relationships between these responses; and (5) interactions between nitrogen and other stressors (e.g., light intensity, carbon, phosphorus, toxic contaminants, climate change, and hydrological variations) in terms of eutrophication. Copyright © 2017. Published by Elsevier B.V.

How Positivity Links With Job Satisfaction: Preliminary Findings on the Mediating Role of Work-Life Balance

OpenAIRE

Orkibi, Hod; Brandt, Yaron Ilan

2015-01-01

The positive characteristics that can help people juggle their work and personal roles and experience greater job satisfaction are attracting increased research attention. This study presents a conceptual model to account for the association between employees’ positive orientation (i.e., the tendency to evaluate self, life, and the future in a positive way) and their job satisfaction (N = 108). As theorized, the results indicate that employees’ ability to manage their work-life balance fully ...

The Role of Ethnic Culture in Work-Family Balance among Armenian Women in Leadership Positions in Higher Education

Science.gov (United States)

Baran, Hasmig

2012-01-01

In contemporary society women leaders in education have struggled to balance work and family. While some women have succeeded in finding that balance, many others are still struggling. The purpose of this qualitative study was to examine the experiences of three Armenian women in senior-level leadership positions in higher education in the United…

Nitrogen balance and dynamics in corn under different soil fertility levels using “1“5N isotope tracer technique

International Nuclear Information System (INIS)

Rallos, R.V.; Rivera, F.G.; Samar, E.D.; Rojales, J.S.; Anida, A.H.

2015-01-01

Nitrogen (N) Fertilizer plays a vital role on the growth and development of any crop. The inefficient N fertilizer utilization contributes to poor crop productivity and environment pollution. This study used the 15N isotope tracer technique to understand the nitrogen balance and dynamics in corn grown during the wet and dry season for low, medium and high N soils in Northern Luzon. The experiments were laid out following the randomized complete block design (RCBD) potassium requirements were applied at optimum level on solid chemical analysis and fertilizer recommendation. The study was able to separate the source of N from applied fertilizer and from the soils, traced using 15N during the 30 days after planting (DAP), 60 DAP and at harvest. Result show that, more than half of N in the plant came directly from added fertilizer during the early stage, which decreased towards harvest period. Fertilizer N yield use efficiency showed negative relationship with the rate of N application and soil fertility levels. Of N fertilization in different soil fertility levels were also established using isotope tracer technique. (author)

Resiliency and medicine: how to create a positive energy balance.

Science.gov (United States)

Kelly, John D

2011-01-01

A career in orthopaedics is a race-a marathon. Many outside forces converge to increase stressors to high levels. Resiliency, or the ability to bounce back from difficulty, can be learned and nurtured. The management of energy, rather than time, holds the key to avoiding burnout. Orthopaedic surgeons must minimize "energy drain" by first recognizing their ability to become proactive and control their lives. Surgeons must learn how to say "no" and delegate work and responsibilities. A positive energy balance can be attained when relationships, not things, are given priority. A focus on passions and inspiration helps to maintain energy, while a connection to a "source" and living a morally just, service-oriented life will yield endless energy.

A metabolic nitrogen balance study for 40 d and evaluation of the menstrual cycle on protein requirement in young Nigerian women.

Science.gov (United States)

Egun, G N; Atinmo, T

1993-09-01

A long-term N balance study was carried out to determine the adequacy of an estimated protein requirement level recommended for young healthy Nigerian women and the effect of the menstrual cycle on the requirement. Eleven healthy young women, 25 (SD 2.6) years, were fed on a diet providing 0.6 g protein (N x 6.25)/kg per d and an average energy intake of 0.17 (SD 0.012) MJ/kg per d. Urine, faeces, sweat and menstrual fluids were collected for estimation of N balance. Menstrual N loss varied among individuals ranging from 46 to 124 mg N/d with an average of 89 (SD 21.8) mg N/d. Individual N balance was found to vary according to the day of the menstrual cycle. Positive N balances were recorded at about ovulation while negative balances were observed just before the onset of menstruation. The average N balance ranged from +8.49 (SD 5.64) to -430 (SD 7.84) mg N/kg per d. Nevertheless, an overall cumulative positive N balance of +5.7 (SD 6.98) mg N/kg per d which did not change significantly with time was observed for the last 5 d of two consecutive 20 d diet periods, although three subjects were in negative N balance. Blood biochemical measurements were stable except for one subject who had elevated serum aspartate aminotransferase (EC 2.6.1.1) levels. These findings suggest that our estimate of protein requirements was sufficient to achieve N balance equilibrium in a majority (70%) of young women. However, to satisfy 97.5% of the population, slight adjustments might be necessary in the energy intake since subjects who were in cumulative negative N balance also lost weight.

A review of carbon and nitrogen balances in switchgrass grown for energy

International Nuclear Information System (INIS)

Bransby, D.I.; McLaughlin, S.B.; Parrish, D.J.

1998-01-01

Increased atmospheric CO 2 caused partly by burning fossil fuels, is assumed to elevate the risk of global warming, while nitrate contamination of surface runoff and groundwater from fertilizer and agricultural wastes constitutes a serious environmental hazard on a regional scale. Switchgrass (Panicum virgatum L.) grown as an energy crop could reduce atmospheric CO 2 accumulation by replacing fossil fuels and sequestering C. It could also improve soil productivity by C sequestration, and reduce NO 3 -1 contamination of water by absorbing N lost from fertilizer and agricultural waste if planted in filter strips on adjacent land. The objective of this study was to assess potential impacts of switchgrass on C and N balances by reviewing and synthesizing information from current literature, unpublished data and on-going research. Replacing fossil fuels with switchgrass, or any other biomass, will have a much greater effect on atmospheric CO 2 than C sequestration. This is because replacing fossil fuels provides a cumulative effect, while C sequestration offers only a one-time benefit. Furthermore, switchgrass will provide net gains in C sequestration only if it replaces annual row crops, but not if it replaces grazed pasture. Nitrogen recovery by switchgrass in an Alabama study was 65.6%, which compares favorably with the 50% recovery frequently quoted as the norm for wheat (Triticum aestivum L.) and corn (Zea mays L.). (Author)

Sex differences in amino acids lost via sweating could lead to differential susceptibilities to disturbances in nitrogen balance and collagen turnover.

Science.gov (United States)

Dunstan, R H; Sparkes, D L; Dascombe, B J; Stevens, C J; Murphy, G R; Macdonald, M M; Gottfries, J; Gottfries, C-G; Roberts, T K

2017-08-01

Fluid collected during sweating is enriched with amino acids derived from the skin's natural moisturising factors and has been termed "faux" sweat. Little is known about sex differences in sweat amino acid composition or whether faux sweat amino acid losses affect nitrogen balance. Faux sweat collected by healthy adults (n = 47) after exercise, and at rest by chronic fatigue patients, was analysed for amino acid composition. Healthy females had higher total amino acid concentrations in sweat (10.5 ± 1.2 mM) compared with healthy males (6.9 ± 0.9 mM). Females had higher levels of 13 amino acids in sweat including serine, alanine and glycine. Higher hydroxyproline and proline levels suggested greater collagen turnover in females. Modelling indicated that with conservative levels of exercise, amino acid losses in females via faux sweat were triple than those predicted for urine, whereas in males they were double. It was concluded that females were more susceptible to key amino acid loss during exercise and/or hot conditions. Females reporting chronic fatigue had higher levels of methionine in faux sweat than healthy females. Males reporting chronic fatigue had higher levels of numerous amino acids in faux sweat compared to healthy males. Higher amino acid loss in faux sweat associated with chronic fatigue could contribute to a hypometabolic state. Depending on activity levels, climatic conditions and gender, amino acid losses in sweat and skin leachate could influence daily protein turnover where periods of continuously high turnover could lead to a negative net nitrogen balance.

Nitrogen balance for a plantation forest drainage canal on the North Carolina Coastal Plain

Science.gov (United States)

Timothy W. Appelboom; George M. Chescheir; R. Wayne Skaggs; J. Wendell Gilliam; Devendra M. Amatya

2009-01-01

Human alteration of the nitrogen cycle has led to increased riverine nitrogen loads, contributing to the eutrophication of lakes, streams, estuaries, and near-coastal oceans. These riverine nitrogen loads are usually less...

Nitrogen critical loads using biodiversity-related critical limits

International Nuclear Information System (INIS)

Posch, Maximilian; Aherne, Julian; Hettelingh, Jean-Paul

2011-01-01

Critical loads are widely used in the effects-based assessment of emission reduction policies. While the impacts of acidification have diminished, there is increasing concern regarding the effects of nitrogen deposition on terrestrial ecosystems. In this context much attention has been focussed on empirical critical loads as well as simulations with linked geochemistry-vegetation models. Surprisingly little attention has been paid to adapt the widely used simple mass balance approach. This approach has the well-established benefit of easy regional applicability, while incorporating specified critical chemical criteria to protect specified receptors. As plant occurrence/biodiversity is related to both the nutrient and acidity status of an ecosystem, a single abiotic factor (chemical criterion) is not sufficient. Rather than an upper limit for deposition (i.e., critical load), linked nutrient nitrogen and acidity chemical criteria for plant occurrence result in an 'optimal' nitrogen and sulphur deposition envelope. - Highlights: → Mass balance critical load approaches for nutrient nitrogen remain useful. → Biodiversity-related limits are related to nutrient and acidity status. → Nutrient and acidity chemical criteria lead to optimal deposition envelopes. → Optimal loads support effects-based emission reduction policies. - Biodiversity-related critical limits lead to optimal nitrogen and sulphur deposition envelopes for plant species or species compositions.

Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion

Science.gov (United States)

Mitch, William E.; Sands, Jeff M.

2015-01-01

Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance. PMID:25078422

Comparison of surface mass balance of ice sheets simulated by positive-degree-day method and energy balance approach

Directory of Open Access Journals (Sweden)

E. Bauer

2017-07-01

Full Text Available Glacial cycles of the late Quaternary are controlled by the asymmetrically varying mass balance of continental ice sheets in the Northern Hemisphere. Surface mass balance is governed by processes of ablation and accumulation. Here two ablation schemes, the positive-degree-day (PDD method and the surface energy balance (SEB approach, are compared in transient simulations of the last glacial cycle with the Earth system model of intermediate complexity CLIMBER-2. The standard version of the CLIMBER-2 model incorporates the SEB approach and simulates ice volume variations in reasonable agreement with paleoclimate reconstructions during the entire last glacial cycle. Using results from the standard CLIMBER-2 model version, we simulated ablation with the PDD method in offline mode by applying different combinations of three empirical parameters of the PDD scheme. We found that none of the parameter combinations allow us to simulate a surface mass balance of the American and European ice sheets that is similar to that obtained with the standard SEB method. The use of constant values for the empirical PDD parameters led either to too much ablation during the first phase of the last glacial cycle or too little ablation during the final phase. We then substituted the standard SEB scheme in CLIMBER-2 with the PDD scheme and performed a suite of fully interactive (online simulations of the last glacial cycle with different combinations of PDD parameters. The results of these simulations confirmed the results of the offline simulations: no combination of PDD parameters realistically simulates the evolution of the ice sheets during the entire glacial cycle. The use of constant parameter values in the online simulations leads either to a buildup of too much ice volume at the end of glacial cycle or too little ice volume at the beginning. Even when the model correctly simulates global ice volume at the last glacial maximum (21 ka, it is unable to simulate

Mass balance, meteorology, area altitude distribution, glacier-surface altitude, ice motion, terminus position, and runoff at Gulkana Glacier, Alaska, 1996 balance year

Science.gov (United States)

March, Rod S.

2003-01-01

The 1996 measured winter snow, maximum winter snow, net, and annual balances in the Gulkana Glacier Basin were evaluated on the basis of meteorological, hydrological, and glaciological data. Averaged over the glacier, the measured winter snow balance was 0.87 meter on April 18, 1996, 1.1 standard deviation below the long-term average; the maximum winter snow balance, 1.06 meters, was reached on May 28, 1996; and the net balance (from August 30, 1995, to August 24, 1996) was -0.53 meter, 0.53 standard deviation below the long-term average. The annual balance (October 1, 1995, to September 30, 1996) was -0.37 meter. Area-averaged balances were reported using both the 1967 and 1993 area altitude distributions (the numbers previously given in this abstract use the 1993 area altitude distribution). Net balance was about 25 percent less negative using the 1993 area altitude distribution than the 1967 distribution. Annual average air temperature was 0.9 degree Celsius warmer than that recorded with the analog sensor used since 1966. Total precipitation catch for the year was 0.78 meter, 0.8 standard deviations below normal. The annual average wind speed was 3.5 meters per second in the first year of measuring wind speed. Annual runoff averaged 1.50 meters over the basin, 1.0 standard deviation below the long-term average. Glacier-surface altitude and ice-motion changes measured at three index sites document seasonal ice-speed and glacier-thickness changes. Both showed a continuation of a slowing and thinning trend present in the 1990s. The glacier terminus and lower ablation area were defined for 1996 with a handheld Global Positioning System survey of 126 locations spread out over about 4 kilometers on the lower glacier margin. From 1949 to 1996, the terminus retreated about 1,650 meters for an average retreat rate of 35 meters per year.

Ostertagia ostertagi in calves: growth, nitrogen balance and digestibility studies conducted during winter feeding following different fenbendazole therapy programmes.

Science.gov (United States)

Parkins, J J; Bairden, K; Armour, J

1982-01-01

Observations of growth, nitrogen (N) balance and digestibility were made during the first winter housing period upon three groups of calves which had previously been naturally infected with Ostertagia ostertagi and which were left either untreated (A) or treated with fenbendazole on three occasions (B) or every two weeks during the entire grazing season (C). The diet given contained sufficient metabolisable energy but only about 60 per cent of the recommended crude protein to sustain a daily growth rate of 0.5 kg. Growth rates were only 50 per cent of that expected on a basis of metabolisable energy input with untreated calves A being poorest. Water intake and output was greatest in group A. There were no significant differences in digestibility between groups although group A had the lowest apparent crude protein digestibility. N balance was always lowest in group A and highest in group C but group B demonstrated a marked increase in N retention with time after housing. Differences in N retention were mainly accounted for by increased urinary N excretion. It is concluded that, under conditions of suboptimal protein intake, nematode infection in the growing calf can markedly affect production even after efficient anthelmintic treatment.

Effects of ruminally degradable starch levels on performance, nitrogen balance, and nutrient digestibility in dairy cows fed low corn-based starch diets

Directory of Open Access Journals (Sweden)

Guobin Luo

2017-05-01

Full Text Available Objective This trial was performed to examine the effects of ruminally degradable starch (RDS levels in total mixed ration (TMR with low corn-based starch on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows. Methods Eight multiparous Holstein cows (body weight [BW]: 717±63 kg; days in milk [DIM]: 169±29 were assigned to a crossover design with two dietary treatments: a diet containing 62.3% ruminally degradable starch (% of total starch, low RDS or 72.1% ruminally degradable starch (% of total starch, high RDS. Changes to the ruminally degradable levels were conducted by using either finely ground corn or steam-flaked corn as the starch component. Results The results showed that dry matter intake, milk yield and composition in dairy cows were not affected by dietary treatments. The concentration of milk urea nitrogen was lower for cows fed high RDS TMR than low RDS TMR. The whole-tract apparent digestibility of neutral detergent fiber, acid detergent fiber and crude protein decreased, and that of starch increased for cows fed high RDS TMR over those fed low RDS TMR, with no dietary effect on the whole-tract apparent digestibility of dry matter and organic matter. The proportion of urinary N excretion in N intake was lower and that of fecal N excretion in N intake was higher for cows fed high RDS TMR than those fed low RDS TMR. The N secretion in milk and the retention of N were not influenced by the dietary treatments. Total purine derivative was similar in cows fed high RDS TMR and low RDS TMR. Consequently, estimated microbial N flow to the duodenum was similar in cows fed high RDS TMR and low RDS TMR. Conclusion Results of this study show that ruminally degradable starch levels can influence whole-tract nutrient digestibility and nitrogen balance in dairy cows fed low corn-based starch diets, with no influence on performance.

Nitrogen balance study in young Nigerian adult males using four levels of protein intake.

Science.gov (United States)

Atinmo, T; Mbofung, C M; Egun, G; Osotimehin, B

1988-11-01

1. The present study was carried out to estimate precisely, via the nitrogen balance technique, the protein requirement of Nigerians (earlier estimated via the obligatory N method) using graded levels of protein intake. 2. Fifteen medical students of the University of Ibadan who volunteered to participate in the study were given graded levels of protein (0.3, 0.45, 0.6 and 0.75 g/kg body-weight per d) derived from foods similar to those usually consumed by the subjects. 3. Each subject was given each of the dietary protein levels for a period of 10 d. Subjects were divided into two groups and the feeding pattern followed a criss-cross design with one group starting with the highest level of protein intake (0.3 g). Mean energy intake during each of the eleven experimental periods was maintained at 0.2 MJ/kg per d. After an initial 5 d adaptation period in each experimental period, 24 h urine and faecal samples were collected in marked containers for five consecutive days for N determination. 4. Mean N balance during consumption of the four protein levels (0.30, 0.45, 0.6 and 0.75 g/kg) were -11.02 (SD 8.07), -9.90 (SD 6.64), +9.70 (SD 4.15) and +5.13 (SD 4.62) respectively. Using regression analysis, the mean daily N requirement was estimated at 110.25 mg N/kg body-weight (0.69 g protein/kg body-weight). Estimates of allowances for individual variations to cover 97.5% of the population adjusted this value to 0.75 g protein/kg body-weight. Net protein utilization for the diet at maintenance level was estimated at 57.5.

Effects of capsaicin, green tea and CH-19 sweet pepper on appetite and energy intake in humans in negative and positive energy balance

DEFF Research Database (Denmark)

Reinbach, Helene Christine; Smeets, A.; Martinussen, Torben

2009-01-01

Summary Background & aims Bioactive ingredients have been shown to reduce appetite and energy intake. The magnitude of these effects might depend on energy balance why it was investigated how capsaicin, green tea, CH-19 sweet pepper as well as green tea and capsaicin affect appetite and energy...... intake during respectively negative and positive energy balance. Methods 27 subjects were randomized to three weeks of negative and three weeks of positive energy balance during which capsaicin, green tea, CH-19 sweet pepper, capsaicin + green tea or placebo was ingested on ten separate test days while...... the effects on appetite, energy intake, body weight and heart rate were assessed. Results CH-19 sweet pepper and a combination of capsaicin and green tea reduced energy intake during positive energy balance. Capsaicin and green tea suppressed hunger and increased satiety more during negative than during...

Mandibular position influence on pilots' postural balance analyzed under dynamic conditions.

Science.gov (United States)

Baldini, Alberto; Nota, Alessandro; Cioffi, Clementina; Ballanti, Fabiana; Tecco, Simona

2017-11-01

The aim of this study is to evaluate the influence of the mandibular position on the postural stability in a sample of civilian and military pilots. Twenty military pilots (males, mean age 35.15 ± 3.14 years) and 17 civilian pilots (males, mean 34.91 ± 2.15 years) were enrolled in this study and underwent a Sensory Organization Test (SOT) using the EquiTest® (NeuroCom International Inc., Clackamas, OR, USA) computerized dynamic posturography. The composite parameter was recorded and analyzed. The equilibrium score (ES) recorded in centric occlusion is slightly higher than the ES recorded in mandibular rest position; civilian pilots showed ESs slightly higher than military pilots. The two-way ANOVA analysis shows these differences are not statistically significant. The findings of this study seem to suggest that the composite parameter of the SOT is not sensitive in analyzing the influence of the stomatognathic system on the postural balance of civilian and military pilots.

[Characteristic of ammonia nitrogen adsorption on karst underground river sediments].

Science.gov (United States)

Guo, Fang; Chen, Kun-Kun; Jiang, Guang-Hui

2011-02-01

Karst aquifers are one of the most important aquifers in Southwestern China. One of the characteristics of karst aquifers is the enhanced permeability permits high flow velocities are capable of transporting suspended and bedload sediments. Mobile sediment in karst may act as a vector for the transport of contaminates. 14 sediment samples were collected from two underground rivers in two typical karst areas in Liuzhou city, Guangxi Autonomous Region, China. According to simulated experiment methods, characteristic of adsorption of ammonia nitrogen on sediment was studied. The results of ammonia nitrogen adsorption dynamics on sediments showed that the maximum adsorption velocity was less than 2 h. The adsorption balance quantity in 5 h accounted for 71% - 98% of the maximum adsorption quantity. The maximum adsorption quantity of ammonia nitrogen was 385.5 mg/kg, which was sediment from a cave in the middle areas of Guancun underground river system. The study of isotherm adsorption indicated adsorption quantity of NH4+ increase followed by incremental balance concentration of NH4+ in the aquatic phase. Adsorption quantity of ammonia nitrogen in sediments has a relative linear relationship with adsorption balance concentrations. Adsorption-desorption balance concentrations were all low, indicating sediments from underground rivers have great adsorption potential. Under the condition of low and high concentrations of ammonia nitrogen in overlying water, Langmuir and Tempkin couldn't simulate or simulate results couldn't reach remarkable level, whilst Linear and Freundlich models could simulate well. Research on different type sediments, sampling times and depths from two underground rivers shows characteristic of ammonia nitrogen adsorption on karst underground river sediments doesn't have good correspondence with the type of sediments. One of the reasons is there is no big difference between sediments in the development of climate, geology, hydrological conditions

The effects of different nitrogen doses on yield, quality and leaf ...

African Journals Online (AJOL)

Nitrogen deficiency is a worldwide problem, causing restrictions in productivity of many horticultural produces. Particularly, the issue is compounded when the greenhouse production is employed. Therefore, reliable knowledge on proper application of nitrogen ensures not only satisfactory yield but also balanced vegetative ...

Effects of balance Vestibular Rehabilitation Therapy in elderly with Benign Paroxysmal Positional Vertigo: a randomized controlled trial.

Science.gov (United States)

Ribeiro, Karyna Myrelly Oliveira Bezerra de Figueiredo; Freitas, Raysa Vanessa de Medeiros; Ferreira, Lidiane Maria de Brito Macedo; Deshpande, Nandini; Guerra, Ricardo Oliveira

2017-06-01

To evaluate short-term effects of balance Vestibular Rehabilitation Therapy (VRT) on balance, dizziness symptoms and quality of life of the elderly with chronic Benign Paroxysmal Positional Vertigo (BPPV). In this randomized, single-blind and controlled trial, older adults with chronic BPPV were randomized into two groups, the experimental group (n = 7, age: 69 (65-78) years) and the control group (n = 7, age: 73 (65-76) years). Patients in the experimental group underwent balance VRT (50 min per session, two times a week) and Canalith Repositioning Maneuver (CRM) as required, for 13 weeks. The control group was treated using only CRM as required. Standing and dynamic balance, dizziness symptoms and quality of life were measured at the baseline, and at one, five, nine and thirteen weeks. There were no between-group differences in dizziness, quality of life and standing balance over the 13 weeks. Significant differences were observed in dynamic balance measures between groups (p CRM. Implications for Rehabilitation The findings that balance VRT in addition to CRM improves dynamic balance in elderly people with BPPV should be useful in guiding rehabilitation professionals' clinical decision making to design interventions for seniors suffering from BPPV; Improvements in tests of dynamic balance suggest that the risk of adverse consequences of BPPV in the elderly such as falls and fractures can be potentially reduced through implementation of CRM in conjunction with balance VRT; Lack of additional improvement in Visual Analogue Scale of dizziness and Dizziness Handicap Index suggests that addition of balance VRT does not influence dizziness symptomatology, per se, and CRM alone is effective to ameliorate vertiginous symptoms and potentially improve quality of life.

High angle of attack position sensing for the Southampton University magnetic suspension and balance system

Science.gov (United States)

Parker, David H.

1987-01-01

An all digital five channel position detection system is to be installed in the Southampton University Magnetic Suspension and Balance System (SUMSBS). The system is intended to monitor a much larger range of model pitch attitudes than has been possible hitherto, up to a maximum of a 90 degree angle of attack. It is based on the use of self-scanning photodiode arrays and illuminating laser light beams, together with purpose built processing electronics. The principles behind the design of the system are discussed, together with the results of testing one channel of the system which was used to control the axial position of a magnetically suspended model in SUMSBS. The removal of optically coupled heave position information from the axial position sensing channel is described.

Fertilizer nitrogen fixation in plants and its transmutation in soils in case of annual application

International Nuclear Information System (INIS)

Shilova, E.I.; Smirnov, P.M.; Khon, N.I.

1974-01-01

Using certain combinations of 15 N labeled and unlabeled nitrogen-containing fertilizers data were obtained for direct determination of nitrogen balance in the year of fertilization and subsequently. Annual and total (for 3 years) increment in utilization of soil nitrogen resulting from repeated fertilization was also determined. Coefficient of nitrogen utilization by barley decreased over the 3-year period after additional application of ammonium sulfate while biological immobilization of nitrogen tended to increase. Application of straw during the first year of the experiment did not significantly affect the nitrogen balance in the following years. The total coefficient of nitrogen utilization for the 2 to 3-year period was higher than that of the first year while biological immobilization was relatively lower. Additional utilization of soil nitrogen as compared to the control was the same over the whole 3-year period; additional mobilization (annual and total) was relatively higher due to lower removal of soil nitrogen in the subsequent years. Utilization of previously immobilized nitrogen was higher in the case of repeated fertilization than without application of nitrogen fertilizers. The content of newly immobilized nitrogen during 3 years in the hydrolyzable undistilable fraction (nitrogen of bounded amino acids) was relatively lower and this was accompanied by the growth of hydrolyzable distilable and unhydrolyzable nitrogen

Effect of water and nitrogen additions on free-living nitrogen fixer populations in desert grass root zones.

Science.gov (United States)

Herman, R P; Provencio, K R; Torrez, R J; Seager, G M

1993-01-01

In this study we measured changes in population levels of free-living N2-fixing bacteria in the root zones of potted Bouteloua eriopoda and Sporobolus flexuosus plants as well as the photosynthetic indices of the plants in response to added nitrogen, added water, and added water plus nitrogen treatments. In addition, N2 fixer population changes in response to added carbon source and nitrogen were measured in plant-free soil columns. There were significant increases in the numbers of N2 fixers associated with both plant species in the water and the water plus nitrogen treatments. Both treatments increased the photosynthetic index, suggesting that plant exudates were driving N2 fixer population changes. Population increases were greatest in the water plus nitrogen treatments, indicating that added nitrogen was synergistic with added water and suggesting that nitrogen addition spared bacteria the metabolic cost of N2 fixation, allowing greater reproduction. Plant-free column studies demonstrated a synergistic carbon-nitrogen effect when carbon levels were limiting (low malate addition) but not when carbon was abundant (high malate), further supporting this hypothesis. The results of this study indicate the presence of N2 fixer populations which interact with plants and which may play a role in the nitrogen balance of desert grasslands. PMID:8215373

Determination of the Optimal Position of Pendulums of an Active Self-balancing Device

OpenAIRE

Ziyakaev, Gregory Rakitovich; Kazakova, Oksana Aleksandrovna; Yankov, V. V.; Ivkina, O. P.

2017-01-01

The demand of the modern manufacturing industry for machines with high motion speed leads to increased load and vibration activity of the main elements of rotor systems. Vibration reduces operating life of bearings, has adversary effects on human organism, and can cause accidents. One way to compensate for a rotating rotor's imbalance is the use of active self-balancing devices. The aim of this work is to determine the position of their pendulums, in which the imbalance is minimized. As a res...

Studies on supplementary desalted mother liquor on digestibility of nutrients, ruminal fermentation, and energy and nitrogen balance in Thai native cattle.

Science.gov (United States)

Sakai, Takashi; Angthong, Wanna; Takeda, Motoharu; Oishi, Kazato; Hirooka, Hiroyuki; Kumagai, Hajime

2017-09-01

Four Thai native steers were used to determine the adequate levels of supplementary desalted mother liquor (DML) for energy and nitrogen balances and ruminal fermentation. The crude protein and sodium chloride contents of DML were 25.5% and 60.3% on a dry matter (DM) basis, respectively. A 4 × 4 Latin square design experiment was conducted by adding different amounts of DML to three experimental diets (T1: 1.1%, T2: 2.2%, T3: 3.4% sodium chloride concentration with supplementary DML on a DM basis) and comparing their effects with those of a control diet (C) containing 1.0% commercial salt on a DM basis. The animals were given the experimental diets and rice straw daily at 1.2% and 0.8% of body weight, respectively, on a DM basis. No significant differences in the apparent digestibility of nutrients were observed among treatments. T3 achieved the lowest nitrogen retention (P < 0.05), followed by C, T2 and T1. The ratios of energy retention to gross energy were higher in T1 and T3 than T2, and that in C was lowest (P < 0.05). Supplementary NaCl concentration at 1% and 2% can be replaced with DML without an adverse effect on the digestibility of nutrients or on the nitrogen and energy retention. © 2017 Japanese Society of Animal Science.

PLASMA PROTEIN AND HEMOGLOBIN PRODUCTION : DELETION OF INDIVIDUAL AMINO ACIDS FROM GROWTH MIXTURE OF TEN ESSENTIAL AMINO ACIDS. SIGNIFICANT CHANGES IN URINARY NITROGEN.

Science.gov (United States)

Robscheit-Robbins, F S; Miller, L L; Whipple, G H

1947-02-28

Given healthy dogs fed abundant iron and protein-free or low protein diets with sustained anemia and hypoproteinemia, we can study the capacity of these animals to produce simultaneously new hemoglobin and plasma protein. Reserve stores of blood protein-building materials are measurably depleted and levels of 6 to 8 gm. per cent for hemoglobin and 4 to 5 gm. per cent for plasma protein can be maintained for weeks or months depending upon the intake of food proteins or amino acid mixtures. These dogs are very susceptible to infection and various poisons. Dogs tire of these diets and loss of appetite terminates many experiments. Under these conditions (double depletion) standard growth mixtures of essential amino acids are tested to show the response in blood protein output and urinary nitrogen balance. As a part of each tabulated experiment one of the essential amino acids is deleted from the complete growth mixture to compare such response with that of the whole mixture. Methionine, threonine, phenylalanine, and tryptophane when singly eliminated from the complete amino acid mixture do effect a sharp rise in urinary nitrogen. This loss of urinary nitrogen is corrected when the individual amino acid is replaced in the mixture. Histidine, lysine, and valine have a moderate influence upon urinary nitrogen balance toward nitrogen conservation. Leucine, isoleucine, and arginine have minimal or no effect upon urinary nitrogen balance when these individual amino acids are deleted from the complete growth mixture of amino acids during 3 to 4 week periods. Tryptophane and to a less extent phenylalanine and threonine when returned to the amino acid mixture are associated with a conspicuous preponderance of plasma protein output over the hemoglobin output (Table 4). Arginine, lysine, and histidine when returned to the amino acid mixture are associated with a large preponderance of hemoglobin output. Various amino acid mixtures under these conditions may give a positive

Interactions between nitrogen deposition, land cover conversion, and climate change determine the contemporary carbon balance of Europe

Directory of Open Access Journals (Sweden)

G. Churkina

2010-09-01

Full Text Available European ecosystems are thought to take up large amounts of carbon, but neither the rate nor the contributions of the underlying processes are well known. In the second half of the 20th century, carbon dioxide concentrations have risen by more that 100 ppm, atmospheric nitrogen deposition has more than doubled, and European mean temperatures were increasing by 0.02 °C yr⁻¹. The extents of forest and grasslands have increased with the respective rates of 5800 km² yr⁻¹ and 1100 km² yr⁻¹ as agricultural land has been abandoned at a rate of 7000 km² yr⁻¹. In this study, we analyze the responses of European land ecosystems to the aforementioned environmental changes using results from four process-based ecosystem models: BIOME-BGC, JULES, ORCHIDEE, and O-CN. The models suggest that European ecosystems sequester carbon at a rate of 56 TgC yr⁻¹ (mean of four models for 1951–2000 with strong interannual variability (±88 TgC yr⁻¹, average across models and substantial inter-model uncertainty (±39 TgC yr⁻¹. Decadal budgets suggest that there has been a continuous increase in the mean net carbon storage of ecosystems from 85 TgC yr⁻¹ in 1980s to 108 TgC yr⁻¹ in 1990s, and to 114 TgC yr⁻¹ in 2000–2007. The physiological effect of rising CO₂ in combination with nitrogen deposition and forest re-growth have been identified as the important explanatory factors for this net carbon storage. Changes in the growth of woody vegetation are suggested as an important contributor to the European carbon sink. Simulated ecosystem responses were more consistent for the two models accounting for terrestrial carbon-nitrogen dynamics than for the two models which only accounted for carbon cycling and the effects of land cover change. Studies of the interactions of carbon-nitrogen dynamics with

The evolution and future of Earth's nitrogen cycle.

Science.gov (United States)

Canfield, Donald E; Glazer, Alexander N; Falkowski, Paul G

2010-10-08

Atmospheric reactions and slow geological processes controlled Earth's earliest nitrogen cycle, and by ~2.7 billion years ago, a linked suite of microbial processes evolved to form the modern nitrogen cycle with robust natural feedbacks and controls. Over the past century, however, the development of new agricultural practices to satisfy a growing global demand for food has drastically disrupted the nitrogen cycle. This has led to extensive eutrophication of fresh waters and coastal zones as well as increased inventories of the potent greenhouse gas nitrous oxide (N(2)O). Microbial processes will ultimately restore balance to the nitrogen cycle, but the damage done by humans to the nitrogen economy of the planet will persist for decades, possibly centuries, if active intervention and careful management strategies are not initiated.

The Evolution and Future of Earth's Nitrogen Cycle

DEFF Research Database (Denmark)

Canfield, Donald Eugene; Glazer, Alexander N.; Falkowski, Paul G.

2010-01-01

, the development of new agricultural practices to satisfy a growing global demand for food has drastically disrupted the nitrogen cycle. This has led to extensive eutrophication of fresh waters and coastal zones as well as increased inventories of the potent greenhouse gas nitrous oxide (N2O). Microbial processes......Atmospheric reactions and slow geological processes controlled Earth's earliest nitrogen cycle, and by similar to 2.7 billion years ago, a linked suite of microbial processes evolved to form the modern nitrogen cycle with robust natural feedbacks and controls. Over the past century, however...... will ultimately restore balance to the nitrogen cycle, but the damage done by humans to the nitrogen economy of the planet will persist for decades, possibly centuries, if active intervention and careful management strategies are not initiated....

Reducing equifinality using isotopes in a process-based stream nitrogen model highlights the flux of algal nitrogen from agricultural streams

Science.gov (United States)

Ford, William I.; Fox, James F.; Pollock, Erik

2017-08-01

The fate of bioavailable nitrogen species transported through agricultural landscapes remains highly uncertain given complexities of measuring fluxes impacting the fluvial N cycle. We present and test a new numerical model named Technology for Removable Annual Nitrogen in Streams For Ecosystem Restoration (TRANSFER), which aims to reduce model uncertainty due to erroneous parameterization, i.e., equifinality, in stream nitrogen cycle assessment and quantify the significance of transient and permanent removal pathways. TRANSFER couples nitrogen elemental and stable isotope mass-balance equations with existing hydrologic, hydraulic, sediment transport, algal biomass, and sediment organic matter mass-balance subroutines and a robust GLUE-like uncertainty analysis. We test the model in an agriculturally impacted, third-order stream reach located in the Bluegrass Region of Central Kentucky. Results of the multiobjective model evaluation for the model application highlight the ability of sediment nitrogen fingerprints including elemental concentrations and stable N isotope signatures to reduce equifinality of the stream N model. Advancements in the numerical simulations allow for illumination of the significance of algal sloughing fluxes for the first time in relation to denitrification. Broadly, model estimates suggest that denitrification is slightly greater than algal N sloughing (10.7% and 6.3% of dissolved N load on average), highlighting the potential for overestimation of denitrification by 37%. We highlight the significance of the transient N pool given the potential for the N store to be regenerated to the water column in downstream reaches, leading to harmful and nuisance algal bloom development.

Farm nitrogen balances in six European landscapes as an indicator for nitrogen losses and basis for improved management

Science.gov (United States)

Dalgaard, T.; Bienkowski, J. F.; Bleeker, A.; Dragosits, U.; Drouet, J. L.; Durand, P.; Frumau, A.; Hutchings, N. J.; Kedziora, A.; Magliulo, V.; Olesen, J. E.; Theobald, M. R.; Maury, O.; Akkal, N.; Cellier, P.

2012-12-01

Improved management of nitrogen (N) in agriculture is necessary to achieve a sustainable balance between the production of food and other biomass, and the unwanted effects of N on water pollution, greenhouse gas emissions, biodiversity deterioration and human health. To analyse farm N-losses and the complex interactions within farming systems, efficient methods for identifying emissions hotspots and evaluating mitigation measures are therefore needed. The present paper aims to fill this gap at the farm and landscape scales. Six agricultural landscapes in Poland (PL), the Netherlands (NL), France (FR), Italy (IT), Scotland (UK) and Denmark (DK) were studied, and a common method was developed for undertaking farm inventories and the derivation of farm N balances, N surpluses and for evaluating uncertainty for the 222 farms and 11 440 ha of farmland included in the study. In all landscapes, a large variation in the farm N surplus was found, and thereby a large potential for reductions. The highest average N surpluses were found in the most livestock-intensive landscapes of IT, FR, and NL; on average 202 ± 28, 179 ± 63 and 178 ± 20 kg N ha-1 yr-1, respectively. All landscapes showed hotspots, especially from livestock farms, including a special UK case with large-scale landless poultry farming. Overall, the average N surplus from the land-based UK farms dominated by extensive sheep and cattle grazing was only 31 ± 10 kg N ha-1 yr-1, but was similar to the N surplus of PL and DK (122 ± 20 and 146 ± 55 kg N ha-1 yr-1, respectively) when landless poultry farming was included. We found farm N balances to be a useful indicator for N losses and the potential for improving N management. Significant correlations to N surplus were found, both with ammonia air concentrations and nitrate concentrations in soils and groundwater, measured during the period of N management data collection in the landscapes from 2007-2009. This indicates that farm N surpluses may be used as an

Background information on a multimedia nitrogen emission reduction strategy; Hintergrundpapier zu einer multimedialen Stickstoffemissionsminderungsstrategie

Energy Technology Data Exchange (ETDEWEB)

Geupel; Jering; Frey (and others)

2009-04-15

The background information report on a multimedia nitrogen reduction strategy covers the following chapters: 1. Introduction: the nitrogen cascade and the anthropogenic influence, environmental impact of increased nitrogen emissions and effects on human health. 2. Sources and balancing of anthropogenic nitrogen emissions in Germany. 3. Environmental quality targets, activity goals of environmental measures and instruments of an integrated nitrogen reduction strategy. 4. Conclusions and perspectives. The attachments include emission sources, nitrogen release and nitrogen transport in Germany; catalogue of measures and instruments according the criteria efficiency and cost-efficacy.

Diet density during the first week of life: Effects on energy and nitrogen balance characteristics of broiler chickens.

Science.gov (United States)

Lamot, D M; Sapkota, D; Wijtten, P J A; van den Anker, I; Heetkamp, M J W; Kemp, B; van den Brand, H

2017-07-01

This study aimed to determine effects of diet density on growth performance, energy balance, and nitrogen (N) balance characteristics of broiler chickens during the first wk of life. Effects of diet density were studied using a dose-response design consisting of 5 dietary fat levels (3.5, 7.0, 10.5, 14.0, and 17.5%). The relative difference in dietary energy level was used to increase amino acid levels, mineral levels, and the premix inclusion level at the same ratio. Chickens were housed in open-circuit climate respiration chambers from d 0 to 7 after hatch. Body weight was measured on d 0 and 7, whereas feed intake was determined daily. For calculation of energy balances, O2 and CO2 exchange were measured continuously and all excreta from d 0 to 7 was collected and analyzed at d 7. Average daily gain (ADG) and average daily feed intake (ADFI) decreased linearly (P = 0.047 and P density. Gross energy (GE) intake and metabolizable energy (ME) intake were not affected by diet density, but the ratio between ME and GE intake decreased linearly with increasing diet density (P = 0.006). Fat, N, and GE efficiencies (expressed as gain per unit of nutrient intake), heat production, and respiratory exchange ratio (CO2 to O2 ratio) decreased linearly (P density increased. Energy retention, N intake, and N retention were not affected by diet density. We conclude that a higher diet density in the first wk of life of broiler chickens did not affect protein and fat retention, whereas the ME to GE ratio decreased linearly with increased diet density. This suggests that diet density appears to affect digestibility rather than utilization of nutrients. © 2017 Poultry Science Association Inc.

Positive curvature effects and interparticle capillary condensation during nitrogen adsorption in particulate porous materials.

Science.gov (United States)

Gommes, Cedric J; Ravikovitch, Peter; Neimark, Alexander

2007-10-15

The adsorption of nitrogen in a collection of spheres that touch or merge in a sintering-like manner is modeled using a Derjaguin-Broeckhof-de Boer approach. The proposed model accounts for both positive curvature effects and for capillary condensation at the contact between two spheres. A methodology is proposed to fit the P/P(0)>0.4 adsorption region with the coordination number of the spheres as the only adjustable parameter. The use of the model is illustrated on a series of silica aerogels. The suitability of various standard isotherms needed for the modeling is also discussed.

Cost-effectiveness of nitrogen mitigation by alternative household wastewater management technologies.

Science.gov (United States)

Wood, Alison; Blackhurst, Michael; Hawkins, Troy; Xue, Xiaobo; Ashbolt, Nicholas; Garland, Jay

2015-03-01

Household wastewater, especially from conventional septic systems, is a major contributor to nitrogen pollution. Alternative household wastewater management technologies provide similar sewerage management services but their life cycle costs and nitrogen flow implications remain uncertain. This paper addresses two key questions: (1) what are the total costs, nitrogen mitigation potential, and cost-effectiveness of a range of conventional and alternative municipal wastewater treatment technologies, and (2) what uncertainties influence these outcomes and how can we improve our understanding of these technologies? We estimate a household nitrogen mass balance for various household wastewater treatment systems and combine this mass balance with life cycle cost assessment to calculate the cost-effectiveness of nitrogen mitigation, which we define as nitrogen removed from the local watershed. We apply our methods to Falmouth, MA, where failing septic systems have caused heightened eutrophication in local receiving water bodies. We find that flushing and dry (composting) urine-diversion toilets paired with conventional septic systems for greywater management demonstrate the lowest life cycle cost and highest cost-effectiveness (dollars per kilogram of nitrogen removed from the watershed). Composting toilets are also attractive options in some cases, particularly best-case nitrogen mitigation. Innovative/advanced septic systems designed for high-level nitrogen removal are cost-competitive options for newly constructed homes, except at their most expensive. A centralized wastewater treatment plant is the most expensive and least cost-effective option in all cases. Using a greywater recycling system with any treatment technology increases the cost without adding any nitrogen removal benefits. Sensitivity analysis shows that these results are robust considering a range of cases and uncertainties. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Studies on nitrogen retention in growing pigs

DEFF Research Database (Denmark)

Thorbek, G; Henckel, S; Chwalibog, André

1987-01-01

Nitrogen retention (RN) was measured in 60 barrows of Danish Landrace and a total of 470 balance periods was carried out during the growth period from 20 to 85 kg live weight. In the first serie (Expt A) six different feed compounds of high biological value (HBV) were fed to 48 barrows, while...... in the second serie (Expt B) 12 barrows were measured on feed compounds of HBV or low biological value (LBV). Three different levels of gross energy were used in Expt B. Individual differences of 10-20% in the pigs capability for nitrogen retention were observed. Nitrogen retention increased from 12 to 21 g N....../d on the HBV-compounds and was not influenced by increasing nitrogen or energy intake. Nitrogen retention was curvilinear in relation to metabolic live weight (kg0.75) in both series. A parabolic function on kg0.75 gave the best fit to the data with the following regression equations: Expt A + B: RN, g/d = 1...

