Availability of magnesium in soils

1972 ◽  
Vol 79 (2) ◽  
pp. 197-204 ◽  
Author(s):  
A. M. Alston
Keyword(s):  
Activity Ratio ◽  
Significant Proportion ◽  
Parent Material ◽  
Single Measure ◽  
Exchangeable Bases ◽  
Soil Solutions ◽  
Ion Activity ◽  
Activity Ratios ◽  
Highly Correlated ◽  
Better Than

SUMMARYTwenty-five soils, including some subsoils, with widely differing properties were cropped with perennial ryegrass in the glasshouse, and measures of Mg availability in the soils were related to the Mg concentration in the plants.No single measure satisfactorily characterized Mg availability. The ion activity ratio, √aMg/√aca+Mg when the soil neither gained nor lost Mg on equilibration with 0–02 N-CaC12, was more highly correlated (r = 0·;75***) with Mg concentration in the ryegrass than was the best of the capacity measures tested (CaCl2-extractable Mg, r = 0·68***), particularly if the potential buffering capacity (PBCMg) of the soils was also taken into account, in which case r = 0·83***.Exchangeable Mg (r = 0·67***) was a poorer index of Mg availability than percentage Mg saturation (r = 0·73***) or exchangeable Mg expressed as a percentage of the total exchangeable bases (K, Na, Ca and Mg) in the soil (r = 0·81***). This latter quantity was better than the activity ratio as a predictor of Mg availability (r = 0·81*** compared with r = 0·75***).A significant proportion of the variation in Mg concentration in the ryegrass could be attributed to the K content of the soils, and closer correlations were obtained when K was included in the composite activity ratio, √aMg/(√aca+Mg + B. aK) (r = 0·88***) or when a term for exchangeable K was included in regression analysis with √aMg/√aca+Mg and PBCMg (r = 0·93***).The concentration of Mg in equilibrium soil solutions was generally a less satisfactory indicator of Mg availability than were the activity ratios. Soils derived from basaltic parent material had much higher contents of readily exchangeable Mg than the remainder: parent materials other than basalt had little influence on the availability of Mg in the soils. Exchangeable Mg and per cent Mg saturation were higher in gleyed soils than in freely drained soils derived from similar parent material.

Relation of blood-free to blood-inclusive postmortem lung water measurements in sheep

1985 ◽  
Vol 59 (2) ◽  
pp. 592-596 ◽  
Author(s):  
J. C. Collins ◽  
J. H. Newman ◽  
N. E. Wickersham ◽  
W. K. Vaughn ◽  
J. R. Snapper ◽  
...  
Keyword(s):  
Extravascular Lung Water ◽  
Weight Ratio ◽  
Lung Homogenate ◽  
Lung Water ◽  
Before And After ◽  
The Mean ◽  
Space Expansion ◽  
Highly Correlated ◽  
Linear Regressions ◽  
Better Than

Our purpose was to see if the postmortem weight ratio of extravascular lung water to blood-free dry lung (blood-free ratio) was related to similar ratios in blood-inclusive lung and in blood. We developed linear regressions of blood-free ratio on ratios for blood-inclusive lung and blood together and for blood-inclusive lung alone for 73 sheep studied under 11 different protocols and for two subgroups of sheep, one with plasma space expansion and the other without expansion. The relation of ratios of blood-free to blood-inclusive lungs was different between the two subgroups. Although all regressions were highly correlated, the fits of the blood-free ratio on ratios for blood-inclusive lung and blood together were better than for blood-inclusive lung alone. The mean error of prediction of extravascular lung water for all sheep was significantly less for the regression of blood-free ratio on ratios for blood and blood-inclusive lung together (11 g) than for blood-inclusive lung alone (18 g). This study shows that weights of lung homogenate and blood samples before and after simple oven drying can be used to provide accurate inexpensive estimates of postmortem extravascular lung water.

Using 10-K Text to Gauge Financial Constraints

2015 ◽  
Vol 50 (4) ◽  
pp. 623-646 ◽  
Author(s):  
Andriy Bodnaruk ◽  
Tim Loughran ◽  
Bill McDonald
Keyword(s):  
Capital Structure ◽  
Financial Constraints ◽  
Securities And Exchange Commission ◽  
Financial Constraint ◽  
Firm Characteristics ◽  
Low Correlation ◽  
Highly Correlated ◽  
Firm Attributes ◽  
The U.S ◽  
Better Than

