bluuebunny/crossref_metadata_2025 huggingface dataset:
Genomic characterization of large rearrangements of the LDLR gene in Czech patients with familial hypercholesterolemia
Authors: Goldmann Radan , Tichý Lukáš , Freiberger Tomáš , Zapletalová Petra , Letocha Ondřej , Soška Vladimír , Fajkus Jiří , Fajkusová Lenka
Published: July 2010

Background

Mutations in the LDLR gene are the most frequent cause of Familial hypercholesterolemia, an autosomal dominant disease characterised by elevated concentrations of LDL in blood plasma. In many populations, large genomic rearrangements account for approximately 10% of mutations in the LDLR gene.

Methods

DNA diagnostics of large genomic rearrangements was based on Multiple Ligation dependent Probe Amplification (MLPA). Subsequent analyses of deletion and duplication breakpoints were performed using long-range PCR, PCR, and DNA sequencing.

Results

In set of 1441 unrelated FH patients, large genomic rearrangements were found in 37 probands. Eight different types of rearrangements were detected, from them 6 types were novel, not described so far. In all rearrangements, we characterized their exact extent and breakpoint sequences.

Conclusions

Sequence analysis of deletion and duplication breakpoints indicates that intrachromatid non-allelic homologous recombination (NAHR) between Alu elements is involved in 6 events, while a non-homologous end joining (NHEJ) is implicated in 2 rearrangements. Our study thus describes for the first time NHEJ as a mechanism involved in genomic rearrangements in the LDLR gene.
The quality of preventive health care delivered to adults: results from a cross-sectional study in Southern Italy
Authors: Manuti Benedetto , Rizza Paolo , Bianco Aida , Nobile Carmelo GA , Pavia Maria
Published: July 2010

Background

It is assumed that providing clinical preventive services to patients can identify or detect early important causes of adult mortality. The aim of this study was to quantify access to preventive services in Southern Italy and to assess whether and how the provision of preventive care was influenced by any specific characteristics of patients.

Methods

In a cross-sectional study adults aged 18 years and over attending primary care physician (PCP) offices located in Southern Italy were interviewed from June through December 2007. Quality indicators of preventive health care developed from RAND's Quality Assessment Tools and Behavioral Risk Factor Surveillance System (BRFSS) were used. Multivariate analysis was performed to identify and to assess the role of patients' characteristics on delivery of clinical preventive services.

Results

A total of 1467 subjects participated in the study. Excepting blood pressure preventive check (delivered to 64.4% of eligible subjects) and influenza vaccination (recommended to 90.2% of elderly), the rates of delivery of clinical preventive services were low across all measures, particularly for screening and counseling on health habits. Rates for providing cancer screening tests at recommended times were 21.3% for colonoscopy, 51.5% for mammography and 52.4% for Pap smear. Statistical analysis showed clear disparities in the provision of clinical preventive services associated with age, gender, education level, perceived health status, current health conditions and primary care access measures.

Conclusions

There is overwhelming need to develop and implement effective interventions to improve delivery of routine clinical preventive services.
New method for selection of hydrogen peroxide adapted bifidobacteria cells using continuous culture and immobilized cell technology
Authors: Mozzetti Valeria , Grattepanche Franck , Moine Déborah , Berger Bernard , Rezzonico Enea , Meile Leo , Arigoni Fabrizio , Lacroix Christophe
Published: July 2010

Background

Oxidative stress can severely compromise viability of bifidobacteria. Exposure of Bifidobacterium cells to oxygen causes accumulation of reactive oxygen species, mainly hydrogen peroxide, leading to cell death. In this study, we tested the suitability of continuous culture under increasing selective pressure combined with immobilized cell technology for the selection of hydrogen peroxide adapted Bifidobacterium cells. Cells of B. longum NCC2705 were immobilized in gellan-xanthan gum gel beads and used to continuously ferment MRS medium containing increasing concentration of H2O2 from 0 to 130 ppm.

Results

At the beginning of the culture, high cell density of 1013 CFU per litre of reactor was tested. The continuous culture gradually adapted to increasing H2O2 concentrations. However, after increasing the H2O2 concentration to 130 ppm the OD of the culture decreased to 0. Full wash out was prevented by the immobilization of the cells in gel matrix. Hence after stopping the stress, it was possible to re-grow the cells that survived the highest lethal dose of H2O2 and to select two adapted colonies (HPR1 and HPR2) after plating of the culture effluent. In contrast to HPR1, HPR2 showed stable characteristics over at least 70 generations and exhibited also higher tolerance to O2 than non adapted wild type cells. Preliminary characterization of HPR2 was carried out by global genome expression profile analysis. Two genes coding for a protein with unknown function and possessing trans-membrane domains and an ABC-type transporter protein were overexpressed in HPR2 cells compared to wild type cells.

