Isotopic studies of the nitrogen balance in a cracking clay. I. Recovery of added nitrogen from soil and wheat in the glasshouse and gas lysimeter

Soil Research ◽  
1975 ◽  
Vol 13 (1) ◽  
pp. 43 ◽  
Author(s):  
ET Craswell ◽  
AE Martin
Keyword(s):  
Stable Isotope ◽  
Nitrogen Balance ◽  
Limit Of Detection ◽  
Complete Recovery ◽  
Nitrogen Fertilizers ◽  
Common Finding ◽  
Plant Analysis ◽  
Isotopic Studies ◽  
Fate Of Nitrogen ◽  
The Common

The stable isotope 15N 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 % moisture (pF 2) into pots, added nitrate was almost completely recovered (mean, 98.8 � 2.3 %) by soil and plant analysis. This experiment was repeated using 15N-labelled ammonium as well as nitrate; mean recoveries at 15 weeks were 96.8 and 97% respectively (� 2.2% at P < 0.05). A series of pots with soil wetter than pF 2 (at 63% moisture) was also included in an attempt to favour denitrification. Again, virtually complete recovery of added 15N was measured, 97 and 96.8% at 56 and 63% moisture respectively. Fallow and planted systems were then studied in a gas lysimeter. During experiments lasting up to 14 weeks, gaseous losses as 15N-labelled denitrification products were less than the equivalent of 0.2 �g 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%), small (0.16%) 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.

Isotopic studies of the nitrogen balance in a cracking clay. II. Recovery of nitrate 15N added to columns of packed soil and microplots growing wheat in the field

Soil Research ◽  
1975 ◽  
Vol 13 (1) ◽  
pp. 53 ◽  
Author(s):  
ET Craswell ◽  
AE Martin
Keyword(s):  
Nitrogen Balance ◽  
Clay Soil ◽  
Heavy Rain ◽  
Plant Analysis ◽  
The Third ◽  
Isotopic Studies ◽  
Heavy Clay ◽  
Nitrate Fertilizer ◽  
Series Of Experiments

In a series of experiments, 15N-labelled nitrate fertilizer was used to study the nitrogen balance of a heavy clay soil. Two of the experiments employed 60-cm deep, 16-cm diameter columns of packed soil. In the first, no added 15N was lost until heavy rain saturated the soil in the undrained columns. Subsequently, fallow and planted columns lost 25% of the 15N added. While denitrification appeared primarily responsible for these losses, some of the 15N may have been lost by weathering of the plants during senescence. This experiment was repeated with precautions to prevent excessive rain saturating the soil. After 16 weeks, only 6 � 4.5% of the added 15N was not accounted for by soil and plant analysis. In the third experiment, I5N was added to 16-cm diameter confined microplots in situ. The microplots were fallow and were confined by 60-cm deep plastic pipe. After 16 weeks, during which 190 mm of rain fell, 97.7 � 2.4% of the added 15N was recovered.

Isotopic studies of the nitrogen balance in a cracking clay. IV. Fate of the three nitrogen fertilizers in fallow soil in the field

Soil Research ◽  
1979 ◽  
Vol 17 (2) ◽  
pp. 317 ◽  
Author(s):  
ET Craswell
Keyword(s):  
Ammonium Sulfate ◽  
Nitrogen Balance ◽  
Calcium Nitrate ◽  
Nitrogen Immobilization ◽  
The Other ◽  
Nitrogen Fertilizers ◽  
Field Site ◽  
Loss Mechanism ◽  
Isotopic Studies ◽  
Fallow Soil

Urea, ammonium sulfate and calcium nitrate, labelled with 15N, were added to 30-cm diameter microplots at a cracking clay field site. Sorghum stubble was applied to one series of microplots, while another series was stubble-free. The plots were kept fallow for 14 weeks after which the loss, movement and immobilization of the 15N added in the fertilizers was measured. Losses totalled 9, 23 and 26% of the urea, ammonium sulfate and calcium nitrate respectively. Denitrification, which occurred during the sixth and seventh weeks of the experiment when the soil was waterlogged, was presumed to be the loss mechanism; the differences in rate of loss would then be related to the rate of nitrification of the urea and ammonium fertilizers. Adding sorghum stubble did not influence the rate of loss but caused net immobilization of an extra 5 % of the added nitrogen; immobilization was 11, 11 and 7% in the microplots receiving urea, ammonium sulfate and calcium nitrate respectively. The 155 mm of rain received during the 14 weeks leached 20% of the added nitrate and only 10% of the other fertilizers below 30 cm.