Vertical nitrogen flux from the oceanic photic zone by diel migrant zooplankton and nekton

Science.gov (United States)

Longhurst, Alan R.; Glen Harrison, W.

1988-06-01

Where the photic zone is a biological steady-state, the downward flux of organic material across the pycnocline to the interior of the ocean is thought to be balanced by upward turbulent flux of inorganic nitrogen across the nutricline. This model ignores a significant downward dissolved nitrogen flux caused by the diel vertical migration of interzonal zooplankton and nekton that feed in the photic zone at night and excrete nitrogenous compounds at depth by day. In the oligotrophic ocean this flux can be equivalent to the flux of particulate organic nitrogen from the photic zone in the form of faecal pellets and organic flocculates. Where nitrogen is the limiting plant nutrient, and the flux by diel migration of interzonal plankton is significant compared to other nitrogen exports from the photic zone, there must be an upward revision of previous estimates for the ratio of new to total primary production in the photic zone if a nutrient balance is to be maintained. This upward revision is of the order 5-100% depending on the oceanographic regime.

The influence of Pilates exercises on body balance in the standing position of hearing impaired people.

Science.gov (United States)

Walowska, Jagoda; Bolach, Bartosz; Bolach, Eugeniusz

2017-11-13

Hearing impairment may affect the body posture maintenance. The aim of the study was to evaluate the effect of modified Pilates exercise program on the body posture maintenance in hearing impaired people. Eighty students (aged 13-24) were enrolled and randomly allocated into two groups: test group (n = 41) which attended an original program based on modified Pilates exercises and control group (n = 39) which attended standard physical education classes. Stabilographic tests were conducted at baseline and after 6-week training program. Both groups showed improved control of body balance in a standing position manifested in reductions of the length of path, surface area, and speed of deflection. Modified Pilates program was significantly more effective in improving body balance control in relaxed posture and with feet together than standard physical education classes. The greater efficiency of the modified Pilates program was expressed in a significant improvement in balance control parameters, i.e., path length, surface area, and speed of deflection. The modified Pilates program was more effective in improving body balance control in the hearing impaired people than standard physical education classes. Modification of physical activity recommendations for hearing impaired students may be considered; however, further research is required. Implications for Rehabilitation Hearing impairment impacts the mental, social and, physical spheres of life as well as deteriorates equivalent reactions and the way body posture is maintained. In hearing impaired people, control of body balance and muscle coordination is often disturbed, thus more attention should be paid to exercises associated with balance which may improve the ability to learn and develop motor skills. Modified Pilates program was significantly more effective in improving body balance control than standard physical education classes in hearing impaired people.

Calcium Balance in Chronic Kidney Disease.

Science.gov (United States)

Hill Gallant, Kathleen M; Spiegel, David M

2017-06-01

The kidneys play a critical role in the balance between the internal milieu and external environment. Kidney failure is known to disrupt a number of homeostatic mechanisms that control serum calcium and normal bone metabolism. However, our understanding of calcium balance throughout the stages of chronic kidney disease is limited and the concept of balance itself, especially with a cation as complex as calcium, is often misunderstood. Both negative and positive calcium balance have important implications in patients with chronic kidney disease, where negative balance may increase risk of osteoporosis and fracture and positive balance may increase risk of vascular calcification and cardiovascular events. Here, we examine the state of current knowledge about calcium balance in adults throughout the stages of chronic kidney disease and discuss recommendations for clinical strategies to maintain balance as well as future research needs in this area. Recent calcium balance studies in adult patients with chronic kidney disease show that neutral calcium balance is achieved with calcium intake near the recommended daily allowance. Increases in calcium through diet or supplements cause high positive calcium balance, which may put patients at risk for vascular calcification. However, heterogeneity in calcium balance exists among these patients. Given the available calcium balance data in this population, it appears clinically prudent to aim for recommended calcium intakes around 1000 mg/day to achieve neutral calcium balance and avoid adverse effects of either negative or positive calcium balance. Assessment of patients' dietary calcium intake could further equip clinicians to make individualized recommendations for meeting recommended intakes.

Respiration and nitrogen assimilation: targeting mitochondria-associated metabolism as a means to enhance nitrogen use efficiency.

Science.gov (United States)

Foyer, Christine H; Noctor, Graham; Hodges, Michael

2011-02-01

Considerable advances in our understanding of the control of mitochondrial metabolism and its interactions with nitrogen metabolism and associated carbon/nitrogen interactions have occurred in recent years, particularly highlighting important roles in cellular redox homeostasis. The tricarboxylic acid (TCA) cycle is a central metabolic hub for the interacting pathways of respiration, nitrogen assimilation, and photorespiration, with components that show considerable flexibility in relation to adaptations to the different functions of mitochondria in photosynthetic and non-photosynthetic cells. By comparison, the operation of the oxidative pentose phosphate pathway appears to represent a significant limitation to nitrogen assimilation in non-photosynthetic tissues. Valuable new insights have been gained concerning the roles of the different enzymes involved in the production of 2-oxoglutarate (2-OG) for ammonia assimilation, yielding an improved understanding of the crucial role of cellular energy balance as a broker of co-ordinate regulation. Taken together with new information on the mechanisms that co-ordinate the expression of genes involved in organellar functions, including energy metabolism, and the potential for exploiting the existing flexibility for NAD(P)H utilization in the respiratory electron transport chain to drive nitrogen assimilation, the evidence that mitochondrial metabolism and machinery are potential novel targets for the enhancement of nitrogen use efficiency (NUE) is explored.

Farm nitrogen balances in six European landscapes as an indicator for nitrogen losses and basis for improved management

Directory of Open Access Journals (Sweden)

T. Dalgaard

2012-12-01

Full Text Available Improved management of nitrogen (N in agriculture is necessary to achieve a sustainable balance between the production of food and other biomass, and the unwanted effects of N on water pollution, greenhouse gas emissions, biodiversity deterioration and human health. To analyse farm N-losses and the complex interactions within farming systems, efficient methods for identifying emissions hotspots and evaluating mitigation measures are therefore needed. The present paper aims to fill this gap at the farm and landscape scales. Six agricultural landscapes in Poland (PL, the Netherlands (NL, France (FR, Italy (IT, Scotland (UK and Denmark (DK were studied, and a common method was developed for undertaking farm inventories and the derivation of farm N balances, N surpluses and for evaluating uncertainty for the 222 farms and 11 440 ha of farmland included in the study.

In all landscapes, a large variation in the farm N surplus was found, and thereby a large potential for reductions. The highest average N surpluses were found in the most livestock-intensive landscapes of IT, FR, and NL; on average 202 ± 28, 179 ± 63 and 178 ± 20 kg N ha⁻¹ yr⁻¹, respectively. All landscapes showed hotspots, especially from livestock farms, including a special UK case with large-scale landless poultry farming. Overall, the average N surplus from the land-based UK farms dominated by extensive sheep and cattle grazing was only 31 ± 10 kg N ha⁻¹ yr⁻¹, but was similar to the N surplus of PL and DK (122 ± 20 and 146 ± 55 kg N ha⁻¹ yr⁻¹, respectively when landless poultry farming was included.

We found farm N balances to be a useful indicator for N losses and the potential for improving N management. Significant correlations to N surplus were found, both with ammonia air concentrations and nitrate concentrations in soils and groundwater, measured during the period of N

Nitrogen in Chinese coals

Science.gov (United States)

Wu, D.; Lei, J.; Zheng, B.; Tang, X.; Wang, M.; Hu, Jiawen; Li, S.; Wang, B.; Finkelman, R.B.

2011-01-01

Three hundred and six coal samples were taken from main coal mines of twenty-six provinces, autonomous regions, and municipalities in China, according to the resource distribution and coal-forming periods as well as the coal ranks and coal yields. Nitrogen was determined by using the Kjeldahl method at U. S. Geological Survey (USGS), which exhibit a normal frequency distribution. The nitrogen contents of over 90% Chinese coal vary from 0.52% to 1.41% and the average nitrogen content is recommended to be 0.98%. Nitrogen in coal exists primarily in organic form. There is a slight positive relationship between nitrogen content and coal ranking. ?? 2011 Science Press, Institute of Geochemistry, CAS and Springer Berlin Heidelberg.

New Schemes for Positive Real Truncation

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Kari Unneland

2007-07-01

Full Text Available Model reduction, based on balanced truncation, of stable and of positive real systems are considered. An overview over some of the already existing techniques are given: Lyapunov balancing and stochastic balancing, which includes Riccati balancing. A novel scheme for positive real balanced truncation is then proposed, which is a combination of the already existing Lyapunov balancing and Riccati balancing. Using Riccati balancing, the solution of two Riccati equations are needed to obtain positive real reduced order systems. For the suggested method, only one Lyapunov equation and one Riccati equation are solved in order to obtain positive real reduced order systems, which is less computationally demanding. Further it is shown, that in order to get positive real reduced order systems, only one Riccati equation needs to be solved. Finally, this is used to obtain positive real frequency weighted balanced truncation.

Modelling the ecosystem effects of nitrogen deposition: Model of Ecosystem Retention and Loss of Inorganic Nitrogen (MERLIN

Directory of Open Access Journals (Sweden)

B. J. Cosby

1997-01-01

Full Text Available A catchment-scale mass-balance model of linked carbon and nitrogen cycling in ecosystems has been developed for simulating leaching losses of inorganic nitrogen. The model (MERLIN considers linked biotic and abiotic processes affecting the cycling and storage of nitrogen. The model is aggregated in space and time and contains compartments intended to be observable and/or interpretable at the plot or catchment scale. The structure of the model includes the inorganic soil, a plant compartment and two soil organic compartments. Fluxes in and out of the ecosystem and between compartments are regulated by atmospheric deposition, hydrological discharge, plant uptake, litter production, wood production, microbial immobilization, mineralization, nitrification, and denitrification. Nitrogen fluxes are controlled by carbon productivity, the C:N ratios of organic compartments and inorganic nitrogen in soil solution. Inputs required are: 1 temporal sequences of carbon fluxes and pools- 2 time series of hydrological discharge through the soils, 3 historical and current external sources of inorganic nitrogen; 4 current amounts of nitrogen in the plant and soil organic compartments; 5 constants specifying the nitrogen uptake and immobilization characteristics of the plant and soil organic compartments; and 6 soil characteristics such as depth, porosity, bulk density, and anion/cation exchange constants. Outputs include: 1 concentrations and fluxes of NO3 and NH4 in soil solution and runoff; 2 total nitrogen contents of the organic and inorganic compartments; 3 C:N ratios of the aggregated plant and soil organic compartments; and 4 rates of nitrogen uptake and immobilization and nitrogen mineralization. The behaviour of the model is assessed for a combination of land-use change and nitrogen deposition scenarios in a series of speculative simulations. The results of the simulations are in broad agreement with observed and hypothesized behaviour of nitrogen

Getting the Dimensions Right - Human Nutrition as Key for the Control of Regional Nitrogen Fluxes

Science.gov (United States)

Zessner, M.; Thaler, S.; Ruzicka, K.; Natho, S.

2009-04-01

The western society is rested upon a strong animal-based (meat, eggs, milk) nutrition, which is far of a healthy balanced diet. Furthermore, the production of animal based food consumes five to six times more resources (e.g.: area, fertilizer) compared to plant-based food and is closely connected to environmental pollution (e.g.: emission of greenhouse gases, water pollution). Especially the regional nitrogen turnover is highly driven by the request from human nutrition on agricultural production. While the efficiency of the transfer of applied nitrogen into the product is 60 - 70 % for vegetarian food, it is 15 - 25 % for animal based food. This contribution is going to demonstrate the most important nitrogen fluxes on national scale in Austria calculated using a national material flow analysis. The national nitrogen balance is driven by the production of nitrogen fertiliser and import of fooder. The airborne transport of reactive nitrogen (NOX and NHX) plays a decisive role within this balance. The main losses into the environment occur during the agricultural production process. Losses to the atmosphere exceed losses to groundwater and surface waters. After introduction of nitrogen removal at treatment plants, emissions to surface waters are dominated by land use driven fluxes via groundwater. The influence of nitrogen depositions on land (agricultural area, forest and mountain regions) on nitrogen emissions to the water system is in the same order of magnitude as the direct emissions due to fertiliser application - especially in a country as Austria with high shares of mountainous and silvicultural areas. Sources for depositions of reactive nitrogen are mainly NH3 emissions to the air from animal husbandry and NOX emissions to the air from traffic. Both substance are matter of transboundary transport and thus are highly influenced by activities outside a specific country or river catchment. Management of nitrogen on a national or catchment scale has therefore

δ15N constraints on long-term nitrogen balances in temperate forests

Science.gov (United States)

Perakis, S.S.; Sinkhorn, E.R.; Compton, J.E.

2011-01-01

Biogeochemical theory emphasizes nitrogen (N) limitation and the many factors that can restrict N accumulation in temperate forests, yet lacks a working model of conditions that can promote naturally high N accumulation. We used a dynamic simulation model of ecosystem N and δ15N to evaluate which combination of N input and loss pathways could produce a range of high ecosystem N contents characteristic of forests in the Oregon Coast Range. Total ecosystem N at nine study sites ranged from 8,788 to 22,667 kg ha−1 and carbon (C) ranged from 188 to 460 Mg ha−1, with highest values near the coast. Ecosystem δ15N displayed a curvilinear relationship with ecosystem N content, and largely reflected mineral soil, which accounted for 96–98% of total ecosystem N. Model simulations of ecosystem N balances parameterized with field rates of N leaching required long-term average N inputs that exceed atmospheric deposition and asymbiotic and epiphytic N2-fixation, and that were consistent with cycles of post-fire N2-fixation by early-successional red alder. Soil water δ15NO3 − patterns suggested a shift in relative N losses from denitrification to nitrate leaching as N accumulated, and simulations identified nitrate leaching as the primary N loss pathway that constrains maximum N accumulation. Whereas current theory emphasizes constraints on biological N2-fixation and disturbance-mediated N losses as factors that limit N accumulation in temperate forests, our results suggest that wildfire can foster substantial long-term N accumulation in ecosystems that are colonized by symbiotic N2-fixing vegetation.

Energy balance and greenhouse gas emissions of dryland camelina as influenced by tillage and nitrogen

International Nuclear Information System (INIS)

Keshavarz-Afshar, Reza; Mohammed, Yesuf Assen; Chen, Chengci

2015-01-01

Despite the great potential of camelina (Camelina sativa L. Crantz) as a promising biofuel feedstock, in-farm energy flow of the crop and its associated environmental impacts has not received sufficient attention from researchers. In order to assess net energy gain and to identify energy saving and environmental friendly production operations, a two year study was conducted at central Montana. We investigated the effects of tillage method (CT (conventional tillage) vs. NT (no-tillage)) and N (nitrogen) fertilizer rate (0, 45, 90 kg N ha −1 ) on energy balance and GHG (greenhouse gas emission) of dryland camelina production. Results indicated that energy input and GHG emission were 5 and 8% lower in NT than in CT. Application of 45 and 90 kg N ha −1 increased camelina energy input by 186 and 365%, while increased energy output by only 21 and 64%, respectively. There was no significant difference in net energy gain in response to N fertilization, but lower energy efficiency in response to higher N inputs. Averaged across tillage systems, the GHG emission was 32.0 kg C eq ha −1 with 0 N applied, and the GHG emission increased by 206 and 389% when 45 and 90 kg N ha −1 was applied. Overall, N fertilizer had the biggest share in total energy input. Averaged over all experimental treatments, 14,945 MJ ha −1 net energy was obtained from camelina crop in this study which shows the potential of this crop as a bioenergy feedstock. Our result showed that implementation of NT is strongly recommendable for camelina production in this region. Moreover, improvement of N use efficiency has the highest priority to improve energy performance and reduce GHG emissions in camelina production. - Highlights: • Camelina produced 14,945 MJ ha −1 of net energy in this study. • No tillage operation reduced 5% energy input and 8% greenhouse gas emission. • Nitrogen fertilizer was the most energy-intensive input in camelina production.

Determination of the Optimal Position of Pendulums of an Active Self-balancing Device

Science.gov (United States)

Ziyakaev, G. R.; Kazakova, O. A.; Yankov, V. V.; Ivkina, O. P.

2017-04-01

The demand of the modern manufacturing industry for machines with high motion speed leads to increased load and vibration activity of the main elements of rotor systems. Vibration reduces operating life of bearings, has adversary effects on human organism, and can cause accidents. One way to compensate for a rotating rotor's imbalance is the use of active self-balancing devices. The aim of this work is to determine the position of their pendulums, in which the imbalance is minimized. As a result of the study, a formula for determining the angle of the pendulums was obtained.

Nitrogen transformations in wetlands: Effects of water flow patterns

Energy Technology Data Exchange (ETDEWEB)

Davidsson, T.

1997-11-01

In this thesis, I have studied nitrogen turnover processes in water meadows. A water meadow is a wetland where water infiltrates through the soil of a grassland field. It is hypothesized that infiltration of water through the soil matrix promotes nutrient transformations compared to surface flow of water, by increasing the contact between water, nutrients, soil organic matter and bacteria. I have studied how the balance between nitrogen removal (denitrification, assimilative uptake, adsorption) and release (mineralization, desorption) processes are affected by water flow characteristics. Mass balance studies and direct denitrification measurements at two field sites showed that, although denitrification was high, net nitrogen removal in the water meadows was poor. This was due to release of ammonium and dissolved organic nitrogen (DON) from the soils. In laboratory studies, using {sup 15}N isotope techniques, I have shown that nitrogen turnover is considerably affected by hydrological conditions and by soil type. Infiltration increased virtually all the nitrogen processes, due to deeper penetration of nitrate and oxygen, and extended zones of turnover processes. On the contrary, soils and sediments with surface water flow, diffusion is the main transfer mechanism. The relation between release and removal processes sometimes resulted in shifts towards net nitrogen production. This occurred in infiltration treatments when ammonium efflux was high in relation to denitrification. It was concluded that ammonium and DON was of soil origin and hence not a product of dissimilatory nitrate reduction to ammonium. Both denitrification potential and mineralization rates were higher in peaty than in sandy soil. Vertical or horizontal subsurface flow is substantial in many wetland types, such as riparian zones, tidal salt marshes, fens, root-zone systems and water meadows. Moreover, any environment where aquatic and terrestrial ecosystems meet, and where water level fluctuates

One year variability of peak heights, heterozygous balance and inter-locus balance for the DNA positive control of AmpFℓSTR© Identifiler© STR kit.

Science.gov (United States)

Debernardi, A; Suzanne, E; Formant, A; Pène, L; Dufour, A B; Lobry, J R

2011-01-01

Multivariate analyses of 205 positive control experiments in an AmpFℓSTR© Identifiler© STR kit were used to analyze the factors affecting peak heights at 16 loci. Peak heights were found to be highly correlated between loci and there was evidence for a difference in sensitivity of the two genetic analyzers in the blue channel. Heterozygous balance response at 10 loci was found to behave as a random variable following a beta-distribution with typical median values of 90%, without locus or genetic analyzer effect. Inter-locus balance at 16 loci was influenced by the blue channel effect and a temporal switch of unexplained origin. The implications of these results for the choice of minimum threshold values in quality control are discussed. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

CHANGES IN NITROGEN FERTILIZERS MARKET IN POLAND IN 2000-2010

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Arkadiusz Zalewski

2013-12-01

Full Text Available The article describes the evolution of production, consumption and foreign trade of nitrogen fertilizers in Poland in years 2000-2010. The structure of the use of nitrogen fertilizers, foreign trade and balance of the market of urea, ammonium sulfate, ammonium nitrate, calcium ammonium nitrate, ammonium phosphate and UAN were analysed. Geographical directions of foreign trade were specified. The results showed that the domestic fertilizer sector is fully self-sufficient in the area of production of various nitrogen fertilizers. The most commonly used nitrogen fertilizers were: ammonium nitrate, urea and calcium ammonium nitrate while the importance of ammonium nitrate was clearly reduced. Ammonium sulphate and UAN produced mainly for export, and ammonium nitrate for the domestic market.

Ammonia-nitrogen and phosphates sorption from simulated reclaimed waters by modified clinoptilolite

International Nuclear Information System (INIS)

Huo, Hanxin; Lin, Hai; Dong, Yingbo; Cheng, Huang; Wang, Han; Cao, Lixia

2012-01-01

Highlights: ► The salt and thermally modified clinoptilolite can effectively sorb NH 3 -N and phosphates. ► The phosphorus and nitrogen removal was consistent with Langmuir isotherm model. ► The modified clinoptilolite possesses rapid adsorption and slow balance characteristics. ► The adsorption is more in line with the Elovich adsorption dynamics equation. ► The entropy effect plays the role of the main driving force in the adsorption. - Abstract: This paper presents the investigation of the ammonia-nitrogen and phosphates sorption from simulated reclaimed wastewater by modified clinoptilolite. The results showed that the modified clinoptilolite has a high sorption efficiency and removal performance. The ammonia-nitrogen and phosphates removal rate of the modified clinoptilolite reached to 98.46% and 99.80%, respectively. The surface of modified clinoptilolite became loose and some pores appeared, which enlarged the specific surface area; the contents of Na and Fe increased, and the contents of Ca and Mg decreased. The modified clinoptilolite possesses rapid sorption and slow balance characteristics and ammonia-nitrogen and phosphates sorption is more consistent with the Langmuir isotherm model. The adsorption kinetics of ammonia-nitrogen and phosphates follows the Elovich adsorption dynamics equation, which describes the sorption of ammonia-nitrogen and phosphates in aqueous solution as mainly a chemical sorption. Results from the thermodynamics experiment involving ammonia-nitrogen and phosphates sorption reveal that the process is a spontaneous and endothermic process, and is mainly driven by entropy effect.

Carbon-nitrogen feedbacks in the UVic ESCM

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R. Wania

2012-09-01

Full Text Available A representation of the terrestrial nitrogen cycle is introduced into the UVic Earth System Climate Model (UVic ESCM. The UVic ESCM now contains five terrestrial carbon pools and seven terrestrial nitrogen pools: soil, litter, leaves, stem and roots for both elements and ammonium and nitrate in the soil for nitrogen. Nitrogen cycles through plant tissue, litter, soil and the mineral pools before being taken up again by the plant. Biological N₂ fixation and nitrogen deposition represent external inputs to the plant-soil system while losses occur via leaching. Simulated carbon and nitrogen pools and fluxes are in the range of other models and observations. Gross primary production (GPP for the 1990s in the CN-coupled version is 129.6 Pg C a⁻¹ and net C uptake is 0.83 Pg C a⁻¹, whereas the C-only version results in a GPP of 133.1 Pg C a⁻¹ and a net C uptake of 1.57 Pg C a⁻¹. At the end of a transient experiment for the years 1800–1999, where radiative forcing is held constant but CO₂ fertilisation for vegetation is permitted to occur, the CN-coupled version shows an enhanced net C uptake of 1.05 Pg C a⁻¹, whereas in the experiment where CO₂ is held constant and temperature is transient the land turns into a C source of 0.60 Pg C a⁻¹ by the 1990s. The arithmetic sum of the temperature and CO₂ effects is 0.45 Pg C a⁻¹, 0.38 Pg C a⁻¹ lower than seen in the fully forced model, suggesting a strong nonlinearity in the CN-coupled version. Anthropogenic N deposition has a positive effect on Net Ecosystem Production of 0.35 Pg C a⁻¹. Overall, the UVic CN-coupled version shows similar characteristics to other CN-coupled Earth System Models, as measured by net C balance and sensitivity to changes in climate, CO₂ and temperature.

[Nitrogen Fraction Distributions and Impacts on Soil Nitrogen Mineralization in Different Vegetation Restorations of Karst Rocky Desertification].

Science.gov (United States)

Hu, Ning; Ma, Zhi-min; Lan, Jia-cheng; Wu, Yu-chun; Chen, Gao-qi; Fu, Wa-li; Wen, Zhi-lin; Wang, Wen-jing

2015-09-01

In order to illuminate the impact on soil nitrogen accumulation and supply in karst rocky desertification area, the distribution characteristics of soil nitrogen pool for each class of soil aggregates and the relationship between aggregates nitrogen pool and soil nitrogen mineralization were analyzed in this study. The results showed that the content of total nitrogen, light fraction nitrogen, available nitrogen and mineral nitrogen in soil aggregates had an increasing tendency along with the descending of aggregate-size, and the highest content was occurred in 5mm and 2-5 mm classes, and the others were the smallest. With the positive vegetation succession, the weight percentage of > 5 mm aggregate-size classes was improved and the nitrogen storage of macro-aggregates also was increased. Accordingly, the capacity of soil supply mineral nitrogen and storage organic nitrogen were intensified.

Effect of application approaches of ammonium bicarbonate on yield of spring wheat and nitrogen balance

International Nuclear Information System (INIS)

Wen Xianfang; Pan Jiarong; Zheng Xingyun

1995-01-01

The results from 15 N-tracing experiment showed that at the same rate of nitrogen application, the nitrogen utilization ammonium bicarbonate was 33.50%, 32.30% and 23.19% respectively and the nitrogen loss rate of ammonium bicarbonate was 22.12%, 26.93% and 45.32% respectively for fertilizer mixed thoroughly with soil before sowing, buried into soil and spread on the surface of soil at both joining stage (1/2N) and booting stage (1/2N) of spring wheat. The nitrogen utilization of ammonium bicarbonate for top-application at both joining (1/2N) and booting stage (1/2N) was significantly lower but nitrogen loss rate was significantly higher than that of either thorough incorporation with soil or deep application at joining and booting stages. Between the latter treatments there was no significantly difference observed. There was no significant difference in biomass and grain yield of spring wheat between the former treatment and either of the latter treatments, indicating that buried into soil or mixed with soil thoroughly as a basal fertilizer was an available approach to increase the nitrogen availability of ammonium bicarbonate and crop yield. It was also shown that no significant difference in biomass and grain yield of spring wheat between deep application of ammonium bicarbonate and top-application of urea at the same rate of N application

High nitrogen availability reduces polyphenol content in Sphagnum peat.

Science.gov (United States)

Bragazza, Luca; Freeman, Chris

2007-05-15

Peat mosses of the genus Sphagnum constitute the bulk of living and dead biomass in bogs. These plants contain peculiar polyphenols which hamper litter peat decomposition through their inhibitory activity on microbial breakdown. In the light of the increasing availability of biologically active nitrogen in natural ecosystems, litter derived from Sphagnum mosses is an ideal substrate to test the potential effects of increased atmospheric nitrogen deposition on polyphenol content in litter peat. To this aim, we measured total nitrogen and soluble polyphenol concentration in Sphagnum litter peat collected in 11 European bogs under a chronic gradient of atmospheric nitrogen deposition. Our results demonstrate that increasing nitrogen concentration in Sphagnum litter, as a consequence of increased exogenous nitrogen availability, is accompanied by a decreasing concentration of polyphenols. This inverse relationship is consistent with reports that in Sphagnum mosses, polyphenol and protein biosynthesis compete for the same precursor. Our observation of modified Sphagnum litter chemistry under chronic nitrogen eutrophication has implications in the context of the global carbon balance, because a lower content of decay-inhibiting polyphenols would accelerate litter peat decomposition.

Nitrogen utilization in pigs fed diets with soybean and rapeseed products leading to different ileal endogenous nitrogen losses

NARCIS (Netherlands)

Grala, W.; Verstegen, M.W.A.; Jansman, A.J.M.; Huisman, J.; Wasilewko, J.

1998-01-01

Nitrogen (N) balance was determined in 36 pigs (BW 24 to 30 kg) fed diets inducing different ileal endogenous N losses (ENL). We tested the hypothesis that enhanced ENL may be indicative of a higher recycling of endogenous proteins that will induce a greater urinary N loss and a lower efficiency of

Positive streamers in air and nitrogen of varying density: experiments on similarity laws

International Nuclear Information System (INIS)

Briels, T M P; Van Veldhuizen, E M; Ebert, U

2008-01-01

Positive streamers in ambient air at pressures from 0.013 to 1 bar are investigated experimentally. The voltage applied to the anode needle ranges from 5 to 45 kV, the discharge gap from 1 to 16 cm. Using a 'slow' voltage rise time of 100-180 ns, the streamers are intentionally kept thin. For each pressure p, we find a minimal diameter d min . To test whether streamers at different pressures are similar, the minimal streamer diameter d min is multiplied by its pressure p; we find this product to be well approximated by p · d min = 0.20 ± 0.02 mm bar over two decades of air pressure at room temperature. The value also fits diameters of sprite discharges above thunderclouds at an altitude of 80 km when extrapolated to room temperature (as air density rather than pressure determines the physical behaviour). The minimal velocity of streamers in our measurements is approximately 0.1 mm ns -1 = 10 5 m s -1 . The same minimal velocity has been reported for tendrils in sprites. We also investigate the size of the initial ionization cloud at the electrode tip from which the streamers emerge, and the streamer length between branching events. The same quantities are also measured in nitrogen with a purity of approximately 99.9%. We characterize the essential differences with streamers in air and find a minimal diameter of p · d min = 0.12 ± 0.02 mm bar in our nitrogen.

Carbon-nitrogen interactions and biomass partitioning of Carex rostrata grown at three levels of nitrogen supply

Energy Technology Data Exchange (ETDEWEB)

Saarinen, T [Helsinki Univ. (Finland). Dept. of Ecology and Systematics

1997-12-31

Biomass and production of vascular plants constitutes a major source of carbon input in peatlands. As rates of decomposition vary considerably with depth, the vertical distribution of biomass may substantially affect accumulation of carbon in peatlands. Therefore, allocation patterns between shoot and roots are particularly important when considering carbon balance of peatland ecosystems. The stimulatory effect of increasing atmospheric concentration of CO{sub 2} or photosynthesis may increase availability of carbon to most C3 plants. Availability of nitrogen may also alter both due to increased atmospheric deposition and changer in mineralisation rates associated with climate change. Most root-shoot partitioning models predict that allocation of biomass is dependent of the availability and uptake of carbon and nitrogen. A decrease in supply of carbon would favour allocation to shoots and a decrease in supply of nitrogen would increase allocation to roots. At a cellular level, non structural carbohydrates and free amino acids are thought to represent the biochemically available fraction of carbon and nitrogen, respectively. The aim of this work is study the long-term growth responses of Carex rostrata to changes in the availability of nitrogen. Special attention is paid to soluble sugars ant free amino acids, which may control partitioning of biomass. (10 refs.)

Carbon-nitrogen interactions and biomass partitioning of Carex rostrata grown at three levels of nitrogen supply

Energy Technology Data Exchange (ETDEWEB)

Saarinen, T. [Helsinki Univ. (Finland). Dept. of Ecology and Systematics

1996-12-31

Biomass and production of vascular plants constitutes a major source of carbon input in peatlands. As rates of decomposition vary considerably with depth, the vertical distribution of biomass may substantially affect accumulation of carbon in peatlands. Therefore, allocation patterns between shoot and roots are particularly important when considering carbon balance of peatland ecosystems. The stimulatory effect of increasing atmospheric concentration of CO{sub 2} or photosynthesis may increase availability of carbon to most C3 plants. Availability of nitrogen may also alter both due to increased atmospheric deposition and changer in mineralisation rates associated with climate change. Most root-shoot partitioning models predict that allocation of biomass is dependent of the availability and uptake of carbon and nitrogen. A decrease in supply of carbon would favour allocation to shoots and a decrease in supply of nitrogen would increase allocation to roots. At a cellular level, non structural carbohydrates and free amino acids are thought to represent the biochemically available fraction of carbon and nitrogen, respectively. The aim of this work is study the long-term growth responses of Carex rostrata to changes in the availability of nitrogen. Special attention is paid to soluble sugars ant free amino acids, which may control partitioning of biomass. (10 refs.)

Modeling Nitrogen Decrease in Water Lettuce Ponds from Waste Stabilization Ponds

Science.gov (United States)

Putri, Gitta Agnes; Sunarsih

2018-02-01

This paper presents about the dynamic modeling of the Water Lettuce ponds as a form of improvement from the Water Hyacinth ponds. The purpose of this paper is to predict nitrogen decrease and nitrogen transformation in Water Lettuce ponds integrated with Waste Stabilization Ponds. The model consists of 4 mass balances, namely Dissolved Organic Nitrogen (DON), Particulate Organic Nitrogen (PON), ammonium (NH4+), Nitrate and Nitrite (NOx). The process of nitrogen transformation which considered in a Water Lettuce ponds, namely hydrolysis, mineralization, nitrification, denitrification, plant and bacterial uptake processes. Numerical simulations are performed by giving the values of parameters and the initial values of nitrogen compounds based on a review of previous studies. Numerical results show that the rate of change in the concentration of nitrogen compounds in the integration ponds of waste stabilization and water lettuce decreases and reaches stable at different times.

The Position of Mineral Nitrogen Fertilizer in Efficient Use of Nitrogen and Land: A Review

NARCIS (Netherlands)

Schroder, J.J.

2014-01-01

Our attitude towards mineral nitrogen (N) fertilizers is ambivalent. N fertilizers have on one hand increased our supply of food, feed and other bio-based raw materials tremendously and also improved the use efficiency of land and labor, but have on the other hand a negative impact on the quality of

Positive feedback of greenhouse gas balances to warming is determined by non-growing season emissions in an alpine meadow

Science.gov (United States)

Niu, S.; Wang, J.; Quan, Q.; Chen, W.; Wen, X.; Yu, G.

2017-12-01

Large uncertainties exist in the sources and sinks of greenhouse gases (CO2, CH4, N2O) in response to climate warming and human activity. So far, numerous previous studies have evaluated the CO2 budget, but little attention has paid to CH4 and N2O budgets and the concurrent balance of these three gases in combination, especially in the non-growing season. Here, we synthesized eddy covariance measurement with the automatic chamber measurements of CO2, CH4, and N2O exposed to three levels of temperature treatments (ambient, +1.5 °C, +2.5 °C) and two disturbance treatments (ummowing, mowing) in an alpine meadow on the Tibetan Plateau. We have found that warming caused increase in CH4 uptake and decrease in N2O emission offset little of the enhancement in CO2 emission, triggering a positive feedback to climate warming. Warming switches the ecosystem from a net sink (-17 ± 14 g CO2-eq m-2 yr-1) in the control to a net source of greenhouse gases of 94 ± 36 gCO2-eq m-2 yr-1 in the plots with +1.5 °C warming treatment, and 177 ± 6 gCO2-eq m-2 yr-1 in the plots with +2.5 °C warming treatment. The changes in the non-growing season balance, rather than those in the growing season, dominate the warming responses of annual greehouse gas balance. And this is not changed by mowing. The dominant role of responses of winter greenhouse gas balance in the positive feedback of ecosystem to climate warming highlights that greenhouse gas balance in cold season has to be considered when assessing climate-carbon cycle feedback.

Orbital storage and supply of subcritical liquid nitrogen

Science.gov (United States)

Aydelott, John C.

1990-01-01

Subcritical cryogenic fluid management has long been recognized as an enabling technology for key propulsion applications, such as space transfer vehicles (STV) and the on-orbit cryogenic fuel depots which will provide STV servicing capability. The LeRC Cryogenic Fluids Technology Office (CFTO), under the sponsorship of OAST, has the responsibility of developing the required technology via a balanced program involving analytical modeling, ground based testing, and in-space experimentation. Topics covered in viewgraph form include: cryogenic management technologies; nitrogen storage and supply; cryogenic nitrogen cooling capability; and LN2 system demonstration technical objectives.

Enhanced nitrogen deposition over China

Energy Technology Data Exchange (ETDEWEB)

Liu, Xuejun; Zhang, Ying; Han, Wenxuan; Tang, Aohan; Shen, Jianlin; Cui, Zhenling; Christie, Peter; Zhang, Fusuo [College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 (China); Vitousek, Peter [Department of Biology, Stanford University, Stanford, California 94305 (United States); Erisman, Jan Willem [VU University Amsterdam, 1081 HV Amsterdam (Netherlands); Goulding, Keith [The Sustainable Soils and Grassland Systems Department, Rothamsted Research, Harpenden AL5 2JQ (United Kingdom); Fangmeier, Andreas [Institute of Landscape and Plant Ecology, University of Hohenheim, 70593 Stuttgart (Germany)

2013-02-28

China is experiencing intense air pollution caused in large part by anthropogenic emissions of reactive nitrogen. These emissions result in the deposition of atmospheric nitrogen (N) in terrestrial and aquatic ecosystems, with implications for human and ecosystem health, greenhouse gas balances and biological diversity. However, information on the magnitude and environmental impact of N deposition in China is limited. Here we use nationwide data sets on bulk N deposition, plant foliar N and crop N uptake (from long-term unfertilized soils) to evaluate N deposition dynamics and their effect on ecosystems across China between 1980 and 2010. We find that the average annual bulk deposition of N increased by approximately 8 kilograms of nitrogen per hectare (P < 0.001) between the 1980s (13.2 kilograms of nitrogen per hectare) and the 2000s (21.1 kilograms of nitrogen per hectare). Nitrogen deposition rates in the industrialized and agriculturally intensified regions of China are as high as the peak levels of deposition in northwestern Europe in the 1980s, before the introduction of mitigation measures. Nitrogen from ammonium (NH4+) is the dominant form of N in bulk deposition, but the rate of increase is largest for deposition of N from nitrate (NO3-), in agreement with decreased ratios of NH3 to NOx emissions since 1980. We also find that the impact of N deposition on Chinese ecosystems includes significantly increased plant foliar N concentrations in natural and semi-natural (that is, non-agricultural) ecosystems and increased crop N uptake from long-term-unfertilized croplands. China and other economies are facing a continuing challenge to reduce emissions of reactive nitrogen, N deposition and their negative effects on human health and the environment.

Genotypic variation of nitrogen use efficiency in Indian mustard

International Nuclear Information System (INIS)

Ahmad, Altaf; Khan, Ishrat; Abrol, Yash P.; Iqbal, Muhammad

2008-01-01

This experiment was conducted to investigate the variation of nitrogen efficiency (NE), nitrogen uptake efficiency (UE), physiological nitrogen use efficiency (PUE) among Indian mustard genotypes, grown under N-insufficient and N-sufficient conditions. Nitrogen efficiency varied from 52.7 to 92.8. Seed yield varied from 1.14 t ha -1 to 3.21 t ha -1 under N-insufficient condition, while 2.14 t ha -1 -3.33 t ha -1 under N-sufficient condition. Physiological basis of this difference was explained in terms of nitrogen uptake efficiency and physiological nitrogen use efficiency, and their relationship with the growth and yield characteristics. While nitrogen uptake efficiency was positively correlated with plant biomass (0.793**), leaf area index (0.664*), and leaf nitrogen content (0.783**), physiological nitrogen use efficiency is positively correlated with photosynthetic rate (0.689**) and yield (0.814**). This study suggests that genotype having high nitrogen uptake efficiency and high physiological nitrogen use efficiency might help in reducing the nitrogen load on soil without any penalty on the yield. - Nitrogen efficient crop plants may help in reducing environmental contamination of nitrate without any penalty on seed yield

Streamer knotwilg branching: sudden transition in morphology of positive streamers in high-purity nitrogen

International Nuclear Information System (INIS)

Heijmans, L C J; Clevis, T T J; Nijdam, S; Van Veldhuizen, E M; Ebert, U

2015-01-01

We describe a peculiar branching phenomenon in positive repetitive streamer discharges in high purity nitrogen. We name it knotwilg branching after the Dutch word for a pollard willow tree. In a knotwilg branching a thick streamer suddenly splits into many thin streamers. Under some conditions this happens for all streamers in a discharge at about the same distance from the high-voltage electrode tip. At this distance, the thick streamers suddenly bend sharply and appear to propagate over a virtual surface surrounding the high-voltage electrode, rather than following the background electric field lines. From these bent thick streamers many, much thinner, streamers emerge that roughly follow the background electric field lines, creating the characteristic knotwilg branching. We have only found this particular morphology in high purity nitrogen at pressures in the range 50 to 200 mbar and for pulse repetition rates above 1 Hz; the experiments were performed for an electrode distance of 16 cm and for fast voltage pulses of 20 or 30 kV. These observations clearly disagree with common knowledge on streamer propagation. We have analyzed the data of several tens of thousands of discharges to clarify the phenomena. We also present some thoughts on how the ionization of the previous discharges could concentrate into some pre-ionization region near the needle electrode and create the knotwilg morphology, but we present no final explanation. (paper)

Nitrogen cycling in a flooded-soil ecosystem planted to rice (Oryza sativa L.)

International Nuclear Information System (INIS)

Reddy, K.R.

1982-01-01

15 N studies of various aspects of the nitrogen cycle in a flooded rice ecosystem on Crowley silt loam soil in Louisiana were reviewed to construct a mass balance model of the nitrogen cycle for this system. Nitrogen transformations modeled included 1) net ammonification (0.22 mg NH 4+ -N kg dry soil - 1 day - 1 ). 2) net nitrification (207 mg NO 3- -N kg dry soil - 1 day - 1 ). 3) denitrification (0.37 mg N kg dry soil - 1 day - 1 ), and 4) biological N 2 fixation (0.16 mg N kg dry soil - 1 day - 1 ). Nitrogen inputs included 1) application of fertilizers, 2) incorporation of crop residues, 3) biological N 2 fixation, and 4) deposition. Nitrogen outputs included 1) crop removal, 2) gaseous losses from NH 3 volatilization and simultaneous occurrence of nitrification-denitrification, and 3) leaching and runoff. Mass balance calculations indicated that 33% of the available inorganic nitrogen was recovered by rice, and the remaining nitrogen was lost from the system. Losses of N due to ammonia volatilization were minimal because fertilizer-N was incorporated into the soil. A significant portion of inorganic-N was lost by ammonium diffusion from the anaerobic layer to the aerobic layer in response to a concentration gradient and subsequent nitrification in the aerobic layer followed by nitrate diffusion into the anaerobic layer and denitrification into gaseous end products. Leaching and surface runoff losses were minimal. (orig.)