AbstractMeasuring the extent to which a firm is financially constrained is critical in assessing capital structure. Extant measures of financial constraints focus on macro firm characteristics such as age and size, variables highly correlated with other firm attributes. We parse 10-K disclosures filed with the U.S. Securities and Exchange Commission (SEC) using a unique lexicon based on constraining words. We find that the frequency of constraining words exhibits very low correlation with traditional measures of financial constraints and predicts subsequent liquidity events, such as dividend omissions or increases, equity recycling, and underfunded pensions, better than widely used financial constraint indexes.

scholarly journals Implementation and Comparison of Two Pharmacometric Tools for Model-Based Therapeutic Drug Monitoring and Precision Dosing of Daptomycin

Pharmaceutics ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 114
Author(s):  
Justine Heitzmann ◽  
Yann Thoma ◽  
Romain Bricca ◽  
Marie-Claude Gagnieu ◽  
Vincent Leclerc ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Drug Monitoring ◽  
Joint Infection ◽  
Significant Proportion ◽  
Initial Dosage ◽  
Validation Dataset ◽  
Therapeutic Drug ◽  
Efficacy And Safety ◽  
Absolute Percent Error ◽  
Better Than

Daptomycin is a candidate for therapeutic drug monitoring (TDM). The objectives of this work were to implement and compare two pharmacometric tools for daptomycin TDM and precision dosing. A nonparametric population PK model developed from patients with bone and joint infection was implemented into the BestDose software. A published parametric model was imported into Tucuxi. We compared the performance of the two models in a validation dataset based on mean error (ME) and mean absolute percent error (MAPE) of individual predictions, estimated exposure and predicted doses necessary to achieve daptomycin efficacy and safety PK/PD targets. The BestDose model described the data very well in the learning dataset. In the validation dataset (94 patients, 264 concentrations), 21.3% of patients were underexposed (AUC24h < 666 mg.h/L) and 31.9% of patients were overexposed (Cmin > 24.3 mg/L) on the first TDM occasion. The BestDose model performed slightly better than the model in Tucuxi (ME = −0.13 ± 5.16 vs. −1.90 ± 6.99 mg/L, p < 0.001), but overall results were in agreement between the two models. A significant proportion of patients exhibited underexposure or overexposure to daptomycin after the initial dosage, which supports TDM. The two models may be useful for model-informed precision dosing.

scholarly journals Effectiveness Analysis of Working Capital on MSME Handycraft

2019 ◽  
Vol 1 (1) ◽  
pp. 127-133
Author(s):  
Laras Nada Wahyu Atika ◽  
Agus Sukoco
Keyword(s):  
Research Method ◽  
Qualitative Data ◽  
Activity Ratio ◽  
Business Development ◽  
Working Capital ◽  
Current Ratio ◽  
Working Capital Management ◽  
Business Operations ◽  
Effectiveness Analysis ◽  
Activity Ratios

This study aims to determine the effectiveness of working capital management in MSME Rozatajaya Souvenir in Sidoarjo through the analysis of liquidity and activity ratios. The research method is using descriptive qualitative. Data obtained from financial transaction records for two semesters of 2018. The results of this study found that the average Liquidity Ratio was very good which included Current Ratio of 3.02, Quick Ratio of 2.93 and Cash Ratio of 2.25. The effectiveness of working capital using the Activity Ratio was considered less effective including the average Working Capital Turnover of 1.23, Receivable Turnover of 4.22 and Turnover Inventory of 14.95 times. The findings of this study, working capital is very necessary for business operations, however, management of working capital is still not effective so it requires a strategy to increase the effectiveness of working capital in business development.

Modulation by adrenalectomy and fasting of insulin effects in perfused hindlimb muscle

1982 ◽  
Vol 242 (5) ◽  
pp. E323-E329
Author(s):  
H. Shikama ◽  
D. T. Chu ◽  
J. H. Exton
Keyword(s):  
Glycogen Content ◽  
Activity Ratio ◽  
Glycogen Synthase ◽  
Hexose Transport ◽  
Fasted State ◽  
Hindlimb Muscle ◽  
Maximal Activation ◽  
Activity Ratios ◽  
Adrenalectomized Rats

Perfused hindlimb muscle from fed adrenalectomized rats accumulated more 2-deoxyglucose at submaximal concentrations of insulin in comparison to muscle from fed normal rats. However, in the fasted state, insulin-stimulated 2-deoxyglucose uptake was largely inhibited by adrenalectomy. Basal 2-deoxyglucose uptake did not differ between fed and fasted normal or adrenalectomized rats. The changes in insulin effects caused by adrenalectomy were due to altered hexose transport as shown by measurements of 3-O-methylglucose uptake and of intracellular free and phosphorylated 2-deoxyglucose. Muscles of fasted normal and fed or fasted adrenalectomized rats showed higher basal glycogen synthase --glucose-6-P/+glucose-6-P activity ratios than those of fed normal rats probably because of decreased glycogen content. However, muscles from fed or fasted adrenalectomized rats did not show any alterations in insulin effects on the activity ratio and half-maximal activation constant (A0.5) for glucose-6-P of glycogen synthase. Because of the dissociation of the effects of insulin on hexose transport and glycogen synthase in muscle of fasted adrenalectomized rats, it is concluded that the impairment in insulin-stimulated hexose transport in these animals is due to a defect lying beyond the interaction of insulin with its receptor.