scholarly journals Multi-attribute Decision-making is Best Characterized by an Attribute-Wise Reinforcement Learning Model

2017 ◽  
Author(s):  
Shaoming Wang ◽  
Bob Rehder
Keyword(s):  
Computational Models ◽  
Theoretical Models ◽  
Decision Makers ◽  
Common Finding ◽  
Cue Competition ◽  
Recency Effects ◽  
Multiple Attribute ◽  
Multi Attribute Decision Making ◽  
The Common ◽  
Alternative Choice

AbstractChoice alternatives often consist of multiple attributes that vary in how successfully they predict reward. Some standard theoretical models assert that decision makers evaluate choices either by weighting those attribute optimally in light of previous experience (so-called rational models), or adopting heuristics that use attributes suboptimally but in a manner that yields reasonable performance at minimal cost (e.g., the take-the-best heuristic). However, these models ignore both the possibility that decision makers might learn to associate reward with whole stimuli (a particular combination of attributes) rather than individual attributes and the common finding that decisions can be overly influenced by recent experiences and exhibit cue competition effects. Participants completed a two-alternative choice task where each stimulus consisted of three binary attributes that were predictive of reward, albeit with different degrees of reliability. Their choices revealed that, rather than using only the “best” attribute, they made use of all attributes but in manner that reflected the classic cue competition effect known as overshadowing. The time needed to make decisions increased as the number of relevant attributes increased, suggesting that reward was associated with attributes rather than whole stimuli. Fitting a family of computational models formed by crossing attribute use (optimal vs. only the best), representation (attribute vs. whole stimuli), and recency (biased or not), revealed that models that performed better when they made use of all information, represented attributes, and incorporated recency effects and cue competition. We also discuss the need to incorporate selective attention and hypothesis-testing like processes to account for results with multiple-attribute stimuli.

Diagnostic Evaluation of Patients Presenting with Rectal Bleeding by Colonoscopy

2020 ◽  
Vol 42 (1) ◽  
pp. 36-39
Author(s):  
Bala R Malla ◽  
Suyog Simkhada
Keyword(s):  
Rectal Bleeding ◽  
Diagnostic Yield ◽  
Adult Population ◽  
Common Finding ◽  
Common Causes ◽  
Optic Colonoscopy ◽  
The Common ◽  
Gastro Intestinal Tract ◽  
Histopathologic Findings ◽  
Malignant Mass

Introduction Rectal bleeding indicates the bleeding from lower gastro-intestinal tract occurring distal to ligaments of Treitz. Annual incidence of per rectal bleeding has been estimated to be 20% . Colonoscopy is the examination of choice for investigation. The objective of this study is to know the diagnostic yield of colonoscopy in cases with per rectal bleeding and to know the common causes of per rectal bleeding in adults MethodsOne hundred and twenty-nine adult patients, age more than 18years, who presented to Surgical OPD and ward of Dhulikhel Hospital during the year 2018 and 2019 were taken for the study irrespective of their sex. All the patients were subjected to fibre-optic colonoscopy after necessary preparation and the findings were recorded. Diagnosis was based on colonoscopic and histopathologic findings. ResultsA total of 129 (77 male and 52 female )patients with per rectal bleeding were evaluated with colonoscopy. The age ranged from 18 years to 79 years with the mean age 42.25 (SD+/- 15.29). Colonoscopy showed abnormalities in 102 patients (79.06%). The most common finding was hemorrhoids in 36 patients (27.90%) followed by colorectal malignant mass in 20 patients (15.50%). Polyps were diagnosed as the cause of rectal bleeding in 14 patients (10.84%). ConclusionColonoscopy has good diagnostic yield at evaluating cases with per rectal bleeding. Hemorrhoids, colorectal malignant mass and polyps are the common causes producing PR bleeding in Nepalese adult population.