Nitrogen waste from rainbow trout (Oncorhynchus mykiss) with particular focus on urea

DEFF Research Database (Denmark)

Dalsgaard, Anne Johanne Tang; Larsen, Bodil Katrine; Pedersen, Per Bovbjerg

2015-01-01

a laboratory, mass-balance approach, the current study examined the effects of commercially applied feeding levels on the loading of different N waste forms, including daily fluctuations in dissolved total nitrogen (TN), total ammonia nitrogen (TAN), urea-N, and non-characterized, dissolved N deriving from...... juvenile rainbow trout (Oncorhynchus mykiss). In addition, the study examined whether there was a removal of urea-N across a moving bed biofilter operated as end-of-pipe under commercial conditions. The laboratory, mass-balance study showed that there were no effects of feeding levels (1.3, 1.5 or 1....../nitrogen. Results from the commercially operated, nitrifying biofilter showed that urea-N was removed at a rate of 0.014 g N m2 day−1. Compared to the removal of TAN (0.208 g N m2 day−1), the moving bed biofilter was 1.07 times more active in removing dissolved N than immediately expected when only considering TAN...

Mass and element balance in food waste composting facilities.

Science.gov (United States)

Zhang, Huijun; Matsuto, Toshihiko

2010-01-01

The mass and element balance in municipal solid waste composting facilities that handle food waste was studied. Material samples from the facilities were analyzed for moisture, ash, carbon, nitrogen, and the oxygen consumption of compost and bulking material was determined. Three different processes were used in the food waste composting facilities: standard in-vessel composting, drying, and stand-alone composting machine. Satisfactory results were obtained for the input/output ash balance despite several assumptions made concerning the quantities involved. The carbon/nitrogen ratio and oxygen consumption values for compost derived only from food waste were estimated by excluding the contribution of the bulking material remaining in the compost product. These estimates seemed to be suitable indices for the biological stability of compost because there was a good correlation between them, and because the values seemed logical given the operating conditions at the facilities. 2010 Elsevier Ltd. All rights reserved.

Nitrogen Metabolism in Lactating Goats Fed with Diets Containing Different Protein Sources

Directory of Open Access Journals (Sweden)

A. B. Santos

2014-05-01

Full Text Available This study aimed to evaluate urea excretion, nitrogen balance and microbial protein synthesis in lactating goats fed with diets containing different protein sources in the concentrate (soybean meal, cottonseed meal, aerial part of cassava hay and leucaena hay. Four Alpine goats whose mean body weight was 42.6±6.1 kg at the beginning of the experiment, a mean lactation period of 94.0±9.0 days and a production of 1.7±0.4 kg of milk were distributed in a 4×4 Latin square with four periods of 15 days. Diets were formulated to be isonitrogenous, containing 103.0 g/kg of CP, 400 g/kg of Tifton 85 hay and 600 g/kg of concentrate. Diet containing cottonseed meal provided (p<0.05 increased excretion of urea and urea nitrogen in the urine (g/d and mg/kg of BW when compared with leucaena hay. The diets affected the concentrations of urea nitrogen in plasma (p<0.05 and excretion of urea nitrogen in milk, being that soybean meal and cottonseed meal showed (p<0.05 higher than the average aerial part of the cassava hay. The use of diets with cottonseed meal as protein source in the concentrate in feeding of lactating goats provides greater nitrogen excretion in urine and negative nitrogen balance, while the concentrate with leucaena hay as a source of protein, provides greater ruminal microbial protein synthesis.

The OSU1/QUA2/TSD2-encoded putative methyltransferase is a critical modulator of carbon and nitrogen nutrient balance response in Arabidopsis.

Directory of Open Access Journals (Sweden)

Peng Gao

2008-01-01

Full Text Available The balance between carbon (C and nitrogen (N nutrients must be tightly coordinated so that cells can optimize their opportunity for metabolism, growth and development. However, the C and N nutrient balance perception and signaling mechanism remains poorly understood. Here, we report the isolation and characterization of two allelic oversensitive to sugar 1 mutants (osu1-1, osu1-2 in Arabidopsis thaliana. Using the cotyledon anthocyanin accumulation and root growth inhibition assays, we show that the osu1 mutants are more sensitive than wild-type to both of the imbalanced C/N conditions, high C/low N and low C/high N. However, under the balanced C/N conditions (low C/low N or high C/high N, the osu1 mutants have similar anthocyanin levels and root lengths as wild-type. Consistently, the genes encoding two MYB transcription factors (MYB75 and MYB90 and an Asn synthetase isoform (ASN1 are strongly up-regulated by the OSU1 mutation in response to high C/low N and low C/high N, respectively. Furthermore, the enhanced sensitivity of osu1-1 to high C/low N with respect to anthocyanin accumulation but not root growth inhibition can be suppressed by co-suppression of MYB75, indicating that MYB75 acts downstream of OSU1 in the high C/low N imbalance response. Map-based cloning reveals that OSU1 encodes a member of a large family of putative methyltransferases and is allelic to the recently reported QUA2/TSD2 locus identified in genetic screens for cell-adhesion-defective mutants. Accumulation of OSU1/QUA2/TSD2 transcript was not regulated by C and N balance, but the OSU1 promoter was slightly more active in the vascular system. Taken together, our results show that the OSU1/QUA2/TSD2-encoded putative methyltransferase is required for normal C/N nutrient balance response in plants.

Positive responses of belowground C dynamics to nitrogen enrichment in China.

Science.gov (United States)

Deng, Lei; Peng, Changhui; Zhu, Guangyu; Chen, Lei; Liu, Yulin; Shangguan, Zhouping

2018-03-01

Determining how nitrogen (N) impacts ecosystem carbon (C) cycling is critical to using C sequestration to offset anthropogenic CO 2 emissions. The N deposition rate in China is higher than the global average; however, many results of N enrichment experiments in China have not been included in global syntheses. In this study, we assembled a large dataset that comprised 124 published studies concerning N addition experiments, including 570 observations at 127 sites across China, to quantify the responses of belowground C dynamics to N enrichment in terrestrial ecosystems in China by a meta-analysis. The results showed that overall soil organic C, dissolved organic C (DOC) and soil microbial biomass C (MBC) increased by 1.8, 7.4, and 8.8%, respectively (Penrichment; belowground biomass and litter increased by 14.6 and 24.4%, respectively (Penrichment promoted C inputs into the soil mainly by increasing litter and belowground biomass inputs. Additionally, N enrichment increased C output by increasing soil respiration. Land use type and N addition level had different impacts on the soil C pool and on soil respiration. DOC, MBC, and litter exhibited more positive responses to N deposition in cooler and more arid regions than in other regions. The meta-analysis indicated that N enrichment had a positive impact on belowground C cycles in China. Climate played a greater role than did N deposition level in affecting processes of ecosystem C cycling. Moreover, belowground C cycle processes are determined by complicated interactions among land use type, N enrichment, and climate. Copyright © 2017 Elsevier B.V. All rights reserved.

Positive streamers in air and nitrogen of varying density: experiments on similarity laws

Energy Technology Data Exchange (ETDEWEB)

Briels, T M P; Van Veldhuizen, E M; Ebert, U [Department of Applied Physics, Technische Universiteit Eindhoven, P O Box 513, 5600 MB Eindhoven (Netherlands)], E-mail: ebert@cwi.nl, E-mail: e.m.v.veldhuizen@tue.nl

2008-12-07

Positive streamers in ambient air at pressures from 0.013 to 1 bar are investigated experimentally. The voltage applied to the anode needle ranges from 5 to 45 kV, the discharge gap from 1 to 16 cm. Using a 'slow' voltage rise time of 100-180 ns, the streamers are intentionally kept thin. For each pressure p, we find a minimal diameter d{sub min}. To test whether streamers at different pressures are similar, the minimal streamer diameter d{sub min} is multiplied by its pressure p; we find this product to be well approximated by p {center_dot} d{sub min} = 0.20 {+-} 0.02 mm bar over two decades of air pressure at room temperature. The value also fits diameters of sprite discharges above thunderclouds at an altitude of 80 km when extrapolated to room temperature (as air density rather than pressure determines the physical behaviour). The minimal velocity of streamers in our measurements is approximately 0.1 mm ns{sup -1} = 10{sup 5} m s{sup -1}. The same minimal velocity has been reported for tendrils in sprites. We also investigate the size of the initial ionization cloud at the electrode tip from which the streamers emerge, and the streamer length between branching events. The same quantities are also measured in nitrogen with a purity of approximately 99.9%. We characterize the essential differences with streamers in air and find a minimal diameter of p {center_dot} d{sub min} = 0.12 {+-} 0.02 mm bar in our nitrogen.

A Bayesian approach to infer nitrogen loading rates from crop and land-use types surrounding private wells in the Central Valley, California

Science.gov (United States)

Ransom, Katherine M.; Bell, Andrew M.; Barber, Quinn E.; Kourakos, George; Harter, Thomas

2018-05-01

This study is focused on nitrogen loading from a wide variety of crop and land-use types in the Central Valley, California, USA, an intensively farmed region with high agricultural crop diversity. Nitrogen loading rates for several crop types have been measured based on field-scale experiments, and recent research has calculated nitrogen loading rates for crops throughout the Central Valley based on a mass balance approach. However, research is lacking to infer nitrogen loading rates for the broad diversity of crop and land-use types directly from groundwater nitrate measurements. Relating groundwater nitrate measurements to specific crops must account for the uncertainty about and multiplicity in contributing crops (and other land uses) to individual well measurements, and for the variability of nitrogen loading within farms and from farm to farm for the same crop type. In this study, we developed a Bayesian regression model that allowed us to estimate land-use-specific groundwater nitrogen loading rate probability distributions for 15 crop and land-use groups based on a database of recent nitrate measurements from 2149 private wells in the Central Valley. The water and natural, rice, and alfalfa and pasture groups had the lowest median estimated nitrogen loading rates, each with a median estimate below 5 kg N ha-1 yr-1. Confined animal feeding operations (dairies) and citrus and subtropical crops had the greatest median estimated nitrogen loading rates at approximately 269 and 65 kg N ha-1 yr-1, respectively. In general, our probability-based estimates compare favorably with previous direct measurements and with mass-balance-based estimates of nitrogen loading. Nitrogen mass-balance-based estimates are larger than our groundwater nitrate derived estimates for manured and nonmanured forage, nuts, cotton, tree fruit, and rice crops. These discrepancies are thought to be due to groundwater age mixing, dilution from infiltrating river water, or denitrification

Nitrogen fertilization plans for the main crops of Turkey to mitigate nitrates pollution

Directory of Open Access Journals (Sweden)

Theodore Karyotis

2014-01-01

Full Text Available To create a rational nitrogen fertilization plan, a mass nitrogen (N balance was used for the main crops of Turkey. The following components are included in the suggested N fertilization plans: the quantity of N fertilizer which is required by the crop for a targeted and sustainable yield, nitrogen inputs available to the crop without fertilization, nitrogen losses mainly due to nitrates leaching and emissions to the atmosphere. This simple equation was transformed to a more detailed one and fertilization plans are based on the total N required to produce a crop of a targeted yield, N mineralized from Soil Organic Matter (SOM, the residual plant available inorganic N before sowing or planting, input of nitrogen from rainfall and losses through leaching and emissions. This work is based on available data and is an open sheet balance which can be easily used by local authorities. Decreased N fertilization can be applied without significant yield reduction and this can be explained by increased N use efficiency, as a result of proper time of application and splitting of N fertilizers in doses. This model can be appropriately adapted according to site-specific conditions, whilst new parameters can be added to improve precision of the performed calculations.

A tradeoff frontier for global nitrogen use and cereal production

International Nuclear Information System (INIS)

Mueller, Nathaniel D; West, Paul C; Gerber, James S; MacDonald, Graham K; Foley, Jonathan A; Polasky, Stephen

2014-01-01

Nitrogen fertilizer use across the world’s croplands enables high-yielding agricultural production, but does so at considerable environmental cost. Imbalances between nitrogen applied and nitrogen used by crops contributes to excess nitrogen in the environment, with negative consequences for water quality, air quality, and climate change. Here we utilize crop input-yield models to investigate how to minimize nitrogen application while achieving crop production targets. We construct a tradeoff frontier that estimates the minimum nitrogen fertilizer needed to produce a range of maize, wheat, and rice production levels. Additionally, we explore potential environmental consequences by calculating excess nitrogen along the frontier using a soil surface nitrogen balance model. We find considerable opportunity to achieve greater production and decrease both nitrogen application and post-harvest excess nitrogen. Our results suggest that current (circa 2000) levels of cereal production could be achieved with ∼50% less nitrogen application and ∼60% less excess nitrogen. If current global nitrogen application were held constant but spatially redistributed, production could increase ∼30%. If current excess nitrogen were held constant, production could increase ∼40%. Efficient spatial patterns of nitrogen use on the frontier involve substantial reductions in many high-use areas and moderate increases in many low-use areas. Such changes may be difficult to achieve in practice due to infrastructure, economic, or political constraints. Increases in agronomic efficiency would expand the frontier to allow greater production and environmental gains

Effects of dietary crude protein and rumen-degradable protein concentrations on urea recycling, nitrogen balance, omasal nutrient flow, and milk production in dairy cows.

Science.gov (United States)

Mutsvangwa, T; Davies, K L; McKinnon, J J; Christensen, D A

2016-08-01

The objective of this study was to determine how interactions between dietary crude protein (CP) and rumen-degradable protein (RDP) concentrations alter urea-nitrogen recycling, nitrogen (N) balance, omasal nutrient flow, and milk production in lactating Holstein cows. Eight multiparous Holstein cows (711±21kg of body weight; 91±17d in milk at the start of the experiment) were used in a replicated 4×4 Latin square design with a 2×2 factorial arrangement of dietary treatments and 29-d experimental periods. Four cows in one Latin square were fitted with ruminal cannulas to allow ruminal and omasal sampling. The dietary treatment factors were CP (14.9 vs. 17.5%; dry matter basis) and RDP (63 vs. 69% of CP) contents. Dietary RDP concentration was manipulated by including unprocessed or micronized canola meal. Diet adaptation (d 1-20) was followed by 8d (d 21-29) of sample and data collection. Continuous intrajugular infusions of [(15)N(15)N]-urea (220mg/d) were conducted for 4d (d 25-29) with concurrent total collections of urine and feces to estimate N balance and whole-body urea kinetics. Proportions of [(15)N(15)N]- and [(14)N(15)N]-urea in urinary urea, and (15)N enrichment in feces were used to calculate urea kinetics. For the low-CP diets, cows fed the high-RDP diet had a greater DM intake compared with those fed the low-RDP diet, but the opposite trend was observed for cows fed the high-CP diets. Dietary treatment had no effect on milk yield. Milk composition and milk component yields were largely unaffected by dietary treatment; however, on the low-CP diets, milk fat yield was greater for cows fed the low-RDP diet compared with those fed the high-RDP diet, but it was unaffected by RDP concentration on the high-CP diets. On the high-CP diets, milk urea nitrogen concentration was greater in cows fed the high-RDP diet compared with those fed the low-RDP diet, but it was unaffected by RDP concentration on the low-CP diets. Ruminal NH3-N concentration tended to

Challenges in quantifying biosphere-atmosphere exchange of nitrogen species

DEFF Research Database (Denmark)

Sutton, M.A.; Nemitz, E.; Erisman, J.W.

2007-01-01

Recent research in nitrogen exchange with the atmosphere has separated research communities according to N form. The integrated perspective needed to quantify the net effect of N on greenhouse-gas balance is being addressed by the NitroEurope Integrated Project (NEU). Recent advances have depende...

Variation and balance of positive air ion concentrations in a boreal forest

Directory of Open Access Journals (Sweden)

U. Hõrrak

2008-02-01

Full Text Available Air ions are characterized on the basis of measurements carried out in a boreal forest at the Hyytiälä SMEAR station, Finland, during the BIOFOR III campaign in spring 1999. The air ions were discriminated as small ions (charged molecular aggregates of the diameter of less than 2.5 nm, intermediate ions (charged aerosol particles of the diameter of 2.5–8 nm, and large ions (charged aerosol particles of the diameter of 8–20 nm. Statistical characteristics of the ion concentrations and the parameters of ion balance in the atmosphere are presented separately for the nucleation event days and non-event days. In the steady state, the ionization rate is balanced with the loss of small ions, which is expressed as the product of the small ion concentration and the ion sink rate. The widely known sinks of small ions are the recombination with small ions of opposite polarity and attachment to aerosol particles. The dependence of small ion concentration on the concentration of aerosol particles was investigated applying a model of the bipolar diffusion charging of particles by small ions. When the periods of relative humidity above 95% and wind speed less than 0.6 m s⁻¹ were excluded, then the small ion concentration and the theoretically calculated small ion sink rate were closely negatively correlated (correlation coefficient −87%. However, an extra ion loss term of the same magnitude as the ion loss onto aerosol particles is needed for a quantitative explanation of the observations. This term is presumably due to the small ion deposition on coniferous forest. The hygroscopic growth correction of the measured aerosol particle size distributions was also found to be necessary for the proper estimation of the ion sink rate. In the case of nucleation burst events, the concentration of small positive ions followed the general balance equation, no extra ion loss in addition to the deposition on coniferous forest was detected, and the

Exogenous trehalose improves growth under limiting nitrogen through upregulation of nitrogen metabolism.

Science.gov (United States)

Lin, Yingchao; Zhang, Jie; Gao, Weichang; Chen, Yi; Li, Hongxun; Lawlor, David W; Paul, Matthew J; Pan, Wenjie

2017-12-19

The trehalose (Tre) pathway has strong effects on growth and development in plants through regulation of carbon metabolism. Altering either Tre or trehalose 6-phosphate (T6P) can improve growth and productivity of plants as observed under different water availability. As yet, there are no reports of the effects of modification of Tre orT6P on plant performance under limiting nutrition. Here we report that nitrogen (N) metabolism is positively affected by exogenous application of Tre in nitrogen-deficient growing conditions. Spraying foliage of tobacco (Nicotiana tabacum) with trehalose partially alleviated symptoms of nitrogen deficiency through upregulation of nitrate and ammonia assimilation and increasing activities of nitrate reductase (NR), glycolate oxidase (GO), glutamine synthetase (GS) and glutamine oxoglutarate aminotransferase (GOGAT) with concomitant changes in ammonium (NH 4 + ) and nitrate (NO 3 - ) concentrations, glutamine and amino acids. Chlorophyll and total nitrogen content of leaves and rates of photosynthesis were increased compared to nitrogen-deficient plants without applied Tre. Total plant biomass accumulation was also higher in Tre -fed nitrogen-deficient plants, with a smaller proportion of dry weight partitioned to roots, compared to nitrogen-deficient plants without applied Tre. Consistent with higher nitrogen assimilation and growth, Tre application reduced foliar starch. Minimal effects of Tre feeding were observed on nitrogen-sufficient plants. The data show, for the first time, significant stimulatory effects of exogenous Tre on nitrogen metabolism and growth in plants growing under deficient nitrogen. Under such adverse conditions metabolism is regulated for survival rather than productivity. Application of Tre can alter this regulation towards maintenance of productive functions under low nitrogen. This has implications for considering approaches to modifying the Tre pathway for to improve crop nitrogen-use efficiency and

Nitrogen dynamics in a soil-sugar cane system

International Nuclear Information System (INIS)

Oliveira, Julio Cesar Martins de; Reichardt, Klaus; Bacchi, Osny O.S.; Timm, Luis Carlos; Tominaga, Tania Toyomi; Castro Navarro, Roberta de; Cassaro, Fabio Augusto Meira; Dourado-Neto, Durval; Trivelin, Paulo Cesar Ocheuse; Piccolo, Marisa de Cassia

2000-01-01

Results of an organic matter management experiment of a sugar cane crop are reported for the first cropping year. Sugar cane was planted in October 1997, and labeled with a 15 N fertilizer pulse to study the fate of organic matter in the soil-plant system. A nitrogen balance is presented, partitioning the system in plant components (stalk, tip and straw), soil components (five soil organic matter fractions) and evaluating leaching losses. The 15 N label permitted to determine, at the end of the growing season, amounts of nitrogen derived from the fertilizer, present in the above mentioned compartments. (author)

Nitrogen Requirements and Balance of Protected Cucumber in Coastal Lebanon

International Nuclear Information System (INIS)

Atallah, T.

2003-01-01

Protected cultures are widespread along the Lebanese narrow coastline, encouraged by mild winter conditions. Although one of the most intensive production systems, water and nutrients managements are mostly empirical, based on the experience of the grower himself or of his workers. So far, water has been available in Lebanon, but it will become scarce within ten years. The conservation of water quality by a rational addition of nutrients is particularly relevant to protected cultures. This is important as greenhouses are developed on imported shallow soils that could be fragile and highly vulnerable to pollution. Sound management includes the amount and the forms of fertilizers as well as the modality of fertigation. An experiment was conducted during two spring seasons in a location along the northern coast in a typical unheated greenhouse. The cucumber response to two frequencies and modalities of fertigation was followed: continuous T2C and T3C and discontinuous T2D and T3D every two and three days respectively. Nitrogen recovery by the crop was possible through the use of 15 N-labeled fertilizers. An evaluation of the nitrogen fertilizer fate in the plant-soil system was undertaken in 1999, despite large proportions of Ndff(%) plant N fertilizer recovery was smaller than in the previous season and did not exceed 55% of N inputs

Enhanced photosynthetic capacity increases nitrogen metabolism through the coordinated regulation of carbon and nitrogen assimilation in Arabidopsis thaliana.

Science.gov (United States)

Otori, Kumi; Tanabe, Noriaki; Maruyama, Toshiki; Sato, Shigeru; Yanagisawa, Shuichi; Tamoi, Masahiro; Shigeoka, Shigeru

2017-09-01

Plant growth and productivity depend on interactions between the metabolism of carbon and nitrogen. The sensing ability of internal carbon and nitrogen metabolites (the C/N balance) enables plants to regulate metabolism and development. In order to investigate the effects of an enhanced photosynthetic capacity on the metabolism of carbon and nitrogen in photosynthetically active tissus (source leaves), we herein generated transgenic Arabidopsis thaliana plants (ApFS) that expressed cyanobacterial fructose-1,6-/sedoheptulose-1,7-bisphosphatase in their chloroplasts. The phenotype of ApFS plants was indistinguishable from that of wild-type plants at the immature stage. However, as plants matured, the growth of ApFS plants was superior to that of wild-type plants. Starch levels were higher in ApFS plants than in wild-type plants at 2 and 5 weeks. Sucrose levels were also higher in ApFS plants than in wild-type plants, but only at 5 weeks. On the other hand, the contents of various free amino acids were lower in ApFS plants than in wild-type plants at 2 weeks, but were similar at 5 weeks. The total C/N ratio was the same in ApFS plants and wild-type plants, whereas nitrite levels increased in parallel with elevations in nitrate reductase activity at 5 weeks in ApFS plants. These results suggest that increases in the contents of photosynthetic intermediates at the early growth stage caused a temporary imbalance in the free-C/free-N ratio and, thus, the feedback inhibition of the expression of genes involved in the Calvin cycle and induction of the expression of those involved in nitrogen metabolism due to supply deficient free amino acids for maintenance of the C/N balance in source leaves of ApFS plants.

Mass-Balance Constraints on Nutrient Cycling in Tropical Seagrass Beds

NARCIS (Netherlands)

Erftemeijer, P.L.A.; Middelburg, J.J.

1995-01-01

A relatively simple mass balance model is presented to study the cycling of nutrients (nitrogen and phosphorus) in tropical seagrass beds. The model is based on quantitative data on nutrient availability, seagrass primary production, community oxygen metabolism, seagrass tissue nutrient contents,

RESEARCH INTO THE USE OF DIETARY NITROGEN BY GROWING AND FATTENING STEERS IN RELATION TO DIET FORMULATION AND ENERGY CONTENT

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I. VOICU

2008-05-01

Full Text Available Investigations were done on the use of the dietary nitrogen by fattening steers between 300-450 kg using the method of in vivo nutrient digestibility and nitrogen balance. Alfalfa and corn-based diets were used, in different forms of preservation and with different ratio of the bulk forage to the concentrate feeds; diet digestibility expressed as organic matter and protein varied between 72-76% and between 66- 75% respectively; the best performance produced by the corn silage diets were observed in diet 2 (with ammonia, while the best results produced by the alfalfa diets was noticed in diet 5 (haylage; nitrogen balance showed the highest values of the retained nitrogen in the alfalfa half-hay diet, the alfalfa hay diet having lower values.

Relationship of Nitrogen Use Efficiency with the Activities of Enzymes Involved in Nitrogen Uptake and Assimilation of Finger Millet Genotypes Grown under Different Nitrogen Inputs

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Nidhi Gupta

2012-01-01

Full Text Available Nitrogen responsiveness of three-finger millet genotypes (differing in their seed coat colour PRM-1 (brown, PRM-701 (golden, and PRM-801 (white grown under different nitrogen doses was determined by analyzing the growth, yield parameters and activities of nitrate reductase (NR, glutamine synthetase (GS, glutamate synthase; GOGAT, and glutamate dehydrogenase (GDH at different developmental stages. High nitrogen use efficiency and nitrogen utilization efficiency were observed in PRM-1 genotype, whereas high nitrogen uptake efficiency was observed in PRM-801 genotype. At grain filling nitrogen uptake efficiency in PRM-1 negatively correlated with NR, GS, GOGAT activities whereas it was positively correlated in PRM-701 and PRM-801, however, GDH showed a negative correlation. Growth and yield parameters indicated that PRM-1 responds well at high nitrogen conditions while PRM-701 and PRM-801 respond well at normal and low nitrogen conditions respectively. The study indicates that PRM-1 is high nitrogen responsive and has high nitrogen use efficiency, whereas golden PRM-701 and white PRM-801 are low nitrogen responsive genotypes and have low nitrogen use efficiency. However, the crude grain protein content was higher in PRM-801 genotype followed by PRM-701 and PRM-1, indicating negative correlation of nitrogen use efficiency with source to sink relationship in terms of seed protein content.

Variation in foliar nitrogen and albedo in response to nitrogen fertilization and elevated CO2

Science.gov (United States)

Haley F. Wicklein; Scott V. Ollinger; Mary E. Martin; David Y. Hollinger; Lucie C. Lepine; Michelle C. Day; Megan K. Bartlett; Andrew D. Richardson; Richard J. Norby

2012-01-01

Foliar nitrogen has been shown to be positively correlated with midsummer canopy albedo and canopy near infrared (NIR) reflectance over a broad range of plant functional types (e.g., forests, grasslands, and agricultural lands). To date, the mechanism(s) driving the nitrogen-albedo relationship have not been established, and it is unknown whether factors affecting...

Surface N Balances in Agricultural Crop production systems in China for the period 1980-2015

NARCIS (Netherlands)

Sun, B.; Shen, R.P.; Bouwman, A.F.

2008-01-01

Surface nitrogen (N) balances for China's crop production systems were estimated using statistical data collected from 1980 to 2004 at the national and provincial scale and from 1994 to 1999 at the county level. There was a surplus N balance throughout these periods, but the surplus was nearly

Optimising Nitrogen utilization by fertigated protected cucumber in coastal Lebanon

International Nuclear Information System (INIS)

Atallah, Therese; Darwich, Talal; Awad, Souhail; El-Moujabber, Maroun

1999-01-01

Full text.In Lebanon, protected cultures are in expansion with indications of new greenhouses installed every year, particularly at altitudes between 400 and 500 m. In these intensive systems, few studies looked at the crop requirements, the management practices and their consequences on the soil and water. This study was carried out under field conditions in Jbeil (lebanon) at 100 m of altitude for a spring cucumber. For the follow-up of the nitrogen use efficiency, labelled nitrogen fertilizer (with the heavy isotope 15 N) was used. Treatments consisted of combining two irrigation frequencies: every 2 or 3 days with two modalities of fertigation: continuous and discontinuous, with every other irrigation. Otherwise, the levels of water and nutrients were equal among all treatments. Results focused on the plant performance under these modalities and also on the nitrogen balance in the plant-soil system. The plants fertigated continuously, every two days, presented higher fresh fruit yield and above-ground dry ,matter production. In addition, the number of non-commercial fruits were significantly smaller than in the other treatments. This suggests less stressful conditions under the continuous input of nutrients and the stable EC of the fertigation solution. Concerning the nitrogen balance, it was calculated by the difference between input removal for each treatment. These values were compared with the nitrate-nitrogen build-up in the soil. Very close correspondence was found, which indicates minimal nitrogen losses for all treatments which could be related to the amount accumulated in the soil as nitrates. Overall, under the experimental conditions the continuous fertigation at a 2-day frequency was the most adequate in promoting plant production and minimizing losses from the soil-plant system

[Balance trainability using the Nintendo Wii balance board in sportive people].

Science.gov (United States)

Paukowits, S; Stöggl, T

2014-03-01

A multivariable training has a positive impact on balance skills and risk of injury. To date the effect of this training using the Nintendo Wii balance board in sportive people has not yet been investigated. The aim of this study was to investigate whether training with the Nintendo Wii balance board can improve balance skills. 20 people were randomized into a control and an intervention group each with 10 people who performed a unilateral stance test with eyes open and closed as well as the star excursion balance test before and after the intervention. The control group completed their usual sports and the intervention group an adjunct training with the Nintendo Wii balance board for 4 weeks. Adjunct Training using the Nintendo Wii Balance Board did not improve sportive people's balance skills significantly. The intervention group, however, attained better results in the star excursion balance test, whereas the control group did not show any changes. The unilateral stance tests did not provide significant differences before and after training within both groups. The use of the Nintendo Wii balance board should be further investigated by employing individual difficulty levels. © Georg Thieme Verlag KG Stuttgart · New York.

Transport and Retention of Nitrogen, Phosphorus and Carbon in North America’s Largest River Swamp Basin, the Atchafalaya River Basin

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Y. Jun Xu

2013-04-01

Full Text Available Floodplains and river corridor wetlands may be effectively managed for reducing nutrients and carbon. However, our understanding is limited to the reduction potential of these natural riverine systems. This study utilized the long-term (1978–2004 river discharge and water quality records from an upriver and a downriver location of the Atchafalaya River to quantify the inflow, outflow, and inflow–outflow mass balance of total Kjeldahl nitrogen (TKN = organic nitrogen + ammonia nitrogen, nitrate + nitrite nitrogen (NO3 + NO2, total phosphorous (TP, and total organic carbon (TOC through the largest river swamp basin in North America. The study found that, over the past 27 years, the Atchafalaya River Basin (ARB acted as a significant sink for TKN (annual retention: 24%, TP (41%, and TOC (12%, but a source for NO3 + NO2 nitrogen (6%. On an annual basis, ARB retained 48,500 t TKN, 16,900 t TP, and 167,100 t TOC from the river water. The retention rates were closely and positively related to the river discharge with highs during the winter and spring and lows in the late summer. The higher NO3 + NO2 mass outflow occurred throughout spring and summer, indicating an active role of biological processes on nitrogen as water and air temperatures in the basin rise.

Understanding Plant Nitrogen Metabolism through Metabolomics and Computational Approaches

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Perrin H. Beatty

2016-10-01

Full Text Available A comprehensive understanding of plant metabolism could provide a direct mechanism for improving nitrogen use efficiency (NUE in crops. One of the major barriers to achieving this outcome is our poor understanding of the complex metabolic networks, physiological factors, and signaling mechanisms that affect NUE in agricultural settings. However, an exciting collection of computational and experimental approaches has begun to elucidate whole-plant nitrogen usage and provides an avenue for connecting nitrogen-related phenotypes to genes. Herein, we describe how metabolomics, computational models of metabolism, and flux balance analysis have been harnessed to advance our understanding of plant nitrogen metabolism. We introduce a model describing the complex flow of nitrogen through crops in a real-world agricultural setting and describe how experimental metabolomics data, such as isotope labeling rates and analyses of nutrient uptake, can be used to refine these models. In summary, the metabolomics/computational approach offers an exciting mechanism for understanding NUE that may ultimately lead to more effective crop management and engineered plants with higher yields.

Ash recycling to spruce and beech stands effects on nutrients, growth, nitrogen dynamics and carbon balance; Askaaterfoering till gran- och bokbestaand - effekter paa naering, tillvaext, kvaevedynamik och kolbalans

Energy Technology Data Exchange (ETDEWEB)

Thelin, Gunnar

2006-03-15

spruce stands The ash treatments appear to have given the positive effects aimed at without negative effects on the carbon balance and the nitrogen dynamics. In addition, tree growth increased in the spruce stands. The positive effects were, however, small on the soil chemistry and the soil water chemistry. The dose two tons of wood-ash and two tons of lime appear to have been too low in order to improve the mineral soil pH and the acid neutralizing capacity (ANC) in the soil water. This is probably due to desorption of historically deposited sulfate. The dose appears to be too low to compensate for whole tree harvest losses of K and P. It is probable that the increased tree growth was caused by the increased tree P-status. This is reinforced by the positive correlation between the tree growth and the needle P concentration and the lack of correlation between the tree growth and the needle N concentration. The improved nutrient status of the trees and the soil implies an improved future sustainable production capacity and makes the trees more stress resistant. There is a high possibility of good profitability in ash recycling for the land owner.

Influence of second kind collisions on the electron distribution function in the positive column of low pressure nitrogen discharge

International Nuclear Information System (INIS)

Rohlena, K.; Ruzicka, T.

1979-01-01

A numerical solution of the Boltzmann equation for the electron gas in the positive column of a DC discharge in nitrogen is presented. The Boltzmann equation was solved with the inclusion of the second-kind (superelastic) collisions proceeding from the first six excited vibrational levels of molecular nitrogen. The vibrational level population is supposed to follow the Boltzmann distribution for the given vibrational temperature Tsub(v), with a possible deviation of the ground level, which can be overpopulated in the given ratio γ. Apart from the electron distribution functions, which were gained for various values of E/p 0 , Tsub(v) and γ, the values of some production frequencies and kinetic coefficients are presented in form of tables and plots. It is found that the electron distribution (and also the corresponding production rates) only above a certain energy limit depends on Tsub(v) and γ through the normalization constant. (author)

Options for including nitrogen management in climate policy

International Nuclear Information System (INIS)

Erisman, J.W.

2010-12-01

The outline of the presentation is as follows: Climate change and nitrogen; Nitrogen and climate interlinkages; Options for nitrogen management; Report, workshop and IPCC; and Conclusions. The concluding remarks are: Fertilizing the biosphere with reactive nitrogen compounds lead to ecosystem, health, water and climate impacts; Nitrogen deposition can lead to additional carbon sequestration and to impacts on biodiversity and ecosystem services; Nitrogen addition to the biosphere might have a net cooling effect of 1 W/m 2 ; Life Cycle Analysis is needed to show the full impact; and Nitrogen management is essential for the environment and can have a positive effect on the net GHG exchange.

Feeding behavior, microbial efficiency, and nitrogen balance of Nellore heifers supplemented with crude glycerin

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Gonçalo Mesquita da Silva

2016-09-01

Full Text Available This study aimed to evaluate the inclusion of crude glycerin in diets for Nellore heifers grazing on a Brachiaria brizantha pasture, during the dry season, on urine and plasma urea concentrations, feeding behavior, and microbial protein synthesis. Sixty Nellore heifers with an average initial weight of 285.89 ± 18.74 kg, at approximately 19 ± 2 months of age, were distributed, in a completely randomized design, into the following five treatments with twelve replicates: 0.00, 4.00, 8.00, 12.00, and 16.00% inclusion of crude glycerin in the diet they were fed. Grazing time decreased linearly (P 0.05, averaging 113.73g CP per kg TDN ingested. Plasma nitrogen concentration did not show any effects (P > 0.05, averaging 13.11 mg dL?1. Supplementing heifers during the dry season, at 0.7% BW, using up to 16% crude glycerin in the diet composition, did not elicit positive responses from feeding behavior and had little influence on microbial synthesis.

Maintenance of energy expenditure on high-protein vs. high-carbohydrate diets at a constant body weight may prevent a positive energy balance.

Science.gov (United States)

Martens, E A; Gonnissen, H K; Gatta-Cherifi, B; Janssens, P L; Westerterp-Plantenga, M S

2015-10-01

Relatively high-protein diets are effective for body weight loss, and subsequent weight maintenance, yet it remains to be shown whether these diets would prevent a positive energy balance. Therefore, high-protein diet studies at a constant body weight are necessary. The objective was to determine fullness, energy expenditure, and macronutrient balances on a high-protein low-carbohydrate (HPLC) diet compared with a high-carbohydrate low-protein (HCLP) diet at a constant body weight, and to assess whether effects are transient or sustained after 12 weeks. A randomized parallel study was performed in 14 men and 18 women [mean ± SD age: 24 ± 5 y; BMI (in kg/m(2)): 22.8 ± 2.0] on diets containing 30/35/35 (HPLC) or 5/60/35 (HCLP) % of energy from protein/carbohydrate/fat. Significant interactions between dietary intervention and time on total energy expenditure (TEE) (P = 0.013), sleeping metabolic rate (SMR) (P = 0.040), and diet-induced thermogenesis (DIT) (P = 0.027) appeared from baseline to wk 12. TEE was maintained in the HPLC diet group, while it significantly decreased throughout the intervention period in the HCLP diet group (wk 1: P = 0.002; wk 12: P = 0.001). Energy balance was maintained in the HPLC diet group, and became positive in the HCLP diet group at wk 12 (P = 0.008). Protein balance varied directly according to the amount of protein in the diet, and diverged significantly between the diets (P = 0.001). Fullness ratings were significantly higher in the HPLC vs. the HCLP diet group at wk 1 (P = 0.034), but not at wk 12. Maintenance of energy expenditure on HPLC vs. HCLP diets at a constant body weight may prevent development of a positive energy balance, despite transiently higher fullness. The study was registered on clinicaltrials.gov with Identifier: NCT01551238. Copyright © 2014 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Ammonia Nitrogen Added to Diets Deficient in Dispensable Amino Acid Nitrogen Is Poorly Utilized for Urea Production in Growing Pigs.

Science.gov (United States)

Mansilla, Wilfredo D; Silva, Kayla E; Zhu, Cuilan L; Nyachoti, Charles M; Htoo, John K; Cant, John P; de Lange, Cornelis Fm

2017-12-01

Background: Including ammonia in low-crude protein (CP) diets deficient in dispensable amino acid (DAAs) increases nitrogen retention in growing pigs. Objective: We investigated the absorption and metabolism of dietary ammonia nitrogen in the portal-drained viscera (PDV) and liver of pigs fed a diet deficient in DAA nitrogen. Methods: Eight pigs with an initial mean ± SD body weight (BW) of 26.5 ± 1.4 kg were surgically fitted with 4 catheters each (portal, hepatic and mesenteric veins, and carotid artery). The pigs were fed (2.8 × 191 kcal/kg BW 0.60 ), for 7 d and every 8 h, a diet deficient in DAA nitrogen supplemented with increasing amounts of ammonia nitrogen (CP: 7.76%, 9.27%, and 10.77%; indispensable amino acid nitrogen:total nitrogen ratio: 0.71, 0.59, and 0.50 for control and low- and high-ammonia diets, respectively). The treatment sequence was based on a Latin square design with 3 consecutive periods. On the last day of each period, blood flows in the portal and hepatic veins were determined with a continuous infusion of ρ-amino hippuric acid into the mesenteric vein. Serial blood samples were taken to determine ammonia and urea nitrogen concentration. Net balances of ammonia and urea nitrogen were calculated for the PDV and liver. Results: Cumulative (8 h) ammonia nitrogen appearance in the portal vein increased ( P ≤ 0.05) with ammonia intake (433, 958, and 1629 ± 60 mg ammonia nitrogen/meal for control and low- and high-ammonia diets, respectively). The cumulative hepatic uptake of ammonia nitrogen increased ( P ≤ 0.05) with ammonia nitrogen supply. The cumulative urea nitrogen appearance in the hepatic vein tended to increase ( P ≤ 0.10) only in high-ammonia treatment (-92.5, -59.4, and 209.7 ± 92 mg urea nitrogen/meal for control and low- and high-ammonia diets, respectively) and, relative to the control diet, represented -6.0% and 11% of ammonia nitrogen intake. Conclusion: Dietary ammonia nitrogen is poorly utilized for urea

Effects of plane of nutrition on growth, feed intake, digestibility and nitrogen balance in Murrah graded male buffalo (Bubalus bubalis) calves in Nepal.

Science.gov (United States)

Kumagai, Hajime; Baral, Bodh R; Shiino, Tatsu; Devkota, Naba R; Oishi, Kazato; Hirooka, Hiroyuki; Kolachhapati, Mana R; Tiwari, Ishwor C P

2012-01-01

An experiment was conducted using 17 male buffalo calves to assess the effects of plane of nutrition on dry matter intake (DMI), daily gain (DG), body size measurement, apparent digestibility and nitrogen (N) balance. To attain 250kg BW, the calves were allocated into three groups: H, L-H and L, receiving the concentrate at 1.50% of BW, 0.75% of BW until 190kg BW and 1.50% thereafter and 0.75% of BW, respectively. The animals had ad libitum access to urea-treated rice straw (UTRS). The DMI of UTRS through the experiment was higher in L and L-H than H, showing 3.52, 2.90 and 2.62kg/day, respectively (Pcalves in Nepal. © 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

Balance sheet method assessment for nitrogen fertilization in winter wheat: II. alternative strategies using the CropSyst simulation model

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Maria Corbellini

2006-09-01

Full Text Available It is important, both for farmer profit and for the environment, to correctly dose fertilizer nitrogen (N for winter wheat growth. Balance-sheet methods are often used to calculate the recommended dose of N fertilizer. Other methods are based on the dynamic simulation of cropping systems. Aim of the work was to evaluate the balance-sheet method set up by the Region Emilia-Romagna (DPI, by comparing it with the cropping systems simulation model CropSyst (CS, and with an approach based on fixed supplies of N (T. A 3-year trial was structured as a series of N fertility regimes at 3 sites (Papiano di Marsciano, Ravenna, San Pancrazio. The N-regimes were generated at each site-year as separate trials in which 3 N rates were applied: N1 (DPI, N2 (DPI+50 kg ha-1 N at spike initiation, N3 (DPI + 50 kg ha-1 N at early booting. Above ground biomass and soil data (NO3-N and water were sampled and used to calibrate CS. Doses of fertilizer N were calculated by both DPI and CS for winter wheat included in three typical rotations for Central and Northern Italy. Both these methods and method T were simulated at each site over 50 years, by using daily generated weather data. The long-term simulation allowed evaluating such alternative fertilization strategies. DPI and CS estimated comparable crop yields and N leached amounts, and both resulted better than T. Minor risk of leaching emerged for all N doses. The N2 and N3 rates allowed slightly higher crop yields than N1.