Conclusions

Our study showed that continuous culture with cell immobilization is a valid approach for selecting cells adapted to hydrogen peroxide. Elucidation of H2O2 adaptation mechanisms in HPR2 could be helpful to develop oxygen resistant bifidobacteria.
Induction of early Purkinje cell dendritic differentiation by thyroid hormone requires RORα
Authors: Boukhtouche Fatiha , Brugg Bernard , Wehrlé Rosine , Bois-Joyeux Brigitte , Danan Jean-Louis , Dusart Isabelle , Mariani Jean
Published: July 2010

Background

The active form (T3) of thyroid hormone (TH) controls critical aspects of cerebellar development, such as migration of postmitotic neurons and terminal dendritic differentiation of Purkinje cells. The effects of T3 on early dendritic differentiation are poorly understood.

Results

In this study, we have analyzed the influence of T3 on the progression of the early steps of Purkinje cell dendritic differentiation in postnatal day 0 organotypic cerebellar cultures. These steps include, successively, regression of immature neuritic processes, a stellate cell stage, and the extension of several long and mature perisomatic protrusions before the growth of the ultimate dendritic tree. We also studied the involvement of RORα, a nuclear receptor controlling early Purkinje cell dendritic differentiation. We show that T3 treatment leads to an accelerated progression of the early steps of dendritic differentiation in culture, together with an increased expression of RORα (mRNA and protein) in both Purkinje cells and interneurons. Finally, we show that T3 failed to promote early dendritic differentiation in staggerer RORα-deficient Purkinje cells.

Conclusions

Our results demonstrate that T3 action on the early Purkinje cell dendritic differentiation process is mediated by RORα.
Lifelong and lifewide learning from a biographical perspective: transformation and transition when coping with performance anxiety
Authors: Smilde Rineke
Published: July 2010

This article describes musicians' lifelong and lifewide learning as it was investigated through biographical research. Key developments in the professional lives of 32 musicians were examined, focusing on critical incidents and educational interventions in their life, educational and
career span. The main thread was the question of how these musicians learn. After analysis, three conceptual entities were established in the biographies, the first being musicians' artistic, generic and educational leadership; second, the interconnection between their varied learning styles;
and third, their need for an adaptive and responsive learning environment within a reflexive and reflective institutional culture. Two biographical examples of musicians suffering from performance anxiety are described, focusing on their leadership, learning styles and subsequent transformative
and transitional learning when developing coping strategies. The article concludes with directions for teaching and learning that can be extrapolated from the findings of biographical research.
Musowiki.net: notes on the creation of an online community music facility
Authors: Brown Hugh
Published: July 2010

This article describes the theoretical and practical justification for creating an online music community at www.musowiki.net. Through a discussion of the technological,
industrial and social aspects of an online environment, it provides a grounding body of theory and describes the process of designing the project. Consideration of some of the project's early outcomes reveals four principles for community building and offers examples of how they can be applied.
In conclusion, the article suggests that community music bodies and practitioners can enhance their activities both by participating in the Musowiki community and by adopting the four principles of community development.
Using forum theatre as university widening participation (WP) for social well-being agendas
Authors: Prior Ross W
Published: July 2010

This article traces a case study of how participatory theatre is used to make a positive impact on the widening participation (WP) agenda for one particular university in the United Kingdom. The WP agenda is a philosophical position taken by the UK government to restructure access to
higher education and is underpinned by notions of equality and diversity to improve social health and national well-being. The project titled H.E. for me ? is a joint venue between academic staff and students on a BA (Hons) Acting degree programme and several external partners. H.E.
for me ? aims to provide sixth formers with helpful information and insights into life at university. This innovative approach to dealing with WP uses the well-established convention of forum theatre in fulfilling objectives which give young people the opportunity to explore and interrogate
HE related issues. Accounts of the lead in period and the creative engagement phase of the project are offered, as well as the research outcomes. This article identifies the impact of, and the lessons emerging from, this pilot (intended to become an ongoing programme) and raises several pertinent
issues relating to the researchability of applied theatre.
Laboratory diagnostics in acute poisoning: critical overview
Authors: Rentsch Katharina M.
Published: July 2010

Laboratory diagnostics play an important role in the treatment of patients with acute poisoning. The classical clinical chemistry and hematology tests help initiate supportive treatment, and specialized methods enable elucidation of the poisons involved. In this context, two different analytical approaches are used: the direct quantification of a potentially involved compound or screening procedures looking either for a distinct drug class or a wide variety of different compounds. The most common tests are immunoassays, which have the advantage of being fast and highly automated. These assays are available for the substances which are often involved in intoxications. The other analytical technique which is widely used is hyphenated chromatography consisting of either high-performance liquid chromatography or gas chromatography as chromatographic systems and detection with a diode-array or mass spectrometer. Whereas gas chromatography mass spectrometry screening procedures have been known for a long time, liquid chromatography mass spectrometry screening methods are now developed by different research groups and still need to prove their reliability. In this review, the different analytical technologies and their application will be discussed.

