bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical, Molecular, and Prognostic Significance of WHO Type inv(3)(q21q26.2)/t(3;3)(q21;q26.2) and Various Other 3q Abnormalities in Acute Myeloid Leukemia
Authors: Lugthart Sanne , Gröschel Stefan , Beverloo H. Berna , Kayser Sabine , Valk Peter J.M. , van Zelderen-Bhola Shama Lydia , Jan Ossenkoppele Gert , Vellenga Edo , van den Berg-de Ruiter Eva , Schanz Urs , Verhoef Gregor , Vandenberghe Peter , Ferrant Augustin , Köhne Claus-Henning , Pfreundschuh Michael , Horst Heinz A. , Koller Elisabeth , von Lilienfeld-Toal Marie , Bentz Martin , Ganser Arnold , Schlegelberger Brigitte , Jotterand Martine , Krauter Jürgen , Pabst Thomas , Theobald Matthias , Schlenk Richard F. , Delwel Ruud , Döhner Konstanze , Löwenberg Bob , Döhner Hartmut
Published: July 2010

Purpose

Acute myeloid leukemia (AML) with inv(3)(q21q26.2)/t(3;3)(q21;q26.2) [inv(3)/t(3;3)] is recognized as a distinctive entity in the WHO classification. Risk assignment and clinical and genetic characterization of AML with chromosome 3q abnormalities other than inv(3)/t(3;3) remain largely unresolved.

Patients and Methods

Cytogenetics, molecular genetics, therapy response, and outcome analysis were performed in 6,515 newly diagnosed adult AML patients. Patients were treated on Dutch-Belgian Hemato-Oncology Cooperative Group/Swiss Group for Clinical Cancer Research (HOVON/SAKK; n = 3,501) and German-Austrian Acute Myeloid Leukemia Study Group (AMLSG; n = 3,014) protocols. EVI1 and MDS1/EVI1 expression was determined by real-time quantitative polymerase chain reaction.

Results

3q abnormalities were detected in 4.4% of AML patients (288 of 6,515). Four distinct groups were defined: A: inv(3)/t(3;3), 32%; B: balanced t(3q26), 18%; C: balanced t(3q21), 7%; and D: other 3q abnormalities, 43%. Monosomy 7 was the most common additional aberration in groups (A), 66%; (B), 31%; and (D), 37%. N-RAS mutations and dissociate EVI1 versus MDS1/EVI1 overexpression were associated with inv(3)/t(3;3). Patients with inv(3)/t(3;3) and balanced t(3q21) at diagnosis presented with higher WBC and platelet counts. In multivariable analysis, only inv(3)/t(3;3), but not t(3q26) and t(3q21), predicted reduced relapse-free survival (hazard ratio [HR], 1.99; P < .001) and overall survival (HR, 1.4; P = .006). This adverse prognostic impact of inv(3)/t(3;3) was enhanced by additional monosomy 7. Group D 3q aberrant AML also had a poor outcome related to the coexistence of complex and/or monosomal karyotypes and cryptic inv(3)/t(3;3).

Conclusion

Various categories of 3q abnormalities in AML can be distinguished according to their clinical, hematologic, and genetic features. AML with inv(3)/t(3;3) represents a distinctive subgroup with unfavorable prognosis.
The time to measure positional information: maternal Hunchback is required for the synchrony of the Bicoid transcriptional response at the onset of zygotic transcription
Authors: Porcher Aude , Abu-Arish Asmahan , Huart Sébastien , Roelens Baptiste , Fradin Cécile , Dostatni Nathalie
Published: July 2010

It is widely accepted that morphogenetic gradients determine cell identity by concentration-dependent activation of target genes. How precise is each step in the gene expression process that acts downstream of morphogens, however, remains unclear. The Bicoid morphogen is a transcription factor directly activating its target genes and provides thus a simple system to address this issue in a quantitative manner. Recent studies indicate that the Bicoid gradient is precisely established in Drosophila embryos after eight nuclear divisions (cycle 9) and that target protein expression is specified five divisions later (cycle 14), with a precision that corresponds to a relative difference of Bicoid concentration of 10%. To understand how such precision was achieved, we directly analyzed nascent transcripts of the hunchback target gene at their site of synthesis. Most anterior nuclei in cycle 11 interphasic embryos exhibit efficient biallelic transcription of hunchback and this synchronous expression is specified within a 10% difference of Bicoid concentration. The fast diffusion of Bcd-EGFP (7.7 μm2/s) that we captured by fluorescent correlation spectroscopy in the nucleus is consistent with this robust expression at cycle 11. However, given the interruption of transcription during mitosis, it remains too slow to be consistent with precise de novo reading of Bicoid concentration at each interphase, suggesting the existence of a memorization process that recalls this information from earlier cycles. The two anterior maternal morphogens, Bicoid and Hunchback, contribute differently to this early response: whereas Bicoid provides dose-dependent positional information along the axis, maternal Hunchback is required for the synchrony of the response and is therefore likely to be involved in this memorization process.
New heterogeneous test statistics for the unbalanced fixed‐effect nested design
Authors: Guo Jiin‐Huarng , Billard L. , Luh Wei‐Ming
Published: July 2010

