WorldWideScience

Sample records for factors including soil

  1. Soil-structure interaction including nonlinear soil

    OpenAIRE

    Gicev, Vlado

    2008-01-01

    There are two types of models of soil-structure system depending upon the rigidity of foundation: models with rigid and models with flexible foundation. Main features of the soil-structure interaction phenomenon: -wave scattering, -radiation damping, -reduction of the system frequencies. In this presentation, the influence of interaction on the development of nonlinear zones in the soil is studied.

  2. Soil Forming Factors

    Science.gov (United States)

    It! What is Soil? Chip Off the Old Block Soil Forming Factors Matters of Life and Death Underneath It All Wise Choices A World of Soils Soil Forming Factors 2 A Top to Bottom Guide 3 Making a Soil Monolith 4 Soil Orders 5 State Soil Monoliths 6 Where in the Soil World Are You? >> A Top to

  3. Perinatal risk factors including malformation

    International Nuclear Information System (INIS)

    Brachner, A.; Grosche, B.

    1991-10-01

    The study gives a survey of the factors most frequently mentioned in the literature as factors likely to adversely affect a pregnancy. One essential aspect is the discussion of those factors that can be counted among the causes of malformations, as among others, prenatal radiation exposure. The study prepared within the framework of the research project 'Radiobiological environmental monitoring in Bavaria' is intended to serve as a basis for a retrospective and prospective evaluation of infant mortality, perinatal conditions and occurrence of malformations in Bavaria, with the principal idea of drawing up an environment - related health survey. The study therefore, in addition to ionizing radiation also takes into account other detectable risks within the ecologic context, as e.g. industrial installations, refuse incineration plants or waste dumps, or urbanity. (orig./MG) [de

  4. Reliability evaluation of containments including soil-structure interaction

    International Nuclear Information System (INIS)

    Pires, J.; Hwang, H.; Reich, M.

    1985-12-01

    Soil-structure interaction effects on the reliability assessment of containment structures are examined. The probability-based method for reliability evaluation of nuclear structures developed at Brookhaven National Laboratory is extended to include soil-structure interaction effects. In this method, reliability of structures is expressed in terms of limit state probabilities. Furthermore, random vibration theory is utilized to calculate limit state probabilities under random seismic loads. Earthquake ground motion is modeled by a segment of a zero-mean, stationary, filtered Gaussian white noise random process, represented by its power spectrum. All possible seismic hazards at a site, represented by a hazard curve, are also included in the analysis. The soil-foundation system is represented by a rigid surface foundation on an elastic halfspace. Random and other uncertainties in the strength properties of the structure, in the stiffness and internal damping of the soil, are also included in the analysis. Finally, a realistic reinforced concrete containment is analyzed to demonstrate the application of the method. For this containment, the soil-structure interaction effects on; (1) limit state probabilities, (2) structural fragility curves, (3) floor response spectra with probabilistic content, and (4) correlation coefficients for total acceleration response at specified structural locations, are examined in detail. 25 refs., 21 figs., 12 tabs

  5. Dynamic Analysis of Wind Turbines Including Soil-Structure Interaction

    DEFF Research Database (Denmark)

    Harte, M.; Basu, B.; Nielsen, Søren R.K.

    2012-01-01

    This paper investigates the along-wind forced vibration response of an onshore wind turbine. The study includes the dynamic interaction effects between the foundation and the underlying soil, as softer soils can influence the dynamic response of wind turbines. A Multi-Degree-of-Freedom (MDOF......) horizontal axes onshore wind turbine model is developed for dynamic analysis using an Euler–Lagrangian approach. The model is comprised of a rotor blade system, a nacelle and a flexible tower connected to a foundation system using a substructuring approach. The rotor blade system consists of three rotating...... for displacement of the turbine system are obtained and the modal frequencies of the combined turbine-foundation system are estimated. Simulations are presented for the MDOF turbine structure subjected to wind loading for different soil stiffness conditions. Steady state and turbulent wind loading, developed using...

  6. [Interrelationships between soil fauna and soil environmental factors in China: research advance].

    Science.gov (United States)

    Wang, Yi; Wei, Wei; Yang, Xing-zhong; Chen, Li-ding; Yang, Lei

    2010-09-01

    Soil fauna has close relations with various environmental factors in soil ecosystem. To explore the interrelationships between soil fauna and soil environmental factors is of vital importance to deep understand the dynamics of soil ecosystem and to assess the functioning of the ecosystem. The environmental factors affecting soil fauna can be classified as soil properties and soil external environment. The former contains soil basic physical and chemical properties, soil moisture, and soil pollution. The latter includes vegetation, land use type, landform, and climate, etc. From these aspects, this paper summarized the published literatures in China on the interrelationships between soil fauna and soil environmental factors. It was considered that several problems were existed in related studies, e.g., fewer researches were made in integrating soil fauna's bio-indicator function, research methods were needed to be improved, and the studies on the multi-environmental factors and their large scale spatial-temporal variability were in deficiency. Corresponding suggestions were proposed, i.e., more work should be done according to the practical needs, advanced experiences from abroad should be referenced, and comprehensive studies on multi-environmental factors and long-term monitoring should be conducted on large scale areas.

  7. Factors impacting the electro conductivity variations of clayey soils

    International Nuclear Information System (INIS)

    Ouhadi, V. R.; Goodarzi, A. R.

    2007-01-01

    The variation of pore fluid properties in soil has a major effect on soil behaviour. This effect is a function of pore fluid properties and soil mineralogy. Such variation usually happens in the reservoirs of dams or in some geotechnical projects. The electro conductivity measurement is a simple method to monitor any variation in the pore fluid of soils. electro conductivity is the ability of a material to transmit (conduct) an electrical current. This paper focuses attention on the effect of soil-pore fluid interaction on the electro conductivity of clayey soils. A set of physico-chemical experiments are performed and the role of different factors including soil pH, soil mineralogy, soil: water ratio, cation and anion effects are investigated. The results of this study indicate that for soil that has a relatively low CEC, the anion type is an important factor, while the cation type does not noticeably affect the electro conductivity of the soil-solution. However, for such soil, an electrolyte property, i.e. its solubility, is much more effective than the CEC of the soil. In addition, it was observed that in the presence of neutral salts such as pore fluid, the pH of the soil-solution decreases causing an increase in the electro conductivity of the soil sample

  8. Experimental Study of Factors Affecting Soil Erodibility

    Science.gov (United States)

    Larionov, G. A.; Bushueva, O. G.; Gorobets, A. V.; Dobrovolskaya, N. G.; Kiryukhina, Z. P.; Krasnov, S. F.; Litvin, L. F.; Maksimova, I. A.; Sudnitsyn, I. I.

    2018-03-01

    The effect of different factors and preparation conditions of monofraction samples from the arable horizon of leached chernozem on soil erodibility and its relationship with soil tensile strength (STS) has been studied. The exposure of samples at 38°C reduces their erodibility by two orders of magnitude. The drying of samples, on the contrary, increases their erodibility. It has been shown that erodibility decreases during the experiment. It has been found that the inoculation of soil with yeast cultures ( Naganishia albida, Lipomyces tetrasporus) reliably increases the STS value in 1.5-1.9 times. The sterile soil is eroded more intensively than the unsterile soil: at 4.9 and 0.3 g/(m2 s), respectively. The drying of soil followed by wetting to the initial water content (30%) has no significant effect on the STS value in almost all experimental treatments.

  9. Soil sealing degree as factor influencing urban soil contamination with polycyclic aromatic hydrocarbons (PAHs

    Directory of Open Access Journals (Sweden)

    Mendyk Łukasz

    2016-03-01

    Full Text Available The objective of the study was to determine role of soil sealing degree as the factor influencing soil contamination with polycyclic aromatic hydrocarbons (PAHs. The study area included four sampling sites located within the administrative boundaries of the Toruń city, Poland. Sampling procedure involved preparing soil pits representing three examples of soil sealing at each site: non-sealed soil as a control one (I and two degrees of soil sealing: semi-pervious surface (II and totally impervious surface (III. Together with basic properties defined with standard procedures (particle size distribution, pH, LOI, content of carbonates content of selected PAHs was determined by dichloromethane extraction using gas chromatography with mass spectrometric detection (GC-MS. Obtained results show that urban soils in the city of Toruń are contaminated with polycyclic aromatic hydrocarbons. Soil sealing degree has a strong influence on the soil contamination with polycyclic aromatic hydrocarbons. Totally sealed soils are better preserved from atmospheric pollution including PAHs. Combustion of grass/wood/coal was the main source of determined PAHs content in examined soils.

  10. Variability of soil-to-crop transfer factor

    International Nuclear Information System (INIS)

    Uchida, Shigeo; Kamada, Hiroshi; Yokosuka, Setsuko; Ohmomo, Yoichiro

    1987-01-01

    Many European countries have nuclear facilities in inland areas, where extremely low level radioactive waste liquid is discharged to rivers. In those nations, therefore, many studies have been made oncerning the transfer of radioisotopes into plants. In Japan, greater attention has been attracted to such radioisotope transfer into plants and then into human bodies. Thus the present report reviews various studies on this issue. The key parameter for this process is the transfer factor (also called concentration factor, coefficient or ratio). The factor largely depends on various other factors including the characteristics of different nuclides, properties of soil (pH, oxidation-reduction potential, grain size distribution, contents of clay minerals, contents of organic matters, water content, etc.), characteristics of crops and cultivation conditions. It has been reported that I is absorbed by plants more rapidly than IO 3 . Of the various soil parameters, the pH of soil has the greatest effect on the transfer factor. Soil is mostly alkaline in Europe and America while acid soil account for a great part in Japan, suggesting that the transfer factor would be greater in Japan. The total potassium content in soil has the second largest effect on the factor. Radioactive iodine has shown to be transferred into soy beans and spinach 30 times more rapidly than into fruit vegetables. The oxidation-reduction potential also has a significant influence on the transfer factor. (Nogami, K.)

  11. SOIL FORMATION BY ECOLOGICAL FACTORS: CRITICAL REVIEW

    OpenAIRE

    Saeed Zeraat Kar; Aydin Berenjian

    2013-01-01

    Regolith is the term we give parent material that has been weathered. The regolith consists of weathered bedrock near the surface including the soil layer. In the Iranian soil layer we will find: decayed parent materials, decaying plant material, decaying animal matter (manure) along with vegetation. Results of the present study show us that methods stimulating natural fertility in Iran includes composting-adds humus layer, drip irrigation-balances illuviation and eluviation in arid regions, ...

  12. PRINCIPAL COMPONENT ANALYSIS OF FACTORS DETERMINING PHOSPHATE ROCK DISSOLUTION ON ACID SOILS

    Directory of Open Access Journals (Sweden)

    Yusdar Hilman

    2016-10-01

    Full Text Available Many of the agricultural soils in Indonesia are acidic and low in both total and available phosphorus which severely limits their potential for crops production. These problems can be corrected by application of chemical fertilizers. However, these fertilizers are expensive, and cheaper alternatives such as phosphate rock (PR have been considered. Several soil factors may influence the dissolution of PR in soils, including both chemical and physical properties. The study aimed to identify PR dissolution factors and evaluate their relative magnitude. The experiment was conducted in Soil Chemical Laboratory, Universiti Putra Malaysia and Indonesian Center for Agricultural Land Resources Research and Development from January to April 2002. The principal component analysis (PCA was used to characterize acid soils in an incubation system into a number of factors that may affect PR dissolution. Three major factors selected were soil texture, soil acidity, and fertilization. Using the scores of individual factors as independent variables, stepwise regression analysis was performed to derive a PR dissolution function. The factors influencing PR dissolution in order of importance were soil texture, soil acidity, then fertilization. Soil texture factors including clay content and organic C, and soil acidity factor such as P retention capacity interacted positively with P dissolution and promoted PR dissolution effectively. Soil texture factors, such as sand and silt content, soil acidity factors such as pH, and exchangeable Ca decreased PR dissolution.

  13. 7 CFR 330.302 - Domestic movements of earth (including soil), stone, etc.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Domestic movements of earth (including soil), stone, etc. 330.302 Section 330.302 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE FEDERAL PLANT PEST REGULATIONS; GENERAL; PLANT PESTS; SOIL, STONE, AND QUARRY...

  14. Two Gonostomatid Ciliates from the Soil of Lombardia, Italy; including Note on the Soil Mapping Project.

    Science.gov (United States)

    Bharti, Daizy; Kumar, Santosh; La Terza, Antonietta

    2015-01-01

    Two gonostomatid ciliates, Gonostomum paronense n. sp. and G. strenuum, isolated from the soil sample of paddy field, Lombardia, Italy, were investigated using live observation and protargol impregnation. Gonostomum paronense n. sp. is mainly characterized by a tailed body, frontoventral cirri arranged in pairs, and presence of pretransverse and transverse cirri. Morphologically and morphometrically, the new species is similar to Gonostomum namibiense in having a tailed body and frontoventral cirral pairs; however, it differs mainly in the number of frontoventral cirral pairs (seven vs. three). Phylogenetic analyses based on the SSU rDNA sequences show that the new species is more closely related to G. namibiense than to G. strenuum, supporting the morphological classification based on the cirral pattern and the tailed body. However, due to the poor nodal support and absence of gene sequence of the type species Gonostomum, a more robust phylogeny of this group still remains unresolved. The biometric data of the Italian population of Gonostomum strenuum overlap with those from other known populations. Both species were collected from the industrial area of Parona, in the framework of the "Soil Mapping, Lombardia" project in which, for the first time in Italy, soil ciliates were used as bioindicators of soil quality. © 2015 The Author(s) Journal of Eukaryotic Microbiology © 2015 International Society of Protistologists.

  15. Soil Plant and plant mammal transfer factors

    NARCIS (Netherlands)

    de Nijs ACM; Vermeire TG

    1990-01-01

    In order to assess the lifetime hazard of ingestion exposure of man to new substances, the RIVM Assessment System for New Substances links environmental concentrations in water and soil to human exposure applying transfer factors. This report discusses indirect human exposure to new substances via

  16. Report on a workshop on the measurement of soils to plant transfer factors for radionuclides

    International Nuclear Information System (INIS)

    1982-01-01

    This report includes the proceedings of the workshop on soil-plant transfer factors of radionuclides. Part 1 deals with a general introduction of soil-plant transfer factors, recommendations for the determination of these transfer factors and computer listing of transfer factors specified according to nuclide; type of crop; type of soil; and type of experiment. The second part offers the 12 contributions presented, of which several are included in INIS separately. (G.J.P.)

  17. Seismic response of nuclear reactors in layered liquefiable soil deposits including nonlinear soil-structure interaction

    International Nuclear Information System (INIS)

    Zaman, M.; Mamoon, S.M.

    1989-01-01

    Analysis of seismic response of structures located at a site with potential for soil liquefaction has drawn attention of many researchers. The topic is particularly important in the design of critical facilities like nuclear reactors and defense installations. This paper presents the results of a study involving evaluation of coupled seismic response of structures (model nuclear reactors) and characteristics of soil liquefaction at a site. The analysis procedure employed is based on the nonlinear finite element (FE) technique and accounts for the interaction effects due to a neighboring structure. Emphasis is given to the following features: prediction of spatial and temporal variation of pore water pressure; identification of the on-set of liquefaction based on the effective stress approach, and tracing the propagation of the liquefied zones with time and resulting response of the structures

  18. Soil - plant experimental radionuclide transfer factors

    International Nuclear Information System (INIS)

    Dobrin, R.I.; Dulama, C.N.; Toma, Al.

    2006-01-01

    Some experimental research was performed in our institute to assess site specific soil-plant transfer factors. A full characterization of an experimental site was done both from pedo-chemical and radiological point of view. Afterwards, a certain number of culture plants were grown on this site and the evolution of their radionuclide burden was then recorded. Using some soil amendments one performed a parallel experiment and the radionuclide root uptake was evaluated and recorded. Hence, transfer parameters were calculated and some conclusions were drawn concerning the influence of site specific conditions on the root uptake of radionuclides. (authors)

  19. Risk Factors for Breast Cancer, Including Occupational Exposures

    Directory of Open Access Journals (Sweden)

    Elisabete Weiderpass

    2011-03-01

    Full Text Available The knowledge on the etiology of breast cancer has advanced substantially in recent years, and several etiological factors are now firmly established. However, very few new discoveries have been made in relation to occupational risk factors. The International Agency for Research on Cancer has evaluated over 900 different exposures or agents to-date to determine whether they are carcinogenic to humans. These evaluations are published as a series of Monographs (www.iarc.fr. For breast cancer the following substances have been classified as “carcinogenic to humans” (Group 1: alcoholic beverages, exposure to diethylstilbestrol, estrogen-progestogen contraceptives, estrogen-progestogen hormone replacement therapy and exposure to X-radiation and gamma-radiation (in special populations such as atomic bomb survivors, medical patients, and in-utero exposure. Ethylene oxide is also classified as a Group 1 carcinogen, although the evidence for carcinogenicity in epidemiologic studies, and specifically for the human breast, is limited. The classification “probably carcinogenic to humans” (Group 2A includes estrogen hormone replacement therapy, tobacco smoking, and shift work involving circadian disruption, including work as a flight attendant. If the association between shift work and breast cancer, the most common female cancer, is confirmed, shift work could become the leading cause of occupational cancer in women.

  20. Some factors including radiation affecting the productivity of proteinase enzymes by mucor lamprosporus

    International Nuclear Information System (INIS)

    El-Kabbany, H.M.I.

    1996-01-01

    In the present time, great attention has been focused on the production of milk clotting enzymes from microbial source for use as remain substitute due to the increasing demands on rennin for cheese making and the prohibition of the slaughter of small calves. The present investigation included the isolation and identification of remin-like enzyme fungal producers from different egyptian food and soil samples. Different factors including gamma radiation affecting the capability of selected isolate to produce the enzyme was also included. Special attention has also given to study the effect of different purification methods of the produced enzyme. The properties of the purified enzyme were also investigated

  1. Atmosphere-soil-vegetation model including CO2 exchange processes: SOLVEG2

    International Nuclear Information System (INIS)

    Nagai, Haruyasu

    2004-11-01

    A new atmosphere-soil-vegetation model named SOLVEG2 (SOLVEG version 2) was developed to study the heat, water, and CO 2 exchanges between the atmosphere and land-surface. The model consists of one-dimensional multilayer sub-models for the atmosphere, soil, and vegetation. It also includes sophisticated processes for solar and long-wave radiation transmission in vegetation canopy and CO 2 exchanges among the atmosphere, soil, and vegetation. Although the model usually simulates only vertical variation of variables in the surface-layer atmosphere, soil, and vegetation canopy by using meteorological data as top boundary conditions, it can be used by coupling with a three-dimensional atmosphere model. In this paper, details of SOLVEG2, which includes the function of coupling with atmosphere model MM5, are described. (author)

  2. Unsaturated Seepage Analysis of Cracked Soil including Development Process of Cracks

    Directory of Open Access Journals (Sweden)

    Ling Cao

    2016-01-01

    Full Text Available Cracks in soil provide preferential pathways for water flow and their morphological parameters significantly affect the hydraulic conductivity of the soil. To study the hydraulic properties of cracks, the dynamic development of cracks in the expansive soil during drying and wetting has been measured in the laboratory. The test results enable the development of the relationships between the cracks morphological parameters and the water content. In this study, the fractal model has been used to predict the soil-water characteristic curve (SWCC of the cracked soil, including the developmental process of the cracks. The cracked expansive soil has been considered as a crack-pore medium. A dual media flow model has been developed to simulate the seepage characteristics of the cracked expansive soil. The variations in pore water pressure at different part of the model are quite different due to the impact of the cracks. This study proves that seepage characteristics can be better predicted if the impact of cracks is taken into account.

  3. Earthquake analysis of structures including structure-soil interaction by a substructure method

    International Nuclear Information System (INIS)

    Chopra, A.K.; Guttierrez, J.A.

    1977-01-01

    A general substructure method for analysis of response of nuclear power plant structures to earthquake ground motion, including the effects of structure-soil interaction, is summarized. The method is applicable to complex structures idealized as finite element systems and the soil region treated as either a continuum, for example as a viscoelastic halfspace, or idealized as a finite element system. The halfspace idealization permits reliable analysis for sites where essentially similar soils extend to large depths and there is no rigid boundary such as soil-rock interface. For sites where layers of soft soil are underlain by rock at shallow depth, finite element idealization of the soil region is appropriate; in this case, the direct and substructure methods would lead to equivalent results but the latter provides the better alternative. Treating the free field motion directly as the earthquake input in the substructure method eliminates the deconvolution calculations and the related assumption -regarding type and direction of earthquake waves- required in the direct method. The substructure method is computationally efficient because the two substructures-the structure and the soil region- are analyzed separately; and, more important, it permits taking advantage of the important feature that response to earthquake ground motion is essentially contained in the lower few natural modes of vibration of the structure on fixed base. For sites where essentially similar soils extend to large depths and there is no obvious rigid boundary such as a soil-rock interface, numerical results for earthquake response of a nuclear reactor structure are presented to demonstrate that the commonly used finite element method may lead to unacceptable errors; but the substructure method leads to reliable results

  4. Indication of Importance of Including Soil Microbial Characteristics into Biotope Valuation Method.

    Czech Academy of Sciences Publication Activity Database

    Trögl, J.; Pavlorková, Jana; Packová, P.; Seják, J.; Kuráň, P.; Kuráň, J.; Popelka, J.; Pacina, J.

    2016-01-01

    Roč. 8, č. 3 (2016), č. článku 253. ISSN 2071-1050 Institutional support: RVO:67985858 Keywords : biotope assessment * biotope valuation method * soil microbial communities Subject RIV: DJ - Water Pollution ; Quality Impact factor: 1.789, year: 2016

  5. An approach to include soil carbon changes in life cycle assessments

    DEFF Research Database (Denmark)

    Petersen, Bjorn Molt; Knudsen, Marie Trydeman; Hermansen, John Erik

    2013-01-01

    to estimate carbon sequestration to be included in LCA is suggested and applied to two examples where the inclusion of carbon sequestration is especially relevant: 1) Bioenergy: removal of straw from a Danish soil for energy purposes and 2) Organic versus conventional farming: comparative study of soybean...... comparable to the IPCC 2006 tier I approach in a time perspective of 20 year, where after the suggested methodology showed a continued soil carbon change toward a new steady state. The suggested method estimated a carbon sequestration for the first example when storing straw in the soil instead of using...... it for bioenergy of 54, 97 and 213 kg C t(-1) straw C in a 200, 100 and 20 years perspective, respectively. For the conversion from conventional to organic soybean production, a difference of 32, 60 or 143 kg soil C ha(-1) yr(-1) in a 200,100 or 20 years perspective, respectively was found. The study indicated...

  6. Earthquake analysis of structures including structure-soil interaction by a substructure method

    International Nuclear Information System (INIS)

    Chopra, A.K.; Guttierrez, J.A.

    1977-01-01

    A general substructure method for analysis of response of nuclear power plant structures to earthquake ground motion, including the effects of structure-soil interaction, is summarized. The method is applicable to complex structures idealized as finite element systems and the soil region treated as either a continuum, for example as a viscoelastic halfspace, or idealized as a finite element system. The halfspace idealization permits reliable analysis for sites where essentially similar soils extend to large depths and there is no rigid boundary such as soil-rock interface. For sites where layers of soft soil are underlain by rock at shallow depth, finite element idealization of the soil region is appropriate; in this case, the direct and substructure methods would lead to equivalent results but the latter provides the better alternative. Treating the free field motion directly as the earthquake input in the substructure eliminates the deconvolution calculations and the related assumption-regarding type and direction of earthquake waves-required in the direct method. (Auth.)

  7. Differentiation of nitrous oxide emission factors for agricultural soils

    International Nuclear Information System (INIS)

    Lesschen, Jan Peter; Velthof, Gerard L.; Vries, Wim de; Kros, Johannes

    2011-01-01

    Nitrous oxide (N 2 O) direct soil emissions from agriculture are often estimated using the default IPCC emission factor (EF) of 1%. However, a large variation in EFs exists due to differences in environment, crops and management. We developed an approach to determine N 2 O EFs that depend on N-input sources and environmental factors. The starting point of the method was a monitoring study in which an EF of 1% was found. The conditions of this experiment were set as the reference from which the effects of 16 sources of N input, three soil types, two land-use types and annual precipitation on the N 2 O EF were estimated. The derived EF inference scheme performed on average better than the default IPCC EF. The use of differentiated EFs, including different regional conditions, allows accounting for the effects of more mitigation measures and offers European countries a possibility to use a Tier 2 approach. - Highlights: → We developed an N 2 O emission factor inference scheme for agricultural soils. → This scheme accounts for different N-input sources and environmental conditions. → The derived EF inference scheme performed better than the default IPCC EF. → The use of differentiated EFs allows for better accounting of mitigation measures. - Emission factors for nitrous oxide from agricultural soils are derived as a function of N-input sources and environmental conditions on the basis of empirical information.

  8. Model for prognostication of population irradiation dose at the soil way of long-living radionuclides including in food chains

    International Nuclear Information System (INIS)

    Prister, B.S.; Vinogradskaya, V.D.

    2009-01-01

    On the basis of modern pictures of cesium and strontium ion absorption mechanisms a soil taking complex was build the kinetic model of radionuclide migration from soil to plants. Model parameter association with the agricultural chemistry properties of soil, represented by complex estimation of soil properties S e f. The example of model application for prognostication of population internal irradiation dose due to consumption of milk at the soil way of long-living radionuclides including in food chains

  9. Study on Erosion Factors Affecting Kuroboku Soil Loss I. Water Permeability of Stratified Soil and Slope Gradient

    OpenAIRE

    田熊, 勝利; 猪迫, 耕二; 中原 恒,

    2005-01-01

    The authors examined the factors of bed soil affecting the loss of surface soil and the effects of these factors on the extent of the soil loss. They conducted a multivariate analysis using actual measurement value at a laboratory erosion experiment. They also conducted a simulation of erosion in soil loss using the bed soil factors. Soil loss quantity is dependent on the coefficient of permeability of bed soil; the steeper the latter is, the more the former increases. Lateral soil scattering...

  10. Impact of environmental factors and biological soil crust types on soil respiration in a desert ecosystem.

    Science.gov (United States)

    Feng, Wei; Zhang, Yuqing; Jia, Xin; Wu, Bin; Zha, Tianshan; Qin, Shugao; Wang, Ben; Shao, Chenxi; Liu, Jiabin; Fa, Keyu

    2014-01-01

    The responses of soil respiration to environmental conditions have been studied extensively in various ecosystems. However, little is known about the impacts of temperature and moisture on soils respiration under biological soil crusts. In this study, CO2 efflux from biologically-crusted soils was measured continuously with an automated chamber system in Ningxia, northwest China, from June to October 2012. The highest soil respiration was observed in lichen-crusted soil (0.93 ± 0.43 µmol m-2 s-1) and the lowest values in algae-crusted soil (0.73 ± 0.31 µmol m-2 s-1). Over the diurnal scale, soil respiration was highest in the morning whereas soil temperature was highest in the midday, which resulted in diurnal hysteresis between the two variables. In addition, the lag time between soil respiration and soil temperature was negatively correlated with the soil volumetric water content and was reduced as soil water content increased. Over the seasonal scale, daily mean nighttime soil respiration was positively correlated with soil temperature when moisture exceeded 0.075 and 0.085 m3 m-3 in lichen- and moss-crusted soil, respectively. However, moisture did not affect on soil respiration in algae-crusted soil during the study period. Daily mean nighttime soil respiration normalized by soil temperature increased with water content in lichen- and moss-crusted soil. Our results indicated that different types of biological soil crusts could affect response of soil respiration to environmental factors. There is a need to consider the spatial distribution of different types of biological soil crusts and their relative contributions to the total C budgets at the ecosystem or landscape level.

  11. Impact of Environmental Factors and Biological Soil Crust Types on Soil Respiration in a Desert Ecosystem

    Science.gov (United States)

    Feng, Wei; Zhang, Yuqing; Jia, Xin; Wu, Bin; Zha, Tianshan; Qin, Shugao; Wang, Ben; Shao, Chenxi; Liu, Jiabin; Fa, Keyu

    2014-01-01

    The responses of soil respiration to environmental conditions have been studied extensively in various ecosystems. However, little is known about the impacts of temperature and moisture on soils respiration under biological soil crusts. In this study, CO2 efflux from biologically-crusted soils was measured continuously with an automated chamber system in Ningxia, northwest China, from June to October 2012. The highest soil respiration was observed in lichen-crusted soil (0.93±0.43 µmol m−2 s−1) and the lowest values in algae-crusted soil (0.73±0.31 µmol m−2 s−1). Over the diurnal scale, soil respiration was highest in the morning whereas soil temperature was highest in the midday, which resulted in diurnal hysteresis between the two variables. In addition, the lag time between soil respiration and soil temperature was negatively correlated with the soil volumetric water content and was reduced as soil water content increased. Over the seasonal scale, daily mean nighttime soil respiration was positively correlated with soil temperature when moisture exceeded 0.075 and 0.085 m3 m−3 in lichen- and moss-crusted soil, respectively. However, moisture did not affect on soil respiration in algae-crusted soil during the study period. Daily mean nighttime soil respiration normalized by soil temperature increased with water content in lichen- and moss-crusted soil. Our results indicated that different types of biological soil crusts could affect response of soil respiration to environmental factors. There is a need to consider the spatial distribution of different types of biological soil crusts and their relative contributions to the total C budgets at the ecosystem or landscape level. PMID:25050837

  12. Spatial pattern of heavy metals accumulation risk in urban soils of Beijing and its influencing factors

    International Nuclear Information System (INIS)

    Liu, Rui; Wang, Meie; Chen, Weiping; Peng, Chi

    2016-01-01

    Accumulations of heavy metals in urban soils are highly spatial heterogeneity and affected by multiple factors including soil properties, land use and pattern, population and climatic conditions. We studied accumulation risks of Cd, Cu, Pb and Zn in unban soils of Beijing and their influencing based on the regression tree analysis and a GIS-based overlay model. Result shows that Zinc causes the most extensive soil pollution and Cu result in the most acute soil pollution. The soil's organic carbon content and CEC and population growth are the most significant factors affecting heavy metal accumulation. Other influence factors in land use pattern, urban landscape, and wind speed also contributed, but less pronounced. The soils in areas with higher degree of urbanization and surrounded by intense vehicular traffics have higher accumulation risk of Cd, Cu, Pb, and Zn. - Highlights: • Zn accumulations were the most extensive and Cu accumulations were the most acute. • Accumulations of Cd, Cu, Pb and Zn in urban soils were caused by different sets of influence factors. • Soil's organic carbon content and CEC and population growth were the most significant factors. • Accumulation risks were highly related with urbanization level and human activities. - A combined approach of employing geographical information systems and regression tree analyses identify the potential risks of accumulation Cd, Cu, Pb, and Zn in urban soils according to soil properties, urban land use patterns, urban landscape, demographics, and microclimatic conditions.

  13. Food Offer Inside Agroecosystem Soils as an Ecological Factor for Settling Microhabitats by Soil Saprophagous Mites

    Directory of Open Access Journals (Sweden)

    Jaroslav Smrž

    2015-01-01

    Full Text Available Mainly abiotic factors have been considered in examining soil fauna invasion or settlement. The role of soil animals communities was not considered. Our hypothesis, indeed, can be formulated: the structure and feeding habits of the soil animals community is not able to play some role in the soil rating. Localities, however, can be fragmented into microhabitats. We studied cultivated field and adjacent unploughed areas (so-called baulks, using the common Berlese–Tullgren apparatus for community structure studies followed by histological tests of food consumed by community members. We selected a group of oribatid mites, which are frequent and abundant. In the studied localities and their microhabitats, three groups of oribatid mites can be reported. First – ubiquitous species a second – migrants from the less-impacted to more-impacted microhabitats and third – specialists sensitive to severe environmental conditions in more-impacted microhabitat. They consequently live only in the less-severe, less-impacted unploughed soils and never migrate from these microhabitats. Their grazed and digested food is more diversified, and they included more feeding specialists.

  14. Dependence of soil-to-plant transfer factors of elements on their concentrations in soil

    International Nuclear Information System (INIS)

    Tsukada, Hirofumi; Watabe, Teruhisa.

    1996-01-01

    Transfer factors (TFs) of 31 stable elements from soil to plant were determined by neutron activation analysis. Soil and plant samples were collected from 112 farm fields in Aomori prefecture, Japan. The elements described are those that could be detected by this method, which include essential elements for plant growth and nonessential elements. Several of these elements were divided into two groups, each having different TF characteristics. In the first group of elements there was an inverse correlation between the TFs and the soil concentrations of the elements, especially for Cl, K and Ca. The concentrations of these elements in plants were independent of their soil concentrations. However, in the second group, especially Sc and Co, the TFs were independent of the soil concentrations of the elements. The fluctuation of TFs observed in this study was smaller than that previously reported. This may be attributed to the relatively narrow geographic area of the present study. In addition, the TFs for the stable elements in this study were generally one to three orders of magnitude lower than those compiled for radioactive isotopes in previous publications. (author)

  15. Seismic response and fragility evaluation for an Eastern US NPP including soil-structure interaction effects

    International Nuclear Information System (INIS)

    Ghiocel, Dan M.; Wilson, Paul R.; Thomas, Gary G.; Stevenson, John D.

    1998-01-01

    The paper discusses methodological aspects involved in a probabilistic seismic soil-structure interaction (SSI) analysis for a Seismic Probabilistic Risk Assessment (SPRA) review. An example of an Eastern US nuclear power plant (NPP) is presented. The approach presented herein follows the current practice of the Individual Plant Examination for External Events (IPEEE) program in the US. The NPP is founded on a relatively soft soil deposit, and thus the SSI effects on seismic responses are significant. Probabilistic models used for the idealization of the seismic excitation and the surrounding soil deposit are described. Using a lognormal format, computed random variability effects were combined with those proposed in the SPRA methodology guidelines. Probabilistic floor response spectra and structural fragilities for different NPP buildings were computed. Structural capacities were determined following the current practice which assumes independent median safety factors for strength and inelastic absorption. Limitations of the IPEEE practice for performing SPRA are discussed and alternate procedures, more rigorous and simple to implement, are suggested

  16. Finite element modeling of contaminant transport in soils including the effect of chemical reactions.

    Science.gov (United States)

    Javadi, A A; Al-Najjar, M M

    2007-05-17

    The movement of chemicals through soils to the groundwater is a major cause of degradation of water resources. In many cases, serious human and stock health implications are associated with this form of pollution. Recent studies have shown that the current models and methods are not able to adequately describe the leaching of nutrients through soils, often underestimating the risk of groundwater contamination by surface-applied chemicals, and overestimating the concentration of resident solutes. Furthermore, the effect of chemical reactions on the fate and transport of contaminants is not included in many of the existing numerical models for contaminant transport. In this paper a numerical model is presented for simulation of the flow of water and air and contaminant transport through unsaturated soils with the main focus being on the effects of chemical reactions. The governing equations of miscible contaminant transport including advection, dispersion-diffusion and adsorption effects together with the effect of chemical reactions are presented. The mathematical framework and the numerical implementation of the model are described in detail. The model is validated by application to a number of test cases from the literature and is then applied to the simulation of a physical model test involving transport of contaminants in a block of soil with particular reference to the effects of chemical reactions. Comparison of the results of the numerical model with the experimental results shows that the model is capable of predicting the effects of chemical reactions with very high accuracy. The importance of consideration of the effects of chemical reactions is highlighted.

  17. Spatial distribution of soil-transmitted helminths, including Strongyloides stercoralis, among children in Zanzibar

    Directory of Open Access Journals (Sweden)

    Stefanie Knopp

    2008-11-01

    Full Text Available A programme periodically distributing anthelminthic drugs to school-aged children for the control of soiltransmitted helminthiasis was launched in Zanzibar in the early 1990s. We investigated the spatial distribution of soiltransmitted helminth infections, including Strongyloides stercoralis, in 336 children from six districts in Unguja, Zanzibar, in 2007. One stool sample per child was examined with the Kato-Katz, Koga agar plate and Baermann methods. The point prevalence of the different helminth infections was compared to the geological characteristics of the study sites. The observed prevalences for Trichuris trichiura, Ascaris lumbricoides, hookworm and S. stercoralis were 35.5%, 12.2%, 11.9% and 2.2%, respectively, with considerable spatial heterogeneity. Whilst T. trichiura and hookworm infections were found in all six districts, no A. lumbricoides infections were recorded in the urban setting and only a low prevalence (2.2% was observed in the South district. S. stercoralis infections were found in four districts with the highest prevalence (4.0% in the West district. The prevalence of infection with any soil-transmitted helminth was highest in the North A district (69.6% and lowest in the urban setting (22.4%. A. lumbricoides, hookworm and, with the exception of the North B district, S. stercoralis infections were observed to be more prevalent in the settings north of Zanzibar Town, which are characterized by alluvial clayey soils, moist forest regions and a higher precipitation. After a decade of large-scale administration of anthelminthic drugs, the prevalence of soil-transmitted helminth infections across Unguja is still considerable. Hence, additional measures, such as improving access to adequate sanitation and clean water and continued health education, are warranted to successfully control soil-transmitted helminthiasis in Zanzibar.

  18. Modification of the USLE K factor for soil erodibility assessment on calcareous soils in Iran

    Science.gov (United States)

    Ostovari, Yaser; Ghorbani-Dashtaki, Shoja; Bahrami, Hossein-Ali; Naderi, Mehdi; Dematte, Jose Alexandre M.; Kerry, Ruth

    2016-11-01

    The measurement of soil erodibility (K) in the field is tedious, time-consuming and expensive; therefore, its prediction through pedotransfer functions (PTFs) could be far less costly and time-consuming. The aim of this study was to develop new PTFs to estimate the K factor using multiple linear regression, Mamdani fuzzy inference systems, and artificial neural networks. For this purpose, K was measured in 40 erosion plots with natural rainfall. Various soil properties including the soil particle size distribution, calcium carbonate equivalent, organic matter, permeability, and wet-aggregate stability were measured. The results showed that the mean measured K was 0.014 t h MJ- 1 mm- 1 and 2.08 times less than the estimated mean K (0.030 t h MJ- 1 mm- 1) using the USLE model. Permeability, wet-aggregate stability, very fine sand, and calcium carbonate were selected as independent variables by forward stepwise regression in order to assess the ability of multiple linear regression, Mamdani fuzzy inference systems and artificial neural networks to predict K. The calcium carbonate equivalent, which is not accounted for in the USLE model, had a significant impact on K in multiple linear regression due to its strong influence on the stability of aggregates and soil permeability. Statistical indices in validation and calibration datasets determined that the artificial neural networks method with the highest R2, lowest RMSE, and lowest ME was the best model for estimating the K factor. A strong correlation (R2 = 0.81, n = 40, p soils.

  19. Chemical factors of soil polution in Taganrog as population health risk factors

    Directory of Open Access Journals (Sweden)

    G.T. Aydinov

    2017-03-01

    Full Text Available Our research goal was to perform a hygienic assessment of soil pollution with chemicals on areas aimed for housing and recreation zones in Taganrog, Rostov region. Due to the fact that surface layer of city soils is an open dynamic system which is tightly connected to atmosphere and hydrosphere we treated pollutants content in soils as indicators of territory anthropogenic transformation and technogenic load on population. We used atomic-adsorption spectrophotometry to detect heavy metals and highly efficient liquid chromatography to detect 3,4-benzpyrene content. The results comprise 660 examined soil samples taken from 19 monitoring points; they were examined to detect 7 pollutants content (lead, zinc, copper, nickel, cadmium, chromium, and mercury over 2008–2015; 144 samples were examined to detect 3,4-benzpyrene content over 2013–2015. We determined that priority pollutants among detected metals were zinc and lead; their content in city soils amounted up to 5.91 and 1.95 maximum permissible concentration. Complex indicator of city soils contamination varied from 1.61 to 2.02, long-term average annual value being 1.83. 3,4-benzpyrene was confirmed to be a substantial risk factor for population health as its concentrations exceeded maximum allowable values in 65.28 % of examined soil samples at average and maximum concentrations (2.45 and 38.05 MPC correspondingly. We recommend to include this chemical into systematic environmental quality monitoring. We detected regional peculiarities of soil pollution with chemicals on city territories aimed for housing, territories of pre-school children facilities, and recreation zones.

  20. Variability of the soil-to-plant radiocaesium transfer factor for Japanese soils predicted with soil and plant properties.

    Science.gov (United States)

    Uematsu, Shinichiro; Vandenhove, Hildegarde; Sweeck, Lieve; Van Hees, May; Wannijn, Jean; Smolders, Erik

    2016-03-01

    Food chain contamination with radiocaesium (RCs) in the aftermath of the Fukushima accident calls for an analysis of the specific factors that control the RCs transfer. Here, soil-to-plant transfer factors (TF) of RCs for grass were predicted from the potassium concentration in soil solution (mK) and the Radiocaesium Interception Potential (RIP) of the soil using existing mechanistic models. The mK and RIP were (a) either measured for 37 topsoils collected from the Fukushima accident affected area or (b) predicted from the soil clay content and the soil exchangeable potassium content using the models that had been calibrated for European soils. An average ammonium concentration was used throughout in the prediction. The measured RIP ranged 14-fold and measured mK varied 37-fold among the soils. The measured RIP was lower than the RIP predicted from the soil clay content likely due to the lower content of weathered micas in the clay fraction of Japanese soils. Also the measured mK was lower than that predicted. As a result, the predicted TFs relying on the measured RIP and mK were, on average, about 22-fold larger than the TFs predicted using the European calibrated models. The geometric mean of the measured TFs for grass in the affected area (N = 82) was in the middle of both. The TFs were poorly related to soil classification classes, likely because soil fertility (mK) was obscuring the effects of the soil classification related to the soil mineralogy (RIP). This study suggests that, on average, Japanese soils are more vulnerable than European soils at equal soil clay and exchangeable K content. The affected regions will be targeted for refined model validation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Composting of soils/sediments and sludges containing toxic organics including high energy explosives. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, R.C.; Kitchens, J.F.

    1993-07-01

    Laboratory and pilot-scale experimentation were conducted to evaluate composting as an on-site treatment technology to remediate soils contaminated with hazardous waste at DOE`s PANTEX Plant. Suspected contaminated sites within the PANTEX Plant were sampled and analyzed for explosives, other organics, and inorganic wastes. Soils in drainage ditches and playas at PANTEX Plant were found to be contaminated with low levels of explosives (including RDX, HMX, PETN and TATB). Additional sites previously used for solvent disposal were heavily contaminated with solvents and transformation products of the solvent, as well as explosives and by-products of explosives. Laboratory studies were conducted using {sup 14}C-labeled explosives and {sup 14}C-labeled diacetone alcohol contaminated soil loaded into horse manure/hay composts at three rates: 20, 30, and 40%(W/W). The composts were incubated for six weeks at approximately 60{degree}C with continuous aeration. All explosives degraded rapidly and were reduced to below detection limits within 3 weeks in the laboratory studies. {sup 14}C-degradates from {sup 14}C-RDX, {sup 14}C-HMX and {sup 14}C-TATB were largely limited to {sup 14}CO{sub 2} and unextracted residue in the compost. Volatile and non-volatile {sup 14}C-degradates were found to result from {sup 14}C-PETN breakdown, but these compounds were not identified. {sup 14}C-diacetone alcohol concentrations were significantly reduced during composting. However, most of the radioactivity was volatilized from the compost as non-{sup 14}CO{sub 2} degradates or as {sup 14}C-diacetone alcohol. Pilot scale composts loaded with explosives contaminated soil at 30% (W/W) with intermittent aeration were monitored over six weeks. Data from the pilot-scale study generally was in agreement with the laboratory studies. However, the {sup 14}C-labeled TATB degraded much faster than the unlabeled TATB. Some formulations of TATB may be more resistant to composting activity than others.

  2. Physical and chemical factors influencing radionuclide behaviour in arable soils

    International Nuclear Information System (INIS)

    Rauret, G.; Vidal, M.; Alexakhin, R.M.; Kruglov, S.V.; Cremers, A.; Wauters, J.; Valcke, E.; Ivanov, Y.