Comparison of five organic wastes regarding their behaviour during composting: Part 2, nitrogen dynamic

International Nuclear Information System (INIS)

Guardia, A. de; Mallard, P.; Teglia, C.; Marin, A.; Le Pape, C.; Launay, M.; Benoist, J.C.; Petiot, C.

2010-01-01

This paper aimed to compare household waste, separated pig solids, food waste, pig slaughterhouse sludge and green algae regarding processes ruling nitrogen dynamic during composting. For each waste, three composting simulations were performed in parallel in three similar reactors (300 L), each one under a constant aeration rate. The aeration flows applied were comprised between 100 and 1100 L/h. The initial waste and the compost were characterized through the measurements of their contents in dry matter, total carbon, Kjeldahl and total ammoniacal nitrogen, nitrite and nitrate. Kjeldahl and total ammoniacal nitrogen and nitrite and nitrate were measured in leachates and in condensates too. Ammonia and nitrous oxide emissions were monitored in continue. The cumulated emissions in ammonia and in nitrous oxide were given for each waste and at each aeration rate. The paper focused on process of ammonification and on transformations and transfer of total ammoniacal nitrogen. The parameters of nitrous oxide emissions were not investigated. The removal rate of total Kjeldahl nitrogen was shown being closely tied to the ammonification rate. Ammonification was modelled thanks to the calculation of the ratio of biodegradable carbon to organic nitrogen content of the biodegradable fraction. The wastes were shown to differ significantly regarding their ammonification ability. Nitrogen balances were calculated by subtracting nitrogen losses from nitrogen removed from material. Defaults in nitrogen balances were assumed to correspond to conversion of nitrate even nitrite into molecular nitrogen and then to the previous conversion by nitrification of total ammoniacal nitrogen. The pool of total ammoniacal nitrogen, i.e. total ammoniacal nitrogen initially contained in waste plus total ammoniacal nitrogen released by ammonification, was calculated for each experiment. Then, this pool was used as the referring amount in the calculation of the rates of accumulation, stripping and

Nitrogen-Doped Graphene:Effects of nitrogen species on the properties of the vanadium redox flow battery

International Nuclear Information System (INIS)

Shi, Lang; Liu, Suqin; He, Zhen; Shen, Junxi

2014-01-01

Nitrogen-doped graphene nanosheets (NGS), prepared by a simple hydrothermal reaction of graphene oxide (GO) with urea as nitrogen source were studied as positive electrodes in vanadium redox flow battery (VRFB). The synthesized NGS with the nitrogen level as high as 10.12 atom% is proven to be a promising material for VRFB. The structures and electrochemical properties of the materials are investigated by scanning electron microscopy, X-ray photoelectron spectroscopy, cyclic voltammetry and electrochemical impendence spectroscopy. The results demonstrate that not only the nitrogen doping level but the nitrogen type in the NGS are significant for its catalytic activity towards the [VO] 2+ /[VO 2 ] + redox couple reaction. In more detail, among four types of nitrogen species (pyridinic-N, pyrrolic-N, quaternary-N, oxidic-N) doped into the graphene lattice, quaternary-N play mainly roles for improving the catalytic activity toward the [VO] 2+ /[VO 2 ] + couple reaction

Nitrogen 15 abundance in protein fractions of beans fertilized with (15NH4)2SO4

International Nuclear Information System (INIS)

Chaud, Saula Goulart; Oliveira, Admar Costa de; Trivelin, Paulo Cesar Ocheuze

2002-01-01

Studies evaluating the protein nutritive value of beans labelled with 15 N, using nitrogen balance and the quantitation of faecal and urinary endogenous nitrogen, determined by isotopic dilution, have been extensively used. The objective of this research was to verify if the isotopic labelling of raw, freeze dried beans (Phaseolus vulgaris L., cultivar Pirata 1) with 1.394 atoms % 15 N, resulted in the same abundance of the whole flour and of the protein fractions extracted from the beans with 0.5 mol L -1 NaCl. The isotopic abundance found in the whole bean flour, in the protein extract, in the globulin and albumin fractions were respectively: 1.394 +- 0.011; 1.403 +- 0.012; 1.399 +- 0.007 and 1.399 +- 0.028 atoms % of 15 N, presenting no difference (P > 0.05). However, a difference was found (P < 0.05) between the above mentioned abundances and the isotopic abundance found in the nitrogen of the proteins in the extraction residue, which was 0.969 +- 0.084. Since the abundances did not differ, the protein nutritive indexes, such as digestibility and biological value, determined from the nitrogen balance and corrected for isotopic dilution, would not be affected by extracting the proteins from the beans with 0.5 mol L 1 NaCl. If working with the nitrogen balance of the residual proteins after extraction and even with the whole flours, these indexes could present incorrect values, since the isotopic labelling of the residual proteins was less than that of the protein fractions. (author)

Challenges of including nitrogen effects on decomposition in earth system models

Science.gov (United States)

Hobbie, S. E.

2011-12-01

Despite the importance of litter decomposition for ecosystem fertility and carbon balance, key uncertainties remain about how this fundamental process is affected by nitrogen (N) availability. Nevertheless, resolving such uncertainties is critical for mechanistic inclusion of such processes in earth system models, towards predicting the ecosystem consequences of increased anthropogenic reactive N. Towards that end, we have conducted a series of experiments examining nitrogen effects on litter decomposition. We found that both substrate N and externally supplied N (regardless of form) accelerated the initial decomposition rate. Faster initial decomposition rates were linked to the higher activity of carbohydrate-degrading enzymes associated with externally supplied N and the greater relative abundances of Gram negative and Gram positive bacteria associated with green leaves and externally supplied organic N (assessed using phospholipid fatty acid analysis, PLFA). By contrast, later in decomposition, externally supplied N slowed decomposition, increasing the fraction of slowly decomposing litter and reducing lignin-degrading enzyme activity and relative abundances of Gram negative and Gram positive bacteria. Our results suggest that elevated atmospheric N deposition may have contrasting effects on the dynamics of different soil carbon pools, decreasing mean residence times of active fractions comprising very fresh litter, while increasing those of more slowly decomposing fractions including more processed litter. Incorporating these contrasting effects of N on decomposition processes into models is complicated by lingering uncertainties about how these effects generalize across ecosystems and substrates.

Body protein losses estimated by nitrogen balance and potassium-40 counting

International Nuclear Information System (INIS)

Belyea, R.L.; Babbitt, C.L.; Sedgwick, H.T.; Zinn, G.M.

1986-01-01

Body protein losses estimated from N balance were compared with those estimated by 40K counting. Six nonlactating dairy cows were fed an adequate N diet for 7 wk, a low N diet for 9 wk, and a replete N diet for 3 wk. The low N diet contained high cell wall grass hay plus ground corn, starch, and molasses. Soybean meal was added to the low N diet to increase N in the adequate N and replete N diets. Intake was measured daily. Digestibilities, N balance, and body composition (estimated by 40K counting) were determined during each dietary regimen. During low N treatment, hay dry matter intake declined 2 kg/d, and supplement increased about .5 kg/d. Dry matter digestibility was not altered by N treatment. Protein and acid detergent fiber digestibilities decreased from 40 and 36% during adequate N to 20 and 2%, respectively, during low N. Fecal and urinary N also declined when cows were fed the low N diet. By the end of repletion, total intake, fiber, and protein digestibilities as well as N partition were similar to or exceeded those during adequate N intake. Body protein (N) loss was estimated by N balance to be about 3 kg compared with 8 kg by 40K counting. Body fat losses (32 kg) were large because of low energy digestibility and intake. Seven kilograms of body fat were regained during repletion, but there was no change in body protein

A question of balance: Kinetic balance for electrons and positrons

International Nuclear Information System (INIS)

Dyall, Kenneth G.

2012-01-01

Graphical abstract: Kinetic balance for both electrons and positrons is achieved by applying the correct relation for positive and negative energy states separately and then using the electron and positron eigensolutions from the separate diagonalizations of the Hamiltonian as a dual basis. Highlights: ► Kinetic balance for electrons and positrons is achieved in a dual atomic basis. ► Dual atomic balance alleviates, but does not eliminate, energy prolapse. ► Positron affinities converge quicker with basis set size with dual atomic balance. - Abstract: The kinetic balance criterion used in current relativistic basis set codes is satisfied by the electron solutions of the Dirac equation, but not the positron solutions. A proposal for applying kinetic balance to both sets of solutions is presented. The method is applied along with “normal” kinetic balance to one-electron systems, to investigate its possible relation to prolapse, and to the positron affinity of F − , to investigate the kinetic energy deficiency for positron solutions. The new method reduces but does not eliminate prolapse for energy-optimized basis sets, and provides faster and smoother convergence with basis set size for the positron affinity.

Utilization of urea-nitrogen-15 in ruminants

International Nuclear Information System (INIS)

Boda, K.; Varady, J.; Havassy, I.

1976-01-01

nitrogen recirculation and its balance. (author)

Effects of DanceSport on walking balance and standing balance among the elderly.

Science.gov (United States)

Sohn, Jeehoon; Park, Sung-Ha; Kim, Sukwon

2018-05-04

Dancesport is a popular activity among older adults who look for fun and fitness in Korea. Studies reported positive sociological and psychological effects of dancesport. But, little studies were performed to evaluate the effects of dancesport on balance performances. The objective of the present study was to evaluate the effects of dancesport for 15 weeks on walking balance and standing balance of older adults. Older adults regularly participated in the dancesport program 3 times a week for 15 weeks. The program included Rumba, Cha-cha-cha, and Jive. They exercised the prescribed dancesport at intermediate level for 50-60 mins for each time. A total 22 reflective markers were placed on the anatomical landmarks and 8 cameras were used to measure 3-D positions of participants. Also, center of pressure (COP) data were measured to analyze standing balance using a ground reaction board at 1200 Hz for 30 seconds. One-way analysis of variance (ANOVA) was performed to test the effects of 15 weeks of dancesport on walking balance and standing balance. The results suggested that, after 15 weeks of dancesport participation, older adults' walking balance (48.3 ± 20.3 cm2 vs 38.2 ± 18.2 cm2) and standing balance (COP area: 189.4 ± 85.4 mm2 vs 103.5 ± 55.4mm2, COP distance: 84.2 ± 34.4 cm vs 76.5 ± 21.4 cm) were significantly improved. Performing dancesport would require moving center of mass rapidly and frequently while maintaining posture. This may result in improving walking balance and standing balance in the present study. The study concluded that dancesport would be an effective exercise method in enhancing postural stability of older adults.

Governing processes for reactive nitrogen compounds in the European atmosphere

DEFF Research Database (Denmark)

Hertel, Ole; Skjøth, Carsten Ambelas; Reis, S.

2012-01-01

+)), oxidized nitrogen (NOy: nitrogen monoxide (NO) + nitrogen dioxide (NO2) and their reaction products) as well as organic nitrogen compounds (organic N). Pollution abatement strategies need to take into account the differences in the governing processes of these compounds when assessing their impact...... on ecosystem services, biodiversity, human health and climate. NOx (NO+NO2) emitted from traffic affects human health in urban areas where the presence of buildings increases the residence time in streets. In urban areas this leads to enhanced exposure of the population to NOx concentrations. NOx emissions.......5 and PM10 (mass of aerosols with an aerodynamic diameter of less than 2.5 and 10 mu m, respectively) with an impact on radiation balance as well as potentially on human health. Little is known quantitatively and qualitatively about organic N in the atmosphere, other than that it contributes a significant...

Regulation of nitrogen uptake and assimilation: Effects of nitrogen source and root-zone and aerial environment on growth and productivity of soybean

Science.gov (United States)

Raper, C. David, Jr.

1994-01-01

The interdependence of root and shoot growth produces a functional equilibrium as described in quantitative terms by numerous authors. It was noted that bean seedlings grown in a constant environment tended to have a constant distribution pattern of dry matter between roots and leaves characteristic of the set of environmental conditions. Disturbing equilibrium resulted in a change in relative growth of roots and leaves until the original ratio was restored. To define a physiological basis for regulation of nitrogen uptake within the balance between root and shoot activities, the authors combined a partioning scheme and a utilization priority assumption in which: (1) all carbon enters the plant through photosynthesis in leaves and all nitrogen enters the plant through active uptake by roots, (2) nitrogen uptake by roots and secretion into the xylem for transport to the shoots are active processes, (3) availability of exogenous nitrogen determines concentration of soluble carbohydrates within the roots, (4) leaves are a source and a sink for carbohydrates, and (5) the requirement for nitrogen by leaf growth is proportionally greater during initiation and early expansion than during later expansion.

Simulation of irrigation and nitrogen fertilization management of maize under edaphic conditions of south of Havana

International Nuclear Information System (INIS)

Lopez Seijas, Teresa; Cid, G.; Gonzalez, F.; Jorge, Y.; Chaterlan, Y.; Giralt, E.; Rodriguez, R.; Duennas, G.

1999-01-01

The main objective of this work is to validate the crop simulation model STICS for the soil and climate conditions of south of Havana, especially for the water and nitrogen balances on Maize crop on Ferralitic soil, For this purpose was used all the available information from field experiments carried out in the Experimental Stations of the Irrigation and Drainage and Soil Research Institutes, both on south of Havana, The comparison between the simulation and observed values showed a good fitness for the variables related to the crop water uptake, while for the soil water content when the root water uptake flux is minimum and the soil water redistribution flux is maximum wasn't good, The soil nitrogen balance was adjusted from the optimization of the parameters related to the mineralization velocity of soil organic nitrogen, Nevertheless is necessary to complete this study involving other climate conditions and water and nitrogen managements to define the optimum strategy for irrigation and fertilization of Maize crop on the studied conditions,

Comparing carbon to carbon: Organic and inorganic carbon balances across nitrogen fertilization gradients in rainfed vs. irrigated Midwest US cropland

Science.gov (United States)

Hamilton, S. K.; McGill, B.

2017-12-01

The top meter of the earth's soil contains about twice the amount of carbon than the atmosphere. Agricultural management practices influence whether a cropland soil is a net carbon source or sink. These practices affect both organic and inorganic carbon cycling although the vast majority of studies examine the former. We will present results from several rarely-compared carbon fluxes: carbon dioxide emissions and sequestration from lime (calcium carbonate) weathering, dissolved gases emitted from groundwater-fed irrigation, dissolved organic carbon (DOC) leaching to groundwater, and soil organic matter storage. These were compared in a corn-soybean-wheat rotation under no-till management across a nitrogen fertilizer gradient where half of the replicated blocks are irrigated with groundwater. DOC and liming fluxes are also estimated from a complementary study in neighboring plots comparing a gradient of management practices from conventional to biologically-based annuals and perennials. These studies were conducted at the Kellogg Biological Station Long Term Ecological Research site in Michigan where previous work estimated that carbon dioxide emissions from liming accounted for about one quarter of the total global warming impact (GWI) from no-till systems—our work refines that figure. We will present a first time look at the GWI of gases dissolved in groundwater that are emitted when the water equilibrates with the atmosphere. We will explore whether nitrogen fertilizer and irrigation increase soil organic carbon sequestration by producing greater crop biomass and residues or if they enhance microbial activity, increasing decomposition of organic matter. These results are critical for more accurately estimating how intensive agricultural practices affect the carbon balance of cropping systems.

Phosphorus and nitrogen in the eutrophication of waters

International Nuclear Information System (INIS)

Salonen, S.; Frisk, T.; Kaermeniemi, T.; Niemi, J.; Pitkaenen, H.; Silvo, K.; Vuoristo, H.

1992-01-01

This report is a summary of the contribution of nitrogen and phosphorus in the eutrophication process of inland and coastal waters. Special attention was paid to the mechanisms of these nutrients in regulating biological processes and to the methods available in estimating their effects in the eutrophication of water bodies. The report includes five chapters which are entitled: Introduction, which is a general background to the subject with special attention to the requirements of the Finnish Water Act. Phosphorus and nitrogen as factors regulating biological processes. The topics included are: definition of eutrophication, forms of phosphorus and nitrogen and their sources to inland and coastal waters, effects of these nutrients as growth factors of phytoplankton and macrophytes and consequences of eutrophication. Estimation of the effects of phosphorus and nitrogen. The topics discussed from the point of view of the tasks of the National Board of Waters and the Environment are: estimation of the effects of phosphorus and nitrogen in the planning and supervision of industry, fish farming, peat production, municipalities, agriculture and forestry. A brief state-of-the art of the research carried out in the National Board of Waters and the Environment is given. Methods of estimating the effects of phosphorus and nitrogen loading in waters. The topics are: relationships between phosphorus and nitrogen concentrations in waters, material balances, water quality models, classification of waters and different groups of organisms as indicators of water quality. Conclusions for the estimation of the effects of phosphorus and nitrogen in receiving waters

Carbon-nitrogen-water interactions: is model parsimony fruitful?

Science.gov (United States)

Puertes, Cristina; González-Sanchis, María; Lidón, Antonio; Bautista, Inmaculada; Lull, Cristina; Francés, Félix

2017-04-01

It is well known that carbon and nitrogen cycles are highly intertwined and both should be explained through the water balance. In fact, in water-controlled ecosystems nutrient deficit is related to this water scarcity. For this reason, the present study compares the capability of three models in reproducing the interaction between the carbon and nitrogen cycles and the water cycle. The models are BIOME-BGCMuSo, LEACHM and a simple carbon-nitrogen model coupled to the hydrological model TETIS. Biome-BGCMuSo and LEACHM are two widely used models that reproduce the carbon and nitrogen cycles adequately. However, their main limitation is that these models are quite complex and can be too detailed for watershed studies. On the contrary, the TETIS nutrient sub-model is a conceptual model with a vertical tank distribution over the active soil depth, dividing it in two layers. Only the input of the added litter and the losses due to soil respiration, denitrification, leaching and plant uptake are considered as external fluxes. Other fluxes have been neglected. The three models have been implemented in an experimental plot of a semi-arid catchment (La Hunde, East of Spain), mostly covered by holm oak (Quercus ilex). Plant transpiration, soil moisture and runoff have been monitored daily during nearly two years (26/10/2012 to 30/09/2014). For the same period, soil samples were collected every two months and taken to the lab in order to obtain the concentrations of dissolved organic carbon, microbial biomass carbon, ammonium and nitrate. In addition, between field trips soil samples were placed in PVC tubes with resin traps and were left incubating (in situ buried cores). Thus, mineralization and nitrification accumulated fluxes for two months, were obtained. The ammonium and nitrate leaching accumulated for two months were measured using ion-exchange resin cores. Soil respiration was also measured every field trip. Finally, water samples deriving from runoff, were collected

Changes in balance and joint position sense during a 12-day high altitude trek: The British Services Dhaulagiri medical research expedition.

Directory of Open Access Journals (Sweden)

Sarah B Clarke

Full Text Available Postural control and joint position sense are essential for safely undertaking leisure and professional activities, particularly at high altitude. We tested whether exposure to a 12-day trek with a gradual ascent to high altitude impairs postural control and joint position sense. This was a repeated measures observational study of 12 military service personnel (28±4 years. Postural control (sway velocity measured by a portable force platform during standing balance, a Sharpened Romberg Test and knee joint position sense were measured, in England (113m elevation and at 3 research camps (3619m, 4600m and 5140m on a 12-day high altitude trek in the Dhaulagiri region of Nepal. Pulse oximetry, and Lake Louise scores were also recorded on the morning and evening of each trek day. Data were compared between altitudes and relationships between pulse oximetry, Lake Louise score, and sway velocity were explored. Total sway velocity during standing balance with eyes open (p = 0.003, d = 1.9 and during Sharpened Romberg test with eyes open (p = 0.007, d = 1.6 was significantly greater at altitudes of 3619m and 5140m when compared with sea level. Anterior-posterior sway velocity during standing balance with eyes open was also significantly greater at altitudes of 3619m and 5140m when compared with sea level (p = 0.001, d = 1.9. Knee joint position sense was not altered at higher altitudes. There were no significant correlations between Lake Louise scores, pulse oximetry and postural sway. Despite a gradual ascent profile, exposure to 3619 m was associated with impairments in postural control without impairment in knee joint position sense. Importantly, these impairments did not worsen at higher altitudes of 4600 m or 5140 m. The present findings should be considered during future trekking expeditions when developing training strategies targeted to manage impairments in postural control that occur with increasing altitude.

Changes in balance and joint position sense during a 12-day high altitude trek: The British Services Dhaulagiri medical research expedition.

Science.gov (United States)

Clarke, Sarah B; Deighton, Kevin; Newman, Caroline; Nicholson, Gareth; Gallagher, Liam; Boos, Christopher J; Mellor, Adrian; Woods, David R; O'Hara, John P

2018-01-01

Postural control and joint position sense are essential for safely undertaking leisure and professional activities, particularly at high altitude. We tested whether exposure to a 12-day trek with a gradual ascent to high altitude impairs postural control and joint position sense. This was a repeated measures observational study of 12 military service personnel (28±4 years). Postural control (sway velocity measured by a portable force platform) during standing balance, a Sharpened Romberg Test and knee joint position sense were measured, in England (113m elevation) and at 3 research camps (3619m, 4600m and 5140m) on a 12-day high altitude trek in the Dhaulagiri region of Nepal. Pulse oximetry, and Lake Louise scores were also recorded on the morning and evening of each trek day. Data were compared between altitudes and relationships between pulse oximetry, Lake Louise score, and sway velocity were explored. Total sway velocity during standing balance with eyes open (p = 0.003, d = 1.9) and during Sharpened Romberg test with eyes open (p = 0.007, d = 1.6) was significantly greater at altitudes of 3619m and 5140m when compared with sea level. Anterior-posterior sway velocity during standing balance with eyes open was also significantly greater at altitudes of 3619m and 5140m when compared with sea level (p = 0.001, d = 1.9). Knee joint position sense was not altered at higher altitudes. There were no significant correlations between Lake Louise scores, pulse oximetry and postural sway. Despite a gradual ascent profile, exposure to 3619 m was associated with impairments in postural control without impairment in knee joint position sense. Importantly, these impairments did not worsen at higher altitudes of 4600 m or 5140 m. The present findings should be considered during future trekking expeditions when developing training strategies targeted to manage impairments in postural control that occur with increasing altitude.

Are we simplifying balance evaluation in adolescent idiopathic scoliosis?

Science.gov (United States)

Pasha, Saba; Baldwin, Keith

2018-01-01

Clinical evaluation of the postural balance in adolescent idiopathic scoliosis has been measured by sagittal vertical axis and frontal balance. The impact of the scoliotic deformity in three planes on balance has not been fully investigated. 47 right thoracic and left lumbar curves adolescent idiopathic scoliosis and 10 non-scoliotic controls were registered prospectively. 13 spinopelvic postural parameters were calculated from the 3-dimantional reconstructions of X-rays. 7 balance variables describing the position and sway of the center of pressure were recorded using a pressure mat. A regression analysis was used to predict sagittal vertical axis and frontal balance from the 7 balance variables. A canonical correlation analysis was performed between all the postural parameters and balance variables and the significant associations between the postural and balance variables were determined. sagittal vertical axis and frontal balance were not significantly associated with the position or sway of the center of pressure (p>0.05). Canonical correlation analysis showed significant associations between the postural variables in the 3 planes and center of pressure position (R 2 =0.81) and sway (R 2 =0.62), pbalance contributed to the postural balance in the cohort. The compensatory role of the pelvis and distal kyphosis in sagittal plane was underlined. Multidimensional analyses between the postural and balance variables showed the alignment of the thoracic, lumbar, and pelvis in the 3 planes, in addition to the global head-pelvic position impact on adolescent idiopathic scoliosis balance. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Effect of Balance Training by Tetraks Interactive Balance System on Balance and Fall Risk in Parkinson's Patients: A Report of Four Cases.

Science.gov (United States)

Balci, Nilay Çömük; Tonga, Eda; Gülşen, Mustafa

2013-09-01

This pilot study aimed to investigate the effect of balance training by Tetraks Interactive Balance System (TIBS) on balance and fall risk in patients with mild to moderate Parkinson's disease. Four patients with Parkinson's disease between the ages of 56 and 70 years (61.25±6.70) were applied balance training for 3 weeks by TIBS. Sociodemographic features and physical properties of the subjects were recorded. Their motor performance was evaluated by the Unified Parkinson's Disease Rating Scale (UPDRS), balance was measured using the Berg Balance Scale (BBS), Functional Reach Test (FRT), Timed Up and Go Test (TUG), and the Standing on One Leg Balance Test (SOL) and, their fall risks were evaluated by TIBS. Evaluations were performed twice, before and after treatment. Following training, Parkinson's patients showed improvements in UPDRS, TUG, BBS, FRT, SOL and fall risk. Balance training by TIBS has positive effects on balance and decreases fall risk in Parkinson's disease patients.

Oxidized Nitrogen Balance over 15 Months at Rural and Urban New York State Locations

Science.gov (United States)

Schwab, J. J.; Ninneman, M.; Marto, J.; Edgerton, E. S.; Blanchard, C. L.; Shaw, S. L.

2017-12-01

Continuous measurements of oxidized nitrogen species (NO, NO2, and HNO3), families of species (NOy, alkyl nitrates [or ANs], and peroxyacetyl nitrates [or PANs]), and particle nitrate (pNO3) were carried out for a fifteen-month period from August 2016 through October 2017 at two locations in New York State. The two sites were a rural research station at Pinnacle State Park in Addison, NY and an urban research station at Queens College in New York City. Four different chemiluminescence analyzers with various converters and denuders were employed to make these measurements. Instrumentation used for the study will be described, as well as some of the challenges created by combining data from these independent analyzers to address the oxidized nitrogen budget at the two sites. The Pinnacle State Park site often experiences quite clean air with low ppb levels of total NOy and a greater fraction of oxidized nitrogen products (NOz species). This contrasts with the urban Queens College location, which experiences stronger NOx sources. Seasonal differences in the NOx/NOy and NOz/NOy ratios, and the makeup of the NOz species, are also significant and will be explored in the presentation.

Does the position of the electron-donating nitrogen atom in the ring system influence the efficiency of a dye-sensitized solar cell? A computational study.

Science.gov (United States)

Biswas, Abul Kalam; Barik, Sunirmal; Das, Amitava; Ganguly, Bishwajit

2016-06-01

We have reported a number of new metal-free organic dyes (2-6) that have cyclic asymmetric benzotripyrrole derivatives as donor groups with peripheral nitrogen atoms in the ring, fluorine and thiophene groups as π-spacers, and a cyanoacrylic acid acceptor group. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were employed to examine the influence of the position of the donor nitrogen atom and π-conjugation on solar cell performance. The calculated electron-injection driving force (ΔG inject), electron-regeneration driving force (ΔG regen), light-harvesting efficiency (LHE), dipole moment (μ normal), and number of electrons transferred (∆q) indicate that dyes 3, 4, and 6 have significantly higher efficiencies than reference dye 1, which exhibits high efficiency. We also extended our comparison to some other reported dyes, 7-9, which have a donor nitrogen atom in the middle of the ring system. The computed results suggest that dye 6 possesses a higher incident photon to current conversion efficiency (IPCE) than reported dyes 7-9. Thus, the use of donor groups with peripheral nitrogen atoms appears to lead to more efficient dyes than those in which the nitrogen atom is present in the middle of the donor ring system. Graphical Abstract The locations of the nitrogen atoms in the donor groups in the designed dye molecules have an important influence on DSSC efficiency.

Benthic biogeochemical cycling, nutrient stoichiometry, and carbon and nitrogen mass balances in a eutrophic freshwater bay

Science.gov (United States)

Klump, J.V.; Fitzgerald, S.A.; Waplesa, J.T.

2009-01-01

Green Bay, while representing only ,7% of the surface area and ??1.4% of the volume of Lake Michigan, contains one-third of the watershed of the lake, and receives approximately one-third of the total nutrient loading to the Lake Michigan basin, largely from the Fox River at the southern end of the bay. With a history of eutrophic conditions dating back nearly a century, the southern portion of the bay behaves as an efficient nutrient and sediment trap, sequestering much of the annual carbon and nitrogen input within sediments accumulating at up to 1 cm per year. Depositional fluxes of organic matter varied from ??0.1 mol C m-2 yr-1 to >10 mol C m-2 yr-1 and were both fairly uniform in stoichiometric composition and relatively labile. Estimates of benthic recycling derived from pore-water concentration gradients, whole-sediment incubation experiments, and deposition-burial models of early diagenesis yielded an estimated 40% of the carbon and 50% of the nitrogen recycled back into the overlying water. Remineralization was relatively rapid with ??50% of the carbon remineralized within <15 yr of deposition, and a mean residence time for metabolizable carbon and nitrogen in the sediments of 20 yr. On average, organic carbon regeneration occurred as 75% CO2, 15% CH4, and 10% dissolved organic carbon (DOC). Carbon and nitrogen budgets for the southern bay were based upon direct measurements of inputs and burial and upon estimates of export and production derived stoichiometrically from a coupled phosphorus budget. Loadings of organic carbon from rivers were ??3.7 mol m-2 yr-1, 80% in the form of DOC and 20% as particulate organic carbon. These inputs were lost through export to northern Green Bay and Lake Michigan (39%), through sediment burial (26%), and net CO2 release to the atmosphere (35%). Total carbon input, including new production, was 4.54 mol m-2 C yr-1, equivalent to ??10% of the gross annual primary production. Nitrogen budget terms were less well quantified

Integrasi Personal Balanced Scorecard, Psikologi Integral, dan Positive Organization Behaviour/ Scholarship sebagai Pendekatan Komprehensif di Perusahaan/Organisasi

Directory of Open Access Journals (Sweden)

Nurlaila Effendy

2017-07-01

Full Text Available Kinerja suatu organisasi diukur dari physical assets, financial capital dan human capital. Organisasi memerlukan sistem yang tepat dalam meningkatkan kinerja.Tujuan Performance Management System yang diterapkan dalam organisasi adalah untuk mengoptimalkan potensi individu, tim, pemimpin, dan organisasi. Pendekatan komprehensif diperlukan untuk dapat mengoptimalkan potensi dan pencapaian kinerja yang optimal.PBSC adalahperformance management system dengan pendekatan perspektif finance dan non finance serta mengintegrasikan dengan formulasi strategi (visi, misi organisasi, tujuan organisasi dengan tujuan departemen dan tujuan karyawan. PBSC adalah konsep baru dengan pendekatan personal,baik terkait perusahaan maupun bukan terkait pekerjaansebagai ukuran diri. Pengembangan suatu organisasi yang terintegrasi adalah adanya kesadaran individu-individu dalam organisasi yang memunculkan personal meaning atau kebermaknaan diri di dalam organisasi, sehingga akan membentuk budaya organisasi dan iklim organisasi yang efektif dan harmoni. Penerapan Positive Organization Behavior dan Positive Organization Scholarship pada organisasi akan membangun Positive Emotional Climate dan Organization Relational Strength. Pendekatan secara integratif antara Personal Balance Scorecard, Positive Organizational Scholarship, Positive Organizational Behavior dan Psikologi Integral akan memperkuat kinerja organisasi dan memiliki kesempatan menuju organisasi Positif . Individu dalam organisasi akan memiliki vitalitas dan mengalami flow, dan organisasimemiliki flourishing

META-ANALYSIS OF NITROGEN REMOVAL IN RIPARIAN BUFFERS

Science.gov (United States)

Riparian buffer zones, the vegetated region adjacent to streams and wetlands, are thought to be effective at intercepting and controlling nitrogen loads entering water bodies. Riparian buffer width may be positively related to nitrogen removal effectiveness by influencing nitrog...

Relationships Between Simple Toe Elevation Angle in the Standing Position and Dynamic Balance and Fall Risk Among Community-Dwelling Older Adults.

Science.gov (United States)

Takatori, Katsuhiko; Matsumoto, Daisuke

2015-10-01

To investigate the relationships between toe elevation ability in the standing position and dynamic balance and fall risk among community-dwelling older adults. Cross-sectional survey. General community. Community-dwelling older adults (N = 287). Toe elevation angles in the standing position. Intra-rater and inter-rater reliability of measurements of the toe elevation angle was high (internal coefficient of correlation [ICC] (1,2) = 0.94 for the former and ICC (2,1) = 0.90 for the latter). Significant correlations were found between the toe elevation angle and age (r = -0.20, P fall in the previous 6 months had a significantly lower toe elevation angle compared with subjects who did not experience a fall (t = 2.19, P balance ability and appears to be a simple screening test for fall risk in community-dwelling older adults. Copyright © 2015 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Balancing energy strategies in electricity portfolio management

International Nuclear Information System (INIS)

Moeller, Christoph; Rachev, Svetlozar T.; Fabozzi, Frank J.

2011-01-01

Traditional management of electricity portfolios is focused on the day-ahead market and futures of longer maturity. Within limits, market participants can however also resort to the balancing energy market to close their positions. In this paper, we determine strategic positions in the balancing energy market and identify corresponding economic incentives in an analysis of the German balancing energy demand. We find that those strategies allow an economically optimal starting point for real-time balancing and create a marketplace for flexible capacity that is more open than alternative marketplaces. The strategies we proffer in this paper we believe will contribute to an effective functioning of the electricity market. (author)

Use of 15N methodology to assess biological nitrogen fixation

International Nuclear Information System (INIS)

Hardarson, G.

1990-01-01

One of the most important characteristics of legumes are their ability in symbiosis with Rhizobium bacteria to fix atmospheric nitrogen for growth. For proper management and a full realization of the benefits of this plant-microbial association, it is necessary to estimate how much nitrogen is fixed under different conditions in the field. It is only after this is known that various factors can be manipulated so as to increase the amount and proportion of N a plant derives from biological fixation. A suitable method for accurately measuring the amount of N crops derive from fixation is therefore an important requirement in any programme aimed at maximizing biological nitrogen fixation. There are several methods available to measure N 2 fixation (Bergersen, 1980) based on (1) increment in N yield and plant growth, (2) nitrogen balance (3) acetylene reduction and (4) the use of isotopes of N. Only isotopic methods will be illustrated here. 20 refs, 2 figs, 9 tabs

A new mathematical model for nitrogen gas production with special emphasis on the role of attached growth media in anammox hybrid reactor.

Science.gov (United States)

Tomar, Swati; Gupta, Sunil Kumar

2015-11-01

The present study emphasised on the development of new mathematical models based on mass balance and stoichiometry of nitrogen removal in anammox hybrid reactor (AHR). The performance of AHR at varying hydraulic retention times (HRTs) and nitrogen loading rates (NLRs) revealed that nitrogen removal efficiency (NRE) increases with increase in HRT and was found optimal (89 %) at HRT of 2 days. Mass balance of nitrogen revealed that major fraction (74.1 %) of input nitrogen is converted into N2 gas followed by 11.2 % utilised in biomass synthesis. Attached growth media (AGM) in AHR contributed to an additional 15.4 % ammonium removal and reduced the sludge washout rate by 29 %. This also enhanced the sludge retention capacity of AHR and thus minimised the formation of nitrate in the treated effluent, which is one of the bottlenecks of anammox process. Process kinetics was also studied using various mathematical models. The mass balance model derived from total nitrogen was found most precise and predicted N2 gas with least error (1.68 ± 4.44 %). Model validation for substrate removal kinetics dictated comparatively higher correlation for Grau second-order model (0.952) than modified Stover-Kincannon model (0.920). The study concluded that owing to features of high biomass retention, less nitrate formation and consistently higher nitrogen removal efficiency, this reactor configuration is techno-economically most efficient and viable. The study opens the door for researchers and scientists for pilot-scale testing of AHR leading to its wide industrial application.

Predicting unsaturated zone nitrogen mass balances in agricultural settings of the United States

Science.gov (United States)

Nolan, Bernard T.; Puckett, Larry J.; Ma, Liwang; Green, Christopher T.; Bayless, E. Randall; Malone, Robert W.

2009-01-01

Unsaturated zone N fate and transport were evaluated at four sites to identify the predominant pathways of N cycling: an almond [Prunus dulcis (Mill.) D.A. Webb] orchard and cornfield (Zea mays L.) in the lower Merced River study basin, California; and corn–soybean [Glycine max (L.) Merr.] rotations in study basins at Maple Creek, Nebraska, and at Morgan Creek, Maryland. We used inverse modeling with a new version of the Root Zone Water Quality Model (RZWQM2) to estimate soil hydraulic and nitrogen transformation parameters throughout the unsaturated zone; previous versions were limited to 3-m depth and relied on manual calibration. The overall goal of the modeling was to derive unsaturated zone N mass balances for the four sites. RZWQM2 showed promise for deeper simulation profiles. Relative root mean square error (RRMSE) values for predicted and observed nitrate concentrations in lysimeters were 0.40 and 0.52 for California (6.5 m depth) and Nebraska (10 m), respectively, and index of agreement (d) values were 0.60 and 0.71 (d varies between 0 and 1, with higher values indicating better agreement). For the shallow simulation profile (1 m) in Maryland, RRMSE and d for nitrate were 0.22 and 0.86, respectively. Except for Nebraska, predictions of average nitrate concentration at the bottom of the simulation profile agreed reasonably well with measured concentrations in monitoring wells. The largest additions of N were predicted to come from inorganic fertilizer (153–195 kg N ha−1 yr−1 in California) and N fixation (99 and 131 kg N ha−1 yr−1 in Maryland and Nebraska, respectively). Predicted N losses occurred primarily through plant uptake (144–237 kg N ha−1 yr−1) and deep seepage out of the profile (56–102 kg N ha−1 yr−1). Large reservoirs of organic N (up to 17,500 kg N ha−1 m−1 at Nebraska) were predicted to reside in the unsaturated zone, which has implications for potential future transfer of nitrate to groundwater.

Balance control in older adults

NARCIS (Netherlands)

Van Dieën, Jaap H.; Pijnappels, Mirjam

2017-01-01

To avoid falls during everyday movements, we need to maintain balance, i.e., control the position of our body's center of mass relative to our base of support. The balance control system comprises sensory subsystems, their afferent nerves, an extensive brain network, and the motor system.

[Interactions of straw, nitrogen fertilizer and bacterivorous nematodes on soil labile carbon and nitrogen and greenhouse gas emissions].

Science.gov (United States)

Zhang, Teng-Hao; Wang, Nan; Liu, Man-Qiang; Li, Fang-Hui; Zhu, Kang-Li; Li, Hui-Xin; Hu, Feng

2014-11-01

A 3 x 2 factorial design of microcosm experiment was conducted to investigate the interactive effects of straw, nitrogen fertilizer and bacterivorous nematodes on soil microbial biomass carbon (C(mic)) and nitrogen (N(mic)), dissolved organic carbon (DOC) and nitrogen (DON), mineral nitrogen (NH(4+)-N and NO(3-)-N), and greenhouse gas (CO2, N2O and CH4) emissions. Results showed that straw amendment remarkably increased the numbers of bacterivorous nematodes and the contents of Cmic and Nmic, but Cmic and Nmic decreased with the increasing dose of nitrogen fertilization. The effects of bacterivorous nematodes strongly depended on either straw or nitrogen fertilization. The interactions of straw, nitrogen fertilization and bacterivorous nematodes on soil DOC, DON and mineral nitrogen were strong. Straw and nitrogen fertilization increased DOC and mineral nitrogen contents, but their influences on DON depended on the bacterivorous nematodes. The DOC and mineral nitrogen were negatively and positively influenced by the bacterivorous nematodes, re- spectively. Straw significantly promoted CO2 and N2O emissions but inhibited CH4 emission, while interactions between nematodes and nitrogen fertilization on emissions of greenhouse gases were obvious. In the presence of straw, nematodes increased cumulative CO2 emissions with low nitrogen fertilization, but decreased CO2 and N2O emissions with high nitrogen fertilization on the 56th day after incubation. In summary, mechanical understanding the soil ecological process would inevitably needs to consider the roles of soil microfauna.

Effects of experimental warming and nitrogen addition on soil respiration and CH4 fluxes from crop rotations of winter wheat–soybean/fallow

DEFF Research Database (Denmark)

Liu, L; Hu, C; Yang, P

2015-01-01

Soil respiration and CH4 emissions play a significant role in the global carbon balance. However, in situ studies in agricultural soils on responses of soil respiration and CH4 fluxes to climate warming are still sparse, especially from long-term studies with year-round heating. A warming...... by affecting soil NH4 concentration. Across years, CH4 emissions were negatively correlated with soil temperature in N1 treatment. Soil respiration showed clear seasonal fluctuations, with the largest emissions during summer and smallest in winter. Warming and nitrogen fertilization had no significant effects...... on total cumulative soil CO2 fluxes. Soil respiration was positively correlated with microbial biomass C, and microbial biomass C was not affected significantly by warming or nitrogen addition. The lack of significant effects of warming on soil respiration may have resulted from: (1) warming-induced soil...

Successive ionization of positive ions of carbon and nitrogen by electron bombardment

International Nuclear Information System (INIS)

Donets, E.D.; Ilyushchenko, V.I.

Experimental studies of deep ionization of heavy ions are described. The applications of such studies in atomic physics, plasma physics and space physics are discussed. Investigations using intersecting ion-electron beams, shifted beams and ion trap sources are described, and data are presented for multi-charged ions of carbon, oxygen and nitrogen. A detailed description of the development of the IEL (electron beam ionizer) source, and the KRION (cryogenic version) source is given, and further data for the multiple ionization of carbon and nitrogen are given for charge states up to C 6+ and N 7+ . The advantages and disadvantages of the KRION source are discussed, and preliminary studies of a new torroidal ion trap source (HIRAC) are presented. (11 figs, 57 refs) (U.S.)

Changes in nitrogen budget and potential risk to the environment over 20years (1990-2010) in the agroecosystems of the Haihe Basin, China.