scholarly journals A simple spectrophotometric method for the determination of methyldopa using p-chloranil in the presence of hydrogen peroxide

2008 ◽  
Vol 33 (3) ◽  
pp. 7-12 ◽  
Author(s):  
M. A. Gotardo ◽  
L. S. Lima ◽  
R. Sequinel ◽  
J. L. Rufino ◽  
L. Pezza ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Limit Of Quantification ◽  
Coefficients Of Variation ◽  
The Common ◽  
Interday Precision ◽  
Sensitive Spectrophotometric Method

A simple, rapid and sensitive spectrophotometric method has been developed for the determination of methyldopa in pharmaceutical formulations. The method is based on the reaction between tetrachloro-p-benzoquinone (p-chloranil) and methyldopa, accelerated by hydrogen peroxide (H2O2), producing a violet-red compound (λmax = 535 nm) at ambient temperature (25.0 ± 0.2 ºC). Experimental design methodologies were used to optimize the measurement conditions. Beer's law is obeyed in a concentration range from 2.10 x 10-4 to 2.48 x 10-3 mol L-1 (r = 0.9997). The limit of detection was 7.55 x 10-6 mol L-1 and the limit of quantification was 2.52 x 10-5 mol L-1. The intraday precision and interday precision were studied for 10 replicate analyses of 1.59 x 10-3 mol L-1 methyldopa solution and the respective coefficients of variation were 0.7 and 1.1 %. The proposed method was successfully applied to the determination of methyldopa in commercial brands of pharmaceuticals. No interferences were observed from the common excipients in the formulations. The results obtained by the proposed method were favorably compared with those given by the Brazilian Pharmacopoeia procedure at 95 % confidence level.

Modeling and forecasting the outcomes of NBA basketball games

2016 ◽  
Vol 12 (1) ◽  
Author(s):  
Hans Manner
Keyword(s):  
Time Variation ◽  
State Space Model ◽  
Dynamic State ◽  
Common Finding ◽  
Forecast Combination ◽  
Weak Evidence ◽  
Betting Market ◽  
Modeling And Forecasting ◽  
The Common ◽  
Betting Odds

AbstractThis paper treats the problem of modeling and forecasting the outcomes of NBA basketball games. First, it is shown how the benchmark model in the literature can be extended to allow for heteroscedasticity and estimation and testing in this framework is treated. Second, time-variation is introduced into the model by introducing a dynamic state space model for team strengths. The in-sample results based on eight seasons of NBA data provide weak evidence for heteroscedasticity, which can lead to notable differences in estimated win probabilities. However, persistent time variation is only found when combining the data of several seasons, but not when looking at individual seasons. The models are used for forecasting a large number of regular season and playoff games and the common finding in the literature that it is difficult to outperform the betting market is confirmed. Nevertheless, a forecast combination of model based forecasts with betting odds can lead to some slight improvements.

Effects of theFusariumspp. mycotoxins fusaric acid and deoxynivalenol on the growth ofRuminococcus albusandMethanobrevibacter ruminantium

2000 ◽  
Vol 46 (8) ◽  
pp. 692-699 ◽  
Author(s):  
Harold D May ◽  
Qingzhong Wu ◽  
Cheryl K Blake
Keyword(s):  
Antimicrobial Activity ◽  
Picolinic Acid ◽  
Fusaric Acid ◽  
Complete Recovery ◽  
Inhibitory Effect ◽  
Fusarium Spp ◽  
Ruminococcus Albus ◽  
Methanobrevibacter Ruminantium ◽  
Synergistic Inhibitory Effect ◽  
The Common