    1996-01-01

    Soil-to-plant transfer of radionuclides integrates plant physiological and soil chemical aspects. Therefore, it is necessary to study the factors affecting the equilibrium of the radionuclides between solid and soil solution phases. Desorption and adsorption studies were applied to the podsolic and peat soils considered in the ECP-2 project. In the desorption approach, both sequential extraction and 'infinite bath' techniques were used. In the adsorption approach, efforts were directed at predicting Cs and Sr-K D on the basis of soil properties and soil solution composition. Desorption approach predicts time-dynamics of transfer with time but it is un sufficient for comparatively predicting transfer. Adsorption studies informs about which are the key factors affecting radionuclide transfer. For Sr, availability depends on the CEC and on the concentration of the Ca + Mg in the soil solution. For Cs, availability is mainly dependent on the partitioning between FES -frayed edge sites-, which are highly specific and REC -regular exchange complex-, with low selectivity for Cs. Moreover, availability depends on the K and NH 4 , levels in the soil solution and fixation properties of the soil. Considering these factors, the calculation of the in situ K D values helps to predict the relative transfer of radionuclides. The calculation of the K D of the materials that could be used as countermeasures could permit the prediction of its suitability to decrease transfer and therefore to help in producing cleaner agricultural products

  3. Chapter 7. Assessing soil factors in wildland improvement programs

    Science.gov (United States)

    Arthur R. Tiedemann; Carlos F. Lopez

    2004-01-01

    Soil factors are an important consideration for successful wildland range development or improvement programs. Even though many soil improvement and amelioration practices are not realistic for wildlands, their evaluation is an important step in selection of adapted plant materials for revegetation. This chapter presents information for wildland managers on: the...

  4. What are the most crucial soil factors for predicting the distribution of alpine plant species?

    Science.gov (United States)

    Buri, A.; Pinto-Figueroa, E.; Yashiro, E.; Guisan, A.

    2017-12-01

    Nowadays the use of species distribution models (SDM) is common to predict in space and time the distribution of organisms living in the critical zone. The realized environmental niche concept behind the development of SDM imply that many environmental factors must be accounted for simultaneously to predict species distributions. Climatic and topographic factors are often primary included, whereas soil factors are frequently neglected, mainly due to the paucity of soil information available spatially and temporally. Furthermore, among existing studies, most included soil pH only, or few other soil parameters. In this study we aimed at identifying what are the most crucial soil factors for explaining alpine plant distributions and, among those identified, which ones further improve the predictive power of plant SDMs. To test the relative importance of the soil factors, we performed plant SDMs using as predictors 52 measured soil properties of various types such as organic/inorganic compounds, chemical/physical properties, water related variables, mineral composition or grain size distribution. We added them separately to a standard set of topo-climatic predictors (temperature, slope, solar radiation and topographic position). We used ensemble forecasting techniques combining together several predictive algorithms to model the distribution of 116 plant species over 250 sites in the Swiss Alps. We recorded the variable importance for each model and compared the quality of the models including different soil proprieties (one at a time) as predictors to models having only topo-climatic variables as predictors. Results show that 46% of the soil proprieties tested become the second most important variable, after air temperature, to explain spatial distribution of alpine plants species. Moreover, we also assessed that addition of certain soil factors, such as bulk soil water density, could improve over 80% the quality of some plant species models. We confirm that soil p

  5. Deriving site-specific soil clean-up values for metals and metalloids: rationale for including protection of soil microbial processes.

    Science.gov (United States)

    Kuperman, Roman G; Siciliano, Steven D; Römbke, Jörg; Oorts, Koen

    2014-07-01

    Although it is widely recognized that microorganisms are essential for sustaining soil fertility, structure, nutrient cycling, groundwater purification, and other soil functions, soil microbial toxicity data were excluded from the derivation of Ecological Soil Screening Levels (Eco-SSL) in the United States. Among the reasons for such exclusion were claims that microbial toxicity tests were too difficult to interpret because of the high variability of microbial responses, uncertainty regarding the relevance of the various endpoints, and functional redundancy. Since the release of the first draft of the Eco-SSL Guidance document by the US Environmental Protection Agency in 2003, soil microbial toxicity testing and its use in ecological risk assessments have substantially improved. A wide range of standardized and nonstandardized methods became available for testing chemical toxicity to microbial functions in soil. Regulatory frameworks in the European Union and Australia have successfully incorporated microbial toxicity data into the derivation of soil threshold concentrations for ecological risk assessments. This article provides the 3-part rationale for including soil microbial processes in the development of soil clean-up values (SCVs): 1) presenting a brief overview of relevant test methods for assessing microbial functions in soil, 2) examining data sets for Cu, Ni, Zn, and Mo that incorporated soil microbial toxicity data into regulatory frameworks, and 3) offering recommendations on how to integrate the best available science into the method development for deriving site-specific SCVs that account for bioavailability of metals and metalloids in soil. Although the primary focus of this article is on the development of the approach for deriving SCVs for metals and metalloids in the United States, the recommendations provided in this article may also be applicable in other jurisdictions that aim at developing ecological soil threshold values for protection of

  6. Study on the influence factors about the soil radon measurement

    International Nuclear Information System (INIS)

    Wu Zixiang; Liu Yanbin; Jia Yuxin; Mai Weiji; Liu Xiaolian; Yang Yuhua

    2006-01-01

    Objective: To explore relevant factors about the soil radon measurement and provide gist of formulating correct measure method by studying the way of the soil radon measurement. Methods: Deflation-ionization room standard is adopted. Results: The concentration of soil radon becomes higher with the sample's volume added, it also augmented with the measure depth increased in certain degree; The concentration of soil radon changes little when sample's depth is above 60 cm; The time of deflation has no obvious influence on the concentration of soil radon, but microwave show serious effect on it; The results will be lowered when the desiccant is humidified, raining has the same affection on it; Plant has some impact on it. Conclusion: The measured results will be affected by microwave, oscillate and plant. Sample's volume and depth, soil's humidity can influence it too. The result's veracity can be guaranteed by choosing appropriate sample and measure condition. (authors)

  7. Potential factors affecting accumulation of unsupported 210Pb in soil

    International Nuclear Information System (INIS)

    Mihailović, Aleksandra; Vučinić Vasić, Milica; Todorović, Nataša; Hansman, Jan; Vasin, Jovica; Krmar, Miodrag

    2014-01-01

    Airborne 210 Pb, daughter of 222 Rn, is frequently used as a tracer in different studies concerning atmospheric transport, sedimentation, soil erosion, dating, etc. Concentration of 210 Pb was measured in 40 soil samples collected in urban and industrial areas in order to get evidence of possible influence of some factors on accumulation of airborne 210 Pb in soil. Different soil properties such as the content of organic matter, free CaCO 3 , and available phosphorus (P 2 O 5 ) were measured to explore their possible correlation with the amount of 210 Pb. Special attention was given to the correlation between 210 Pb and stable lead accumulated in the soil. Several samples were taken near a battery manufacturer to check if extremely high concentrations of lead can affect the uptake of the airborne 210 Pb in soil. Soil samples were also taken at different depths to investigate the penetration of lead through the soil. - Highlights: • 210 Pb and 137 Cs were measured in samples of urban soil. • Organic matter, free CaCO 3 content, available phosphorus, and lead were measured in soil samples. • There is no statistically significant correlation between 210 Pb and lead, CaCO 3 and phosphorus. • A strong positive correlation between 210 Pb and organic matter was observed

  8. Elucidating key factors affecting radionuclide aging in soils

    Energy Technology Data Exchange (ETDEWEB)

    Roig, M. [Universitat Politecnica Catalunya, Institut de Tecniques Energetiques, Barcelona (Spain); Rigola, A.; Vidal, M.; Rauret, G. [Barcelona Univ., Dept. de Quimica Analitica (Spain)

    2004-07-01

    Mechanistic studies allow at present to describe the processes governing the short-term interaction of radiostrontium and radiocaesium in soils. The initial sorption step can be described through the estimation of the soil-soil solution distribution coefficient from soil parameters, as cationic exchange capacity, radiocaesium interception potential and concentration of competing ions in the soil solution. After the initial soil-radionuclide interaction, a fraction of radionuclide is no longer available for exchange with the solution, and it remains fixed in the solid fraction. At present, the initial fixed fraction of a radionuclide in a given soil cannot be predicted from soil properties. Besides, little is known about soil and environmental factors (e.g., temperature; hydric regime) provoking the increase in the fixed fraction with time, the so-called aging process. This process is considered to control the reduction of food contamination with time at contaminated scenarios. Therefore, it is crucial to be able to predict the radionuclide aging in the medium and long term for a better risk assessment, especially when a decision has to be made between relying on natural attenuation versus implementing intervention actions. Here we study radiostrontium and radiocaesium aging in a set of soils, covering a wide range of soil types of contrasting properties (e.g., loamy calcareous; podzol; chernozem, organic). Three factors are separately and simultaneously tested: time elapsed since contamination, temperature and hydric regime. Changes in the radionuclide fixed fraction are estimated with a leaching test based on the use of a mild extractant solution. In addition to this, secondary effects on the radiocaesium interception potential in various soils are also considered. (author)

  9. Soil-plant transfer factors in forest ecosystems

    International Nuclear Information System (INIS)

    Strebl, F.; Gerzabek, M.H.

    1995-04-01

    Within scope of an extended study about 137 Cs behaviour in forest ecosystems several parameters were found to influence soil-plant transfer factors. TF-values of different plant species cover a range of two magnitudes. This is partly due to variations in rooting depth of plants and specific physiological adaptations of nutrient supply. Perrenial plants like trees (Picea abies) and dwarf shrubs (Vaccinium myrtillus) showed a distinct age - dependency of 137 Cs - transfer factors. In young plant parts caesium concentration is higher than in old, more signified twigs. A correlation analysis of physico-chemical soil parameters and TF-values to forest vegetation showed, that soil organic matter, especially the degree of humification and the ratio between extractable fulvic to humic acids are important influencing factors of 137 Cs transfer from forest soils to plants. (author)

  10. Ecological factors governing the distribution of soil microfungi in some forest soils of Pachmarhi Hills, India

    Directory of Open Access Journals (Sweden)

    Shashi Chauhan

    2014-01-01

    Full Text Available An ecological study of the microfungi occurring in the various forest soils of Pachmarhi Hills, India has been carried-out by the soil plate technique. Soil samples from 5 different forest communities viz., moist deciduous forest dominated by tree ferns, Diospyros forest, Terminalia forest, Shorea forest and scrub forest dominated by Acacia and Dalbergia sp. were collected during October, 1983. Some physico-chemical characteristics of the soil were analysed and their role in distribution of fungi in 5 soil types was studied and discussed. 43 fungal species were isolated, of which Asperigillus niger I and Penicillium janthinellum occurred in all the 5 soil types. Statistically, none of the edaphic factors showed positive significant correlation with the number of fungi.

  11. Factors affecting soil erosion in Beijing mountain forestlands | Zhang ...

    African Journals Online (AJOL)

    The role of regions, vegetation types and forest stand density in controlling soil erosion were investigated in Beijing mountain forest, China. The main objective was to develop some models to estimate soil erosion under different forest conditions including regions, vegetation type, and stand density as influenced by artificial ...

  12. Using DTPA-extractable soil fraction to assess the bioconcentration factor of plants in phytoremediation of urban soils

    Science.gov (United States)

    Rodríguez-Bocanegra, Javier; Roca, Núria; Tume, Pedro; Bech, Jaume

    2017-04-01

    Urban soils may be highly contaminated with potentially toxic metals, as a result of intensive anthropogenic activities. Developing cities are increasing the number of lands where is practiced the urban agriculture. In this way, it is necessary to assess the part of heavy metals that is transferred to plants in order to a) know the potential health risk that represent soils and b) know the relation soil-plant to assess the ability of these plants to remove heavy metals from soil. Nowadays, to assess the bioconcentration factor (BF) of plants in phytoremediation, the pseudototal o total concentration has been used by many authors. Two different urban soils with similar pH and carbonates content but with different pollution degree were phytoremediated with different plant species. Urban soil from one Barcelona district (Spain), the most contaminated soil, showed an extractability of Cu, Pb and Zn of 9.6, 6.7 and 5.8% of the total fraction respectively. The soil from Talcahuano city (Chile), with contents of heavy metals slightly above the background upper limit, present values of 15.5, 13.5 and 12% of the total fraction of studied heavy metals. Furthermore, a peri-urban analysed soil from Azul (Argentina) also showed an elevated extractability with values of 24, 13.5 and 14% of the Cu, Pb and Zn contents respectively. These soils presented more extractability than other disturbed soils, like for example, soils from mine areas. The urban soils present more developed soil with an interaction between solution and solid phase in polluted systems. The most important soil surface functional groups include the basal plane of phyllosilicates and metal hydroxyls at edge sites of clay minerals, iron oxyhydroxides, manganese oxyhydroxides and organic matter. The interaction between solution and solid phase in polluted urban systems tends to form labile associations and pollutants are more readily mobilized because their bonds with soil particles are weaker. Clay and organic

  13. Dissipation of sulfamethoxazole in pasture soils as affected by soil and environmental factors.

    Science.gov (United States)

    Srinivasan, Prakash; Sarmah, Ajit K

    2014-05-01

    The dissipation of sulfamethoxazole (SMO) antibiotic in three different soils was investigated through laboratory incubation studies. The experiments were conducted under different incubation conditions such as initial chemical concentration, soil depth, temperature, and with sterilisation. The results indicate that SMO dissipated rapidly in New Zealand pasture soils, and the 50% dissipation times (DT50) in Hamilton, Te Kowhai and Horotiu soils under non-sterile conditions were 9.24, 4.3 and 13.33 days respectively. During the incubation period for each sampling event the soil dehydrogenase activity (DHA) and the variation in microbial community were monitored thorough phospholipid fatty acid extraction analysis (PLFA). The DHA data correlated well with the dissipation rate constants of SMO antibiotic, an increase in the DHA activity resulted in faster antibiotic dissipation. The PLFA analysis was indicative of higher bacterial presence as compared to fungal community, highlighting the type of microbial community responsible for dissipation. The results indicate that with increasing soil depth, SMO dissipation in soil was slower (except for Horotiu) while with increase in temperature the antibiotic loss was faster, and was noticeable in all the soils. Both the degree of biological activity and the temperature of the soil influenced overall SMO dissipation. SMO is not likely to persist more than 5-6 months in all three soils suggesting that natural biodegradation may be sufficient for the removal of these contaminants from the soil. Its dissipation in sterile soils indicated abiotic factors such as strong sorption onto soil components to play a role in the dissipation of SMO. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. A statistical approach to estimating soil-to-plant transfer factor of strontium in agricultural fields

    International Nuclear Information System (INIS)

    Ishikawa, Nao; Tagami, Keiko; Uchida, Shigeo

    2009-01-01

    Soil-to-plant transfer factor (TF) is one of the important parameters in radiation dose assessment models for the environmental transfer of radionuclides. Since TFs are affected by several factors, including radionuclides, plant species and soil properties, development of a method for estimation of TF using some soil and plant properties would be useful. In this study, we took a statistical approach to estimating the TF of stable strontium (TF Sr ) from selected soil properties and element concentrations in plants, which was used as an analogue of 90 Sr. We collected the plant and soil samples used for the study from 142 agricultural fields throughout Japan. We applied a multiple linear regression analysis in order to get an empirical equation to estimate TF Sr . TF Sr could be estimated from the Sr concentration in soil (C Sr soil ) and Ca concentration in crop (C Ca crop ) using the following equation: log TF Sr =-0.88·log C Sr soil +0.93·log C Ca crop -2.53. Then, we replaced our data with Ca concentrations in crops from a food composition database compiled by the Japanese government. Finally, we predicted TF Sr using Sr concentration in soil from our data and Ca concentration in crops from the database of food composition. (author)

  15. Influences Factors of the Cadmium Removal by Magnetic Solid Chelator Powder(MSC in Soil

    Directory of Open Access Journals (Sweden)

    LIU Jun-long

    2017-12-01

    Full Text Available Pot experiments were conducted for the purpose of analyzing the influencing effects for the magnetic solid chelator powder(MSC, magnetic solid chelator powder on removal of cadmium pollution in the soil. The influencing factors included straws,air drying,activation structural material, stirring time and repetition times, etc. The results showed that the straw addition in the soil decreased the removal efficiency of Cd. The different air drying degree in the soil also had the effect of MSC. The air drying in the soil affected the results more by comparison with the straws. When stirring time was 40 min, the removal rate of Cd was 22.67% and achieved the best removal efficiency. With the increasing of stirring time, the effect of MSC on Cd removal increased first, then decreased. Drying MSC material lost the effect of Cd removal in the soil. After activation(soaking in water for 12 h, MSC material could remov Cd in the soil once again. MSC material had removal and remediation effects on soil Cd, the removal effects depended on soil properties, material properties and operation process and other factors. The research of MSC materials in soil remediation had important practical significance.

  16. Transfer factors of Polonium from soil to parsley and mint

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Al-Hamwi, A.; Eadan, Z.; Amin, Y.

    2010-01-01

    Transfer factors of 210 Po from soil to parsley and mint have been determined. Artificial polonium isotope ( 208 Po) was used as a tracer to determine transfer factor of Po from soil to plant in pot experiments. Two plant growing systems were used for this study namely, an outdoor system and a sheltered system by a polyethylene tent. 208 Po and 210 Po were determined in soil and different parts of the studied plants (stem and leaf), using alpha spectroscopy. The results have shown that there was a clear uptake of 208 Po by roots to leaves and stems of both plants. Higher values of transfer factors using the 210 Po activity concentrations than the 208 Po activity concentration were observed. Transfer factors of 210 Po from soil to parsley varied between 20 x 10 -2 and 50 x 10 -2 and 22 x 10 -3 and 67 x 10 -3 in mint, while 208 Po transfer factors varied between 4 x 10 -2 and 12 x 10 -2 for parsley and 10 x 10 -2 and 22 x 10 -2 in mint. Transfer factors of Po were higher in those plants grown in the sheltered system than in the open system; about 75% of Po was transferred from atmosphere to parsley parts using the two systems. Ratios of transferred Po from soil to mint stem and leaf in the sheltered system were higher by 2 times from those in the open system.

  17. Including Below Detection Limit Samples in Post Decommissioning Soil Sample Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hwan; Yim, Man Sung [KAIST, Daejeon (Korea, Republic of)

    2016-05-15

    To meet the required standards the site owner has to show that the soil at the facility has been sufficiently cleaned up. To do this one must know the contamination of the soil at the site prior to clean up. This involves sampling that soil to identify the degree of contamination. However there is a technical difficulty in determining how much decontamination should be done. The problem arises when measured samples are below the detection limit. Regulatory guidelines for site reuse after decommissioning are commonly challenged because the majority of the activity in the soil at or below the limit of detection. Using additional statistical analyses of contaminated soil after decommissioning is expected to have the following advantages: a better and more reliable probabilistic exposure assessment, better economics (lower project costs) and improved communication with the public. This research will develop an approach that defines an acceptable method for demonstrating compliance of decommissioned NPP sites and validates that compliance. Soil samples from NPP often contain censored data. Conventional methods for dealing with censored data sets are statistically biased and limited in their usefulness.

  18. The Impact of Including Below Detection Limit Samples in Post Decommissioning Soil Sample Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Hwan; Yim, Man-Sung [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    To meet the required standards the site owner has to show that the soil at the facility has been sufficiently cleaned up. To do this one must know the contamination of the soil at the site prior to clean up. This involves sampling that soil to identify the degree of contamination. However there is a technical difficulty in determining how much decontamination should be done. The problem arises when measured samples are below the detection limit. Regulatory guidelines for site reuse after decommissioning are commonly challenged because the majority of the activity in the soil at or below the limit of detection. Using additional statistical analyses of contaminated soil after decommissioning is expected to have the following advantages: a better and more reliable probabilistic exposure assessment, better economics (lower project costs) and improved communication with the public. This research will develop an approach that defines an acceptable method for demonstrating compliance of decommissioned NPP sites and validates that compliance. Soil samples from NPP often contain censored data. Conventional methods for dealing with censored data sets are statistically biased and limited in their usefulness. In this research, additional methods are performed using real data from a monazite manufacturing factory.

  19. Toxicity of pesticides associated with potato production, including soil fumigants, to snapping turtle eggs (Chelydra serpentina).

    Science.gov (United States)

    de Solla, Shane Raymond; Palonen, Kimberley Elizabeth; Martin, Pamela Anne

    2014-01-01

    Turtles frequently oviposit in soils associated with agriculture and, thus, may be exposed to pesticides or fertilizers. The toxicity of a pesticide regime that is used for potato production in Ontario on the survivorship of snapping turtle (Chelydra serpentina) eggs was evaluated. The following treatments were applied to clean soil: 1) a mixture of the pesticides chlorothalonil, S-metolachlor, metribuzin, and chlorpyrifos, and 2) the soil fumigant metam sodium. Turtle eggs were incubated in soil in outdoor plots in which these mixtures were applied at typical and higher field application rates, where the eggs were subject to ambient temperature and weather conditions. The pesticide mixture consisting of chlorothalonil, S-metolachlor, metribuzin, and chlorpyrifos did not affect survivorship, deformities, or body size at applications up to 10 times the typical field application rates. Hatching success ranged between 87% and 100% for these treatments. Metam sodium was applied at 0.1¯ times, 0.3¯ times, 1 times, and 3 times field application rates. Eggs exposed to any application of metam sodium had 100% mortality. At typical field application rates, the chemical regime associated with potato production does not appear to have any detrimental impacts on turtle egg development, except for the use of the soil fumigant metam sodium, which is highly toxic to turtle eggs at the lowest recommended application rate. © 2013 SETAC.

  20. Nonlinear dynamic analysis of framed structures including soil-structure interaction effects

    International Nuclear Information System (INIS)

    Mahmood, M.N.; Ahmed, S.Y.

    2008-01-01

    The role of oil-structure interaction on seismic behavior of reinforced concrete structures is investigated in this paper. A finite element approach has been adopted to model the interaction system that consists of the reinforced concrete plane frame, soil deposit and interface which represents the frictional between foundation of the structure and subsoil. The analysis is based on the elasto-plastic behavior of the frame members (beams and columns) that is defined by the ultimate axial force-bending moment interaction curve, while the cap model is adopted to govern the elasto-plastic behavior of the soil material. Mohr-Coulomb failure law is used to determine the initiation of slippage at the interface, while the separation is assumed to determine the initiation of slippage at the interface, while the separation is assumed to occur when the stresses at the interface becomes tension stresses. New-Mark's Predictor-Corrector algorithm is adopted for nonlinear dynamic analysis. The main aim of present work is to evaluate the sensitivity of structures to different behavior of the soil and interface layer when subjected to an earthquake excitation. Predicted results of the dynamic analysis of the interaction system indicate that the soil-structure interaction problem can have beneficial effects on the structural behavior when different soil models (elastic and elasto-plastic) and interface conditions (perfect bond and permitted slip)are considered. (author)

  1. Probabilistic and deterministic soil structure interaction analysis including ground motion incoherency effects

    International Nuclear Information System (INIS)

    Elkhoraibi, T.; Hashemi, A.; Ostadan, F.

    2014-01-01

    Soil-structure interaction (SSI) is a major step for seismic design of massive and stiff structures typical of the nuclear facilities and civil infrastructures such as tunnels, underground stations, dams and lock head structures. Currently most SSI analyses are performed deterministically, incorporating limited range of variation in soil and structural properties and without consideration of the ground motion incoherency effects. This often leads to overestimation of the seismic response particularly the In-Structure-Response Spectra (ISRS) with significant impositions of design and equipment qualification costs, especially in the case of high-frequency sensitive equipment at stiff soil or rock sites. The reluctance to incorporate a more comprehensive probabilistic approach is mainly due to the fact that the computational cost of performing probabilistic SSI analysis even without incoherency function considerations has been prohibitive. As such, bounding deterministic approaches have been preferred by the industry and accepted by the regulatory agencies. However, given the recently available and growing computing capabilities, the need for a probabilistic-based approach to the SSI analysis is becoming clear with the advances in performance-based engineering and the utilization of fragility analysis in the decision making process whether by the owners or the regulatory agencies. This paper demonstrates the use of both probabilistic and deterministic SSI analysis techniques to identify important engineering demand parameters in the structure. A typical nuclear industry structure is used as an example for this study. The system is analyzed for two different site conditions: rock and deep soil. Both deterministic and probabilistic SSI analysis approaches are performed, using the program SASSI, with and without ground motion incoherency considerations. In both approaches, the analysis begins at the hard rock level using the low frequency and high frequency hard rock

  2. Probabilistic and deterministic soil structure interaction analysis including ground motion incoherency effects

    Energy Technology Data Exchange (ETDEWEB)

    Elkhoraibi, T., E-mail: telkhora@bechtel.com; Hashemi, A.; Ostadan, F.

    2014-04-01

    Soil-structure interaction (SSI) is a major step for seismic design of massive and stiff structures typical of the nuclear facilities and civil infrastructures such as tunnels, underground stations, dams and lock head structures. Currently most SSI analyses are performed deterministically, incorporating limited range of variation in soil and structural properties and without consideration of the ground motion incoherency effects. This often leads to overestimation of the seismic response particularly the In-Structure-Response Spectra (ISRS) with significant impositions of design and equipment qualification costs, especially in the case of high-frequency sensitive equipment at stiff soil or rock sites. The reluctance to incorporate a more comprehensive probabilistic approach is mainly due to the fact that the computational cost of performing probabilistic SSI analysis even without incoherency function considerations has been prohibitive. As such, bounding deterministic approaches have been preferred by the industry and accepted by the regulatory agencies. However, given the recently available and growing computing capabilities, the need for a probabilistic-based approach to the SSI analysis is becoming clear with the advances in performance-based engineering and the utilization of fragility analysis in the decision making process whether by the owners or the regulatory agencies. This paper demonstrates the use of both probabilistic and deterministic SSI analysis techniques to identify important engineering demand parameters in the structure. A typical nuclear industry structure is used as an example for this study. The system is analyzed for two different site conditions: rock and deep soil. Both deterministic and probabilistic SSI analysis approaches are performed, using the program SASSI, with and without ground motion incoherency considerations. In both approaches, the analysis begins at the hard rock level using the low frequency and high frequency hard rock

  3. Soil-to-plant concentration factors for radiological assessments

    International Nuclear Information System (INIS)

    Ng, Y.C.; Thompson, S.E.; Colsher, C.S.

    1982-09-01

    This report presents the results of a literature review to derive soil-to-plant concentration factors to predict the concentration of a radionuclide in plants from that in soil. The concentration factor, B/sub v/ is defined as the ratio of the concentration of a nuclide in the edible plant part to that in dry soil. CR (the concentration ratio) is similarly defined to denote the concentration factor for dry feed consumed by livestock. B/sub v/ and CR values are used to assess the dose from radionuclides deposited onto soil and transferred into crop plants via roots. Approaches for deriving B/sub v/ and CR values are described, and values for food and feed are tabulated for individual elements. The sources of uncertainty are described, and the factors that contribute to the inherent variability of the B/sub v/ and CR values are discussed. Summary tables of elemental B/sub v/ and CR values and statistical parameters that characterize their distributions provide a basis for a systematic updating of many of the B/sub v/ values in Regulatory Guide 1.109. They also provide a basis for selecting B/sub v/ and CR values for other applications that involve the use of equilibrium models to predict the concentration of radionuclides in plants from that in soil

  4. The Influence of Soil Chemical Factors on In Situ Bioremediation of Soil Contamination

    Energy Technology Data Exchange (ETDEWEB)

    Breedveld, Gijs D.

    1997-12-31

    Mineral oil is the major energy source in Western society. Production, transport and distribution of oil and oil products cause serious contamination problems of water, air and soil. The present thesis studies the natural biodegradation processes in the soil environment which can remove contamination by oil products and creosote. The main physical/chemical processes determining the distribution of organic contaminants between the soil solid, aqueous and vapour phase are discussed. Then a short introduction to soil microbiology and environmental factors important for biodegradation is given. There is a discussion of engineered and natural bioremediation methods and the problems related to scaling up laboratory experiments to field scale remediation. Bioremediation will seldom remove the contaminants completely; a residue remains. Factors affecting the level of residual contamination and the consequences for contaminant availability are discussed. Finally, the main findings of the work are summarized and recommendations for further research are given. 111 refs., 41 figs., 19 tabs.

  5. Seismic evaluation of a cooling water reservoir facility including fluid-structure and soil-structure interaction effects

    International Nuclear Information System (INIS)

    Kabir, A.F.; Maryak, M.E.

    1991-01-01

    Seismic analyses and structural evaluations were performed for a cooling water reservoir of a nuclear reactor facility. The horizontal input seismic motion was the NRC Reg. guide 1.60 spectrum shape anchored at 0.20g zero period acceleration. Vertical input was taken as two-thirds of the horizontal input. Soil structure interaction and hydrodynamic effects were addressed in the seismic analyses. Uncertainties in the soil properties were accounted for by considering three soil profiles. Two 2-dimensional SSI models and a 3-dimensional static model. Representing different areas of the reservoir structures were developed and analyzed to obtain seismic forces and moments, and accelerations at various locations. The results included in this paper indicated that both hydrodynamic and soil-structure interaction effects are significant contributors to the seismic responses of the water-retaining walls of the reservoir

  6. 3rd Report of the workgroup on soil-to-plant transfer factors

    International Nuclear Information System (INIS)

    1984-01-01

    This report presents about 2000 soil-to-plant transfer factors obtained in different countries. They are included in a data bank compiled by the different IUR working groups. Some remarks on organisation and present status of the data bank, are followed up with 11 contributions presented at the conference, of which 5 are included in Atomindex separately. (Auth.)

  7. Spatial Data Mining for Estimating Cover Management Factor of Universal Soil Loss Equation

    Science.gov (United States)

    Tsai, F.; Lin, T. C.; Chiang, S. H.; Chen, W. W.

    2016-12-01

    Universal Soil Loss Equation (USLE) is a widely used mathematical model that describes long-term soil erosion processes. Among the six different soil erosion risk factors of USLE, the cover-management factor (C-factor) is related to land-cover/land-use. The value of C-factor ranges from 0.001 to 1, so it alone might cause a thousandfold difference in a soil erosion analysis using USLE. The traditional methods for the estimation of USLE C-factor include in situ experiments, soil physical parameter models, USLE look-up tables with land use maps, and regression models between vegetation indices and C-factors. However, these methods are either difficult or too expensive to implement in large areas. In addition, the values of C-factor obtained using these methods can not be updated frequently, either. To address this issue, this research developed a spatial data mining approach to estimate the values of C-factor with assorted spatial datasets for a multi-temporal (2004 to 2008) annual soil loss analysis of a reservoir watershed in northern Taiwan. The idea is to establish the relationship between the USLE C-factor and spatial data consisting of vegetation indices and texture features extracted from satellite images, soil and geology attributes, digital elevation model, road and river distribution etc. A decision tree classifier was used to rank influential conditional attributes in the preliminary data mining. Then, factor simplification and separation were considered to optimize the model and the random forest classifier was used to analyze 9 simplified factor groups. Experimental results indicate that the overall accuracy of the data mining model is about 79% with a kappa value of 0.76. The estimated soil erosion amounts in 2004-2008 according to the data mining results are about 50.39 - 74.57 ton/ha-year after applying the sediment delivery ratio and correction coefficient. Comparing with estimations calculated with C-factors from look-up tables, the soil erosion

  8. Transfer factors of polonium from soil to parsley and mint.

    Science.gov (United States)

    Al-Masri, M S; Al-Hamwi, A; Eadan, Z; Amin, Y

    2010-12-01

    Transfer factors of (210)Po from soil to parsley and mint have been determined. Artificial polonium isotope ((208)Po) was used as a tracer to determine transfer factor of Po from soil to plant in pot experiments. Two plant growing systems were used for this study namely, an outdoor system and a sheltered system by a polyethylene tent. (208)Po and (210)Po were determined in soil and different parts of the studied plants (stem and leaf), using alpha spectroscopy. The results have shown that there was a clear uptake of (208)Po by roots to leaves and stems of both plants. Higher values of transfer factors using the (210)Po activity concentrations than the (208)Po activity concentration were observed. Transfer factors of (210)Po from soil to parsley varied between 20 × 10⁻² and 50 × 10⁻² and 22 × 10⁻³ and 67 × 10⁻³ in mint, while (208)Po transfer factors varied between 4 × 10⁻² and 12 × 10⁻² for parsley and 10 × 10⁻² and 22 × 10⁻² in mint. Transfer factors of Po were higher in those plants grown in the sheltered system than in the open system; about 75% of Po was transferred from atmosphere to parsley parts using the two systems. Ratios of transferred Po from soil to mint stem and leaf in the sheltered system were higher by 2 times from those in the open system. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Transfer factors of Polonium from soil to parsley and mint

    Energy Technology Data Exchange (ETDEWEB)

    Al-Masri, M.S., E-mail: prscientific@aec.org.s [Department of Protection and Safety, Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic); Al-Hamwi, A. [Department of Protection and Safety, Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic); Eadan, Z. [Physics Department, Damascus University (Syrian Arab Republic); Amin, Y. [Department of Protection and Safety, Atomic Energy Commission of Syria, Damascus, P.O. Box 6091 (Syrian Arab Republic)

    2010-12-15

    Transfer factors of {sup 210}Po from soil to parsley and mint have been determined. Artificial polonium isotope ({sup 208}Po) was used as a tracer to determine transfer factor of Po from soil to plant in pot experiments. Two plant growing systems were used for this study namely, an outdoor system and a sheltered system by a polyethylene tent. {sup 208}Po and {sup 210}Po were determined in soil and different parts of the studied plants (stem and leaf), using alpha spectroscopy. The results have shown that there was a clear uptake of {sup 208}Po by roots to leaves and stems of both plants. Higher values of transfer factors using the {sup 210}Po activity concentrations than the {sup 208}Po activity concentration were observed. Transfer factors of {sup 210}Po from soil to parsley varied between 20 x 10{sup -2} and 50 x 10{sup -2} and 22 x 10{sup -3} and 67 x 10{sup -3} in mint, while {sup 208}Po transfer factors varied between 4 x 10{sup -2} and 12 x 10{sup -2} for parsley and 10 x 10{sup -2} and 22 x 10{sup -2} in mint. Transfer factors of Po were higher in those plants grown in the sheltered system than in the open system; about 75% of Po was transferred from atmosphere to parsley parts using the two systems. Ratios of transferred Po from soil to mint stem and leaf in the sheltered system were higher by 2 times from those in the open system.

  10. Carbon footprint of milk from sheep farming systems in northern Spain including soil carbon sequestration in grasslands

    DEFF Research Database (Denmark)

    Batalla, Inma M.; Knudsen, Marie Trydeman; Mogensen, Lisbeth

    2015-01-01

    The link between climate change and livestock production has made carbon footprint based on life cycle assessment a world-wide indicator to assess and communicate the amount of greenhouse gases emitted per unit of product. Nevertheless, the majority of studies have not included soil carbon seques...

  11. 29 CFR 780.110 - Operations included in “cultivation and tillage of the soil.”

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Operations included in âcultivation and tillage of the soil.â 780.110 Section 780.110 Labor Regulations Relating to Labor (Continued) WAGE AND HOUR DIVISION, DEPARTMENT OF LABOR STATEMENTS OF GENERAL POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS EXEMPTIONS APPLICABLE TO AGRICULTURE, PROCESSIN...

  12. Urban soils as hotspots of anthropogenic carbon accumulation: Review of stocks, mechanisms and factors

    Science.gov (United States)

    Vasenev, Viacheslav; Kuzyakov, Yakov

    2017-04-01

    Urban soils and cultural layers accumulate carbon (C) over centuries and consequently large C stocks are sequestered below the cities. These C stocks as well as the full range of processes and mechanisms leading to high C accumulation in urban soils remain unknown. We collected data on organic (SOC), inorganic (SOC) and black (pyrogenic) (BC) C content in urban and natural soils from 100 papers based on Scopus and Web-of-Knowledge databases. The yielded database includes 770 values on SOC, SIC and BC stocks from 118 cities worldwide. The collected data were analyzed considering the effects of climatic conditions and urban-specific factors: city size, age and functional zoning. For the whole range of climatic conditions, the C contents in urban soils were 1.5-3 times higher than in respective natural soils. This higher C content and much deeper C accumulation in urban soils resulted in 3 to 5 times higher C stocks compared to natural soils. Urban SOC stocks were positively correlated with latitude, whereas SIC stocks were less affected by climate. The city size and age were the main factors controlling intra-city variability of C stocks with higher stocks in small cities compared to megapolises and in medieval compared to new cities. The inter-city variability of C stocks was dominated by functional zoning: large SOC and N stocks in residential areas and large SIC and BC stocks in industrial zones and roadsides were similar for all climates and for cities of different size and age. Substantial stocks of SOC, SIC and N were sequestered for long-term in the subsoils and cultural layers of the sealed soils, which underline the importance of these 'hidden' stocks for C assessments. Typical and specific for urban soils is that the anthropogenic factor overshadows the other five factors of soil formation. Substantial C stocks in urban soils and cultural layers result from specific mechanisms of C accumulation in cities: i) large and long-term C inputs from outside the

  13. An impedance function approach for soil-structure interaction analyses including structure-to-structure interaction effects

    International Nuclear Information System (INIS)

    Gantayat, A.; Kamil, H.

    1981-01-01

    The dynamic soil-structure and structure-to-structure interaction effects may be determined in one of the two ways: by modeling the entire soil-structure system by a finite-element model, or by using a frequency-dependent (or frequency-independent) impedance function approach. In seismic design of nuclear power plant structures, the normal practice is to use the first approach because of its simplicity and easy availability of computer codes to perform such analyses. However, in the finite-element approach, because of the size and cost restrictions, the three-dimensional behavior of the entire soil-structure system and the radiation damping in soil are only approximately included by using a two-dimensional finite-element mesh. In using the impedance function approach, the soil-structure analyses can be performed in four steps: (a) determination of the dynamic properties of the fixed base superstructure, (b) determination of foundation and structure impedance matrices and input motions, (c) evaluation of foundation motion, (d) analysis of the fixed base superstructure using computed foundation motion. (orig./RW)

  14. Soil-to-plant transfer factors for radiocaesium measured in different soil types in the Czech Republic

    International Nuclear Information System (INIS)

    Tecl, J.; Mirchi, R.; Malatova, I.; Peskova, I.; Schlesingerova, E.

    2001-01-01

    This study was perform in frame of the SAVEC project (SAVEC = Spatial Analysis of Vulnerable Ecosystems in Central Europe; European Union project). The aim of the SAVEC project was to develop a user-friendly software package that will allow the identification of areas vulnerable or resilient to radiocesium deposition in the Central European countries: Poland, Hungary and the Czech Republic. The software package will incorporate a semi- mechanistic soil-to-plant transfer model which uses commonly measured soil properties to estimate the dynamic behaviour of deposited radiocesium. This model was developed for the European Commission IV th Framework programme Spatial Analysis of Vulnerable Ecosystems (SAVE) project. In the SAVEC software package, spatially variable data (including 137 CS deposition, soil property , agricultural production and dietary data) can be used to assess the consequences of the deposition in the three Central European countries following nuclear accidents. The SAVEC project collates data of sufficient resolution specific to Poland, Hungary and the Czech Republic for integration within the SAVE-IT software package to allow the identification of areas and population groups that may be vulnerable to radiocesium deposition. From this viewpoint the samples of soil and vegetation were collected (1999 and 2000; the locations of the sampling places are in Fig. 1.) in which the content of 137 CS by semiconductor gamma spectrometry were determined. The mass activity of 137 CS were used for calculation of soil-to-plant transfer factors. (authors)

  15. Soil to plant transfer factor of radiocesium by pot experiment

    International Nuclear Information System (INIS)

    Jalil, A.; Rahman, M.M.; Koddus, A.; Chand, M.M.; Zaman, M.A.; Ahmad, G.U.

    2002-01-01

    This paper deals with the soil to plant transfer factor (TF) of radiocesium (Cs 137 ) considered to be an important parameter while calculating radiological doses due to the potential release of radionuclides into the environment. In the present work, TF values were measured for the main foodstuffs in Bangladesh such as leafy vegetables (Lalshak, Palangshak), Ladyfinger, Radish, Potato, Potato Plant, Paddy, Paddy plant, Grass, Ginger, Ginger plant, Turmeric, and Turmeric plant by pot experiments grown in the AERE soil. Soil characteristics have also been investigated to assist the measured values of the corresponding radionuclide. TF values of the leafy parts and products of the corresponding plants were found in the range of 2.02x10 -1 to 1.8x10 -2 , which are reasonably comparable with the value found in the literature. It has been observed that the TF values in the leafy part of the plants are higher than the products. (author)

  16. Intestinal parasites in children and soil from Turbaco, Colombia and associated risk factors.

    Science.gov (United States)

    Villafañe-Ferrer, Lucy M; Pinilla-Pérez, Mavianis

    2016-02-01

    Objective To determine the frequency of intestinal parasites in children and soil from Turbaco- Colombia and associated risks factors. Methods Analytical study in which 390 children between 2 and 12 years old from 10 neighborhoods of Turbaco were included, whose legal representatives gave informed consent. Three serial samples of feces and 10 soil samples were processed. Risk factors were determined through an interview. Physicochemical and structural characteristics of soils were also evaluated. Results Parasites were found in 30.5 % of children. 162 parasites were observed; the most frequent protozoan was Endolimax nana (30.3 %) and in terms of helminthes, the most frequent was Ascaris lumbricoides (4.9 %). No statistical association between age or sex and intestinal parasites (p>0.05) or between risk factors and intestinal parasites (p>0.05) was found. Low frequencies of intestinal parasites were encountered in soil samples, being more common Entamoeba spp., Giardia spp., and Ascaris lumbricoides. Neighborhoods of Turbaco had sandy dry soil with low content of ions, low conductivity and low organic matter. Conclusion This study showed a low frequency of intestinal parasites in feces and soils. Despite this, pathogenic parasites were found which can affect the health of the population. Besides this, a high percentage of intestinal parasites that are transmitted through feces were detected indicating fecal contamination and low level of hygiene.

  17. Limiting Factors for Agricultural Production and Differentiation of Soil Management in Romania

    Science.gov (United States)

    Ioana Moraru, Paula; Rusu, Teodor; Bogdan, Ileana; Ioan Pop, Adrian; Pop, Horia

    2017-04-01

    Romania's land area is 23,839,100 ha; 0.16% of the world's surface. Worldwide, Romania is ranked #83 for areal extent, and it consitutes 4.81% of the Europe's surface (ranked #12). Romania has 14,856,800 ha of agricultural land which represents 62.3% of the total surface; 0.65 ha per capita. At the national level, 72.5% and 27.5% of soils in Romania can be broadly classed as very poor and good/very good, respectively, based on intrinsic soil characteristics, climate, topography, and ground water. Romania has a specific geographical situation, namely: i) Romanian territory is located in the southeast portion of Central Europe at the cross roads of several high and low pressure centers that form regularly at the borders. The influence of these air masses is altered by the presence in the central regions of the Carpathian mountain chain resulting in a diverse climate with average annual rain fall amounts between 350 to 1,400 mm and average annual temperatures between 2 and 11.5°C. ii) At the national level, almost all soils in the international classification system are present in Romania; each soil type having specific properties and characteristics. iii) On approximately 12.5 million ha (7.5 million ha arable), soil fertility is adversely affected by erosion, acidity, low humus content, extreme texture (clay, sand), excessive moisture, chemical pollution etc. These natural and anthropogenic factors dramatically influence agricultural production. Furthermore, soil, climate, topography, etc. vary widely not only across the country, but also on smaller scales, even across fields within the same farm. In Steppe zone limitative climatic factors, which require differentiation towards soil management use, include: long periods of drought, high temperatures, high frequency winds (wind erosion in area of sands), low relative air humidity, and harsh frosts during winter. Negative phenomena most commonly encountered in this area are salinization, excess water, temporary

  18. Soil-to-potato transfer factors of elements

    International Nuclear Information System (INIS)

    Tsukada, Hirofumi; Watabe, Teruhisa.