Science.gov (United States)

Zheng, Mengmeng; Zheng, Hua; Wu, Yingxia; Xiao, Yi; Du, Yihua; Xu, Weihua; Lu, Fei; Wang, Xiaoke; Ouyang, Zhiyun

2015-02-01

The nitrogen balance can serve as an indicator of the risk to the environment of nitrogen loss from agricultural land. To investigate the temporal and spatial changes in agricultural nitrogen application and its potential threat to the environment of the Haihe Basin in China, we used a database of county-level agricultural statistics to calculate agricultural nitrogen input, output, surplus intensity, and use efficiency. Chemical fertilizer nitrogen input increased by 51.7% from 1990 to 2000 and by 37.2% from 2000 to 2010, concomitant with increasing crop yields. Simultaneously, the nitrogen surplus intensity increased by 53.5% from 1990 to 2000 and by 16.5% from 2000 to 2010, presenting a continuously increased environmental risk. Nitrogen use efficiency decreased from 0.46 in 1990 to 0.42 in 2000 and remained constant at 0.42 in 2010, partly due to fertilizer composition and type improvement. This level indicates that more than half of nitrogen inputs are lost in agroecosystems. Our results suggest that although the improvement in fertilizer composition and types has partially offset the decrease in nitrogen use efficiency, the environmental risk has still increased gradually over the past 20 years, along with the increase in crop yields and nitrogen application. It is important to achieve a better nitrogen balance through more effective management to significantly reduce the environmental risk, decrease nitrogen surplus intensity, and increase nitrogen use efficiency without sacrificing crop yields. Copyright © 2014. Published by Elsevier B.V.

SOIL NITROGEN TRANSFORMATIONS AND ROLE OF LIGHT FRACTION ORGANIC MATTER IN FOREST SOILS

Science.gov (United States)

Depletion of soil organic matter through cultivation may alter substrate availability for microbes, altering the dynamic balance between nitrogen (N) immobilization and mineralization. Soil light fraction (LF) organic matter is an active pool that decreases upon cultivation, and...

Positivity and well-being among community-residing elders and nursing home residents: what is the optimal affect balance?

Science.gov (United States)

Meeks, Suzanne; Van Haitsma, Kimberly; Kostiwa, Irene; Murrell, Stanley A

2012-07-01

To explore whether a ratio of positive to negative affect, from the work of Fredricksen and Losada, could predict high levels of well-being in elderly samples and especially in nursing home residents despite multiple chronic health conditions, consonant with Ryff and Singer's notion of "flourishing under fire." We used two samples: a probability sample of community-residing elders and a sample from nursing homes. We calculated ratios of positive to negative affect in each sample and measured well-being with social interaction, mental health, life satisfaction, and general well-being. The positivity ratio of 2.9 differentiated high levels of well-being in both the samples, as in previous research on younger samples. Although we expected the positivity ratio to perform less well among nursing home residents, we found that it differentiated residents with high well-being just as well as in the community sample. The ability to regulate positive affect to maintain a relative ratio of positive over negative affect appears to be an important aspect of successful adjustment in late life. Further research is needed on objective indicators of quality of life and on whether intra-individual shifts in affect balance are coupled with shifts in indicators of positive mental health.

Enzymology under global change: organic nitrogen turnover in alpine and sub-Arctic soils

NARCIS (Netherlands)

Weedon, J.T.; Aerts, R.; Kowalchuk, G.A.; van Bodegom, P.M.

2011-01-01

Understanding global change impacts on the globally important carbon storage in alpine, Arctic and sub-Arctic soils requires knowledge of the mechanisms underlying the balance between plant primary productivity and decomposition. Given that nitrogen availability limits both processes, understanding

Enzymology under global change: organic nitrogen turnover in alpine and sub-Arctic soils.

NARCIS (Netherlands)

Weedon, J.T.; Aerts, R.; Kowalchuk, G.A.; van Bodegom, P.M.

2011-01-01

Understanding global change impacts on the globally important carbon storage in alpine, Arctic and sub-Arctic soils requires knowledge of the mechanisms underlying the balance between plant primary productivity and decomposition. Given that nitrogen availability limits both processes, understanding

Modeling effects of hydrological changes on the carbon and nitrogen balance of oak in floodplains.

Science.gov (United States)

Pietsch, Stephan A; Hasenauer, Hubert; Kucera, Jiŕi; Cermák, Jan

2003-08-01

We extended the applicability of the ecosystem model BIOME-BGC to floodplain ecosystems to study effects of hydrological changes on Quercus robur L. stands. The extended model assesses floodplain peculiarities, i.e., seasonal flooding and water infiltration from the groundwater table. Our interest was the tradeoff between (a). maintaining regional applicability with respect to available model input information, (b). incorporating the necessary mechanistic detail and (c). keeping the computational effort at an acceptable level. An evaluation based on observed transpiration, timber volume, soil carbon and soil nitrogen content showed that the extended model produced unbiased results. We also investigated the impact of hydrological changes on our oak stands as a result of the completion of an artificial canal network in 1971, which has stopped regular springtime flooding. A comparison of the 11 years before versus the 11 years after 1971 demonstrated that the hydrological changes affected mainly the annual variation across years in leaf area index (LAI) and soil carbon and nitrogen sequestration, leading to stagnation of carbon and nitrogen stocks, but to an increase in the variance across years. However, carbon sequestration to timber was unaffected and exhibited no significant change in cross-year variation. Finally, we investigated how drawdown of the water table, a general problem in the region, affects modeled ecosystem behavior. We found a further amplification of cross-year LAI fluctuations, but the variance in soil carbon and nitrogen stocks decreased. Volume increment was unaffected, suggesting a stabilization of the ecosystem two decades after implementation of water management measures.

Energy balance and stability

International Nuclear Information System (INIS)

Hammer, R.

1982-01-01

The energy balance of the outer atmospheres of solarlike stars is discussed. The energy balance of open coronal regions is considered, discussing the construction and characteristics of models of such regions in some detail. In particular, the temperature as a function of height is considered, as are the damping length dependence of the global energy balance in the region between the base of the transition region and the critical point, and the effects of changing the amount of coronal heating, the stellar mass, and the stellar radius. Models of coronal loops are more briefly discussed. The chromosphere is then included in the discussion of the energy balance, and the connection between global energy balance and global thermal stability is addressed. The observed positive correlations between the chromospheric and coronal energy losses and the pressure of the transition region is qualitatively explained

Comparisons of soil nitrogen mass balances for an ombrotrophic bog and a minerotrophic fen in northern Minnesota

Science.gov (United States)

Brian H. Hill; Terri M. Jicha; LaRae L.P. Lehto; Colleen M. Elonen; Stephen D. Sebestyen; Randy Kolka

2016-01-01

Wecompared nitrogen (N) storage and flux in soils froman ombrotrophic bogwith that of a minerotrophic fen to quantify the differences in N cycling between these two peatlands types in northernMinnesota (USA). Precipitation, atmospheric deposition, and bog and fen outflowswere analyzed for nitrogen species. Upland and peatland soil sampleswere analyzed for N content,...

Economic effect of reducing nitrogen and phosphorus mass balance on Wisconsin and Québec dairy farms.

Science.gov (United States)

Pellerin, D; Charbonneau, E; Fadul-Pacheco, L; Soucy, O; Wattiaux, M A

2017-10-01

Our objective was to explore the trade-offs between economic performance (farm net income, FNI) and environmental outcomes (whole-farm P and N balances) of dairy farms in Wisconsin (WI; United States) and Québec (QC; Canada). An Excel-based linear program model (N-CyCLES; nutrient cycling: crops, livestock, environment, and soil) was developed to optimize feeding, cropping, and manure management as a single unit of management. In addition to FNI, P and N balances model outputs included (1) the mix of up to 9 home-grown and 17 purchased feeds for up to 5 animal groups, (2) the mix of up to 5 crop rotations in up to 5 land units and c) the mix of up to 7 fertilizers (solid and liquid manure and 5 commercial fertilizers) to allocate in each land unit. The model was parameterized with NRC nutritional guidelines and regional nutrient management planning rules. Simulations were conducted on a typical WI farm of 107 cows and 151 ha of cropland and, a Southern QC farm of 87 cows and 142 ha of cropland and all results were expressed per kg of fat- and protein-corrected milk (FPCM). In absence of constraints on P and N balances, maximum FNI was 0.12 and 0.11 $/kg of FPCM for WI and QC, respectively, with P and N balances of 1.05 and 14.29 g/kg of FPCM in WI but 0.60 and 15.70 g/kg of FPCM in QC. The achievable reduction (balance at maximum FNI minus balance when the simulation objective was to minimize P or N balance) was 0.31 and 0.54 g of P/kg of FPCM (29 and 89% reduction), but 2.37 and 3.31 g of N/kg of FPCM (17 and 24% reduction) in WI and QC, respectively. Among other factors, differences in animal unit per hectare and reliance on biological N fixation may have contributed to lower achievable reductions of whole-farm balances in WI compared with QC. Subsequent simulations to maximize FNI under increasing constraints on nutrient balances revealed that it was possible to reduce P balance, N balance, and both together by up to 33% without a substantial effect on FNI

Flux balance analysis of ammonia assimilation network in E. coli predicts preferred regulation point.

Science.gov (United States)

Wang, Lu; Lai, Luhua; Ouyang, Qi; Tang, Chao

2011-01-25

Nitrogen assimilation is a critical biological process for the synthesis of biomolecules in Escherichia coli. The central ammonium assimilation network in E. coli converts carbon skeleton α-ketoglutarate and ammonium into glutamate and glutamine, which further serve as nitrogen donors for nitrogen metabolism in the cell. This reaction network involves three enzymes: glutamate dehydrogenase (GDH), glutamine synthetase (GS) and glutamate synthase (GOGAT). In minimal media, E. coli tries to maintain an optimal growth rate by regulating the activity of the enzymes to match the availability of the external ammonia. The molecular mechanism and the strategy of the regulation in this network have been the research topics for many investigators. In this paper, we develop a flux balance model for the nitrogen metabolism, taking into account of the cellular composition and biosynthetic requirements for nitrogen. The model agrees well with known experimental results. Specifically, it reproduces all the (15)N isotope labeling experiments in the wild type and the two mutant (ΔGDH and ΔGOGAT) strains of E. coli. Furthermore, the predicted catalytic activities of GDH, GS and GOGAT in different ammonium concentrations and growth rates for the wild type, ΔGDH and ΔGOGAT strains agree well with the enzyme concentrations obtained from western blots. Based on this flux balance model, we show that GS is the preferred regulation point among the three enzymes in the nitrogen assimilation network. Our analysis reveals the pattern of regulation in this central and highly regulated network, thus providing insights into the regulation strategy adopted by the bacteria. Our model and methods may also be useful in future investigations in this and other networks.

Flux balance analysis of ammonia assimilation network in E. coli predicts preferred regulation point.

Directory of Open Access Journals (Sweden)

Lu Wang

Full Text Available Nitrogen assimilation is a critical biological process for the synthesis of biomolecules in Escherichia coli. The central ammonium assimilation network in E. coli converts carbon skeleton α-ketoglutarate and ammonium into glutamate and glutamine, which further serve as nitrogen donors for nitrogen metabolism in the cell. This reaction network involves three enzymes: glutamate dehydrogenase (GDH, glutamine synthetase (GS and glutamate synthase (GOGAT. In minimal media, E. coli tries to maintain an optimal growth rate by regulating the activity of the enzymes to match the availability of the external ammonia. The molecular mechanism and the strategy of the regulation in this network have been the research topics for many investigators. In this paper, we develop a flux balance model for the nitrogen metabolism, taking into account of the cellular composition and biosynthetic requirements for nitrogen. The model agrees well with known experimental results. Specifically, it reproduces all the (15N isotope labeling experiments in the wild type and the two mutant (ΔGDH and ΔGOGAT strains of E. coli. Furthermore, the predicted catalytic activities of GDH, GS and GOGAT in different ammonium concentrations and growth rates for the wild type, ΔGDH and ΔGOGAT strains agree well with the enzyme concentrations obtained from western blots. Based on this flux balance model, we show that GS is the preferred regulation point among the three enzymes in the nitrogen assimilation network. Our analysis reveals the pattern of regulation in this central and highly regulated network, thus providing insights into the regulation strategy adopted by the bacteria. Our model and methods may also be useful in future investigations in this and other networks.

Two negative regulatory systems of root nodule symbiosis - how are symbiotic benefits and costs balanced?

Science.gov (United States)

Nishida, Hanna; Suzaki, Takuya

2018-05-30

Root nodule symbiosis is one of the best-characterized mutualistic relationships between plants-microbes symbiosis, where mainly leguminous species can obtain nitrogen sources fixed by nitrogen-fixing rhizobia through the formation of symbiotic organs root nodules. In order to drive this symbiotic process, plants need to provide carbon sources that should be used for their growth. Therefore, a balance between the benefits of obtaining nitrogen sources and the costs of losing carbon sources needs to be maintained during root nodule symbiosis. Plants have developed at least two negative regulatory systems of root nodule symbiosis. One strategy involves the regulation of nodule number in response to rhizobial infection. For this regulation, a systemic long-range signaling between roots and shoots called autoregulation of nodulation has a pivotal role. Another strategy involves the regulation of root nodule symbiosis in response to nitrate, the most abundant form of nitrogen nutrients in the soil. Recent studies indicate that a long-distance signaling is shared between the two strategies, where NIN and NRSYM1, two paralogous RWP-RK transcription factors, can activate the production of nodulation-related CLE peptides in response to different inputs. Here, we give an overview of such progress in our understanding of molecular mechanisms relevant to the control of the symbiotic balance, including their biological significance.

The Association of Flexibility, Balance, and Lumbar Strength with Balance Ability: Risk of Falls in Older Adults

Directory of Open Access Journals (Sweden)

Emilio J. Martínez-López Emilio

2014-06-01

Full Text Available The purpose of the present study was to determine the effects of a proprioceptive training program on older adults, as well as to analyze the association between flexibility, balance and lumbar strength (physical fitness test with balance ability and fall risk (functional balance tests. This study was a controlled, longitudinal trial with a 12-week follow-up period. Subjects from a population of older adults were allocated to the intervention group (n = 28 or to the usual care (control group (n = 26. Subjects performed proprioceptive training twice weekly (6 specific exercises with Swiss ball and BOSU. Each session included 50 minutes (10 minutes of warm-up with slow walk, 10 minutes of mobility and stretching exercises, 30 minutes of proprioceptive exercises. The outcome variables were physical fitness (lower-body flexibility, hip-joint mobility, dynamic balance, static balance, and lumbar strength and functional balance (Berg scale and Tinetti test. The experimental group obtained significantly higher values than the control group in lower-body flexibility, dynamic balance, and lumbar strength (p = 0.019, p < 0.001, and p = 0.034 respectively. Hip-joint mobility, dynamic balance, and lumbar strength were positively associated with balance ability (p < 0.001, p < 0.001, and p = 0.014, respectively and the prevention of falls (p = 0.001, p < 0.001, and p = 0.017 respectively. These findings suggest that a 12-week proprioception program intervention (twice a week significantly improves flexibility, balance, and lumbar strength in older adults. Hip-joint mobility, dynamic balance and lumbar strength are positively associated to balance ability and the risk of falls in older adults. This proprioceptive training does not show a significant improvement in hip-joint mobility or static balance.

Energy-positive wastewater treatment and desalination in an integrated microbial desalination cell (MDC)-microbial electrolysis cell (MEC)

Science.gov (United States)

Li, Yan; Styczynski, Jordyn; Huang, Yuankai; Xu, Zhiheng; McCutcheon, Jeffrey; Li, Baikun

2017-07-01

Simultaneous removal of nitrogen in municipal wastewater, metal in industrial wastewater and saline in seawater was achieved in an integrated microbial desalination cell-microbial electrolysis cell (MDC-MEC) system. Batch tests showed that more than 95.1% of nitrogen was oxidized by nitrification in the cathode of MDC and reduced by heterotrophic denitrification in the anode of MDC within 48 h, leading to the total nitrogen removal rate of 4.07 mg L-1 h-1. Combining of nitrogen removal and desalination in MDC effectively solved the problem of pH fluctuation in anode and cathode, and led to 63.7% of desalination. Power generation of MDC (293.7 mW m-2) was 2.9 times higher than the one without salt solution. The electric power of MDC was harvested by a capacitor circuit to supply metal reduction in a MEC, and 99.5% of lead (II) was removed within 48 h. A kinetic MDC model was developed to elucidate the correlation of voltage output and desalination efficiency. Ratio of wastewater and sea water was calculated for MDC optimal operation. Energy balance of nutrient removal, metal removal and desalination in the MDC-MEC system was positive (0.0267 kW h m-3), demonstrating the promise of utilizing low power output of MDCs.

Homogeneous dihydroxylation of olefins catalyzed by OsO(4)(2-) immobilized on a dendritic backbone with a tertiary nitrogen at its core position.

Science.gov (United States)

Fujita, Ken-Ichi; Inoue, Kensuke; Tsuchimoto, Teruhisa; Yasuda, Hiroyuki

2012-01-01

OsO(4)(2-) immobilized on a poly(benzyl ether) dendrimer with a tertiary nitrogen at its core position efficiently catalyzed the homogeneous dihydroxylation of olefins with a low level of osmium leaching. The dendritic osmium catalyst could be applied to the wide range of olefins. Furthermore, the dendritic osmium catalyst was recovered by reprecipitation and then reused up to five times.

Tapered fiber coupling of single photons emitted by a deterministically positioned single nitrogen vacancy center

Energy Technology Data Exchange (ETDEWEB)

Liebermeister, Lars, E-mail: lars.liebermeister@physik.uni-muenchen.de; Petersen, Fabian; Münchow, Asmus v.; Burchardt, Daniel; Hermelbracht, Juliane; Tashima, Toshiyuki [Fakultät für Physik, Ludwig-Maximilians-Universität München, 80799 München (Germany); Schell, Andreas W.; Benson, Oliver [Institut für Physik, Humboldt-Universität zu Berlin, 12489 Berlin (Germany); Meinhardt, Thomas; Krueger, Anke [Institut für Organische Chemie, Universität Würzburg, 97074 Würzburg (Germany); Wilhelm Conrad Roentgen Research Center for Complex Materials Systems, Universität Würzburg, 97074 Würzburg (Germany); Stiebeiner, Ariane; Rauschenbeutel, Arno [Atominstitut, Technische Universität Wien, 1020 Wien (Austria); Weinfurter, Harald; Weber, Markus, E-mail: markusweber@lmu.de [Fakultät für Physik, Ludwig-Maximilians-Universität München, 80799 München (Germany); Max-Planck-Institut für Quantenoptik, 85748 Garching (Germany)

2014-01-20

A diamond nano-crystal hosting a single nitrogen vacancy (NV) center is optically selected with a confocal scanning microscope and positioned deterministically onto the subwavelength-diameter waist of a tapered optical fiber (TOF) with the help of an atomic force microscope. Based on this nano-manipulation technique, we experimentally demonstrate the evanescent coupling of single fluorescence photons emitted by a single NV-center to the guided mode of the TOF. By comparing photon count rates of the fiber-guided and the free-space modes and with the help of numerical finite-difference time domain simulations, we determine a lower and upper bound for the coupling efficiency of (9.5 ± 0.6)% and (10.4 ± 0.7)%, respectively. Our results are a promising starting point for future integration of single photon sources into photonic quantum networks and applications in quantum information science.

Study of plasma characteristics in the cathode regime of a nitrogen glow discharge

International Nuclear Information System (INIS)

Margulis, Alvaro

1987-01-01

This research thesis reports the study of the cathode region, cathodic sheath and negative glow, of a nitrogen glow discharge. The author first presents general data regarding glow discharges, a description of the experimental installation, and measurements of discharge balancing. In the next part, he precisely describes spectroscopic methods, and the implementation of diagnoses from an experimental point of view as well as in terms of space resolution. Results are then presented and interpreted. Measurements concern space distributions of excited species, the determination of axial and radial concentrations of nitrogen ions, axial variations of rotational temperatures of the different species and variations of nitrogen ion vibrational temperature. The laser optogalvanic effect on the nitrogen molecular ion is resolved in time, and compared with the result of a theoretical model based on the mobility difference between the different nitrogen ions. Finally, the author compares experimental results on ion profiles along the discharge axis with results obtained with theoretical models [fr

Plant physiological responses to hydrologically mediated changes in nitrogen supply on a boreal forest floodplain: a mechanism explaining the discrepancy in nitrogen demand and supply

Science.gov (United States)

Lina Koyama; Knut. Kielland

2011-01-01

A discrepancy between plant demand and soil supply of nitrogen (N) has been observed in early successional stages of riparian vegetation in interior Alaska. We hypothesized that a hydrologically mediated N supply serves as a mechanism to balance this apparent deficiency of plant N supply. To test this hypothesis, we conducted a tracer experiment and measured the...

An efficient fluorescent single-particle position tracking system for long-term pulsed measurements of nitrogen-vacancy centers in diamond

Science.gov (United States)

Kim, Kiho; Yun, Jiwon; Lee, Donghyuck; Kim, Dohun

2018-02-01

A simple and convenient design enables real-time three-dimensional position tracking of nitrogen-vacancy (NV) centers in diamond. The system consists entirely of commercially available components (a single-photon counter, a high-speed digital-to-analog converter, a phase-sensitive detector-based feedback device, and a piezo stage), eliminating the need for custom programming or rigorous optimization processes. With a large input range of counters and trackers combined with high sensitivity of single-photon counting, high-speed position tracking (upper bound recovery time of 0.9 s upon 250 nm of step-like positional shift) not only of bright ensembles, but also of low-photon-collection-efficiency single to few NV centers (down to 103 s-1) is possible. The tracking requires position modulation of only 10 nm, which allows simultaneous position tracking and pulsed measurements in the long term. Therefore, this tracking system enables measuring a single-spin magnetic resonance and Rabi oscillations at a very high resolution even without photon collection optimization. The system is widely applicable to various fields related to NV center quantum manipulation research such as NV optical trapping, NV tracking in fluid dynamics, and biological sensing using NV centers inside a biological cell.

Contribution of the isotopic study of nitrogen to the knowledge of the pollution of underground aquifers by nitrates, in agricultural environment (Brie, Beauce - France)

International Nuclear Information System (INIS)

Mariotti, A.; Ben Halima, A.; Berger, G.

1976-01-01

Isotope composition of nitrate nitrogen from aquifers in the highly cultivated areas from Brie and Beauce show three different nitrogen inputs: nitrate from organic matter in soils; nitrate from fertilizers; nitrate from domestic and animal wastes. The isotope composition of those stocks are different enough to trace their origin and establish material balances of nitrogen pollution [fr

Energy assessment of nitrogen variable rate fertilization on wheat; Analise energetica da aplicacao de nitrogenio em taxa variavel em trigo

Energy Technology Data Exchange (ETDEWEB)

Colaco, A.F.; Karam, E.H.; Romanelli, T.L.; Molin, J.P. [Escola Superior de Agricultura Luiz Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Engenharia de Biossistemas], Email: andrecolaco@usp.br; Povh, F.P. [Fundacao ABC Pesquisa e Desenvolvimento Agropecuario, Castro, PR (Brazil)

2011-07-01

Precision Agriculture (PA) is a technique that can reduce the inputs utilization in agriculture production, including the nitrogen fertilizer consume. Great importance is given to this fertilizer, due to its contribution on energy input in agriculture. Methodologies based on the calculation of energy flow of agriculture systems are capable to identify management practices that use energy more efficiently. So, this study's objective is to evaluate the variable-rate nitrogen fertilization on wheat, using energy assessment. This study was carried on in two wheat fields, in which the fertilization was done adopting strips alternated by conventional method (single nitrogen dose) and by nitrogen variable-rate technology. Thus, the input and output energy in the system, energy balance, energy return on investment (EROI) and incorporated energy were determined for each geo-referenced point within the fields. Results showed that less energy was demanded when using variable-rate technology, due to the nitrogen saving, providing greater energy balance, EROI and lower incorporated energy on the areas managed using PA. The energy assessment showed to be an important tool to evaluate systems that use PA, because it is capable of monitoring crops energy potential. (author)

a proposal of nitrogen balance in a very high density olive orchard

African Journals Online (AJOL)

Belguerri H, Villar J.M, Pascual M, Fatmi A, Amadeu A and Rufat J

1 mai 2016 ... balance in both case means that olive tree will provide a peak yield and vegetative growth but ...... Vida rural, 2002, pp. 46-50. ... and Aguilera M.P, Influencia del abonado nitrogenado y potásico en la calidad de aceite de.

Management of regional German river catchments (REGFLUD) impact of nitrogen reduction measures on the nitrogen load in the River Ems and the River Rhine.

Science.gov (United States)

Kunkel, R; Bogena, H; Goemann, H; Kreins, P; Wendland, F

2005-01-01

The REGFLUD-project, commissioned by Germany's Federal Research Ministry (BMBF), addresses the problem of reducing diffuse pollution from agricultural production. The objective of the project is the development and application of multi-criteria scientific methods, which are able to predict diffuse pollution in river basins subject to economic feasibility and social acceptability. The selected river basins (Ems and Rhine basins) cover a variety of landscape units with different hydrological, hydrogeological and socio-economic characteristics. This paper focuses on the analysis of the effects of certain policy measures to reduce diffuse pollution by nitrogen. For this purpose a model system consisting of an agricultural sector model, a water balance model and a residence time/denitrification model was developed and applied. First results indicate a wide range of annual nitrogen surpluses for the rural areas between less than 10 kg N/ha up to 200 kg N/ha or more depending on the type and intensity of farming. Compared to the level of nitrogen surpluses the level of nitrogen inputs into the surface waters is relatively moderate because of degradation processes during transport in soil and groundwater. Policy impact analysis for a nitrogen tax and a limitation of the livestock density stress the importance of regionally tailored measures.

Nitrogen 15 abundance in protein fractions of beans fertilized with ({sup 15}NH{sub 4}){sub 2}SO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Chaud, Saula Goulart; Oliveira, Admar Costa de [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Estudos Agricolas. Dept. de Planejamento Alimentar e Nutricao; Trivelin, Paulo Cesar Ocheuze [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Isotopos Estaveis]. E-mail: admarco@fea.unicamp.br

2002-12-01

Studies evaluating the protein nutritive value of beans labelled with 15 N, using nitrogen balance and the quantitation of faecal and urinary endogenous nitrogen, determined by isotopic dilution, have been extensively used. The objective of this research was to verify if the isotopic labelling of raw, freeze dried beans (Phaseolus vulgaris L., cultivar Pirata 1) with 1.394 atoms % 15 N, resulted in the same abundance of the whole flour and of the protein fractions extracted from the beans with 0.5 mol L{sup -1} NaCl. The isotopic abundance found in the whole bean flour, in the protein extract, in the globulin and albumin fractions were respectively: 1.394 +- 0.011; 1.403 +- 0.012; 1.399 +- 0.007 and 1.399 +- 0.028 atoms % of 15 N, presenting no difference (P > 0.05). However, a difference was found (P < 0.05) between the above mentioned abundances and the isotopic abundance found in the nitrogen of the proteins in the extraction residue, which was 0.969 +- 0.084. Since the abundances did not differ, the protein nutritive indexes, such as digestibility and biological value, determined from the nitrogen balance and corrected for isotopic dilution, would not be affected by extracting the proteins from the beans with 0.5 mol L 1 NaCl. If working with the nitrogen balance of the residual proteins after extraction and even with the whole flours, these indexes could present incorrect values, since the isotopic labelling of the residual proteins was less than that of the protein fractions. (author)

Determination of nitrogen reduction levels necessary to reach groundwater quality targets in Slovenia.

Science.gov (United States)

Andelov, Miso; Kunkel, Ralf; Uhan, Jože; Wendland, Frank

2014-09-01

Within a collaborative project between Slovenian Environment Agency (ARSO) and Research Center Jülich (FZJ), nitrogen reduction levels necessary to reach groundwater quality targets in Slovenia were assessed. For this purpose the hydrological model GROWA-DENUZ was coupled with agricultural N balances and applied consistently to the whole territory of Slovenia in a spatial resolution of 100×100m. GROWA was used to determine the water balance in Slovenia for the hydrologic period 1971-2000. Simultaneously, the displaceable N load in soil was assessed from agricultural Slovenian N surpluses for 2011 and the atmospheric N deposition. Subsequently, the DENUZ model was used to assess the nitrate degradation in soil and, in combination with the percolation water rates from the GROWA model, to determine nitrate concentration in the leachate. The areas showing predicted nitrate concentrations in the leachate above the EU groundwater quality standard of 50mg NO3(-)/L have been identified as priority areas for implementing nitrogen reduction measures. For these "hot spot" areas DENUZ was used in a backward mode to quantify the maximal permissible nitrogen surplus levels in agriculture to guarantee a nitrate concentration in percolation water below 50mg NO3(-)/L. Model results indicate that additional N reduction measures should be implemented in priority areas rather than area-covering. Research work will directly support the implementation of the European Union Water Framework Directive in Slovenia, e.g., by using the maximal permissible nitrogen surplus levels as a framework for the derivation of regionally adapted and hence effective nitrogen reduction measures. Copyright © 2014. Published by Elsevier B.V.

Quantitative determination of heavy nitrogen by spectroscopy

International Nuclear Information System (INIS)

Kumazawa, Kikuo

1974-01-01

Explanation is made on the merits of the determination with heavy nitrogen, the principle and apparatus used for the determination, the method of production of discharge tubes, and the application of the method to several special cases. The spectra belonging to the 2nd positive system are used for the analysis of heavy nitrogen by emission spectroscopy. The spectra near 2980 A are used most often. The bandheads utilizable for the determination are 2976.8 for 14 N 2 , 2982.9 for 14 N 15 N, and 2988.6 A for 15 N 2 , respectively. The sample must be sealed in a discharge tube as nitrogen gas, at first. Mixing of impurities lowers the sensitivity of the determination. The gas pressure is adjusted 10 1-6 Torr. The preparation of gaseous nitrogen is made by either the Rittenberg or the Dumas method. When the amount of a given sample is more than 50 mg, and nitrogen is present as ammonium salt, NH 3 is converted to nitrogen by the reaction with sodium hypobromite. When nitrogen is not present as ammonium salt, Dumas' method is adopted. The amount of heavy nitrogen in the aminoacid separated by thin layer chromatography with silica gel was successfully determined by this method. Simultaneous determination of heavy nitrogen and total nitrogen was also possible by this method. (Fukutomi, T.)

The influence of work-life balance on employees' commitment ...

African Journals Online (AJOL)

The influence of work-life balance on employees' commitment among bankers in Accra, ... balanced their work and family roles better than their married counterparts. ... There was a weak positive relationship between work-life balance and ...

A Comparative Nitrogen Balance and Productivity Analysis of Legume and Non-legume Supported Cropping Systems: The Potential Role of Biological Nitrogen Fixation

DEFF Research Database (Denmark)

Iannetta, Pietro P M; Young, Mark; Bachinger, Johann

2016-01-01

studies have systematically evaluated the effect of optimizing the balance between legumes and non N-fixing crops to optimize production. In addition, the shortage, or even absence in some regions, of measurements of BNF in crops and forages severely limits the ability to design and evaluate new legume......–based agroecosystems. To provide an indication of the magnitude of BNF in European agriculture, a soil-surface N-balance approach was applied to historical data from 8 experimental cropping systems that compared legume and non-legume crop types (e.g., grains, forages and intercrops) across pedoclimatic regions...... the crop sequence, the contribution of BNF to the N-balance increased to reach a maximum when the legume fraction was around 0.5 (legume crops were present in half the years). BNF was lower when the legume fraction increased to 0.6–0.8, not because of any feature of the legume, but because the cropping...

Changes in Olsen Phosphorus Concentration and Its Response to Phosphorus Balance in Black Soils under Different Long-Term Fertilization Patterns

Science.gov (United States)

Zhan, Xiaoying; Zhang, Li; Zhou, Baoku; Zhu, Ping; Zhang, Shuxiang; Xu, Minggang

2015-01-01

The Olsen phosphorus (P) concentration of a soil is a key index that can be used to evaluate the P supply capacity of the soil and to estimate the optimal P fertilization rate. A study of the relationship between the soil Olsen P concentration and the P balance (P input minus P output) and their variations among different fertilization patterns will help to provide useful information for proper management of P fertilization. In this paper, the two investigated long-term experiments were established on black soils in the northeast region of China. Six fertilization treatments were selected: (1) unfertilized (CK); (2) nitrogen only (N); (3) nitrogen and potassium (NK); (4) nitrogen and phosphorus (NP); (5) nitrogen, phosphorus, and potassium (NPK); and (6) nitrogen, phosphorus, potassium and manure (NPKM). The results showed that the average Olsen P concentrations in the black soils at Gongzhuling and Harbin (16- and 31-year study periods, respectively), decreased by 0.49 and 0.56 mg kg-1 a-1, respectively, without P addition and increased by 3.17 and 1.78 mg kg-1 a-1, respectively, with P fertilization. The changes in soil Olsen P concentrations were significantly (P<0.05) correlated with the P balances at both sites except for the NP and NPK treatments at Gongzhuling. Under an average deficit of 100 kg ha-1 P, the soil Olsen P concentration at both sites decreased by 1.36~3.35 mg kg-1 in the treatments without P addition and increased by 4.80~16.04 mg kg-1 in the treatments with 100 kg ha-1 of P accumulation. In addition, the changes in Olsen P concentrations in the soil with 100 kg ha-1of P balance were significantly correlated with the P activation coefficient (PAC, percentage of Olsen P to total P, r=0.99, P<0.01) and soil organic matter content (r=0.91, P<0.01). A low pH was related to large changes of Olsen P by 1 kg ha-1 of P balance. These results indicated that soil organic matter and pH have important effects on the change in soil Olsen P by 1 kg ha-1 of P

Positive muscle protein net balance and differential regulation of atrogene expression after resistance exercise and milk protein supplementation

DEFF Research Database (Denmark)

Reitelseder, Søren; Agergaard, Jakob; Doessing, Simon

2014-01-01

Purpose Resistance exercise and amino acid availability are positive regulators of muscle protein net balance (NB). However, anabolic responses to resistance exercise and protein supplementation deserve further elucidation. The purpose was to compare intakes of whey, caseinate (both: 0.30 g/kg lean...... body mass), or a non-caloric control after heavy resistance exercise on protein turnover and mRNA expressions of forkhead homeobox type O (FOXO) isoforms, muscle RING finger 1 (MuRF1), and Atrogin1 in young healthy males. Methods Protein turnover was determined by stable isotope-labeled leucine...

Balance confidence is related to features of balance and gait in individuals with chronic stroke

Science.gov (United States)

Schinkel-Ivy, Alison; Wong, Jennifer S.; Mansfield, Avril

2016-01-01

Reduced balance confidence is associated with impairments in features of balance and gait in individuals with sub-acute stroke. However, an understanding of these relationships in individuals at the chronic stage of stroke recovery is lacking. This study aimed to quantify relationships between balance confidence and specific features of balance and gait in individuals with chronic stroke. Participants completed a balance confidence questionnaire and clinical balance assessment (quiet standing, walking, and reactive stepping) at 6 months post-discharge from inpatient stroke rehabilitation. Regression analyses were performed using balance confidence as a predictor variable and quiet standing, walking, and reactive stepping outcome measures as the dependent variables. Walking velocity was positively correlated with balance confidence, while medio-lateral centre of pressure excursion (quiet standing) and double support time, step width variability, and step time variability (walking) were negatively correlated with balance confidence. This study provides insight into the relationships between balance confidence and balance and gait measures in individuals with chronic stroke, suggesting that individuals with low balance confidence exhibited impaired control of quiet standing as well as walking characteristics associated with cautious gait strategies. Future work should identify the direction of these relationships to inform community-based stroke rehabilitation programs for individuals with chronic stroke, and determine the potential utility of incorporating interventions to improve balance confidence into these programs. PMID:27955809

Nutritional balance of pigs irradiated on the hind part with 1100 rd of 60Co gamma rays

International Nuclear Information System (INIS)

Daburon, F.; Tricaud, Y.; Bourhoven, D.; Marion, C.

1978-01-01

The hind part of 10 adult miniature pigs was irradiated with 1100 rd of 60 Co gamma rays. The dietary mineral (Na, K, Ca, P), nitrogen and lipid balances of the animals were studied before and 1, 3 and 5 months after irradiation. While the classical early lesion of the intestinal mucosa recovered quite satisfactorily within one or two months, a pancreatic atrophy process developed progressively which might play a major role in the nutritional state of the pigs and thus in their survival. Concerning nutritional balance, nitrogen and sodium retention were perturbed until 5 months post-irradiation; cyanocobalamin absorption remained very low. Dry and organic matter utilization recovered nearly normal values in the 3rd ou 5th month [fr

Arbuscular mycorrhizal (Funneliformis mosseae improves alfalfa (Medicago sativa L. re-growth ability in saline soil through enhanced nitrogen remobilization and improved nutritional balance

Directory of Open Access Journals (Sweden)

Amin Namdari

2018-03-01

Full Text Available In current study, the influence of arbuscular mycorrhizal fungi (AMF on salinity tolerance in terms of root’s reserves remobilization to shoot and its relationship with re-growth ability and ionic status of alfalfa (Medicago sativa L. plants were investigated. In a pot experiment, a factorial experiment in base of randomized complete blocks design in three replications was carried out. Alfalfa plants (Iranian cultivar-Baghdadi inoculated with AMF (Funneliformis mosseae or retained as un-inoculated, were grown in soil and irrigated with three salt concentrations including 1.4 (control, 7 and 12 dS/m. Three harvests were carried out at 10% of flowering stage. AMF inoculation increased the size of root sugars and soluble N pools at harvest time. The shoot biomass production following harvest had a close correlation with nitrogen (N remobilization from root (r=0.92, P≤0.01. However salinity stress significantly reduced amount and percentage of N remobilization to re-growing shoot but AMF plants exhibited greater amount and percentage of root N pools dedicated to remobilization. AMF inoculation also affected ionic relations of plants as AM+ plants contained greater K+ within both root and shoot organs while Ca2+ and Na+ were affected by AMF only within shoot tissue. AMF plants exhibited higher K+/Na+ within shoot and Ca+2/Na+ within root organs. There was a high positive correlation coefficient between K+/Na+, Ca+2/Na+ ratios and N remobilization from root (respectively, r=0.92, 0.88; P≤0.01. To sum up, ionic status within both root and shoot organs, got more balanced by AMF inoculation so that AMF reduced limitations within both source (root and sink (re-growing shoot organs concerning N remobilization to re-growing shoot.

Characterizing bacterial gene expression in nitrogen cycle metabolism with RT-qPCR.

Science.gov (United States)

Graham, James E; Wantland, Nicholas B; Campbell, Mark; Klotz, Martin G

2011-01-01

Recent advances in DNA sequencing have greatly accelerated our ability to obtain the raw information needed to recognize both known and potential novel modular microbial genomic capacity for nitrogen metabolism. With PCR-based approaches to quantifying microbial mRNA expression now mainstream in most laboratories, researchers can now more efficiently propose and test hypotheses on the contributions of individual microbes to the biological accessibility of nitrogen upon which all other life depends. We review known microbial roles in these key nitrogen transformations, and describe the necessary steps in carrying out relevant gene expression studies. An example experimental design is then provided characterizing Nitrosococcus oceani mRNA expression in cultures responding to ammonia. The approach described, that of assessing microbial genome inventory and testing putative modular gene expression by mRNA quantification, is likely to remain an important tool in understanding individual microbial contributions within microbial community activities that maintain the Earth's nitrogen balance. Copyright © 2011 Elsevier Inc. All rights reserved.

Estimated Historical and Current Nitrogen Balances for Illinois

Directory of Open Access Journals (Sweden)

Mark B. David

2001-01-01

Full Text Available The Midwest has large riverine exports of nitrogen (N, with the largest flux per unit area to the Mississippi River system coming from Iowa and Illinois. We used historic and current data to estimate N inputs, outputs, and transformations for Illinois where human activity (principally agriculture and associated landscape drainage have had a dominant impact. Presently, ~800,000 Mg of N is added each year as fertilizer and another 420,000 Mg is biologically fixed, primarily by soybean (Glycine max L. Merr.. These annual inputs are greater than exports in grain, which results in surplus N throughout the landscape. Rivers within the state export approximately 50% of this surplus N, mostly as nitrate, and the remainder appears to be denitrified or temporarily incorporated into the soil organic matter pool. The magnitude of N losses for 1880, 1910, 1950, and 1990 are compared. Initial cultivation of the prairies released large quantities of N (~500,000 Mg N year�1, and resulted in riverine N transport during the late 19th century that appears to have been on the same order of magnitude as contemporary N losses. Riverine flux was estimated to have been at a minimum in about 1950, due to diminished net mineralization and low fertilizer inputs. Residual fertilizer N from corn (Zea mays L., biological N fixed by soybean, short-circuiting of soil water through artificial drainage, and decreased cropping-system diversity appear to be the primary sources for current N export.

Nitrogen transport, transformation, and retention in the Three Gorges Reservoir : A mass balance approach

NARCIS (Netherlands)

Ran, Xiangbin; Bouwman, Lex; Yu, Zhigang; Beusen, Arthur; Chen, Hongtao; Yao, Qingzhen

2017-01-01

Dam construction in river systems affects the biogeochemistry of nitrogen (N), yet most studies on N cycling in reservoirs do not consider the transformations and retention of the different N species. This study addresses the N inputs, transport, transformations, and retention in the Three Gorges

First nitrogen-seeding experiments in JET with the ITER-like Wall

Energy Technology Data Exchange (ETDEWEB)

Oberkofler, M., E-mail: martin.oberkofler@ipp.mpg.de [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Douai, D. [CEA Centre de Cadarache, 13108 Saint Paul lez Durance, Cedex (France); Brezinsek, S.; Coenen, J.W. [Institut für Energie- und Klimaforschung, IEK-4, TEC, Association EURATOM-FZJ, 52425 Jülich (Germany); Dittmar, T. [Center for Energy Research, University of California–San Diego, 9500 Gilman Dr., San Diego, CA 92093-0417 (United States); Drenik, A. [Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Romanelli, S.G. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Joffrin, E. [CEA Centre de Cadarache, 13108 Saint Paul lez Durance, Cedex (France); McCormick, K. [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Brix, M. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Calabro, G. [Associazione EURATOM-ENEA sulla Fusione, Via E. Fermi 45 FRASCATI-Roma (Italy); Clever, M. [Institut für Energie- und Klimaforschung, IEK-4, TEC, Association EURATOM-FZJ, 52425 Jülich (Germany); Giroud, C. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Kruezi, U. [Institut für Energie- und Klimaforschung, IEK-4, TEC, Association EURATOM-FZJ, 52425 Jülich (Germany); Lawson, K. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB (United Kingdom); Linsmeier, Ch. [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); and others

2013-07-15

In this contribution we present results from the first N{sub 2} seeding experiments in JET performed after installation of the ITER-like Wall. Gas balance measurements for seeded L-mode discharges indicate very strong N{sub 2} retention as well as a potential increase in D{sub 2} retention. The possible influence of ammonia production on this apparent retention is discussed. Plasma parameters and impurity content were monitored throughout the seeded discharges as well as during subsequent clean-up discharges. These experiments give first insight into phenomena related to the use of nitrogen as seeding gas in JET with the ITER-like Wall, such as ammonia production and nitrogen legacy.

The impact of diabetes on mobility, balance, and recovery after repositioning maneuvers in individuals with benign paroxysmal positional vertigo.