Mixture of Triclopyr and Imazapyr More Effective than Triclopyr Alone for Hardwood Forest Stand Improvement

2020 ◽  
Author(s):  
Mark A Turner ◽  
William D Gulsby ◽  
Craig A Harper
Keyword(s):  
Coastal Plain ◽  
Tree Species ◽  
Significant Proportion ◽  
Forest Stand ◽  
Liquidambar Styraciflua ◽  
Minimal Risk ◽  
Herbicide Mixture ◽  
Soil Activity ◽  
Individual Trees ◽  
Better Than

Abstract Treatment of individual trees in hardwood stands typically is conducted with herbicides that have no soil activity, such as triclopyr. However, triclopyr is not effective on some tree species. Applying a mixture of triclopyr and imazapyr would broaden the spectrum of species controlled, but nontarget mortality may be problematic as imazapyr may affect other trees through soil activity. We applied herbicide via girdle-and-spray as part of a forest stand improvement treatment in four upland hardwood stands in the Upper Coastal Plain of Alabama. We compared effects of using triclopyr alone with a mixture of triclopyr and imazapyr 18 months posttreatment. Only one untreated sweetgum (Liquidambar styraciflua) out of 440 trees was killed in the stands treated with the herbicide mixture (0.5 percent nontarget mortality rate). Nontarget mortality did not differ between treatments. However, the herbicide mixture controlled hickory (Carya spp.) and sourwood (Oxydendrum arboreum) better than triclopyr alone, with 56 percent of hickory treated with triclopyr still alive 18 months later, compared with 0 percent of hickory treated with the mixture. Our results indicate a mixture of triclopyr and imazapyr provides better control than triclopyr alone, and there is minimal risk to nontarget tree species in hardwood stands when used according to label recommendations. Study Implications Forest stand improvement (FSI) is a noncommercial practice typically conducted by cutting and using herbicide to kill undesirable trees. Consideration must be given to herbicide selection, which is based on efficacy on target species while minimizing nontarget mortality of residual trees. We found that a mixture of triclopyr and imazapyr applied via girdle-and-spray was more effective for FSI than triclopyr alone, which failed to control a significant proportion of treated hickory, and resulted in essentially no nontarget mortality in mixed hardwood stands 18 months after application.

scholarly journals Interactions between organisms and parent materials of a constructed Technosol shape its hydrostructural properties

SOIL ◽  
2016 ◽  
Vol 2 (2) ◽  
pp. 163-174 ◽  
Author(s):  
Maha Deeb ◽  
Michel Grimaldi ◽  
Thomas Z. Lerch ◽  
Anne Pando ◽  
Agnès Gigon ◽  
...  
Keyword(s):  
Parent Material ◽  
Material Composition ◽  
Positive Role ◽  
Parent Materials ◽  
Positive Effects ◽  
Available Water ◽  
Set Up ◽  
Full Factorial ◽  
Positive Effect ◽  
Better Than

Abstract. There is no information on how organisms influence hydrostructural properties of constructed Technosols and how such influence will be affected by the parent-material composition factor. In a laboratory experiment, parent materials, which were excavated deep horizons of soils and green waste compost (GWC), were mixed at six levels of GWC (from 0 to 50 %). Each mixture was set up in the presence/absence of plants and/or earthworms, in a full factorial design (n  =  96). After 21 weeks, hydrostructural properties of constructed Technosols were characterized by soil shrinkage curves. Organisms explained the variance of hydrostructural characteristics (19 %) a little better than parent-material composition (14 %). The interaction between the effects of organisms and parent-material composition explained the variance far better (39 %) than each single factor. To summarize, compost and plants played a positive role in increasing available water in macropores and micropores; plants were extending the positive effect of compost up to 40 and 50 % GWC. Earthworms affected the void ratio for mixtures from 0 to 30 % GWC and available water in micropores, but not in macropores. Earthworms also acted synergistically with plants by increasing their root biomass, resulting in positive effects on available water in macropores. Organisms and their interaction with parent materials positively affected the hydrostructural properties of constructed Technosols, with potential positive consequences on resistance to drought or compaction. Considering organisms when creating Technosols could be a promising approach to improve their fertility.