When the underlying variances are unknown or/and unequal, using the conventional F test is problematic in the two‐factor hierarchical data structure. Prompted by the approximate test statistics (Welch and Alexander–Govern methods), the authors develop four new heterogeneous test statistics to test factor A and factor B nested within A for the unbalanced fixed‐effect two‐stage nested design under variance heterogeneity. The actual significance levels and statistical power of the test statistics were compared in a simulation study. The results show that the proposed procedures maintain better Type I error rate control and have greater statistical power than those obtained by the conventional F test in various conditions. Therefore, the proposed test statistics are recommended in terms of robustness and easy implementation.
Developing guidelines for good practice in participatory arts-in-health-care contexts
Authors: White Mike
Published: July 2010

As the field of arts in health grows in scale and diversity, it needs to affirm a set of shared principles and describe what constitutes best practice. This article recounts the production of guidelines for good practice in participatory arts in health care, based on consultations with
practitioners in the arts and health sectors in Ireland in 20082009. It considers why it was difficult and inappropriate to formalize a code of practice but explains how guidelines for good practice within an ethical framework were collectively agreed. It argues that the arts in health practitioner
is not the individual artist but rather a partnership between diverse professional interests with common principles and values that govern engagement with participants and inform the planning, delivery and evaluation of the practice. It considers issues of quality and risk and proposes that
benchmarking best practice should be the next step.
The Total Branch Length of Sample Genealogies in Populations of Variable Size
Authors: Eriksson A , Mehlig B , Rafajlovic M , Sagitov S
Published: July 2010

We consider neutral evolution of a large population subject to changes in its population size. For a population with a time-variable carrying capacity we study the distribution of the total branch lengths of its sample genealogies. Within the coalescent approximation we have obtained a general expression—Equation 20—for the moments of this distribution with a given arbitrary dependence of the population size on time. We investigate how the frequency of population-size variations alters the total branch length.
Challenge! Health Promotion/Obesity Prevention Mentorship Model Among Urban, Black Adolescents
Authors: Black Maureen M. , Hager Erin R. , Le Katherine , Anliker Jean , Arteaga S. Sonia , DiClemente Carlo , Gittelsohn Joel , Magder Laurence , Papas Mia , Snitker Soren , Treuth Margarita S. , Wang Yan
Published: July 2010

OBJECTIVES:

The objective of this study was to evaluate a 12-session home/community-based health promotion/obesity prevention program (Challenge!) on changes in BMI status, body composition, physical activity, and diet.

METHODS:

A total of 235 black adolescents (aged 11–16 years; 38% overweight/obese) were recruited from low-income urban communities. Baseline measures included weight, height, body composition, physical activity (PA), and diet. PA was measured by 7-day play-equivalent physical activity (≥1800 activity counts per minute). Participants were randomly assigned to health promotion/obesity prevention that is anchored in social cognitive theory and motivational interviewing and was delivered by college-aged black mentors or to control. Postintervention (11 months) and delayed follow-up (24 months) evaluations were conducted. Longitudinal analyses used multilevel models with random intercepts and generalized estimating equations, controlling for baseline age/gender. Stratified analyses examined baseline BMI category.

RESULTS:

Retention was 76% over 2 years; overweight/obese status declined 5% among intervention adolescents and increased 11% among control adolescents. Among overweight/obese youth, the intervention reduced total percentage of body fat and fat mass and increased fat-free mass at delayed follow-up and increased play-equivalent physical activity at postintervention but not at delayed follow-up. Intervention adolescents declined significantly more in snack/dessert consumption than control adolescents at both follow-up evaluations.

CONCLUSIONS:

At postintervention, there were intervention effects on diet and PA but not BMI category or body composition. At delayed follow-up, dietary changes were sustained and the intervention prevented an increase in BMI category. Body composition was improved for overweight/obese youth. Changes in body composition follow changes in diet and PA and may not be detected immediately after intervention.
Primary Health Care Providers' Advice for a Dental Checkup and Dental Use in Children
Authors: Beil Heather A. , Rozier R. Gary
Published: July 2010

OBJECTIVE:

In this study we estimated factors associated with children being advised to see the dentist by a doctor or other health provider; tested for an association between the advisement on the likelihood that the child would visit the dentist; and estimated the effect of the advisement on dental costs.

METHODS:

We identified a sample of 5268 children aged 2 to 11 years in the 2004 Medical Expenditures Panel Survey. A cross-sectional analysis with logistic regression models was conducted to estimate the likelihood of the child receiving a recommendation for a dental checkup, and to determine its effect on the likelihood of having a dental visit. Differences in cost for children who received a recommendation were assessed by using a linear regression model. All analyses were conducted separately on children aged 2 to 5 (n = 2031) and aged 6 to 11 (n = 3237) years.

RESULTS:

Forty-seven percent of 2- to 5-year-olds and 37% of 6- to 11-year-olds had been advised to see the dentist. Children aged 2 to 5 who received a recommendation were more likely to have a dental visit (odds ratio: 2.89 [95% confidence interval: 2.16–3.87]), but no difference was observed among older children. Advice had no effect on dental costs in either age group.