Science.gov (United States)

D'Silva, Linda J; Whitney, Susan L; Santos, Marcio; Dai, Hongying; Kluding, Patricia M

2017-06-01

The prevalence of benign paroxysmal positional vertigo (BPPV) is higher in people with type 2 diabetes (DM). The impact of DM on mobility, balance, and management of BPPV is unknown. This prospective study compared symptom severity, mobility and balance before and after the canalith repositioning maneuver (CRM) in people with posterior canal BPPV canalithiasis, with and without DM. Fifty participants, BPPV (n=34) and BPPV+DM (n=16) were examined for symptom severity (dizziness handicap inventory, DHI), mobility (functional gait assessment, FGA), and postural sway (using an accelerometer in five conditions) before and after the CRM. The number of maneuvers required for symptom resolution was recorded. At baseline, no differences in DHI or FGA scores were seen between groups, however, people with BPPV+DM had higher sway velocity in the medio-lateral direction in tandem stance (pdiabetes, as well as the influence of diabetic peripheral neuropathy on functional performance are essential. Copyright © 2017 Elsevier Inc. All rights reserved.

Gastrointestinal nitrogen turnover in sheep fed non-protein nitrogen and a phosphorus deficient diet

International Nuclear Information System (INIS)

Breves, G.; Hoeller, H.

1987-01-01

Sheep were fitted with rumen cannulas and re-entrant duodenal and T-shaped ileal cannulas and adapted to a semisynthetic phosphorus deficient diet providing approximately 0.96 g P/d and 14 g N/d, about half of which was in the form of urea-N. Phosphorus repletion was achieved by daily intraduodenal infusion of phosphate, bringing up the daily P supply to about 4.2 g. In P depletion, as well as in P repletion, a series of infusion periods of six days each were established with continuous intraruminal infusion of Cr-ethylenediaminetetra acetic acid as a fluid marker and 15 NH 4 Cl as a marker of microbial N. Gastrointestinal phosphorus and nitrogen balances were established and the net yield of microbial N in the rumen and the flow of microbial N into the duodenum were calculated. The following significant findings were obtained in P depleted sheep. The concentrations of P in plasma and in rumen fluid and the flow of P to the small intestines fell by 60 to 90%; the P balances became negative. The gastrointestinal balance and the flow of N before the large intestines were not affected, but N digestibility in the large intestines was reduced. The daily net yield of microbial N in the rumen was reduced by 27% and the daily flow of microbial N into the duodenum was reduced by 26%. (author)

Nitrogen sparing effect of structured triglycerides containing both medium-and long-chain fatty acids in critically ill patients; a double blind randomized controlled trial.

Science.gov (United States)

Lindgren, B F; Ruokonen, E; Magnusson-Borg, K; Takala, J

2001-02-01

Patients with sepsis and trauma are characterised by hypermetabolism, insulin resistance and protein catabolism. Fat emulsions containing medium chain triglycerides have been suggested to be beneficial for these patients since medium chain fatty acids are a more readily available source of energy when compared to long chain fatty acids. The aim of this study was to compare a medium and long chain triglyceride emulsion consisting of structured triglycerides (ST) with a long chain triglyceride (LCT) emulsion in terms of effects on nitrogen balance, energy metabolism and safety. 30 ICU patients with sepsis or multiple injury received a fat emulsion with ST or 20% LCT (1.5 g triglycerides/kg body weight/day) as a component of total parenteral nutrition (TPN), for 5 days in a double blind randomised parallel group design. The main analysis was made on the 3 day per protocol population due to lack of patients at day 5. There were no differences in baseline characteristics of the two groups receiving either the LCT or the ST emulsion. The efficacy analysis was performed on the per protocol population (n=9 ST, n=11 LCT). There was a significant difference between the two treatments regarding daily nitrogen balances when the first 3 days were analysed P=0.0038). This resulted in an amelioration of the nitrogen balance on day 3 in the group on ST as compared to those on LCT (0.1+/-2.4 g vs -9.9+/-2.1 g P=0.01). The 3 day cumulative nitrogen balance was significantly better in the group receiving ST compared to those on LCT (-0.7+/-6.0 vs -16.7+/-3.9 P=0.03). This better cumulative nitrogen balance on day 3 was also preserved as a tendency (P=0.061) in the analysis of the intention to treat population, but on day 5 there was no significant difference (P=0.08). The ST emulsion was well tolerated and no difference was found compared to the LCT emulsion regarding respiratory quotient, energy expenditure, glucose or triglyceride levels during infusion. Administration of a

Sleep restriction is not associated with a positive energy balance in adolescent boys

DEFF Research Database (Denmark)

Klingenberg, Lars; Chaput, Jean-Philippe; Holmbäck, Ulf

2012-01-01

A short sleep (SS) duration has been linked to obesity in observational studies. However, experimental evidence of the potential mechanisms of sleep restriction on energy balance is conflicting and, to our knowledge, nonexistent in adolescents.......A short sleep (SS) duration has been linked to obesity in observational studies. However, experimental evidence of the potential mechanisms of sleep restriction on energy balance is conflicting and, to our knowledge, nonexistent in adolescents....

Extended state observer–based fractional order proportional–integral–derivative controller for a novel electro-hydraulic servo system with iso-actuation balancing and positioning

Directory of Open Access Journals (Sweden)

Qiang Gao

2015-12-01

Full Text Available Aiming at balancing and positioning of a new electro-hydraulic servo system with iso-actuation configuration, an extended state observer–based fractional order proportional–integral–derivative controller is proposed in this study. To meet the lightweight requirements of heavy barrel weapons with large diameters, an electro-hydraulic servo system with a three-chamber hydraulic cylinder is especially designed. In the electro-hydraulic servo system, the balance chamber of the hydraulic cylinder is used to realize active balancing of the unbalanced forces, while the driving chambers consisting of the upper and lower chambers are adopted for barrel positioning and dynamic compensation of external disturbances. Compared with conventional proportional–integral–derivative controllers, the fractional order proportional–integral–derivative possesses another two adjustable parameters by expanding integer order to arbitrary order calculus, resulting in more flexibility and stronger robustness of the control system. To better compensate for strong external disturbances and system nonlinearities, the extended state observer strategy is further introduced to the fractional order proportional–integral–derivative control system. Numerical simulation and bench test indicate that the extended state observer–based fractional order proportional–integral–derivative significantly outperforms proportional–integral–derivative and fractional order proportional–integral–derivative control systems with better control accuracy and higher system robustness, well demonstrating the feasibility and effectiveness of the proposed extended state observer–based fractional order proportional–integral–derivative control strategy.

Accounting for the biogeochemical cycle of nitrogen in input-output life cycle assessment.

Science.gov (United States)

Singh, Shweta; Bakshi, Bhavik R

2013-08-20

Nitrogen is indispensable for sustaining human activities through its role in the production of food, animal feed, and synthetic chemicals. This has encouraged significant anthropogenic mobilization of reactive nitrogen and its emissions into the environment resulting in severe disruption of the nitrogen cycle. This paper incorporates the biogeochemical cycle of nitrogen into the 2002 input-output model of the U.S. economy. Due to the complexity of this cycle, this work proposes a unique classification of nitrogen flows to facilitate understanding of the interaction between economic activities and various flows in the nitrogen cycle. The classification scheme distinguishes between the mobilization of inert nitrogen into its reactive form, use of nitrogen in various products, and nitrogen losses to the environment. The resulting inventory and model of the US economy can help quantify the direct and indirect impacts or dependence of economic sectors on the nitrogen cycle. This paper emphasizes the need for methods to manage the N cycle that focus not just on N losses, which has been the norm until now, but also include other N flows for a more comprehensive view and balanced decisions. Insight into the N profile of various sectors of the 2002 U.S. economy is presented, and the inventory can also be used for LCA or Hybrid LCA of various products. The resulting model is incorporated in the approach of Ecologically-Based LCA and available online.

Including spatial data in nutrient balance modelling on dairy farms

Science.gov (United States)

van Leeuwen, Maricke; van Middelaar, Corina; Stoof, Cathelijne; Oenema, Jouke; Stoorvogel, Jetse; de Boer, Imke

2017-04-01

The Annual Nutrient Cycle Assessment (ANCA) calculates the nitrogen (N) and phosphorus (P) balance at a dairy farm, while taking into account the subsequent nutrient cycles of the herd, manure, soil and crop components. Since January 2016, Dutch dairy farmers are required to use ANCA in order to increase understanding of nutrient flows and to minimize nutrient losses to the environment. A nutrient balance calculates the difference between nutrient inputs and outputs. Nutrients enter the farm via purchased feed, fertilizers, deposition and fixation by legumes (nitrogen), and leave the farm via milk, livestock, manure, and roughages. A positive balance indicates to which extent N and/or P are lost to the environment via gaseous emissions (N), leaching, run-off and accumulation in soil. A negative balance indicates that N and/or P are depleted from soil. ANCA was designed to calculate average nutrient flows on farm level (for the herd, manure, soil and crop components). ANCA was not designed to perform calculations of nutrient flows at the field level, as it uses averaged nutrient inputs and outputs across all fields, and it does not include field specific soil characteristics. Land management decisions, however, such as the level of N and P application, are typically taken at the field level given the specific crop and soil characteristics. Therefore the information that ANCA provides is likely not sufficient to support farmers' decisions on land management to minimize nutrient losses to the environment. This is particularly a problem when land management and soils vary between fields. For an accurate estimate of nutrient flows in a given farming system that can be used to optimize land management, the spatial scale of nutrient inputs and outputs (and thus the effect of land management and soil variation) could be essential. Our aim was to determine the effect of the spatial scale of nutrient inputs and outputs on modelled nutrient flows and nutrient use efficiencies

Substitutional Nitrogen in Nanodiamond and Bucky-Diamond Particles

Energy Technology Data Exchange (ETDEWEB)

Barnard, Amanda S.; Sternberg, Michael G.

2005-09-15

The inclusion of dopants (such as nitrogen) in diamond nanoparticles is expected to be important for use in future nanodevices, such as qubits for quantum computing. Although most commercial diamond nanoparticles contain a small fraction of nitrogen, it is still unclear whether it is located within the core or at the surface of the nanoparticle. Presented here are density functional tight binding simulations examining the configuration, potential energy surface, and electronic charge of substitutional nitrogen in nanodiamond and bucky-diamond particles. The results predict that nitrogen is likely to be positioned at the surface of both hydrogenated nanodiamond and (dehydrogenated) bucky-diamond, and that the coordination of the dopants within the particles is dependent upon the surface structure.

Dynamic Analysis of a Pendulum Dynamic Automatic Balancer

Directory of Open Access Journals (Sweden)

Jin-Seung Sohn

2007-01-01

Full Text Available The automatic dynamic balancer is a device to reduce the vibration from unbalanced mass of rotors. Instead of considering prevailing ball automatic dynamic balancer, pendulum automatic dynamic balancer is analyzed. For the analysis of dynamic stability and behavior, the nonlinear equations of motion for a system are derived with respect to polar coordinates by the Lagrange's equations. The perturbation method is applied to investigate the dynamic behavior of the system around the equilibrium position. Based on the linearized equations, the dynamic stability of the system around the equilibrium positions is investigated by the eigenvalue analysis.

Preferential flow, nitrogen transformations and 15N balance under urine-affected areas of irrigated and non-irrigated clover-based pastures

Science.gov (United States)

Pakro, Naser; Dillon, Peter

1995-12-01

Urine-affected areas can lead to considerable losses of N by leaching, ammonia volatilisation and denitrification from dairy pastures in the southeast of South Australia. Potable groundwater supplies are considered to have become contaminated by nitrate as a result of leaching from these leguminous pastures. Dairy cow urine, labelled with 15N urea, was applied to micro-plots and mini-lysimeters installed in two adjacent irrigated (white clover-rye grass) and non-irrigated (subterranean clover-annual grasses) paddocks of a dairy farm on four occasions representing different seasonal conditions. These experiments allowed measurement of nitrogen transformations, recovery of 15N in the pasture and soil, and leaching below various depths. Gaseous losses were calculated from the nitrogen balance. The results of the four experiments showed that within a day of urine application up to 40% of the applied urinary-N was leached below a depth of 150 mm as a result of macropore flow in the irrigated paddock, and up to 24% in the non-irrigated one. After application to the irrigated paddock 17% of the urinary-N moved immediately below 300 mm but only 2% below the 450-mm depth. The urinary-N remaining in the soil was converted from urea to ammonium within a day regardless of season. Within the first 7 days of application six times more nitrate was produced in summer than in winter. This has obvious implications for leaching potential. Leaching of 15N from the top 150 mm of soil, following urine applications in all seasons, was between 41% and 62% of the applied 15N in the irrigated paddock and 25-51% in the non-irrigated paddock. However, leaching losses measured at depths of 300 or 450 mm were smaller by a factor of 2-4. The leaching loss of 15N applied in spring in both paddocks was 41% below 150 mm and 12% below 450 mm. Recovery of 15N from the soil-plant system in the 450-nm deep lysimeters was ˜60% of that applied. Estimated ammonia was ˜9% of applied 15N with no paddock

Do Family Responsibilities and a Clinical Versus Research Faculty Position Affect Satisfaction with Career and Work–Life Balance for Medical School Faculty?

Science.gov (United States)

Beckett, Laurel; Nettiksimmons, Jasmine; Howell, Lydia Pleotis

2015-01-01

Abstract Background: Balancing career and family obligations poses challenges to medical school faculty and contributes to dissatisfaction and attrition from academics. We examined the relationship between family setting and responsibilities, rank, and career and work–life satisfaction for faculty in a large U.S. medical school. Methods: Baseline faculty surveys were analyzed from the first year of a 4-year National Institutes of Health–funded study to evaluate awareness, knowledge, attitudes, and use of family friendly policies and career satisfaction. The study focus was on the impact of family responsibilities and characteristics of the faculty position (rank, clinical vs. nonclinical, and academic series) in multivariate comparisons between primary predictors and outcomes of interest. Results: Both clinical and family responsibilities for children under 18 play a major and interacting role in satisfaction with career and work–life balance. Clinical faculty respondents without children at home reported significantly greater career satisfaction and better work–life balance than their nonclinical counterparts. Nonclinical faculty respondents with children reported greater satisfaction and better balance than counterparts without family responsibilities. However, the advantage in career satisfaction and work–life balance for clinical faculty respondents disappeared for those with responsibility for young children. No gender-based differences were noted in the results or across faculty rank for respondents; however, for women, reaching associate professor resulted in greater career satisfaction. Conclusion: This study suggests that both work-related factors and family responsibilities influence satisfaction with career and work–life balance, but the predictors appear to interact in complex and nuanced ways. Further research is needed to delineate more clearly these interactions and to explore other factors that may play important additional roles. PMID

Do Family Responsibilities and a Clinical Versus Research Faculty Position Affect Satisfaction with Career and Work-Life Balance for Medical School Faculty?

Science.gov (United States)

Beckett, Laurel; Nettiksimmons, Jasmine; Howell, Lydia Pleotis; Villablanca, Amparo C

2015-06-01

Balancing career and family obligations poses challenges to medical school faculty and contributes to dissatisfaction and attrition from academics. We examined the relationship between family setting and responsibilities, rank, and career and work-life satisfaction for faculty in a large U.S. medical school. Baseline faculty surveys were analyzed from the first year of a 4-year National Institutes of Health-funded study to evaluate awareness, knowledge, attitudes, and use of family friendly policies and career satisfaction. The study focus was on the impact of family responsibilities and characteristics of the faculty position (rank, clinical vs. nonclinical, and academic series) in multivariate comparisons between primary predictors and outcomes of interest. Both clinical and family responsibilities for children under 18 play a major and interacting role in satisfaction with career and work-life balance. Clinical faculty respondents without children at home reported significantly greater career satisfaction and better work-life balance than their nonclinical counterparts. Nonclinical faculty respondents with children reported greater satisfaction and better balance than counterparts without family responsibilities. However, the advantage in career satisfaction and work-life balance for clinical faculty respondents disappeared for those with responsibility for young children. No gender-based differences were noted in the results or across faculty rank for respondents; however, for women, reaching associate professor resulted in greater career satisfaction. This study suggests that both work-related factors and family responsibilities influence satisfaction with career and work-life balance, but the predictors appear to interact in complex and nuanced ways. Further research is needed to delineate more clearly these interactions and to explore other factors that may play important additional roles.

Work-life balance of nursing faculty in research- and practice-focused doctoral programs.

Science.gov (United States)

Smeltzer, Suzanne C; Sharts-Hopko, Nancy C; Cantrell, Mary Ann; Heverly, Mary Ann; Jenkinson, Amanda; Nthenge, Serah

2015-01-01

The growing shortage of nursing faculty and the need for faculty to teach doctoral students to address the shortage call for examination of factors that may contribute to the shortage, including those that are potentially modifiable, including work-life balance.This descriptive study examined work-life balance of a national sample of nursing faculty teaching in research-focused and practice-focused doctoral programs. Data were collected through an online survey of 554 doctoral program faculty members to identify their perceptions of work-life balance and predictors of work-life balance. Work-life balance scores indicated better work-life balance than expected. Factors associated with good work-life balance included higher academic rank, having tenure, older age, years in education, current faculty position, and no involvement in clinical practice. Current faculty position was the best predictor of work-life balance. Although work-life balance was viewed positively by study participants, efforts are needed to strengthen factors related to positive work/life in view of the increasing workload of doctoral faculty as the numbers of doctoral students increase and the number of seasoned faculty decrease with anticipated waves of retirements. Copyright © 2015 Elsevier Inc. All rights reserved.

Studies with nitrogen-15-labelled amino acids for a quantitative description of nitrogen metabolism in man

International Nuclear Information System (INIS)

Hartig, W.; Faust, H.; Czarnetzki, H.D.; Winkler, E.; Akademie der Wissenschaften der DDR, Leipzig. Zentralinstitut fuer Isotopen- und Strahlenforschung)

1977-01-01

The utilization of glycine in healthy and stressed persons has been studied by continuous infusion or oral administration. The results of our studies show that (1) Breakdown of protein is increased in stress conditions; (2) Amino acids are also synthesized to protein in stress, the percentage of amino acids used for synthesis being smaller in stress conditions; (3) The urea synthesis during stress is increased and accelerated; (4) In the isotopic steady state 23% of the 15 N-glycine administered by infusion to healthy persons and 41% of the amount administered to patients after cholecystectomy is eliminated (urea 16%/26%; ammonia 4%/5%); using a single oral dose 24% is eliminated as total N after 24h (19% as 15 N-urea and 4% as 15 N-ammonia); (5) Depending on the method of gastric surgery the absorption and elimination rate of glycine-N varied; the more rapid intestinal absorption of glycine in comparison with healthy persons leads to a higher 15 N elimination via urine, and causes a disturbance of the nitrogen metabolism and nitrogen balance. (author)

Effect of feeding a by-product feed-based silage on nutrients intake, apparent digestibility, and nitrogen balance in sheep.

Science.gov (United States)

Seok, J S; Kim, Y I; Lee, Y H; Choi, D Y; Kwak, W S

2016-01-01

Literature is lacking on the effects of feeding by-product feed (BF)-based silage on rumen fermentation parameters, nutrient digestion and nitrogen (N) retention in sheep. Therefore, this study was conducted to determine the effect of replacing rye straw with BF-based silage as a roughage source on ruminal parameters, total-tract apparent nutrient digestibility, and N balance in sheep. The by-product feed silage was composed of spent mushroom substrate (SMS) (45 %), recycled poultry bedding (RPB) (21 %), rye straw (11 %), rice bran (10.8 %), corn taffy residue (10 %), protected fat (1.0 %), bentonite (0.6 %), and mixed microbial additive (0.6 %). Six sheep were assigned randomly to either the control (concentrate mix + rye straw) or a treatment diet (concentrate mix + BF-based silage). Compared with the control diet, feeding a BF-based silage diet resulted in similar ruminal characteristics (pH, acetate, propionate, and butyrate concentrations, and acetate: propionate ratio), higher (p < 0.05) ruminal NH3-N, higher (p < 0.05) ether extract digestibility, similar crude protein digestibility, lower (p < 0.05) dry matter, fiber, and crude ash digestibilities, and higher (p < 0.05) N retention (g/d). The BF-based silage showed similar energy value, higher protein metabolism and utilization, and lower fiber digestion in sheep compared to the control diet containing rye straw.

Positive long-term effects of Pilates exercise on the aged-related decline in balance and strength in older, community-dwelling men and women.

Science.gov (United States)

Bird, Marie-Louise; Fell, James

2014-07-01

This study investigated the effect of Pilates exercise on physical fall risk factors 12 months after an initial 5-week Pilates intervention. The authors hypothesized that ongoing Pilates participation would have a positive effect on physical fall risk factors in those who continued with Pilates exercise compared with those who ceased. Thirty older ambulatory adults (M = 69 years, SD = 7) participated in Pilates classes for 5 weeks with testing preintevention (Time 1 [T1]) and postintervention (Time 2 [T2]) and 12 months later (Time 3 [T3]). Balance and leg strength were compared using a 2-way analysis of variance with repeated measures. Postural sway, dynamic balance, and function improvements evident after the initial Pilates training (T1-T2) were maintained at T3 (p Pilates (n = 14) and those who had ceased. Balance improvements after a short Pilates intervention were maintained 1 year later in all participants, with increased benefits from ongoing participation.

In vivo quantification of body nitrogen for nutritional assessment

International Nuclear Information System (INIS)

Cohn, S.H.; Vaswani, A.N.; Vartsky, D.; Yasumura, S.; Sawitsky, A.; Gartenhaus, W.; Ellis, K.J.

1982-01-01

A series of experimental tests were carried out to study total body nitrogen (TBN), total body potassium (TBK), total body water (TBW) and total body calcium (TBCa). The prompt neutron activation and whole body counting techniques were used to measure TBN and TBK, respectively. TBW was measured with the use of the standard tritiated water radioisotopic technique. Three groups of subjects were studied: normal controls, obese women on protein sparing diets, and cancer patients on chemotherapy. In relation to TBN, the obese patients showed a minimal negative nitrogen balance 0.49 to 0.87 g/day. With regard to the cancer patients, the data obtained in this study clearly corroborate the clinical observations. In patients with severe wasting, it is the skeletal muscle mass that is predominantly lost, not the visceral life-supporting system

Defect-induced Catalysis toward the Oxygen Reduction Reaction in Single-walled Carbon Nanotube: Nitrogen doped and Non-nitrogen doped

International Nuclear Information System (INIS)

Lu, Di; Wu, Dan; Jin, Jian; Chen, Liwei

2016-01-01

Single-walled carbon nanotubes (SWNTs) are post-treated by argon (Ar) or ammonia (NH 3 ) plasma irradiation to introduce defects that are potentially related to catalysis towards the oxygen reduction reaction (ORR). Electrochemical characterization in alkali medium suggests that the plasma irradiated SWNTs demonstrate enhanced catalytic activity toward the ORR with a positively shifted threshold potential. Moreover the enhanced desired four-electron pathway catalytic activity, which exhibited as the positive shifted threshold potential, is independent of the nitrogen dopant. The nature of the defects is probed with Raman and X-ray photoelectron spectroscopy. The results indicate that the non-nitrogen doped defects of SWNTs contribute to the actual active site for the ORR.

Patella position is not a determinant for anterior knee pain 10 years after balanced gap total knee arthroplasty.

Science.gov (United States)

van Houten, Albert H; Heesterbeek, Petra J C; Wymenga, Ate B

2016-08-01

Incidence of anterior knee pain after total knee arthroplasty (TKA) is reported to be between 4 and 49 %. The incidence of AKP at long-term follow-up and possible determinants after cruciate cruciate-retaining TKA were investigated. A 10-year follow-up of a cohort of 55 patients (63 TKAs), who received the balanSys™ cruciate-retaining total knee system (Mathys Ltd, Bettlach, Switzerland) between 1999 and 2002, was performed. Patients had undergone the balanced gap technique, with either a fixed bearing or an AP-glide bearing. Standardised diagnostic questions regarding AKP were collected and categorised into two groups: those with and without AKP. The lateral patellar tilt, patellar displacement measurement and modified Insall-Salvati ratio were used for patella position evaluation on skyline radiographs. The Knee Society Score (KSS), the Knee Osteoarthritis Outcome Score (KOOS) and Numerical Rating Scales (NRS) for pain and satisfaction were obtained at follow-up. Sixteen patients in the study population experienced AKP. Incidence of AKP (fixed bearing 13/44; AP-glide bearing baring 3/17) was not dependent on type of insert (n.s.). There were no statistical differences in patella position and tibiofemoral contact point between the AKP group and the no AKP group (n.s.). KSS, KOOS, NRS-pain and NRS-satisfaction were significantly lower for the patients with AKP (all p years after balanced gap TKA. Postoperative patella positioning was not found to be a determinant for anterior knee pain after TKA. However, patellar displacement does not seem completely favourable. Moreover, type of bearing was not found a determinant for AKP at long-term follow-up. Lower quality prospective cohort study (<80 % follow-up, patients enrolled at different time points in disease), Level II.

21 CFR 862.1515 - Nitrogen (amino-nitrogen) test system.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nitrogen (amino-nitrogen) test system. 862.1515... Systems § 862.1515 Nitrogen (amino-nitrogen) test system. (a) Identification. A nitrogen (amino-nitrogen) test system is a device intended to measure amino acid nitrogen levels in serum, plasma, and urine...

Optimal leaf positions for chlorophyll meter measurement in rice

Directory of Open Access Journals (Sweden)

Zhaofeng eYuan

2016-05-01

Full Text Available The Soil Plant Analysis Development (SPAD chlorophyll meter is one of the most commonly used diagnostic tools to measure crop nitrogen status. However, the measurement method of the meter could significantly affect the accuracy of the final estimation. Thus, this research was undertaken to develop a new methodology to optimize SPAD meter measurements in rice (Oryza sativa L.. A flatbed color scanner was used to map the dynamic chlorophyll distribution and irregular leaf shapes. Calculus algorithm was adopted to estimate the potential positions for SPAD meter measurement along the leaf blade. Data generated by the flatbed color scanner and SPAD meter were analysed simultaneously. The results suggested that a position 2/3 of the distance from the leaf base to the apex (2/3 position could represent the chlorophyll content of the entire leaf blade, as indicated by the relatively low variance of measurements at that positon. SPAD values based on di-positional leaves and the extracted chlorophyll a and b contents were compared. This comparison showed that the 2/3 position on the lower leaves tended to be more sensitive to changes in chlorophyll content. Finally, the 2/3 position and average SPAD values of the fourth fully expanded leaf from the top were compared with leaf nitrogen concentration. The results showed the 2/3 position on that leaf was most suitable for predicting the nitrogen status of rice. Based on these results, we recommend making SPAD measurements at the 2/3 position on the fourth fully expanded leaf from the top. The coupling of dynamic chlorophyll distribution and irregular leaf shapes information can provide a promising approach for the calibration of SPAD meter measurement, which can further benefit the in situ nitrogen management by providing reliable estimation of crops nitrogen nutrition status.

Uptake of fertilizer nitrogen and soil nitrogen by rice using 15N-labelled nitrogen fertilizer

International Nuclear Information System (INIS)

Reddy, K.R.; Patrick, W.H. Jr.

1980-01-01

Data from five field experiments using labelled nitrogen fertilizer were used to determine the relative effects of soil nitrogen and fertilizer nitrogen on rice yield. Yield of grain was closely correlated with total aboveground nitrogen uptake (soil + fertilizer), less closely correlated with soil nitrogen uptake and not significantly correlated with fertilizer nitrogen uptake. When yield increase rather than yield was correlated with fertilizer nitrogen uptake, the correlation coefficient was statistically significant. (orig.)

Marketing research in positioning and launching of yoghurt with a balanced chemical composition

Directory of Open Access Journals (Sweden)

M. Mardar

2016-12-01

Full Text Available Annotation. This article presents the analysis of marketing environment of the enterprises that produce yogurt products in Ukraine. In order to carry out a deeper analysis of the marketing environment of the new yoghurt drinks with a balanced composition of the major nutrients in food and increased probiotic properties, PEST and SWOT-analyses were conducted, they identified environmental factors that have favorable and adverse effects as well as internal strengths and weaknesses of the new product. Based on the results of marketing research of consumer preferences, the core audience of new yoghurt drink with a balanced chemical composition and the elevated concentration of Bifidobacteria were defined. The received results led to justification of the expediency of elaboration of new yoghurt drinks with probiotic properties and balanced composition of basic food nutrients as well as to formulation of a strategy of new product promotion on the consumer market of Ukraine.

The importance of dissimilatory nitrate reduction to ammonium (DNRA) in the nitrogen cycle of coastal ecosystems

DEFF Research Database (Denmark)

Giblin, Anne E.; Tobias, Craig R.; Song, Bongkeun

2013-01-01

Until recently, it was believed that biological assimilation and gaseous nitrogen (N) loss through denitrification were the two major fates of nitrate entering or produced within most coastal ecosystems. Denitrification is often viewed as an important ecosystem service that removes reactive N from...... the ecosystem. However, there is a competing nitrate reduction process, dissimilatory nitrate reduction to ammonium (DNRA), that conserves N within the ecosystem. The recent application of nitrogen stable isotopes as tracers has generated growing evidence that DNRA is a major nitrogen pathway that cannot...... of denitrification and DNRA, and how the balance changes with increased nitrogen loading, is of critical importance for predicting eutrophication trajectories. Recent improvements in methods for assessing rates of DNRA have helped refine our understanding of the rates and controls of this process, but accurate...

Balance across contexts: importance of balanced need satisfaction across various life domains.

Science.gov (United States)

Milyavskaya, Marina; Gingras, Isabelle; Mageau, Geneviève A; Koestner, Richard; Gagnon, Hugo; Fang, Jianqun; Boiché, Julie

2009-08-01

Self-determination theory posits that satisfaction of three basic psychological needs-autonomy, competence, and relatedness-are required for psychological well-being, and a recent study showed that the balance in the satisfaction of these three needs independently affects well-being. The present investigation builds on these findings by examining the balance of adolescents' need satisfaction across distinct life contexts. The results of three studies show that adolescents who experience a balance of need satisfaction across important life contexts, including at school, at home, with friends, and in part-time jobs, reported higher well-being and better school adjustment. This finding emerged consistently across four countries and across multiple measures of school adjustment, including teacher reports. Together, these results support previous research that highlights the importance of consistency for psychological functioning.

Effects of top-dressing recycled broiler litter on litter production, litter characteristics, and nitrogen mass balance.

Science.gov (United States)

Coufal, C D; Chavez, C; Niemeyer, P R; Carey, J B

2006-03-01

Top-dressing is a method of broiler litter management in which a thin layer of new, clean litter material is spread over the top of previously used litter prior to placement of a new flock. This fresh layer of bedding material increases the absorptive capacity of the litter and decreases litter caking. Although this practice has been widely used in the poultry industry for many years, no research has been conducted to quantify the effects the practice has on broiler performance, litter production rates, and nutrient content, or the ability of broiler litter to retain manure N and prevent volatilization. An experiment was conducted to quantify these parameters under simulated commercial conditions in a research facility. Nine consecutive flocks of broilers were reared on recycled broiler litter that had previously been used for 9 flocks. Control pens received no litter treatment whereas top-dressed pens received a thin layer of new rice hulls (1 to 2 cm) before the placement of each flock. Nitrogen loss was calculated using the mass balance method. Average broiler performance was not different between the top-dressed and control pens. Top-dressing of litter significantly (P dressed pens compared with control pens. As a result, litter C:N ratios were significantly higher for pens with top-dressed litter. Differences in N loss between the treatments were not consistent. Average N loss for all flocks was 10.61 and 11.92 g of N/kg of marketed broiler for control and top-dressed pens, respectively, or 20.1 and 22.5% of N inputs, respectively. Based on this experiment, top-dressing of recycled broiler litter would not be recommended as a strategy to reduce the volatilization of N from broiler rearing facilities and, in fact, may actually increase N loss.

Cosmological evolution of the nitrogen abundance

Science.gov (United States)

Vangioni, Elisabeth; Dvorkin, Irina; Olive, Keith A.; Dubois, Yohan; Molaro, Paolo; Petitjean, Patrick; Silk, Joe; Kimm, Taysun

2018-06-01

The abundance of nitrogen in the interstellar medium is a powerful probe of star formation processes over cosmological time-scales. Since nitrogen can be produced both in massive and intermediate-mass stars with metallicity-dependent yields, its evolution is challenging to model, as evidenced by the differences between theoretical predictions and observations. In this work, we attempt to identify the sources of these discrepancies using a cosmic evolution model. To further complicate matters, there is considerable dispersion in the abundances from observations of damped Lyα absorbers (DLAs) at z ˜ 2-3. We study the evolution of nitrogen with a detailed cosmic chemical evolution model and find good agreement with these observations, including the relative abundances of (N/O) and (N/Si). We find that the principal contribution of nitrogen comes from intermediate-mass stars, with the exception of systems with the lowest N/H, where nitrogen production might possibly be dominated by massive stars. This last result could be strengthened if stellar rotation which is important at low metallicity can produce significant amounts of nitrogen. Moreover, these systems likely reside in host galaxies with stellar masses below 108.5 M⊙. We also study the origin of the observed dispersion in nitrogen abundances using the cosmological hydrodynamical simulations Horizon-AGN. We conclude that this dispersion can originate from two effects: difference in the masses of the DLA host galaxies, and difference in their position inside the galaxy.

PipY, a Member of the Conserved COG0325 Family of PLP-Binding Proteins, Expands the Cyanobacterial Nitrogen Regulatory Network

Directory of Open Access Journals (Sweden)

José I. Labella

2017-07-01

Full Text Available Synechococcus elongatus PCC 7942 is a paradigmatic model organism for nitrogen regulation in cyanobacteria. Expression of genes involved in nitrogen assimilation is positively regulated by the 2-oxoglutarate receptor and global transcriptional regulator NtcA. Maximal activation requires the subsequent binding of the co-activator PipX. PII, a protein found in all three domains of life as an integrator of signals of the nitrogen and carbon balance, binds to PipX to counteract NtcA activity at low 2-oxoglutarate levels. PII-PipX complexes can also bind to the transcriptional regulator PlmA, whose regulon remains unknown. Here we expand the nitrogen regulatory network to PipY, encoded by the bicistronic operon pipXY in S. elongatus. Work with PipY, the cyanobacterial member of the widespread family of COG0325 proteins, confirms the conserved roles in vitamin B6 and amino/keto acid homeostasis and reveals new PLP-related phenotypes, including sensitivity to antibiotics targeting essential PLP-holoenzymes or synthetic lethality with cysK. In addition, the related phenotypes of pipY and pipX mutants are consistent with genetic interactions in the contexts of survival to PLP-targeting antibiotics and transcriptional regulation. We also showed that PipY overexpression increased the length of S. elongatus cells. Taken together, our results support a universal regulatory role for COG0325 proteins, paving the way to a better understanding of these proteins and of their connections with other biological processes.

Validity and reliability of wii fit balance board for the assessment of balance of healthy young adults and the elderly.

Science.gov (United States)

Chang, Wen-Dien; Chang, Wan-Yi; Lee, Chia-Lun; Feng, Chi-Yen

2013-10-01

[Purpose] Balance is an integral part of human ability. The smart balance master system (SBM) is a balance test instrument with good reliability and validity, but it is expensive. Therefore, we modified a Wii Fit balance board, which is a convenient balance assessment tool, and analyzed its reliability and validity. [Subjects and Methods] We recruited 20 healthy young adults and 20 elderly people, and administered 3 balance tests. The correlation coefficient and intraclass correlation of both instruments were analyzed. [Results] There were no statistically significant differences in the 3 tests between the Wii Fit balance board and the SBM. The Wii Fit balance board had a good intraclass correlation (0.86-0.99) for the elderly people and positive correlations (r = 0.58-0.86) with the SBM. [Conclusions] The Wii Fit balance board is a balance assessment tool with good reliability and high validity for elderly people, and we recommend it as an alternative tool for assessing balance ability.

Recent Nitrogen Deposition In Poland Monitored With The Moss Pleurozium Schreberi

Directory of Open Access Journals (Sweden)

Kapusta Paweł

2014-07-01

Full Text Available In this study, atmospheric deposition of nitrogen was determined for Poland by moss biomonitoring. Nitrogen content was measured in the moss Pleurozium schreberi (Willd. ex Brid. Mitt. sampled in 2010 from 320 sites evenly distributed throughout the country. Mosses (green parts contained an average 1.56% nitrogen. The result places Poland among the European countries most polluted by airborne nitrogen. The highest nitrogen concentrations were found in mosses from the central and southern parts of the country, and the lowest in samples from some eastern and northern regions. Multiple regression showed that this variability was due mostly to nitrogen emissions from agricultural and industrial areas (moss nitrogen was positively associated with the consumption of mineral nitrogen fertilizers and the magnitude of particulate pollution. Some details of the spatial variability of the nitrogen data indicate that local and regional point sources of pollution (e.g., chemical plants played an important role in shaping the nitrogen deposition pattern

Forests, nitrogen and albedo, a very interesting trio indeed

Directory of Open Access Journals (Sweden)

Borghetti M

2009-01-01

Full Text Available A short comment is made on a recent paper (Ollinger et al. 2008 which shows that forest ecosystem carbon uptake in temperate and boreal forests is directly related to canopy nitrogen concentration and that both carbon uptake capacity and canopy nitrogen concentration are positively correlated with shortwave surface albedo measured with broad-band satellite sensors.

Effect of delayed wrapping and wrapping source on nitrogen balance and blood urea nitrogen in gestating sheep offered alfalfa silage

Science.gov (United States)

Exposing ensiled forage to oxygen can result in DM deterioration and reduce silage intake by animals. This study was conducted to investigate the effects of 2 different wrapping sources and time intervals between baling and wrapping on N balance and blood urea N in gestating sheep offered alfalfa si...

Prognostic implications of fluid balance in ST elevation myocardial infarction complicated by cardiogenic shock.

Science.gov (United States)

Arbel, Yaron; Mass, Ronen; Ziv-Baran, Tomer; Khoury, Shafik; Margolis, Gilad; Sadeh, Ben; Flint, Nir; Ben-Shoshan, Jeremy; Finn, Talya; Keren, Gad; Shacham, Yacov

2017-08-01

Positive fluid balance has been associated with adverse outcomes in patients admitted to general intensive care units. We analysed the relationship between a positive fluid balance and its persistence over time in terms of in-hospital outcomes among ST elevation myocardial infarction (STEMI) patients complicated by cardiogenic shock. We retrospectively studied fluid intake and output for 96 hours following hospital admission in 48 consecutive adult patients with STEMI complicated by cardiogenic shock, all undergoing primary angioplasty. Daily and accumulated fluid balance was registered at up to 96 hours following admission. The cohort was stratified into two groups based on the presence or absence of positive fluid balance on day 4. Patients' records were assessed for in-hospital adverse outcomes, as well as 30-day all-cause mortality. A positive fluid balance was present in 19/48 patients (40%). Patients with positive fluid balance were older and more likely to be treated by intra-aortic balloon counter-pulsation and antibiotics. These patients were more likely to develop acute kidney injury and to need new intubation and were less likely to have renal function recovery as well as successful weaning from mechanical ventilation ( p balance had higher 30-day mortality (68% vs. 10%; p balance, the adjusted risk for 30-day mortality increased by 24% (hazard ratio: 1.24, 95% confidence interval: 1.07-1.42; p = 0.003). A positive fluid balance was strongly associated with higher 30-day mortality in STEMI complicated by cardiogenic shock.

Carbon and nitrogen stoichiometry across stream ecosystems

Science.gov (United States)

Wymore, A.; Kaushal, S.; McDowell, W. H.; Kortelainen, P.; Bernhardt, E. S.; Johnes, P.; Dodds, W. K.; Johnson, S.; Brookshire, J.; Spencer, R.; Rodriguez-Cardona, B.; Helton, A. M.; Barnes, R.; Argerich, A.; Haq, S.; Sullivan, P. L.; López-Lloreda, C.; Coble, A. A.; Daley, M.

2017-12-01

Anthropogenic activities are altering carbon and nitrogen concentrations in surface waters globally. The stoichiometry of carbon and nitrogen regulates important watershed biogeochemical cycles; however, controls on carbon and nitrogen ratios in aquatic environments are poorly understood. Here we use a multi-biome and global dataset (tropics to Arctic) of stream water chemistry to assess relationships between dissolved organic carbon (DOC) and nitrate, ammonium and dissolved organic nitrogen (DON), providing a new conceptual framework to consider interactions between DOC and the multiple forms of dissolved nitrogen. We found that across streams the total dissolved nitrogen (TDN) pool is comprised of very little ammonium and as DOC concentrations increase the TDN pool shifts from nitrate to DON dominated. This suggests that in high DOC systems, DON serves as the primary source of nitrogen. At the global scale, DOC and DON are positively correlated (r2 = 0.67) and the average C: N ratio of dissolved organic matter (molar ratio of DOC: DON) across our data set is approximately 31. At the biome and smaller regional scale the relationship between DOC and DON is highly variable (r2 = 0.07 - 0.56) with the strongest relationships found in streams draining the mixed temperate forests of the northeastern United States. DOC: DON relationships also display spatial and temporal variability including latitudinal and seasonal trends, and interactions with land-use. DOC: DON ratios correlated positively with gradients of energy versus nutrient limitation pointing to the ecological role (energy source versus nutrient source) that DON plays with stream ecosystems. Contrary to previous findings we found consistently weak relationships between DON and nitrate which may reflect DON's duality as an energy or nutrient source. Collectively these analyses demonstrate how gradients of DOC drive compositional changes in the TDN pool and reveal a high degree of variability in the C: N ratio

Molecular nitrogen fixation and nitrogen cycle in nature

Energy Technology Data Exchange (ETDEWEB)

Virtanen, A I

1952-01-01

The origin of nitrogen oxides in the atmosphere is discussed. Evidently only a small proportion of the nitrate-and nitrite-nitrogen found in the precipitation is formed through electric discharges from molecular nitrogen, photochemical nitrogen fixation being probably of greater importance. Formation of nitrate nitrogen through atmospheric oxidation of nitrous oxide (N/sub 2/O) evaporating from the soil is also considered likely. Determination of nitrogen compounds at different altitudes is indispensable for gaining information of the N/sub 2/-fixation in the atmosphere and, in general, of the origin of nitrogen oxides and their decomposition. International cooperation is needed for this as well as for the quantitative determination of the nitrogen compounds removed from the soil by leaching and brought by waters into the seas.

Regionalization of meso-scale physically based nitrogen modeling outputs to the macro-scale by the use of regression trees

Science.gov (United States)

Künne, A.; Fink, M.; Kipka, H.; Krause, P.; Flügel, W.-A.