Clin Chem Lab Med 2010;48:1381–7.
Release of Potassium from Nonexchangeable Forms from Size Fractions of Several Iowea Soils
Authors: Pratt P. F.
Published: July 2010

Surface samples of 13 Iowa soils were fractionated into six size fractions. K release from nonexchangeable forms from these size fractions was measured by an extraction for 10 minutes with boiling 1.0 N NHO3. The K release to HNO3 per unit weight was highest in the 0.2‐ to 2‐micron fraction for 12 of the 13 soils, was highest in the <0.2‐micron fraction for one soil, and decreased with increase in particle size in the silt fractions. For each of six size fractions the release per unit weight was correlated with release from the whole soil.

The calculated percentage distribution of K release among the size fractions suggested that the clay fractions contributed about 60% and the coarser fractions contributed about 40% of the K release from the whole soil.

For eight soils the lowest total K was in the <0.2‐micron fraction and the highest total K was in the 2‐ to 5‐micron fraction.

The percentage of the total K which was soluble in HNO3 was highest in the <0.2‐micron fraction and decreased with increase in particle size. The percentage solubility of K in the clay fraction was not related to the degree of weathering of the soils, but the percentage solubility in the silt fractions was closely correlated with degree of weathering.
The Effects of Fertilizer Applications on the Yields and Nodulation of Tropical Kudzu
Authors: Samuels George , Landrau Pablo
Published: July 2010

In view of the reported good growth of tropical kudzu, Pueraria phaseoloides javanica, in acid soils (pH 5.5 and below) and the use of nitrogen fertilizers to establish kudzu stand, this study was initiated to determine the effects of liming and nitrogen on yields and nodulation.

The tropical kudzu was grown in the greenhouse on Lares clay, an acid lateritic clay with a pH of 4.4. The treatments consisted of a control, nitrogen (1,200 pounds of ammonium sulfate), calcium (10,000 pounds of CaCO3), nitrogen plus calcium, and borax (30 pounds) plus calcium. All treatments received P2O5 and K2O at a rate of 100 pounds each per acre. The kudzu was harvested at a crop age of 3 months.

The use of nitrogen increased yields significantly over the control with no nitrogen, but the number of nodules per plant decreased very significantly from 59 nodules per plant to 10 nodules per plant. The lime treatment gave higher yields than the control, but not as high as the nitrogen treatment; the number of nodules per plant, however, was highest for the lime treatment. The use of lime and nitrogen in combination gave the highest yields, but the number of nodules per plant was reduced to the same as the treatment with nitrogen only. Lime and borax together gave high yields, parallel to the nitrogen treatment, but the number of nodules per plant was the lowest obtained for any treatment. The nitrogen content showed no statistically significant difference for any treatment.
Dominant Soils of the Redwood — Douglas‐fir Region of California
Authors: Storie R. Earl , Wieslander A. E.
Published: July 2010

More than three million acres of the upland area of the Redwood‐Douglas‐fir Region of California have been mapped and classified to obtain information for use in the management of forest, grazing, and watershed land, as well as basic data on the soils of this important area. In this survey the soils have been classified as to soil series and depth classes.

The dominant soil series are divided into six groups according to association with natural vegetation cover and productivity for timber and grass. Groups 1 and 2 are associated with conifer timber forests; groups 3 and 4 with grass and oak‐grass types; and groups 5 and 6 with chaparral. Group 1, the best for timber, includes soils of podzolic character, represented by such series as the Hugo and Josephine; Group 2, those of alkaline character, represented by the Cornutt and Dubakella series; Group 3, the best for grass, those classed as prairie soils, generally treeless and associated with perennial grasses and represented by the Los Osos and Kneeland series; Group 4, those classed as noncalcic brown, associated with annual grasses and open stands of oak, and represented by the Laughlin series; Group 5, lithosols of low site quality for grass and represented by the Los Gatos series; and Group 6, lithosols of very low site quality for grass and represented by the Maymen and Henneke series.

Data from profiles typical of the six groups of soils are presented showing soil characteristics, vegetational cover, and ratings of suitability for timber and for grass. These data point out that timber does best on medium textured deep (more than 4 feet to bedrock), permeable, well‐drained soils where the annual rainfall exceeds 40 inches; that grass, in contrast, does best on finer textured, less permeable, and less well‐drained — although shallower soils (between 2 and 3 feet deep) — which are typically less acid or more basic with depth; and that chaparral can grow on very shallow soils (less than 1 foot deep).
Evaluation of Certain Factors Involved in Increasing Manganese Availability with Sulfur
Authors: Garey C. L. , Barber S. A.
Published: July 2010

Manganese deficiency on certain Indiana soils may be corrected by adding sulfur. When elemental sulfur is added to the soil, three important changes take place: an oxidation‐reduction reaction, an increase in the sulfate ion concentration, and a pH change. The purpose of this investigation was to determine the importance of each of these factors in increasing manganese availability. Chemicals which would theoretically produce these three actions singly and in all possible combinations were added in equivalent amounts to a Maumee sandy loam soil having pH levels of 6.0, 6.5, and 7.5. This soil had previously shown severe manganese deficiency at the two higher pH levels. The chemicals used were elemental sulfur, sulfuric acid, hydrochloric acid, sodium thiosulfate, sugar, magnesium sulfate, and ammonium chloride. Soybeans were grown as the indicator crop.