    1996-01-01

    Transfer factors (TFs) of stable elements from soil to potato were determined for 26 pairs of samples which were collected at different sites in Aomori prefecture, Japan. The concentrations of 31 elements in both soil and potato samples were determined by neutron activation analysis. Several of these elements were divided into two groups, each having different TF characteristics. In the first group of elements, such as Cl, K, Ca, etc., an inverse correlation was seen between the TFs for each element and their concentrations in the soil. The relatively constant concentrations of these elements in potato were independent of the concentrations of the same elements in soil. However, in the second group, the TFs for other elements, such as Sc, Co and so on, in potato were independent of their concentrations in the soil. The fluctuation of TF observed in this study was smaller than that previously reported. It may be attributed to the fact that the experiment was done in a relatively narrow geographic area. In addition, the TFs for stable elements in this study were generally one to three orders of magnitude lower than those compiled for radioactive isotopes in IAEA publications. These differences should be precisely examined hereafter. (author)

  19. Evaluation of field test kits including immunoassays for the detection of contaminants in soil and water

    International Nuclear Information System (INIS)

    Waters, L.C.; Smith, R.R.; Counts, R.W.; Stewart, J.H.; Jenkins, R.A.

    1993-01-01

    Effective field test methods are needed for hazardous waste site characterization and remediation. Useful field methods should be rapid, analyte-specific, cost-effective and accurate in the concentration range at which the analyte is regulated. In this study, field test kits for polychlorinated biphenyls (PCBs), mercury, lead and nitrate were evaluated with reference to these criteria. PCBs and mercury, in soils, were analyzed by immunoassay. Ionic lead and nitrate, in water, were measured chemically using test strips. Except for lead, each analyte was measured in both spiked and actual field samples. Twenty to 40 samples per day can be analyzed with the immunoassays and even more with the strip tests. The sensitivity of the immunoassays is in the 1-3 ppM range. Nitrate was consistently detected at ≥5 ppM; lead ions at ≥20 ppM. Results obtained using these methods compared favorably with those obtained by standard laboratory methods. In addition to being useful field screening methods, these kits can be used in the laboratory to sort out negative samples and/or to define proper dilutions for positive samples requiring further analysis

  20. The importance of including dynamic soil-structure interaction into wind turbine simulation codes

    DEFF Research Database (Denmark)

    Damgaard, Mads; Andersen, Lars Vabbersgaard; Ibsen, Lars Bo

    2014-01-01

    A rigorous numerical model, describing a wind turbine structure and subsoil, may contain thousands of degrees of freedom, making the approach computationally inefficient for fast time domain analysis. In order to meet the requirements of real-time calculations, the dynamic impedance of the founda......A rigorous numerical model, describing a wind turbine structure and subsoil, may contain thousands of degrees of freedom, making the approach computationally inefficient for fast time domain analysis. In order to meet the requirements of real-time calculations, the dynamic impedance...... of the foundation from a rigorous analysis can be formulated into a so-called lumped-parameter model consisting of a few springs, dashpots and point masses which are easily implemented into aeroelastic codes. In this paper, the quality of consistent lumped-parameter models of rigid surface footings and mono piles...... is examined. The optimal order of the models is determined and implemented into the aeroelastic code HAWC2, where the dynamic response of a 5.0 MW wind turbine is evaluated. In contrast to the fore-aft vibrations, the inclusion of soil-structure interaction is shown to be critical for the side-side vibrations...

  1. Effects of environmental factors and soil properties on topographic variations of soil respiration

    OpenAIRE

    Tamai, K.

    2010-01-01

    Soil respiration rates were measured along different parts of a slope in (a) an evergreen forest with common brown forest soil and (b) a deciduous forest with immature soil. The effects of soil temperature, soil moisture and soil properties were estimated individually, and the magnitudes of these effects in the deciduous and evergreen forests were compared. In the evergreen forest with common brown forest soil, soil properties had the greatest effect on soil respiration rates, followed by soi...

  2. Relations between soil factors and herbage yields of natural ...

    African Journals Online (AJOL)

    Keywords: Cation exchange capacity; Correlation matrix; Nitrogen supplies; Root mass; Root measurements; Soil acidity; Soil variables; Soil water content; Soil water measurements; Yield measurements; nitrogen supply; ph; herbage yield; grassland; soils; productivity; soil depth; dry matter yield; grasses; water content; n; ...

  3. The early warning system of landslides and sediment runoffs using meteorological condition including rainfall-soil moisture index (Invited)

    Science.gov (United States)

    Kubota, T.; Silva, I. C.; Hasnawir, H.

    2009-12-01

    The research including observation of rain, soil moisture content and sediment discharge is conducted on a torrent in northern Kyushu whose geology consists of Paleozoic metamorphic rocks (mainly schist) and whose vegetation consists of mainly Japanese cypress and cedar. Soil depth is approximately 50cm in average and permeability k is 0.1~0.01 order. With data obtained by the observation for more than 4 years, standard rainfalls of warning and evacuation against the sudden sediment runoffs are analyzed. Then, the result was compared with the ones in Nuevo Leon Mexico (geology of schist, slate, k=0.01~0.001 order) and in southern Sulawesi Island Indonesia (volcanic geology, k=0.001~0.0001 order). Hitherto, various methods were proposed to analyze the warning critical standard for landslide disaster or large sediment discharge. In this study, we employed Hirano's element slope runoff theory, the Self Organized Criticality Assumption (SOC), and the Elementary Catastrophe Theory (ETC) to analyze the data, although the soil moisture fluctuation, meteorological condition such as upper air wind and dew point depression, the rainfall-soil moisture index provided by Japan Meteorological Agency was considered. The last one is a cutting edge technology based on the tank model calculation of soil moisture content combined with short term rainfall prediction which is a product of numerical simulation using radar image advection analysis compensated with surface rain data and with orographic rain effect. In Hirano's theory, we can describe the critical rain Rc and rain intensity Ric as following equation. Q/A/M/ cosθ = Ri ∫(r*cosθ)dt = Ri*R (1) ∴ Ric*Rc = C (2) Here, Q: sediment runoff or debris flow discharge, A: watershed area, M: function concerning with sediment deposit features on the upstream torrents or slopes (porosity, torrent bed slope gradient, sediment accumulation length and depth, cohesion), t: time, θ: torrent bed or hillside slope gradient, r: instant

  4. CS-137 transfer factors soil-plant and density of hyphae in soil of spruce forests

    International Nuclear Information System (INIS)

    Klemt, E.; Deuss, H.; Drissner, J.; Krapf, M.; Miller, R.; Zibold, G.

    1999-01-01

    Samples of soil and plants were taken at spruce stand sites in southern Baden-Wuerttemberg. Fern always had the highest aggregated Cs-137 transfer factor (T ag ) varying between 0.01 and 0.27 m 2 kg -1 . There is a tendency for higher T ag s in soils with thicker raw humus layers, lower pH, lower cation exchange capacity (CEC) in the O h horizon, and lower clay content below the organic deposit. The density of hyphae is determined by the season and its weather conditions and it usually decreases continuously from O f to top B horizon. In analyzing our data no correlation between aggregated or horizon-specific transfer factors of different plants and density of hyphae could be found. Refs. 5 (author)

  5. The influence of use-related, environmental, and managerial factors on soil loss from recreational trails

    Science.gov (United States)

    Olive, Nathaniel D.; Marion, Jeffrey L.

    2009-01-01

    Recreational uses of unsurfaced trails inevitably result in their degradation, with the type and extent of resource impact influenced by factors such as soil texture, topography, climate, trail design and maintenance, and type and amount of use. Of particular concern, the loss of soil through erosion is generally considered a significant and irreversible form of trail impact. This research investigated the influence of several use-related, environmental, and managerial factors on soil loss on recreational trails and roads at Big South Fork National River and Recreation Area, a unit of the U.S. National Park Service. Regression modeling revealed that trail position, trail slope alignment angle, grade, water drainage, and type of use are significant determinants of soil loss. The introduction of individual and groups of variables into a series of regression models provides improved understanding and insights regarding the relative influence of these variables, informing the selection of more effective trail management actions. Study results suggest that trail erosion can be minimized by avoiding “fall-line” alignments, steep grades, and valley-bottom alignments near streams, installing and maintaining adequate densities of tread drainage features, applying gravel to harden treads, and reducing horse and all-terrain vehicle use or restricting them to more resistant routes.This research also sought to develop a more efficient Variable Cross-Sectional Area method for assessing soil loss on trails. This method permitted incorporation of CSA measures in a representative sampling scheme applied to a large (24%) sample of the park's 526 km trail system. The variety of soil loss measures derived from the Variable CSA method, including extrapolated trail-wide soil loss estimates, permit an objective quantification of soil erosion on recreational trails and roads. Such data support relational analyses to increase understanding of trail degradation, and long

  6. The influence of use-related, environmental, and managerial factors on soil loss from recreational trails.

    Science.gov (United States)

    Olive, Nathaniel D; Marion, Jeffrey L

    2009-03-01

    Recreational uses of unsurfaced trails inevitably result in their degradation, with the type and extent of resource impact influenced by factors such as soil texture, topography, climate, trail design and maintenance, and type and amount of use. Of particular concern, the loss of soil through erosion is generally considered a significant and irreversible form of trail impact. This research investigated the influence of several use-related, environmental, and managerial factors on soil loss on recreational trails and roads at Big South Fork National River and Recreation Area, a unit of the U.S. National Park Service. Regression modeling revealed that trail position, trail slope alignment angle, grade, water drainage, and type of use are significant determinants of soil loss. The introduction of individual and groups of variables into a series of regression models provides improved understanding and insights regarding the relative influence of these variables, informing the selection of more effective trail management actions. Study results suggest that trail erosion can be minimized by avoiding "fall-line" alignments, steep grades, and valley-bottom alignments near streams, installing and maintaining adequate densities of tread drainage features, applying gravel to harden treads, and reducing horse and all-terrain vehicle use or restricting them to more resistant routes. This research also sought to develop a more efficient Variable Cross-Sectional Area method for assessing soil loss on trails. This method permitted incorporation of CSA measures in a representative sampling scheme applied to a large (24%) sample of the park's 526 km trail system. The variety of soil loss measures derived from the Variable CSA method, including extrapolated trail-wide soil loss estimates, permit an objective quantification of soil erosion on recreational trails and roads. Such data support relational analyses to increase understanding of trail degradation, and long-term monitoring of

  7. Regional analysis of groundwater phosphate concentrations under acidic sandy soils: Edaphic factors and water table strongly mediate the soil P-groundwater P relation.

    Science.gov (United States)

    Mabilde, Lisa; De Neve, Stefaan; Sleutel, Steven

    2017-12-01

    Historic long-term P application to sandy soils in NW-Europe has resulted in abundant sorption, saturation and eventually leaching of P from soil to the groundwater. Although many studies recognize the control of site-specific factors like soil texture and phosphate saturation degree (PSD), the regional-scaled relevance of effects exerted by single factors controlling P leaching is unclear. Very large observational datasets of soil and groundwater P content are furthermore required to reveal indirect controls of soil traits through mediating soil variables. We explored co-variation of phreatic groundwater orthophosphate (o-P) concentration and soil factors in sandy soils in Flanders, Belgium. Correlation analyses were complemented with an exploratory model derived using 'path analysis'. Data of oxalate-extractable Al, Fe, P and pH KCl , phosphate sorption capacity (PSC) and PSD in three depth layers (0-30, 30-60, 60-90 cm), topsoil SOC, % clay and groundwater depth (fluctuation) were interpolated to predict soil properties on exact locations of a very extensive net of groundwater monitoring wells. The mean PSD was only poorly correlated to groundwater o-P concentration, indicating the overriding control of other factors in the transport of P to the groundwater. A significant (P soil pH and groundwater table depth than by PSD indicates the likely oversimplification of the latter index to measure the long-term potential risk of P leaching. Accounting for controls on leaching not included in PSD via an alternative index, however, seems problematic as in Flanders for example groundwater o-P turned out to be higher in finer textured soils or soils with higher pedogenic Fe content, probably because of their lower pedogenic Al content and higher soil pH. Path analysis of extensive soil and groundwater datasets seems a viable way to identify prime local determinants of soil P leaching and could be further on used for 'ground-truthing' more complex P-migration simulation

  8. Identification of factors influencing the restoration of cyanobacteria-dominated biological soil crusts.

    Directory of Open Access Journals (Sweden)

    Chongfeng Bu

    Full Text Available Biological soil crusts (BSCs cover >35% of the Earth's land area and contribute to important ecological functions in arid and semiarid ecosystems, including erosion reduction, hydrological cycling, and nutrient cycling. Artificial rapid cultivation of BSCs can provide a novel alternative to traditional biological methods for controlling soil and water loss such as the planting of trees, shrubs, and grasses. At present, little is known regarding the cultivation of BSCs in the field due to lack of knowledge regarding the influencing factors that control BSCs growth. Thus, we determined the effects of various environmental factors (shade; watering; N, P, K, and Ca concentrations on the growth of cyanobacteria-dominated BSCs from the Sonoran Desert in the southwestern United States. The soil surface changes and chlorophyll a concentrations were used as proxies of BSC growth and development. After 4 months, five factors were found to impact BSC growth with the following order of importance: NH4NO3 ≈ watering frequency>shading>CaCO3 ≈ KH2PO4. The soil water content was the primary positive factor affecting BSC growth, and BSCs that were watered every 5 days harbored greater biomass than those watered every 10 days. Groups that received NH4NO3 consistently exhibited poor growth, suggesting that fixed N amendment may suppress BSC growth. The effect of shading on the BSC biomass was inconsistent and depended on many factors including the soil water content and availability of nutrients. KH2PO4 and CaCO3 had nonsignificant effects on BSC growth. Collectively, our results indicate that the rapid restoration of BSCs can be controlled and realized by artificial "broadcasting" cultivation through the optimization of environmental factors.

  9. On the use of risk-informed regulation including organizational factors

    International Nuclear Information System (INIS)

    Gibelli, S.M.O.; Alvarenga, M.A.B.

    1998-01-01

    Risk-Informed Regulation (RIR) can be applied by using Probabilistic Safety Assessment (PSA) as a basic tool. Traditionally, PSA methodology encompasses the calculation of failure probabilities of Structures, Systems and Components (SSCs) and direct associated human errors. However, there are indirect causes related to human failures, associated with Organizational Factors, which are normally not included in fault trees, that may influence plant risk evaluation. This paper discusses on possible applications of RIR and on Organizational Factors. It also presents a classification of Angra-1 NPP unresolved issues, aiming a future inclusion of these factors into a PSA calculation. (author)

  10. Denitrification potential of riparian soils in relation to multiscale spatial environmental factors: a case study of a typical watershed, China.

    Science.gov (United States)

    Wei, Jianbing; Feng, Hao; Cheng, Quanguo; Gao, Shiqian; Liu, Haiyan

    2017-02-01

    The objective of this study was to test the hypothesis that environmental regulators of riparian zone soil denitrification potential differ according to spatial scale within a watershed; consequently, a second objective was to provide spatial strategies for conserving and restoring the purification function of runoff in riparian ecosystems. The results show that soil denitrification in riparian zones was more heterogeneous at the profile scale than at the cross-section and landscape scales. At the profile scale, biogeochemical factors (including soil total organic carbon, total nitrogen, and nitrate-nitrogen) were the major direct regulators of the spatial distribution of soil denitrification enzyme activity (DEA). At the cross-section scale, factors included distance from river bank and vegetation density, while landscape-scale factors, including topographic index, elevation, and land use types, indirectly regulated the spatial distribution of DEA. At the profile scale, soil DEA was greatest in the upper soil layers. At the cross-section scale, maximum soil DEA occurred in the mid-part of the riparian zone. At the landscape scale, soil DEA showed an increasing trend towards downstream sites, except for those in urbanized areas.

  11. Soil

    International Nuclear Information System (INIS)

    Freudenschuss, A.; Huber, S.; Riss, A.; Schwarz, S.; Tulipan, M.

    2002-01-01

    Environmental soil surveys in each province of Austria have been performed, soils of about 5,000 sites were described and analyzed for nutrients and pollutants, the majority of these data are recorded in the soil information system of Austria (BORIS) soil database, http://www.ubavie.gv.at/umweltsituation/boden/boris), which also contains a soil map of Austria, data from 30 specific investigations mainly in areas with industry and results from the Austria - wide cesium investigation. With respect to the environmental state of soils a short discussion is given, including two geographical charts, one showing which sites have soil data (2001) and the other the cadmium distribution in top soils according land use (forest, grassland, arable land, others). Information related to the soil erosion, Corine land cover (Europe-wide land cover database), evaluation of pollutants in soils (reference values of As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Se, Pb, Tl, Va, Zn, AOX, PAH, PCB, PCDD/pcdf, dioxin), and relevant Austrian and European standards and regulations is provided. Figs. 2, Tables 4. (nevyjel)

  12. Factors influencing the chemical extractability of 241Am from a contaminated soil

    International Nuclear Information System (INIS)

    Nishita, H.; Hamilton, M.

    1976-01-01

    Factors influencing the extractability of 241 Am from an artificially contaminated soil were investigated. This was done with an equilibrium batch technique using CH 3 COOH-NH 4 OH and HNO 3 -NaOH extracting systems. The influence of several soil components was determined indirectly by selectively removing them from the soil. The effect of water- and HCl-soluble salts and organic matter on 241 Am extractability was small. The most marked effect was due to the soil organic fraction that was not water- or HCl-soluble. This organic fraction was influential under both low and high pH conditions, but its influence was particularly marked under low pH conditions. The free iron-oxides had an appreciable effect under low pH conditions, but no observable effect in the high pH range. Though to a lesser extent, the free silica and alumina, amorphous alumino-silicate, and possibly residual organic matter also showed some influence. These results provide some implications on the conditions that influence the movement of 241 Am in soils and its availability to plants. A review of the literature on the behavior of Am in soils is included

  13. [Analysis of soil respiration and influence factors in wheat farmland under conservation tillage in southwest hilly region].

    Science.gov (United States)

    Zhang, Sai; Zhang, Xiao-Yu; Wang, Long-Chang; Luo, Hai-Xiu; Zhou, Hang-Fei; Ma, Zhong-Lian; Zhang, Cui-Wei

    2013-07-01

    In order to investigate the effect of conservation tillage on soil respiration in dry cropping farmland in southwest purple hilly region, the LI6400-09 respiratory chamber was adopted in the experiment conducted in the experimental field in Southwest University in Beibei, Chongqing. The respiration and the hydrothermal and biotic factors of soil were measured and analyzed during the growth period of wheat in the triple intercropping system of wheat/maize/soybean. There were four treatments including T (traditional tillage), R (ridge tillage), TS (traditional tillage + straw mulching) and RS (ridge tillage + straw mulching), which were all in triplicates. The results indicated that the soil respiration rate changed in the range of 1.100-2.508 micromol x (m2 x s)(-1) during the reproductive growth stage of wheat. There were significant differences in soil respiration rate among different treatments, which could be ranked as RS > R > TS > T. The soil temperature in the 10cm layer was ranked as T > R > TS > RS. The relationship between soil respiration and soil temperature fitted well with an exponential function, in which the Q10 values were 1.25, 1.20, 1.31 and 1.26, respectively. The soil moisture in the 5cm layer was ranked as TS > RS > T > R. The best fitting model between soil moisture and soil respiration was a parabolic curve, indicating the presence of soil moisture with the strongest soil respiration. The response threshold of wheat to soil moisture was 14.80%-17.47% during the reproductive stage. The dominant groups of soil animals were Collembola and Acarina, which were correlated with soil respiration to some extent. The correlation was high in the treatments T and R, ranged from 0.669-0.921, whereas there was no remarkable correlation in the other treatments.

  14. Interrelationships of metal transfer factor under wastewater reuse and soil pollution.

    Science.gov (United States)

    Papaioannou, D; Kalavrouziotis, I K; Koukoulakis, P H; Papadopoulos, F; Psoma, P

    2018-06-15

    The transfer of heavy metals under soil pollution wastewater reuse was studied in a Greenhouse experiment using a randomized block design, including 6 treatments of heavy metals mixtures composed of Zn, Mn, Cd, Co, Cu, Cr, Ni, and Pb, where each metal was taking part in the mixture with 0, 10, 20, 30, 40, 50 mg/kg respectively, in four replications. The Beta vulgaris L (beet) was used as a test plant. It was found that the metal transfer factors were statistically significantly related to the: (i) DTPA extractable soil metals, (ii) the soil pollution level as assessed by the pollution indices, (iii) the soil pH, (iv) the beet dry matter yield and (v) the interactions between the heavy metals in the soil. It was concluded that the Transfer Factor is subjected to multifactor effects and its real nature is complex, and there is a strong need for further study for the understanding of its role in metal-plant relationships. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Factors Affecting Soil Quality Maintenance In Northern Katsina State

    African Journals Online (AJOL)

    programs or scientifically based soil management strategies. Soil quality ... envelopment analysis techniques in the reconciliation of two ..... integrated plant production and environmental quality. In ..... Handbook of Soil Science. (Ed). Sumner ...

  16. The effect of Fe, Mn, Ni and Pb Load on Soil and its enrichment factor ratios in different soil grain size fractions as an Indicator for soil pollution

    International Nuclear Information System (INIS)

    Rabie, F.H.; Abdel-Sabour, M.F.

    2000-01-01

    An industrial area north of greater Cairo was selected to investigate the impact of intensive industrial activities on soil characteristics and Fe, Mn, Ni and Pb total content. The studied area was divided to six sectors according to its source of irrigation water and/or probability of pollution. Sixteen soil profiles were dug and soil samples were taken, air dried, fractionated to different grain size fractions, then total heavy metals (Fe, Mn, Ni and Pb) were determined using ICP technique. The enrichment factor for each metal for each soil fraction/soil layer was estimated and discussed. The highest EF ratios in the clay fraction was mainly with Pb which indicated the industrial impact on the soil. In case of sand fraction, Mn was the highest always compared to other studied metals. Concerning silt fraction, a varied accumulation of Fe, Mn, and Pb was observed with soil depth and different soil profiles

  17. Fine scale spatial variability of microbial pesticide degradation in soil: scales, controlling factors, and implications

    DEFF Research Database (Denmark)

    Dechesne, Arnaud; Badawi, N.; Aamand, Jens

    2014-01-01

    across pesticide classes: they include some soil characteristics (pH) and some agricultural management practices (pesticide application, tillage), while other potential controlling factors have more conflicting effects depending on the site or the pesticide. Evidence demonstrating the importance......Pesticide biodegradation is a soil microbial function of critical importance for modern agriculture and its environmental impact. While it was once assumed that this activity was homogeneously distributed at the field scale, mounting evidence indicates that this is rarely the case. Here, we...... critically examine the literature on spatial variability of pesticide biodegradation in agricultural soil. We discuss the motivations, methods, and main findings of the primary literature. We found significant diversity in the approaches used to describe and quantify spatial heterogeneity, which complicates...

  18. Effects of environmental factors and soil properties on topographic variations of soil respiration

    Directory of Open Access Journals (Sweden)

    K. Tamai

    2010-03-01

    Full Text Available Soil respiration rates were measured along different parts of a slope in (a an evergreen forest with common brown forest soil and (b a deciduous forest with immature soil. The effects of soil temperature, soil moisture and soil properties were estimated individually, and the magnitudes of these effects in the deciduous and evergreen forests were compared. In the evergreen forest with common brown forest soil, soil properties had the greatest effect on soil respiration rates, followed by soil moisture and soil temperature. These results may be explained by the fact that different soil properties matured within different environments. It can be argued that the low soil respiration rates in the low parts of the slope in the evergreen forest resulted from soil properties and not from wet soil conditions. In the deciduous forest, soil respiration rates were more strongly affected by soil moisture and soil temperature than by soil properties. These effects were likely due to the immaturity of the forest soil.

  19. 137Cs Transfer Factor from Latosol Soil to Swamp Gabbages (Ipomea Reptans Poir)

    International Nuclear Information System (INIS)

    Leli-Nirwani; Yurfida; Buchori

    2001-01-01

    A study of 137 Cs transfer factor from Latosol soil to swamp cabbages plant has been conducted using pot treatment system with complete random design. The aim of the research is to determine transfer factor of 137 Cs from latosol soil to swamp cabbages plant. Cs-137 concentration administered was 7.5287 kBq/pot. The number of swamp cabbages planted in 137 Cs treated soil and in cannot soil respectively was 12 pots filled with 1 kg soil/pot. After harvest, the weight of dried plant was measured. Transfer factor was determined according to the accumulation of 137 Cs concentration in swamp cabbages and soil and counted using Spectrometer Gamma. It was found that is a significant difference between 137 Cs concentration in swamp cabbages planted inthe treated soil and that of control soil. Transfer factor ranges between 0.02 and 0.13 with the averageof 0.08. (author)

  20. Empirical Site Amplification Factors Incorporating Soil Nonlinearity in Taiwan

    Science.gov (United States)

    Kuo, C. H.; Chung, C. H.; Che-Min, L.; Huang, J. Y.; Wen, K. L.

    2017-12-01

    Characteristics of site amplifications caused by both crustal and subduction earthquakes are important in Taiwan. For example, seismic waves were amplified and led to significant building damages in the Taipei Basin by the 1986 Hualien offshore (subduction interface) and the 1999 Chi-Chi earthquakes (crustal), for which the epicentral distances were about 100 km. To understand local site amplifications in Taiwan, empirical site amplification factors for horizontal ground motions are studied using recently constructed strong motion and site databases for the free-field TSMIP stations in Taiwan. Records of large magnitude earthquakes of ML larger than six from 1994 to 2014 were selected for this study. Site amplification factors at site conditions with Vs30 of 120 m/s to 1500 m/s and base accelerations up to 0.7g were inferred from intensity ratios of station pairs within specific distances. The reference site condition is assumed as Vs30 of 760 m/s (B/C boundary). Preliminary results indicate: 1. Soil nonlinearity is more obviously at short periods (PGA, Sa0.3) than long periods (PGV, Sa1.0). 2. Soil nonlinearity is significant for stations belong to site classes of B, C, D, and E in Taiwan. 3. Effect of station-pair distance is seen at short periods (PGA and Sa0.3). 4. No significant different is found in site amplifications of crustal and subduction earthquakes. The result could be a reference for the Fa and Fv in Taiwan's building code.

  1. Confounding factors in determining causal soil moisture-precipitation feedback

    Science.gov (United States)

    Tuttle, Samuel E.; Salvucci, Guido D.

    2017-07-01

    Identification of causal links in the land-atmosphere system is important for construction and testing of land surface and general circulation models. However, the land and atmosphere are highly coupled and linked by a vast number of complex, interdependent processes. Statistical methods, such as Granger causality, can help to identify feedbacks from observational data, independent of the different parameterizations of physical processes and spatiotemporal resolution effects that influence feedbacks in models. However, statistical causal identification methods can easily be misapplied, leading to erroneous conclusions about feedback strength and sign. Here, we discuss three factors that must be accounted for in determination of causal soil moisture-precipitation feedback in observations and model output: seasonal and interannual variability, precipitation persistence, and endogeneity. The effect of neglecting these factors is demonstrated in simulated and observational data. The results show that long-timescale variability and precipitation persistence can have a substantial effect on detected soil moisture-precipitation feedback strength, while endogeneity has a smaller effect that is often masked by measurement error and thus is more likely to be an issue when analyzing model data or highly accurate observational data.

  2. Factors affecting the determination of the isotopically exchangeable phosphorus in soils

    International Nuclear Information System (INIS)

    Morales, L.E.M.

    1981-06-01

    In order to evaluate the factors that affect the determination of the isotopically exchangeable phosphorus in soils (L value), various greenhouse experiments were carried out. The following factors were considered: carrier level; plant species; harvest time; nitrogen doses; nitrogen sources; culture conditions and soil type. A radioactive solution with an activity level of approximately 10 μCi 32 p/3 kg soil with different carrier levels was located in layers or mixed completely with the soil depending upon the experiment. (author)

  3. The use of plants, including trees, to remediate oil-contaminated soils: a review and empirical study

    OpenAIRE

    Yan, Lijuan

    2012-01-01

    Soil contamination can result in soil degradation, bring great loss to agricultural production and pose threat to human health. Many of the soil contaminants are petroleum hydrocarbons (PHCs) derived from crude oil or refined petroleum products. Phytoremediation which relies on plants and their associated microorganisms to remove contaminants is cost-effective and applicable to treat a wide variety of soil contaminants. Besides trees, herbaceous plants are widely and effectively used in the r...

  4. [Advance in researches on vegetation cover and management factor in the soil erosion prediction model].

    Science.gov (United States)

    Zhang, Yan; Yuan, Jianping; Liu, Baoyuan

    2002-08-01

    Vegetation cover and land management are the main limiting factors of soil erosion, and quantitative evaluation on the effect of different vegetation on soil erosion is essential to land use and soil conservation planning. The vegetation cover and management factor (C) in the universal soil loss equation (USLE) is an index to evaluate this effect, which has been studied deeply and used widely. However, the C factor study is insufficient in China. In order to strengthen the research of C factor, this paper reviewed the developing progress of C factor, and compared the methods of estimating C value in different USLE versions. The relative studies in China were also summarized from the aspects of vegetation canopy coverage, soil surface cover, and root density. Three problems in C factor study were pointed out. The authors suggested that cropland C factor research should be furthered, and its methodology should be unified in China to represent reliable C values for soil loss prediction and conservation planning.

  5. Factors of influencing dissolved organic carbon stabilization in two cambic forest soils with contrasting soil-forming processes

    Science.gov (United States)

    Kawasaki, M.; Ohte, N.; Asano, Y.; Uchida, T.; Kabeya, N.; Kim, S.

    2004-05-01

    Stabilization of Dissolved Organic Carbon (DOC) in forest soil is a major process of soil organic carbon formation. However, the factors influencing DOC stabilization are poorly understood. To clarify the factors that affect the stabilization of DOC in forest soil mantle, we measured DOC concentrations and soil properties which were DOC adsorption efficiency at two adjacent cambic forest soils with contrasting forest management histories in Tanakami Mountains, central Japan. Matsuzawa was devastated about 1,200 years ago by excessive timber use and remained denuded for a long period. Hillside restoration and reforestation work have been carried out over the last 100 years and soil loss has been reduced. Fudoji is covered with undisturbed forest (mixed stands of cypress and oaks) with developed forest soils (more than 2,600 years old). There was no apparent seasonal variation in DOC concentration in the soil solution in either catchment. In addition, there were no significant relationships between the DOC concentration, soil temperature, and new water ratio. These results indicate that temporal variation in biological activity and rainfall-runoff process have little effect on temporal variation in DOC. The vertical variation in the DOC adsorption efficiency and DOC concentration differed between Matsuzawa and Fudoji, and the highest DOC removal rate occurred at the lowest DOC adsorption efficiency in the 0 to 10-cm soil layer at Fudoji. These results suggest that DOC removal rate is independent of DOC adsorption efficiency. Below 60 cm soil depth, DOC fluxes were constant and dissolved organic Al concentrations were little or zero in either catchment. These results suggest that abiotic precipitation of DOC is a major mechanism for stabilization of DOC. Therefore, DOC content which is able to form metal complexes may be the most important factor of influencing DOC stabilization in cambic forest soil.

  6. Policies for including disabled people in education. obstacles and facilitating factors for their implementation: Bucaramanga, 2010

    Directory of Open Access Journals (Sweden)

    Claudia P. Serrano R

    2011-07-01

    Full Text Available Objective: to explore the factors enabling or hindering the implementation of inclusive education policies for the disabled population of Bucaramanga. Methodology: a descriptive study, involving representatives from governmental agencies (EG, members of the faculty boards of educational institutions (DIE and guardians of disabled individuals (APSD. Physical, social, and political obstacles and facilitating factors that could potentially determine the implementation of these policies were analyzed. Data was collected through interviews. Results: there was a total of 2, 32, and 34 participants from the EG, DIE, and APSD groups respectively. Identified obstacles included: lack of strategies to support educational institutions, poor or limited teacher training, high tuition fees, and negative attitude towards disability. The facilitating factors included: availability of places, inclusion of this issue in the political agenda, and desire of the disabled individuals’ families to provide them with education. Discussion: These findings provide useful information for further research on this issue and show how action has been taken, as well as how urgent it is to establish a direct relationship between academia and the public sector to propose strategies for assessing and modifying these policies.

  7. Factors responsible for the patchy distribution of natural soil water repellency in Mediterranean semiarid forest

    Science.gov (United States)

    Lozano, E.; Jiménez-Pinilla, P.; Mataix-Solera, J.; González-Pérez, J. A.; García-Orenes, F.; Torres, M. P.; Arcenegui, V.; Mataix-Beneyto, J.

    2012-04-01

    H and between SOM and pH for all except for Q. rotundifolia. However, the negative correlation found between pH and persistence of WR seems to be related to soil organic matter (SOM) content for all vegetal species. Glomalin exudates from arbuscular mycorrhizal fungi in soil revealed significant differences between species. However, the first results do not point to a direct relationship between EEG content and WR but to soil mineralogy or certain components within SOM pool i.e. litter debris degradation products or specific components within the glomalin extract, as main factors affecting soil WR. Nonetheless, since some samples with the same SOM content (including some under the same vegetation cover) showed different WR persistence, complementary research including a more detailed characterization of most soil functional fractions (SOM and clays) is planned in order to elucidat the main factors influencing the presence and persistence of WR in soils under Mediterranean semiarid forest. Keywords: Water repellency, hydrophobicity, easily extractable glomalin, mycelium, arbuscular mycorrhizal fungi.

  8. Behavioral factors to include in guidelines for lifelong oral healthiness: an observational study in Japanese adults

    Directory of Open Access Journals (Sweden)

    Shimozato Miho

    2006-12-01

    Full Text Available Abstract Background The aim of this study was to determine which behavioral factors to include in guidelines for the Japanese public to achieve an acceptable level of oral healthiness. The objective was to determine the relationship between oral health related behaviors and symptoms related to oral disease and tooth loss in a Japanese adult community. Methods Oral health status and lifestyle were investigated in 777 people aged 20 years and older (390 men and 387 women. Subjects were asked to complete a postal questionnaire concerning past diet and lifestyle. The completed questionnaires were collected when they had health examinations. The 15 questions included their preference for sweets, how many between-meal snacks they usually had per day, smoking and drinking habits, presence of oral symptoms, and attitudes towards dental visits. Participants were asked about their behaviors at different stages of their life. The oral health examinations included examination of the oral cavity and teeth performed by dentists using WHO criteria. Odds ratios were calculated for all subjects, all 10 year age groups, and for subjects 30 years or older, 40 years or older, 50 years or older, and 60 years or older. Results Frequency of tooth brushing (OR = 3.98, having your own toothbrush (OR = 2.11, smoking (OR = 2.71 and bleeding gums (OR = 2.03 were significantly associated with number of retained teeth in males. Frequency of between-meal snacks was strongly associated with number of retained teeth in females (OR = 4.67. Having some hobbies (OR = 2.97, having a family dentist (OR = 2.34 and consulting a dentist as soon as symptoms occurred (OR = 1.74 were significantly associated with number of retained teeth in females. Factors that were significantly associated with tooth loss in both males and females included alcohol consumption (OR = 11.96, males, OR = 3.83, females, swollen gums (OR = 1.93, males, OR = 3.04, females and toothache (OR = 3.39, males, OR

  9. Optimum Design of Braced Steel Space Frames including Soil-Structure Interaction via Teaching-Learning-Based Optimization and Harmony Search Algorithms

    OpenAIRE

    Ayse T. Daloglu; Musa Artar; Korhan Ozgan; Ali İ. Karakas

    2018-01-01

    Optimum design of braced steel space frames including soil-structure interaction is studied by using harmony search (HS) and teaching-learning-based optimization (TLBO) algorithms. A three-parameter elastic foundation model is used to incorporate the soil-structure interaction effect. A 10-storey braced steel space frame example taken from literature is investigated according to four different bracing types for the cases with/without soil-structure interaction. X, V, Z, and eccentric V-shaped...

  10. Factors mediating the restoration of structurally degraded soils

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Moldrup, Per; Schjønning, Per

    with the ability of soils to perform these functions. The present study examines the roles of clay mineralogy, native organic matter, and exogenous organic material on the restoration of structurally degraded soils. Totally seven soils from Denmark and Ghana - five soils dominated by illites, one kaolinitic soil...... the incubation period, structural stability estimated as the amount of water-dispersible clay decreased with prevailing moisture content, and native organic matter. Also, microbial activity significantly increased with addition of exogenous organic matter. At the end of incubation, there was significant...... macroaggregation, decreased bulk density, and increased equivalent pore diameter and tortuosity (derived from measurements of soil-gas diffusivity and soil-air permeability) for all soils. Although aggregate friability was not affected by clay type, aggregate workability was highest for the kaolinitic soil...

  11. Key biogeochemical factors affecting soil carbon storage in Posidonia meadows

    KAUST Repository

    Serrano, Oscar

    2016-08-15

    Biotic and abiotic factors influence the accumulation of organic carbon (C-org) in seagrass ecosystems. We surveyed Posidonia sinuosa meadows growing in different water depths to assess the variability in the sources, stocks and accumulation rates of Corg. We show that over the last 500 years, P. sinuosa meadows closer to the upper limit of distribution (at 2-4 m depth) accumulated 3- to 4-fold higher C-org stocks (averaging 6.3 kg C-org m(-2) at 3- to 4-fold higher rates (12.8 gC(org) m(-2) yr(-1) ) compared to meadows closer to the deep limits of distribution (at 6-8 m depth; 1.8 kg C-org m(-2) and 3.6 g C-org m(-2) yr(-1) . In shallower meadows, C-org stocks were mostly derived from seagrass detritus (88% in average) compared to meadows closer to the deep limit of distribution (45% on average). In addition, soil accumulation rates and fine-grained sediment content (< 0.125 mm) in shallower meadows (2.0 mm yr(-1) and 9 %, respectively) were approximately 2-fold higher than in deeper meadows (1.2 mm yr(-1) and 5 %, respectively). The C-org stocks and accumulation rates accumulated over the last 500 years in bare sediments (0.6 kg C-org m(-2) and 1.2 g C-org m(-2) yr(-1)were 3- to 11-fold lower than in P. sinuosa meadows, while fine-grained sediment content (1 %) and seagrass detritus contribution to the Corg pool (20 %) were 8- and 3-fold lower than in Posidonia meadows, respectively. The patterns found support the hypothesis that Corg storage in seagrass soils is influenced by interactions of biological (e.g., meadow productivity, cover and density), chemical (e.g., recalcitrance of Corg stocks) and physical (e.g., hydrodynamic energy and soil accumulation rates) factors within the meadow. We conclude that there is a need to improve global estimates of seagrass carbon storage accounting for biogeochemical factors driving variability within habitats.

  12. Revised emission factors for gas engines including start/stop emissions

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Malene; Boll Illerup, J.; Birr-Petersen, K.

    2008-06-15

    Liberalisation of the electricity market has led to Danish gas engine plants increasingly converting to the spot and regulating power markets. In order to offer regulating power, plants need to be able to start and stop the engines at the plants quickly. The liberalisation causes a considerable change of operation practice of the engines e.g. less full load operation hours /year. The project provides an inventory determining the scale of the emissions during the start and stop sequence as well as proposals for engine modifications aimed at reducing start/stop emissions. This report includes calculation of emission factors as well as an inventory of total emissions and reduction potentials. (au)

  13. Soils, County-wide soils cover - an aggregation of section-wide soil coverages with additional attributes. Primary attributes include mu symbol and ID, state symbol, name, category, percolation rate and passing percentage., Published in 2008, 1:1200 (1in=100ft) scale, Sedgwick County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Soils dataset current as of 2008. County-wide soils cover - an aggregation of section-wide soil coverages with additional attributes. Primary attributes include mu...

  14. Children and adolescents' internal models of food-sharing behavior include complex evaluations of contextual factors.

    Science.gov (United States)

    Markovits, Henry; Benenson, Joyce F; Kramer, Donald L

    2003-01-01

    This study examined internal representations of food sharing in 589 children and adolescents (8-19 years of age). Questionnaires, depicting a variety of contexts in which one person was asked to share a resource with another, were used to examine participants' expectations of food-sharing behavior. Factors that were varied included the value of the resource, the relation between the two depicted actors, the quality of this relation, and gender. Results indicate that internal models of food-sharing behavior showed systematic patterns of variation, demonstrating that individuals have complex contextually based internal models at all ages, including the youngest. Examination of developmental changes in use of individual patterns is consistent with the idea that internal models reflect age-specific patterns of interactions while undergoing a process of progressive consolidation.

  15. INFLUENCE OF HEXAVALENT CHROMIUM INITIAL CONCENTRATION ON RETARDATION FACTOR AND CONTAMINANT VELOCITY IN A SOIL MEDIA

    Directory of Open Access Journals (Sweden)

    K. SHIVA PRASHANTH KUMAR

    2016-02-01

    Full Text Available Sources of soil and ground water contamination are many and include many folds of accidental spills and leaks of toxic and hazardous chemicals. Preparation of ground water contamination model needs good understanding of the behavior of contaminant transport through soil media for predicting the level of contamination of ground water in the near future at the intended site conditions. Sorption is a natural process; due to its presence, the contaminant can move slowly as compared to the ground water and hence the effects of sorption must be taken into consideration while predicting the travel time of the contaminant to reach the ground water sources. This paper discusses the results of column test studies carried out in the laboratory under controlled conditions about the spreading of contaminant (Hexavalent chromium, Cr (VI through the clay mixed red soil at two different initial concentrations (800 mg/L and 4200 mg/L. The variations of the contaminant flow velocity and retardation factor for two different initial concentrations of contaminant were brought out and discussed. The contaminant flow velocity drastically coming down for a relative concentration of 0 to 0.2 and beyond this range, the contaminant flow velocity value is decreasing in a slow rate for both the lower and higher initial contaminant concentrations tested. At the lower relative concentration, the higher retardation factor was observed and it may be due to slowly filling the available sorption sites in the soil column.

  16. The transfer factors of I, Ba, Sr, Y and Zr from soil to leafy vegetables

    International Nuclear Information System (INIS)

    Luo Daling; Li Mianfeng; Weng Senhan; Wen Guanghao; Liu Xiaowei; Zhang Cunxiang; Zhang Zeng; Yu Junyue

    1996-01-01

    The transfer factors of I, Ba, Sr, Y and Zr from soil to leafy vegetables have been determined using method of radioisotope tracers and element content analysis. The effects of growth period, size of the vegetables, contents of the isotopes in the soil and other climatic factors on the transfer factors have also been studied

  17. Evaluation of soil saturation, soil chemistry, and early spring soil and air temperatures as risk factors in yellow-cedar decline.

    Science.gov (United States)

    D.V. D' Amore; P.E. Hennon

    2006-01-01

    Yellow-cedar (Callitropsis nootkatensis (D. Don) Oerst.) is a valuable tree species that is experiencing a widespread decline and mortality in southeast Alaska. This study evaluated the relative importance of several potential risk factors associated with yellow-cedar decline: soil saturation, soil aluminum (Al) toxicity or calcium (Ca) deficiency...