scholarly journals Evidence for a significant proportion of Secondary Organic Aerosol from isoprene above a maritime tropical forest

2011 ◽  
Vol 11 (3) ◽  
pp. 1039-1050 ◽  
Author(s):  
N. H. Robinson ◽  
J. F. Hamilton ◽  
J. D. Allan ◽  
B. Langford ◽  
D. E. Oram ◽  
...  
Keyword(s):  
Secondary Organic Aerosol ◽  
Significant Proportion ◽  
Organic Aerosol ◽  
Oxidation Products ◽  
Emission Region ◽  
Experimental Chamber ◽  
Mass Spectral ◽  
Aerosol Mass ◽  
Isoprene Oxidation ◽  
Highly Correlated

Abstract. Isoprene is the most abundant non-methane biogenic volatile organic compound (BVOC), but the processes governing secondary organic aerosol (SOA) formation from isoprene oxidation are only beginning to become understood and selective quantification of the atmospheric particulate burden remains difficult. Organic aerosol above a tropical rainforest located in Danum Valley, Borneo, Malaysia, a high isoprene emission region, was studied during Summer 2008 using Aerosol Mass Spectrometry and offline detailed characterisation using comprehensive two dimensional gas chromatography. Observations indicate that a substantial fraction (up to 15% by mass) of atmospheric sub-micron organic aerosol was observed as methylfuran (MF) after thermal desorption. This observation was associated with the simultaneous measurements of established gas-phase isoprene oxidation products methylvinylketone (MVK) and methacrolein (MACR). Observations of MF were also made during experimental chamber oxidation of isoprene. Positive matrix factorisation of the AMS organic mass spectral time series produced a robust factor which accounts for an average of 23% (0.18 μg m−3), reaching as much as 53% (0.50 μg m−3) of the total oraganic loading, identified by (and highly correlated with) a strong MF signal. Assuming that this factor is generally representative of isoprene SOA, isoprene derived aerosol plays a significant role in the region. Comparisons with measurements from other studies suggest this type of isoprene SOA plays a role in other isoprene dominated environments, albeit with varying significance.

Fermi Level Inhomogeneities on GaAs(110) Surface Imaged with a Photoelectron Microscope

1992 ◽  
Vol 260 ◽  
Author(s):  
Changyoung Kim ◽  
Paul L. King ◽  
Piero Pianetta
Keyword(s):  
Fermi Level ◽  
Optical Microscope ◽  
Level Energy ◽  
Band Bending ◽  
Highly Correlated ◽  
P Type ◽  
Low Coverage ◽  
Lateral Variations ◽  
Surface Fermi Level ◽  
Better Than

ABSTRACTA photoelectron microscope operating with a retarding field analyzer has been used to exploit core level energy shifts due to band bending in order to directly image Fermi level variations on n- and p-type cleaved GaAs(110) surfaces. Fermi level maps resolved to better than 10 um indicate lateral variations in the surface Fermi level which are often quite abrupt. In agreement with earlier, lower resolution work [1], Fermi level topography is found to be highly correlated with surface roughness as characterized by SEM, optical microscope and stylus profi lometer. The largest defect derived pinnings encountered to date resut in the Fermi level lying 0.5 eV above the VBM for both n- and p-type GaAs. Low coverage In evaporations have the. effect of reducing Fermi level contrast as Fermi levels in formerly unpinned regions move into the gap.

Comparison of Granite, Tuff, and Basalt as Geologic Media for Long-Term Storage of High-Level Nuclear Waste

1990 ◽  
Vol 212 ◽  
Author(s):  
D. E. Grandstaff ◽  
V. J. Grassi ◽  
A. C. Lee ◽  
G. C. Ulmer
Keyword(s):  
Nuclear Waste ◽  
Nuclear Waste Repository ◽  
Long Term Storage ◽  
Hydrothermal Experiments ◽  
Ion Activity ◽  
Activity Ratios ◽  
High Level Nuclear Waste ◽  
High Level ◽  
Term Storage

ABSTRACTSystematic differences in pH, cation/proton ion activity ratios, and redox have been observed between solutions produced in rock-water hydrothermal experiments with tuff, granite, and basalt. Stable pH values in tuff-water experiments may be as much as 1.5 pH units more acidic than basalt-water experiments at the same temperature and ionic strength. Redox (log fO2) values in 300°C tuff experiments are 4–7 orders of magnitude more oxidizing than basalt experiments and ca. 4 log units more oxidizing than the magnetite-hematite buffer. Such fluid differences could significantly affect the performance of a high-level nuclear waste repository and should be considered in repository design and siting.

Sign in / Sign up

Export Citation Format

Share Document