Relationship between the yield and manganese content of the soybeans and the treatments were obtained under these conditions. The treatments including sulfur oxidation gave yields and manganese contents above that which could be attributed to pH change. Treatments causing a pH change benefited the crop in proportion to the pH change. The presence of sulfate alone gave no effect.
The Decomposition of Partridge Pea and its Influence on Nitrification
Authors: Colom Juan , McCalla T. M.
Published: July 2010

Comparative decomposition rates of alfalfa, wheat straw, and whole partridge pea, or its various plant parts taken separately, were determined by measuring weight losses during laboratory incubations. Effects of these plant materials on nitrification rates in soil were also determined.

The alfalfa lost the most weight by decomposition during a 32‐week period. The loss in weight of straw also exceeded that of the whole plant of partridge pea. The nitrification rate with partridge pea added was lower than that with untreated soil. Partridge pea leaves increased nitrification, but the pods or stalks decreased it.

The nitrate content of field plots previously grown to partridge pea was higher than that of plots without a legume, but not as high as in plots previously in sweet clover.
Response of Potatoes to Rate and Placement of Nitrogen in Connecticut, 1948–1950
Authors: Hawkins Arthur , Brown B. A.
Published: July 2010

Since the use of new more efficient insecticides and fungicides permits potato vines to live longer, it appeared necessary to reevaluate the response of potatoes to rate and placement of nitrogen fertilization. Such experiments were conducted on growers' fields in the Connecticut River Valley 1948–1950, located on fine sandy loam soils which had been cropped frequently to potatoes, the most common situation in Connecticut. These soils contained from 2 to 3% organic matter and had pH values of 4.8–5.5.

Plots four rows wide by either 40 or 50 feet long were replicated six times in a Latin Square design. The same amount of phosphorus and potash was applied in the row in each case, namely, 180 pounds per acre. The nitrogen rates ranged from 90 to 180 pounds per acre in 1948 and 1949, and from 120 to 210 pounds in 1950.

The results indicate that with the use of the best insect and disease control methods for potatoes, grown on land planted frequently to potatoes, increased yields can be obtained with increasing amounts of nitrogen up to about 150 to 180 pounds per acre in a favorable season. The use of injurious fungicides and/or inadequate insect control resulted in little or no response to more than 90 to 120 pounds of nitrogen per acre especially in years of low rainfall.

During the favorable season of 1950 at locations where the moisture holding capacity of the soil was favorable or where irrigation was used on a droughty soil during dry periods, increased yields of potatoes were obtained with 180 and in some instances, with 210 pounds of nitrogen per acre over lesser amounts, on soils low in available nitrogen.

There was no advantage in yields from broadcasting part of the nitrogen either in the form of castor pomace or sulfate of ammonia previous to planting, or sidedressing with ammonium nitrate as compared with putting all the nitrogen in the row, side band placement, at planting time.

The study showed the availability to potatoes of applications of ammonium nitrate to furnish 50 to 90 pounds of nitrogen applied when the plants were 6 to 10 inches high. This is a less expeusive method of supplying nitrogen for potatoes.
Decomposition of Bentonite as Affected by H, Ca, Mg, and Dry Grinding
Authors: Perkins Alfred T. , Dragsdorf R. D.
Published: July 2010

The objective of the work is to show data on the effect of close contact, during grinding, of several cations, on the decomposition of bentonite. H, Ca, and Mg were chosen to saturate the bentonite and the clay was dry ground for 36 weeks in a ball mill. The decomposition products were examined by studying chemical composition, chemical reactions, solubility, X‐rays, etc. The data indicated that the presence of Mg as compared to H or Ca caused a more rapid decomposition of the bentonite. In many cases a similarity of structure of the ground bentonite persisted as shown by X‐ray patterns in spite of great differences in base exchange capacity and solubility and other chemical characteristics.
The Nodulation Status of Trifolium ambiguum
Authors: Parker Don T. , Allen O. N.
Published: July 2010

Trifolium ambiguum (kura, Pellett or honey clover) is a potentially important clover species, although nodule occurrence on its roots is rare, and evidence is lacking that it benefits from any association with rhizobia. The objective of this study was to ascertain the response patterns of this clover and 7 allied species to 35 diverse strains of Rhizobium trifolii.