CONCLUSIONS:

Health providers' recommendation that pediatric patients visit the dentist was associated with an increase in dental visits among young children. Providers have the potential to play an important role in establishing a dental home for children at an early age. Future research should examine potential interventions to increase effective dental referrals by health providers.
Reducing Wasting in Young Children With Preventive Supplementation: A Cohort Study in Niger
Authors: Isanaka Sheila , Roederer Thomas , Djibo Ali , Luquero Francisco J. , Nombela Nohelly , Guerin Philippe J. , Grais Rebecca F.
Published: July 2010

OBJECTIVE:

To compare the incidence of wasting, stunting, and mortality among children aged 6 to 36 months who are receiving preventive supplementation with either ready-to-use supplementary foods (RUSFs) or ready-to-use therapeutic foods (RUTFs).

SUBJECTS AND METHODS:

Children aged 6 to 36 months in 12 villages of Maradi, Niger, (n = 1645) received a monthly distribution of RUSFs (247 kcal [3 spoons] per day) for 6 months or RUTFs (500-kcal sachet per day) for 4 months. We compared the incidence of wasting, stunting, and mortality among children who received preventive supplementation with RUSFs versus RUTFs.

RESULTS:

The effectiveness of RUSF supplementation depended on receipt of a previous preventive intervention. In villages in which a preventive supplementation program was previously implemented, the RUSF strategy was associated with a 46% (95% confidence interval [CI]: 6%–69%) and 59% (95% CI: 17%–80%) reduction in wasting and severe wasting, respectively. In contrast, in villages in which the previous intervention was not implemented, we found no difference in the incidence of wasting or severe wasting according to type of supplementation. Compared with the RUTF strategy, the RUSF strategy was associated with a 19% (95% CI: 0%–34%) reduction in stunting overall.

CONCLUSION:

We found that the relative performance of a 6-month RUSF supplementation strategy versus a 4-month RUTF strategy varied with receipt of a previous nutritional intervention. Contextual factors will continue to be important in determining the dose and duration of supplementation that will be most effective, acceptable, and sustainable for a given setting.
Emergency Department Visits for Medical Device-Associated Adverse Events Among Children
Authors: Wang Cunlin , Hefflin Brock , Cope Judith U. , Gross Thomas P. , Ritchie Mary Beth , Qi Youlin , Chu Jianxiong
Published: July 2010

OBJECTIVES:

The purposes of this study were to provide national estimates of emergency department (ED) visits for medical device-associated adverse events (MDAEs) in the pediatric population and to characterize these events further.

METHODS:

ED medical record reports from the National Electronic Injury Surveillance System All Injury Program database from January 1, 2004, through December 21, 2005, were reviewed. MDAEs among pediatric patients were identified, and data were abstracted. National estimates for pediatric MDAEs were determined according to medical specialty, device category and class, injury diagnosis, and patient characteristics and outcome.

RESULTS:

The total estimated number of pediatric MDAEs during the 24-month period was 144799 (95% confidence interval: 113051–183903), involving devices from 13 medical specialties. Contact lenses accounted for most MDAEs (23%), followed by hypodermic needles (8%). The distribution of MDAEs according to medical specialty varied according to age subgroup. The most-prevalent types of injuries included contusions/abrasions, foreign-body intrusions, punctures, lacerations, and infections. The most-frequently affected body parts were the eyeball, pubic region, finger, face, and ear. The majority of pediatric MDAEs involved class II (moderate-risk) devices. The incidence of pediatric MDAEs decreased with increasing age from early to late childhood and then spiked after 10 years of age. More girls than boys were affected at older ages (16–21 years) and more boys than girls at younger ages (≤10 years). Hospitalizations were more likely to involve invasive or implanted devices.

CONCLUSIONS:

This study provides national estimates of pediatric MDAEs resulting in ED visits and highlights the need to develop interventions to prevent pediatric device-related injuries.
Disappearance of 2,4‐dichlorophenoxyacetic Acid and 2,4,5‐trichlorophenoxyacetic Acid from Soil
Authors: Newman A. S. , Thomas J. R. , Walker R. L.
Published: July 2010

2,4‐D was incubated in the laboratory with different depths of Duffield silty clay loam, and its disappearance therefrom was determined by a cucumber root elongation test. The lag period before onset of decomposition and the time required for complete decomposition of 2,4‐D increased with depth. The lag period varied from 14 days in the 0‐ to 6‐inch sample to 42 days in the 18‐ to 21‐inch sample. On retreatment with 2,4‐D the differences among the depths were much smaller than with the original treatment.

Disappearance of 2,4‐D and of 2,4,5‐T under field conditions was studied in plots treated with these compounds at rates of 0.0, 0.2, 1.0, and 2.5 grams per square yard in 1949, and retreated with one gram per square yard in 1950. 2,4,5‐T persisted more than 19 weeks; its persistence was not influenced by previous treatment. The effective concentration of 2,4‐D was reduced more rapidly in soils in which it had decomposed previously. This compound persisted 5 and 6 weeks, respectively, in plots which had and had not been treated previously. A substance which stimulated root elongation of cucumber was produced during the decomposition of 2,4‐D.
The Effects of Plant Residue Cover and Clod Structure on Soil Losses by Wind
Authors: Englehorn C. L. , Zingg A. W. , Woodruff N. P.
Published: July 2010

Tests were conducted in the field to determine the interrelationships of surface drag, surface roughness, plant residue cover, percent of soil material less than 0.42 mm in diameter, and soil loss obtained by means of a portable wind tunnel. The tests were conducted at Garden City, Colby, and Manhattan, Kans. on plots prepared especially to obtain a range in residue cover over a range in soil structure.