2012-06-01

In this paper, a method is presented to estimate excess nitrogen on large scales considering single field processes. The approach was implemented by using the physically based model J2000-S to simulate the nitrogen balance as well as the hydrological dynamics within meso-scale test catchments. The model input data, the parameterization, the results and a detailed system understanding were used to generate the regression tree models with GUIDE (Loh, 2002). For each landscape type in the federal state of Thuringia a regression tree was calibrated and validated using the model data and results of excess nitrogen from the test catchments. Hydrological parameters such as precipitation and evapotranspiration were also used to predict excess nitrogen by the regression tree model. Hence they had to be calculated and regionalized as well for the state of Thuringia. Here the model J2000g was used to simulate the water balance on the macro scale. With the regression trees the excess nitrogen was regionalized for each landscape type of Thuringia. The approach allows calculating the potential nitrogen input into the streams of the drainage area. The results show that the applied methodology was able to transfer the detailed model results of the meso-scale catchments to the entire state of Thuringia by low computing time without losing the detailed knowledge from the nitrogen transport modeling. This was validated with modeling results from Fink (2004) in a catchment lying in the regionalization area. The regionalized and modeled excess nitrogen correspond with 94%. The study was conducted within the framework of a project in collaboration with the Thuringian Environmental Ministry, whose overall aim was to assess the effect of agro-environmental measures regarding load reduction in the water bodies of Thuringia to fulfill the requirements of the European Water Framework Directive (Bäse et al., 2007; Fink, 2006; Fink et al., 2007).

Effects of experimental nitrogen deposition on peatland carbon pools and fluxes: a modeling analysis

Science.gov (United States)

Wu, Y.; Blodau, C.; Moore, T. R.; Bubier, J. L.; Juutinen, S.; Larmola, T.

2014-07-01

Nitrogen (N) pollution of peatlands alters their carbon (C) balances, yet long-term effects and controls are poorly understood. We applied the model PEATBOG to analyze impacts of long-term nitrogen (N) fertilization on C cycling in an ombrotrophic bog. Simulations of summer gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosystem exchange (NEE) were evaluated against 8 years of observations and extrapolated for 80 years to identify potential effects of N fertilization and factors influencing model behavior. The model successfully simulated moss decline and raised GEP, ER and NEE on fertilized plots. GEP was systematically overestimated in the model compared to the field data due to high tolerance of Sphagnum to N deposition in the model. Model performance regarding the 8 year response of GEP and NEE to N was improved by introducing an N content threshold shifting the response of photosynthesis capacity to N content in shrubs and graminoids from positive to negative at high N contents. Such changes also eliminated the competitive advantages of vascular species and led to resilience of mosses in the long-term. Regardless of the large changes of C fluxes over the short-term, the simulated GEP, ER and NEE after 80 years depended on whether a graminoid- or shrub-dominated system evolved. When the peatland remained shrub-Sphagnum dominated, it shifted to a C source after only 10 years of fertilization at 6.4 g N m-2 yr-1, whereas this was not the case when it became graminoid-dominated. The modeling results thus highlight the importance of ecosystem adaptation and reaction of plant functional types to N deposition, when predicting the future C balance of N-polluted cool temperate bogs.

Effects of experimental nitrogen deposition on peatland carbon pools and fluxes: a modelling analysis

Science.gov (United States)

Wu, Y.; Blodau, C.; Moore, T. R.; Bubier, J.; Juutinen, S.; Larmola, T.

2015-01-01

Nitrogen (N) pollution of peatlands alters their carbon (C) balances, yet long-term effects and controls are poorly understood. We applied the model PEATBOG to explore impacts of long-term nitrogen (N) fertilization on C cycling in an ombrotrophic bog. Simulations of summer gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosystem exchange (NEE) were evaluated against 8 years of observations and extrapolated for 80 years to identify potential effects of N fertilization and factors influencing model behaviour. The model successfully simulated moss decline and raised GEP, ER and NEE on fertilized plots. GEP was systematically overestimated in the model compared to the field data due to factors that can be related to differences in vegetation distribution (e.g. shrubs vs. graminoid vegetation) and to high tolerance of vascular plants to N deposition in the model. Model performance regarding the 8-year response of GEP and NEE to N input was improved by introducing an N content threshold shifting the response of photosynthetic capacity (GEPmax) to N content in shrubs and graminoids from positive to negative at high N contents. Such changes also eliminated the competitive advantages of vascular species and led to resilience of mosses in the long-term. Regardless of the large changes of C fluxes over the short-term, the simulated GEP, ER and NEE after 80 years depended on whether a graminoid- or shrub-dominated system evolved. When the peatland remained shrub-Sphagnum-dominated, it shifted to a C source after only 10 years of fertilization at 6.4 g N m-2 yr-1, whereas this was not the case when it became graminoid-dominated. The modelling results thus highlight the importance of ecosystem adaptation and reaction of plant functional types to N deposition, when predicting the future C balance of N-polluted cool temperate bogs.

Hippotherapy on postural balance in the sitting position of children with cerebral palsy - Longitudinal study.

Science.gov (United States)

Moraes, Andréa Gomes; Copetti, Fernando; Ângelo, Vera Regina; Chiavoloni, Luana; de David, Ana Cristina

2018-06-11

To verify the effects of 12, 24, 36 hippotherapy sessions over time on postural balance while sitting in children with cerebral palsy as well the effects of treatment after one interruption period of 45 days. Hippotherapy program with a twice-weekly treatment with a total of 13 children aged 5-10 years old. Measurements of postural balance during sitting were performed using the AMTI AccuSway Plus platform. There was a statistically significant reduction in mediolateral and anteroposterior sway after the first 12 hippotherapy sessions, and further significant sway reduction occurred as the treatment progressed. Changes in the center of pressure displacement velocity variable began to occur after 24 sessions. Seated postural balance improved in children with cerebral palsy, as evidenced by lower COP displacement, particularly after a greater number of sessions. After the last evaluations, when completing 36 sessions of hippotherapy, it was verified that the improvements to the postural balance continued to occur. Therefore, further studies with a longer treatment period may help to clarify if, at some point, there is stabilization in the improvement of postural balance. Furthermore, it is important to analyze the impact of hippotherapy on functional activities over time.

Behavior and Release of Nitrogen at Mines and Quarries in Nordic Conditions

Science.gov (United States)

Karlsson, Teemu; Neitola, Raisa; Jermakka, Johannes; Merta, Elina; Mroueh, Ulla-Maija

2015-04-01

The increased extraction of mineral resources and mining activities creates added pressure on the environmental issues and a proper water management in mining areas in Finland. Among others, nitrogen compounds released from explosives or from mining processes can have a detrimental effect on the environment. Thus, this project aimed at comprehensive understanding on the nitrogen issue in the extractive industry. The project collected essential data on nitrogen compounds present in the environments of mines and quarries, and generated better understanding of the discharge and behaviour of nitrogen compounds in mining areas. The sources and balances of explosives-originated nitrogen compounds at mines and quarries of different sizes were investigated and compared. Additionally, the focus was in 'nitrogen smudging' problem of waste rocks and the intensity, as well as evolution and chemical characteristics of their nitrogen contamination. According to the results, the total load of potential nitrogen to the environment depends on the scale and type of the activity as well as the type of explosives used. The main emission sources of nitrogen are process and dewatering waters. A lysimeter study showed that the explosives originated nitrogen content of left over stones from natural stone quarrying is relatively low and ca. half of the nitrogen is leached within the first weeks after detonation. The "nitrogen smudging" of natural stone quarrying left over stones is relatively low to begin with and enhanced by the rapid flushing by rainwater, thus the residues of explosives should not be considered to prevent the utilization of otherwise mineralogically inert waste rocks of good technical quality. The overall nitrogen management should take into account the background concentrations and sensitivity of the local ecosystem. The research project "Solution for Control of Nitrogen Discharges at Mines and Quarries, (MINIMAN)" was realized during years 2012-2014 as a cooperative

High-capacitance supercapacitors using nitrogen-decorated porous carbon derived from novolac resin containing peptide linkage

Energy Technology Data Exchange (ETDEWEB)

Kim, Yong Jung [Institute of Carbon Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan); Jang, In Young; Park, Ki Chul; Jung, Yong Chae; Oka, Takuyuki [Department of Electric and Electronic Engineering, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan); Iinou, Satoshi [MEFS, Co. Ltd. Choei Nagano, Higasiguchi Bldg, 2F, 1000-1 Gentakubo, Kurita, Nagano 380-0921 (Japan); Komori, Yasuhiro; Kozutsumi, Toshihiko; Hashiba, Takashi [SHOWA HIGHPOLYMER, Co., Ltd. 1021 Tomizuka-cho, Isesaki-City, Gunma 372-0833 (Japan); Kim, Yoong Ahm, E-mail: yak@endomoribu.shinshu-u.ac.j [Department of Electric and Electronic Engineering, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan); Endo, Morinobu [Institute of Carbon Science and Technology, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan)] [Department of Electric and Electronic Engineering, Faculty of Engineering, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan)

2010-08-01

We fabricated nitrogen-decorated porous carbon exhibiting high capacitance per unit volume and unit weight via chemical activation of novolac resin containing peptide linkage. The porosity and the amount of nitrogen atoms were controlled by changing the molecular weight of novolac resin, the added amount of potassium hydroxide, or both. After chemical activation, positively charged nitrogen atoms (i.e., pyridine/pyrrole) at 400.3 eV in photoemission spectra contributed to both a shift in the point of zero charge toward negative potential and the generation of pseudocapacitance. Suitably developed pores and the positively charged nitrogen atoms make nitrogen-decorated novolac resin-derived porous carbon a promising material for electrodes in high-performance supercapacitors.

Restoring Cytokine Balance in HIV-Positive Individuals with Low CD4 T Cell Counts

Science.gov (United States)

Valdivia, Anddre; Ly, Judy; Gonzalez, Leslie; Hussain, Parveen; Saing, Tommy; Islamoglu, Hicret; Pearce, Daniel; Ochoa, Cesar

2017-01-01

Abstract HIV infects and destroys CD4+ T cells leading to a compromised immune system. In a double-blinded study, a group of HIV-infected individuals with CD4+ T cell counts below 350 cells/mm3 were given either an empty liposomal supplement or a liposomal glutathione (L-GSH) supplement to take over a 3-month period. Baseline measurements in HIV-positive subjects show a significant decrease in levels of interleukin (IL)-12, IL-2, and interferon (IFN)-γ, along with a substantial increase in the levels of IL-6, IL-10, transforming growth factor (TGF)-β, and free radicals, compared to healthy individuals. Supplementation of HIV-positive subjects with L-GSH for 3 months resulted in a notable increase in the levels of IL-12, IL-2, and IFN-γ, with a concomitant decrease in the levels of IL-6, IL-10, and free radicals, and stabilization in the levels of TGF-β, IL-1, and IL-17, compared to their placebo counterparts. Levels of free radicals in CD4+ T cells stabilized, while GSH levels increased in the treatment group. Those in the placebo group showed no significant difference throughout the study. In summary, supplementation with L-GSH in HIV-infected individuals with CD4+ T cell counts below 350 cells/mm3 can help restore redox homeostasis and cytokine balance, therefore aiding the immune system to control opportunistic infections. PMID:28398068

Parameterization of Nitrogen Limitation for a Dynamic Ecohydrological Model: a Case Study from the Luquillo Critical Zone Observatory

Science.gov (United States)

Bastola, S.; Bras, R. L.

2017-12-01

Feedbacks between vegetation and the soil nutrient cycle are important in ecosystems where nitrogen limits plant growth, and consequently influences the carbon balance in the plant-soil system. However, many biosphere models do not include such feedbacks, because interactions between carbon and the nitrogen cycle can be complex, and remain poorly understood. In this study we coupled a nitrogen cycle model with an eco-hydrological model by using the concept of carbon cost economics. This concept accounts for different "costs" to the plant of acquiring nitrogen via different pathways. This study builds on tRIBS-VEGGIE, a spatially explicit hydrological model coupled with a model of photosynthesis, stomatal resistance, and energy balance, by combining it with a model of nitrogen recycling. Driven by climate and spatially explicit data of soils, vegetation and topography, the model (referred to as tRIBS-VEGGIE-CN) simulates the dynamics of carbon and nitrogen in the soil-plant system; the dynamics of vegetation; and different components of the hydrological cycle. The tRIBS-VEGGIE-CN is applied in a humid tropical watershed at the Luquillo Critical Zone Observatory (LCZO). The region is characterized by high availability and cycling of nitrogen, high soil respiration rates, and large carbon stocks.We drive the model under contemporary CO2 and hydro-climatic forcing and compare results to a simulation under doubling CO2 and a range of future climate scenarios. The results with parameterization of nitrogen limitation based on carbon cost economics show that the carbon cost of the acquisition of nitrogen is 14% of the net primary productivity (NPP) and the N uptake cost for different pathways vary over a large range depending on leaf nitrogen content, turnover rates of carbon in soil and nitrogen cycling processes. Moreover, the N fertilization simulation experiment shows that the application of N fertilizer does not significantly change the simulated NPP. Furthermore, an

How body balance influences political party evaluations: A wii balance board study

NARCIS (Netherlands)

K. Dijkstra (Katinka); A. Eerland (Anita); J.M. Zijlmans (Mark); L.S. Post (Lysanne)

2012-01-01

textabstractEmbodied cognition research has shown how actions or body positions may affect cognitive processes, such as autobiographical memory retrieval or judgments. The present study examined the role of body balance (to the left or the right) in participants on their attributions to political

Optimal Plant Carbon Allocation Implies a Biological Control on Nitrogen Availability

Science.gov (United States)

Prentice, I. C.; Stocker, B. D.

2015-12-01

The degree to which nitrogen availability limits the terrestrial C sink under rising CO2 is a key uncertainty in carbon cycle and climate change projections. Results from ecosystem manipulation studies and meta-analyses suggest that plant C allocation to roots adjusts dynamically under varying degrees of nitrogen availability and other soil fertility parameters. In addition, the ratio of biomass production to GPP appears to decline under nutrient scarcity. This reflects increasing plant C exudation into the soil (Cex) with decreasing nutrient availability. Cex is consumed by an array of soil organisms and may imply an improvement of nutrient availability to the plant. Thus, N availability is under biological control, but incurs a C cost. In spite of clear observational support, this concept is left unaccounted for in Earth system models. We develop a model for the coupled cycles of C and N in terrestrial ecosystems to explore optimal plant C allocation under rising CO2 and its implications for the ecosystem C balance. The model follows a balanced growth approach, accounting for the trade-offs between leaf versus root growth and Cex in balancing C fixation and N uptake. We assume that Cex is proportional to root mass, and that the ratio of N uptake (Nup) to Cex is proportional to inorganic N concentration in the soil solution. We further assume that Cex is consumed by N2-fixing processes if the ratio of Nup:Cex falls below the inverse of the C cost of N2-fixation. Our analysis thereby accounts for the feedbacks between ecosystem C and N cycling and stoichiometry. We address the question of how the plant C economy will adjust under rising atmospheric CO2 and what this implies for the ecosystem C balance and the degree of N limitation.

The Effects of Nitrogen Gas on Microstructural and Mechanical Properties of TIG Welded S32205 Duplex Stainless Steel

Directory of Open Access Journals (Sweden)

Aziz Barış Başyiğit

2018-04-01

Full Text Available Duplex stainless steels are gaining greater interest due to their increasing amounts of application fields. Accordingly, there is a need for awareness of problems associated with improper microstructural distributions such as δ-ferrite (delta-ferrite, austenite and other important intermetallic phases that may form in these steel weldments. Since δ-ferrite versus austenite ratio profoundly influences corrosion and mechanical properties, optimum δ-ferrite ratios must be kept approximately within 35–65 vol % and balance austenite to maintain satisfactory corrosion and mechanical properties on welding of these steels. Cooling rates of welds and alloying elements in base metal are the major factors that determine the final microstructure of these steels. In this work, 3 mm thickness of 2205 duplex stainless-steel plates were TIG (Tungsten Inert Gas welded with various amounts of nitrogen gas added to argon shielding gas. Specimens were joined within the same welding parameters and cooling conditions. As nitrogen is a potential austenite stabilizer and an interstitial solid solution hardener, the effects of nitrogen on mechanical properties such as hardness profiles, grain sizes and microstructural modifications are investigated thoroughly by changing the welding shielding gas compositions. Increasing the nitrogen content in argon shielding gas also increases the amount of austenitic phase while δ-ferrite ratios decreases. Nitrogen spherodized the grains of austenitic structure much more than observed in δ-ferrite. The strength values of specimens that welded with the addition of nitrogen gas into the argon shielding gas are increased more in both austenitic and delta-ferritic structure as compared to specimens that welded with plain argon shielding gas. The addition of 1 vol % of nitrogen gas into argon shielding gas provided the optimum phase balance of austenite and δ-ferrite in S32205 duplex stainless-steel TIG-welded specimens.

A Case Study and Balance Sheet Approach to Unemployment.

Science.gov (United States)

Hesketh, Beryl; And Others

1987-01-01

Describes positive and negative aspects of employment and unemployment in a balance sheet framework. Discusses the value of the balance sheet approach in understanding individual differences in reactions to unemployment. (Author/KS)

Stable Isotopes of Nitrogen in Fossil Cladoceran Exoskeletons: Implications for Nitrogen Sources in the Central Baltic Sea During the Past Century

Science.gov (United States)

Struck, Ulrich; Voss, Maren; von Bodungen, Bodo; Mumm, Nicolai

The ratios of stable nitrogen isotopes were analysed in zooplankton exoskeletons extracted from dated sediment cores from the Gotland Basin of the central Baltic Sea. Combined with results on δ15N of bulk sediment, organic carbon concentrations, and abundances of exoskeletons of Bosminalongispinamaritima in the sediment, the data are used to evaluate significant sources of nitrogen in the food web over the past century. Nitrogen isotopic composition of bulk sediments ranges from 2.5 to 4.5ö, that of exokeletons varies between 0.4 and 6.2ö. The two are positively correlated. A marked increase in the abundance of Bosmina since 1965 (from less than 500 specimen to more than 5000 specimencm3 of sediment) is correlated with a significant increase in sedimentary organic carbon concentrations (from 4% to more than 10%). The isotopic data do not identify increased land-derived nitrate as the dominant nitrogen source fuelling the increase. Instead, we postulate that nitrogen fixation by diazotrophic bacteria has been one of the larger sources of nitrogen in the Baltic Sea, as it is today.

How body balance influences political party evaluations. A Wii balance board study.

Directory of Open Access Journals (Sweden)

Katinka eDijkstra

2012-12-01

Full Text Available Embodied cognition research has shown how actions or body positions may affect cognitive processes, such as autobiographical memory retrieval or judgments. The present study examined the role of body balance (to the left or the right in participants on their attributions to political parties. Participants thought they stood upright on a Wii™ Balance Board, while they were actually slightly tilted to the left or the right. Participants then ascribed fairly general political statements to one of ten political parties that are represented in the Dutch House of Representatives. Results showed a significant interaction of congruent leaning direction with left- or right wing party attribution. When the same analyses were performed with the political parties being divided into affiliations to the right, center, and left based on participants’ personal opinions rather than a ruling classification, no effects were found. The study provides evidence that conceptual metaphors are activated by manipulating body balance implicitly. Moreover, people’s judgments may be colored by seemingly trivial circumstances such as standing slightly out of balance.

How body balance influences political party evaluations: a wii balance board study.

Science.gov (United States)

Dijkstra, Katinka; Eerland, Anita; Zijlmans, Josjan; Post, Lysanne S

2012-01-01

Embodied cognition research has shown how actions or body positions may affect cognitive processes, such as autobiographical memory retrieval or judgments. The present study examined the role of body balance (to the left or the right) in participants on their attributions to political parties. Participants thought they stood upright on a Wii(™) Balance Board, while they were actually slightly tilted to the left or the right. Participants then ascribed fairly general political statements to one of 10 political parties that are represented in the Dutch House of Representatives. Results showed a significant interaction of congruent leaning direction with left- or right-wing party attribution. When the same analyses were performed with the political parties being divided into affiliations to the right, center, and left based on participants' personal opinions rather than a ruling classification, no effects were found. The study provides evidence that conceptual metaphors are activated by manipulating body balance implicitly. Moreover, people's judgments may be colored by seemingly trivial circumstances such as standing slightly out of balance.

Economic Benefits of Aerobic Rice Grown Using Integrated Nitrogen Management

Directory of Open Access Journals (Sweden)

Nyle A. Pardillo

2017-11-01

Full Text Available This study focuses in the effect of integrated nitrogen management to the yield and economic benefits of aerobic rice. This will help farmers to identify which of the two management technique to use to save costs while profit is high. A split plot experiment in Randomized Complete Block design is used with two main treatments and four sub treatments. Main treatments are the use of integrated nitrogen management and an application of synthetic nitrogen fertilizer. Sub treatments are the different rates of nitrogen fertilizer from 0 as control, 90, 120 and 150 kg N ha-1 . Data are consolidated and analyzed using the ANOVA of SAS 9.3 statistical tool and comparison means at 5% significance level in Duncan Multiple Range Test. Grain yield, income, costs, profit and return on expenses are the data gathered. There is an increasing yield from control to 120 kg N ha-1 and started to decline at 150 kg N ha-1 because optimum level reached at 120 kg N ha-1 . Significant increased in yield was observed in plants applied with integrated nitrogen management at 120 kg N ha-1 compared to plants applied with synthetic nitrogen due to release of nitrogen that contributed to the yield of aerobic rice. However, plants applied of 90 kg N ha-1 synthetic nitrogen gives significant yield increased compared to plants with integrated nitrogen management. Yield was subjected to economic analysis using gross income, costs and profit and return on expenses. Plants applied with synthetic nitrogen at 90 kg N ha-1 resulted to high income due to lower costs of fertilizer inputs and only treatment that has a positive return on expenses at 3.2% while other treatments have a negative remarks. This will lead to a conclusion that 90 kg N ha-1 is the optimum level of nitrogen that can give high yield and positive return on expenses that farmers will benefited.

Light-dark (12:12) cycle of carbon and nitrogen metabolism in Crocosphaera watsonii WH8501: relation to the cell cycle.

Science.gov (United States)

Dron, Anthony; Rabouille, Sophie; Claquin, Pascal; Le Roy, Bertrand; Talec, Amélie; Sciandra, Antoine

2012-04-01

This study provides with original data sets on the physiology of the unicellular diazotrophic cyanobacterium Crocosphaera watsonii WH8501, maintained in continuous culture in conditions of obligate diazotrophy. Cultures were exposed to a 12:12 light-dark regime, representative of what they experience in nature and where growth is expected to be balanced. Nitrogen and carbon metabolism were monitored at high frequency and their dynamics was compared with the cell cycle. Results reveal a daily cycle in the physiological and biochemical parameters, tightly constrained by the timely decoupled processes of N(2) fixation and carbon acquisition. The cell division rate increased concomitantly to carbon accumulation and peaked 6 h into the light. The carbon content reached a maximum at the end of the light phase. N(2) fixation occurred mostly during the dark period and peaked between 9 and 10 h into the night, while DNA synthesis, reflected by DNA fluorescence, increased until the end of the night. Consequently, cells in G1- and S-phases present a marked decrease in their C:N ratio. Nitrogen acquisition through N(2) fixation exceeded 1.3- to 3-fold the nitrogen requirements for growth, suggesting that important amounts of nitrogen are excreted even under conditions supposed to favour balanced, carbon and nitrogen acquisitions. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

Electronic structure of graphene nanoribbons doped with nitrogen atoms: a theoretical insight.

Science.gov (United States)

Torres, A E; Fomine, S

2015-04-28

The electronic structure of graphene nanoribbons doped with a graphitic type of nitrogen atoms has been studied using B3LYP, B2PLYP and CAS methods. In all but one case the restricted B3LYP solutions were unstable and the CAS calculations provided evidence for the multiconfigurational nature of the ground state with contributions from two dominant configurations. The relative stability of the doped nanoribbons depends mostly on the mutual position of the dopant atoms and notably less on the position of nitrogen atoms within the nanoribbon. N-graphitic doping affects cationic states much more than anionic ones due the participation of the nitrogen atoms in the stabilization of the positive charge, resulting in a drop in ionization energies (IPs) for N-graphitic doped systems. Nitrogen atoms do not participate in the negative charge stabilization of anionic species and, therefore, the doping does not affect the electron affinities (EAs). The unrestricted B3LYP method is the method of choice for the calculation of IPs and EAs. Restricted B3LYP and B2PLYP produces unreliable results for both IPs and EAs while CAS strongly underestimates the electron affinities. This is also true for the reorganization energies where restricted B3LYP produces qualitatively incorrect results. Doping changes the reorganization energy of the nanoribbons; the hole reorganization energy is generally higher than the corresponding electron reorganization energy due to the participation of nitrogen atoms in the stabilization of the positive charge.

Nitrogen

Science.gov (United States)

Apodaca, Lori E.

2013-01-01

The article presents an overview of the nitrogen chemical market as of July 2013, including the production of ammonia compounds. Industrial uses for ammonia include fertilizers, explosives, and plastics. Other topics include industrial capacity of U.S. ammonia producers CF Industries Holdings Inc., Koch Nitrogen Co., PCS Nitrogen, Inc., and Agrium Inc., the impact of natural gas prices on the nitrogen industry, and demand for corn crops for ethanol production.

A continuous-flow system for measuring in vitro oxygen and nitrogen metabolism in separated stream communities

DEFF Research Database (Denmark)

Prahl, C.; Jeppesen, E.; Sand-Jensen, Kaj

1991-01-01

on the stream bank, consists of several macrophyte and sediment chambers equipped with a double-flow system that ensures an internal water velocity close to that in the stream and which, by continuously renewing the water, mimics diel fluctuation in stream temperature and water chemistry. Water temperature...... production and dark respiration occurred at similar rates (6-7g O2 m-2 day-1), net balance being about zero. Inorganic nitrogen was consumed both by the sediment and to a greater extent by the macrophytes, the diel average consumption being 1g N m-2 day-1. 3. The sum of the activity in the macrophyte...... and sediment chambers corresponded to the overall activity of the stream section as determined by upstream/downstream mass balance. This indicates that the results obtained with the continuous-flow chambers realistically describe the oxygen and the nitrogen metabolism of the stream....

Sport-specific balance.

Science.gov (United States)

Zemková, Erika

2014-05-01

This review includes the latest findings based on experimental studies addressing sport-specific balance, an area of research that has grown dramatically in recent years. The main objectives of this work were to investigate the postural sway response to different forms of exercise under laboratory and sport-specific conditions, to examine how this effect can vary with expertise, and to provide examples of the association of impaired balance with sport performance and/or increasing risk of injury. In doing so, sports where body balance is one of the limiting factors of performance were analyzed. While there are no significant differences in postural stability between athletes of different specializations and physically active individuals during standing in a standard upright position (e.g., bipedal stance), they have a better ability to maintain balance in specific conditions (e.g., while standing on a narrow area of support). Differences in magnitude of balance impairment after specific exercises (rebound jumps, repeated rotations, etc.) and mainly in speed of its readjustment to baseline are also observed. Besides some evidence on an association of greater postural sway with the increasing risk of injuries, there are many myths related to the negative influence of impaired balance on sport performance. Though this may be true for shooting or archery, findings have shown that in many other sports, highly skilled athletes are able to perform successfully in spite of increased postural sway. These findings may contribute to better understanding of the postural control system under various performance requirements. It may provide useful knowledge for designing training programs for specific sports.

Nutrient Mass Balance for the Mobile River Basin in Alabama, Georgia, and Mississippi

Science.gov (United States)

Harned, D. A.; Harvill, J. S.; McMahon, G.

2001-12-01

The source and fate of nutrients in the Mobile River drainage basin are important water-quality concerns in Alabama, Georgia, and Mississippi. Land cover in the basin is 74 percent forested, 16 percent agricultural, 2.5 percent developed, and 4 percent wetland. A nutrient mass balance calculated for 18 watersheds in the Mobile River Basin indicates that agricultural non-point nitrogen and phosphorus sources and urban non-point nitrogen sources are the most important factors associated with nutrients in the streams. Nitrogen and phosphorus inputs from atmospheric deposition, crop fertilizer, biological nitrogen fixation, animal waste, and point sources were estimated for each of the 18 drainage basins. Total basin nitrogen inputs ranged from 27 to 93 percent from atmospheric deposition (56 percent mean), 4 to 45 percent from crop fertilizer (25 percent mean), animal waste (8 percent mean), and 0.2 to 11 percent from point sources (3 percent mean). Total basin phosphorus inputs ranged from 10 to 39 percent from atmospheric deposition (26 percent mean), 7 to 51 percent from crop fertilizer (28 percent mean), 20 to 64 percent from animal waste (41 percent mean), and 0.2 to 11 percent from point sources (3 percent mean). Nutrient outputs for the watersheds were estimated by calculating instream loads and estimating nutrient uptake, or withdrawal, by crops. The difference between the total basin inputs and outputs represents nutrients that are retained or processed within the basin while moving from the point of use to the stream, or in the stream. Nitrogen output, as a percentage of the total basin nitrogen inputs, ranged from 19 to 79 percent for instream loads (35 percent mean) and from 0.01 to 32 percent for crop harvest (10 percent mean). From 53 to 87 percent (75 percent mean) of nitrogen inputs were retained within the 18 basins. Phosphorus output ranged from 9 to 29 percent for instream loads (18 percent mean) and from 0.01 to 23 percent for crop harvest (7

Local electron mean energy profile of positive primary streamer discharge with pin-plate electrodes in oxygen—nitrogen mixtures

International Nuclear Information System (INIS)

Sima Wen-Xia; Peng Qing-Jun; Yang Qing; Yuan Tao; Shi Jian

2013-01-01

Local electron mean energy (LEME) has a direct effect on the rates of collisional ionization of molecules and atoms by electrons. Electron-impact ionization plays an important role and is the main process for the production of charged particles in a primary streamer discharge. Detailed research on the LEME profile in a primary streamer discharge is extremely important for a comprehensive understanding of the local physical mechanism of a streamer. In this study, the LEME profile of the primary streamer discharge in oxygen-nitrogen mixtures with a pin-plate gap of 0.5 cm under an impulse voltage is investigated using a fluid model. The fluid model includes the electron mean energy density equation, as well as continuity equations for electrons and ions and Poisson's electric field equation. The study finds that, except in the initial stage of the primary streamer, the LEME in the primary streamer tip tends to increase as the oxygen-nitrogen mole ratio increases and the pressure decreases. When the primary streamer bridges the gap, the LEME in the primary streamer channel is smaller than the first ionization energies of oxygen and nitrogen. The LEME in the primary streamer channel then decreases as the oxygen-nitrogen mole ratio increases and the pressure increases. The LEME in the primary streamer tip is primarily dependent on the reduced electric field with mole ratios of oxygen-nitrogen given in the oxygen-nitrogen mixtures. (physics of gases, plasmas, and electric discharges)

Does shoot water status limit leaf expansion of nitrogen-deprived barley?

Science.gov (United States)

Dodd, I C; Munns, Rana; Passioura, J B

2002-08-01

The role of shoot water status in mediating the decline in leaf elongation rate of nitrogen (N)-deprived barley plants was assessed. Plants were grown at two levels of N supply, with or without the application of pneumatic pressure to the roots. Applying enough pressure (balancing pressure) to keep xylem sap continuously bleeding from the cut surface of a leaf allowed the plants to remain at full turgor throughout the experiments. Plants from which N was withheld required a greater balancing pressure during both day and night. This difference in balancing pressure was greater at high (2.0 kPa) than low (1.2 kPa) atmospheric vapour pressure deficit (VPD). Pressurizing the roots did not prevent the decline in leaf elongation rate induced by withholding N at either high or low VPD. Thus low shoot water status did not limit leaf growth of N-deprived plants.

Effects of Dietary Electrolyte Balance on Growth Performance, Nitrogen Metabolism and Some Blood Biochemical Parameters of Growing Rabbits

Directory of Open Access Journals (Sweden)

J. W. Li

2013-12-01

Full Text Available The effects of different dietary electrolyte balance (DEB on growth performance, nitrogen (N metabolism and some blood biochemical parameters were investigated in 2 to 3 months old growing rabbits. A total of 150 growing rabbits of 2 months age were randomly divided into five groups according to average body weight, with 30 rabbits in each group. The DEB levels of the five experimental diets were −154, −3.16, +201, +347, and +500 meq/kg of dry matter (DM, respectively. There was a 7-d adaptation period and a 23-d experimental period. The results showed that the DEB levels had a quadratic affect on the average daily feed intake (ADFI (p<0.001. The greatest ADFI was achieved when the DEB level was +201 meq/kg DM. Fecal N (FN content linearly decreased (0.047, while digestible N (DN, retained N (RN, efficiency of intake N converted into digestible N (DN/IN and the efficiency of intake N converted into retained N (RN/IN linearly increased with the DEB increase (0.020, 0.004, 0.021, and 0.049, respectively. Serum phosphorus (P ion content linearly increased with the DEB increase (p = 0.036. The DEB had a quadratic relationship with serum anion gap (AG (p = 0.002 and serum parathyroid hormone (PTH content (p = 0.016. The DEB levels quadratically affected base excess (BE in the plasma (p<0.001. In conclusion, the DEB unaffected growth performance but affected feed intake, N metabolism and some blood biochemical parameters of growing rabbits.

The effect of balance training on cervical sensorimotor function and neck pain.

Science.gov (United States)

Beinert, Konstantin; Taube, Wolfgang

2013-01-01

The authors' aim was to evaluate the effect of balance training on cervical joint position sense in people with subclinical neck pain. Thirty-four participants were randomly assigned to balance training or to stay active. Sensorimotor function was determined before and after 5 weeks of training by assessing the ability to reproduce the neutral head position and a predefined rotated head position. After balance training, the intervention group showed improved joint repositioning accuracy and decreased pain whereas no effects were observed in the control group. A weak correlation was identified between reduced neck pain intensity and improved joint repositioning. The present data demonstrate that balance training can effectively improve cervical sensorimotor function and decrease neck pain intensity.

Behaviour and fate of animal waste nitrogen and soluble ions in the agricultural environment with particular reference to rice. Part of a coordinated programme on agricultural nitrogen residues with particular reference to their conservation as fertilizers and behaviour as potential pollutants

International Nuclear Information System (INIS)

Kobayashi, H.

1976-11-01

The fate of residual nitrogen and its fertilizer efficiency following application to rice plants in pots under controlled laboratory conditions have been studied. Nitrogen was applied as 15 N labelled fecal waste from goat and hog, and as chemical fertilizer (ammonium sulphate) respectively. Animal waste nitrogen was less effective than ammonium sulphate nitrogen in terms of rice yield. On the other hand residual nitrogen in the high soil layers was much higher for the organic nitrogen application and there appeared to be lower losses by volatilization (20-30% for animal waste N, 30-40% for ammonium sulphate nitrogen). Leaching losses were minimal and similar for both kinds of N-application (ca. 1%). Similar results were obtained under field conditions with alluvial, and ''sandy'' soils respectively. Plant recovery of N was greater from ammonium sulphate than from animal waste but overall losses in total balance studies appeared greater for N applied as ammonium sulphate under otherwise comparable conditions (30-40% of N applied as ammonium sulphate and 19-32% of N applied as fecal waste)

Competitive balance and nitrogen losses from three grass species (Arrhenatherum elatius, Calamagrostis epigejos, Festuca ovina)

Czech Academy of Sciences Publication Activity Database

Tůma, Ivan; Holub, Josef; Fiala, Karel

2005-01-01

Roč. 60, č. 4 (2005), s. 417-422 ISSN 0006-3088 R&D Projects: GA ČR(CZ) GA206/02/0581 Institutional research plan: CEZ:AV0Z60050516 Keywords : allocation * nitrogen requirement * relative yield Subject RIV: EF - Botanics Impact factor: 0.240, year: 2005

Needle-Age Related Variability in Nitrogen, Mobile Carbohydrates, and δ13C within Pinus koraiensis Tree Crowns

Science.gov (United States)

Yan, Cai-Feng; Han, Shi-Jie; Zhou, Yu-Mei; Wang, Cun-Guo; Dai, Guan-Hua; Xiao, Wen-Fa; Li, Mai-He

2012-01-01

For both ecologists and physiologists, foliar physioecology as a function of spatially and temporally variable environmental factors such as sunlight exposure within a tree crown is important for understanding whole tree physiology and for predicting ecosystem carbon balance and productivity. Hence, we studied concentrations of nitrogen (N), non-structural carbohydrates (NSC = soluble sugars + starch), and δ13C in different-aged needles within Pinus koraiensis tree crowns, to understand the needle age- and crown position-related physiology, in order to test the hypothesis that concentrations of N, NSC, and δ13C are needle-age and crown position dependent (more light, more photosynthesis affecting N, NSC, and δ13C), and to develop an accurate sampling strategy. The present study indicated that the 1-yr-old needles had significantly higher concentration levels of mobile carbohydrates (both on a mass and an area basis) and Narea (on an area basis), as well as NSC-N ratios, but significantly lower levels of Nmass (on a mass basis) concentration and specific leaf area (SLA), compared to the current-year needles. Azimuthal (south-facing vs. north-facing crown side) effects were found to be significant on starch [both on a mass (STmass) and an area basis (STarea)], δ13C values, and Narea, with higher levels in needles on the S-facing crown side than the N-facing crown side. Needle Nmass concentrations significantly decreased but needle STmass, STarea, and δ13C values significantly increased with increasing vertical crown levels. Our results suggest that the sun-exposed crown position related to photosynthetic activity and water availability affects starch accumulation and carbon isotope discrimination. Needle age associated with physiological activity plays an important role in determining carbon and nitrogen physiology. The present study indicates that across-scale sampling needs to carefully select tissue samples with equal age from a comparable crown position

Human stick balancing: Tuning Lèvy flights to improve balance control

Science.gov (United States)

Cabrera, Juan Luis; Milton, John G.

2004-09-01

State-dependent, or parametric, noise is an essential component of the neural control mechanism for stick balancing at the fingertip. High-speed motion analysis in three dimensions demonstrates that the controlling movements made by the fingertip during stick balancing can be described by a Lévy flight. The Lévy index, α, is approximately 0.9; a value close to optimal for a random search. With increased skill, the index α does not change. However, the tails of the Lévy distribution become broader. These observations suggest a Lévy flight that is truncated by the properties of the nervous and musculoskeletal system; the truncation decreasing as skill level increases. Measurements of the cross-correlation between the position of the tip of the stick and the fingertip demonstrate that the role of closed-loop feedback changes with increased skill. Moreover, estimation of the neural latencies for stick balancing show that for a given stick length, the latency increases with skill level. It is suggested that the neural control for stick balancing involves a mechanism in which brief intervals of consciously generated, corrective movements alternate with longer intervals of prediction-free control. With learning the truncation of the Lévy flight becomes better optimized for balance control and hence the time between successive conscious corrections increases. These observations provide the first evidence that changes in a Lévy flight may have functional significance for the nervous system. This work has implications for the control of balancing problems ranging from falling in the elderly to the design of two-legged robots and earthquake proof buildings.

Nitrogen removal from concentrated latex wastewater by land treatment

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Vikanda Thongnuekhang

2004-05-01

Full Text Available Most of the concentrated latex factories in the South of Thailand discharge treated wastewater that contains high level of nitrogen to a nearby river or canals leading to a water pollution problem. A study of land treatment system was conducted to treat and utilize nitrogen in treated wastewater from the concentrated latex factory. The experimental pilot-scale land treatment system was constructed at the Faculty of Engineering, Prince of Songkla University, Hat Yai Campus. It consisted of water convolvulus (Ipomea aquatica, I. Reptans, tropical carpet grass (Axonopus compresus (Swartz Beav. and control unit (no plantation. The treated wastewater from the stabilization pond system of the selected concentrated latex factoryin Songkhla was used to irrigate each experimental unit. Influent and effluent from the experimental units were analyzed for TKN, NH3-N, Org-N, NO3 --N, NO2 --N, BOD5, sulfate, pH and EC. The land treatment system resulted a high removal efficiency for nitrogen. Tropical carpet grass provided higher removal efficiency than other units for all parameters. The removal efficiency of water convolvulus and control unit were not significantly different. The average removal efficiency of TKN, NH3-N, Org-N, BOD5 and sulfate for tropical carpet grass unit were 92, 97, 61, 88 and 52%, for water convolvulus unit were 75, 80, 43, 41 and 30%, and for control unit were 74, 80, 41, 31 and 28%, respectively. Mass balance of nitrogen transformation was conducted. It revealed that plant uptake was the major mechanism for nitrogen removal in land treatment.

Fate of fertilizer nitrogen in soil-plant system under irrigating condition. Pt.1: Effect of nitrogen level

International Nuclear Information System (INIS)

Chen Qing; Wen Xianfang; Zheng Xingyun; Pan Jiarong

1997-01-01

Three nitrogen fertilization levels including optimum rate of nitrogen applied (N1.0, 150 kg N·ha -1 ), 150% of optimum rate (N1.5, 225 kg N·ha -1 ) and 50% of optimum rate (N0.5, 75 kg N·ha -1 ) were selected to determine the fate of nitrogen in soil plant system by 15 N technique in 1994∼1995 field experiment which was conducted in Shijiazhuang. The results showed that under irrigated condition the nitrogen use efficiencies (NUE) of ammonium bicarbonate by winter wheat in fertilized treatments were 38.5%, 32.3% and 22.4% respectively, while the highest NUE of winter wheat was found in N0.5 treatment due to a relatively high fertility. The highest yield (6.8 x 10 3 kg grain·ha -1 , 14.7 x 10 3 kg top·ha -1 ) was obtained in N1.0 treatment, but nitrogen uptake and grain yield in N1.5 treatment were lower than those of other fertilizer treatments and there was no significant difference between N0.0 and N1.5 in grain yield. the highest residue of fertilizer N was determined in N1.5 treatment, of which 46% existed in the top layer of the soil (0∼50 cm). There was no significant difference in residual fertilizer N in soil between the other two treatments (31.28% in N0.5, 31.12% in N1.0). In 15 N balance calculation, the unaccounted part of applied N which was leaching down 50 cm in the soil profile as nitrate or gaseous loss through volatilization, denitrification were 30.20%, the soil profile as nitrate or gaseous loss through volatilization, denitrification were 30.20%, 36.56%, 31.25% in N0.5, N1.5 treatments, respectively. It is very important to control residual N in order to prevent N pollution and promote the growth of next crop

Effect of storage conditions on losses and crop utilization of nitrogen from solid cattle manure

NARCIS (Netherlands)

Shah, G.M.; Shah, G.A.; Groot, J.C.J.; Oenema, O.; Raza, A.S.; Lantinga, E.A.