Diverse categories of plant response were defined in reciprocal inoculation tests. T. hybridum (alsike) and T. repens f. giganteum (Ladino) were benefited by 31 strains. Twenty‐two strains brought about ineffective responses on T. incarnatum (crimson) and T. subterraneum (sub). T. ambiguum was only sparsely nodulated and not benefited by any of the strains. The rhizobia isolated from T. ambiguum brought about typical ranges of plant response of the seven other clover species tested. T. procumbens (low hop) and T. repens f. giganteum (Ladino) were benefited by all of the strains from T. ambiguum. Only three of the Pellett clover strains were effective on T. incarnatum and T. subterraneum. Nodules were not formed on T. ambiguum by any of 52 rhizobial strains from 26 ecologically related species contained in 23 leguminous genera.

Probable explanations for the sparse nodulation and lack of effective response by T. ambiguum to rhizobia are suggested.
Removal of Coatings from Soil Particles for Petrographic Analysis
Authors: Matelski Roy P.
Published: July 2010

Detergents and builders have been used successfully to remove the organic and inorganic coatings from soil particles prior to petrographic analysis. Essentially, the procedure consists of triturating the soil sample in a liter beaker with a cationic detergent, dilution and decantation of the clay and fine silt, followed by several triturations with an anionic detergent and builders, dilution and decantation of the clay and fine silt.

Soils representative of the Prairie, Chernozem, Chestnut, Reddish Chestnut, Gray‐Brown Podzolic, Podzol, Red‐Yellow Podzolic, Planosol, Grumusol, Humic Glei and Ground‐Water Podzol were investigated. All coarse silt and sand particles after treatment were free of organic matter, iron oxide and other coatings. No hydrogen peroxide was needed to remove the organic matter from the soil.

The effect of the reagents of this and of Jeffries' nascent hydrogen procedure on apatite, hornblende and albite are shown on photomicrographs. Considerably less breakdown of the minerals is evident with the proposed method. In general, the suggested new procedure is more rapid, simple and less destructive than the currently used soil cleaning methods.
Suggested Terminology for Describing Soils as Three‐dimensional Bodies
Authors: Hole Francis D.
Published: July 2010

Many papers on soil classification emphasize soil characteristics as revealed in the relatively narrow vertical cross‐sections of soil called soil profiles. The assumption is generally made that the soils, from which the profile descriptions are taken, extend laterally far enough to constitute segments of landscapes. But terminology has not been developed sufficiently to permit both horizontal and vertical aspects to be considered in the description and classification of soils. Some terms are suggested which have been found useful in describing Wisconsin soils as three‐dimensional bodies.
The Effects of Fungicides, Insecticides, Herbicides, and Fertilizer Salts on the Respiration of Root Tips of Tree Seedlings
Authors: Voigt G. K.
Published: July 2010

The effect of various eradicants and fertilizers used in nursery practice on the oxygen uptake of excised root tips of seedlings of jack pine, red pine, white pine, and black locust seedlings was investigated using manometric techniques. The compounds studied included calomel, spergon, thiosan, chlordane, Stoddard oil, and common fertilizer salts applied at ordinary rates. In the first phase of the study the root tips were placed directly into solutions or suspensions of various compounds and their rate of oxygen uptake determined. The second phase was concerned with the respiration of root tips of seedlings grown in cultures treated with the chemicals. The measurements show that some of the compounds applied to nursery soils are inhibitory to the metabolism of roots of young seedlings. The results also indicate that manometric methods of analysis provide a useful tool for the evaluation of the effect of various chemical compounds used in current nursery practice.
Physical and Chemical Characteristics of the Major Types of Forest Humus Found in the United States and Canada
Authors: Mader Donald L.
Published: July 2010

In order to broaden the existing classification of forest humus, a systematic analytical study was undertaken as a co‐operative project including specialists from forestry and agricultural colleges, U. S. forest experiment stations, and private forestry enterprises. To date the project received support of forty collaborators from forty‐one states and two provinces of Canada. All humus samples forwarded were subjected to the following analyses: weight of forest litter per acre, bulk density of F plus H and A1 horizons, their texture, reaction, lime deficit, exchange capacity, exchangeable bases and degree of base saturation, specific conductance, contents of total nitrogen and carbon, C/N ratio, and catalytic capacity.

Classification of humus samples was made in accordance with suggestions of collaborators or on the basis of the proposals made in the course of the last five years. Results of analyses suggest that humus layers of different morphological makeup maintain certain distinguishing physical and chemical characteristics over an enormously wide territory.
Soil Moisture Tension as a Measure of Water Removal Rate from Soil and Its Relation to Weather Factors
Authors: Ashcroft Gaylen , Taylor Sterling A.
Published: July 2010

The moisture tension in the soil at any specified time can be expressed as a function of depth. When it is possible to express the moisture content as a function of tension, it is then possible to express moisture content as a function of depth in the soil. The equation relating moisture content and depth is integrated over the depth of the root zone to give the total quantity of water in the soil. The quantity of water in the soil at any time is then subtracted from the amount which can be held without excessive deep percolation occurring. The difference represents the amount of water that can be retained by the soil from an irrigation. This amount should be increased by the runoff, evaporation, and other expected losses, in order to determine the quantity of water that should be applied at an irrigation.