The data obtained were analyzed according to standard multiple regression and correlation procedure and presented in terms of regression equations. The exponential regression equations provided a satisfactory expression of the functional relationships. Factors effecting variation in results between the different locations were cited.

The regression equations illustrate the effect of each factor on soil loss. On the basis of relationships secured at three locations, an exponential equation approximating the results of the tests as a whole was developed. In this equation, soil loss, X, in pounds per acre is shown to vary directly as the 2.5 power of the surface drag of the wind and the 3.5 power of the percent of soil fractions less than 0.42 mm in diameter. It varied inversely as the 0.8 power of the weight of surface residue. A simplified clod structure‐residue index of soil loss, wherein the surface drag of the wind is held constant at 3,000 pounds per acre, is presented.
Hydraulic Gradients During Infiltration in Soils
Authors: Miller R. D. , Richard Felix
Published: July 2010

A technique for direct measurement of hydraulic head in rapidly changing systems was applied to the infiltration of water into artificially packed columns of dry soil including three California soils and a sample of silica flour. Results indicate that the transmitting zone in each soil was a region of relatively uniform hydraulic gradient which was greater than unity but decreased with time and might approach unity as a limit. At corresponding stages of infiltration, the magnitudes of the gradients in the transmitting zones differed for the various materials.
Microbial Turnover of Phosphorus in Soil
Authors: Johnson D. D. , Broadbent F. E.
Published: July 2010

The phosphorus cycle in soils has been shown to be closely related to the carbon and nitrogen cycles. The investigation reported is an attempt to evaluate the effect of the energy status of the soil on this phosphorus cycle. A concept of a metabolic pool in the soil from which microbial, plant, and chemical processes takadknorganic phosphorus is presented. The addition of radioactive phosphorus to this pool and its subsequent uptake by the soil processes would allow the various fractions of the soil phosphorus which are actively turning over to be identified. The procedure used to evaluate this theory involved the addition of radiophosphorus and incubation of soil samples for various periods of time, after which the soil was leached with acid and then treated with cold and hot alkali solutions, the alkali solutions being further fractionated by the addition of acid. Total phosphorus and total radiophosphorus was determined on all fractions. The analysis of the data shows that certain of these soil phosphorus fractions do undergo rapid turnover. The possible importance of these rapidly turning‐over fractions to the growth of higher plants is suggested.
Characteristics of Some Brown Podzolic Profiles in the Central Lowland of Connecticut and Massachusetts
Authors: Swanson C. L. W. , Shearin A. E. , Bourbeau G. A.
Published: July 2010

Field and laboratory data are presented on six representative Brown Podzolic soils occurring in the Central Lowland of Connecticut and Massachusetts. The environment of this area has been cited as producing modal Brown Podzolic soils. The soils studied have only a few faintly expressed Bleicherde or none at all and no visual evidence of an orterde. Little textural profile development was found in these soils. The pH, organic content, and morphology of the profile may be considered characteristic of Brown Podzolic soils. It is postulated that the high silt content in the solum of some of the soils studied is of eolian origin since so little weathering has taken place as indicated by the low clay content and near absence of colloid accumulation in the B horizon. X‐ray diffraction patterns show little to be the predominant clay mineral in the Merrimac and Wethersfield soils studied. Chlorite, montmorillonite, gibbsite, and kaolinite occur in decreasing order of abundance.
Characteristics of Some Podzolic Soils of the Northeastern United States
Authors: Lyford W. H.
Published: July 2010

Podzols, Brown Podzolic, Gray‐Brown Podzolic, and Red‐Yellow Podzolic soils are the zonal soils of greatest extent in the 12 Northeastern States. It is the purpose of this paper to review briefly the characteristics of these zonal soils, to indicate current ideas, and to point out some possible long time trends in genesis. The paper is a summary of many field observations in the area by the author.

Podzols occupy the greatest area and many appear to be polygenetic. Brown Podzolic soils are sufficiently different from Podzols on the basis of chemical and morphological evidence to warrant separation at the great zonal group level. Some Gray‐Brown Podzolic soils are also polygenetic. It is rather striking that they occur chiefly on calcareous parent materials north of the Wisconsin terminal moraine, but are on acid parent material to the south of the moraine. Red‐Yellow Podzolic soils occur on remnants of very old land surfaces and, although limited in area, are more widespread than was once thought. The trend of soil development in the Northeast would seem to be toward Podzols and Red‐Yellow Podzolic soils. Brown Podzolic and Gray‐Brown Podzolic soils perhaps should be considered as transition stages.
The Influence of Soil Moisture Tension on Vapor Movement of Soil Water
Authors: Jones Harold E. , Kohnke Helmut
Published: July 2010

The intent of this research was to study the role of soil moisture tension in water vapor movement within the soil.