  18. Fine scale spatial variability of microbial pesticide degradation in soil: scales, controlling factors, and implications

    Directory of Open Access Journals (Sweden)

    Arnaud eDechesne

    2014-12-01

    Full Text Available Pesticide biodegradation is a soil microbial function of critical importance for modern agriculture and its environmental impact. While it was once assumed that this activity was homogeneously distributed at the field scale, mounting evidence indicates that this is rarely the case. Here, we critically examine the literature on spatial variability of pesticide biodegradation in agricultural soil. We discuss the motivations, methods, and main findings of the primary literature. We found significant diversity in the approaches used to describe and quantify spatial heterogeneity, which complicates inter-studies comparisons. However, it is clear that the presence and activity of pesticide degraders is often highly spatially variable with coefficients of variation often exceeding 50% and frequently displays nonrandom spatial patterns. A few controlling factors have tentatively been identified across pesticide classes: they include some soil characteristics (pH and some agricultural management practices (pesticide application, tillage, while other potential controlling factors have more conflicting effects depending on the site or the pesticide. Evidence demonstrating the importance of spatial heterogeneity on the fate of pesticides in soil has been difficult to obtain but modelling and experimental systems that do not include soil’s full complexity reveal that this heterogeneity must be considered to improve prediction of pesticide biodegradation rates or of leaching risks. Overall, studying the spatial heterogeneity of pesticide biodegradation is a relatively new field at the interface of agronomy, microbial ecology, and geosciences and a wealth of novel data is being collected from these different disciplinary perspectives. We make suggestions on possible avenues to take full advantage of these investigations for a better understanding and prediction of the fate of pesticides in soil.

  19. Controlling factors in the dynamics of soil organic carbon from the region of Murcia

    International Nuclear Information System (INIS)

    Albaladejo, J.; Martinez-Mena, M.; Almagro, M.; Ruiz-navarro, A.; Ortiz, R.

    2009-01-01

    Sequestration and accumulation of C on the soil is a useful way to reduce the atmospheric concentration of CO 2 and to mitigate the climate change. The purpose of this study was to identify the key factors which determine the accumulation and permanence of CO on the soils of the Murcia Region. The study was arranged from data displayed on the Murcia Region Soils Map (1:100.000). The results showed that quantity of stored CO in the 30cm superficial soil is significantly different depending on soil uses, soil type, altitude and texture. One conclusion is that changes from natural vegetation to cultivated soil are the greatest cause of losses of CO of soil. The increasing of altitude and proportion of thin-silt + clay contributes to CE accumulation. In altitude, the speed of mineralization of organic materials decreases, and the thin particles stimulate the physical protection and the chemical stabilization of CO of soil. (Author) 8 refs.

  20. A constriction factor based particle swarm optimisation algorithm to solve the economic dispatch problem including losses

    Energy Technology Data Exchange (ETDEWEB)

    Young, Steven; Montakhab, Mohammad; Nouri, Hassan

    2011-07-15

    Economic dispatch (ED) is one of the most important problems to be solved in power generation as fractional percentage fuel reductions represent significant cost savings. ED wishes to optimise the power generated by each generating unit in a system in order to find the minimum operating cost at a required load demand, whilst ensuring both equality and inequality constraints are met. For the process of optimisation, a model must be created for each generating unit. The particle swarm optimisation technique is an evolutionary computation technique with one of the most powerful methods for solving global optimisation problems. The aim of this paper is to add in a constriction factor to the particle swarm optimisation algorithm (CFBPSO). Results show that the algorithm is very good at solving the ED problem and that CFBPSO must be able to work in a practical environment and so a valve point effect with transmission losses should be included in future work.

  1. Effects of different agricultural management on a stagnic Luvisol in Lower Saxony, Germany - Factors for sustainable soil protection

    Science.gov (United States)

    Lorenz, Marco; Brunotte, Joachim; Ortmeier, Berthold

    2017-04-01

    Regarding increasing pressures by global societal and climate change, for example, the assessment of the impact of land use and land management practices on land productivity, land degradation and the related decrease in sustainable food production and the provision of ecosystem services gains increasing interest. Regarding international research on land use and soil threats, main problems in agricultural land use on global scale are erosion by water and wind, soil organic matter loss, salinization, depletion of nutrients, chemical and physical deterioration, including e.g. soil compaction. When coming to soil sciences, basically soil functions are affected negatively by intensive food production and field traffic. Management based negative changes in soil functions and a suboptimal soil structure have multiple negative effects on physical, biological and chemical soil functions, like a poor water balance, air and water permeability, disturbed soil fauna, impeded root penetration etc. and in consequence on the achievable yields. The presentation deals with the multiple effects of different agricultural machinery and technologies and different agricultural soil tillage (e.g. no-till, conservation tillage, ploughing), on various soil properties of a stagnic Luvisol in Lower Saxony, Germany. These are e.g. bulk density, air capacity, saturated water permeability, changes in pore size distribution and water retention curve as well as crop yields. Furthermore results of a long term study of bulk density and total pore size on more then 20 farms in Lower Saxony since the year 1952 will be presented. Finally, key factors and first recommendations for sustainable agricultural soil protection will be derived from the results.

  2. Macroenvironmental factors including GDP per capita and physical activity in Europe.

    Science.gov (United States)

    Cameron, Adrian J; Van Stralen, Maartje M; Kunst, Anton E; Te Velde, Saskia J; Van Lenthe, Frank J; Salmon, Jo; Brug, Johannes

    2013-02-01

    Socioeconomic inequalities in physical activity at the individual level are well reported. Whether inequalities in economic development and other macroenvironmental variables between countries are also related to physical activity at the country level is comparatively unstudied. We examined the relationship between country-level data on macroenvironmental factors (gross domestic product (GDP) per capita, public sector expenditure on health, percentage living in urban areas, and cars per 1000 population) with country-level physical activity prevalence obtained from previous pan-European studies. Studies that assessed leisuretime physical activity (n = 3 studies including 27 countries in adults, n = 2 studies including 28 countries in children) and total physical activity (n = 3 studies in adults including 16 countries) were analyzed separately as were studies among adults and children. Strong and consistent positive correlations were observed between country prevalence of leisure-time physical activity and country GDP per capita in adults (average r = 0.70; all studies, P G 0.05). In multivariate analysis, country prevalence of leisure-time physical activity among adults remained associated with country GDP per capita (two of three studies) but not urbanization or educational attainment. Among school-age populations, no association was found between country GDP per capita and country prevalence of leisure-time physical activity. In those studies that assessed total physical activity (which also includes occupational and transport physical activity), no association with country GDP per capita was observed. Clear differences in national leisure-time physical activity levels throughout Europe may be a consequence of economic development. Lack of economic development of some countries in Europe may make increasing leisure-time physical activity more difficult. Further examination of the link between country GDP per capita and national physical activity levels (across

  3. Improving ecological risk assessment by including bioavailability into species sensitivity distributions: an example for plants exposed to nickel in soil

    NARCIS (Netherlands)

    Semenzin, E.; Temminghoff, E.J.M.; Marcomini, A.

    2007-01-01

    The variability of species sensitivity distribution (SSD) due to contaminant bioavailability in soil was explored by using nickel as metal of concern. SSDs of toxicity test results of Avena sativa L. originating from different soils and expressed as total content and available (0.01 M CaCl2)

  4. Bioavailability and soil-to-plant transfer factors as indicators of potentially toxic element contamination in agricultural soils

    International Nuclear Information System (INIS)

    Adamo, Paola; Iavazzo, Pietro; Albanese, Stefano; Agrelli, Diana; De Vivo, Benedetto; Lima, Annamaria

    2014-01-01

    Soil pollution in agricultural lands poses a serious threat to food safety, and suggests the need for consolidated methods providing advisory indications for soil management and crop production. In this work, the three-step extraction procedure developed by the EU Measurement and Testing Programme and two soil-to-plant transfer factors (relative to total and bioavailable concentration of elements in soil) were applied on polluted agricultural soils from southern Italy to obtain information on the retention mechanisms of metals in soils and on their level of translocation to edible vegetables. The study was carried out in the Sarno river plain of Campania, an area affected by severe environmental degradation potentially impacting the health of those consuming locally produced vegetables. Soil samples were collected in 36 locations along the two main rivers flowing into the plain. In 11 sites, lettuce plants were collected at the normal stage of consumption. According to Italian environmental law governing residential soils, and on the basis of soil background reference values for the study area, we found diffuse pollution by Be, Sn and Tl, of geogenic origin, Cr and Cu from anthropogenic sources such as tanneries and intensive agriculture, and more limited pollution by Pb, Zn and V. It was found that metals polluting soils as a result of human activities were mainly associated to residual, oxidizable and reducible phases, relatively immobile and only potentially bioavailable to plants. By contrast, the essential elements Zn and Cu showed a tendency to become more readily mobile and bioavailable as their total content in soil increased and were more easily transported to the edible parts of lettuce than other pollutants. According to our results, current soil pollution in the studied area does not affect the proportion of metals taken up by lettuce plants and there is a limited health risk incurred. - Highlights: • Soil pollution in an intensively farmed area of

  5. Bioavailability and soil-to-plant transfer factors as indicators of potentially toxic element contamination in agricultural soils

    Energy Technology Data Exchange (ETDEWEB)

    Adamo, Paola, E-mail: paola.adamo@unina.it [Dipartimento di Agraria, Università di Napoli Federico II, via Università 100, 80055 Portici (Italy); Iavazzo, Pietro [Dipartimento di Agraria, Università di Napoli Federico II, via Università 100, 80055 Portici (Italy); Albanese, Stefano [Dipartimento di Scienze della Terra, dell' Ambiente e delle Risorse, Università di Napoli Federico II, Via Mezzocannone 8, 80134 Napoli (Italy); Agrelli, Diana [Dipartimento di Agraria, Università di Napoli Federico II, via Università 100, 80055 Portici (Italy); De Vivo, Benedetto; Lima, Annamaria [Dipartimento di Scienze della Terra, dell' Ambiente e delle Risorse, Università di Napoli Federico II, Via Mezzocannone 8, 80134 Napoli (Italy)

    2014-12-01

    Soil pollution in agricultural lands poses a serious threat to food safety, and suggests the need for consolidated methods providing advisory indications for soil management and crop production. In this work, the three-step extraction procedure developed by the EU Measurement and Testing Programme and two soil-to-plant transfer factors (relative to total and bioavailable concentration of elements in soil) were applied on polluted agricultural soils from southern Italy to obtain information on the retention mechanisms of metals in soils and on their level of translocation to edible vegetables. The study was carried out in the Sarno river plain of Campania, an area affected by severe environmental degradation potentially impacting the health of those consuming locally produced vegetables. Soil samples were collected in 36 locations along the two main rivers flowing into the plain. In 11 sites, lettuce plants were collected at the normal stage of consumption. According to Italian environmental law governing residential soils, and on the basis of soil background reference values for the study area, we found diffuse pollution by Be, Sn and Tl, of geogenic origin, Cr and Cu from anthropogenic sources such as tanneries and intensive agriculture, and more limited pollution by Pb, Zn and V. It was found that metals polluting soils as a result of human activities were mainly associated to residual, oxidizable and reducible phases, relatively immobile and only potentially bioavailable to plants. By contrast, the essential elements Zn and Cu showed a tendency to become more readily mobile and bioavailable as their total content in soil increased and were more easily transported to the edible parts of lettuce than other pollutants. According to our results, current soil pollution in the studied area does not affect the proportion of metals taken up by lettuce plants and there is a limited health risk incurred. - Highlights: • Soil pollution in an intensively farmed area of

  6. Use of coal fly ash and other waste products in soil stabilization and road construction-including non-destructive testing of roadways.

    Science.gov (United States)

    2012-02-01

    An extensive laboratory testing program was performed on subgrade soils stabilized using fly ash and lime kiln dust. The laboratory : program included measurements of: compaction curves, small strain elastic moduli, resilient modulus (Mr), Briaud Com...

  7. Use of coal fly ash and other waste products in soil stabilization and road construction including non-destructive testing of roadways.

    Science.gov (United States)

    2012-06-01

    An extensive laboratory testing program was performed on subgrade soils stabilized using fly ash and : lime kiln dust. The laboratory program included measurements of: compaction curves, small strain elastic moduli, : resilient modulus (Mr), Briaud C...

  8. Geochemistry of soil around a fluoride contaminated area in Nayagarh District, Orissa, India: factor analytical appraisal.

    Science.gov (United States)

    Tripathy, S; Panigrahi, M K; Kundu, N

    2005-09-01

    Fluoride contamination in soil was studied in the vicinity of a hot spring in Nayagarh district of Orissa. Both bulk soil from 0 to 30 cm depth and profile soils from 0 to 90 cm depth were analyzed for total fluoride (F(t)) and 0.01 M CaCl(2) extractable fluoride (F(ca)), major elements, pH, EC and Organic Carbon (OC). High concentrations of both F(t) and F(ca) were observed in the area surrounding the hot spring and the village of Singhpur. Principal factor analysis (PFA) on the parameters of the bulk soils suggests that two major chemical processes due to three factors, control the soil geochemistry of the area. Factor-1 contributes 37.11% of the total variance and is strongly loaded with Al, Si, Fe, F(t)and F(ca), and explains the fluoride enrichment of the soil, whereas the second and the third factors contribute 16.6 and 12.2%, respectively and explain the controlling process of carbonate precipitation and soil alkalinity. Multiple regression analysis of the scores of the factors was performed to derive a fluoride contamination index in soil. The magnitude of the factor effect on the contamination index follows the order of Factor-1 > Factor-2 > Factor-3. The spatial distribution of the contamination index is used to classify the area into highly contaminated, moderately contaminated and uncontaminated zones.

  9. A New European Slope Length and Steepness Factor (LS-Factor for Modeling Soil Erosion by Water

    Directory of Open Access Journals (Sweden)

    Panos Panagos

    2015-04-01

    Full Text Available The Universal Soil Loss Equation (USLE model is the most frequently used model for soil erosion risk estimation. Among the six input layers, the combined slope length and slope angle (LS-factor has the greatest influence on soil loss at the European scale. The S-factor measures the effect of slope steepness, and the L-factor defines the impact of slope length. The combined LS-factor describes the effect of topography on soil erosion. The European Soil Data Centre (ESDAC developed a new pan-European high-resolution soil erosion assessment to achieve a better understanding of the spatial and temporal patterns of soil erosion in Europe. The LS-calculation was performed using the original equation proposed by Desmet and Govers (1996 and implemented using the System for Automated Geoscientific Analyses (SAGA, which incorporates a multiple flow algorithm and contributes to a precise estimation of flow accumulation. The LS-factor dataset was calculated using a high-resolution (25 m Digital Elevation Model (DEM for the whole European Union, resulting in an improved delineation of areas at risk of soil erosion as compared to lower-resolution datasets. This combined approach of using GIS software tools with high-resolution DEMs has been successfully applied in regional assessments in the past, and is now being applied for first time at the European scale.

  10. Oxygen diffusion in soils: Understanding the factors and processes needed for modeling

    Directory of Open Access Journals (Sweden)

    José Neira

    2015-08-01

    Full Text Available Oxygen is an important element for plant growth. Reducing its concentration in the soil affects plant physiological processes such as nutrient and water uptake as well as respiration, the redox potential of soil elements and the activity of microorganisms. The main mechanism of oxygen transport in the soil is by diffusion, a dynamic process greatly influenced by soil physical properties such as texture and structure, conditioning, pore size distribution, tortuosity and connectivity. Organic matter is a modifying agent of the soil's chemical and physical properties, affecting its structure and the porous matrix, which are determinants of oxygen transport. This study reviews the theory of soil gas diffusion and the effect of soil organic matter on the soil's physical properties and transport of gases. It also reviews gas diffusion models, particularly those including the effect of soil organic matter.

  11. Fever in trauma patients: evaluation of risk factors, including traumatic brain injury.

    Science.gov (United States)

    Bengualid, Victoria; Talari, Goutham; Rubin, David; Albaeni, Aiham; Ciubotaru, Ronald L; Berger, Judith

    2015-03-01

    The role of fever in trauma patients remains unclear. Fever occurs as a response to release of cytokines and prostaglandins by white blood cells. Many factors, including trauma, can trigger release of these factors. To determine whether (1) fever in the first 48 hours is related to a favorable outcome in trauma patients and (2) fever is more common in patients with head trauma. Retrospective study of trauma patients admitted to the intensive care unit for at least 2 days. Data were analyzed by using multivariate analysis. Of 162 patients studied, 40% had fever during the first 48 hours. Febrile patients had higher mortality rates than did afebrile patients. When adjusted for severity of injuries, fever did not correlate with mortality. Neither the incidence of fever in the first 48 hours after admission to the intensive care unit nor the number of days febrile in the unit differed between patients with and patients without head trauma (traumatic brain injury). About 70% of febrile patients did not have a source found for their fever. Febrile patients without an identified source of infection had lower peak white blood cell counts, lower maximum body temperature, and higher minimum platelet counts than did febrile patients who had an infectious source identified. The most common infection was pneumonia. No relationship was found between the presence of fever during the first 48 hours and mortality. Patients with traumatic brain injury did not have a higher incidence of fever than did patients without traumatic brain injury. About 30% of febrile patients had an identifiable source of infection. Further studies are needed to understand the origin and role of fever in trauma patients. ©2015 American Association of Critical-Care Nurses.

  12. A decision support system prototype including human factors based on the TOGA meta-theory approach

    International Nuclear Information System (INIS)

    Cappelli, M.; Memmi, F.; Gadomski, A. M.; Sepielli, M.

    2012-01-01

    The human contribution to the risk of operation of complex technological systems is often not negligible and sometimes tends to become significant, as shown by many reports on incidents and accidents occurred in the past inside Nuclear Power Plants (NPPs). An error of a human operator of a NPP can derive by both omission and commission. For instance, complex commission errors can also lead to significant catastrophic technological accidents, as for the case of the Three Mile Island accident. Typically, the problem is analyzed by focusing on the single event chain that has provoked the incident or accident. What is needed is a general framework able to include as many parameters as possible, i.e. both technological and human factors. Such a general model could allow to envisage an omission or commission error before it can happen or, alternatively, suggest preferred actions to do in order to take countermeasures to neutralize the effect of the error before it becomes critical. In this paper, a preliminary Decision Support System (DSS) based on the so-called (-) TOGA meta-theory approach is presented. The application of such a theory to the management of nuclear power plants has been presented in the previous ICAPP 2011. Here, a human factor simulator prototype is proposed in order to include the effect of human errors in the decision path. The DSS has been developed using a TRIGA research reactor as reference plant, and implemented using the LabVIEW programming environment and the Finite State Machine (FSM) model The proposed DSS shows how to apply the Universal Reasoning Paradigm (URP) and the Universal Management Paradigm (UMP) to a real plant context. The DSS receives inputs from instrumentation data and gives as output a suggested decision. It is obtained as the result of an internal elaborating process based on a performance function. The latter, describes the degree of satisfaction and efficiency, which are dependent on the level of responsibility related to

  13. Regulation of hippocampal neurogenesis by systemic factors including stress, glucocorticoids, sleep, and inflammation

    NARCIS (Netherlands)

    Lucassen, P.J.; Oomen, C.; van Dam, A.-M.; Czéh, B.; Gage, F.H.; Kempermann, G.; Song, H.

    2008-01-01

    This review summarizes and discusses the regulation of adult neurogenesis and hippocampal cellular plasticity by systemic factors. We focus on the role of stress, glucocorticoids, and related factors such as sleep deprivation and inflammation.

  14. Comparison of the Soil Dynamic Amplification Factor and Soil Amplification by Using Microtremor and MASW Methods Respectively

    Science.gov (United States)

    Tuncel, Aykut; Cevdet Özdag, Özkan; Pamuk, Eren; Akgün, Mustafa

    2017-12-01

    Single Station Microtremor method, which is widely used nowadays, is an effective and easy applicable method. In this study, dynamic amplification factor distributions of the study area were obtained using scenario earthquake parameters with single station microtremor data gathered at 112 points. In addition, a surface wave active method, which is known as MASW (Multichannel Analysis of Surface Waves), was applied at 43 profiles to calculate the soil amplification values. Dynamic amplification factor (DAF), soil amplification, the predominant soil period (PSP), geology and topography data of the study area were analysed together. Dynamic amplification factor and soil amplification values were obtained 2 or higher at about sea level parts of the study area which are generally composed of alluvial units. Additionally, in high altitude regions that are composed of volcanic rocks, relatively lower dynamic amplification factor and soil amplification values were obtained. The minimum amplification value in the study area was 1.15, while the maximum amplification value was 3.05 according to the dynamic amplification results and the soil amplification values were between 1.16 and 3.85 in harmony. It is seen that the obtained DAF values and the soil amplification values calculated from the seismic velocities are very similar to each other numerically and regionally. Because of this, it is concluded that the values of the soil amplification obtained by the MASW method and the calculated DAF values in this study are in harmony with each other. Although the depths of research in these two calculation methods are different from each other, the similarity of the results allows us to arrive at the result of how effective the ground layer is on the amplification. It has a great importance to calculate the amplification values and other dynamic parameters by in situ measurements for a planned plot because geological units can vary even at very short distances in heterogeneously

  15. Health Promotion Behavior of Chinese International Students in Korea Including Acculturation Factors: A Structural Equation Model.

    Science.gov (United States)

    Kim, Sun Jung; Yoo, Il Young

    2016-03-01

    The purpose of this study was to explain the health promotion behavior of Chinese international students in Korea using a structural equation model including acculturation factors. A survey using self-administered questionnaires was employed. Data were collected from 272 Chinese students who have resided in Korea for longer than 6 months. The data were analyzed using structural equation modeling. The p value of final model is .31. The fitness parameters of the final model such as goodness of fit index, adjusted goodness of fit index, normed fit index, non-normed fit index, and comparative fit index were more than .95. Root mean square of residual and root mean square error of approximation also met the criteria. Self-esteem, perceived health status, acculturative stress and acculturation level had direct effects on health promotion behavior of the participants and the model explained 30.0% of variance. The Chinese students in Korea with higher self-esteem, perceived health status, acculturation level, and lower acculturative stress reported higher health promotion behavior. The findings can be applied to develop health promotion strategies for this population. Copyright © 2016. Published by Elsevier B.V.

  16. Pipe elbow stiffness coefficients including shear and bend flexibility factors for use in direct stiffness codes

    International Nuclear Information System (INIS)

    Perry, R.F.

    1977-01-01

    Historically, developments of computer codes used for piping analysis were based upon the flexibility method of structural analysis. Because of the specialized techniques employed in this method, the codes handled systems composed of only piping elements. Over the past ten years, the direct stiffness method has gained great popularity because of its systematic solution procedure regardless of the type of structural elements composing the system. A great advantage is realized with a direct stiffness code that combines piping elements along with other structural elements such as beams, plates, and shells, in a single model. One common problem, however, has been the lack of an accurate pipe elbow element that would adequately represent the effects of transverse shear and bend flexibility factors. The purpose of the present paper is to present a systematic derivation of the required 12x12 stiffness matrix and load vectors for a three dimensional pipe elbow element which includes the effects of transverse shear and pipe bend flexibility according to the ASME Boiler and Pressure Vessel Code, Section III. The results are presented analytically and as FORTRAN subroutines to be directly incorporated into existing direct stiffness codes. (Auth.)

  17. Pesticide exposure as risk factor for non-Hodgkin lymphoma including histopathological subgroup analysis.

    Science.gov (United States)

    Eriksson, Mikael; Hardell, Lennart; Carlberg, Michael; Akerman, Måns

    2008-10-01

    We report a population based case-control study of exposure to pesticides as risk factor for non-Hodgkin lymphoma (NHL). Male and female subjects aged 18-74 years living in Sweden were included during December 1, 1999, to April 30, 2002. Controls were selected from the national population registry. Exposure to different agents was assessed by questionnaire. In total 910 (91 %) cases and 1016 (92%) controls participated. Exposure to herbicides gave odds ratio (OR) 1.72, 95% confidence interval (CI) 1.18-2.51. Regarding phenoxyacetic acids highest risk was calculated for MCPA; OR 2.81, 95% CI 1.27-6.22, all these cases had a latency period >10 years. Exposure to glyphosate gave OR 2.02, 95% CI 1.10-3.71 and with >10 years latency period OR 2.26, 95% CI 1.16-4.40. Insecticides overall gave OR 1.28, 95% CI 0.96-1.72 and impregnating agents OR 1.57, 95% CI 1.07-2.30. Results are also presented for different entities of NHL. In conclusion our study confirmed an association between exposure to phenoxyacetic acids and NHL and the association with glyphosate was considerably strengthened.

  18. Verrucomicrobial community structure and abundance as indicators for changes in chemical factors linked to soil fertility.

    Science.gov (United States)

    Navarrete, Acacio Aparecido; Soares, Tielle; Rossetto, Raffaella; van Veen, Johannes Antonie; Tsai, Siu Mui; Kuramae, Eiko Eurya

    2015-09-01

    Here we show that verrucomicrobial community structure and abundance are extremely sensitive to changes in chemical factors linked to soil fertility. Terminal restriction fragment length polymorphism fingerprint and real-time quantitative PCR assay were used to analyze changes in verrucomicrobial communities associated with contrasting soil nutrient conditions in tropical regions. In case study Model I ("Slash-and-burn deforestation") the verrucomicrobial community structures revealed disparate patterns in nutrient-enriched soils after slash-and-burn deforestation and natural nutrient-poor soils under an adjacent primary forest in the Amazonia (R = 0.819, P = 0.002). The relative proportion of Verrucomicrobia declined in response to increased soil fertility after slash-and-burn deforestation, accounting on average, for 4 and 2 % of the total bacterial signal, in natural nutrient-poor forest soils and nutrient-enriched deforested soils, respectively. In case study Model II ("Management practices for sugarcane") disparate patterns were revealed in sugarcane rhizosphere sampled on optimal and deficient soil fertility for sugarcane (R = 0.786, P = 0.002). Verrucomicrobial community abundance in sugarcane rhizosphere was negatively correlated with soil fertility, accounting for 2 and 5 % of the total bacterial signal, under optimal and deficient soil fertility conditions for sugarcane, respectively. In nutrient-enriched soils, verrucomicrobial community structures were related to soil factors linked to soil fertility, such as total nitrogen, phosphorus, potassium and sum of bases, i.e., the sum of calcium, magnesium and potassium contents. We conclude that community structure and abundance represent important ecological aspects in soil verrucomicrobial communities for tracking the changes in chemical factors linked to soil fertility under tropical environmental conditions.

  19. Sensitivity Analysis of the USLE Soil Erodibility Factor to Its Determining Parameters

    Science.gov (United States)

    Mitova, Milena; Rousseva, Svetla

    2014-05-01

    Soil erosion is recognized as one of the most serious soil threats worldwide. Soil erosion prediction is the first step in soil conservation planning. The Universal Soil Loss Equation (USLE) is one of the most widely used models for soil erosion predictions. One of the five USLE predictors is the soil erodibility factor (K-factor), which evaluates the impact of soil characteristics on soil erosion rates. Soil erodibility nomograph defines K-factor depending on soil characteristics, such as: particle size distribution (fractions finer that 0.002 mm and from 0.1 to 0.002 mm), organic matter content, soil structure and soil profile water permeability. Identifying the soil characteristics, which mostly influence the K-factor would give an opportunity to control the soil loss through erosion by controlling the parameters, which reduce the K-factor value. The aim of the report is to present the results of analysis of the relative weight of these soil characteristics in the K-factor values. The relative impact of the soil characteristics on K-factor was studied through a series of statistical analyses of data from the geographic database for soil erosion risk assessments in Bulgaria. Degree of correlation between K-factor values and the parameters that determine it was studied by correlation analysis. The sensitivity of the K-factor was determined by studying the variance of each parameter within the range between minimum and maximum possible values considering average value of the other factors. Normalizing transformation of data sets was applied because of the different dimensions and the orders of variation of the values of the various parameters. The results show that the content of particles finer than 0.002 mm has the most significant relative impact on the soil erodibility, followed by the content of particles with size from 0.1 mm to 0.002 mm, the class of the water permeability of the soil profile, the content of organic matter and the aggregation class. The

  20. Effects of silver nanoparticles (NM-300K) on Lumbricus rubellus earthworms and particle characterization in relevant test matrices including soil

    NARCIS (Netherlands)

    Ploeg, M.J.C. van der; Handy, R.D.; Waalewijn-Kool, P.L.; Berg, J.H.J. van den; Herrera Rivera, Z.E.; Bovenschen, J.; Molleman, B.; Baveco, J.M.; Tromp, P.; Peters, R.J.B.; Koopmans, G.F.; Rietjens, I.M.C.M.; Brink, N.W. van den

    2014-01-01

    The impact of silver nanoparticles (AgNP; at 0mg Ag/kg, 1.5mg Ag/kg, 15.4mg Ag/kg, and 154mg Ag/kg soil) and silver nitrate (AgNO3; 15.4mg Ag/kg soil) on earthworms, Lumbricus rubellus, was assessed. A 4-wk exposure to the highest AgNP treatment reduced growth and reproduction compared with the

  1. Insights into tetrabromobisphenol A adsorption onto soils: Effects of soil components and environmental factors.

    Science.gov (United States)

    Tong, Fei; Gu, Xueyuan; Gu, Cheng; Ji, Rong; Tan, Yinyue; Xie, Jinyu

    2015-12-01

    Concerns regarding tetrabromobisphenol A (TBBPA), the most widely utilized brominated flame retardant in the world, are growing because of the wide application and endocrine-disrupting potential of this compound. To properly assess its environmental impacts, it is important to understand the mobility and fate of TBBPA in soil environments. In this study, the effects of soil components, dissolved organic carbon (DOC) and heavy metal cations on TBBPA adsorption onto two Chinese soils (red soil and black soil) were investigated using batch sorption experiments. The desorption behavior of TBBPA when the two soils are irrigated with eutrophicated river water was also investigated. The results showed that pH greatly affects the adsorptive behavior of TBBPA in soils. Iron oxide minerals and phyllosilicate minerals are both active surfaces for TBBPA sorption, in addition to soil organic matter (SOM). DOC (50 mg OC L(-1)) exhibited a limited effect on TBBPA sorption only under neutral conditions. TBBPA sorption was only minimally affected by the heavy metals (Cu2+, Pb2+ and Cd2+) in the studied pH range. Eutrophicated river water significantly enhanced the desorption of TBBPA from red soil due to the change in soil solution pH. These findings indicate that mobility of TBBPA in soils is mainly associated with soil pH, organic matter and clay fractions: it will be retained by soils or sediments with high organic matter and clay fractions under acidic conditions but becomes mobile under alkaline conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Ressac program plants analytical experiments study of a code modelling the soil to plant transfer factor of cesium

    International Nuclear Information System (INIS)

    Jouve, A.; Troesch, O.; Legrand, B.

    1989-10-01

    The available data about the soil to plant transfer factor of cesium are numerous but very variable. The variation conditions of the transfer factor are studied with the help of laboratory experiments and the results analysed with the help of a multiple linear regression calculation. The results are applied to the soils and plants types the most frequently present around the French nuclear sites. A calculation model including the plant life conditions such as pH, water-soluble potassium and the available part of cesium in the water of the soil, is proposed. This model allows to predict the transfer factor with a better accuracy (up to ten times) than using the single ratio issue from the experimental data [fr

  3. Mars on Earth: Analog basaltic soils and particulates from Lonar Crater, India, include Deccan soil, shocked soil, reworked lithic and glassy ejecta, and both shocked and unshocked baked zones

    Science.gov (United States)

    Wright, S. P.

    2017-12-01

    "There is no perfect analog for Mars on Earth" [first line of Hipkin et al. (2013) Icarus, 261-267]. However, fieldwork and corresponding sample analyses from laboratory instrumentation (to proxy field instruments) has resulted in the finding of unique analog materials that suggest that detailed investigations of Lonar Crater, India would be beneficial to the goals of the Mars Program. These are briefly described below as Analog Processes, Materials, and Fieldwork. Analog Processes: The geologic history of Lonar Crater emulates localities on Mars with 1.) flood basaltic volcanism with interlayer development of 2.) baked zones or "boles" and 3.) soil formation. Of six flows, the lower three are aqueously altered by groundwater to produce a range of 4.) alteration products described below. The impact event 570 ka produced a range of 5.) impactites including shocked baked zones, shocked soils, and altered basalt shocked to a range of shock pressures [Kieffer et al., 1976]. Analog Materials: 65 Ma Deccan basalt contains augite and labradorite. Baked zones are higher in hematite and other iron oxides. Soil consists of calcite and organic matter. Several basalts with secondary alteration are listed here and these mirror alteration on Mars: hematite, chlorite, serpentine, zeolite, and palagonite, with varying combinations of these with primary igneous minerals. All of these materials (#1 through 4 above) are shocked to a range of shocked pressures to produce maskelynite, flowing plagioclase glass, vesiculated plagioclase glass, and complete impact melts. Shocked soils contain schlieren calcite amidst comminuted grains of augite, labradorite, and these glasses. Shocked baked zones unsurprisingly have a petrographic texture similar to hornfels, another product of contact metamorphism. Analog Fieldwork: The ejecta consists of two layers: 8 m of lithic breccia with unshocked and fractured basalts under a 1 m suevite consisting of all ranges of shock pressure described above

  4. Investigation of features in radon soil dynamics and search for influencing factors

    Science.gov (United States)

    Yakovlev, Grigorii; Cherepnev, Maxim; Nagorskiy, Petr; Yakovleva, Valentina

    2018-03-01

    The features in radon soil dynamics at two depths were investigated and the main influencing factors were revealed. The monitoring of radon volumetric activity in soil air was performed at experimental site of Tomsk Observatory of Radioactivity and Ionizing Radiation with using radon radiometers and scintillation detectors of alpha-radiation with 10 min sampling frequency. The detectors were installed into boreholes of 0.5 and 1 m depths. The analysis of the soil radon monitoring data has allowed revealing some dependencies at daily and annual scales and main influencing factors. In periods with clearly defined daily radon variations in the soil were revealed the next: 1) amplitude of the daily variations of the soil radon volumetric activity damps with the depth, that is related with the influence of convective fluxes in the soil; 2) temporal shift between times of occurrence of radon volumetric activity maximum (or minimum) values at 0.5 m and 1 m depths can reach 3 hours. In seasonal dynamics of the soil radon the following dependences were found: 1) maximal values are observed in winter, but minimal - in summer; 2) spring periods of snow melting are accompanied by anomaly increasing of radon volumetric activity in the soil up to about 3 times. The main influencing factors are atmospheric precipitations, temperature gradient in the soil and the state of upper soil layer.

  5. Soil transmitted Helminthiasis and associated risk factors among elementary school children in ambo town, western Ethiopia

    Directory of Open Access Journals (Sweden)

    Fikreslasie Samuel

    2017-10-01

    Full Text Available Abstract Background Soil-transmitted helminths (STHs are widespread in underdeveloped countries. In Ethiopia, the prevalence and distribution of helminth infection varies by different exposing risk factors. We therefore investigated the prevalence of and risk factors of STHs infection in school children living in Ambo town, west Shoa Ethiopia. Methods In 2014/15, among 375 school children planed to be included in this study, only 321 school children were recruited in the study. Data onto school children from different schools were collected, including stool samples for qualitative STHs analysis. Questionnaire data on various demographic, housing and lifestyle variables were also available. Results Prevalence of any STHs infection was 12.6%. The respective prevalence of major soil-transmitted helminths is Ascaris (7.8%, Hookworm (2.8% and Trichuris (2.2%. This study result shows STHs prevalence varies regards to age, sex, latrine use, family size and nail trimming. Conclusion The results of the present study indicated that the percentage of positive finding for STHs in Ambo area is low. Besides, Large Family size, not nail trimming and unavailability of improved latrine were identified as predisposing factor for STHs infections. All school children enrolled and not enrolled in this study should be treated twice a year until the prevalence falls below the level of public health importance.

  6. Soil transmitted Helminthiasis and associated risk factors among elementary school children in ambo town, western Ethiopia.

    Science.gov (United States)

    Samuel, Fikreslasie; Demsew, Asalif; Alem, Yonas; Hailesilassie, Yonas

    2017-10-10

    Soil-transmitted helminths (STHs) are widespread in underdeveloped countries. In Ethiopia, the prevalence and distribution of helminth infection varies by different exposing risk factors. We therefore investigated the prevalence of and risk factors of STHs infection in school children living in Ambo town, west Shoa Ethiopia. In 2014/15, among 375 school children planed to be included in this study, only 321 school children were recruited in the study. Data onto school children from different schools were collected, including stool samples for qualitative STHs analysis. Questionnaire data on various demographic, housing and lifestyle variables were also available. Prevalence of any STHs infection was 12.6%. The respective prevalence of major soil-transmitted helminths is Ascaris (7.8%), Hookworm (2.8%) and Trichuris (2.2%). This study result shows STHs prevalence varies regards to age, sex, latrine use, family size and nail trimming. The results of the present study indicated that the percentage of positive finding for STHs in Ambo area is low. Besides, Large Family size, not nail trimming and unavailability of improved latrine were identified as predisposing factor for STHs infections. All school children enrolled and not enrolled in this study should be treated twice a year until the prevalence falls below the level of public health importance.

  7. Factors controlling accumulation of soil organic carbon along vegetation succession in a typical karst region in Southwest China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shujuan [Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China); Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi Zhuang Autonomous Region 547100 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Wei [Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China); Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi Zhuang Autonomous Region 547100 (China); Wang, Kelin, E-mail: kelin@isa.ac.cn [Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China); Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi Zhuang Autonomous Region 547100 (China); Pan, Fujing [Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China); Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi Zhuang Autonomous Region 547100 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Yang, Shan [Changsha university, Changsha 410003 (China); Shu, Shiyan [Changjiang Project Supervision & Consultancy Co. Ltd, Wuhan 430010 (China); Changjiang Ecology (Hubei) Technology Development LLC, Wuhan 430010 (China)

    2015-07-15

    Vegetation succession enhances the accumulation of carbon in the soil. However, little is known about the mechanisms underlying soil organic carbon (SOC) accumulation in different vegetation types in the karst region of Southwest China. The goal of this study was to identify and prioritize the effects of environmental parameters, including soil physico-chemical properties, microbial biomass, enzyme activities, and litter characteristics, on SOC accumulation along a vegetation succession sere (grassland, shrubland, secondary forest, and primary forest) in the karst landscape of Southwest China. Relationships between these parameters and SOC were evaluated by redundancy analysis. The results showed that SOC accumulation was significantly different among vegetation types (P < 0.01) and increased with vegetation succession (from 29.10 g·kg{sup −1} in grassland to 73.92 g·kg{sup −1} in primary forest). Soil biochemistry and physical characteristics significantly affected the accumulation of SOC. Soil microbial biomass showed a predominant effect on SOC in each of the four vegetation types. In addition, the soil physical property (especially the silt content) was another controlling factor in the early stages (grassland), and urease activity and saccharase activity were important controlling factors in the early-middle and middle-late stages, respectively. Litter characteristics only showed mild effects on SOC accumulation. Variation partitioning analysis showed that the contribution of sole main factors to SOC variation decreased, while the interaction effect among parameters increased along the succession gradient. - Highlights: • Vegetation restoration is conducive to soil carbon sequestration in karst areas. • The factors controlling SOC accumulation differed along vegetation succession. • The interaction effect among significant factors became more and more prominent along succession.

  8. The Value Range of Contact Stiffness Factor between Pile and Soil Based on Penalty Function

    Science.gov (United States)

    Chen, Sandy H. L.; Wu, Xinliu

    2018-03-01

    The value range of contact stiffness factor based on penalty function is studied when we use finite element software ANSYS to analyze contact problems, take single pile and soil of a certain project for example, the normal contact between pile and soil is analyzed with 2D simplified model in horizontal load. The study shows that when adopting linear elastic model to simulate soil, the maximum contact pressure and penetration approach steady value as the contact stiffness factor increases. The reasonable value range of contact stiffness factor reduces as the underlying element thickness decreases, but the rule reverses when refers to the soil stiffness. If choose DP model to simulate soil, the stiffness factor should be magnified 100 times compares to the elastic model regardless of the soil bears small force and still in elastic deformation stage or into the plastic deformation stage. When the soil bears big force and into plastic deformation stage, the value range of stiffness factor relates to the plastic strain range of the soil, and reduces as the horizontal load increases.

  9. Morphological and molecular characterization of selected desert soil cyanobacteria: Three species new to science including .i.Mojavia pulchra./i. gen. et sp. nov

    Czech Academy of Sciences Publication Activity Database

    Řeháková, Klára; Johansen, J. R.; Casamatta, D.A.; Xuesong, L.; Vincent, J.

    2007-01-01

    Roč. 46, č. 5 (2007), s. 481-502 ISSN 0031-8884 R&D Projects: GA ČR(CZ) GP206/03/P024 Institutional research plan: CEZ:AV0Z60170517 Keywords : Mojavia * microbiotic soil crusts * Nostoc Subject RIV: EF - Botanics Impact factor: 1.358, year: 2007

  10. Preliminary identification of the bioremediation limiting factors of a clay bearing soil contaminated with crude oil

    OpenAIRE

    Rizzo, Andréa C. L.; Cunha, Claudia D. da; Santos, Ronaldo L. C.; Santos, Renata M.; Magalhães, Hugo M.; Leite, Selma G. F.; Soriano, Adriana U.

    2008-01-01

    Bioremediation is an attractive alternative to treat soils contaminated with petroleum hydrocarbons. However, the effectiveness of biodegradation process can be limited by both contaminant characteristics and its bioavailability in soil. This work aims at establishing a preliminary procedure to identify the main factor (hydrocarbon recalcitrance or its bioavailability) that impairs the biodegradation, possibly resulting in low remediation efficiencies. Tests in soil microcosms were carried ou...

  11. Biological soil crust effects must be included to accurately model infiltration and erosion in drylands : an example from Tabernas Badlands

    NARCIS (Netherlands)

    Rodriguez-Caballero, E.; Canton, Y.; Jetten, V.G.

    2015-01-01

    In dryland ecosystems, runoff is mainly generated in bare areas, which are also more susceptible to water erosion than vegetated areas. These bare areas are often covered and protected by biological soil crusts (BSCs), which modify numerous physicochemical surface properties involved in runoff and

  12. Bioaugmentation of soil contaminated with high-level crude oil through inoculation with mixed cultures including Acremonium sp.

    Science.gov (United States)

    Ma, Xiao-Kui; Ding, Ning; Peterson, Eric Charles

    2015-06-01

    Heavy contamination of soil with crude oil has caused significant negative environmental impacts and presents substantial hazards to human health. To explore a highly efficient bioaugmentation strategy for these contaminations, experiments were conducted over 180 days in soil heavily contaminated with crude oil (50,000 mg kg(-1)), with four treatments comprised of Bacillus subtilis inoculation with no further inoculation (I), or reinoculation after 100 days with either B. subtilis (II), Acremonium sp.(III), or a mixture of both organisms (IV). The removal values of total petroleum hydrocarbons were 60.1 ± 2.0, 60.05 ± 3.0, 71.3 ± 5.2 and 74.2 ± 2.7 % for treatment (I-IV), respectively. Treatments (III-IV) significantly enhanced the soil bioremediation compared with treatments (I-II) (p oil heavy fractions. Dehydrogenase activity in treatment (III-IV) containing Acremonium sp. showed a constant increase until the end of experiments. Therefore reinoculation with pure fungus or fungal-bacterial consortium should be considered as an effective strategy in bioaugmentation for soil heavily contaminated with crude oil.