Moisture tension has been measured as a function of depth by using both resistance blocks calibrated in terms of tension and tensiometers. The relationship between moisture tension and moisture content has been expressed mathematically and the quantity of irrigation water required has been applied. Good results have been obtained.

Indications have been found that the amount of water required at an irrigation may possibly be calculated from climate as indicated by weather records during the irrigation interval. It does not seem likely, however, that the irrigation interval can be established for all crops on all soils in any one area from weather data alone.
A Diffusion‐Equilibrium Method for Obtaining Soil Gases under Field Conditions
Authors: Taylor George S. , Abrahams J. H.
Published: July 2010

A soil gas sample obtained by mass flow of gases may not be representative of the point sampled because of mixing with gases from other soil depths or from the atmosphere. The authors have investigated a method which eliminates this error and which is based on the diffusion of gases between a point in the soil to a collection chamber via a tube tightly fitted in the soil.

A physical analysis and laboratory tests were made to determine the time required for the collected gas to be representative of the soil atmosphere at any depth. For all conditions, this time depends on initial differences between the partial pressure of a gas in the collection chamber and in the soil. When the percentage of water‐free pores in soil is approximately 20 or greater, the time is strongly dependent on the volume of the collection chamber and on the diameter and length of the tube connecting the chamber to a point in the soil. For porosities between 0–15%, the effect of reduced diffusion rates in soil becomes significant and increases the time. Equations are given for making these calculations.

An evaluation was also made of the condition in which (1) approximate equilibrium had been previously established between partial pressures in the chamber and in the soil, and (2) partial pressures in the soil were changing due to release or absorption of a gas. It was shown that the pressure of a gas in the chamber will not differ from its partial pressure in the soil by more than 0.5% unless concentration changes in the soil exceed 15% by volume per day.

Oxygen analyses are shown for 2‐years field results. The average coefficient of variation of oxygen concentration was a low value of 3% but was strongly dependent on soil moisture content. Some comparisons of soil oxygen concentrations obtained by pumping and by the diffusion‐equilibrium method showed that the former method gave higher values.
Some Greenhouse Studies of Cation Interactions in Ladino Clover Using Split Root Techniques
Authors: Nelson L. E. , Brady N. C.
Published: July 2010

The object of this study was to supply cations to Ladino clover without adding them to the soil in which the plant was growing so that the interactions of the ions in the plant could be separated from their chemical reactions in the soil.

Two techniques are described; the basic principle common to each technique was the isolation of part of the root system of the plant in a sand culture to which the desired nutrient ions could be added.

Using the “Three Compartment” technique, the potassium content of Ladino clover was increased by adding potassium salts to the isolated roots. The increase in potassium content was accompanied by a decrease in the calcium content.

Using the “Horizontally Divided Root Environment” technique with Ladino clover, reciprocal relationships in the cation content of the leaves and petioles occurred between sodium and potassium, potassium and calcium, and calcium and potassium. Calcium potassium, and sodium treatments were equally effective in decreasing the magnesium and manganese contents.
Solonetz Soils of Eastern South Dakota: Their Properties and Genesis
Authors: Westin F. C.
Published: July 2010

Two aspects of the genesis of Solonetz soils were considered in this study: the specific environment of solonization, and the changes in soil constituents and in soil volume which take place as a result of solonization.

Field and laboratory studies were made on a Solonetz and a zonal soil from the James Basin. Heavy mineral data related the soil profiles to their parent materials and provided an independent reference for judging volume changes due to soil formation.

Both the Solonetz and Chernozem soil developed from parent material which is saline and sodium‐rich. The solonetz soil developed in an environment having alternate periods of ponding and desiccation; the Chernozem in an environment of uninterrupted good drainage.

A unit volume of the parent material of both the Solonetz and Chernozem soils contains a greater weight of most soil constituents than is present in the volume of B horizon to which it gives rise.

A reduction in volume of the parent material accompanies solonization so that depressions containing Solonetz soils would continue to deepen. Rather than developing into zonal soils, it is believed that Solods remain depressional soils in their moisture relations and morphology.
Estimating Summer Evapo‐Transpiration Losses in a Pennsylvania Scrub Oak Forest
Authors: Bethlahmy Nedavia
Published: July 2010

Fiberglas soil‐moisture units were placed to a depth of 2 feet in the different soils underlying a scrub oak forest in Pennsylvania. Successive daily readings on these units indicated the amount of water lost or gained in the horizon.

To determine evapo‐transpiration losses, daily soil‐moisture losses were analyzed for periods during the summer months when the soil was at or below field capacity. These losses were then related to several factors. Atmospheric saturation deficit was the only climatic element that was statistically related to evapotranspiration losses. Other climatic elements studied (air temperature and wind velocity) bore no relation to the soil moisture losses. In addition, soil moisture content and length of time elapsed since a storm had no relation to these losses. Further analysis revealed that evapo‐transpiration losses start at a minimum saturation deficit of approximately 0.020 inches of mercury, and that the value of the saturation deficit regression coefficient is directly related to the total sand content in the soil profile.