All studies were conducted in the laboratory. Vapor movement was effected by vapor pressure differences obtained through the application of a sharp temperature interface at the midpoint of horizontal soil columns. The influences of such factors as soil porosity, initial moisture content, and vapor pressure gradients were determined.

The movement of water vapor in the two soils and four soil separates studied increased rapidly with moisture tension up to a certain level, then decreased sharply.

The pF at which vapor movement was initiated and at which maximum movement occurred increased with a decrease in particle size.

The volume of unsaturated soil pores, not their size, seems to govern the soil moisture content at which vapor movement begins.

The volume of vapor movement in disturbed soil samples under a given vapor pressure gradient is regulated by the balance of unsaturated pore space, evaporating surfaces, and moisture reserve existing in the soil.

Maximum vapor movement occurred at moisture tensions slightly below the wilting point suggesting a mechanism by which plants may resist drought injury.

Temperature induced vapor pressure gradients seem to be mainly responsible for water vapor transfer in soils.
The Effect of Ammonium Nitrate Applications to Field Soils on Nodulation, Seed Yield, and Nitrogen and Oil Content of the Seed of Soybeans
Authors: Lyons J. C. , Earley E. B.
Published: July 2010

A 2‐year field study was conducted to determine the possibility of supplementing soil and symbiotically‐fixed nitrogen of soybeans with nitrogen fertilizer.

In 1947, during a hot dry growing season marked responses were obtained from added nitrogen. The number of nodules per plant decreased 80 to 90%, there were appreciable increases in seed yields, nitrogen content of the seed increased, and oil content decreased.

In 1949, with adequate rainfall, moderate temperatures, and 30 to 40 days additional growing season there was little to no response to added nitrogen. The number of nodules per plant on the untreated plots was larger than in 1947, and the largest application of ammonium nitrate resulted in only a 35% decrease in number of nodules. The yield of seed increased very little, and no change occurred in the nitrogen and oil contents of the seed.

A comparison of three dates of side‐dressing with plow‐down treatments indicated that the most effective utilization occurred with plow‐down applications.

This experiment helps explain some of the variation in response of soybeans to nitrogen fertilizers. Rainfall and temperature conditions during the growing season apparently have a direct influence on the sufficiency of symbiotically‐fixed nitrogen for maximum yields, thus indirectly influencing the response to added nitrogen.
Mineral Composition of the Clay Fraction: III. of Some Main Soil Groups of China
Authors: Hseung Y. , Jackson M. L.
Published: July 2010

Eighteen soil samples from China, representing Great Soil Groups of varying degree of weathering from Desert Soils to a Latosol were analyzed by fractionation at 5, 2, 0.2, and 0.08 µ, and application of X‐ray diffraction and elemental analysis procedures. In the weighted mean of these fractions of Pedocals, illite constituted 35%; of Pedalfers, vermiculite (5–12%) and kaolinite (11–50%) were more abundant; of Podsolic soils, vermiculite (5–12%) and kaolinite (11–21%) were abundant, and illite was also still important (15–23%); of the Latosols, gibbsite (25%) and hematite (23%) were dominant, but kaolinite, vermiculite, and illite were present. Montmorinic dioctahedral illite was found in the Desert soils and shows a young stage of soil weathering. The content of the montmorin series was low in most of the soils studied, attributed to drier cool climates than in the regions of the United States where it commonly occurs. The weathering mean is suggested for use in the measurement of the degree of soil mineral weathering. The weathering mean ranges from 2.5 to 11.0 for the soils of China examined.
The Effect of Partial Pressure of Oxygen on Some Soil Nitrogen Transformations
Authors: Broadbent F. E. , Stojanovic B. F.
Published: July 2010

Two New York soils were incubated under conditions permitting control of the partial pressure of oxygen in a stream of gas passing continuously through the soil sample. Ammonium and nitrate salts and organic materials were added in various amounts and combinations and distribution of inorganic nitrogen determined at the end of each experiment. In two experiments the N15 tracer was used to determine accurately the fate of added nitrate.

Immobilization of added inorganic nitrogen occurred whether or not ample nitrogen was available to the soil population, probably due to preferential assimilation. Reduction of nitrate to ammonia was almost negligible at all oxygen concentrations, though slightly higher under anaerobic conditions than otherwise. Denitrification of added nitrate was inversely related to partial pressure of oxygen, but was of appreciable magnitude even under fully aerobic conditions. No evidence of nitrogen loss from the soil was obtained when ammonium salts were added.

The experimental findings are compatible with the theory that nitrous oxide in the earth's atmosphere arises from the soil, and that denitrification is of major importance in the nitrogen cycle.
Physicochemical Investigations of Clay‐adsorbed Organic Colloids: II
Authors: Stevenson F. J. , Van Winkle Q. , Martin W. P.
Published: July 2010

The purpose of this study was to determine the sedimentation velocity and free diffusion behavior of humic acid extracted from Miami clay with neutral sodium pyrophosphate solution. In addition the organic colloids extracted from several soils of the Miami catena were analyzed using the eletrophoretic technique.