  13. Improving ecological risk assessment by including bioavailability into species sensitivity distributions: An example for plants exposed to nickel in soil

    International Nuclear Information System (INIS)

    Semenzin, Elena; Temminghoff, Erwin J.M.; Marcomini, Antonio

    2007-01-01

    The variability of species sensitivity distribution (SSD) due to contaminant bioavailability in soil was explored by using nickel as metal of concern. SSDs of toxicity test results of Avena sativa L. originating from different soils and expressed as total content and available (0.01 M CaCl 2 ) extractable concentration were compared to SSDs for terrestrial plants derived from literature toxicity data. Also the 'free' nickel (Ni 2+ ) concentration was calculated and compared. The results demonstrated that SSDs based on total nickel content highly depend on the experimental conditions set up for toxicity testing (i.e. selected soil and pH value) and thus on metal bioavailability in soil, resulting in an unacceptable uncertainty for ecological risk estimation. The use in SSDs of plant toxicity data expressed as 0.01 M CaCl 2 extractable metal strongly reduced the uncertainty in the SSD curve and thus can improve the ERA procedure remarkably by taking bioavailability into account. - The use of bioavailability toxicity data can improve species sensitivity distribution (SSD) curves and thus ecological risk assessment (ERA)

  14. Risk Factor Analysis for AKI Including Laboratory Indicators: a Nationwide Multicenter Study of Hospitalized Patients

    Directory of Open Access Journals (Sweden)

    Sasa Nie

    2017-10-01

    Full Text Available Background/Aims: Risk factor studies for acute kidney injury (AKI in China are lacking, especially those regarding non-traditional risk factors, such as laboratory indicators. Methods: All adult patients admitted to 38 tertiary and 22 secondary hospitals in China in any one month between July and December 2014 were surveyed. AKI patients were screened according to the Kidney Disease: Improving Global Outcomes’ definition of AKI. Logistic regression was used to analyze the risk factors for AKI, and Cox regression was used to analyze the risk of in-hospital mortality for AKI patients; additionally, a propensity score analysis was used to reconfirm the risk factors among laboratory indicators for mortality. Results: The morbidity of AKI was 0.97%. Independent risk factors for AKI were advancing age, male gender, hypertension, and chronic kidney disease. All-cause mortality was 16.5%. The predictors of mortality in AKI patients were advancing age, tumor, higher uric acid level and increases in Acute Physiologic Assessment and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores. The hazard ratio (HR for mortality with uric acid levels > 9.1 mg/dl compared with ≤ 5.2 mg/dl was 1.78 (95% CI: 1.23 to 2.58 for the AKI patients as a group, and was 1.73 (95% CI: 1.24 to 2.42 for a propensity score-matched set. Conclusion: In addition to traditional risk factors, uric acid level is an independent predictor of all-cause mortality after AKI.

  15. Influence of environmental factors on the spatial distribution and diversity of forest soil in Latvia

    Directory of Open Access Journals (Sweden)

    Raimonds Kasparinskis

    2012-02-01

    Full Text Available This study was carried out to determine the spatial relationships between environmental factors (Quaternary deposits, topographical situation, land cover, forest site types, tree species, soil texture and soil groups, and their prefix qualifiers (according to the international Food and Agricultural Organization soil classification system World Reference Base for Soil Resources [FAO WRB]. The results show that it is possible to establish relationships between the distribution of environmental factors and soil groups by applying the generalized linear models in data statistical analysis, using the R 2.11.1 software for processing data from 113 sampling plots throughout the forest territory of Latvia.A very high diversity of soil groups in a relatively similar geological structure was revealed. For various reasons there is not always close relationship between the soil group, their prefix qualifiers and Quaternary deposits, as well as between forest site types, the dominant tree species and specific soil group and its prefix qualifiers. Close correlation was established between Quaternary deposits, forest site types, dominant tree species and soil groups within nutrient-poor sediments and very rich deposits containing free carbonates. No significant relationship was detected between the CORINE Land Cover 2005 classes, topographical situation and soil group.

  16. Major controlling factors and predictions for cadmium transfer from the soil into spinach plants.

    Science.gov (United States)

    Liang, Zhenfei; Ding, Qiong; Wei, Dongpu; Li, Jumei; Chen, Shibao; Ma, Yibing

    2013-07-01

    Predicting the mobility, bioavailability and transfer of cadmium (Cd) in the soil-plant system is of great importance with regards to food safety and environmental management. In this study, the transfer characteristics of Cd (exogenous salts) from a wide range of Chinese soils to spinach (Spinacia oleracea L.) were investigated. The major controlling factors and prediction equations for Cd transfer in the soil-plant system were also investigated. The results showed that plant Cd concentration was positively correlated with soil Cd concentration. The maximum transfer factor (ratio of the Cd concentration in the plant to that in the soil) was found in acid soils. The extended Freundlich-type function was able to describe the Cd transfer from soil to spinach plants. Combining soil total Cd, pH and organic carbon (OC) content in the prediction equation greatly improved the correlation performance compared with predictions based on total Cd only. A slight protection effect of OC on Cd uptake was observed at low soil Cd concentrations. The results are a useful tool that can be used to predict Cd transfer from soil to plant. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. [Effects of land use and environmental factors on the variability of soil quality indicators in hilly Loess Plateau region of China].

    Science.gov (United States)

    Xu, Ming-Xiang; Liu, Guo-Bin; Zhao, Yun-Ge

    2011-02-01

    Classical statistics methods were adopted to analyze the soil quality variability, its affecting factors, and affecting degree at a regional scale (700 km2) in the central part of hilly Loess Plateau region of China. There existed great differences in the variability of test soil quality indicators. Soil pH, structural coefficient, silt content, specific gravity, bulk density, total porosity, capillary porosity, and catalase activity were the indicators with weak variability; soil nutrients (N, P, and K) contents, CaCO3 content, cation exchange capacity (CEC), clay content, micro-aggregate mean mass diameter, aggregate mean mass diameter, water-stable aggregates, respiration rate, microbial quotient, invertase and phosphatase activities, respiratory quotient, and microbial carbon and nitrogen showed medium variation; while soil labile organic carbon and phosphorus contents, erosion-resistance, permeability coefficient, and urease activity were the indicators with strong variability. The variability of soil CaCO3, total P and K, CEC, texture, and specific gravity, etc. was correlated with topography and other environmental factors, while the variability of dynamic soil quality indicators, including soil organic matter content, nitrogen content, water-stable aggregates, permeability, microbial biomass carbon and nitrogen, enzyme activities, and respiration rate, was mainly correlated with land use type. Overall, land use pattern explained 97% of the variability of soil quality indicators in the region. It was suggested that in the evaluation of soil quality in hilly Loess Plateau region, land use type and environmental factors should be fully considered.

  18. A PEDOTRANSFER FUNCTION FOR ESTIMATING THE SOIL ERODIBILITY FACTOR IN SICILY

    Directory of Open Access Journals (Sweden)

    Vincenzo Bagarello

    2009-09-01

    Full Text Available The soil erodibility factor, K, of the Universal Soil Loss Equation (USLE is a simple descriptor of the soil susceptibility to rill and interrill erosion. The original procedure for determining K needs a knowledge of soil particle size distribution (PSD, soil organic matter, OM, content, and soil structure and permeability characteristics. However, OM data are often missing and soil structure and permeability are not easily evaluated in regional analyses. The objective of this investigation was to develop a pedotransfer function (PTF for estimating the K factor of the USLE in Sicily (south Italy using only soil textural data. The nomograph soil erodibility factor and its associated first approximation, K’, were determined at 471 sampling points distributed throughout the island of Sicily. Two existing relationships for estimating K on the basis of the measured geometric mean particle diameter were initially tested. Then, two alternative PTFs for estimating K’ and K, respectively, on the basis of the measured PSD were derived. Testing analysis showed that the K estimate by the proposed PTF (eq.11, which was characterized by a Nash-Suttcliffe efficiency index, NSEI, varying between 0.68 and 0.76, depending on the considered data set, was appreciably more accurate than the one obtained by other existing equations, yielding NSEI values varying between 0.21 and 0.32.

  19. Situational effects of the school factors included in the dynamic model of educational effectiveness

    NARCIS (Netherlands)

    Creerners, Bert; Kyriakides, Leonidas

    We present results of a longitudinal study in which 50 schools, 113 classes and 2,542 Cypriot primary students participated. We tested the validity of the dynamic model of educational effectiveness and especially its assumption that the impact of school factors depends on the current situation of

  20. Effect of the edaphic factors and metal content in soil on the diversity of Trichoderma spp.

    Science.gov (United States)

    Racić, Gordana; Körmöczi, Péter; Kredics, László; Raičević, Vera; Mutavdžić, Beba; Vrvić, Miroslav M; Panković, Dejana

    2017-02-01

    Influence of edaphic factors and metal content on diversity of Trichoderma species at 14 different soil sampling locations, on two depths, was examined. Forty-one Trichoderma isolates from 14 sampling sites were determined as nine species based on their internal transcribed spacer (ITS) sequences. Our results indicate that weakly alkaline soils are rich sources of Trichoderma strains. Also, higher contents of available K and P are connected with higher Trichoderma diversity. Increased metal content in soil was not inhibiting factor for Trichoderma species occurrence. Relationship between these factors was confirmed by locally weighted sequential smoothing (LOESS) nonparametric smoothing analysis. Trichoderma strain (Szeged Microbiology Collection (SZMC) 22669) from soil with concentrations of Cr and Ni above remediation values should be tested for its potential for bioremediation of these metals in polluted soils.

  1. Soil-plant-transfer factors for I-129 and pasture vegetation

    International Nuclear Information System (INIS)

    Haisch, A.; Schuettelkopf, H.

    1993-07-01

    The transfer factors for soil/plant, I-129 and I-127 and pasture vegetation have been measured with soils developed by wethering of granite, jura and cretaceous formations. Greenhouse (Karlsruhe) and field experiments (Munich) have been performed using lysimeters. Three ground water levels and the influence of a six weeks flooding was measured. About 90% of the transfer factors ranged from 0.000 to 0.020. The highest values have been determined with soils from granite wethering. The flooding of the lysimeters caused an important increase of the transfer factors after the end of flooding. (orig.) [de

  2. Modeling redistribution of α-HCH in Chinese soil induced by environment factors

    International Nuclear Information System (INIS)

    Tian, Chongguo; Liu Liyan; Ma Jianmin; Tang Jianhui; Li Yifan

    2011-01-01

    This study explores long-term environmental fate of α-HCH in China from 1952 to 2007 using ChnGPERM (Chinese Gridded Pesticide Emission and Residue Model). The model captures well the temporal and spatial variations of α-HCH concentration in Chinese soils by comparing with a number of measured data across China in different periods. The results demonstrate α-HCH grasshopping effect in Eastern China and reveal several important features of the chemical in Northeast and Southeast China. It is found that Northeast China is a prominent sink region of α-HCH emitted from Chinese sources and α-HCH contamination in Southwest China is largely attributed to foreign sources. Southeast China is shown to be a major source contributing to α-HCH contamination in Northeast China, incurred by several environmental factors including temperature, soil organic carbon content, wind field and precipitation. - Highlights: → Grasshopping effect is found in Eastern China. → Northeast China is a prominent sink region of α-HCH emitted from Chinese sources. → Southeast China is a major source region to α-HCH contamination in Northeast China. → The source-sink relationship is incurred by several environmental factors. - This study provides the first comprehensive overview to redistribution of a toxic chemical incurred by long-term variation of environmental factors across China.

  3. Mapping Soil Erosion Factors and Potential Erosion Risk for the National Park "Central Balkan"

    Science.gov (United States)

    Ilieva, Diliana; Malinov, Ilia

    2014-05-01

    Soil erosion is widely recognised environmental problem. The report aims at presenting the main results from assessment and mapping of the factors of sheet water erosion and the potential erosion risk on the territory of National Park "Central Balkan". For this purpose, the Universal Soil Loss Equation (USLE) was used for predicting soil loss from erosion. The influence of topography (LS-factor) and soil erodibility (K-factor) was assessed using small-scale topographic and soil maps. Rainfall erosivity (R-factor) was calculated from data of rainfalls with amounts exceeding 9.5 mm from 14 hydro-meteorological stations. The values of the erosion factors (R, K and LS) were presented for the areas of forest, sub-alpine and alpine zones. Using the methods of GIS, maps were plotted presenting the area distribution among the classes of the soil erosion factors and the potential risk in the respective zones. The results can be used for making accurate decisions for soil conservation and sustainable land management in the park.

  4. Temporal changes of spatial soil moisture patterns: controlling factors explained with a multidisciplinary approach

    Science.gov (United States)

    Martini, Edoardo; Wollschläger, Ute; Kögler, Simon; Behrens, Thorsten; Dietrich, Peter; Reinstorf, Frido; Schmidt, Karsten; Weiler, Markus; Werban, Ulrike; Zacharias, Steffen

    2016-04-01

    Characterizing the spatial patterns of soil moisture is critical for hydrological and meteorological models, as soil moisture is a key variable that controls matter and energy fluxes and soil-vegetation-atmosphere exchange processes. Deriving detailed process understanding at the hillslope scale is not trivial, because of the temporal variability of local soil moisture dynamics. Nevertheless, it remains a challenge to provide adequate information on the temporal variability of soil moisture and its controlling factors. Recent advances in wireless sensor technology allow monitoring of soil moisture dynamics with high temporal resolution at varying scales. In addition, mobile geophysical methods such as electromagnetic induction (EMI) have been widely used for mapping soil water content at the field scale with high spatial resolution, as being related to soil apparent electrical conductivity (ECa). The objective of this study was to characterize the spatial and temporal pattern of soil moisture at the hillslope scale and to infer the controlling hydrological processes, integrating well established and innovative sensing techniques, as well as new statistical methods. We combined soil hydrological and pedological expertise with geophysical measurements and methods from digital soil mapping for designing a wireless soil moisture monitoring network. For a hillslope site within the Schäfertal catchment (Central Germany), soil water dynamics were observed during 14 months, and soil ECa was mapped on seven occasions whithin this period of time using an EM38-DD device. Using the Spearman rank correlation coefficient, we described the temporal persistence of a dry and a wet characteristic state of soil moisture as well as the switching mechanisms, inferring the local properties that control the observed spatial patterns and the hydrological processes driving the transitions. Based on this, we evaluated the use of EMI for mapping the spatial pattern of soil moisture under

  5. Factors controlling the spatial distribution of soil piping erosion on loess-derived soils: A case study from central Belgium

    Science.gov (United States)

    Verachtert, E.; Van Den Eeckhaut, M.; Poesen, J.; Deckers, J.

    2010-06-01

    Collapsible loess-derived soils are prone to soil piping erosion, where enlargement of macropores may lead to a subsurface pipe network and eventually to soil collapse and gully development. This study aims at understanding the main factors controlling spatial patterns of piping in loess-derived soils under a temperate climate. To map the spatial distribution of piping and identify the environmental controls on its distribution, a regional survey was carried out in a 236 km 2 study area in the Flemish Ardennes (Belgium). Orthophotos taken at optimal field conditions (winter) were analyzed to detect piping in open landscapes and ground thruthing was systematically done through field surveys. In total, 137 parcels having 560 collapsed pipes were mapped. Dimensions of the sinkholes and local slope gradient were measured in the field and topographical variables were derived from LiDAR data. Land use plays an important role as 97% of the sites with piping are found under pasture. The probability of piping increases rapidly on hillslopes with gradients exceeding 8% and with a concave profile and plan curvature, enhancing subsurface flow concentration. The zones with soil profiles on shallow loess over a relatively thin layer of homogeneous blue massive clays (Aalbeke Member) are most prone to piping. Soil characteristics are of less importance to explain piping occurrence. Furthermore, the topographical threshold line indicating the critical slope gradient for a given contributing drainage area was determined. This threshold line (negative power relation) is similar to the threshold line for shallow gully initiation.

  6. Soil-plant transfer factors of Co-60 for alfalfa lettuce and spinach

    International Nuclear Information System (INIS)

    Dumitru, Radu Octavian

    1997-01-01

    The transfer of Co-60 from soil into plants is a less studied problem. Soil-plant transfer factors for Co-60 known from literature vary by about four orders of magnitude for each kind of plants. We have calculated the average values and have determined the field of variability of the known transfer factors. These indicated us that alfalfa, lettuce and spinach have in this order the greatest absorption capacity of Co-60 from soil. We have determined the physical, chemical and mineralogical properties of the utilized soil. This is a brown reddish forest type soil. The plants have been cultivated in pots by plantlet method of Neubauer and Schneider. The results of our measurements of soil-to-plant transfer factors of 60-Co are the followings: 0.0612 ± 0.0047 for alfalfa, 0.0960 ± 0.0072 for lettuce and 0.1446 ± 0.0107 for spinach. These values prove the strong dependence of the type of soil and plant of the soil-plant transfer factors for Co-60. (author)

  7. Factors influencing adoption of soil and water conservation measures in southern Mali

    NARCIS (Netherlands)

    Bodnar, F.; Graaff, de J.

    2003-01-01

    A soil and water conservation (SWC) extension programme, promoting erosion control measures and soil fertility measures, has been going on in southern Mali since 1986. Five factors that influence farmer adoption of SWC measures were analysed: land pressure, cotton-growing area, possession of

  8. The dyad palindromic glutathione transferase P enhancer binds multiple factors including AP1.

    Science.gov (United States)

    Diccianni, M B; Imagawa, M; Muramatsu, M

    1992-10-11

    Glutathione Transferase P (GST-P) gene expression is dominantly regulated by an upstream enhancer (GPEI) consisting of a dyad of palindromically oriented imperfect TPA (12-O-tetradecanoyl-phorbol-13-acetate)-responsive elements (TRE). GPEI is active in AP1-lacking F9 cells as well in AP1-containing HeLa cells. Despite GPEI's similarity to a TRE, c-jun co-transfection has only a minimal effect on transactivation. Antisense c-jun and c-fos co-transfection experiments further demonstrate the lack of a role for AP1 in GPEI mediated trans-activation in F9 cells, although endogenously present AP1 can influence GPEI in HeLa cells. Co-transfection of delta fosB with c-jun, which forms an inactive c-Jun/delta FosB heterodimer that binds TRE sequences, inhibits GPEI-mediated transcription in AP1-lacking F9 cells as well as AP1-containing HeLa cells. These data suggest novel factor(s) other than AP1 are influencing GPEI. Binding studies reveal multiple nucleoproteins bind to GPEI. These factors are likely responsible for the high level of GPEI-mediated transcription observed in the absence of AP1 and during hepatocarcinogenesis.

  9. Factors affecting the selection of a soil water sensing technology

    International Nuclear Information System (INIS)

    Hignett, C.T.

    2000-01-01

    Reviews of soil moisture measurement technologies are counterproductive in attempting to identify the single approach that has the best overall performance for a range of soil, crop and landscape conditions. Not only does such an approach preclude the addition of new technologies, but it also obscures the fact that we have available today sensors and technologies that cover most field conditions, are well understood in terms of technical capability and are mechanically and electronically reliable. This review defines decision-making processes for assessing the characteristics, good and bad, of technology in relation to project objectives. Two processes are needed. The first links soil texture and scale of variability with the nature of the project, single-plant to catchment scale, to the needs for soil water measurement. The second lists the capabilities of some devices and shows how they can be selected to accommodate necessary criteria. It is concluded that the 'best technology' is a function of the project and soil conditions. (author)

  10. Anthropic changes to the biotic factor of soil formation from forests to managed grasslands along summits of the western Pyrenees Mountains, France

    Science.gov (United States)

    Leigh, David; Gragson, Theodore

    2017-04-01

    Mounting evidence indicates that highland pastures of the humid-temperate western Pyrenees were converted from mixed forests to managed grasslands thousands of years ago, as early as during the late Neolithic and Bronze age by human actions including use of fire. We observe pronounced differences between soil profiles of ancient pastures and old-growth forests in otherwise similar landscape positions. In order to test physical and chemical differences, we collected paired samples of forest versus grassland soils at four separate hillslope sites where there was a clear boundary between the two vegetation types. Animal trails were excluded from sampling. Factors of climate, topography, parent material, and time of soil formation were essentially identical in the forests and pastures of each site, but the time of soil under grassland vegetation may have varied. Each paired hillslope site included five core samples (7.6 cm diameter) from the upper 7.6 cm of the mineral soil within each vegetation type, and the A horizon thickness was recorded at each core hole site. In addition, one complete soil profile was sampled in each vegetation type at each site, making a total of 20 core samples and 4 complete profiles from each respective vegetation type. In addition, we measured the magnetic susceptibility of the mineral soil surface on two transects crossing the vegetation boundary. Core samples have been measured for bulk density, pH, plant-available nutrients, and organic matter; and tests for total carbon and nitrogen, amorphous silica, charcoal, and other forms of black carbon are ongoing. Preliminary results indicate pastured A horizons are about three times as thick as forested soils, contain more organic matter, have lower soil bulk densities, have much finer and stronger structural development of soil aggregates. These traits favor much greater infiltration and water holding capacities of the pastured soils, which we have validated with saturated hydraulic

  11. Effects of soil and topographic factors on vegetation restoration in opencast coal mine dumps located in a loess area

    Science.gov (United States)

    Wang, Jinman; Wang, Hongdan; Cao, Yingui; Bai, Zhongke; Qin, Qian

    2016-02-01

    Vegetation plays an important role in improving and restoring fragile ecological environments. In the Antaibao opencast coal mine, located in a loess area, the eco-environment has been substantially disturbed by mining activities, and the relationship between the vegetation and environmental factors is not very clear. Therefore, it is crucial to understand the effects of soil and topographic factors on vegetation restoration to improve the fragile ecosystems of damaged land. An investigation of the soil, topography and vegetation in 50 reclamation sample plots in Shanxi Pingshuo Antaibao opencast coal mine dumps was performed. Statistical analyses in this study included one-way ANOVA and significance testing using SPSS 20.0, and multivariate techniques of detrended correspondence analysis (DCA) and redundancy analysis (RDA) using CANOCO 4.5. The RDA revealed the environmental factors that affected vegetation restoration. Various vegetation and soil variables were significantly correlated. The available K and rock content were good explanatory variables, and they were positively correlated with tree volume. The effects of the soil factors on vegetation restoration were higher than those of the topographic factors.

  12. Effects of soil and topographic factors on vegetation restoration in opencast coal mine dumps located in a loess area

    Science.gov (United States)

    Wang, Jinman; Wang, Hongdan; Cao, Yingui; Bai, Zhongke; Qin, Qian

    2016-01-01

    Vegetation plays an important role in improving and restoring fragile ecological environments. In the Antaibao opencast coal mine, located in a loess area, the eco-environment has been substantially disturbed by mining activities, and the relationship between the vegetation and environmental factors is not very clear. Therefore, it is crucial to understand the effects of soil and topographic factors on vegetation restoration to improve the fragile ecosystems of damaged land. An investigation of the soil, topography and vegetation in 50 reclamation sample plots in Shanxi Pingshuo Antaibao opencast coal mine dumps was performed. Statistical analyses in this study included one-way ANOVA and significance testing using SPSS 20.0, and multivariate techniques of detrended correspondence analysis (DCA) and redundancy analysis (RDA) using CANOCO 4.5. The RDA revealed the environmental factors that affected vegetation restoration. Various vegetation and soil variables were significantly correlated. The available K and rock content were good explanatory variables, and they were positively correlated with tree volume. The effects of the soil factors on vegetation restoration were higher than those of the topographic factors. PMID:26916152

  13. Effectiveness of Tuned Mass Dampers in Seismic Response Control of Isolated Bridges Including Soil-Structure Interaction

    Directory of Open Access Journals (Sweden)

    Said Elias

    Full Text Available Abstract The effect of soil-structure interaction (SSI on the dynamic responses of seismically isolated three-span continuous reinforced concrete (RC bridge is investigated. Also, tuned mass damper(s (TMD/s is/are installed to control undesirable bearing displacement, even under the SSI effect. The TMDs are placed at the mid-span of the bridge and each tuned with a modal frequency, while controlling up to first few modes as desirable. The soil surrounding the foundation of pier is modeled by frequency independent coefficients. Dynamic analysis is carried out in time domain using direct integration method. In order to specify the effects of the SSI, the responses of the non-isolated, isolated, and controlled isolated bridge are compared. It is observed that the soil surrounding the pier has significant effects on the bearing displacement of the isolated RC bridges. In addition, it is observed that the seismic responses of isolated RC bridge reduced significantly with installation of the TMDs.

  14. Variations in Carabidae assemblages across the farmland habitats in relation to selected environmental variables including soil properties

    Directory of Open Access Journals (Sweden)

    Beáta Baranová

    2018-03-01

    Full Text Available The variations in ground beetles (Coleoptera: Carabidae assemblages across the three types of farmland habitats, arable land, meadows and woody vegetation were studied in relation to vegetation cover structure, intensity of agrotechnical interventions and selected soil properties. Material was pitfall trapped in 2010 and 2011 on twelve sites of the agricultural landscape in the Prešov town and its near vicinity, Eastern Slovakia. A total of 14,763 ground beetle individuals were entrapped. Material collection resulted into 92 Carabidae species, with the following six species dominating: Poecilus cupreus, Pterostichus melanarius, Pseudoophonus rufipes, Brachinus crepitans, Anchomenus dorsalis and Poecilus versicolor. Studied habitats differed significantly in the number of entrapped individuals, activity abundance as well as representation of the carabids according to their habitat preferences and ability to fly. However, no significant distinction was observed in the diversity, evenness neither dominance. The most significant environmental variables affecting Carabidae assemblages species variability were soil moisture and herb layer 0-20 cm. Another best variables selected by the forward selection were intensity of agrotechnical interventions, humus content and shrub vegetation. The other from selected soil properties seem to have just secondary meaning for the adult carabids. Environmental variables have the strongest effect on the habitat specialists, whereas ground beetles without special requirements to the habitat quality seem to be affected by the studied environmental variables just little.

  15. Modelling of safety barriers including human and organisational factors to improve process safety

    DEFF Research Database (Denmark)

    Markert, Frank; Duijm, Nijs Jan; Thommesen, Jacob

    2013-01-01

    It is believed that traditional safety management needs to be improved on the aspect of preparedness for coping with expected and unexpected deviations, avoiding an overly optimistic reliance on safety systems. Remembering recent major accidents, such as the Deep Water Horizon, the Texas City....... A valuable approach is the inclusion of human and organisational factors into the simulation of the reliability of the technical system using event trees and fault trees and the concept of safety barriers. This has been demonstrated e.g. in the former European research project ARAMIS (Accidental Risk...

  16. SUBSTANTIATION OF THE COST OF HOUSING CONSTRUCTION INCLUDING THE FACTOR OF INVESTMENT ATTRACTIVENESS OF TERRITORIES

    Directory of Open Access Journals (Sweden)

    ZAIATS Yi. I.

    2015-11-01

    Full Text Available Problem statement. For planning and organization of urban construction is necessary to analyze the use of areas. Territorial resources of the city, being used for construction and other urban purposes, consists of plots of land: disposable, reserved and undeveloped in previous years of construction in progress; residential districts and blocks of obsolete housing fund; industrial and municipal and warehouse enterprises being used irrationally or stopped to work; the defence department, where the amortized warehouses and other main funds are that are not used by purpose; agricultural enterprises where the obsolete industrial funds, haying, nurseries, greenhouses. The number of free areas suitable for future urban development is extremely limited. However a considerable part of the territories of almost all functional zones is used inefficiently. Purpose. Formalization of a factor of investment attractiveness of territories for the further identification and research of the connection between it and the cost of housing construction is necessary. Conclusion. The identification of regularities of influence of the factor of investment attractiveness of territories on the cost of construction of high-rise buildings allow to obtain a quantitative estimate of this effect and can be used in the development of the methodology of substantiation of the expediency and effectiveness of the implementation of highrise construction projects, based on organizational and technological aspects.

  17. The influence of site factors on nitrogen mineralization in forest soils ...

    African Journals Online (AJOL)

    The influence of site factors on nitrogen mineralization in forest soils of the ... on N mineralization, as well as the effect of N mineralization on forest productivity. ... of the natural log of mean annual temperature, geological substrate and total N ...

  18. Influence of the soil sealing on the geoaccumulation index of heavy metals and various pollution factors.

    Science.gov (United States)

    Charzyński, Przemysław; Plak, Andrzej; Hanaka, Agnieszka

    2017-02-01

    Soil sealing belongs to the most destructive and damaging processes to the soil environment. Soil sealing interrupts or greatly restricts the exchange of matter and energy between the biosphere, hydrosphere, and atmosphere and the soil environment. The aim of this study was to compare the content of heavy metals (Cd, Cr, Cu, Hg, Fe, Ni, Pb, Zn) of Ekranic Technosols by applying indicators such as geoaccumulation index (I geo ), enrichment factor (EF), and pollution load index (PLI), which allowed to determine quantitatively the impact of the soil sealing degree on the content of heavy metals and to distinguish natural from anthropogenic sources of origin of heavy metals. In general, 42 soils from different parts of the city of Toruń (NW Poland) were sampled and divided into three groups according to the degree of soil sealing: completely sealed with asphalt or concrete (A), semi-permeable (partially sealed with cobblestones and concrete paving slabs (B)), and reference (non-sealed) (C). The results indicate that the artificial sealing in urban areas slightly affects the content of heavy metals in soils. However, based on PLI, I geo , and EF, it was found that the sealing has influence on soil properties and unsealed soil is the most exposed to the accumulation of pollutants.

  19. De-novo discovery of differentially abundant transcription factor binding sites including their positional preference.

    Science.gov (United States)

    Keilwagen, Jens; Grau, Jan; Paponov, Ivan A; Posch, Stefan; Strickert, Marc; Grosse, Ivo

    2011-02-10

    Transcription factors are a main component of gene regulation as they activate or repress gene expression by binding to specific binding sites in promoters. The de-novo discovery of transcription factor binding sites in target regions obtained by wet-lab experiments is a challenging problem in computational biology, which has not been fully solved yet. Here, we present a de-novo motif discovery tool called Dispom for finding differentially abundant transcription factor binding sites that models existing positional preferences of binding sites and adjusts the length of the motif in the learning process. Evaluating Dispom, we find that its prediction performance is superior to existing tools for de-novo motif discovery for 18 benchmark data sets with planted binding sites, and for a metazoan compendium based on experimental data from micro-array, ChIP-chip, ChIP-DSL, and DamID as well as Gene Ontology data. Finally, we apply Dispom to find binding sites differentially abundant in promoters of auxin-responsive genes extracted from Arabidopsis thaliana microarray data, and we find a motif that can be interpreted as a refined auxin responsive element predominately positioned in the 250-bp region upstream of the transcription start site. Using an independent data set of auxin-responsive genes, we find in genome-wide predictions that the refined motif is more specific for auxin-responsive genes than the canonical auxin-responsive element. In general, Dispom can be used to find differentially abundant motifs in sequences of any origin. However, the positional distribution learned by Dispom is especially beneficial if all sequences are aligned to some anchor point like the transcription start site in case of promoter sequences. We demonstrate that the combination of searching for differentially abundant motifs and inferring a position distribution from the data is beneficial for de-novo motif discovery. Hence, we make the tool freely available as a component of the open

  20. Induced Systemic Tolerance to Multiple Stresses Including Biotic and Abiotic Factors by Rhizobacteria

    Directory of Open Access Journals (Sweden)

    Sung-Je Yoo

    2017-06-01

    Full Text Available Recently, global warming and drastic climate change are the greatest threat to the world. The climate change can affect plant productivity by reducing plant adaptation to diverse environments including frequent high temperature; worsen drought condition and increased pathogen transmission and infection. Plants have to survive in this condition with a variety of biotic (pathogen/pest attack and abiotic stress (salt, high/low temperature, drought. Plants can interact with beneficial microbes including plant growth-promoting rhizobacteria, which help plant mitigate biotic and abiotic stress. This overview presents that rhizobacteria plays an important role in induced systemic resistance (ISR to biotic stress or induced systemic tolerance (IST to abiotic stress condition; bacterial determinants related to ISR and/or IST. In addition, we describe effects of rhizobacteria on defense/tolerance related signal pathway in plants. We also review recent information including plant resistance or tolerance against multiple stresses (bioticabiotic. We desire that this review contribute to expand understanding and knowledge on the microbial application in a constantly varying agroecosystem, and suggest beneficial microbes as one of alternative environment-friendly application to alleviate multiple stresses.

  1. Soils

    Science.gov (United States)

    Emily Moghaddas; Ken Hubbert

    2014-01-01

    When managing for resilient forests, each soil’s inherent capacity to resist and recover from changes in soil function should be evaluated relative to the anticipated extent and duration of soil disturbance. Application of several key principles will help ensure healthy, resilient soils: (1) minimize physical disturbance using guidelines tailored to specific soil types...

  2. Toluene Removal from Sandy Soils via In Situ Technologies with an Emphasis on Factors Influencing Soil Vapor Extraction

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Amin

    2014-01-01

    Full Text Available The integration of bioventing (BV and soil vapor extraction (SVE appears to be an effective combination method for soil decontamination. This paper serves two main purposes: it evaluates the effects of soil water content (SWC and air flow rate on SVE and it investigates the transition regime between BV and SVE for toluene removal from sandy soils. 96 hours after air injection, more than 97% removal efficiency was achieved in all five experiments (carried out for SVE including 5, 10, and 15% for SWC and 250 and 500 mL/min for air flow rate on SVE. The highest removal efficiency (>99.5% of toluene was obtained by the combination of BV and SVE (AIBV: Air Injection Bioventing after 96 h of air injection at a constant flow rate of 250 mL/min. It was found that AIBV has the highest efficiency for toluene removal from sandy soils and can remediate the vadose zone effectively to meet the soil guideline values for protection of groundwater.

  3. Toluene removal from sandy soils via in situ technologies with an emphasis on factors influencing soil vapor extraction.

    Science.gov (United States)

    Amin, Mohammad Mehdi; Hatamipour, Mohammad Sadegh; Momenbeik, Fariborz; Nourmoradi, Heshmatollah; Farhadkhani, Marzieh; Mohammadi-Moghadam, Fazel

    2014-01-01

    The integration of bioventing (BV) and soil vapor extraction (SVE) appears to be an effective combination method for soil decontamination. This paper serves two main purposes: it evaluates the effects of soil water content (SWC) and air flow rate on SVE and it investigates the transition regime between BV and SVE for toluene removal from sandy soils. 96 hours after air injection, more than 97% removal efficiency was achieved in all five experiments (carried out for SVE) including 5, 10, and 15% for SWC and 250 and 500 mL/min for air flow rate on SVE. The highest removal efficiency (>99.5%) of toluene was obtained by the combination of BV and SVE (AIBV: Air Injection Bioventing) after 96 h of air injection at a constant flow rate of 250 mL/min. It was found that AIBV has the highest efficiency for toluene removal from sandy soils and can remediate the vadose zone effectively to meet the soil guideline values for protection of groundwater.

  4. 60Co Transfer Factor From Lutosol Soil To Leafy Vegetable (Ipomea reptans poir)

    International Nuclear Information System (INIS)

    Leli-Nirwani; Jumaher; Wahyudi

    2003-01-01

    It has been conducted 60 Co transfer study from Lutosol soil to leafy vegetable plant by using pot treatment system. The aim of the research is to obtain data of the transfer factor of 60 Co from lutosol soil to leafy vegetable plant. Pot experiment was carried out by using the complete random design to evaluate two treatment, namely soil with 60 Co and without 60 Co (as a control). 60 Co concentration was with 6.1371 kBq/pot. Tested plant and control plant amount to 12 pots. Each pot contains 1 kg of soil. After harvesting, the weight of dry plant was determined and was conducted with Spectrometer Gamma to 60 Co concentration in dry plant and dry soil. Transfer factor was found to between 0.02 and 0.68 and the average is 0.2068. (author)

  5. On the structural factors of soil humic matter related to soil water repellence in fire-affected soils

    Science.gov (United States)

    Almendros, G.; González-Vila, F. J.; González-Pérez, J. A.; Knicker, H.; De la Rosa, J. M.; Dettweiler, C.; Hernández, Z.

    2012-04-01

    In order to elucidate the impact of forest fires on physical and chemical properties of the soils as well as on the chemical composition of the soil organic matter, samples from two Mediterranean soils with contrasted characteristics and vegetation (O horizon, Lithic Leptosols under Quercus ilex and Pinus pinaster) and one agricultural soil (Ap horizon, Luvisol) were heated at 350 °C in laboratory conditions for three successive steps up to 600 s. The C- and N-depletion in the course of the heating showed small changes up to an oxidation time of 300 s. On the other side, and after 600 s, considerable C-losses (between 21% in the Luvisol and 50% in the Leptosols) were observed. The relatively low N-depletion ca. 4% (Luvisol) and 21% (Leptosol under pine) suggested preferential loss of C and the subsequent relative enrichment of nitrogen. Paralleling the progressive depletion of organic matter, the Leptosols showed a significant increase of both pH and electrical conductivity. The former change paralleled the rapid loss of carboxyl groups, whereas the latter point to the relative enrichment of ash with a bearing on the concentration of inorganic ions, which could be considered a positive effect for the post-fire vegetation. The quantitative and qualitative analyses by solid-state 13C NMR spectra of the humic fractions in the samples subjected to successive heating times indicate significant concentration of aromatic structures newly-formed in the course of the dehydration and cyclization of carbohydrates (accumulation of black carbon-type polycyclic aromatic structures), and probably lipids and peptides. The early decarboxylation, in addition to the depletion of O-alkyl hydrophilic constituents and further accumulation of secondary aromatic structures resulted in the dramatic increase in the soil water drop penetration time. It was confirmed that this enhancement of the soil hydrophobicity is not related to an increased concentration of soil free lipid, but is

  6. A proposal for soil cover and management factor (C) for RUSLE in vineyards with different soil management across Europe

    Science.gov (United States)

    Gómez, José Alfonso; Biddoccu, Marcella; Guzman, Gema; Bauer, Thomas; Strauss, Peter; Winter, Silvia; Zaller, Johann; Cavallo, Eugenio

    2017-04-01

    The Revised Universal Soil Loss Equation RUSLE (Dabney et al., 2012) is commonly used to estimate rates of soil erosion caused by rainfall and its associated overland flow on cropland and many other disturbed and undisturbed lands. Several studies have been focused on the evaluation of erosion risk in vineyards across Europe, which has four countries, France, Italy, Spain and Portugal, among the world's top ten vine growers. Other European countries, such as Romania, Greece, Austria, Serbia and Hungary, also have significant surface devoted to vineyards (FAO, 2014). However, literature shows a wide variability among C factors from different sources (Auerswald and Schwab, 1999; Kouli et al., 2009; Novara et al., 2011; Pacheco et al., 2014; Rodrigo Comino et al., 2016) that complicates their interpretation and use outside the area where they were developed. Gómez et al. (2016) presented a simplified erosion prediction model based on RUSLE, ORUSCAL, to demonstrate the possibility to calibrate RUSLE for a broad range of management conditions in vineyards with limited datasets. This approach have already been pursued successfully in olives (Gómez et al. 2003, Vanwalleghem et al., 2011). This communication reports the results of an evaluation of the calibration strategies and model predictions of ORUSCAL using a long-term experiment dataset (Bidoccu et al., 2016) in a vineyard in Northern Italy, and its implementation to develop soil cover and management factors (C) in three different soil, climate and management conditions across Europe: Southern Spain, Northern Italy and Austria. The communication, furthermore, explores and discusses of the application of the ORUSCAL model to additional vineyards areas in France and Romania in the context of the Vinedivers project (www.vinedivers.eu). Keywords: vineyard, erosion, soil management, RUSLE, model. References Auerswald K., Schwab, S. 1999. Erosion risk (C factor) of different viticultural practices. Vitic. Enol. Sci.54

  7. Soil Nitrogen Storage, Distribution, and Associated Controlling Factors in the Northeast Tibetan Plateau Shrublands

    Directory of Open Access Journals (Sweden)

    Xiuqing Nie

    2017-11-01

    Full Text Available Although the soils in the Tibetan Plateau shrublands store large amounts of total nitrogen (N, the estimated values remain uncertain because of spatial heterogeneity and a lack of field observations. In this study, we quantified the regional soil N storage, spatial and vertical density distributions, and related climatic controls using 183 soil profiles sampled from 61 sites across the Northeast Tibetan Plateau shrublands during the period of 2011–2013. Our analysis revealed a soil N storage value of 132.40 Tg at a depth of 100 cm, with an average density of 1.21 kg m−2. Soil N density was distributed at greater levels in alpine shrublands, compared with desert shrublands. Spatially, soil N densities decreased from south to north and from east to west, and, vertically, the soil N in the upper 30 and 50 cm accounted for 42% and 64% of the total soil N stocks in the Tibetan Plateau. However, compared with desert shrublands, the surface layers in alpine shrublands exhibited a larger distribution of soil N stocks. Overall, the soil N density in the top 30 cm increased significantly with the mean annual precipitation (MAP and tended to decrease with the mean annual temperature (MAT, although the dominant climatic controls differed among shrubland types. Specifically, MAP in alpine shrublands, and MAT in desert shrubland, had a weak effect on N density. Soil pH can significant affect soil N density in the Tibetan Plateau shrublands. In conclusion, changes in soil N density should be monitored over the long term to provide accurate information about the effects of climatic factors.

  8. Transfer factors of 134Cs for olive and orange trees grown on different soils

    International Nuclear Information System (INIS)

    Skarlou, V.; Nobeli, C.; Anoussis, J.; Haidouti, C.; Papanicolaou, E.

    1999-01-01

    Transfer factors (TF) of 134 Cs to olive and citrus trees grown on two different soils, were determined for a 3-year greenhouse experiment. Two-year-old trees were transplanted with their entire rootball into large pots containing the contaminated soil (110 kg pot -1 ). The soil was transferred to each pot in layers on the top of which 134 Cs as CsCl was dripped (18.5 MBq pot -1 ). For both evergreen trees, soil type significantly influenced radiocaesium transfer. 134 Cs concentration was lower for the calcareous-heavy soil than for the acid-light soil. Transfer factors of orange trees were higher than those of olive trees in the acid-light soil. Although a significant amount of 134 Cs was measured in olives grown on the acid-light soil, no 134 Cs was detected in the unprocessed olive oil when an oil fraction (5% f.w.) was extracted. On the contrary the edible part of the oranges showed the highest 134 Cs concentration of all plant parts. The relationship between 134 Cs uptake and potassium content in the different plant compartments was also studied when selected trees were cut down. The potassium concentration in the plants was not significantly different between the trees growing in the two types of soil in spite of the big differences in the 134 Cs uptake in the two soils. TF values and potassium content in the different plant compartments of each tree were highly correlated. For both crops transfer factors as well as potassium content were the highest in the developing plant parts (new leaves and branches, flowers). The transfer factors of 134 Cs for the studied trees are in the same order of magnitude as the values of annual crops grown under similar conditions. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  9. Soil types and limiting factors in agricultural production in the San Fernando district, Tamaulipas, Mexico

    International Nuclear Information System (INIS)

    Espinosa Ramirez, M.; Garza Cedillo, R.; Andrade limas, E.; Belmonte Serrato, F.

    2009-01-01

    The limiting factors in agricultural production, defined as those properties and characteristics of the geographical environment that influence the development of crops, can be diverse and are grouped with the physical environment of soil. They are the result of soil characteristics and soil degradation processes by anthropogenic influence. Due to the above, the objective of this study was to identify and surveying the limitative factors to agricultural production, as well as to define its ability land use capacity in San Fernando district, Tamaulipas. (Author) 7 refs.

  10. Scale-location specific relations between soil nutrients and topographic factors in the Fen River Basin, Chinese Loess Plateau

    Science.gov (United States)

    Zhu, Hongfen; Bi, Rutian; Duan, Yonghong; Xu, Zhanjun

    2017-06-01

    Understanding scale- and location-specific variations of soil nutrients in cultivated land is a crucial consideration for managing agriculture and natural resources effectively. In the present study, wavelet coherency was used to reveal the scale-location specific correlations between soil nutrients, including soil organic matter (SOM), total nitrogen (TN), available phosphorus (AP), and available potassium (AK), as well as topographic factors (elevation, slope, aspect, and wetness index) in the cultivated land of the Fen River Basin in Shanxi Province, China. The results showed that SOM, TN, AP, and AK were significantly inter-correlated, and that the scales at which soil nutrients were correlated differed in different landscapes, and were generally smaller in topographically rougher terrain. All soil nutrients but TN were significantly influenced by the wetness index at relatively large scales (32-72 km) and AK was significantly affected by the aspect at large scales at partial locations, showing localized features. The results of this study imply that the wetness index should be taken into account during farming practices to improve the soil nutrients of cultivated land in the Fen River Basin at large scales.

  11. Human factors design of nuclear power plant control rooms including computer-based operator aids

    International Nuclear Information System (INIS)

    Bastl, W.; Felkel, L.; Becker, G.; Bohr, E.