Thus, for areas with vegetation similar to scrub oak, it may be possible to determine the evapo‐transpiration regression equation by making a mechanical analysis of the underlying soil. Since this work was done on a watershed in which an attempt is made to balance the water economy, it was possible to check the calculated evapo‐transpiration losses. The check was favorable.
Effect of Prewetting and Incubation of Soil on Aggregate Analysis
Authors: Evans D. D.
Published: July 2010

Data are presented for the water stability of air‐dry, stored, field soil aggregates as influenced by prewetting treatments made respectively 24 hours and 5 minutes prior to wet sieve analysis. Wetting the samples to moisture equivalent 24 hours prior to wet sieving, and then incubation, increased the water stability of samples significantly over samples wetted to the same moisture percentage 5 minutes before wet sieving. The prewetting treatments, when applied to soils from plots in two crop rotation experiments, placed the soils from the various rotations in different order of water stability, depending on whether the 24‐hour or 5‐minute prewetting period was used. As an extreme example, the 24‐hour prewetting period, resulted in the highest water stability for soil from a corn‐oats rotation; whereas the soil from this same rotation, when prewetted for only a 5‐minute interval, resulted in the lowest water stability, of the several rotations.

The cause of the increase in aggregation by the two methods was investigated by superimposing a number of additional treatments on the basic wetting treatments. It was found that microbial activity during the 24‐hour wet incubation period contributed very little to the increase. The increase was attributed to the hydration of the clay particles with a resulting removal of planes of weakness in the dried aggregates. It is suggested in field studies, that a prewetting treatment be chosen which reinstates the soil to a structural condition that most likely exists, at a time, when the particular physical property of interest of the soils is of concern.
The Effect of Mineral Nutrition on the Expression of Potato Leaf Roll Virus Symptoms
Authors: Hoveland C. S. , Berger K. C. , Darling H. M.
Published: July 2010

Some mineral deficiency symptoms and those of the leaf roll virus have frequently been confused. The similarity between mineral deficiencies and leaf roll symptoms suggests that the effect of the virus might be influenced by the nutrition of its host. A study of certain mineral relationships between healthy and diseased leaf roll plants in the Chippewa variety was therefore undertaken.

In greenhouse and field experiments it was found that phosphorus deficiency produced symptoms ranging from slight to severe rolling of the leaves and from light to heavy pigment formation as the amount of phosphorus decreased. Symptoms of extreme phosphorus deficiency in non‐virus plants were similar to those produced by the virus except that more pigmentation occurred in the phosphorus deficiency symptoms. Severe nitrogen and slight phosphorus deficiencies caused only a moderate increase in the intensity of leaf roll symptoms while calcium, potassium, magnesium and sulfur had little or no effect. Leaf roll symptoms tended to be masked with adequate balanced nutrition.

Analyses of leaf tissues taken from plants grown in the greenhouse and field showed in general that phosphorus, calcium, and magnesium contents were appreciably reduced in plants having leaf roll. The nitrogen and potassium contents apparently were not influenced by the virus.

Dry weights of diseased plants were generally less than those of non‐virus plants. The results indicate that this might have been caused by the virus interfering with the uptake of phosphorus, calcium, and magnesium.
Fertilizer Experiments with Field Corn on Everglades Peaty Muck Soil
Authors: Forsee W. T. , Green V. E. , Webster R. H.
Published: July 2010

Fertility experiments have been conducted with field corn on Everglades Peaty Muck soils in order to determine the required fertilizer program with respect to P2O5 and K2O.

Four experiments have been conducted involving potash, phosphate experiments laid out in randomized block designs and nitrogen, potash, phosphate experiments laid out in 3 × 3 × 3 factorial designs. Soils tests were used to determine the P2O5 and K2O levels in the soil and tissue tests were conducted to measure the uptake of these nutrients from the soils. These data have been correlated with yields in order to furnish the necessary information on which to base fertilizer recommendations from the results of soil or tissue tests.

The corn showed yield responses to increasing levels of potash in the soil up to values as high as approximately 70 pounds potassium per acre as determined by the soil tests. The yields ranged from 26 bushels per acre at the lowest K2O levels to 63 bushels at the level of maximum response which produced plants that gave stem tissue tests averaging approximately 5.00% potassium, moisture free basis. Potash deficient corn gave tissue tests as low as 2.72% potassium.

Yield responses to applications of superphosphate were obtained up to levels of approximately 8 pounds per acre of water soluble phosphorus as determined by soil tests. Plants showing no phosphate deficiencies gave stem tissue test values in excess of 0.10% of the element, moisture free basis. The assimilation of P2O5 was apparently reduced by higher levels of K2O in the soil and that of K2O was reduced slightly by higher levels of P2O5.