The electrophoresis examination indicated that the organic colloids extracted from the clay fractions of a Brookston, Crosby, and Miami soil were similar. In all cases it appeared that the extract consisted mainly of dark colored humic acid, with two additional colloids present in very small quantities.

The sedimentation velocity and free diffusion study showed that the humic colloid isolated from Miami clay was polydisperse with respect to particle size. The following data were obtained for the colloid dissolved in a water solution:

Sedimentation constant s20 2.8 × 10‐13 cm/sec/dyne

Diffusion constant D20 3.9 × 10‐7 sq cm/sec

Partial specific volume V 0.67

Frictional coefficient f/f0 2.3

Weight‐average molecular weight Mw 53,000
Correlation Between Nitrifiable Nitrogen and Yield Response of Corn to Nitrogen Fertilization on Iowa Soils
Authors: Fitts J. W. , Bartholomew W. V. , Heidel H.
Published: July 2010

Nitrification rate is proposed as a procedure for evaluating nitrogen requirements of soils for the production of corn. By the use of a modified nitrification method the rate of nitrate production was compared with the response of corn to nitrogen fertilizer in a series of experiments conducted in Iowa over a period of seven years. A significant correlation was obtained between nitrification rate and the response of corn to the application of 40 to 60 lbs. of nitrogen per acre. The data serve to stress the influence of plant population density on the magnitude of yield response to nitrogen. At comparable rates of nitrification considerably higher yield responses to fertilization were obtained where the plant population was high than where it was low. In all population groups, however, a profitable yield response to nitrogen fertilization was obtained where the nitrification rate was less than 40 ppm. On fields with thick stands, profitable yield increases were generally obtained when the nitrification rate was less than 50 ppm.
Soil Mapping by Stereoscopic Interpretation of Airphotos
Authors: Pasto Jerome K.
Published: July 2010

In many areas it appears possible to map soils, with some generalization, by combining stereoscopic interpretation of aerial photographs with field checks. As a test of this technique, the soil series were mapped on 4000 acres in the glaciated region of southern New York. The area was then mapped on foot in the usual manner. The stereo results came remarkably close to representing the true field conditions.

Essentially the method relies on knowledge of the kinds of soil which occur in the area, then identifying certain features of the land related to soil patterns. The major features on airphotos important to soil identification are the landscape or land form, slope, position, color tone, vegetation, drainage pattern, and land use.

In complex areas soil mapping obviously depends on field examination, but where stereo methods can be applied more maps could be made available for use, with a big saving in time and money.
Field Structure of Cultivated Soils with Special Reference to Erodibility by Wind
Authors: Chepil W. S.
Published: July 2010

A study of structure and erodibility of soil by wind was carried out on wind eroded and residual soil materials in a condition usually existing in the field and after sampling, cultivating, and dry sieving.

Field structure and erodibility of soils varied greatly with as little as 1 inch of simulated rainfall. In soils undisturbed by cultivation after rain, four distinct phases of structure were found, all of which possess different degrees of erodibility by wind. These phases are the primary aggregates (water‐stable aggregates), the secondary aggregates (granules and clods), the surface crust, and the consolidated soil material between the secondary aggregates.

The abrasive action of wind erosion was shown to be one of the most serious aspects of erodibility by wind.

The mechanical stability, that is, the resistance of a soil to breakdown by mechanical forces such as cultivation or sieving, was found to vary directly with the resistance of the soil to abrasion by wind‐blown sand. Mechanical stability was greatest for drift particles (sand grains and water‐stable aggregates mostly), less for the secondary aggregates, followed in order by the surface crust, the consolidated materials between the secondary aggregates, and lastly the consolidated materials, if any, which held drifted particles together after they were wetted and dried.

The amount of dispersed fine silt was found to be a primary factor influencing the formation of the surface crust and the consolidation of the soil body after it was wetted and dried. A fraction of clay size, being much less dispersible than silt, was found to be the primary factor of secondary aggregate formation. Water‐dispersible silt and clay were responsible in large measure for the resistance of the soil to erosion by wind. Although the amount of erosion was limited to some degree by the presence of water‐stable aggregates too large to be moved by wind, it was found that cultivated dryland soils lack these aggregates in sufficient amounts. The resistance of these soils to wind action was found to depend primarily on their ability to form secondary aggregates, or clods.

The secondary aggregates preserved their identity below the surface even after repeated wetting and drying in the field. It was concluded, therefore, that the physical condition of the soil is indicated as well or better by methods such as dry sieving, which primarily measure the state of the secondary aggregates, than by methods that measure the state of the primary aggregates.
Factors Affecting Distributions of Cations in Clay‐Electrolyte Systems
Authors: Harward Moyle E. , Mehlich A.
Published: July 2010

Investigations were conducted on some factors which influence distributions of K and Ca in clay‐electrolyte systems.

The method involved the additions of acids to variously base saturated suspensions of Utah bentonite and Kamec halloysite. The distributions of K and Ca were determined from an analysis of the supernatant liquid after equilibrium was obtained.

The results suggest that the effect of Ca‐saturation upon the replacement of K is related to type of colloid and to the amount of acid added. When HCl in amounts greater than 0.09 symmetry were added to Utah bentonite systems, the amount of K in solution increased with Ca‐saturation, reached a maximum and then decreased. The degree of Ca‐saturation at which the maximum amount of K was in solution was dependent upon the amount of acid added to these systems.