    1983-01-01

    The scientific handling of human factors problems in control rooms began around 1970 on the basis of safety considerations. Some recent research work deals with the development of computerized systems like plant balance calculation, safety parameter display, alarm reduction and disturbance analysis. For disturbance analysis purposes it is necessary to homogenize the information presented to the operator according to the actual plant situation in order to supply the operator with the information he most urgently needs at the time. Different approaches for solving this problem are discussed, and an overview is given on what is being done. Other research projects concentrate on the detailed analysis of operators' diagnosis strategies in unexpected situations, in order to obtain a better understanding of their mental processes and the influences upon them when such situations occur. This project involves the use of a simulator and sophisticated recording and analysis methods. Control rooms are currently designed with the aid of mock-ups. They enable operators to contribute their experience to the optimization of the arrangement of displays and controls. Modern control rooms are characterized by increasing use of process computers and CRT (Cathode Ray Tube) displays. A general concept for the integration of the new computerized system and the conventional control panels is needed. The technical changes modify operators' tasks, and future ergonomic work in nuclear plants will need to consider the re-allocation of function between man and machine, the incorporation of task changes in training programmes, and the optimal design of information presentation using CRTs. Aspects of developments in control room design are detailed, typical research results are dealt with, and a brief forecast of the ergonomic contribution to be made in the Federal Republic of Germany is given

  12. The Validation Of Influence Factors To DDT Concentration In Soil

    International Nuclear Information System (INIS)

    Kamal, Zainul; Poernomo, Herry

    2000-01-01

    Determination concentration of DDT in humidified land's and rising intensity has been done. The amount of natural soil was filled in poliethylene tube, and the amount of humadified soil was filled in order poliethylene tube. The solution of DDT-C sub.14 with volume of 10 ml and activity of 10 muCi was increased in those tube respectively, the latter it was resident for many time under shine. Sample of soil was took first week to sixthweek, it was crushed to reach homogenous, then it was counted by liquid scintillation counter. The experiment result indicated that the DDT content in the unilluminated soil for 1 week is < 0.1 ppb, for 2 week is 0.19 n 0.01 ppb, for 3 week is 1.95 n 0.32 ppb, for 4 week is 14.07 n 0.14 ppb, for 5 week is 3.67 n 0.21 ppb and for 6 week is 2.28 n 0.09 ppb. The DDT content in the humidified soil without sun illumination for 1 week is 0.25 n 0.07 ppb, for 2 week is 6.34 n 0.19 ppb, for 3 week is 9.33 n 0.80 ppb, for 4 week is 12.36 n 0.17 ppb, for 5 week is 4.58 n 0.15 ppb and for 6 week is 2.01 n 0.55 ppb. The DDT content in the natural soil illuminated by VIS for 1 week is 0.74 n 0.08 ppb, for 2 week is 7.48 n 0.14 ppb, for 3 week is 4.06 n 0.28 ppb, for 4 week is 13.16 n 0.20 ppb, for 5 week is 5.00 n 0.70 ppb and for 6 week is 2.03 n 0.03 ppb

  13. Optimum Design of Braced Steel Space Frames including Soil-Structure Interaction via Teaching-Learning-Based Optimization and Harmony Search Algorithms

    Directory of Open Access Journals (Sweden)

    Ayse T. Daloglu

    2018-01-01

    Full Text Available Optimum design of braced steel space frames including soil-structure interaction is studied by using harmony search (HS and teaching-learning-based optimization (TLBO algorithms. A three-parameter elastic foundation model is used to incorporate the soil-structure interaction effect. A 10-storey braced steel space frame example taken from literature is investigated according to four different bracing types for the cases with/without soil-structure interaction. X, V, Z, and eccentric V-shaped bracing types are considered in the study. Optimum solutions of examples are carried out by a computer program coded in MATLAB interacting with SAP2000-OAPI for two-way data exchange. The stress constraints according to AISC-ASD (American Institute of Steel Construction-Allowable Stress Design, maximum lateral displacement constraints, interstorey drift constraints, and beam-to-column connection constraints are taken into consideration in the optimum design process. The parameters of the foundation model are calculated depending on soil surface displacements by using an iterative approach. The results obtained in the study show that bracing types and soil-structure interaction play very important roles in the optimum design of steel space frames. Finally, the techniques used in the optimum design seem to be quite suitable for practical applications.

  14. A Dataset for Three-Dimensional Distribution of 39 Elements Including Plant Nutrients and Other Metals and Metalloids in the Soils of a Forested Headwater Catchment.

    Science.gov (United States)

    Wu, B; Wiekenkamp, I; Sun, Y; Fisher, A S; Clough, R; Gottselig, N; Bogena, H; Pütz, T; Brüggemann, N; Vereecken, H; Bol, R

    2017-11-01

    Quantification and evaluation of elemental distribution in forested ecosystems are key requirements to understand element fluxes and their relationship with hydrological and biogeochemical processes in the system. However, datasets supporting such a study on the catchment scale are still limited. Here we provide a dataset comprising spatially highly resolved distributions of 39 elements in soil profiles of a small forested headwater catchment in western Germany () to gain a holistic picture of the state and fluxes of elements in the catchment. The elements include both plant nutrients and other metals and metalloids that were predominately derived from lithospheric or anthropogenic inputs, thereby allowing us to not only capture the nutrient status of the catchment but to also estimate the functional development of the ecosystem. Soil samples were collected at high lateral resolution (≤60 m), and element concentrations were determined vertically for four soil horizons (L/Of, Oh, A, B). From this, a three-dimensional view of the distribution of these elements could be established with high spatial resolution on the catchment scale in a temperate natural forested ecosystem. The dataset can be combined with other datasets and studies of the TERENO (Terrestrial Environmental Observatories) Data Discovery Portal () to reveal elemental fluxes, establish relations between elements and other soil properties, and/or as input for modeling elemental cycling in temperate forested ecosystems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  15. Tree species is the major factor explaining C:N ratios in European forest soils

    DEFF Research Database (Denmark)

    Cools, Nathalie; Vesterdal, Lars; De Vos, Bruno

    2014-01-01

    The C:N ratio is considered as an indicator of nitrate leaching in response to high atmospheric nitrogen (N) deposition. However, the C:N ratio is influenced by a multitude of other site-related factors. This study aimed to unravel the factors determining C:N ratios of forest floor, mineral soil...... mineral soil layers it was the humus type. Deposition and climatic variables were of minor importance at the European scale. Further analysis for eight main forest tree species individually, showed that the influence of environmental variables on C:N ratios was tree species dependent. For Aleppo pine...... and peat top soils in more than 4000 plots of the ICP Forests large-scale monitoring network. The first objective was to quantify forest floor, mineral and peat soil C:N ratios across European forests. Secondly we determined the main factors explaining this C:N ratio using a boosted regression tree...

  16. Co-contaminants and factors affecting the sorption behaviour of two sulfonamides in pasture soils

    International Nuclear Information System (INIS)

    Srinivasan, Prakash; Sarmah, Ajit K.; Manley-Harris, Merilyn

    2013-01-01

    We investigated the effect of soil pH, organic carbon, ionic strength and steroid hormones on the sorption of sulfamethoxazole (SMO) and sulfachloropyridazine (SCP) in three pastoral soils of New Zealand. A model linking sorbate speciation with species-specific sorption coefficients describing the pH dependence of the apparent sorption coefficients was used to derive the fraction of each species of SMO. All soils displayed a decrease in sorption when pH was increased, with SMO exhibiting the highest sorption at pH 2. The cationic form of SMO appeared to sorb more close to pH ≥ pK a1 and, when pH ≥ pK a2 (6.5, 7.5 and 8.5) the anionic species seems to dominate, however, its sorption affinity to all soils was low. SMO sorption was affected by ionic strengths and organic carbon content, while the presence of hormones showed only a subtle decrease in SCP sorption in a selected model pasture soil. -- Highlights: •The effect of OC content on sulfamethoxazole sorption is nullified by the pH effect. •Steroid hormone has a subtle influence on the sulfachloropyridazine sorption in pastoral soil. •Increased hormone concentrations decrease sulfachloropyridazine sorption in soils. -- Sorption affinity of SMO and SCP are strongly governed by multitude of factors, and variations in these factors can be significant when manure and fertilisers are added to soil

  17. Accumulation of Heavy Metals in Roadside Soil in Urban Area and the Related Impacting Factors.

    Science.gov (United States)

    Wang, Meie; Zhang, Haizhen

    2018-05-24

    Heavy metal contamination in roadside soil due to traffic emission has been recognized for a long time. However, seldom has been reported regarding identification of critical factors influencing the accumulation of heavy metals in urban roadside soils due to the frequent disturbances such as the repair of damaged roads and green belt maintanance. Heavy metals in the roadside soils of 45 roads in Xihu district, Hangzhou city were investigated. Results suggested the accumulation of Cu, Pb, Cd, Cr, and Zn in roadside soil was affected by human activity. However, only two sites had Pb and Zn excessing the standards for residential areas, respectively, according to Chinese Environmental Quality Standards for soils. The concentrations of Cu, Pb, Cd, and Zn were significantly and positively correlated to soil pH and organic matter. An insignificant correlation between the age of the roads or vegetation cover types and the concentration of heavy metals was found although they were reported closely relating to the accumulation of heavy metals in roadside soils of highways. The highest Pb, Cd, and Cr taking place in sites with heavy traffic and significant differences in the concentrations of Cu, Pb, Cd, and Zn among the different categories of roads suggested the contribution of traffic intensity. However, it was difficult to establish a quantitative relationship between traffic intensity and the concentrations of heavy metals in the roadside soil. It could be concluded that impaction of traffic emission on the accumulation of heavy metals in roadside soils in urban area was slight and soil properties such as pH and organic matters were critical factors influencing the retention of heavy metals in soils.

  18. Scientific case studies in land-use driven soil erosion in the central United States: Why soil potential and risk concepts should be included in the principles of soil health

    Directory of Open Access Journals (Sweden)

    Benjamin L. Turner

    2018-03-01

    Full Text Available Despite recent improvements in overall soil health gained through conservation agriculture, which has become a global priority in agricultural systems, soil and water-related externalities (e.g., wind and water erosion continue to persist or worsen. Using an inductive, systems approach, we tested the hypothesis that such externalities persist due to expansion of cultivation onto areas unsuitable for sustained production. To test this hypothesis, a variety of data sources and analyses were used to uncover the land and water resource dynamics underlying noteworthy cases of soil erosion (either wind or water and hydrological effects (e.g., flooding, shifting hydrographs throughout the central United States. Given the evidence, we failed to reject the hypothesis that cultivation expansion is contributing to increased soil and water externalities, since significant increases in cultivation on soils with severe erosion limitations were observed everywhere the externalities were documented. We discuss the case study results in terms of land use incentives (e.g., policy, economic, and biophysical, developing concepts of soil security, and ways to utilize case studies such as those presented to better communicate the value of soil and water resource conservation. Incorporating the tenets of soil potential and soil risk into soil health evaluations and cultivation decision-making is needed to better match the soil resource with land use and help avoid more extreme soil and water-related externalities.

  19. Soil-soil solution distribution coefficient of soil organic matter is a key factor for that of radioiodide in surface and subsurface soils.

    Science.gov (United States)

    Unno, Yusuke; Tsukada, Hirofumi; Takeda, Akira; Takaku, Yuichi; Hisamatsu, Shun'ichi

    2017-04-01

    We investigated the vertical distribution of the soil-soil-solution distribution coefficients (K d ) of 125 I, 137 Cs, and 85 Sr in organic-rich surface soil and organic-poor subsurface soil of a pasture and an urban forest near a spent-nuclear-fuel reprocessing plant in Rokkasho, Japan. K d of 137 Cs was highly correlated with water-extractable K + . K d of 85 Sr was highly correlated with water-extractable Ca 2+ and SOC. K d of 125 I - was low in organic-rich surface soil, high slightly below the surface, and lowest in the deepest soil. This kinked distribution pattern differed from the gradual decrease of the other radionuclides. The thickness of the high- 125 I - K d middle layer (i.e., with high radioiodide retention ability) differed between sites. K d of 125 I - was significantly correlated with K d of soil organic carbon. Our results also showed that the layer thickness is controlled by the ratio of K d -OC between surface and subsurface soils. This finding suggests that the addition of SOC might prevent further radioiodide migration down the soil profile. As far as we know, this is the first report to show a strong correlation of a soil characteristic with K d of 125 I - . Further study is needed to clarify how radioiodide is retained and migrates in soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Fire as a Factor of Variation of Soil Respiration in Amazonia of Peru

    Science.gov (United States)

    Suarez, L.; Kruijt, B.

    2007-05-01

    Severe changes are affecting the role of Amazonia in the Earth system. One of these possible effects could be the modification of the relevance of soil in the carbon cycle. In this sense, fire is an important factor for mobilizing C from the soil to the atmosphere, mainly as CO2. This could have an important effect in the global warming. Our proposal will evaluate the variation of the soil respiration related to the seasonality and the fire effects on soils in the Amazonia of Peru and Brasil. In experimental parcels of four locations of Peru with different vegetation cover (forest and pasture), we will measure soil respiration along with the organic carbon and the microbial biomass of soils during campaigns of wet and dry seasons, with complementary measurements of soil temperature, water and nutrient content. Also, we will reproduce a fire experiment simulating local activity of "slash and burn" to evaluate fire effects. Measurements will be taken after the soil cooled and 1, 3, 5, 7 and 10 days after the fire. Additionally, the carbon stock of the subparcels will be evaluated. Evaluation of the variations of CO2 fluxes and the capacity of adaptation to fire and water content will be done through the comparisons of the different locations, type of soils and concentration of available N as an indicator of nutrient content.

  1. Atmospheric dust additions as a soil formation factor

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Hernandez, J. L.; Ruoss, J.

    2009-07-01

    The Mediterranean area is distinguished by a least four features that determine the nature of its soils. These are its climate, its mountains, the addition of exogenous dust and ongoing anthropogenic effects. We here present three cases in which the influence of atmospheric dust additions can be detected in the soils of representative circum-Saharan contexts the Canary Islands, Betic intramontane depressions, and the Sierra Bermeja peridotite massif (Malaga). The unique position of the Canary Islands determines important rates of dust deposit, largely depending on position on the relief. the nature of the dust contrasts with the rocky substratum of the islands, and the marine and volcanic context can also affect the nature of the deposits. The numerous, extensive intramontane basins of the Betic Cordilleras act as large captors of atmospheric dust, with rates similar to those found in the Canary archipelago. The carbonate content of these exogenous additions represents a significant components that should be taken into account when establishing the carbonate accumulation regime in these soils. (Author) 13 refs.

  2. Which Factors Determine Metal Accumulation in Agricultural Soils in the Severely Human-Coupled Ecosystem?

    Science.gov (United States)

    Xu, Li; Cao, Shanshan; Wang, Jihua; Lu, Anxiang

    2016-05-17

    Agricultural soil is typically an important component of urban ecosystems, contributing directly or indirectly to the general quality of human life. To understand which factors influence metal accumulation in agricultural soils in urban ecosystems is becoming increasingly important. Land use, soil type and urbanization indicators all account for considerable differences in metal accumulation in agricultural soils, and the interactions between these factors on metal concentrations were also examined. Results showed that Zn, Cu, and Cd concentrations varied significantly among different land use types. Concentrations of all metals, except for Cd, were higher in calcareous cinnamon soil than in fluvo-aquic soil. Expansion distance and road density were adopted as urbanization indicators, and distance from the urban center was significantly negatively correlated with concentrations of Hg, and negatively correlated with concentrations of Zn, and road density was positively correlated with Cd concentrations. Multivariate analysis of variance indicated that Hg concentration was significantly influenced by the four-way interaction among all factors. The results in this study provide basic data to support the management of agricultural soils and to help policy makers to plan ahead in Beijing.

  3. Spatial variability and its main controlling factors of the permafrost soil-moisture on the northern-slope of Bayan Har Mountains in Qinghai-Tibet Plateau

    Science.gov (United States)

    Cao, W.; Sheng, Y.

    2017-12-01

    The soil moisture movement is an important carrier of material cycle and energy flow among the various geo-spheres in the cold regions. It is very critical to protect the alpine ecology and hydrologic cycle in Qinghai-Tibet Plateau. Especially, it becomes one of the key problems to reveal the spatial-temporal variability of soil moisture movement and its main influence factors in earth system science. Thus, this research takes the north slope of Bayan Har Mountains in Qinghai-Tibet Plateau as a case study. The present study firstly investigates the change of permafrost moisture in different slope positions and depths. Based on this investigation, this article attempts to investigate the spatial variability of permafrost moisture and identifies the key influence factors in different terrain conditions. The method of classification and regression tree (CART) is adopted to identify the main controlling factors influencing the soil moisture movement. And the relationships between soil moisture and environmental factors are revealed by the use of the method of canonical correspondence analysis (CCA). The results show that: 1) the change of the soil moisture on the permafrost slope is divided into 4 stages, including the freezing stability phase, the rapid thawing phase, the thawing stability phase and the fast freezing phase; 2) this greatly enhances the horizontal flow in the freezing period due to the terrain slope and the freezing-thawing process. Vertical migration is the mainly form of the soil moisture movement. It leads to that the soil-moisture content in the up-slope is higher than that in the down-slope. On the contrary, the soil-moisture content in the up-slope is lower than that in the down-slope during the melting period; 3) the main environmental factors which affect the slope-permafrost soil-moisture are elevation, soil texture, soil temperature and vegetation coverage. But there are differences in the impact factors of the soil moisture in different

  4. SMAP Multi-Temporal Soil Moisture and Vegetation Optical Depth Retrievals in Vegetated Regions Including Higher-Order Soil-Canopy Interactions

    Science.gov (United States)

    Feldman, A.; Akbar, R.; Konings, A. G.; Piles, M.; Entekhabi, D.

    2017-12-01

    The Soil Moisture Active Passive (SMAP) mission utilizes a zeroth order radiative transfer model, known as the tau-omega model, to retrieve soil moisture from microwave brightness temperature observations. This model neglects first order scattering which is significant at L-Band in vegetated regions, or 30% of land cover. Previous higher order algorithms require extensive in-situ measurements and characterization of canopy layer physical properties. We propose a first order retrieval algorithm that approximately characterizes the eight first order emission pathways using rough surface reflectivity, vegetation optical depth (VOD), and scattering albedo terms. The recently developed Multi-Temporal Dual Channel Algorithm (MT-DCA) then retrieves these three parameters in a forward model without ancillary information under the assumption of temporally static albedo and constant vegetation water content between three day SMAP revisits. The approximated scattering terms are determined to be conservative estimates of analytically derived first order scattering terms. In addition, we find the first order algorithm to be more sensitive to surface emission than the tau-omega model. The simultaneously retrieved VOD, previously demonstrated to be proportional to vegetation water content, can provide insight into vegetation dynamics in regions with significant phenology. Specifically, dry tropical forests exhibit an increase in VOD during the dry season in alignment with prior studies that suggest that certain vegetative species green up during the dry season despite limited water availability. VOD retrieved using the first order algorithm and MT-DCA framework can therefore contribute to understanding of tropical forests' role in the carbon, energy, and water cycles, which has yet to be fully explained.

  5. Vertical distribution of soil saturated hydraulic conductivity and its influencing factors in a small karst catchment in Southwest China.

    Science.gov (United States)

    Fu, Tonggang; Chen, Hongsong; Zhang, Wei; Nie, Yunpeng; Wang, Kelin

    2015-03-01

    Saturated hydraulic conductivity (Ks) is one of the most important soil hydraulic parameters influencing hydrological processes. This paper aims to investigate the vertical distribution of Ks and to analyze its influencing factors in a small karst catchment in Southwest China. Ks was measured in 23 soil profiles for six soil horizons using a constant head method. These profiles were chosen in different topographical locations (upslope, downslope, and depression) and different land-use types (forestland, shrubland, shrub-grassland, and farmland). The influencing factors of Ks, including rock fragment content (RC), bulk density (BD), capillary porosity (CP), non-capillary porosity (NCP), and soil organic carbon (SOC), were analyzed by partial correlation analysis. The mean Ks value was higher in the entire profile in the upslope and downslope, but lower value, acting as a water-resisting layer, was found in the 10-20 cm soil depth in the depression. Higher mean Ks values were found in the soil profiles in the forestland, shrubland, and shrub-grassland, but lower in the farmland. These results indicated that saturation-excess runoff could occur primarily in the hillslopes but infiltration-excess runoff in the depression. Compared with other land-use types, surface runoff is more likely to occur in the farmlands. RC had higher correlation coefficients with Ks in all categories concerned except in the forestland and farmland with little or no rock fragments, indicating that RC was the dominant influencing factor of Ks. These results suggested that the vertical distributions of Ks and RC should be considered for hydrological modeling in karst areas.

  6. Intrinsic factors of Peltigera lichens influence the structure of the associated soil bacterial microbiota.

    Science.gov (United States)

    Leiva, Diego; Clavero-León, Claudia; Carú, Margarita; Orlando, Julieta

    2016-11-01

    Definition of lichens has evolved from bi(tri)partite associations to multi-species symbioses, where bacteria would play essential roles. Besides, although soil bacterial communities are known to be affected by edaphic factors, when lichens grow upon them these could become less preponderant. We hypothesized that the structure of both the lichen microbiota and the microbiota in the soil underneath lichens is shaped by lichen intrinsic and extrinsic factors. In this work, intrinsic factors corresponded to mycobiont and cyanobiont identities of Peltigera lichens, metabolite diversity and phenoloxidase activity and extrinsic factors involved the site of the forest where lichens grow. Likewise, the genetic and metabolic structure of the lichen and soil bacterial communities were analyzed by fingerprinting. Among the results, metabolite diversity was inversely related to the genetic structure of bacterial communities of lichens and soils, highlighting the far-reaching effect of these substances; while phenoloxidase activity was inversely related to the metabolic structure only of the lichen bacterial microbiota, presuming a more limited effect of the products of these enzymes. Soil bacterial microbiota was different depending on the site and, strikingly, according to the cyanobiont present in the lichen over them, which could indicate an influence of the photobiont metabolism on the availability of soil nutrients. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Evaluation of Seismic Response Trends from Long-Term Monitoring of Two Instrumented RC Buildings Including Soil-Structure Interaction

    Directory of Open Access Journals (Sweden)

    Faheem Butt

    2012-01-01

    Full Text Available This paper presents analyses of the seismic responses of two reinforced concrete buildings monitored for a period of more than two years. One of the structures was a three-storey reinforced concrete (RC frame building with a shear core, while the other was a three-storey RC frame building without a core. Both buildings are part of the same large complex but are seismically separated from the rest of it. Statistical analysis of the relationships between maximum free field accelerations and responses at different points on the buildings was conducted and demonstrated strong correlation between those. System identification studies using recorded accelerations were undertaken and revealed that natural frequencies and damping ratios of the building structures vary during different earthquake excitations. This variation was statistically examined and relationships between identified natural frequencies and damping ratios, and the peak response acceleration at the roof level were developed. A general trend of decreasing modal frequencies and increasing damping ratios was observed with increased level of shaking and response. Moreover, the influence of soil structure interaction (SSI on the modal characteristics was evaluated. SSI effects decreased the modal frequencies and increased some of the damping ratios.

  8. Socio-Economic Factors Assessment Affecting the Adoption of Soil Conservation Technologies on Rwenzori Mountain

    Directory of Open Access Journals (Sweden)

    Nabalegwa Wambede Muhamud

    2015-06-01

    Full Text Available This study analysed the role of socio-economic factors in influencing farmers’ adoption to soil conservation technologies in Bugoye Sub-county, Rwenzori Mountain. A cross sectional household survey design was used in this study, using systematic sampling to obtain 150 household samples. Qualitative analysis and chi-square tests were used to analyze these data. Results indicated that only 54% of the sampled households have adopted soil conservation, and revealed that eight of the nine factors significantly influenced farmers’ adoption, which are slope, farm size, farm distance from home, education level, family income, training, membership to NGOs, and credit accessibility. Only family size was insignificant. Other constraints are labour demands, cost of conservation work, land fragmentation, crop pests, and the limited agricultural extension services. It is recommended to perform training for farmers on designing soil conservation structures. Policies for empowering farmers with extra income are crucial to increase the adoption of soil conservation efforts.

  9. Available nitrogen is the key factor influencing soil microbial functional gene diversity in tropical rainforest.

    Science.gov (United States)

    Cong, Jing; Liu, Xueduan; Lu, Hui; Xu, Han; Li, Yide; Deng, Ye; Li, Diqiang; Zhang, Yuguang

    2015-08-20

    Tropical rainforests cover over 50% of all known plant and animal species and provide a variety of key resources and ecosystem services to humans, largely mediated by metabolic activities of soil microbial communities. A deep analysis of soil microbial communities and their roles in ecological processes would improve our understanding on biogeochemical elemental cycles. However, soil microbial functional gene diversity in tropical rainforests and causative factors remain unclear. GeoChip, contained almost all of the key functional genes related to biogeochemical cycles, could be used as a specific and sensitive tool for studying microbial gene diversity and metabolic potential. In this study, soil microbial functional gene diversity in tropical rainforest was analyzed by using GeoChip technology. Gene categories detected in the tropical rainforest soils were related to different biogeochemical processes, such as carbon (C), nitrogen (N) and phosphorus (P) cycling. The relative abundance of genes related to C and P cycling detected mostly derived from the cultured bacteria. C degradation gene categories for substrates ranging from labile C to recalcitrant C were all detected, and gene abundances involved in many recalcitrant C degradation gene categories were significantly (P rainforest. Soil available N could be the key factor in shaping the soil microbial functional gene structure and metabolic potential.

  10. Relationships between physical-geographical factors and soil degradation on agricultural land.

    Science.gov (United States)

    Bednář, Marek; Šarapatka, Bořivoj

    2018-07-01

    It is a well-known fact that soil degradation is dramatically increasing and currently threatens agricultural soils all around the world. The objective of this study was to reveal the possible connection between soil degradation and seven physical-geographical factors - slope steepness, altitude, elevation differences, rainfall, temperature, soil texture and solar radiation - in the form of threshold values (if these exist), where soil degradation begins and ends. The analysis involved the whole area of the Czech Republic which consists of 13,027 cadasters (78,866 km 2 ). The greatest total degradation threat occurs in areas with slope steepness >7 degrees, average annual temperature 10.54, altitude >766 m a.s.l. Similarly, the results for water erosion, wind erosion, soil compaction, loss of organic matter, acidification and heavy metal contamination were processed. The results enable us to identify the relationships of different levels of threats which could consequently be used in various ways - for classification of threatened areas, for more effective implementation of anti-degradation measures, or purely for a better understanding of the role of physical geographical factors in soil degradation in the Czech Republic, and thus could increase the chances of reducing vulnerability to land degradation not only in the Czech Republic. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Polycyclic aromatic hydrocarbons in soils from the Tibetan Plateau, China: distribution and influence of environmental factors.

    Science.gov (United States)

    Wang, Shuang; Ni, Hong-Gang; Sun, Jian-Lin; Jing, Xin; He, Jin-Sheng; Zeng, Hui

    2013-03-01

    Thirty four sampling sites along an elevation transect in the Tibetan Plateau region were chosen. Soil cores were divided into several layers and a total of 175 horizon soil samples were collected from July to September 2011, for determination of polycyclic aromatic hydrocarbons (PAHs). The measured PAHs concentration in surface soils was 56.26 ± 45.84 ng g(-1), and the low molecular weight PAHs (2-3 rings) predominated, accounting for 48% and 35%. We analyzed the spatial (altitudinal and vertical) distribution of PAHs in soil, and explored the influence of related environmental factors. Total organic carbon (TOC) showed a controlling influence on the distribution of PAHs. PAH concentrations declined with soil depth, and the composition patterns of PAHs along soil depth indicated that the heavy PAHs tended to remain in the upper layers (0-10 cm), while the light fractions were transported downward more easily. PAHs inventories (8.77-57.92 mg m(-2)) for soil cores increased with mean annual precipitation, while the topsoil concentrations decreased with it. This implies that an increase in precipitation could transfer more PAHs from the atmosphere to the soil and further transport PAHs from the topsoil to deeper layers.

  12. Nutrient Enrichment Mediates the Relationships of Soil Microbial Respiration with Climatic Factors in an Alpine Meadow

    Directory of Open Access Journals (Sweden)

    Ning Zong

    2015-01-01

    Full Text Available Quantifying the effects of nutrient additions on soil microbial respiration (Rm and its contribution to soil respiration (Rs are of great importance for accurate assessment ecosystem carbon (C flux. Nitrogen (N addition either alone (coded as LN and HN or in combination with phosphorus (P (coded as LN + P and HN + P were manipulated in a semiarid alpine meadow on the Tibetan Plateau since 2008. Either LN or HN did not affect Rm, while LN + P enhanced Rm during peak growing periods, but HN + P did not affect Rm. Nutrient addition also significantly affected Rm/Rs, and the correlations of Rm/Rs with climatic factors varied with years. Soil water content (Sw was the main factor controlling the variations of Rm/Rs. During the years with large rainfall variations, Rm/Rs was negatively correlated with Sw, while, in years with even rainfall, Rm/Rs was positively correlated with Sw. Meanwhile, in N + P treatments the controlling effects of climatic factors on Rm/Rs were more significant than those in CK. Our results indicate that the sensitivity of soil microbes to climatic factors is regulated by nutrient enrichment. The divergent effects of Sw on Rm/Rs suggest that precipitation distribution patterns are key factors controlling soil microbial activities and ecosystem C fluxes in semiarid alpine meadow ecosystems.

  13. Application of positive matrix factorization to identify potential sources of PAHs in soil of Dalian, China

    International Nuclear Information System (INIS)

    Wang Degao; Tian Fulin; Yang Meng; Liu Chenlin; Li Yifan

    2009-01-01

    Soil derived sources of polycyclic aromatic hydrocarbons (PAHs) in the region of Dalian, China were investigated using positive matrix factorization (PMF). Three factors were separated based on PMF for the statistical investigation of the datasets both in summer and winter. These factors were dominated by the pattern of single sources or groups of similar sources, showing seasonal and regional variations. The main sources of PAHs in Dalian soil in summer were the emissions from coal combustion average (46%), diesel engine (30%), and gasoline engine (24%). In winter, the main sources were the emissions from coal-fired boiler (72%), traffic average (20%), and gasoline engine (8%). These factors with strong seasonality indicated that coal combustion in winter and traffic exhaust in summer dominated the sources of PAHs in soil. These results suggested that PMF model was a proper approach to identify the sources of PAHs in soil. - PMF model is a proper approach to identify potential sources of PAHs in soil based on the PAH profiles measured in the field and those published in the literature.

  14. Fossil energy consumption and greenhouse gas emissions, including soil carbon effects, of producing agriculture and forestry feedstocks

    Science.gov (United States)

    Christina E. Canter; Zhangcai Qin; Hao Cai; Jennifer B. Dunn; Michael Wang; D. Andrew Scott

    2017-01-01

    The GHG emissions and fossil energy consumption associated with producing potential biomass sup­ply in the select BT16 scenarios include emissions and energy consumption from biomass production, harvest/collection, transport, and pre-processing activities to the reactor throat. Emissions associated with energy, fertilizers, and...

  15. Soil chemical factors and grassland species density in Emas National Park (central Brazil).

    Science.gov (United States)

    Amorim, P K; Batalha, M A

    2008-05-01

    Studies of grasslands on specific soil types suggest that different nutrients can limit biomass production and, hence, species composition and number. The Brazilian cerrado is the major savanna region in America and once covered about 2 million km(2), mainly in the Brazilian Central Plateau, under seasonal climate, with wet summer and dry winter. In view of the importance of soil chemical factors in the distribution of the vegetation forms within the Cerrado domain and which may influence the number of species, we analyzed some soil characteristics in three herbaceous vegetation forms -- hyperseasonal cerrado, seasonal cerrado, and wet grassland -- in Emas National Park, a core cerrado site, to investigate the relationship between number of species and soil characteristics. We collected vegetation and soil samples in these three vegetation forms and submitted the obtained data to multiple linear regression. We found out that aluminum and pH were the best predictors of species density, the former positively related to species density and the latter negatively related. Since the predictable variation in species density is important in determining areas of conservation, we can postulate that these two soil factors are indicators of high species density areas in tropical grasslands, which could be used in selecting priority sites for conservation.

  16. Factor value determination and applicability evaluation of universal soil loss equation in granite gneiss region

    Directory of Open Access Journals (Sweden)

    Wen-hai Zhang

    2009-06-01

    Full Text Available Six types of runoff plots were set up and an experimental study was carried out to examine natural rate of soil and water loss in the granite gneiss region of northern Jiangsu Province in China. Through correlation analysis of runoff and soil loss during 364 rainfall events, a simplified and convenient mathematical formula suitable for calculating the rainfall erosivity factor (R for the local region was established. Other factors of the universal soil loss equation (USLE model were also determined. Relative error analysis of the soil loss of various plots calculated by the USLE model on the basis of the observed values showed that the relative error ranged from -3.5% to 9.9% and the confidence level was more than 90%. In addition, the relative error was 5.64% for the terraced field and 12.36% for the sloping field in the practical application. Thus, the confidence level was above 87.64%. These results provide a scientific basis for forecasting and monitoring soil and water loss, for comprehensive management of small watersheds, and for soil and water conservation planning in the region.

  17. Soil geochemical factors regulate Cd accumulation by metal hyperaccumulating Noccaea caerulescens (J. Presl & C. Presl) F.K. Mey in field-contaminated soils.

    Science.gov (United States)

    Rosenfeld, Carla E; Chaney, Rufus L; Martínez, Carmen E

    2018-03-01

    Cadmium contamination in soil is a substantial global problem, and of significant concern due to high food-chain transfer. Cadmium hyperaccumulators are of particular interest because of their ability to tolerate and take up significant amounts of heavy metal pollution from soils. One particular plant, Noccaea caerulescens (formerly, Thlaspi caerulescens), has been extensively studied in terms of its capacity to accumulate heavy metals (specifically Zn and Cd), though these studies have primarily utilized hydroponic and metal-spiked model soil systems. We studied Cd and nutrient uptake by two N. caerulescens ecotypes, Prayon (Zn-only hyperaccumulator) and Ganges (Zn- and Cd-hyperaccumulator) in four long-term field-contaminated soils. Our data suggest that individual soil properties such as total soil Cd, Zn:Cd molar ratio, or soil pH do not accurately predict Cd uptake by hyperaccumulating plants. Additionally, total Cd uptake by the hyperaccumulating Ganges ecotype was substantially less than its physiological capacity, which is likely due to Cd-containing solid phases (primarily iron oxides) and pH that play an important role in regulating and limiting Cd solubility. Increased P accumulation in the Ganges leaves, and greater plant Fe accumulation from Cd-containing soils suggests that rhizosphere alterations via proton, and potentially organic acid, secretion may also play a role in nutrient and Cd acquisition by the plant roots. The current study highlights the role that soil geochemical factors play in influencing Cd uptake by hyperaccumulating plants. While these plants may have high physiological potential to accumulate metals from contaminated soils, individual soil geochemical factors and the plant-soil interactions in that soil will dictate the actual amount of phytoextractable metal. This underlines the need for site-specific understanding of metal-containing solid phases and geochemical properties of soils before undertaking phytoextraction efforts

  18. Soil variability in mountain areas

    OpenAIRE

    Zanini, E.; Freppaz, M.; Stanchi, S.; Bonifacio, E.; Egli, M.

    2015-01-01

    The high spatial variability of soils is a relevant issue at local and global scales, and determines the complexity of soil ecosystem functions and services. This variability derives from strong dependencies of soil ecosystems on parent materials, climate, relief and biosphere, including human impact. Although present in all environments, the interactions of soils with these forming factors are particularly striking in mountain areas.

  19. Soil-to-crop transfer factors of radium in Japanese agricultural fields

    International Nuclear Information System (INIS)

    Uchida, S.; Tagami, K.

    2007-01-01

    The concentrations of 226 Ra in upland field crops (e.g., cabbage, leek, onion, potato, and so on) and associated soils collected from 45 locations throughout Japan were determined in order to obtain soil-to-crop transfer factors (TFs). Concentrations of 226 Ra in the soils collected in southwestern Japan were higher than those in northeastern Japan; however, no correlations between 226 Ra concentrations in crops and soils were observed. The TFs ranged from -3 to 5.8 x 10 -2 with a geometric mean of 6.4 x 10 -3 . These data were within the 95% confidential range of TF-Ra for several crops as reported in the IAEA Technical Reports Series No.364. Among the alkaline earth metals. TF-Ba was similar to TF-Ra. (author)

  20. Transfer factors of radionuclides 137Cs and 65Zn from soil to pearl millet and sorghum

    International Nuclear Information System (INIS)

    Sachdev, P.; Sachdev, M.S.; Deb, D.L.

    1996-01-01

    The soil to plant transfer factors (TF) of 137 Cs and 65 Zn were determined for two crops, sorghum and pearl millet, under irrigated conditions in greenhouse and under rain fed conditions in field. In the greenhouse experiment, the accumulation of 137 Cs was almost doubled when the soil contamination level was doubled. Under field conditions, 137 Cs concentration in both pearl millet and sorghum grains as well as straw was nearly four times more at 148 kBq Kg -1 level of soil contamination as compared to lower level of 74 kBq kg -1 soil. The TF values for 65 Zn determined under greenhouse conditions for both the crops were nearly a hundred-fold higher as compared to 137 Cs. (author). 7 refs., 2 tabs

  1. [Dynamic changes in soil respiration components and their regulating factors in the Moso bamboo plantation in subtropical China].

    Science.gov (United States)

    Yang, Wen-jia; Li, Yong-fu; Jiang, Pei-kun; Zhou, Guo-mo; Liu, Juan

    2015-10-01

    Dynamic changes (from April 2013 to March 2014) in soil respiration components were investigated by Li-8100 in the Moso bamboo plantation in Lin' an City, Zhejiang Province. Results showed that the average annual values for the soil total respiration rate, heterotrophic respiration rate, and autotrophic respiration rate in the Moso bamboo plantation were 2.93, 1.92 and 1.01 imol CO2 . m-2 . s-1, respectively. The soil respiration rate and its components exhibited strongly a seasonal dynamic pattern. The maximum appeared in July 2013, and the minimum appeared in January 2014. The annual cumulative CO2 emissions through soil respiration, heterotrophic respiration, and autotrophic respiration were 37.25, 24.61 and 12.64 t CO2 . hm-2 . a-1, respectively. The soil respiration and its components showed a close relation with soil temperature of 5 cm depth, and the corresponding Q10, values at 5 cm depth were 2.05, 1.95 and 2.34, respectively. Both the soil respiration and heterotrophic respiration were correlated to soil water soluble organic C (WSOC) content, but no significant relationship between autotrophic respiration and WSOC was observed. There were no significant relationships between soil respiration components and soil moisture content or microbial biomass C. The seasonal changes in soil respiration components in the Moso bamboo plantation were predominantly controlled by the soil temperature, and the soil WSOC content was an important environmental factor controlling total soil respiration and soil heterotrophic respiration.

  2. [Relation between species distribution of plant community and soil factors under grazing in alpine meadow].

    Science.gov (United States)

    Niu, Yu Jie; Yang, Si Wei; Wang, Gui Zhen; Liu, Li; Du, Guo Zhen; Hua, Li Min

    2017-12-01

    The research selected the alpine meadow located in the northeastern margin of the Qinghai-Tibet Plateau to study the changes of vegetation community and soil properties under different grazing intensities, as well as the quantitative relation between the distribution patterns of plant species and the physical and chemical properties of soil. The results showed that the grazing caused the differentiation of the initial vegetation community with the dominant plants, Elymus nutans and Stipa grandis. In the plots with high and low grazing intensities, the dominant plants had changed to Kobresia humilis and Melissitus ruthenica, and E. nutans and Poa crymophila, respectively. With the increase of grazing intensity, the plant richness, importance value and biomass were significantly decreased. The sequence of plant species importance value in each plot against grazing intensity could be fitted by a logarithmic model. The number of required plant species was reduced while the importance value of the remaining plant species accounted for 50% of the importance value in the whole vegetation community. The available P, available K, soil compaction, soil water content, stable infiltration rate and large aggregate index were significantly changed with grazing intensity, however, the changes were different. The CCA ordination showed that the soil compaction was the key factor affecting the distribution pattern of the plant species under grazing. The variance decomposition indicated that the soil factors together explained 30.5% of the distribution of the plant species, in particular the soil physical properties alone explained 22.8% of the distribution of the plant species, which had the highest rate of contribution to the plant species distribution. The soil physical properties affected the distribution pattern of plant species on grazed alpine meadow.

  3. Relationship between soil chemical factors and grassland diversity

    NARCIS (Netherlands)

    Janssens, F; Peeters, A; Tallowin, JRB; Bakker, JP; Bekker, RM; Fillat, F; Oomes, MJM

    Many studies carried out during these last few years have focused on the factors influencing plant diversity in species-rich grasslands. This is due to the fact that these ecosystems, among the most diversified in temperate climates, are extremely threatened; in some areas, they have almost

  4. Hot regions of labile and stable soil organic carbon in Germany - Spatial variability and driving factors

    Science.gov (United States)

    Vos, Cora; Jaconi, Angélica; Jacobs, Anna; Don, Axel

    2018-06-01

    Atmospheric carbon dioxide levels can be mitigated by sequestering carbon in the soil. Sequestration can be facilitated by agricultural management, but its influence is not the same on all soil carbon pools, as labile pools with a high turnover may be accumulated much faster but are also more vulnerable to losses. The aims of this study were to (1) assess how soil organic carbon (SOC) is distributed among SOC fractions on a national scale in Germany, (2) identify factors influencing this distribution and (3) identify regions with high vulnerability to SOC losses. The SOC content and proportion of two different SOC fractions were estimated for more than 2500 mineral topsoils (soil texture, bulk soil C / N ratio, total SOC content and pH. For some regions, the drivers were linked to the land-use history of the sites. Arable topsoils in central and southern Germany were found to contain the highest proportions and contents of stable SOC fractions, and therefore have the lowest vulnerability to SOC losses. North-western Germany contains an area of sandy soils with unusually high SOC contents and high proportions of light SOC fractions, which are commonly regarded as representing a labile carbon pool. This is true for the former peat soils in this area, which have already lost and are at high risk of losing high proportions of their SOC stocks. Those black sands can, however, also contain high amounts of stable SOC due to former heathland vegetation and need to be treated and discussed separately from non-black sand agricultural soils. Overall, it was estimated that, in large areas all over Germany, over 30 % of SOC is stored in easily mineralisable forms. Thus, SOC-conserving management of arable soils in these regions is of great importance.

  5. GEOSTATISTICAL BASED SUSCEPTIBILITY MAPPING OF SOIL EROSION AND OPTIMIZATION OF ITS CAUSATIVE FACTORS: A CONCEPTUAL FRAMEWORK

    Directory of Open Access Journals (Sweden)

    ABDULKADIR T. SHOLAGBERU

    2017-11-01

    Full Text Available Soil erosion hazard is the second biggest environmental challenges after population growth causing land degradation, desertification and water deterioration. Its impacts on watersheds include loss of soil nutrients, reduced reservoir capacity through siltation which may lead to flood risk, landslide, high water turbidity, etc. These problems become more pronounced in human altered mountainous areas through intensive agricultural activities, deforestation and increased urbanization among others. However, due to challenging nature of soil erosion management, there is great interest in assessing its spatial distribution and susceptibility levels. This study is thus intend to review the recent literatures and develop a novel framework for soil erosion susceptibility mapping using geostatistical based support vector machine (SVM, remote sensing and GIS techniques. The conceptual framework is to bridge the identified knowledge gaps in the area of causative factors’ (CFs selection. In this research, RUSLE model, field studies and the existing soil erosion maps for the study area will be integrated for the development of inventory map. Spatial data such as Landsat 8, digital soil and geological maps, digital elevation model and hydrological data shall be processed for the extraction of erosion CFs. GISbased SVM techniques will be adopted for the establishment of spatial relationships between soil erosion and its CFs, and subsequently for the development of erosion susceptibility maps. The results of this study include evaluation of predictive capability of GIS-based SVM in soil erosion mapping and identification of the most influential CFs for erosion susceptibility assessment. This study will serve as a guide to watershed planners and to alleviate soil erosion challenges and its related hazards.