2016-01-01

The objectives of the present study were to quantify the effects of contrasting methods for storing solid cattle manure on: (i) total carbon (C) and nitrogen (N) balances during storage, and (ii) crop apparent N recovery (ANR) following manure application to arable land, with maize as a test

Synergistic dynamics of nitrogen and phosphorous influences lipid productivity in Chlorella minutissima for biodiesel production.

Science.gov (United States)

Arora, Neha; Patel, Alok; Pruthi, Parul A; Pruthi, Vikas

2016-08-01

The study synergistically optimized nitrogen and phosphorous concentrations for attainment of maximum lipid productivity in Chlorella minutissima. Nitrogen and phosphorous limited cells (N(L)P(L)) showed maximum lipid productivity (49.1±0.41mg/L/d), 1.47 folds higher than control. Nitrogen depletion resulted in reduced cell size with large sized lipid droplets encompassing most of the intracellular space while discrete lipid bodies were observed under nitrogen sufficiency. Synergistic N/P starvations showed more prominent effect on photosynthetic pigments as to individual deprivations. Phosphorous deficiency along with N starvation exhibited 17.12% decline in carbohydrate while no change in nitrogen sufficient cells were recorded. The optimum N(L)P(L) concentration showed balance between biomass and lipid by maintaining intermediate cell size, pigments, carbohydrate and proteins. FAME profile showed C14-C18 carbon chains in N(L)P(L) cells with biodiesel properties comparable to plant oil methyl esters. Hence, synergistic N/P limitation was effective for enhancing lipid productivity with reduced consumption of nutrients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Toward a nitrogen footprint calculator for Tanzania

Science.gov (United States)

Hutton, Mary Olivia; Leach, Allison M.; Leip, Adrian; Galloway, James N.; Bekunda, Mateete; Sullivan, Clare; Lesschen, Jan Peter

2017-03-01

We present the first nitrogen footprint model for a developing country: Tanzania. Nitrogen (N) is a crucial element for agriculture and human nutrition, but in excess it can cause serious environmental damage. The Sub-Saharan African nation of Tanzania faces a two-sided nitrogen problem: while there is not enough soil nitrogen to produce adequate food, excess nitrogen that escapes into the environment causes a cascade of ecological and human health problems. To identify, quantify, and contribute to solving these problems, this paper presents a nitrogen footprint tool for Tanzania. This nitrogen footprint tool is a concept originally designed for the United States of America (USA) and other developed countries. It uses personal resource consumption data to calculate a per-capita nitrogen footprint. The Tanzania N footprint tool is a version adapted to reflect the low-input, integrated agricultural system of Tanzania. This is reflected by calculating two sets of virtual N factors to describe N losses during food production: one for fertilized farms and one for unfertilized farms. Soil mining factors are also calculated for the first time to address the amount of N removed from the soil to produce food. The average per-capita nitrogen footprint of Tanzania is 10 kg N yr-1. 88% of this footprint is due to food consumption and production, while only 12% of the footprint is due to energy use. Although 91% of farms in Tanzania are unfertilized, the large contribution of fertilized farms to N losses causes unfertilized farms to make up just 83% of the food production N footprint. In a developing country like Tanzania, the main audiences for the N footprint tool are community leaders, planners, and developers who can impact decision-making and use the calculator to plan positive changes for nitrogen sustainability in the developing world.

Economic Tools for Managing Nitrogen in Coastal Watersheds ...

Science.gov (United States)

Watershed managers are interested in using economics to communicate the value of estuarine resources to the wider community, determine the most cost-effective means to reduce nitrogen pollution, and evaluate the benefits of taking action to improve coastal ecosystems. We spoke to coastal watershed managers who had commissioned economic studies and found that they were largely satisfied with the information and their ability to communicate the importance of coastal ecosystems. However, while managers were able to use these studies as communication tools, methods used in some studies were inconsistent with what some economists consider best practices. In addition, many watershed managers are grappling with how to implement nitrogen management activities in a way that is both cost-effective and achieves environmental goals, while maintaining public support. These and other issues led to this project. Our intent is to provide information to watershed managers and others interested in watershed management – such as National Estuary Programs, local governments, or nongovernmental organizations – on economic tools for managing nitrogen in coastal watersheds, and to economists and other analysts who are interested in assisting them in meeting their needs. Watershed management requires balancing scientific, political, and social issues to solve environmental problems. This document summarizes questions that watershed managers have about using economic analysis, and g

Nitrogen-fixing and uricolytic bacteria associated with the gut of Dendroctonus rhizophagus and Dendroctonus valens (Curculionidae: Scolytinae).

Science.gov (United States)

Morales-Jiménez, Jesús; Vera-Ponce de León, Arturo; García-Domínguez, Aidé; Martínez-Romero, Esperanza; Zúñiga, Gerardo; Hernández-Rodríguez, César

2013-07-01

The bark beetles of the genus Dendroctonus feed on phloem that is a nitrogen-limited source. Nitrogen fixation and nitrogen recycling may compensate or alleviate such a limitation, and beetle-associated bacteria capable of such processes were identified. Raoultella terrigena, a diazotrophic bacteria present in the gut of Dendroctonus rhizophagus and D. valens, exhibited high acetylene reduction activity in vitro with different carbon sources, and its nifH and nifD genes were sequenced. Bacteria able to recycle uric acid were Pseudomonas fluorescens DVL3A that used it as carbon and nitrogen source, Serratia proteomaculans 2A CDF and Rahnella aquatilis 6-DR that used uric acid as sole nitrogen source. Also, this is the first report about the uric acid content in whole eggs, larvae, and adults (male and female) samples of the red turpentine beetle (Dendroctonus valens). Our results suggest that the gut bacteria of these bark beetles could contribute to insect N balance.

Using a simple model for water and nitrogen transport in soil in the practical works of Horticulture

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A. Lidón

2017-08-01

Full Text Available Simulation models for the transport of water and nitrogen in the soil are useful tools for evaluating the consequences  of  different  crop  management  practices  without  waiting  until  the  end  of  the  crop  cycle.  Particularly,  simple compartmental models for the transport of water and nitrogen are based on the solution of mass balance equations for  the  water  and  a  system  of  ordinary  differential  equations  for  the  nitrogen  cycle.  In this work, these models are used to evaluate different possible scenarios of irrigation and nitrogen fertilization in a cauliflower crop, as a practical work for the students of Horticulture course. The results show that different irrigation and fertilization strategies lead to different results for the nitrate leaching, water drainage and nitrogen uptake.

Morphogenesis of Tanzania guinea grass under nitrogen doses and plant densities

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Thiago Gomes dos Santos Braz

2011-07-01

Full Text Available The objective of this work was to evaluate effects of nitrogen fertilization and plant density on morphogenesis of Tanzania guinea grass. It was used a random block design with 12 treatments and two replications in a 4 × 3 factorial arrangement, with four doses of nitrogen (N (without N application, 80, 160 or 320 kg/ha.year and three plant densities (9, 25 or 49 plants/m². Harvest was performed at 25 cm from the ground when the canopy intercepted 95% of the incident light. Rates of leaf appearance and pseudostem elongation were positively and linearly influenced by nitrogen, whereas phillochron and leaf life span were influenced linearly and negatively. Leaf elongation responded positively to two factors, whereas leaf senescence rate and number of live leaves were not influenced by the factors evaluated. Number of total, basal and aerial tillers were greater at the density of 9 plants/m² and at the nitrogen dose of 320 kg/ha.year. Nitrogen increases production of leaves and tillers in Tanzania guinea grass defoliated at 95% of light interception, but high density of plants reduces the number of tiller per bunch.

Nitrogen uptake and balance of the fertilizers urea, urea with urease inhibitor, and ammonium nitrate applied to spring wheat at stem elongation growth stage

International Nuclear Information System (INIS)

Matzel, W.; Lippold, H.; Heber, R.

1979-01-01

The use of urea containing 1% of diamido phosphoric acid phenyl ester, which is a urease inhibitor, for the top dressing of spring wheat on light soil allows the loss of nitrogen due to volatilization of ammonia from urea to be prevented. The urease inhibitor has no effect whatsoever upon the uptake of urea nitrogen by spring wheat. Even in those cases where the volatilization of ammonia is prevented, plants will take up 5 to 6% less nitrogen from urea than from ammonium nitrate. This is due primarily to the higher degree of immobilization of urea nitrogen in the soil. The volatilization of ammonia from urea applied to the surface of the soil was in the region of 25% when the soil surface was moist and 10% when the soil surface was dry, the percentages given above being related to the amount of fertilizer nitrogen applied to the soil. The plant uptake of fertilizer nitrogen applied as a second dose at stem elongation will be complete after two to three weeks or after six weeks under favourable or unfavourable conditions, respectively. Proceeding immediately after application of the fertilizer nitrogen are the processes resulting in both loss of nitrogen and its immobilization. The proportion of absorbed fertilizer nitrogen recovered in the grain will be the greater the later the nitrogen is incorporated into the plant. The use in pot experiments of labelled nitrogen fertilizers enables statistically significant differences in effects to be determined even in those cases in which the differences are only relatively small in degree. (author)

Ethanol induction of laccase depends on nitrogen conditions of Pycnoporus sanguineus

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Christian A. Hernández

2015-07-01

Conclusions: We suggest that laccase in P. sanguineus is regulated by a catabolic nitrogen repression mechanism; laccase activity is strongly inhibited by urea used as nitrogen source and it decreases when the amount of urea increases; contrarily, a synergic positive effect was observed between yeast extract and ethanol on laccase production.

Improvement of wine terroir management according to biogeochemical cycle of nitrogen in soil

Science.gov (United States)

Najat, Nassr; Aude, Langenfeld; Mohammed, Benbrahim; Lionel, Ley; Laurent, Deliere; Jean-Pascal, Goutouly; David, Lafond; Marie, Thiollet-Scholtus

2015-04-01

Good wine terroir production implies a well-balanced Biogeochemical Cycle of Nitrogen (BCN) at field level i.e. in soil and in plant. Nitrogen is very important for grape quality and soil sustainability. The mineralization of organic nitrogen is the main source of mineral nitrogen for the vine. This mineralization depends mainly on the soil microbial activity. This study is focused on the functional microbial populations implicated in the BCN, in particular nitrifying bacteria. An experimental network with 6 vine sites located in Atlantic coast (Loire valley and Bordeaux) and in North-East (Alsace) of France has been set up since 2012. These vine sites represent a diversity of environmental factors (i.e. soil and climate). The adopted approach is based on the measure of several indicators to assess nitrogen dynamic in soil, i.e. nitrogen mineralization, regarding microbial biomass and activity. Statistical analyses are performed to determine the relationship between biological indicator and nitrogen mineralisation regarding farmer's practices. The variability of the BCN indicators seems to be correlated to the physical and chemical parameters in the soil of the field. For all the sites, the bacterial biomass is correlated to the rate and kinetic of nitrogen in soil, however this bioindicator depend also on others parameters. Moreover, the functional bacterial diversity depends on the soil organic matter content. Differences in the bacterial biomass and kinetic of nitrogen mineralization are observed between the sites with clayey (Loire valley site) and sandy soils (Bordeaux site). In some tested vine systems, effects on bacterial activity and nitrogen dynamic are also observed depending on the farmer's practices: soil tillage, reduction of inputs, i.e. pesticides and fertilizers, and soil cover management between rows. The BCN indicators seem to be strong to assess the dynamics of the nitrogen in various sites underline the functional diversity of the soils. These

Positive carotenoid balance correlates with greater reproductive performance in a wild bird.

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Rebecca J Safran

Full Text Available BACKGROUND: Carotenoids can confer somatic and reproductive benefits, but most evidence is from captive animal experimentation or single time-point sampling. Another perhaps more informative means by which to assess physiological contributions to animal performance is by tracking an individual's ability to increase or sustain carotenoids or other health-related molecules over time, as these are likely to be temporally variable. METHODOLOGY/PRINCIPAL FINDINGS: In a field study of North American barn swallows (Hirundo rustica erythrogaster, we analyzed within-individual changes in carotenoid concentrations by repeatedly sampling the carotenoid profiles of individuals over the course of the breeding season. Our results demonstrate that carotenoid concentrations of individuals are temporally dynamic and that season-long balance of these molecules, rather than single time-point samples, predict reproductive performance. This was true even when controlling for two important variables associated with reproductive outcomes: (1 timing of breeding and (2 sexually selected plumage coloration, which is itself positively correlated with and concomitantly changes with circulating carotenoid concentrations. CONCLUSIONS/SIGNIFICANCE: While reproduction itself is purported to impose health stress on organisms, these data suggest that free-ranging, high-quality individuals can mitigate such costs, by one or several genetic, environmental (diet, or physiological mechanisms. Moreover, the temporal variations in both health-linked physiological measures and morphological traits we uncover here merit further examination in other species, especially when goals include the estimation of signal information content or the costs of trait expression.

Nitrogen losses from dairy manure estimated through nitrogen mass balance and chemical markers

Science.gov (United States)

Hristov, Alexander N.; Zaman, S.; Vander Pol, M.; Ndegwa, P.; Campbell, L.; Silva, S.

2009-01-01

Ammonia is an important air and water pollutant, but the spatial variation in its concentrations presents technical difficulties in accurate determination of ammonia emissions from animal feeding operations. The objectives of this study were to investigate the relationship between ammonia volatilization and ??15N of dairy manure and the feasibility of estimating ammonia losses from a dairy facility using chemical markers. In Exp. 1, the N/P ratio in manure decreased by 30% in 14 d as cumulative ammonia losses increased exponentially. Delta 15N of manure increased throughout the course of the experiment and ??15N of emitted ammonia increased (p < 0.001) quadratically from -31??? to -15 ???. The relationship between cumulative ammonia losses and ??15N of manure was highly significant (p < 0.001; r2 = 0.76). In Exp. 2, using a mass balance approach, approximately half of the N excreted by dairy cows (Bos taurus) could not be accounted for in 24 h. Using N/P and N/K ratios in fresh and 24-h manure, an estimated 0.55 and 0.34 (respectively) of the N excreted with feces and urine could not be accounted for. This study demonstrated that chemical markers (P, K) can be successfully used to estimate ammonia losses from cattle manure. The relationship between manure ??15N and cumulative ammonia loss may also be useful for estimating ammonia losses. Although promising, the latter approach needs to be further studied and verified in various experimental conditions and in the field. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Precision analysis of 15N-labelled samples with the emission spectrometer NOI-5 for nitrogen balance in field trials

International Nuclear Information System (INIS)

Lippold, H.

1984-01-01

A technique was adapted for the preparation of samples with 15 N to be analyzed with the emission spectrometer NOI-5. This technique is based on methods of analyzing 15 N labelled gas samples in denitrification experiments. Nitrogen released from ammonium compounds by using hypobromite is injected into a repeatedly usable gaseous discharge tube where it is freed from water traces by means of the molecular sieve 5A. The described procedure of activating the molecular sieve allows to record spectra of reproducible quality thus promising an accuracy of analysis of +- 0.003 at% in the range of natural isotope frequency and the possibility of soil nitrogen analysis in field trials with fertilizers of low nitrogen content (3 to 6.5 at%; corresponding with 0.055 to 0.14% N/sub t/ of soils) without being dependent on mass spectrometers. (author)

Relationship between Balanced Fertilization and Healthy Agricultural Products (A Review

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M.J. Malakouti

2011-01-01

Full Text Available Based on World Health Organization (WHO report, our society’s health ranks 123 among 192 countries. Unfortunately, this ranking position is very low and its main reason is malnutrition due to imbalanced fertilization. Although more than 85% of Iranian people are not hungry, about 90% of them are suffering from cell hunger, because agricultural authorities and hence producers do not pay attention to food security. According to the latest information, about 86.5% of applied fertilizers in our country appertain to urea and triple super phosphate. In fact, this is an alarming issue in respect to the production of healthy agricultural products and it remains a threat to food security. At present, a total subsidy of more than 7,000 billion rials is paid for nitrogen (N and phosphate (P fertilizers. Whereas, it should be considered that, firstly, the efficiency of these fertilizers, due to different reasons such as mismanagement and existing subsidy level, is low and, secondly, the overuse of these fertilizers causes the accumulation of nitrate (NO3 and cadmium (Cd in agricultural products. Furthermore, according to the law of minimum, the overdosed fertilizers do not have any special positive effect on sustainable production and society’s health. Paying for such high-cost subsidy just for N and P-fertilizers has caused farmers to overuse and waste these fertilizers in the country and moreover not having any tendency to apply biologic, organic and micronutrient fertilizers. Whereas, the application of these fertilizers, beside their adaptability with the environment, has a very positive effect on the human health. Therefore, at this time scientific management of production and application of all kinds of fertilizers is inevitable. In this case, by improving the quality of all types of fertilizers, and following the principle of balanced fertilization, besides achieving the desired yield increase, the quality of agricultural products will be

Using Balanced Time Perspective to Explain Well-Being and Planning in Retirement

Science.gov (United States)

Mooney, Anna; Earl, Joanne K.; Mooney, Carl H.; Bateman, Hazel

2017-01-01

The notion of whether people focus on the past, present or future, and how it shapes their behavior is known as Time Perspective. Fundamental to the work of two of its earliest proponents, Zimbardo and Boyd (2008), was the concept of balanced time perspective and its relationship to wellness. A person with balanced time perspective can be expected to have a flexible temporal focus of mostly positive orientations (past-positive, present-hedonistic, and future) and much less negative orientations (past-negative and present-fatalistic). This study measured deviation from balanced time perspective (DBTP: Zhang et al., 2013) in a sample of 243 mature adults aged 45 to 91 years and explored relationships to Retirement Planning, Depression, Anxiety, Stress, Positive Mood, and Negative Mood. Results indicate that DBTP accounts for unexplained variance in the outcome measures even after controlling for demographic variables. DBTP was negatively related to Retirement Planning and Positive Mood and positively related to Depression, Anxiety, Stress, and Negative Mood. Theoretical and practical implications regarding balanced time perspective are discussed. PMID:29081757

Using Balanced Time Perspective to Explain Well-Being and Planning in Retirement.

Science.gov (United States)

Mooney, Anna; Earl, Joanne K; Mooney, Carl H; Bateman, Hazel

2017-01-01

The notion of whether people focus on the past, present or future, and how it shapes their behavior is known as Time Perspective. Fundamental to the work of two of its earliest proponents, Zimbardo and Boyd (2008), was the concept of balanced time perspective and its relationship to wellness. A person with balanced time perspective can be expected to have a flexible temporal focus of mostly positive orientations (past-positive, present-hedonistic, and future) and much less negative orientations (past-negative and present-fatalistic). This study measured deviation from balanced time perspective (DBTP: Zhang et al., 2013) in a sample of 243 mature adults aged 45 to 91 years and explored relationships to Retirement Planning, Depression, Anxiety, Stress, Positive Mood, and Negative Mood. Results indicate that DBTP accounts for unexplained variance in the outcome measures even after controlling for demographic variables. DBTP was negatively related to Retirement Planning and Positive Mood and positively related to Depression, Anxiety, Stress, and Negative Mood. Theoretical and practical implications regarding balanced time perspective are discussed.

Using Balanced Time Perspective to Explain Well-Being and Planning in Retirement

Directory of Open Access Journals (Sweden)

Anna Mooney

2017-10-01

Full Text Available The notion of whether people focus on the past, present or future, and how it shapes their behavior is known as Time Perspective. Fundamental to the work of two of its earliest proponents, Zimbardo and Boyd (2008, was the concept of balanced time perspective and its relationship to wellness. A person with balanced time perspective can be expected to have a flexible temporal focus of mostly positive orientations (past-positive, present-hedonistic, and future and much less negative orientations (past-negative and present-fatalistic. This study measured deviation from balanced time perspective (DBTP: Zhang et al., 2013 in a sample of 243 mature adults aged 45 to 91 years and explored relationships to Retirement Planning, Depression, Anxiety, Stress, Positive Mood, and Negative Mood. Results indicate that DBTP accounts for unexplained variance in the outcome measures even after controlling for demographic variables. DBTP was negatively related to Retirement Planning and Positive Mood and positively related to Depression, Anxiety, Stress, and Negative Mood. Theoretical and practical implications regarding balanced time perspective are discussed.

Efficiency of Different Nitrogen Forms in Buckwheat (Fagopyrum esculentum Moench

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Burhan Kara

2016-06-01

Full Text Available The research was carried out with aim to determination the efficient of nitrogen forms (ammonium sulfate, ammonium nitrate and urea on nitrogen use efficient for buckwheat in Isparta during 2014 and 2015 years. All the examined characteristics were determined higher values in applied nitrogen forms according to non-nitrogen parcel. In compared to nitrogen forms, the highest grain yield (1456 and 1325 kg ha-1, biological yield (4873 and 4512 kg ha-1, 1000 grain weight (24.9 and 24.8 g, agronomic efficient (24.96% and 24.25%, recycling efficient (0.24% and 0.22% and utilization efficient (0.25% and 0.18% were obtained from ammonium sulfate, the highest protein content (11.37% and 12.44% and agro-physiological efficient (0.27% and 0.24% from ammonium nitrate in both years. Among the nitrogen forms weren’t significant differently in physiological efficient in both years, recycling and utilization efficient in the first year. The mineral nutrient content varied according to nitrogen forms. Generally, ammonium sulfate was positive effect to yield and some quality parameters.

Ways to improve conceptual aspects of balancing the budget

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Dodon Svetlana

2013-02-01

Full Text Available The aim of the present article is to analyze the various concepts, techniques and procedures applied in different periods by different countries in order to balance state budget. There are analyzed positive parts and deficiencies at legislative level of different concepts concerning budgetary balance and as a result are developed a series of measures that aim to balance the budget of Moldova

Immediate effect of subliminal priming with positive reward stimuli on standing balance in healthy individuals

OpenAIRE

Aoyama, Yasuhiro; Uchida, Hiroyuki; Sugi, Yasuyuki; Kawakami, Akinobu; Fujii, Miki; Kiso, Kanae; Kono, Ryota; Takebayashi, Takashi; Hirao, Kazuki

2017-01-01

Abstract Background: Information received subconsciously can influence exercise performance; however, it remains unclear whether subliminal or supraliminal reward is more effective in improving standing balance ability when priming stimuli are subconsciously delivered. The present study aimed to compare the effects of subliminal priming-plus-subliminal reward stimuli (experimental) with subliminal priming-plus-supraliminal reward stimuli (control) on standing balance ability. Methods: This wa...

Balanço do nitrogênio e fósforo em solo com cultivo orgânico de hortaliças após a incorporação de biomassa de guandu Nitrogen and phosphorus balance in soil with organic cultivation of legumes after incorporation of pigeonpea biomass

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Sandra Maria Campos Alves

2004-11-01

Full Text Available Os objetivos deste trabalho foram avaliar os efeitos de faixas de guandu (Cajanus cajan e da incorporação da biomassa proveniente de sua poda na fertilidade do solo e na produtividade de três hortaliças sob cultivo orgânico. O delineamento usado foi de blocos casualizados completos em esquema de parcelas subsubdivididas com três repetições. As produtividades de beterraba, cenoura e feijão-de-vagem não foram afetadas pelos tratamentos. Nas parcelas onde não houve incorporação da biomassa de guandu, o balanço de nitrogênio no sistema foi negativo, ao passo que com a incorporação, esse balanço foi positivo. Embora tenha ocorrido balanço positivo para o fósforo nas parcelas sem a incorporação de biomassa de guandu, houve um aumento significativo na absorção desse elemento pelas hortaliças quando o material foi incorporado. O sistema de cultivo em aléias de guandu pode representar uma prática vantajosa para os produtores orgânicos, por contribuir na manutenção da fertilidade do solo.The objectives of this study were to evaluate the efficiency of pigeonpea (Cajanus cajan biomass incorporation to the soil as well as the effect of presence or absence of pigeonpea hedgerows on soil fertility and productivity of three vegetables, beet, carrot and dwarf green bean. Samples were randomly taken in a block design with three replications for each crop. In the field, no other fertilization treatment was applied. In plots without biomass incorporation, nitrogen showed negative balance, whereas in the field with biomass incorporation a high positive N-balance was found. Concerning phosphorus, positive balances were determined in plots without biomass incorporation, however, the uptake of P increased significantly after biomass incorporation in all crops used. The results indicate that pigeonpea alley cropping system may represent an advantageous option for organic farmers to maintain or to improve soil fertility.

Effect of molasses or cornmeal on milk production and nitrogen utilization of grazing organic dairy cows

Science.gov (United States)

Pasture is rich in soluble nitrogen (N) which is rapidly converted to ammonia in the rumen reducing N utilization in lactating dairy cows. Sucrose is more quickly degraded in the rumen than starch, suggesting that feeding molasses (MOL) to balance the supplies of energy and rumen degradable protein...

Nitrogen limitation and life history adaptation in the grasshopper "Omocestus viridulus"

OpenAIRE

Berner, Daniel

2005-01-01

The role of plant-mediated constraints to herbivore populations in terrestrial ecosystems remains relatively poorly understood. One aim of this study was therefore to explore the effects of low host plant nitrogen (N) content on herbivore performance and feeding behaviour, and thereby to evaluate the utility of the N limitation and nutrient balance concepts. The grass-feeding grasshopper Omocestus viridulus (Orthoptera: Acrididae) provided a well-suited model system as the species exhibits hi...

The use of Total Body In Vivo Neutron Activation Analysis (TBIVNAA) in balance studies in rodents

International Nuclear Information System (INIS)

Smith, D.A.; Lindsay, R.L.; Anderson, J.

1976-01-01

In the investigation of animals subject to alteration in diet or other metabolic experiments, the measurements of change in body calcium, phosphorus, sodium and nitrogen are of considerable interest. However, conventional balance studies are tedious and subject to both random and cumulative error, necessitating as they do accurate estimates of dietary intake and faecal and urinary output. The object of the present study was to determine the usefulness of total body in vivo neutron activation analysis, used at the beginning and end of the experimental period, as an alternative to conventional balance techniques. (orig.) [de

Total mixed ration in exercising horse: digestibility and nitrogen metabolism

Directory of Open Access Journals (Sweden)

L. Magni

2010-04-01

Full Text Available The aim of this study was to evaluate the apparent digestibility of a total mixed ration (TMR versus a traditional mixed hay/cereals diet. Four adult trained Standardbred geldings – BW = 478±37 kg - were used. The two diets consisted of 20 kg of a commercial TMR - corn silage, alfalfa hay, wet brewers’ grain, oat, apple pomace, molasses cane, soybean oil and mineral/vitamin supplement - (Diet 1 or 7 kg of meadow hay and 4.5 kg of cereal-mix - corn, oat, barley and protein/mineral/vitamin supplement - (Diet 2. The trial was conducted according to a Latin Square design (2x2. After an adaptation period of four weeks, total faeces and urine were collected for 6 days. Both feed and faeces samples were analysed for DM, OM, CP, EE, CF, NDF, ADF, cellulose, hemicellulose, ADL and GE. Data were analysed by ANOVA. The apparent digestibility and nitrogen balance of the two diets were compared. DM, OM, CP and GE apparent digestibility were significantly different between the diets, with higher values for unifeed diet than traditional diet. Energy requirement was satisfied by both diets (96.54 vs 95.55 MJ. Nitrogen balance showed negative values in both diets (- 61.67 vs - 9.05, but the hay/cereals supplemented diet showed the best protein utilisation.

Milk production, nutrient digestibility and nitrogen balance in lactating cows fed total mixed ration silages containing steam-flaked brown rice as substitute for steam-flaked corn, and wet food by-products.

Science.gov (United States)

Miyaji, Makoto; Matsuyama, Hiroki; Hosoda, Kenji; Nonaka, Kazuhisa

2013-06-01

The objective of this study was to evaluate the effect of substituting brown rice grain for corn grain in total mixed ration (TMR) silage containing food by-products on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows. Six multiparous Holstein cows were used in a crossover design with two dietary treatments: a diet containing 30.9% steam-flaked corn (corn TMR) or 30.9% steam-flaked brown rice (rice TMR) with wet soybean curd residue and wet soy sauce cake. Dietary treatment did not affect the dry matter intake, milk yield and compositions in dairy cows. The dry matter and starch digestibility were higher, and the neutral detergent fiber digestibility was lower for rice TMR than for corn TMR. The urinary nitrogen (N) excretion as a proportion of the N intake was lower for rice TMR than for corn TMR with no dietary effect on N secretion in milk and fecal N excretion. These results indicated that the replacement of corn with brown rice in TMR silage relatively reduced urinary N loss without adverse effects on feed intake and milk production, when food by-products such as soybean curd residue were included in the TMR silage as dietary crude protein sources. © 2013 Japanese Society of Animal Science.

How Does Recycling of Livestock Manure in Agroecosystems Affect Crop Productivity, Reactive Nitrogen Losses, and Soil Carbon Balance?

Science.gov (United States)

Xia, Longlong; Lam, Shu Kee; Yan, Xiaoyuan; Chen, Deli

2017-07-05

Recycling of livestock manure in agroecosystems to partially substitute synthetic fertilizer nitrogen (N) input is recommended to alleviate the environmental degradation associated with synthetic N fertilization, which may also affect food security and soil greenhouse gas (GHG) emissions. However, how substituting livestock manure for synthetic N fertilizer affects crop productivity (crop yield; crop N uptake; N use efficiency), reactive N (Nr) losses (ammonia (NH 3 ) emission, N leaching and runoff), GHG (methane, CH 4 ; and nitrous oxide, N 2 O; carbon dioxide) emissions and soil organic carbon (SOC) sequestration in agroecosystems is not well understood. We conducted a global meta-analysis of 141 studies and found that substituting livestock manure for synthetic N fertilizer (with equivalent N rate) significantly increased crop yield by 4.4% and significantly decreased Nr losses via NH 3 emission by 26.8%, N leaching by 28.9% and N runoff by 26.2%. Moreover, annual SOC sequestration was significantly increased by 699.6 and 401.4 kg C ha -1 yr -1 in upland and paddy fields, respectively; CH 4 emission from paddy field was significantly increased by 41.2%, but no significant change of that was observed from upland field; N 2 O emission was not significantly affected by manure substitution in upland or paddy fields. In terms of net soil carbon balance, substituting manure for fertilizer increased carbon sink in upland field, but increased carbon source in paddy field. These results suggest that recycling of livestock manure in agroecosystems improves crop productivity, reduces Nr pollution and increases SOC storage. To attenuate the enhanced carbon source in paddy field, appropriate livestock manure management practices should be adopted.

Keeping the heart in balance: the functional interactions of myoglobin with nitrogen oxides

DEFF Research Database (Denmark)

Flögel, Ulrich; Fago, Angela; Rassaf, Tienush

2010-01-01

in the heart. By a dynamic cycle, in which a decrease in tissue O2 tension drives the conversion of Mb from being a NO scavenger under normoxia to a NO producer during hypoxia, mitochondrial respiration is reversibly adapted to the intracellular O2 tension. Therefore, Mb may act as an important O2 sensor...... through which NO can regulate muscle energetics and function. As Mb is widespread throughout the fauna, the diverse oxygen-dependent interactions between Mb and nitrogen oxides may not only be of relevance for mammals but also for other vertebrates as evidenced by comparable phenotypes of ‘artificial...

Hormone Replacement and Strength Training Positively Influence Balance During Gait in Post-Menopausal Females: A Pilot Study

Science.gov (United States)

Perry, Stephen D.; Bombardier, Eric; Radtke, Alison; Tiidus, Peter M.

2005-01-01

This study examined the effects of hormone replacement combined with strength training on improving dynamic balance control in post-menopausal women. Thirty one participating post-menopausal women were divided into three groups (hormone replacement (HR), non-hormone replacement (NR) and control (CR) group). HR and NR groups were tested for muscle strength and balance control during gait, prior to training and following a six week lower body strength training program. Quadriceps muscle strength was evaluated as isokinetic peak torque (60°·sec-1) using a CYBEX NORM and balance control was evaluated by center of mass - base of support relationships and ground reaction forces during gait perturbations. Only the HR group showed significantly (p < 0.05) improved balance control during the initial phase of unexpected gait termination and single stance periods while walking across uneven terrain following training. The strength gains in the HR group tended to be greater than in the NR group over the six week training program, although neither group showed statistically significant increases. The CR group showed no significant differences between testing times. HR in post-menopausal females may enhance dynamic balance control when combined with a strength training program, even if no statistically significant gains in strength are achieved. Key Points This study provides evidence that even a short modest strength training program can enhance dynamic balance control in older adult females taking hormone replacement. If potential benefits of hormone replacement therapy extend to enhancing muscle strength then this would be important in designing optimal interventions for both strength and balance for this cohort. Future work should explore the influence of hormone replacement therapy on other dynamic balance or functional tasks. PMID:24501551

Working part-time: achieving a successful 'work-life' balance?

Science.gov (United States)

Warren, Tracey

2004-03-01

The role of part-time employment in the balancing of women's employment and family lives has generated an immense literature. Using data on women working part-time and full-time in different level occupations in the British Household Panel Survey, this paper argues that it is now vital to move these balancing debates on from their location within work-family rhetoric and to re-position the study of women's working time in broader work-life discussions. Work-family debates tend to neglect a number of key domains that women balance in their lives, in addition to family and employment, including their financial security and their leisure. The paper shows that examining the financial situations and the leisure lives of female part-timers in lower level jobs reveals a less positive picture of their 'life balancing' than is portrayed in much work-family literature. Instead, they emerged as the least financially secure employees and, linked to this, less satisfied with their social lives too. It is concluded that since the work-life system is multi- and not just two-dimensional, it is important to examine how all life domains interrelate with each other. In this way, we would be in a better position to begin to assess all the benefits and disadvantages associated with working part-time and with other work-life balancing strategies.

Mass balance of nutrients during the filling phase of two reservoirs of Sistema Produtor Alto Tietê (SPAT - doi: 10.4025/actascibiolsci.v33i1.7313 Mass balance of nutrients during the filling phase of two reservoirs of Sistema Produtor Alto Tietê (SPAT - doi: 10.4025/actascibiolsci.v33i1.7313

Directory of Open Access Journals (Sweden)

Adalberto José Monteiro Junior

2011-02-01

Full Text Available Paraitinga and Biritiba reservoirs are part of Sistema Produtor Alto Tietê and they play an important role at the public water supply. The purpose of this study is to understand the mass balance of nitrogen and phosphorus that can influence the eutrophication process in reservoirs during the filling phase, and provide information for the implementation of mechanisms to manage water quality. Water samples were collected from August 2005 until May 2006. Concentrations of total phosphorus (PT and total nitrogen (NT were measured and the mass balance and loads were estimated. Paraitinga reservoir presented retention of NT and PT during the dry season and export during the rainy season; whilst at Biritiba reservoir we evidenced retention of NT and PT for both dry and rainy seasons. The annual balance demonstrated that during the reservoirs filling process, the systems retain NT and PT. The retention of nutrients into the system indicates that the environments have been modified leading to eutrophication and its consequences, and that it is necessary to outline strategies in order to mitigate the problem and suggest implementation of techniques to reduce the diffuse load.Paraitinga and Biritiba reservoirs are part of Sistema Produtor Alto Tiet�� and they play an important role at the public water supply. The purpose of this study is to understand the mass balance of nitrogen and phosphorus that can influence the eutrophication process in reservoirs during the filling phase, and provide information for the implementation of mechanisms to manage water quality. Water samples were collected from August 2005 until May 2006. Concentrations of total phosphorus (PT and total nitrogen (NT were measured and the mass balance and loads were estimated. Paraitinga reservoir presented retention of NT and PT during the dry season and export during the rainy season; whilst at Biritiba reservoir we evidenced retention of NT and PT for both dry and rainy seasons

On Energy Balance and Production Costs in Tubular and Flat Panel Photobioreactors

NARCIS (Netherlands)

Norsker, N.H.; Barbosa, M.J.; Vermue, M.H.; Wijffels, R.H.

2012-01-01

Reducing mixing in both flat panel and tubular photobioreactors can result in a positive net energy balance with state-of-the-art technology and Dutch weather conditions. In the tubular photobioreactor, the net energy balance becomes positive at velocities <0.3 ms-1, at which point the biomass

DETERMINATION OF HEAT TRANSFER COEFFICIENTS FOR FRENCH PLASTIC SEMEN STRAW SUSPENDED IN STATIC NITROGEN VAPOR OVER LIQUID NITROGEN.

Science.gov (United States)

Santo, M V; Sansinena, M; Chirife, J; Zaritzky, N

2015-01-01

The use of mathematical models describing heat transfer during the freezing process is useful for the improvement of cryopreservation protocols. A widespread practice for cryopreservation of spermatozoa of domestic animal species consists of suspending plastic straws in nitrogen vapor before plunging into liquid nitrogen. Knowledge of surface heat transfer coefficient (h) is mandatory for computational modelling; however, h values for nitrogen vapor are not available. In the present study, surface heat transfer coefficients for plastic French straws immersed in nitrogen vapor over liquid nitrogen was determined; vertical and horizontal positions were considered. Heat transfer coefficients were determined from the measurement of time-temperature curves and from numerical solution of heat transfer partial differential equation under transient conditions using finite elements. The h values experimentally obtained for horizontal and vertically placed straws were compared to those calculated using correlations based on the Nusselt number for natural convection. For horizontal straws the average obtained value was h=12.5 ± 1.2 W m(2) K and in the case of vertical straws h=16 ± 2.48 W m(2) K. The numerical simulation validated against experimental measurements, combined with accurate h values provides a reliable tool for the prediction of freezing curves of semen-filled straws immersed in nitrogen vapor. The present study contributes to the understanding of the cryopreservation techniques for sperm freezing based on engineering concepts, improving the cooling protocols and the manipulation of the straws.

Influence of slow-release urea on nitrogen balance and portal-drained visceral nutrient flux in beef steers

DEFF Research Database (Denmark)

Taylor-Edwards, C C; Elam, N A; Kitts, S E

2009-01-01

Two experiments were conducted to evaluate the effects of slow-release urea (SRU) versus feed-grade urea on portal-drained visceral (PDV) nutrient flux, nutrient digestibility, and total N balance in beef steers.......Two experiments were conducted to evaluate the effects of slow-release urea (SRU) versus feed-grade urea on portal-drained visceral (PDV) nutrient flux, nutrient digestibility, and total N balance in beef steers....

Peak torque and muscle balance in the knees of young U-15 and U-17 soccer athletes playing various tactical positions.

Science.gov (United States)

Chiamonti Bona, Cleiton; Tourinho Filho, Hugo; Izquierdo, Mikel; Pires Ferraz, Ricardo M; Marques, Mário C

2017-01-01

Soccer is a sport that is practiced worldwide and has been investigated in its various aspects, particularly muscle strength, which is an essential motor skill for sports performance. The objective of this study was to investigate the peak torque and muscle balance on the knee extensor and flexor of young soccer players in the tactical positions of goalkeeper, defender, full back, midfielder, defensive midfielder and striker, as well as to determine which field position has the highest peak torque. Forty-nine male players were recruited and divided into two categories during the preparatory period of the season: the Under-15 (U-15) group (N.=23, mean age 14.7±0.5 years, body mass 58.2±10.5 kg, body height 168.5±7.6 cm), and the Under-17 (U-17) group (N.=26, mean age 16.8±0.4 years, body mass 69.2±7.9 kg, body height 176.2±6.6 cm). The U-17 athletes presented a higher peak torque in all the movements of flexion and extension in the two angular velocities (i.e. 60°/s and 300°/s), but only the dominant knee extensor at 300°/s was significantly different between the two categories as well as the percentage change in peak torque compared between U-15 and U-17 was always above 20%. The peak torque variation in the U-17 category (i.e. mostly above 20%) highlights a higher peak torque compared to U-15 athletes. The muscular deficit of the two categories presented a low average of 10-15%, indicating a good muscle balance between knee extensors and flexors. Finally, goalkeepers and defenders achieved the highest peak torque amongst the field positions.

Triple vessel coronary artery disease presenting as a markedly positive stress electrocardiographic test and a negative SPECT-TL scintigram: a case of balanced Ischemia

Directory of Open Access Journals (Sweden)

Eyal Herzog

2011-09-01

Full Text Available The presence of false negative nuclear stress test in the settings of positive electrocardiographic changes is a very unusual phenomenon and is usually secondary to balanced ischemia of the myocardial segments evaluated by SPECT-TL. We present a case of an 81- year old post-menopausal female who presented to her primary care physician for evaluation of a 6-week dyspnea on exertion and was referred to our institution for exercise stress test with Thallium SPECT with the objective of ruling out coronary artery disease and identifying possible areas of myocardial ischemia. The resting electrocardiogram was unremarkable and stress test evaluation was made. The patient was admitted to the cardiac care unit and coronary artery bypass grafting was successfully performed. The presence of false negative nuclear stress test in the settings of positive electrocardiographic changes is a very unusual phenomenon and is usually secondary to balanced ischemia of the myocardial segments evaluated by SPECT-TL. Patients undergoing stress tests with these characteristics should undergo careful evaluation and a high level of suspicion should be adopted for further diagnostic assessment of coronary artery disease.

Identifying organic nitrogen compounds in Rocky Mountain National Park aerosols

Science.gov (United States)

Beem, K. B.; Desyaterik, Y.; Ozel, M. Z.; Hamilton, J. F.; Collett, J. L.

2010-12-01

Nitrogen deposition is an important issue in Rocky Mountain National Park (RMNP). While inorganic nitrogen contributions to the ecosystems in this area have been studied, the sources of organic nitrogen are still largely unknown. To better understand the potential sources of organic nitrogen, filter samples were collected and analyzed for organic nitrogen species. Samples were collected in RMNP using a Thermo Fisher Scientific TSP (total suspended particulate) high-volume sampler with a PM2.5 impactor plate from April - November of 2008. The samples presented the opportunity to compare two different methods for identification of individual organic nitrogen species. The first type of analysis was performed with a comprehensive two dimensional gas chromatography (GCxGC) system using a nitrogen chemiluminescence detector (NCD). The filter samples were spiked with propanil in dichloromethane to use as an internal standard and were then extracted in water followed by solid phase extraction. The GCxGC system was comprised of a volatility based separation (DB5 column) followed by a polarity based separation (RXI-17 column). A NCD was used to specifically detect nitrogen compounds and remove the complex background matrix. Individual standards were used to identify peaks by comparing retention times. This method has the added benefit of an equimolar response for nitrogen so only a single calibration is needed for all species. In the second analysis, a portion of the same filter samples were extracted in DI water and analyzed with liquid chromatography coupled with mass spectroscopy (LC/MS). The separation was performed using a C18 column and a water-methanol gradient elution. Electrospray ionization into a time of flight mass spectrometer was used for detection. High accuracy mass measurement allowed unambiguous assignments of elemental composition of resulting ions. Positive and negative polarities were used since amines tend to show up in positive mode and nitrates in