Appreciable amounts of K and Ca were in solution when no electrolyte was added. Under these conditions K and Ca in solution increased with increasing degree of Ca‐saturation and they were greater in Kamec halloysite than in Utah bentonite systems. When small amounts of acid were added, however, the amounts of K and Ca in solution were greater for the Utah bentonite than for the Kamec halloysite systems at low degrees of base saturation while the reverse was true at high degrees of saturation. The addition of small amounts of acid did not change the trend of K in solution increasing with Ca‐saturation for both clays.

The influence of some partially ionized solution species upon the replacement of K was investigated by using acids with different dissociation constants. The data suggested that differences between acids will only be evident if the pH of the equilibrium solutions are below that at which the acids are ordinarily neutralized.
The Influence of Sodium, Potassium, and Ammonium Ions on the Respiration of Azotobacter chroococcum as Related to the Composition of the Growth Medium
Authors: Burns C. M. , Harris John O.
Published: July 2010

Azotobacter chroococcum was able to grow in modified culture media deficient in potassium and sodium ions. Respiratory activity of the resulting cells in the presence of added potassium or sodium ions was influenced by the composition of the growth medium. Ammonium ions gave increased oxygen uptake regardless of the growth medium. When the cells were grown in ammonium‐Ashby's medium potassium stimulated while sodium retarded oxygen uptake. Cells harvested from the sodium medium exhibited decreased respiratory activity in the presence of potassium ions. Potassium stimulation of respiration of cells grown in the ammonium rich medium appeared to be of a general nature rather than specific for a single enzymatic process. The presence of potassium ions increased the rate at which the cells could adapt themselves to heterologous respiratory substrates.
Using Soil Survey Information in Land Valuation for Tax Assessment
Authors: Aandahl Andrew R.
Published: July 2010

Soil surveys are a tool for improving the assessment of rural lands. The soil classification provides the means for utilizing factual information in making the necessary physical predictions of soil productivity. With these predictions economic ratings for different uses of each soil can be made. The soil map showing the location and extent of each soil permits the application of these economic ratings to specific tracts of land resulting in the first approximation of the assessed value. These must be adjusted for roads, schools, and other factors affecting the value.
Foliar Feeding of Corn with Urea Nitrogen
Authors: Foy C. D. , Montenegro G. , Barber S. A.
Published: July 2010

The application of supplemental nitrogen to corn by the use of urea foliar sprays was investigated. Injury in the form of marginal leaf burn was dependent upon both the concentration of the solution and the rate of application. The amount of injury could also be modified by additions of sugar, calcium hydroxide and potassium bicarbonate. Yield response of corn to foliar applied nitrogen was no greater than to the same amount of nitrogen applied as a side dressing. When injury occurred the yield response was reduced. The cause of the marginal leaf burn was investigated. Ammonia or nitrites did not appear to cause the injury. It was postulated that some product or a number of products of ammonia metabolism caused the injury. The beneficial effect of sucrose was believed to be due to the decreased rate of urea absorption and an increased rate of urea translocation within the plant.
Selective Loss of Plant Nutrients by Erosion
Authors: Stoltenberg N. L. , White J. L.
Published: July 2010

Losses of soil and plant nutrients have been determined for six 3‐acre watersheds under prevailing farming practices, and six 3‐acre watersheds under a conservation farming system. The period reported, 1947–1950, was found to be close to normal with respect to rainfall. Comparative loss data was also obtained for the four crops represented on the watersheds, namely, corn, soybeans, wheat, and meadow.

Erosion was found to be a selective process such that the eroded material contained considerably more plant nutrients than the soil from which it was eroded. This selective process resulted in a decrease in soil fertility, a decrease in organic matter, and changes in texture. The selective nature of the erosion process was found to be due to energy limitations of the runoff.

It was found that as selective erosion progressed, the availability of certain soil fractions may be changed, which limited the selection. For areas under cultivation, the effects of selective erosion were found to be accentuated by increases in the availability of the more valuable soil constituents as a result of plowing, cultivation, or rill development. Evidence was obtained in contradiction to the concept that slight or geological erosion is a beneficial soil forming process.
Capillary Intake Rate of Water and Soil Structure
Authors: Swartzendruber Dale , De Boodt M. F. , Kirkham Don
Published: July 2010

Rate of capillary absorption of water in soils was measured and compared with some other physical measurements as a possible index of structure. Disturbed and undisturbed samples were used. The disturbed samples were treated in two ways. Part were incubated in the presence of moisture and nutrient solution; part were mixed with a synthetic conditioner. After the disturbed samples were treated, they were air‐dried and screened to the size range 0.25–2.00 mm. Only this range of aggregate sizes was used in subsequent determinations. The undisturbed samples were cubes, I inch on an edge, sawed from larger, air‐dry clods, taken originally from moist, but not wet soil profiles, some in good structure, some in poor.

The structure measurements, which were used for the disturbed samples to adjudge the value of the capillary absorption rate as a structure index, were hydraulic conductivity and water stability of aggregates. For the undisturbed samples the comparison measurements were capillary porosity and aeration porosity.