The experiments indicate that fertilizer recommendations for field corn on organic soils may be intelligently made on the basis of soil tests which have been previously correlated with growth and yield response.
Cationic Activities as Indexes for Characterizing Five Arkansas Soils Occurring in the Southern Region
Authors: McLean E. O. , Baker F. E.
Published: July 2010

Five soils and 3 extracted colloidal materials were characterized by means of the clay membrane electrode technique for measuring ionic interactions. The study dealt with Lakeland loamy fine sand, Ruston sandy loam, Crowley silt loam, Houston clay, Sharkey clay soils and the <.2 µ clay, the <25 µ clay, and the crude humic acid fractions extracted from the Sharkey clay soil.

The characteristic curves resulting from the plotting of the fractions of K active at various K‐Ca saturations of the soils and extracted materials were prepared. Comparison of these curves with those of the individual clay minerals made possible the characterization of the soils and the extracts with respect to which clay minerals appeared to predominate in them.

The results indicate that kaolinite clay dominates the regulation of cationic interactions in the Lakeland, Ruston,a nd Crowley soils. Beidellite appears to predominate in the Houston and Sharkey soils. Montmorillonite seems to play the major role in the < 25 µ clay from the Sharkey, but the beidellite evidently masks the effect of the montmorillonite in the < .2 µ clay and in the whole soil. The crude humic acid from the Sharkey gave no evidence of any appreciable effect upon the cationic interactions of the whole soil.
Effect of Lime on the Availability of Phosphorus in Soils of High to Low Sesquioxide Content
Authors: Robertson W. K. , Neller J. R. , Bartlett F. D.
Published: July 2010

The effect of rates of lime and phosphorus were tested on three virgin and three cropped Florida soils over a wide range of sesquioxide and phosphorus contents.

The experiment was set up in the greenhouse. Lime was applied to get a wide range of pH levels. Oat and corn yield data and the percent recovery of applied phosphorus tagged with P32 were the criterion of response.

Liming soils relatively low in residual phosphorus increased the availability of applied phosphorus up to pH 6 to 6.5 when the sesquioxides were high but had no effect where the sesquioxides were low. Liming these soils above 6 to 6.5 caused the percentage of phosphorus in the plant from the fertilizer to level off or decline, probably due to the formation of relatively unavailable tricalcium phosphate. Liming soils high in residual phosphorus reduced the availability of fertilizer phosphate regardless of the sesquioxide content. Uptake of phosphorus from currently applied superphosphate was highest from the soils high in sesquioxide content irrespective of rate of liming.
The Characteristics of Some Soils on Tills of Cary and Mankato Age in Michigan
Authors: Allen B. L. , Whiteside E. P.
Published: July 2010

Field and laboratory studies were made of the well drained soils and the associated loamy tills of the Cary and Mankato substages of the Wisconsin drift in Sanilac County, Mich.

The soils on the Cary till are deeper, more acid, and more clearly differentiated into horizons than those on the Mankato till. The mean carbonate content and depth of leaching of the Mankato till are 31.4% and 20 inches, respectively. The mean carbonate content and depth of leaching on the Cary till are 22.4% and 29 inches, respectively. The soil profile studied on the Mankato till is more permeable in all horizons than the profile on the Cary till. The C horizons — i.e., the glacial tills — are the most impermeable parts of both profiles.

Calculations using these data and assuming 11,000 years as the length of post‐Mankato time indicate that the duration of the Cary‐Mankato interglacial stage was 1,100 to 5,500 years. Further work is needed on this point.
Aspects of Structure that Affect Germination in a Silt Loam Soil
Authors: Slater C. S. , Rodriguez Alvaro
Published: July 2010

Stability of aggregates to slaking, as determined by wetsieve analyses, failed to account for differences in structural quality between naturally stable and chemically stabilized Christiana silt loam. The treated and untreated soils were equally resistant to slaking, but permeability and seed germination were better in the treated soil. These differences were related to differences in the consistency of the moist aggregates.
Observations on Factors Influencing the Evaporation of Soil Moisture
Authors: Hide J. C.
Published: July 2010

Important variables which influence the rate of evaporation of soil moisture are (1) the vapor pressure difference between the layer from which water is evaporating and that of the turbulent atmosphere and (2) the resistance to vapor flow of the intervening layer. The vapor pressure difference is associated with the temperature of the layer from which evaporation is taking place and the temperature and relative humidity (vapor pressure) of the turbulent air. While capillarity moves water fast enough to keep the surface moist, the principal resistance to vapor flow is caused by the thin layer of nonturbulent air adjacent to the surface. Resistance increases rapidly as the surface dries so that water vapor moves through a thickening layer of dry soil. Adsorption of moisture by the dry layer and re‐evaporation associated with the diurnal temperature cycle complicate the process. Mositure movement in the upper layers of soil during the evaporation cycle was studied by periodic weighing of soil in vertically stacked porous bottomed containers and through the use of tensiometers. The data show the highly dynamic nature of the moisture regime in the surface layers of soil associated with diurnal temperature changes and the evaporation cycle.