The Fusarium spp. mycotoxins fusaric acid and deoxynivalenol (DON) were tested for antimicrobial activity against Ruminococcus albus and Methanobrevibacter ruminantium. The growth of both organisms was inhibited by fusaric acid as low as 15 µg/mL (84 µM) but not by DON, at levels as high as 100 µg/mL (338 µM). No synergistic inhibitory effect was observed with DON plus fusaric acid. Neither organism was able to adapt to the fusaric acid and responses of each organism to the compound were different. The optical density (OD) maximum for R. albus, but not for M. ruminantium, was diminished after 28 days incubation at concentrations of fusaric acid below 240 µg/mL. Inhibition of R. albus started before significant growth had occurred, while M. ruminantium doubled twice before the onset of inhibition. Responses to picolinic acid, an analog of fusaric acid, were also dramatically different between the two microorganisms with M. ruminantium exhibiting a severe lag followed by a complete recovery of growth, while R. albus was only slightly inhibited with no lag. These results suggest that the mechanism of fusaric acid inhibition is specific to each microorganism. This is the first demonstration of the common mycotoxin fusaric acid inhibiting the growth of rumen bacteria.Key words: mycotoxins, fusaric acid, deoxynivalenol, Ruminococcus albus, Methanobrevibacter ruminantium.

The common finding of covert hypothyroidism at initial clinical evaluation for hyperlipoproteinemia

1991 ◽  
Vol 201 (1-2) ◽  
pp. 113-122 ◽  
Author(s):  
Charles J. Glueck ◽  
James Lang ◽  
Trent Tracy ◽  
James Speirs
Keyword(s):  
Clinical Evaluation ◽  
Common Finding ◽  
The Common ◽  
Initial Clinical Evaluation

scholarly journals Efficacy of Three Light Technologies for Reducing Microbial Populations in Liquid Suspensions

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Angeliki Birmpa ◽  
Apostolos Vantarakis ◽  
Spyros Paparrodopoulos ◽  
Paul Whyte ◽  
James Lyng
Keyword(s):  
Treatment Time ◽  
Limit Of Detection ◽  
Foodborne Pathogen ◽  
Microbial Populations ◽  
Liquid Matrix ◽  
E Coli ◽  
Bactericidal Efficacy ◽  
The Common ◽  
Liquid Suspensions ◽  
Uv C

The aim of the current study was to evaluate the effectiveness of three nonthermal light technologies (NUV-Vis, continuous UV, and HILP) on their ability to inactivateEscherichia coliK12 andListeria innocua.  E. coliK12 was selected as a representative microorganism for the enterohaemorrhagic foodborne pathogenE. coliO157:H7 andL. innocuaas a surrogate microorganism for the common foodborne pathogenListeria monocytogenes, respectively. The liquid matrix used for the disinfection experiments was a liquid matrix (MRD solution). The results of the present study show that the HILP treatment inactivated bothE. coliandL. innocuamore rapidly and effectively than either continuous UV-C or NUV-vis treatment. With HILP at 2.5 cm from the lamp,E. coliandL. innocuapopulations were reduced by 3.07 and 3.77 log10CFU/mL, respectively, after a 5 sec treatment time, and were shown to be below the limit of detection (<0.22 log10CFU/mL) following 30 sec exposure to HILP (106.2 J/cm2). These studies demonstrate the bactericidal efficacy of alternative nonthermal light technologies and their potential as decontamination strategies in the food industry.

Otological manifestations of a new familial polyostotic bone disorder

1991 ◽  
Vol 105 (2) ◽  
pp. 80-84 ◽  
Author(s):  
D. A. Adams ◽  
P. K. Gormley ◽  
A. G. Kerr ◽  
G. D. L. Smyth ◽  
P. Osterberg ◽  
...  
Keyword(s):  
Autosomal Dominant ◽  
Age Of Onset ◽  
Common Finding ◽  
Middle Ear Surgery ◽  
Ear Surgery ◽  
Radiographic Findings ◽  
Younger Age ◽  
The Family ◽  
Bone Disorder ◽  
The Common

AbstractFifty members of a family with a unique autosomal dominant bone disease were investigated. Nineteen of the family members were either known to have, or were strongly suspected of having the disease. All but one of these had a hearing loss which was conductive in the younger age group and mixed in the older members. The common finding in those who had middle ear surgery was replacement of the long process of incus by a fibrous band. The histological features were similar to those found in Paget's disease. The age of onset, distribution of lesions and radiographic findings, however, were not typical of this disorder.

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