For those disturbed samples which were incubated, and for those undisturbed samples which were taken in the A soil horizon, no significantly consistent relationships were found between the capillary absorption rate and the comparison measurements. For those disturbed samples treated with the synthetic soil conditioner, and for those cube samples taken below the A‐horizon, there were found significant or highly significant correlations with the comparison measurements. The action of organic matter on the wetting angle of the soil is believed to have caused the non‐significant results for the incubated samples and for the samples from the A‐horizon.

It is concluded that for soils containing variable amounts and kinds of organic matter, the capillary intake rate is not a reliable index of structure; but that for soils containing constant amounts and kinds of organic matter the capillary intake rate should be satisfactory.

An idealized capillary tube model of soil is presented as an aid in interpreting results. The model shows that with a constant wetting angle, the capillary absorption rate should be an index of structure. But the same model shows that hydraulic conductivity should be a better index than the capillary absorption rate. The last statement is in agreement with the experiments.

The existence of tables is reported for determining other statistical levels than the usual 1% or 5%. These tables are utilized to calculate specific levels for some of the data.
Multiple Tensiometer for Determining the Vertical Component of the Hydraulic Gradient in Soil
Authors: Richards L. A.
Published: July 2010

A description is given of an instrument for measuring the hydraulic head and hydraulic gradient of water in unsaturated field soil. Porous ceramic sections are mounted between plastic spacers to make a rod‐shaped instrument for insertion in a hole made by the Standard Veihmeyer soil sampling tube. Five porous sections with a vertical spacing of 10 cm, are thus arranged with individual connections to mercury manometers mounted at the top of the assembly.

During infiltration, after 44 cm of water had entered a deep, uniform, fine sandy loam, the downward hydraulic gradient averaged 1.3 in the 10–30 cm depth interval. This corresponds to a downward water‐moving force of 1.3 g. Six days later, a few hours after a 1‐cm rain, the average downward water‐moving force in the same depth interval was 5 g. Four days after the rain, there was a net upward water‐moving force of 36 g in the 10–20 cm depth interval, due to the influence of surface evaporation. A much higher value existed in the 0–10 cm layer because of the greater moisture gradient near the soil surface.

The term static zone is used in connection with the soil‐water system to designate the locus of points above which water movement is upward, and below which water movement is downward. A static zone passes downward through fallow soil following wetting. Over a four‐day period of warm dry weather following a heavy irrigation, the static zone passed downward at an average rate of 6 cm per day in a fallow fine sandy loam.
Seasonal Fluctuations in Soil Structure and Erodibility of Soil by Wind
Authors: Chepil W. S.
Published: July 2010

The objective of this investigation was to elucidate the effects of seasons on soil structure and erodibility by wind.

Little change in soil structure and erodibility occurred during a mild, dry winter near Lubbock, Tex., in 1952–53, but considerable change occurred during several consecutive winters in some areas of the Prairie soil zone of Kansas where the soils were usually moist.

Under moist conditions, frost action tended to break down the coarse water‐stable aggregates and at the same time tended to consolidate the finest fractions to an intermediate size, especially between 0.05 and 0.42 mm. in diameter. The probable mechanism of frost action on soil structure is described.

Secondary aggregates and clods tended to break down during the winter to a size erodible by wind (<0.84 mm. in diameter). Soil erodibility was in most cases much higher in spring than in fall. The greatest increase in erodibility occurred in finest textured soils, the least in coarsest. Seasonal fluctuations in soil structure and erodibility seldom exceeded 3 inches in depth. Below this depth, the structure and erodibility changed little from season to season.

During the summer there was usually an increase in the coarsest and the finest water‐stable soil fractions. It was concluded that the finest water‐stable fraction (<0.02 mm.) contains materials essential for the building of primary and secondary soil aggregates.
Separation of Organic Acids from Several Dormant and Incubated Ohio Soils
Authors: Schwartz S. M. , Varner J. E. , Martin W. P.
Published: July 2010

The objectives of this study were to determine the organic acid content of several of the Grey‐Brown Podzolic soils in Ohio and to study changes in the acids occurring as a result of short period aerobic incubatious of the soil materials at constant temperature and moisture.

The soil materials used in this investigation, Brookston silty clay loam, Crosby silt loam, Miami silt loam, and Wooster silt loam, were obtained from naturally wooded areas in the state.

A chromatographic column containing silica gel was employed for the separation of the organic acids. This procedure permitted the separation and quantitative estimation of the organic acids extracted with ether from the soil material. The identities of the organic acids were indicated by a comparison of their positions on an elution calibration chart with those of known pure organic acids. The chromatographically separated acids were not chemically characterized.

It was found that of the organic acids separated by this procedure, only two occurred in significant amounts, namely acetic and formic acids. In addition, very small quantities of other acids, including succinic and lactic acids and what are thought to be a group of high‐molecular weight fatty acids, were also separated. The latter probably resulted from alkali hydrolysis of the fats extracted from the soil materials.

A 1% glucose treatment of the several soil materials apparently did not appreciably change the organic acid make‐up either qualitatively or quantitatively. Preliminary data are presented concerning the effect of incubation on phosphorus solubility.