  6. Use of the neutron activation technique: soil-plant transfer factor

    International Nuclear Information System (INIS)

    Silva, Wellington Ferrari da; Menezes, Maria Ângela de B.C.; Marques, Douglas José

    2017-01-01

    Recent studies have demonstrated the importance of the soil-plant transfer factor in the absorption and translocation of chemical elements, thus, it is possible to evaluate a better decision-making in the consecutive plantations. To determine these values, the content of a chemical element present in the plant or part of it with the total content present in the same soil where it is grown is considered. The objective of this study was to determine the concentrations of the chemical elements present in soil, leaf and grains corn, by neutron activation analysis and to compare the different soil-plant transfer factors. The samples were collected in a property located in the region of Biquinhas, MG, and irradiated in the TRIGA MARK I IPR-R1 CDTN / CNEN nuclear reactor. Thus, the concentrations of Br, Ce Fe, K, La, Na, Rb, Zn were determined. The soil-plant transfer factors for the elements found were varied, indicating a greater potassium absorption capacity (K). (author)

  7. Use of the neutron activation technique: soil-plant transfer factor

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Wellington Ferrari da, E-mail: wferrari250@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pós-Graduação em Ciências e Técnicas Nucleares; Menezes, Maria Ângela de B.C., E-mail: menezes@cdtn.br [Centro Desenvolvimento da Tecnologia Nuclear (SERTA/CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Serviço de Técnicas Analíticas. Laboratório de Ativação Neutrônica; Marques, Douglas José, E-mail: douglasjmarques81@yahoo.com.br [Universidade José do Rosário Vellano, Alfenas, MG (Brazil). Setor de Olericultura e Experimentação em Agricultura Orgânica

    2017-07-01

    Recent studies have demonstrated the importance of the soil-plant transfer factor in the absorption and translocation of chemical elements, thus, it is possible to evaluate a better decision-making in the consecutive plantations. To determine these values, the content of a chemical element present in the plant or part of it with the total content present in the same soil where it is grown is considered. The objective of this study was to determine the concentrations of the chemical elements present in soil, leaf and grains corn, by neutron activation analysis and to compare the different soil-plant transfer factors. The samples were collected in a property located in the region of Biquinhas, MG, and irradiated in the TRIGA MARK I IPR-R1 CDTN / CNEN nuclear reactor. Thus, the concentrations of Br, Ce Fe, K, La, Na, Rb, Zn were determined. The soil-plant transfer factors for the elements found were varied, indicating a greater potassium absorption capacity (K). (author)

  8. Concentration and measuring Platinum Group Elements (PGE) Transfer Factor in soil and vegetations

    International Nuclear Information System (INIS)

    Adibah Sakinah Oyub

    2012-01-01

    This study was conducted to determine the concentration and to measure platinum group elements (PGE) transfer factor in environmental samples of roadside soil and vegetation. The use of vehicle catalytic converter has released platinum group elements (PGE) and other gases into the environment. Thus, roadside soil and plants were exposed to this element and has become the medium for the movement of this elements. Samples of roadside soil and vegetation were taken at various locations in UKM Bangi Toll and the concentration of platinum group elements (PGE) is determined using mass spectrometry-inductively coupled plasma (ICP-MS). Overall, the concentrations of platinum group elements (PGE), which is the element platinum (Pt) in soil was 0.016 ± 0.036 μgg -1 . While the concentration of the elements palladium (Pd) was 0.079 ± 0.019 μgg -1 and element rhodium (Rh) is at a concentration of 0.013 ± 0.020 μgg -1 . Overall, the transfer factor for the element platinum (Pt) is 1. While the transfer factor of the element palladium (Pd) is 0.96 and the element rhodium (Rh) is 1.11. In conclusion, the concentration of platinum group elements (PGE) in soils have increased. (author)

  9. Improving and disaggregating N_2O emission factors for ruminant excreta on temperate pasture soils

    International Nuclear Information System (INIS)

    Krol, D.J.; Carolan, R.; Minet, E.; McGeough, K.L.; Watson, C.J.; Forrestal, P.J.; Lanigan, G.J.; Richards, K.G.

    2016-01-01

    Cattle excreta deposited on grazed grasslands are a major source of the greenhouse gas (GHG) nitrous oxide (N_2O). Currently, many countries use the IPCC default emission factor (EF) of 2% to estimate excreta-derived N_2O emissions. However, emissions can vary greatly depending on the type of excreta (dung or urine), soil type and timing of application. Therefore three experiments were conducted to quantify excreta-derived N_2O emissions and their associated EFs, and to assess the effect of soil type, season of application and type of excreta on the magnitude of losses. Cattle dung, urine and artificial urine treatments were applied in spring, summer and autumn to three temperate grassland sites with varying soil and weather conditions. Nitrous oxide emissions were measured from the three experiments over 12 months to generate annual N_2O emission factors. The EFs from urine treated soil was greater (0.30–4.81% for real urine and 0.13–3.82% for synthetic urine) when compared with dung (− 0.02–1.48%) treatments. Nitrous oxide emissions were driven by environmental conditions and could be predicted by rainfall and temperature before, and soil moisture deficit after application; highlighting the potential for a decision support tool to reduce N_2O emissions by modifying grazing management based on these parameters. Emission factors varied seasonally with the highest EFs in autumn and were also dependent on soil type, with the lowest EFs observed from well-drained and the highest from imperfectly drained soil. The EFs averaged 0.31 and 1.18% for cattle dung and urine, respectively, both of which were considerably lower than the IPCC default value of 2%. These results support both lowering and disaggregating EFs by excreta type. - Highlights: • N_2O emissions were measured from cattle excreta applied to pasture. • N_2O was universally higher from urine compared with dung. • N_2O was driven by rainfall, temperature and soil moisture deficit. • Emission

  10. Influence of multiple factors on plant local adaptation: soil type and folivore effects in Ruellia nudiflora (Acanthaceae)

    OpenAIRE

    Ortegón-Campos, I.; Abdala-Roberts, Luis; Parra-Tabla, Víctor; Cervera, J. Carlos; Marrufo-Zapata, Denis; Herrera, Carlos M.

    2011-01-01

    Different environmental factors can have contrasting effects on the extent of plant local adaptation (LA). Here we evaluate the influence of folivory and soil type on LA in Ruellia nudiflora by performing reciprocal transplants at two sites in Yucatan (Mexico) while controlling for soil source and folivory level. Soil samples were collected at each site and half of the plants of each source at each site were grown with one soil source and half with the other. After transplanting, we reduced f...

  11. Discriminating impacts of geomorphological and human factors on vineyard soil erosion (Burgundy, France)

    Science.gov (United States)

    Chevigny, Emmanuel; Quiquerez, Amélie; Petit, Christophe; Curmi, Pierre

    2014-05-01

    The Burgundy vineyards have been recognized for the high diversity of Terroirs, controlled by complex interactions between natural features, historical parameters and soil management practices. Vineyards are known to undergo substantial soil loss in comparison with other types of agricultural land. Hydric erosion on vineyards is controlled by complex interactions of natural and anthropogenic factors leading to intra-plot spatial heterogeneities of topsoil at a scale of a metre. Studying the relationship between soils and their degradation is crucial in this situation where soil sustainability is threatened. This study explores the relative influences of historical and present-day anthropogenic factors and geomorphological processes controlling soil erosion on vineyard hillslopes. The selected area was located in the Monthelie vineyard (Côte de Beaune, France) where intensive erosion occurred during high-intensity rainfall events. Soil erosion quantification was performed at a square-metre scale using dendrogeomorphology. This method is based on the measurement of the unearthing of the stock located on the vine plants, considered as a passive marker of soil-surface vertical displacement since the year of plantation. The obtained maps, together with various complementary datasets, such as geological and geomorphological data, but also historical documents (cadastral plans, cadastral matrices and old aerial photographs) allow landscape evolution to be assessed. The combination of all these data shows that spatial distribution and intensity of erosion are controlled mainly by lithology and slope value. However, our study highlights that the sediment dynamics in this vineyard plot is highly related to historical former plot limits and present-day management practices. Nonetheless, quantification of sediment dynamic for the last decade reveals that the impacts of historical structures are disappearing gradually, in response to present-day management practices and

  12. The Benefits of Including Clinical Factors in Rectal Normal Tissue Complication Probability Modeling After Radiotherapy for Prostate Cancer

    International Nuclear Information System (INIS)

    Defraene, Gilles; Van den Bergh, Laura; Al-Mamgani, Abrahim; Haustermans, Karin; Heemsbergen, Wilma; Van den Heuvel, Frank; Lebesque, Joos V.

    2012-01-01

    Purpose: To study the impact of clinical predisposing factors on rectal normal tissue complication probability modeling using the updated results of the Dutch prostate dose-escalation trial. Methods and Materials: Toxicity data of 512 patients (conformally treated to 68 Gy [n = 284] and 78 Gy [n = 228]) with complete follow-up at 3 years after radiotherapy were studied. Scored end points were rectal bleeding, high stool frequency, and fecal incontinence. Two traditional dose-based models (Lyman-Kutcher-Burman (LKB) and Relative Seriality (RS) and a logistic model were fitted using a maximum likelihood approach. Furthermore, these model fits were improved by including the most significant clinical factors. The area under the receiver operating characteristic curve (AUC) was used to compare the discriminating ability of all fits. Results: Including clinical factors significantly increased the predictive power of the models for all end points. In the optimal LKB, RS, and logistic models for rectal bleeding and fecal incontinence, the first significant (p = 0.011–0.013) clinical factor was “previous abdominal surgery.” As second significant (p = 0.012–0.016) factor, “cardiac history” was included in all three rectal bleeding fits, whereas including “diabetes” was significant (p = 0.039–0.048) in fecal incontinence modeling but only in the LKB and logistic models. High stool frequency fits only benefitted significantly (p = 0.003–0.006) from the inclusion of the baseline toxicity score. For all models rectal bleeding fits had the highest AUC (0.77) where it was 0.63 and 0.68 for high stool frequency and fecal incontinence, respectively. LKB and logistic model fits resulted in similar values for the volume parameter. The steepness parameter was somewhat higher in the logistic model, also resulting in a slightly lower D 50 . Anal wall DVHs were used for fecal incontinence, whereas anorectal wall dose best described the other two endpoints. Conclusions

  13. The Benefits of Including Clinical Factors in Rectal Normal Tissue Complication Probability Modeling After Radiotherapy for Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Defraene, Gilles, E-mail: gilles.defraene@uzleuven.be [Radiation Oncology Department, University Hospitals Leuven, Leuven (Belgium); Van den Bergh, Laura [Radiation Oncology Department, University Hospitals Leuven, Leuven (Belgium); Al-Mamgani, Abrahim [Department of Radiation Oncology, Erasmus Medical Center - Daniel den Hoed Cancer Center, Rotterdam (Netherlands); Haustermans, Karin [Radiation Oncology Department, University Hospitals Leuven, Leuven (Belgium); Heemsbergen, Wilma [Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Van den Heuvel, Frank [Radiation Oncology Department, University Hospitals Leuven, Leuven (Belgium); Lebesque, Joos V. [Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)

    2012-03-01

    Purpose: To study the impact of clinical predisposing factors on rectal normal tissue complication probability modeling using the updated results of the Dutch prostate dose-escalation trial. Methods and Materials: Toxicity data of 512 patients (conformally treated to 68 Gy [n = 284] and 78 Gy [n = 228]) with complete follow-up at 3 years after radiotherapy were studied. Scored end points were rectal bleeding, high stool frequency, and fecal incontinence. Two traditional dose-based models (Lyman-Kutcher-Burman (LKB) and Relative Seriality (RS) and a logistic model were fitted using a maximum likelihood approach. Furthermore, these model fits were improved by including the most significant clinical factors. The area under the receiver operating characteristic curve (AUC) was used to compare the discriminating ability of all fits. Results: Including clinical factors significantly increased the predictive power of the models for all end points. In the optimal LKB, RS, and logistic models for rectal bleeding and fecal incontinence, the first significant (p = 0.011-0.013) clinical factor was 'previous abdominal surgery.' As second significant (p = 0.012-0.016) factor, 'cardiac history' was included in all three rectal bleeding fits, whereas including 'diabetes' was significant (p = 0.039-0.048) in fecal incontinence modeling but only in the LKB and logistic models. High stool frequency fits only benefitted significantly (p = 0.003-0.006) from the inclusion of the baseline toxicity score. For all models rectal bleeding fits had the highest AUC (0.77) where it was 0.63 and 0.68 for high stool frequency and fecal incontinence, respectively. LKB and logistic model fits resulted in similar values for the volume parameter. The steepness parameter was somewhat higher in the logistic model, also resulting in a slightly lower D{sub 50}. Anal wall DVHs were used for fecal incontinence, whereas anorectal wall dose best described the other two endpoints

  14. Impact of abiotic factors on development of the community of arbuscular mycorrhizal fungi in the soil: a Review

    Science.gov (United States)

    Jamiołkowska, Agnieszka; Księżniak, Andrzej; Gałązka, Anna; Hetman, Beata; Kopacki, Marek; Skwaryło-Bednarz, Barbara

    2018-01-01

    Arbuscular mycorrhizal fungi inhabiting soil play an important role for vascular plants. Interaction between arbuscular mycorrhizal fungi, plants and soil microorganisms leads to many mutual advantages. However, the effectiveness of mycorrhizal fungi depends not only on biotic, but also abiotic factors such as physico-chemical properties of the soil, availability of water and biogenic elements, agricultural practices, and climatic conditions. First of all, it is important to adapt the arbuscular mycorrhizal fungi species to changing environmental conditions. The compactness of the soil and its structure have a huge impact on its biological activity. Soil pH reaction has a substantial impact on the mobility of ions in soil dilutions and their uptake by plants and soil microflora. Water excess can be a factor negatively affecting arbuscular mycorrhizal fungi because these microorganisms are sensitive to a lower availability of oxygen. Mechanical cultivation of the soil has a marginal impact on the arbuscular mycorrhizal fungi spores. However, soil translocation can cause changes to the population of the arbuscular mycorrhizal fungi abundance in the soil profile. The geographical location and topographic differentiation of cultivated soils, as well as the variability of climatic factors affect the population of the arbuscular mycorrhizal fungi in the soils and their symbiotic activity.

  15. Soil parameters are key factors to predict metal bioavailability to snails based on chemical extractant data

    International Nuclear Information System (INIS)

    Pauget, B.; Gimbert, F.; Scheifler, R.; Coeurdassier, M.; Vaufleury, A. de

    2012-01-01

    Although soil characteristics modulate metal mobility and bioavailability to organisms, they are often ignored in the risk assessment of metal transfer. This paper aims to determine the ability of chemical methods to assess and predict cadmium (Cd), lead (Pb) and zinc (Zn) environmental bioavailability to the land snail Cantareus aspersus. Snails were exposed in the laboratory for 28 days to 17 soils from around a former smelter. The soils were selected for their range of pH, organic matter, clay content, and Cd, Pb and Zn concentrations. The influence of soil properties on environmental availability (estimated using HF-HClO 4 , EDTA, CaCl 2 , NH 4 NO 3 , NaNO 3 , free ion activity and total dissolved metal concentration in soil solution) and on environmental bioavailability (modelled using accumulation kinetics) was identified. Among the seven chemical methods, only the EDTA and the total soil concentration can be used to assess Cd and Pb environmental bioavailability to snails (r² adj = 0.67 and 0.77, respectively). For Zn, none of the chemical methods were suitable. Taking into account the influence of the soil characteristics (pH and CEC) allows a better prediction of Cd and Pb environmental bioavailability (r² adj = 0.82 and 0.83, respectively). Even though alone none of the chemical methods tested could assess Zn environmental bioavailability to snails, the addition of pH, iron and aluminium oxides allowed the variation of assimilation fluxes to be predicted. A conceptual and practical method to use soil characteristics for risk assessment is proposed based on these results. We conclude that as yet there is no universal chemical method to predict metal environmental bioavailability to snails, and that the soil factors having the greatest impact depend on the metal considered. - Highlights: ► New approach to identify chemical methods able to predict metal bioavailability to snails. ► Bioavailability of cadmium, lead and zinc to snails was determined by

  16. Soil parameters are key factors to predict metal bioavailability to snails based on chemical extractant data

    Energy Technology Data Exchange (ETDEWEB)

    Pauget, B.; Gimbert, F., E-mail: frederic.gimbert@univ-fcomte.fr; Scheifler, R.; Coeurdassier, M.; Vaufleury, A. de

    2012-08-01

    Although soil characteristics modulate metal mobility and bioavailability to organisms, they are often ignored in the risk assessment of metal transfer. This paper aims to determine the ability of chemical methods to assess and predict cadmium (Cd), lead (Pb) and zinc (Zn) environmental bioavailability to the land snail Cantareus aspersus. Snails were exposed in the laboratory for 28 days to 17 soils from around a former smelter. The soils were selected for their range of pH, organic matter, clay content, and Cd, Pb and Zn concentrations. The influence of soil properties on environmental availability (estimated using HF-HClO{sub 4}, EDTA, CaCl{sub 2}, NH{sub 4}NO{sub 3}, NaNO{sub 3}, free ion activity and total dissolved metal concentration in soil solution) and on environmental bioavailability (modelled using accumulation kinetics) was identified. Among the seven chemical methods, only the EDTA and the total soil concentration can be used to assess Cd and Pb environmental bioavailability to snails (r Superscript-Two {sub adj} = 0.67 and 0.77, respectively). For Zn, none of the chemical methods were suitable. Taking into account the influence of the soil characteristics (pH and CEC) allows a better prediction of Cd and Pb environmental bioavailability (r Superscript-Two {sub adj} = 0.82 and 0.83, respectively). Even though alone none of the chemical methods tested could assess Zn environmental bioavailability to snails, the addition of pH, iron and aluminium oxides allowed the variation of assimilation fluxes to be predicted. A conceptual and practical method to use soil characteristics for risk assessment is proposed based on these results. We conclude that as yet there is no universal chemical method to predict metal environmental bioavailability to snails, and that the soil factors having the greatest impact depend on the metal considered. - Highlights: Black-Right-Pointing-Pointer New approach to identify chemical methods able to predict metal bioavailability

  17. [Seasonal variation of soil heat conduction in a larch plantation and its relations to environmental factors].

    Science.gov (United States)

    Wang, Wen-Jie; Cui, Song; Liu, Wei; Zu, Yuan-Gang; Sun, Wei; Wang, Hui-Min

    2008-10-01

    Based on a 3-year (2003-2005) observation of soil heat flux (SHF) in a larch (Larix gmelinii) plantation, the characteristics of soil heat conduction in the plantation and their relationships with environment factors were analyzed. The results showed that there was an obvious seasonal variation of SHF in different years and sampling sites. The SHF was positive from April to August and mostly negative from September to next March, with an almost balance between heat income and outcome at annual scale. Solar net radiation had significant effects on the SHF and soil heat conductance (k), and an obvious time-lag effect was found, with 4-5 hours' time-lag in winter and 2-3 hours' time-lag in summer. Based on the real-time measurement of SHF and soil temperature difference at the study sites, the k value was significantly higher in early spring (P 0.05). Therefore, when we use the observation data of soil temperature from weather stations to estimate soil heat flux, the k value in spring (from March to May) could induce a bias estimation.

  18. Soil-to-Plant Transfer Factors of {sup 99}Tc for Korean Major Upland Crops

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Ho; Lim, Kwang Muk; Jun, In; Keum, Dong Kwon [Korea Atomic Energy Reserach Institute, Daejeon (Korea, Republic of)

    2011-12-15

    In order to investigate the soil-to-plant transfer factor (TF) of {sup 99}Tc for Korean major upland crops (soybean, radish and Chinese cabbage), pot experiments were performed in a greenhouse. Soils were collected from four upland fields (two for soybean and two for radish and Chinese cabbage) around Gyeongju radioactive-waste disposal site. Three to four weeks before sowing, dried soils were mixed with a {sup 99}Tc solution and the mixtures were put into pots and irrigated. TF values were expressed as the ratios of the {sup 99}Tc concentrations in plants (Bq kg{sup -1}-dry or fresh) to those in soils (Bq kg{sup -1}-dry). There was no great difference in the TF value between soils. The TF values for soybean seeds were extremely lower than those for the straws, indicating a very low mobility of {sup 99}Tc to seeds. As representative TF values of{sup 99}Tc,1.8 X 10{sup -1}, 1.2 X 10{sup 1}, 3.2 X 10{sup 2} and 1.3 X 10{sup 2} (for dry plants), arithmetic means for two soils, were proposed for soybean seeds, radish roots, radish leaves and Chinese cabbage leaves, respectively. In the case of the vegetables, proposals for fresh plants were also made. The proposed values are not sufficiently representative so successive updates are needed.

  19. Geologic and edaphic factors influencing susceptibility of forest soils to environmental change

    Science.gov (United States)

    Scott W. Bailey

    2000-01-01

    There is great diversity in the structure and function of the northern forest across the 20-state portion of the United States considered in this book. The interplay of many factors accounts for the mosaic of ecological regimes across the region. In particular, climate, physiography, geology, and soils influence dominance and distribution of vegetation communities...

  20. Magnetic and chemical parameters of andic soils and their relation to selected pedogenesis factors

    Czech Academy of Sciences Publication Activity Database

    Grison, Hana; Petrovský, Eduard; Kapička, Aleš; Stejskalová, Šárka

    2016-01-01

    Roč. 139, April (2016), s. 179-190 ISSN 0341-8162 R&D Projects: GA ČR GA13-10775S Institutional support: RVO:67985530 Keywords : andosols * magnetic susceptibility * basalts * iron oxides * frequency-dependent susceptibility Subject RIV: DF - Soil Science Impact factor: 3.191, year: 2016

  1. Soil moisture and biogeochemical factors influence the distribution of annual Bromus species

    Science.gov (United States)

    Jayne Belnap; John M. Stark; Benjamin M. Rau; Edith B. Allen; Susan Phillips

    2016-01-01

    Abiotic factors have a strong influence on where annual Bromus species are found. At the large regional scale, temperature and precipitation extremes determine the boundaries of Bromus occurrence. At the more local scale, soil characteristics and climate influence distribution, cover, and performance. In hot, dry, summer-rainfall-dominated deserts (Sonoran, Chihuahuan...

  2. Estimation of N2O emission factors for soils depending on environmental conditions and crop management

    NARCIS (Netherlands)

    Lesschen, J.P.; Velthof, G.L.

    2009-01-01

    Nitrous oxide (N2O) contributes 8% to anthropogenic global warming, of which about one third are direct emissions of agricultural soils. These N2O emissions are often estimated using the default IPCC 2006 emission factor of 1% of the amount of N applied for mineral fertilizer, manure and crop

  3. Traffic-related trace elements in soils along six highway segments on the Tibetan Plateau: Influence factors and spatial variation.

    Science.gov (United States)

    Wang, Guanxing; Zeng, Chen; Zhang, Fan; Zhang, Yili; Scott, Christopher A; Yan, Xuedong

    2017-03-01

    The accumulation of traffic-related trace elements in soil as the result of anthropogenic activities raises serious concerns about environmental pollution and public health. Traffic is the main source of trace elements in roadside soil on the Tibetan Plateau, an area otherwise devoid of industrial emissions. Indeed, the rapid development of tourism and transportation in this region means it is becoming increasingly important to identify the accumulation levels, influence distance, spatial distribution, and other relevant factors influencing trace elements. In this study, 229 soil samples along six segments of the major transportation routes on the Tibetan Plateau (highways G214, S308, and G109), were collected for analysis of eight trace elements (Cr, Co, Ni, As, Cu, Zn, Cd, and Pb). The results of statistical analyses showed that of the eight trace elements in soils, Cu, Zn, Cd, and Pb were primarily derived from traffic. The relationship between the trace element accumulation levels and the distance from the roadside followed an exponential decline, with the exception of Segment 3, the only unpaved gravel road studied. In addition, the distance of influence from the roadside varied by trace element and segment, ranging from 16m to 144m. Background values for each segment were different because of soil heterogeneity, while a number of other potential influencing factors (including traffic volume, road surface material, roadside distance, land cover, terrain, and altitude) all had significant effects on trace-element concentrations. Overall, however, concentrations along most of the road segments investigated were at, or below, levels defined as low on the Nemero Synthesis index. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Factors affecting cadmium absorbed by pistachio kernel in calcareous soils, southeast of Iran.

    Science.gov (United States)

    Shirani, H; Hosseinifard, S J; Hashemipour, H

    2018-03-01

    Cadmium (Cd) which does not have a biological role is one of the most toxic heavy metals for organisms. This metal enters environment through industrial processes and fertilizers. The main objective of this study was to determine the relationships between absorbed Cd by pistachio kernel and some of soil physical and chemical characteristics using modeling by stepwise regression and Artificial Neural Network (ANN), in calcareous soils in Rafsanjan region, southeast of Iran. For these purposes, 220 pistachio orchards were selected, and soil samples were taken from two depths of 0-40 and 40-80cm. Besides, fruit and leaf samples from branches with and without fruit were taken in each sampling point. The results showed that affecting factors on absorbed Cd by pistachio kernel which were obtained by regression method (pH and clay percent) were not interpretable, and considering unsuitable vales of determinant coefficient (R 2 ) and Root Mean Squares Error (RMSE), the model did not have sufficient validity. However, ANN modeling was highly accurate and reliable. Based on its results, soil available P and Zn and soil salinity were the most important factors affecting the concentration of Cd in pistachio kernel in pistachio growing areas of Rafsanjan. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Determination of factors associated with natural soil suppressivity to potato common scab.

    Directory of Open Access Journals (Sweden)

    Marketa Sagova-Mareckova

    Full Text Available Common scab of potatoes is a disease, which is difficult to manage due to complex interactions of the pathogenic bacteria (Streptomyces spp. with soil, microbial community and potato plants. In Bohemian-Moravian Highlands in the Czech Republic two sites (Vyklantice and Zdirec were selected for a study of common scab disease suppressivity. At both sites, a field with low disease severity occurs next to one with high severity and the situation was regularly observed over four decades although all four fields undergo a crop rotation. In the four fields, quantities of bacteria, actinobacteria and the gene txtB from the biosynthetic gene cluster of thaxtomin, the main pathogenicity factor of common scab, were analyzed by real-time PCR. Microbial community structure was compared by terminal fragment length polymorphism analysis. Soil and potato periderm were characterized by contents of carbon, nitrogen, phosphorus, sulphur, calcium, magnesium, and iron. Quality of organic matter was assessed by high performance liquid chromatography of soil extracts. The study demonstrated that the suppressive character of the fields is locally specific. At Zdirec, the suppressivity was associated with low txtB gene copies in bulk soil, while at Vyklantice site it was associated with low txtB gene copies in the tuberosphere. The differences were discussed with respect to the effect of abiotic conditions at Zdirec and interaction between potato plant and soil microbial community at Vyklantice. Soil pH, Ca soil content or cation concentrations, although different were not in the range to predict the disease severity. Low severity of common scab was associated with low content of soil C, N, C/N, Ca and Fe suggesting that oligotrophic conditions may be favorable to common scab suppression.

  6. Determination of factors associated with natural soil suppressivity to potato common scab.

    Science.gov (United States)

    Sagova-Mareckova, Marketa; Daniel, Ondrej; Omelka, Marek; Kristufek, Vaclav; Divis, Jiri; Kopecky, Jan

    2015-01-01

    Common scab of potatoes is a disease, which is difficult to manage due to complex interactions of the pathogenic bacteria (Streptomyces spp.) with soil, microbial community and potato plants. In Bohemian-Moravian Highlands in the Czech Republic two sites (Vyklantice and Zdirec) were selected for a study of common scab disease suppressivity. At both sites, a field with low disease severity occurs next to one with high severity and the situation was regularly observed over four decades although all four fields undergo a crop rotation. In the four fields, quantities of bacteria, actinobacteria and the gene txtB from the biosynthetic gene cluster of thaxtomin, the main pathogenicity factor of common scab, were analyzed by real-time PCR. Microbial community structure was compared by terminal fragment length polymorphism analysis. Soil and potato periderm were characterized by contents of carbon, nitrogen, phosphorus, sulphur, calcium, magnesium, and iron. Quality of organic matter was assessed by high performance liquid chromatography of soil extracts. The study demonstrated that the suppressive character of the fields is locally specific. At Zdirec, the suppressivity was associated with low txtB gene copies in bulk soil, while at Vyklantice site it was associated with low txtB gene copies in the tuberosphere. The differences were discussed with respect to the effect of abiotic conditions at Zdirec and interaction between potato plant and soil microbial community at Vyklantice. Soil pH, Ca soil content or cation concentrations, although different were not in the range to predict the disease severity. Low severity of common scab was associated with low content of soil C, N, C/N, Ca and Fe suggesting that oligotrophic conditions may be favorable to common scab suppression.

  7. A cross-site comparison of factors influencing soil nitrification rates in northeastern USA forested watersheds

    Science.gov (United States)

    Ross, D.S.; Wemple, B.C.; Jamison, A.E.; Fredriksen, G.; Shanley, J.B.; Lawrence, G.B.; Bailey, S.W.; Campbell, J.L.

    2009-01-01

    Elevated N deposition is continuing on many forested landscapes around the world and our understanding of ecosystem response is incomplete. Soil processes, especially nitrification, are critical. Many studies of soil N transformations have focused on identifying relationships within a single watershed but these results are often not transferable. We studied 10 small forested research watersheds in the northeastern USA to determine if there were common factors related to soil ammonification and nitrification. Vegetation varied between mixed northern hardwoods and mixed conifers. Watershed surface soils (Oa or A horizons) were sampled at grid or transect points and analyzed for a suite of chemical characteristics. At each sampling point, vegetation and topographic metrics (field and GIS-based) were also obtained. Results were examined by watershed averages (n = 10), seasonal/watershed averages (n = 28), and individual sampling points (n = 608). Using both linear and tree regression techniques, the proportion of conifer species was the single best predictor of nitrification rates, with lower rates at higher conifer dominance. Similar to other studies, the soil C/N ratio was also a good predictor and was well correlated with conifer dominance. Unlike other studies, the presence of Acer saccharum was not by itself a strong predictor, but was when combined with the presence of Betula alleghaniensis. Topographic metrics (slope, aspect, relative elevation, and the topographic index) were not related to N transformation rates across the watersheds. Although found to be significant in other studies, neither soil pH, Ca nor Al was related to nitrification. Results showed a strong relationship between dominant vegetation, soil C, and soil C/N. ?? 2008 Springer Science+Business Media, LLC.

  8. Soils

    International Nuclear Information System (INIS)

    Freudenschuss, A.; Huber, S.; Riss, A.; Schwarz, S.; Tulipan, M.

    2001-01-01

    For Austria there exists a comprehensive soil data collection, integrated in a GIS (geographical information system). The content values of pollutants (cadmium, mercury, lead, copper, mercury, radio-cesium) are given in geographical charts and in tables by regions and by type of soil (forests, agriculture, greenland, others) for the whole area of Austria. Erosion effects are studied for the Austrian region. Legal regulations and measures for an effective soil protection, reduction of soil degradation and sustainable development in Austria and the European Union are discussed. (a.n.)

  9. Soil to rice transfer factors for 210Pb: a study on rice grown in India

    International Nuclear Information System (INIS)

    Karunakara, N.; Rao, Chetan; Ujwal, P.; Yashodhara, I.; Sudeep Kumara; Somashekarappa, H.M.; Bhaskara Shenoy, K.; Ravi, P.M.

    2013-01-01

    India is the second largest producer of rice (Oryza sativa L.) in the world and rice is the essential component of the diet for the majority of the population of India. However, detailed studies aimed at evaluation of radionuclide transfer factors (F v ) for rice grown in India are almost non-existent. This paper presents soil to rice transfer factors for 210 Pb for rice grown in natural field conditions on the West Coast of India. A rice field was developed very close to the Kaiga nuclear power plant for the field studies. For a comparative study of radionuclide transfer factors, rice samples were also collected from the rice fields of nearby villages. The soil to un-hulled rice grain 210 Pb varied in the range <1.2 x10 -2 to 8.1 x 10 -1 with a mean of 1.4 x 10 -1 . The mean values of un-hulled grain to white rice processing retention factors (F r ) was 0.03 for 210 Pb. Using the processing retention factors the soil to white rice transfer factor was estimated and found to have the mean value of 4.2 x 10 -3 . The study has shown that the transfer of 210 Pb was retained in the root and its transfer to above ground organs of rice plant is significantly lower. (author)

  10. Factors affecting the local control of stereotactic body radiotherapy for lung tumors including primary lung cancer and metastatic lung tumors

    International Nuclear Information System (INIS)

    Hamamoto, Yasushi; Kataoka, Masaaki; Yamashita, Motohiro

    2012-01-01

    The purpose of this study was to identify factors affecting local control of stereotactic body radiotherapy (SBRT) for lung tumors including primary lung cancer and metastatic lung tumors. Between June 2006 and June 2009, 159 lung tumors in 144 patients (primary lung cancer, 128; metastatic lung tumor, 31) were treated with SBRT with 48-60 Gy (mean 50.1 Gy) in 4-5 fractions. Higher doses were given to larger tumors and metastatic tumors in principle. Assessed factors were age, gender, tumor origin (primary vs. metastatic), histological subtype, tumor size, tumor appearance (solid vs. ground glass opacity), maximum standardized uptake value of positron emission tomography using 18 F-fluoro-2-deoxy-D-glucose, and SBRT doses. Follow-up time was 1-60 months (median 18 months). The 1-, 2-, and 3-year local failure-free rates of all lesions were 90, 80, and 77%, respectively. On univariate analysis, metastatic tumors (p<0.0001), solid tumors (p=0.0246), and higher SBRT doses (p=0.0334) were the statistically significant unfavorable factors for local control. On multivariate analysis, only tumor origin was statistically significant (p=0.0027). The 2-year local failure-free rates of primary lung cancer and metastatic lung tumors were 87 and 50%, respectively. A metastatic tumor was the only independently significant unfavorable factor for local control after SBRT. (author)

  11. Soil Erodibility under Natural Rainfall Conditions as the K Factor of the Universal Soil Loss Equation and Application of the Nomograph for a Subtropical Ultisol

    Directory of Open Access Journals (Sweden)

    Elemar Antonino Cassol

    2018-05-01

    Full Text Available ABSTRACT: Erodibility represents the intrinsic susceptibility of the soil to the erosion process, represented by the K factor in the Universal Soil Loss Equation (USLE. In Brazil, there are few field experiments determined with a series larger than ten years of data, which are the most reliable for quantifying the K factor. The aim of this study was to determine the K factor of the USLE by the direct method, relating soil losses determined in the field under standard conditions to erosivity of rains, and by the analytic method, applying the Wischmeier nomograph. The data on soil loss by water erosion were obtained in a field experiment under natural rainfall conditions from 1976 to 1989 in an Ultisol at the Agronomic Experimental Station in Eldorado do Sul, RS, Brazil. The value of the K factor by the direct method was 0.0338 Mg ha h ha-1 MJ-1 mm-1, which is high, showing considerable susceptibility of the soil to erosion. From the analytical method, the K factor obtained was 0.0325 Mg ha h ha-1 MJ-1 mm-1, a value very close to that determined experimentally. Thus, the Wischmeier nomograph proved to be valid for determination of the K factor of the Ultisol under study. This method proved to be valid for this type of soil. These results can be used for calibration models based on the USLE.

  12. Application of Geomorphologic Factors for Identifying Soil Loss in Vulnerable Regions of the Cameron Highlands

    Directory of Open Access Journals (Sweden)

    Kahhoong Kok

    2018-03-01

    Full Text Available The main purpose of this study is to propose a methodology for identifying vulnerable regions in the Cameron Highlands that are susceptible to soil loss, based on runoff aggregation structure and the energy expenditure pattern of the natural river basin, within the framework of power law distribution. To this end, three geomorphologic factors, namely shear stress and stream power, as well as the drainage area of every point in the basin of interest, have been extracted using GIS, and then their complementary cumulative distributions are graphically analyzed by fitting them to power law distribution, with the purpose of identifying the sensitive points within the basin that are susceptible to soil loss with respect to scaling regimes of shear stress and stream power. It is observed that the range of vulnerable regions by the scaling regime of shear stress is much narrower than by the scaling regime of stream power. This result seems to suggest that shear stress is a scale-dependent factor, which does not follow power law distribution and does not adequately reflect the energy expenditure pattern of a river basin. Therefore, stream power is preferred as a more reasonable factor for the evaluation of soil loss. The methodology proposed in this study can be validated by visualizing the path of soil loss, which is generated from the hillslope process (characterized by the local slope to the valley through a fluvial process (characterized by the drainage area as well as the local slope.

  13. [Soil respiration dynamics and its controlling factors of typical vegetation communities on meadow steppes in the western Songnen Plain].

    Science.gov (United States)

    Wang, Ming; Liu, Xing-Tu; Li, Xiu-Jun; Zhang, Ji-Tao; Wang, Guo-Dong; Lu, Xin-Rui; Li, Xiao-Yu

    2014-01-01

    In order to accurately explore the soil respiration dynamics and its controlling factors of typical vegetation types in the western Songnen Plain, soil respiration rates of Chloris virgata, Puccinellia distans, Phragmites australis and Leymus chinensis communities were measured. The results showed that the diurnal curves of soil respiration rates of the four vegetation communities had simple peak values, which appeared at 11:00-15:00, and the valley values occurred at 21:00-1:00 or 3:00-5:00. The seasonal dynamic patterns of their soil respiration rates were similar, with the maximum (3.21-4.84 micromol CO2 x m(-2) x s(-1)) occurring in July and August and the minimum (0.46-1.51 micromol CO2 x m(-2) x s(-1)) in October. The soil respiration rates of the four vegetation communities had significant exponential correlations with ambient air temperature and soil temperature. Soil moisture, however, only played an important role in affecting the soil respiration rate of C. virgata community while air humidity near the soil surface was significantly correlated with the soil respiration rates of P. australis and L. chinensis communities. The soil salt contents seriously constrained the CO2 dioxide emission, and the soil pH, electrical conductivity (EC), exchangeable sodium percentage (ESP) could explain 87%-91% spatial variations of the soil respiration rate.

  14. Physiochemical, site, and bidirectional reflectance factor characteristics of uniformly moist soils. [Brazil, Spain and the United States of America

    Science.gov (United States)

    Stoner, E. R.; Baumgardner, M. F. (Principal Investigator)

    1980-01-01

    The author has identified the following significant results. The bidirectional reflectance factor (0.5 micron to 2.3 micron wavelength interval) and physiochemical properties of over 500 soils from 39 states, Brazil and Spain were measured. Site characteristics of soil temperature regime and moisture zone were used as selection criteria. Parent material and internal drainage were noted for each soil. At least five general types of soil reflectance curves were identified based primarily on the presence or absence of ferric iron absorption bands, organic matter content, and soil drainage characteristics. Reflectance in 10 bands across the spectrum was found to be negatively correlated with the natural log of organic matter content.

  15. Soil-to-plant transfer factors for natural radionuclides in the Brazilian cerrado region

    International Nuclear Information System (INIS)

    Jacomino, Vanusa M.F.; Oliveira, Kerley A.; Menezes, Maria Angela de B.; Mello, Jaime de; Silva, David F. da

    2009-01-01

    Large amounts of phosphogypsum produced have been attracting attention of Radiological Protection institutions and Environmental Protection agencies worldwide, given its high potential for environmental contamination. In Brazil, this material has been used for several decades, especially for agricultural purposes. Due to the presence of radionuclides in its composition, it is necessary to understand the mechanisms for natural radionuclide transfer in the soil/plant system and to evaluate if the use of phosphogypsum in soil contributes to increased exposition of humans to natural radioactivity. Experiments were accomplished in a greenhouse with lettuce cultivation in two types of soil (sandy and clayey) fertilized with four different amounts of phosphogypsum. Samples of phosphogypsum, soil, lettuce and drainage water were then analyzed for key radionuclides. 238 U and 232 Th analyses were carried out by Neutron Activation Analysis; 226 Ra, 228 Ra, and 210 Pb by analyzed by Gamma Spectrometry; and 210 Po by Alpha Spectrometry Technique. Finally, Transfer Factors of soil-plant were calculated as well as annual contribution to the effective dose due to the ingestion of lettuces. 22 '6Ra average specific activity in phosphogypsum samples (252 Bq kg -1 ) was below the maximum level recommended by USEPA, which is 370 Bq.kg -1 for agricultural use. Although most of the results for mean specific activity of radionuclides in lettuce presented values below the Minimum Detectable Activity (MDA), Transfer Factors were estimated for those conditions in which the mean specific activity proved to be superior to MDA. Values ranged from 1.8 10 -3 to 2.3 10 -2 for 232 Th; 3.5 10 - '2 to 4.1 10 -2 for 226 Ra, 2.4 10 -1 to 3.2 10 - '1 for 228 Ra, and 3.5 10 -2 to 8.5 10 -2 for 210 Po, depending on the type of soil used for planting vegetables. In general, results obtained in the present study indicated that mobility of radionuclides was low in both soils studied. Calculated effective

  16. Soil-to-plant transfer factors for natural radionuclides in the Brazilian cerrado region

    Energy Technology Data Exchange (ETDEWEB)

    Jacomino, Vanusa M.F.; Oliveira, Kerley A.; Menezes, Maria Angela de B., E-mail: vmfj@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Mello, Jaime de; Silva, David F. da, E-mail: jwvmello@ufv.b [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Solos; Siqueira, Maria C.; Taddei, Maria H.; Dias, Fabiana F., E-mail: mc_quimica@hotmail.co, E-mail: mhtaddei@cnen.gov.b, E-mail: fdias@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN-MG), Pocos de Caldas, MG (Brazil). Lab. de Pocos de Caldas (LAPOC)

    2009-07-01

    Large amounts of phosphogypsum produced have been attracting attention of Radiological Protection institutions and Environmental Protection agencies worldwide, given its high potential for environmental contamination. In Brazil, this material has been used for several decades, especially for agricultural purposes. Due to the presence of radionuclides in its composition, it is necessary to understand the mechanisms for natural radionuclide transfer in the soil/plant system and to evaluate if the use of phosphogypsum in soil contributes to increased exposition of humans to natural radioactivity. Experiments were accomplished in a greenhouse with lettuce cultivation in two types of soil (sandy and clayey) fertilized with four different amounts of phosphogypsum. Samples of phosphogypsum, soil, lettuce and drainage water were then analyzed for key radionuclides. {sup 238}U and {sup 232}Th analyses were carried out by Neutron Activation Analysis; {sup 226}Ra, {sup 228}Ra, and {sup 210}Pb by analyzed by Gamma Spectrometry; and {sup 210}Po by Alpha Spectrometry Technique. Finally, Transfer Factors of soil-plant were calculated as well as annual contribution to the effective dose due to the ingestion of lettuces. {sup 22}'6Ra average specific activity in phosphogypsum samples (252 Bq kg{sup -1}) was below the maximum level recommended by USEPA, which is 370 Bq.kg{sup -1} for agricultural use. Although most of the results for mean specific activity of radionuclides in lettuce presented values below the Minimum Detectable Activity (MDA), Transfer Factors were estimated for those conditions in which the mean specific activity proved to be superior to MDA. Values ranged from 1.8 10{sup -3} to 2.3 10{sup -2} for {sup 232}Th; 3.5 10{sup -}'2 to 4.1 10{sup -2} for {sup 226}Ra, 2.4 10{sup -1} to 3.2 10{sup -}'1 for {sup 228}Ra, and 3.5 10{sup -2} to 8.5 10{sup -2} for {sup 210}Po, depending on the type of soil used for planting vegetables. In general, results

  17. Meta-analysis of the effects of soil properties, site factors and experimental conditions on solute transport

    Directory of Open Access Journals (Sweden)

    J. K. Koestel

    2012-06-01

    Full Text Available Preferential flow is a widespread phenomenon that is known to strongly affect solute transport in soil, but our understanding and knowledge is still poor of the site factors and soil properties that promote it. To investigate these relationships, we assembled a database from the peer-reviewed literature containing information on 733 breakthrough curve experiments under steady-state flow conditions. Most of the collected experiments (585 of the 733 datasets had been conducted on undisturbed soil columns, although some experiments on repacked soil, clean sands, and glass beads were also included. In addition to the apparent dispersivity, we focused our attention on three indicators of preferential solute transport: namely the 5%-arrival time, the holdback factor, and the ratio of piston-flow and average transport velocities. Our results suggest that, in contrast to the 5%-arrival time and the holdback factor, the piston-flow to transport velocity ratio is not related to preferential macropore transport but rather to the exclusion or retardation of the applied tracer. Confirming that the apparent longitudinal dispersivity is positively correlated with the travel distance of the tracer, our results also illustrate that this relationship is refined if the normalized 5%-tracer arrival time is also taken into account. In particular, we found that the degree of preferential solute transport increases with apparent dispersivity and decreases with travel distance. A similar but weaker relationship was observed between apparent dispersivity, 5%-tracer arrival time, and lateral observation scale, such that the degree of preferential transport increases with lateral observation scale. However, we also found that the travel distance and the lateral observation scale in the investigated dataset are correlated, which makes it difficult to distinguish their influence on these transport characteristics. We also found that the strength of preferential transport

  18. Prognostic factors for head and neck cancer of unknown primary including the impact of human papilloma virus infection.

    Science.gov (United States)

    Axelsson, Lars; Nyman, Jan; Haugen-Cange, Hedda; Bove, Mogens; Johansson, Leif; De Lara, Shahin; Kovács, Anikó; Hammerlid, Eva

    2017-06-10

    Head and neck cancer of unknown primary (HNCUP) is rare and prospective studies are lacking. The impact of different prognostic factors such as age and N stage is not completely known, the optimal treatment is not yet established, and the reported survival rates vary. In the last decade, human papilloma virus (HPV) has been identified as a common cause of and important prognostic factor in oropharyngeal cancer, and there is now growing interest in the importance of HPV for HNCUP. The aim of the present study on curatively treated HNCUP was to investigate the prognostic importance of different factors, including HPV status, treatment, and overall survival. A search for HNCUP was performed in the Swedish Cancer Registry, Western health district, between the years 1992-2009. The medical records were reviewed, and only patients with squamous cell carcinoma or undifferentiated carcinoma treated with curative intent were included. The tumor specimens were retrospectively analyzed for HPV with p16 immunostaining. Sixty-eight patients were included. The mean age was 59 years. The majority were males, and had N2 tumors. Sixty-nine percent of the tumors were HPV positive using p16 staining. Patients who were older than 70 years, patients with N3-stage tumors, and patients with tumors that were p16 negative had a significantly worse prognosis. The overall 5-year survival rate for patients with p16-positive tumors was 88% vs 61% for p16-negative tumors. Treatment with neck dissection and postoperative radiation or (chemo) radiation had 81 and 88% 5-year survival rates, respectively. The overall and disease-free 5-year survival rates for all patients in the study were 82 and 74%. Curatively treated HNCUP had good survival. HPV infection was common. Independent prognostic factors for survival were age over 70 years, HPV status and N3 stage. We recommend that HPV analysis should be performed routinely for HNCUP. Treatment with neck dissection and postoperative radiation or

  19. Potential microbial risk factors related to soil amendments and irrigation water of potato crops.

    Science.gov (United States)

    Selma, M V; Allende, A; López-Gálvez, F; Elizaquível, P; Aznar, R; Gil, M I

    2007-12-01

    This study assesses the potential microbial risk factors related to the use of soil amendments and irrigation water on potato crops, cultivated in one traditional and two intensive farms during two harvest seasons. The natural microbiota and potentially pathogenic micro-organisms were evaluated in the soil amendment, irrigation water, soil and produce. Uncomposted amendments and residual and creek water samples showed the highest microbial counts. The microbial load of potatoes harvested in spring was similar among the tested farms despite the diverse microbial levels of Listeria spp. and faecal coliforms in the potential risk sources. However, differences in total coliform load of potato were found between farms cultivated in the autumn. Immunochromatographic rapid tests and the BAM's reference method (Bacteriological Analytical Manual; AOAC International) were used to detect Escherichia coli O157:H7 from the potential risk sources and produce. Confirmation of the positive results by polymerase chain reaction procedures showed that the immunochromatographic assay was not reliable as it led to false-positive results. The potentially pathogenic micro-organisms of soil amendment, irrigation water and soil samples changed with the harvest seasons and the use of different agricultural practices. However, the microbial load of the produce was not always influenced by these risk sources. Improvements in environmental sample preparation are needed to avoid interferences in the use of immunochromatographic rapid tests. The potential microbial risk sources of fresh produce should be regularly controlled using reliable detection methods to guarantee their microbial safety.

  20. Comparison of transfer factors of Sr-85 and Cs-134 for soils and crops of Greece

    International Nuclear Information System (INIS)

    Skarlou, V.; Papanicolaou, E. P.; Nobeli, C.

    1994-01-01

    The transfer of Sr-85 and Cs-134 from soil to plant (CR) was studied in two successive and similar in design glasshouse experiments. Six plant species (wheat, alfalfa, radish, string bean, cucumber, lettuce - only for Sr-85 - and endives - only for Cs-134), were grown in pots on eight Greek soils differing significantly in their physical and chemical properties. After the necessary measurements and analyses, big differences were detected in the transfer factors of both radionuclides with the soil types. The CRs of Sr-85 were higher than those of Cs-134 and for the tested crops and soils ranged between 0.3 and 36.5 for Sr-85 and between < 0.01 and 1.72 for Cs-134. The CRs of grains and seeds were much lower than those of leafy material for Sr-85 while the difference was not so high for Cs-134. The correlation between CRs and pH, negative in all cases, was significant or highly significant for all tested crops or plant parts (for Sr-85 r-bar = - 0.89, for Cs-134 r-bar = - 0.82). The values of CRs indicated a trend for negative correlation with other soil properties (cation exchange capacity-CEC, clay %). From exchangeable cations, exchangeable (Ca + Mg) as well as exchangeable bases, expressed as percentages of CEC, gave a significant or highly significant correlation with CRs of both radionuclides. (author)

  1. Factors of the accumulation of heavy metals and metalloids at geochemical barriers in urban soils

    Science.gov (United States)

    Kosheleva, N. E.; Kasimov, N. S.; Vlasov, D. V.

    2015-05-01

    The bulk contents and concentrations of mobile (extracted by an ammonium acetate buffer with EDTA) Cd, Pb, Sb, As, Bi, Zn, and Cu were determined in the surface horizons of urban soils in the Eastern administrative okrug of Moscow. The regression analysis showed that the accumulation of these metals and metalloids in the soils is controlled by the physicochemical soil properties and by number of anthropogenic factors and landscape conditions (geochemical position, type of loose deposits, character of land use, dust load, vehicle emissions, building pattern, percent of green areas, and the extent of sealed soils). The precipitation of studied elements on the geochemical barriers had the following regularities: Cd, Cu, and Zn accumulated on the alkaline barriers; Bi, Sb, As, Cu, Pb, and Zn, on chemisorption barriers; Sb, As, and Pb, on organomineral barriers; and Cd and Cu, on the sorption-sedimentation barriers. Technogenic transformation of the physicochemical properties of urban soils resulted in the increase of the mean bulk contents of heavy metals and metalloids by 33-99%; the portion of elements fixed on the geochemical barriers increased by 26-50%.

  2. effective hydraulic conductivity for a soil of variable pore size

    African Journals Online (AJOL)

    eobe

    Keywords: hydraulic conductivity, soil, infiltration, permeability, water. 1. INTRODUCTION. INTRODUCTION. INTRODUCTION. Accurate determination of hydraulic conductivity is very crucial for infiltration and runoff estimation. Factors which affect water infiltration in the soil include hydraulic conductivity, wetting front and soil.

  3. Environmental and Geographical Factors Structure Soil Microbial Diversity in New Caledonian Ultramafic Substrates: A Metagenomic Approach.

    Directory of Open Access Journals (Sweden)

    Véronique Gourmelon

    Full Text Available Soil microorganisms play key roles in ecosystem functioning and are known to be influenced by biotic and abiotic factors, such as plant cover or edaphic parameters. New Caledonia, a biodiversity hotspot located in the southwest Pacific, is one-third covered by ultramafic substrates. These types of soils are notably characterised by low nutrient content and high heavy metal concentrations. Ultramafic outcrops harbour diverse vegetation types and remarkable plant diversity. In this study, we aimed to assess soil bacterial and fungal diversity in New Caledonian ultramafic substrates and to determine whether floristic composition, edaphic parameters and geographical factors affect this microbial diversity. Therefore, four plant formation types at two distinct sites were studied. These formations represent different stages in a potential chronosequence. Soil cores, according to a given sampling procedure, were collected to assess microbial diversity using a metagenomic approach, and to characterise the physico-chemical parameters. A botanical inventory was also performed. Our results indicated that microbial richness, composition and abundance were linked to the plant cover type and the dominant plant species. Furthermore, a large proportion of Ascomycota phylum (fungi, mostly in non-rainforest formations, and Planctomycetes phylum (bacteria in all formations were observed. Interestingly, such patterns could be indicators of past disturbances that occurred on different time scales. Furthermore, the bacteria and fungi were influenced by diverse edaphic parameters as well as by the interplay between these two soil communities. Another striking finding was the existence of a site effect. Differences in microbial communities between geographical locations may be explained by dispersal limitation in the context of the biogeographical island theory. In conclusion, each plant formation at each site possesses is own microbial community resulting from

  4. Soil factors involved in the diversity and structure of soil bacterial communities in commercial organic olive orchards in Southern Spain.

    Science.gov (United States)

    Landa, B B; Montes-Borrego, M; Aranda, S; Soriano, M A; Gómez, J A; Navas-Cortés, J A

    2014-04-01

    Nowadays, there is a tendency in olive production systems to reduce tillage or keep a vegetative cover to reduce soil erosion and degradation. However, there is scarce information on the effects of different soil management systems (SMS) in soil bacterial community composition of olive groves. In this study, we have evaluated the effects of soil type and different SMS implemented to control weeds in the structure and diversity of bacterial communities of 58 soils in the two geographic areas that best represent the organic olive production systems in Spain. Bacterial community composition assessed by frequency and intensity of occurrence of terminal restriction profiles (TRFs) derived from terminal restriction fragment length polymorphism (T-RFLP) analysis of amplified 16S ribosomal deoxyribonucleic acid were strongly correlated with soil type/field site (Eutric/Calcaric) that differed mainly in soil particle size distribution and soil pH, followed by a strong effect of SMS, in that order. Canonical discriminant (CD) analysis of TRFs properly classified all of the olive orchard soils as belonging to their respective soil type or SMS. Furthermore, only a small set of TRFs were enough to clearly and significantly differentiate soil samples according to soil type or SMS. Those specific TRFs could be used as bioindicators to assess the effect of changes in SMS aimed to enhance soil quality in olive production systems. © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd.

  5. Transfer factors of 137Cs and 9Sr from soil to trees in arid regions

    International Nuclear Information System (INIS)

    Al-Oudat, M.; Asfary, A.F.; Mukhalallti, H.; Al-Hamwi, A.; Kanakri, S.

    2006-01-01

    Transfer factors of 137 Cs and 9 Sr from contaminated soil (Aridisol) to olive, apricot trees and grape vines were determined under irrigated field conditions for four successive years. The transfer factors (calculated as Bq kg -1 dry plant material per Bq kg -1 dry soil) of both radionuclides varied among tree parts and were highest in olive and apricot fruits. However, the values for 9 Sr were much higher than those for 137 Cs in all plant parts. The geometric mean of the transfer factors in olives, apricots and grapes were 0.007, 0.095 and 0.0023 for 137 Cs and 0.093, 0.13 and 0.08 for 9 Sr, respectively, and were negligible in olive oil for both radionuclides. The transfer factors of both radionuclides were similar to, or in the lower limits of, those obtained in other areas of the world. This could be attributed to differences in soil characteristics: higher pH, lower organic matter, high clay content, and higher exchangeable potassium and calcium

  6. Transfer factors for the „soil-cereals” system in the region of Pcinja, Serbia

    Directory of Open Access Journals (Sweden)

    Marković Jelena S.

    2016-01-01

    Full Text Available The aim of the paper was to estimate the values of transfer factors for natural radionuclides (40K, 226Ra, 232Th, 235U, and 238U and 137Cs from soil to plants (cereals: wheat, corn and barley as important parameters for the agricultures in the selection of the location and the sort of cereals to be planted on. The results presented in this paper refer to the „soil-cereals” system in the region of Pcinja, Serbia. Total of 9 samples of soil and 7 samples of cereals were measured in the Department of Radiation and Environmental Protection, Vinca Institute of Nuclear Sciences, using three high-purity germanium detectors for gamma spectrometry measurements. In all the samples, transfer factors for 226Ra are significantly lower than for 40K, but they are all in good agreement with the literature data. On the three investigated locations, the calculated values of transfer factors for 40K were in the range of 0.144 to 0.392, while in the case of 226Ra, the transfer factors ranged from 0.008 to 0.074. Only one value (0.051 was obtained for transfer factor of 232Th. Specific activities of 137Cs, as well as uranium isotopes, in all the investigated cereal samples, were below minimal detectable activity concentrations. Also, the absorbed dose rate and the annual absorbed dose from the natural radionuclides in the soil, were calculated. The absorbed dose rate ranged from 49-86 nSv/h, while the annual absorbed dose ranged from 0.061-0.105 mSv. The measurements presented in this manuscript are the first to be conducted in the region of Pcinja, thus providing the results that can be used as a baseline for future measurements and monitoring.

  7. Transfer Factor of Radioactive Cs and Sr from Egyptian Soils to Roots and Leafs of Wheat Plant

    International Nuclear Information System (INIS)

    Abu Khadra, S.A.; Abdel Fattah, A.T.; Eissa, H.S.; Abdel Sabour, M.F.

    2009-01-01

    Transfer factors (TFs) of long lived radionuclide such as 137 Cs and 90 Sr from three different Egyptian soils type to wheat plant have been studied by radiotracer experiments. Most typical Egyptian soils (sandy, sandy loam and clayey) from three different locations (Al -Oboor, Abu- Zaabal and Shebeen cities) were selected for the experiments carried out under outdoor conditions. The plant selected was wheat because the high consumption of wheat in Egypt. In the present study radioactive strontium and caesium uptake from different types of soil was investigated .These radionuclide showed a considerable difference in their distribution within the plant .The results showed that soil type influences the transfer factors. Sandy soil resulted in the highest transfer factor for both (Cs and Sr) from soil to wheat. TFs for leafs were higher than those for roots in case of 90 Sr (for all types of soil). However, TFs of ( 137 Cs) for roots were higher than those for leafs for all soils. Grains of the wheat showed the lowest transfer factor for the Cs and Sr (for all types of soil)

  8. Factors controlling regional differences in forest soil emission of nitrogen oxides (NO and N2O

    Directory of Open Access Journals (Sweden)

    K. Pilegaard

    2006-01-01

    Full Text Available Soil emissions of NO and N2O were measured continuously at high frequency for more than one year at 15 European forest sites as part of the EU-funded project NOFRETETE. The locations represent different forest types (coniferous/deciduous and different nitrogen loads. Geographically they range from Finland in the north to Italy in the south and from Hungary in the east to Scotland in the west. The highest NO emissions were observed from coniferous forests, whereas the lowest NO emissions were observed from deciduous forests. The NO emissions from coniferous forests were highly correlated with N-deposition. The site with the highest average annual emission (82 μg NO-N m−2 h−1 was a spruce forest in South-Germany (Höglwald receiving an annual N-deposition of 2.9 g m−2. NO emissions close to the detection limit were observed from a pine forest in Finland where the N-deposition was 0.2 g N m−2 a−1. No significant correlation between N2O emission and N-deposition was found. The highest average annual N2O emission (20 μg N2O-N m−2 h−1 was found in an oak forest in the Mátra mountains (Hungary receiving an annual N-deposition of 1.6 g m−2. N2O emission was significantly negatively correlated with the C/N ratio. The difference in N-oxide emissions from soils of coniferous and deciduous forests may partly be explained by differences in N-deposition rates and partly by differences in characteristics of the litter layer and soil. NO was mainly derived from nitrification whereas N2O was mainly derived from denitrification. In general, soil moisture is lower at coniferous sites (at least during spring time and the litter layer of coniferous forests is thick and well aerated favouring nitrification and thus release of NO. Conversely, the higher rates of denitrification in deciduous forests due to a compact and moist litter layer lead to N2O production and NO consumption in the soil. The two factors soil moisture and soil temperature are

  9. Factors that contribute to biomarker responses in humans including a study in individuals taking Vitamin C supplementation.

    Science.gov (United States)

    Anderson, D

    2001-09-01

    It is possible in many situations to identify humans exposed to potentially toxic materials in the workplace and in the environment. As in most human studies, there tends to be a high degree of interindividual variability in response to chemical insults. Some non-exposed control individuals exhibit as high a level of damage as some exposed individuals and some of these have levels of damage as low as many of the controls. Thus, it is only the mean values of the groups that can substantiate an exposure-related problem; the data on an individual basis are still of limited use. While human lymphocytes remain the most popular cell type for monitoring purposes, sperm, buccal, nasal, epithelial and placental cells are also used. However, for interpretation of responses, the issue of confounding factors must be addressed. There are endogenous confounding factors, such as age, gender, and genetic make-up and exogenous ones, including lifestyle habits (smoking, drinking, etc.) There are biomarkers of exposure, effect/response and susceptibility and the last may be influenced by the genotype and polymorphism genes existing in a population. From our own studies, confounding effects on cytogenetic damage and ras oncoproteins will be considered in relation to workers exposed to vinyl chloride and petroleum emissions and to volunteers taking Vitamin C supplementation. Smoking history, exposure and duration of employment affected the worker studies. For petroleum emissions, so did gender and season of exposure. For the non-smoking volunteer Vitamin C supplementation study, cholesterol levels, plasma Vitamin C levels, lipid peroxidation products and DNA damage in the Comet assay were also measured. Gender affected differences in Vitamin C levels, antioxidant capacity and the number of chromosome aberrations induced by bleomycin challenge in vitro. The results were the same for both high and low cholesterol subjects. The relationship between biomarkers and the various factors which

  10. Parental concern about vaccine safety in Canadian children partially immunized at age 2: a multivariable model including system level factors.

    Science.gov (United States)

    MacDonald, Shannon E; Schopflocher, Donald P; Vaudry, Wendy

    2014-01-01

    Children who begin but do not fully complete the recommended series of childhood vaccines by 2 y of age are a much larger group than those who receive no vaccines. While parents who refuse all vaccines typically express concern about vaccine safety, it is critical to determine what influences parents of 'partially' immunized children. This case-control study examined whether parental concern about vaccine safety was responsible for partial immunization, and whether other personal or system-level factors played an important role. A random sample of parents of partially and completely immunized 2 y old children were selected from a Canadian regional immunization registry and completed a postal survey assessing various personal and system-level factors. Unadjusted odds ratios (OR) and adjusted ORs (aOR) were calculated with logistic regression. While vaccine safety concern was associated with partial immunization (OR 7.338, 95% CI 4.138-13.012), other variables were more strongly associated and reduced the strength of the relationship between concern and partial immunization in multivariable analysis (aOR 2.829, 95% CI 1.151-6.957). Other important factors included perceived disease susceptibility and severity (aOR 4.629, 95% CI 2.017-10.625), residential mobility (aOR 3.908, 95% CI 2.075-7.358), daycare use (aOR 0.310, 95% CI 0.144-0.671), number of needles administered at each visit (aOR 7.734, 95% CI 2.598-23.025) and access to a regular physician (aOR 0.219, 95% CI 0.057-0.846). While concern about vaccine safety may be addressed through educational strategies, this study suggests that additional program and policy-level strategies may positively impact immunization uptake.

  11. Risk factors for exposure to influenza a viruses, including subtype H5 viruses, in Thai free-grazing ducks.

    Science.gov (United States)

    Beaudoin, A L; Kitikoon, P; Schreiner, P J; Singer, R S; Sasipreeyajan, J; Amonsin, A; Gramer, M R; Pakinsee, S; Bender, J B

    2014-08-01

    Free-grazing ducks (FGD) have been associated with highly pathogenic avian influenza (HPAI) H5N1 outbreaks and may be a viral reservoir. In July-August 2010, we assessed influenza exposure of Thai FGD and risk factors thereof. Serum from 6254 ducks was analysed with enzyme-linked immunosorbent assay (ELISA) to detect antibodies to influenza A nucleoprotein (NP), and haemagglutinin H5 protein. Eighty-five per cent (5305 ducks) were seropositive for influenza A. Of the NP-seropositive sera tested with H5 assays (n = 1423), 553 (39%) were H5 ELISA positive and 57 (4%) suspect. Twelve per cent (74 of 610) of H5 ELISA-positive/suspect ducks had H5 titres ≥ 1 : 20 by haemagglutination inhibition. Risk factors for influenza A seropositivity include older age, poultry contact, flock visitors and older purchase age. Study flocks had H5 virus exposure as recently as March 2010, but no HPAI H5N1 outbreaks have been identified in Thailand since 2008, highlighting a need for rigorous FGD surveillance. © 2012 Blackwell Verlag GmbH.

  12. Soil-transmitted helminthiasis in rural south-west China: prevalence, intensity and risk factor analysis.

    Science.gov (United States)

    Mofid, Layla S; Bickle, Quentin; Jiang, Jin-Yong; Du, Zun-Wei; Patrick, Edward

    2011-05-01

    Only few studies in rural China have explored the epidemiology of intestinal helminth infections and identified risk factors for transmission. The study was carried out in Simao and Mengla counties, where single fecal samples were collected from 317 school-aged children and from 94 inhabitants of a single village. Fecal specimens were examined with the Kato-Katz thick smear method and examined for helminth eggs. Data regarding socio-demographic and behavioral risk factors were collected using questionnaires. In Simao County the overall soil-transmitted helminthes (STH) prevalence was 40.2% (2.7, 5.4 and 35.7% for ascariasis, trichuriasis and hookworm infection, respectively). The STH infection rates were significantly higher in Mengla County, with an overall prevalence of 68.3% (19.0, 34.6 and 47.3% for ascariasis, trichuriasis and hookworm infection, respectively). Females were less likely to be infected with Trichuris trichiura (OR 0.29; 95% CI 0.15-0.56) and with hookworms (OR 0.55; 95% CI 0.33-0.93) than males. Hookworm infections were more prevalent among those 12 years of age or older (OR 2.9; 95% CI 1.2-7.1). Children of mothers with educational attainment of secondary school or higher had a protective effect against T. trichiura (OR 0.18; 95% CI 0.06-0.54) and hookworm (OR 0.21; 95% CI 0.09-0.51) infections. In the village survey, hookworm was the most prevalent species (62.8%) with infection seen in those 50 years of age and older. Based on recommended intervention strategies by the World Health Organization, Simao County should opt for school-based deworming once each year, while Mengla County should implement a similar strategy biannually, but should include the elderly population.

  13. Seasonal abundance of soil arthropods in relation to meteorological and edaphic factors in the agroecosystems of Faisalabad, Punjab, Pakistan

    Science.gov (United States)

    Shakir, Muhammad Mussadiq; Ahmed, Sohail

    2015-05-01

    Soil arthropods are an important component of agroecosystems, contributing significantly to their biodiversity and functioning. However, seasonal patterns, population dynamics, and significant roles of these soil arthropods in improvement of soil structures and functions are influenced by many factors. The objective of the current study was to investigate soil arthropod abundance in relation to a blend of meteorological and edaphic factors and to find out the difference in abundance among various crops (sugarcane, cotton, wheat, alfalfa fodder, and citrus orchards). The arthropod sampling was done by pitfall traps and Tullgren extractions on fortnightly intervals. Soil temperature and relative humidity were noted on the field sites while analysis for soil pH, organic matter, and soil moisture contents were done in the laboratory. The rainfall data was obtained from an observatory. Results showed that significant differences were found in soil arthropod abundance across different sampling months and crops. Out of total 13,673 soil arthropods sampled, 38 % belonged to Collembola, followed by 15 % Hymenoptera, 15 % Acarina, 11 % Myriapods, 6 % Coleoptera, 5 % Orthoptera, and 5 % Araneae. Mean abundance per sample was highest in summer months as compared to winter. Overall abundance per sample was significantly different between all crops ( p Aranae, Coleoptera), least abundant (Dermaptera, Hemiptera, Diptera), and rare (Blattaria, Isoptera, Diplura, Lepidoptera). Soil temperature and soil organic matter showed significant positive correlation with abundance, while relative humidity was significantly negatively correlated. Soil moisture and soil pH showed no significant correlations while no correlation was found with total rainfall. PCA analysis revealed that soil surface arthropods were the major contributors of variation in overall abundance in extreme temperature months while microarthropods in low-temperature months. CCA analysis revealed the occurrence of

  14. Seasonal abundance of soil arthropods in relation to meteorological and edaphic factors in the agroecosystems of Faisalabad, Punjab, Pakistan.

    Science.gov (United States)

    Shakir, Muhammad Mussadiq; Ahmed, Sohail

    2015-05-01

    Soil arthropods are an important component of agroecosystems, contributing significantly to their biodiversity and functioning. However, seasonal patterns, population dynamics, and significant roles of these soil arthropods in improvement of soil structures and functions are influenced by many factors. The objective of the current study was to investigate soil arthropod abundance in relation to a blend of meteorological and edaphic factors and to find out the difference in abundance among various crops (sugarcane, cotton, wheat, alfalfa fodder, and citrus orchards). The arthropod sampling was done by pitfall traps and Tullgren extractions on fortnightly intervals. Soil temperature and relative humidity were noted on the field sites while analysis for soil pH, organic matter, and soil moisture contents were done in the laboratory. The rainfall data was obtained from an observatory. Results showed that significant differences were found in soil arthropod abundance across different sampling months and crops. Out of total 13,673 soil arthropods sampled, 38 % belonged to Collembola, followed by 15 % Hymenoptera, 15 % Acarina, 11 % Myriapods, 6 % Coleoptera, 5 % Orthoptera, and 5 % Araneae. Mean abundance per sample was highest in summer months as compared to winter. Overall abundance per sample was significantly different between all crops (p arthropods according to abundance, i.e., highly abundant (Collembola, Acarina, Myripoda, Hymenoptera), moderately abundant (Orthoptera, Aranae, Coleoptera), least abundant (Dermaptera, Hemiptera, Diptera), and rare (Blattaria, Isoptera, Diplura, Lepidoptera). Soil temperature and soil organic matter showed significant positive correlation with abundance, while relative humidity was significantly negatively correlated. Soil moisture and soil pH showed no significant correlations while no correlation was found with total rainfall. PCA analysis revealed that soil surface arthropods were the major contributors of variation in overall

  15. Determination of factors associated with natural soil suppressivity to potato common scab

    Czech Academy of Sciences Publication Activity Database

    Ságová-Marečková, M.; Daniel, O.; Omelka, M.; Krištůfek, Václav; Diviš, J.; Kopecký, J.

    2015-01-01

    Roč. 10, č. 1 (2015), e0116291 E-ISSN 1932-6203 R&D Projects: GA MZe QJ1210359 Grant - others:GA ČR(CZ) GPP201/11/P290 Program:GP Institutional support: RVO:60077344 Keywords : natural soil suppressivity * potato common scab * pathogenic bacteria Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 3.057, year: 2015

  16. Factors determining outcome in children with chronic constipation and faecal soiling.

    OpenAIRE

    Loening-Baucke, V

    1989-01-01

    To evaluate factors which might contribute to treatment failure in children with chronic constipation and soiling, we evaluated the history, physical findings, defecation dynamics, and anorectal function in 97 patients. We treated them with milk of magnesia, high fibre diet, and bowel training techniques and evaluated outcome at one year when 43% had recovered. Recovery rates were similar for boys and girls. Fifty seven per cent of the patients had not recovered. This group at the outset had ...

  17. Sound absorption coefficient in situ: an alternative for estimating soil loss factors.

    Science.gov (United States)

    Freire, Rosane; Meletti de Abreu, Marco Henrique; Okada, Rafael Yuri; Soares, Paulo Fernando; GranhenTavares, Célia Regina

    2015-01-01

    The relationship between the sound absorption coefficient and factors of the Universal Soil Loss Equation (USLE) was determined in a section of the Maringá Stream basin, Paraná State, by using erosion plots. In the field, four erosion plots were built on a reduced scale, with dimensions of 2.0×12.5m. With respect to plot coverage, one was kept with bare soil and the others contained forage grass (Brachiaria), corn and wheat crops, respectively. Planting was performed without any type of conservation practice in an area with a 9% slope. A sedimentation tank was placed at the end of each plot to collect the material transported. For the acoustic system, pink noise was used in the measurement of the proposed monitoring, for collecting information on incident and reflected sound pressure levels. In general, obtained values of soil loss confirmed that 94.3% of material exported to the basin water came from the bare soil plot, 2.8% from the corn plot, 1.8% from the wheat plot, and 1.1% from the forage grass plot. With respect to the acoustic monitoring, results indicated that at 16kHz erosion plot coverage type had a significant influence on the sound absorption coefficient. High correlation coefficients were found in estimations of the A and C factors of the USLE, confirming that the acoustic technique is feasible for the determination of soil loss directly in the field. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Spatial patterns of soil pH and the factors that influence them in plantation forests of northern China

    Science.gov (United States)

    Hong, Songbai; Liu, Yongwen; Piao, Shilong

    2017-04-01

    Climate and anthropogenic activities such as afforestation and nitrogen deposition all impact soil pH. Understanding the spatial pattern of soil pH and the factors that influence it can provide basic information for generating appropriate strategies for soil resource management and protection, especially in light of increasing anthropogenic influences and climate change. In this study, we investigated the spatial and vertical pattern of soil pH and evaluated the influence of climate and nitrogen deposition using 1647 soil profiles 1 meter in depth from 549 plots in plantation forests of northern China. We found that soil pH decreased from the southwest to the northeast in the study region and had a similar spatial pattern before and after afforestation. Furthermore, our results show that climate and nitrogen deposition fundamentally influence the pattern of soil pH. Specifically, increasing precipitation significantly decreased soil pH (with a mean rate of 0.3 for every 100 mm rainfall, ppH (0.13 for every degree centigrade, ppH (ppH directly and indirectly through climate-plant-soil interactions. As the risks from both climate change and nitrogen deposition increase, there is an urgent need to further understanding of soil pH dynamics and to develop informed policies to protect soil resources.

  19. Modelling nitrous oxide emissions from organic and conventional cereal-based cropping systems under different management, soil and climate factors

    DEFF Research Database (Denmark)

    Doltra, J; Olesen, Jørgen E; Báez, D

    2015-01-01

    Mitigation of greenhouse gas emissions from agriculture should be assessed across cropping systems and agroclimatic regions. In this study, we investigate the ability of the FASSET model to analyze differences in the magnitude of N2O emissions due to soil, climate and management factors in cereal...... on the seasonal soil N2O fluxes than the environmental factors. Overall, in its current version FASSET reproduced the effects of the different factors investigated on the cumulative seasonal soil N2O emissions but temporally it overestimated emissions from nitrification and denitrification on particular days when...... soil operations, ploughing or fertilization, took place. The errors associated with simulated daily soil N2O fluxes increased with the magnitude of the emissions. For resolving causes of differences in simulated and measured fluxes more intensive and temporally detailed measurements of N2O fluxes...

  20. Soil-plant transfer factors for Pu in the field and laboratory in relation to desorption from the solid phase

    International Nuclear Information System (INIS)

    Mudge, S.; Kelly, M.; Hamilton-Taylor, J.; Horrill, A.D.

    1990-01-01

    Laboratory hydroponics experiments using an environmentally contaminated sediment as source of Pu, were carried out to determine the soil-plant, soil solution-plant and root-plant transfer factors. Soil-plant transfer factors, calculated from field observations, varied according to the degree of animal usage and were more than two orders of magnitude larger than those from the laboratory experiments. The discrepancies between field and laboratory measurements are probably due to the complex sediment speciation and desorption chemistry of Pu. The transfer factors based on the solution or root activities are likely to provided a better estimate of the vegetation activity than those based on the solid phase activity. (author)

  1. Sensitivity Analysis of b-factor in Microwave Emission Model for Soil Moisture Retrieval: A Case Study for SMAP Mission

    Directory of Open Access Journals (Sweden)

    Dugwon Seo

    2010-05-01

    Full Text Available Sensitivity analysis is critically needed to better understand the microwave emission model for soil moisture retrieval using passive microwave remote sensing data. The vegetation b-factor along with vegetation water content and surface characteristics has significant impact in model prediction. This study evaluates the sensitivity of the b-factor, which is function of vegetation type. The analysis is carried out using Passive and Active L and S-band airborne sensor (PALS and measured field soil moisture from Southern Great Plains experiment (SGP99. The results show that the relative sensitivity of the b-factor is 86% in wet soil condition and 88% in high vegetated condition compared to the sensitivity of the soil moisture. Apparently, the b-factor is found to be more sensitive than the vegetation water content, surface roughness and surface temperature; therefore, the effect of the b-factor is fairly large to the microwave emission in certain conditions. Understanding the dependence of the b-factor on the soil and vegetation is important in studying the soil moisture retrieval algorithm, which can lead to potential improvements in model development for the Soil Moisture Active-Passive (SMAP mission.

  2. Transfer factors of radioiodine from volcanic-ash soil (Andosol) to crops

    International Nuclear Information System (INIS)

    Ban-Nai, Tadaaki; Muramatsu, Yasuyuki

    2003-01-01

    In order to obtain soil-to-plant transfer factors (TFs) of radioiodine from volcanic-ash soil to agricultural crops, we carried out radiotracer experiments. The mean values of TFs (on a wet weight basis) of radioiodine from Andosol to edible parts of crops were as follows: water dropwort, 0.24; lettuce, 0.00098; onion, 0.0011; radish, 0.0044; turnip, 0.0013 and eggplant, 0.00010. The mean value of the TFs of radioiodine for edible parts of wheat (on a dry weight basis) was 0.00015. We also studied the distributions of iodine in crops. There was a tendency for the TFs of leaves to be higher than those of tubers, fruits and grains. A very high TF was found for water dropwort, because this plant was cultivated under a waterlogged condition, in which iodine desorbed from soil into soil solution with a drop in the Eh value. The data obtained in this study should be helpful to assess the long-lived 129 I (half life: 1.57 x l0 7 yr) pathway related to the fuel cycle. (author)

  3. Cs-137 soil to plant transfer factors derived from pot experiments and field studies

    International Nuclear Information System (INIS)

    Horak, O.; Gerzabek, M.H.; Mueck, K.

    1989-11-01

    Soil to plant transfer factors (TF) of 137 Cs for different crop plants were determined in pot experiments, in outdoor experiments with plastic containers of 50 l volume, and in field studies. In all cases the soil contamination with 137 Cs resulted from fallout after the Chernobyl reactor accident. Mean TF derived for outdoor plants on a fresh weight basis, ranged from 0,0017 (leaf vegetables) to 0,059 (rye straw) and showed characteristic differences depending on plant part and species. Generally, for fruits and potato tubers a lower TF was found than for vegetative plant parts. Moreover, the data were compared with those from former experiments, carried out before the Chernobyl accident. There is a good agreement for cereals (with exception of rye) fruit vegetables and fodder crops, while actual TF are substantially lower for potatoes, leaf and root vegetables, but higher for rye. A significant negative correlation was observed between the TF and the soil activity concentrations for 137 Cs. In container experiments the TF were found to be influenced mainly by the clay content of the soil. 11 refs., 2 figs., 2 tabs. (Authors)

  4. Distribution of Soil Organic Carbon and the Influencing Factors in An Oasis Farmland Area

    Directory of Open Access Journals (Sweden)

    WANG Ze

    2014-08-01

    Full Text Available The soil organic carbon(SOC of a typical oasis farmland in middle part of Manasi county of Xinjiang was used as the research ob原 ject. Using remote sensing and lab analysis techniques, influences of soil texture, terrain, land uses, and crop types on SOC content of farmland were studied. Results showed that the SOC distribution in farmland of Manasi was mainly determined by comprehensive natural environmental factors. The SOC content decreased along with the increasing soil depth. For soil textures, the SOC content from high to low was clay loam>powder loam>silty loam. Slope direction had significantly positive correlations with SOC contents at 0~30 cm and 30~60 cm, while altitude and SOC content at 60~100 cm were significantly positive correlation. The SOC content of orchard was the highest, and the uncultivated land was the lowest under different land-use patterns. For different crop planting systems, the order of SOC content was corn field >wine grapes field>cotton field, and the difference was significant.

  5. Transfer factors of radioiodine from volcanic-ash soil (Andosol) to crops

    Energy Technology Data Exchange (ETDEWEB)

    Ban-Nai, Tadaaki; Muramatsu, Yasuyuki [National Inst. of Radiological Sciences, Chiba (Japan). Environmental and Toxicological Sciences Research Group

    2003-03-01

    In order to obtain soil-to-plant transfer factors (TFs) of radioiodine from volcanic-ash soil to agricultural crops, we carried out radiotracer experiments. The mean values of TFs (on a wet weight basis) of radioiodine from Andosol to edible parts of crops were as follows: water dropwort, 0.24; lettuce, 0.00098; onion, 0.0011; radish, 0.0044; turnip, 0.0013 and eggplant, 0.00010. The mean value of the TFs of radioiodine for edible parts of wheat (on a dry weight basis) was 0.00015. We also studied the distributions of iodine in crops. There was a tendency for the TFs of leaves to be higher than those of tubers, fruits and grains. A very high TF was found for water dropwort, because this plant was cultivated under a waterlogged condition, in which iodine desorbed from soil into soil solution with a drop in the Eh value. The data obtained in this study should be helpful to assess the long-lived {sup 129}I (half life: 1.57 x l0{sup 7} yr) pathway related to the fuel cycle. (author)

  6. RNA Sequencing Analysis Reveals Transcriptomic Variations in Tobacco (Nicotiana tabacum Leaves Affected by Climate, Soil, and Tillage Factors

    Directory of Open Access Journals (Sweden)

    Bo Lei

    2014-04-01

    Full Text Available The growth and development of plants are sensitive to their surroundings. Although numerous studies have analyzed plant transcriptomic variation, few have quantified the effect of combinations of factors or identified factor-specific effects. In this study, we performed RNA sequencing (RNA-seq analysis on tobacco leaves derived from 10 treatment combinations of three groups of ecological factors, i.e., climate factors (CFs, soil factors (SFs, and tillage factors (TFs. We detected 4980, 2916, and 1605 differentially expressed genes (DEGs that were affected by CFs, SFs, and TFs, which included 2703, 768, and 507 specific and 703 common DEGs (simultaneously regulated by CFs, SFs, and TFs, respectively. GO and KEGG enrichment analyses showed that genes involved in abiotic stress responses and secondary metabolic pathways were overrepresented in the common and CF-specific DEGs. In addition, we noted enrichment in CF-specific DEGs related to the circadian rhythm, SF-specific DEGs involved in mineral nutrient absorption and transport, and SF- and TF-specific DEGs associated with photosynthesis. Based on these results, we propose a model that explains how plants adapt to various ecological factors at the transcriptomic level. Additionally, the identified DEGs lay the foundation for future investigations of stress resistance, circadian rhythm and photosynthesis in tobacco.

  7. Evaluation of soil-plant transfer factors of iodine. Estimation of annual ingestion for iodine from the diet

    International Nuclear Information System (INIS)

    Saas, Arsene.

    1980-11-01

    The author presents the iodine middle contents of the soils and vegetables. A synthesis on the iodine evolution in the soils and vegetables allows to conclude that the vegetable absorption of this isotope is correlated with the isotopiquely exchangeable iodine of the soil. The soil-plant transfer-factors are calculated for the vegetables, cereals, fruits from the stable iodine quantitative analysis. The annual iodine ingestion has been estimated from the dietary of the European Communites areas. This one is a little different of the quantity estimated by CRESTA-LACOURLY-R 2979, yet the contribution by consummation unity is different [fr

  8. Improvements in scaling of counter-current imbibition recovery curves using a shape factor including permeability anisotropy

    Science.gov (United States)

    Abbasi, Jassem; Sarafrazi, Shiva; Riazi, Masoud; Ghaedi, Mojtaba

    2018-02-01

    Spontaneous imbibition is the main oil production mechanism in the water invaded zone of a naturally fractured reservoir (NFR). Different scaling equations have been presented in the literature for upscaling of core scale imbibition recovery curves to field scale matrix blocks. Various scale dependent parameters such as gravity effects and boundary influences are required to be considered in the upscaling process. Fluid flow from matrix blocks to the fracture system is highly dependent on the permeability value in the horizontal and vertical directions. The purpose of this study is to include permeability anisotropy in the available scaling equations to improve the prediction of imbibition assisted oil production in NFRs. In this paper, a commercial reservoir simulator was used to obtain imbibition recovery curves for different scenarios. Then, the effect of permeability anisotropy on imbibition recovery curves was investigated, and the weakness of the existing scaling equations for anisotropic rocks was demonstrated. Consequently, an analytical shape factor was introduced that can better scale all the curves related to anisotropic matrix blocks.

  9. Sampling and Mapping Soil Erosion Cover Factor for Fort Richardson, Alaska. Integrating Stratification and an Up-Scaling Method

    National Research Council Canada - National Science Library

    Wang, Guangxing; Gertner, George; Anderson, Alan B; Howard, Heidi

    2006-01-01

    When a ground and vegetation cover factor related to soil erosion is mapped with the aid of remotely sensed data, a cost-efficient sample design to collect ground data and obtain an accurate map is required...

  10. In-situ Mass Distribution Quotient (iMDQ) - A New Factor to Compare Bioavailability of Pesticides in Soils?

    Science.gov (United States)

    Schroll, R.; Folberth, C.; Scherb, H.; Suhadolc, M.; Munch, J. C.

    2009-04-01

    Aim of this work was the development of a new non-biological factor to determine microbial in-situ bioavailability of chemicals in soils. Pesticide residues were extracted from ten highly different agricultural soils that had been incubated with the 14C-herbicide isoproturon (IPU) under comparable soil conditions (water tension - 15 kPa; soil density 1.3 g cm 3). Two different pesticide extraction approaches were compared: (i) 14C-Pesticide residues were measured in the pore water (PW) which was extracted from soil by centrifugation; (ii) 14C-Pesticide residues were extracted from soil samples with an excess of water (EEW). We introduce the pesticide's in-situ mass distribution quotient (iMDQ) as a measure for pesticide bioavailability, which is calculated as a quotient of adsorbed and dissolved chemical amounts for both approaches (iMDQPW, iMDQEEW). Pesticide mineralization in soils served as a reference for real microbial availability. A highly significant correlation between iMDQPW and mineralization showed that pore water extraction is adequate to assess IPU bioavailability. In contrast, no correlation exists between IPU mineralization and its extractability from soil with an excess of water. Therefore, it can be concluded that soil equilibration at comparable conditions and subsequent pore water extraction is vital for a isoproturon bioavailability ranking of soils.

  11. Regional scale soil salinity assessment using remote sensing based environmental factors and vegetation indicators

    Science.gov (United States)

    Ma, Ligang; Ma, Fenglan; Li, Jiadan; Gu, Qing; Yang, Shengtian; Ding, Jianli

    2017-04-01

    Land degradation, specifically soil salinization has rendered large areas of China west sterile and unproductive while diminishing the productivity of adjacent lands and other areas where salting is less severe. Up to now despite decades of research in soil mapping, few accurate and up-to-date information on the spatial extent and variability of soil salinity are available for large geographic regions. This study explores the po-tentials of assessing soil salinity via linear and random forest modeling of remote sensing based environmental factors and indirect indicators. A case study is presented for the arid oases of Tarim and Junggar Basin, Xinjiang, China using time series land surface temperature (LST), evapotranspiration (ET), TRMM precipitation (TRM), DEM product and vegetation indexes as well as their second order products. In par-ticular, the location of the oasis, the best feature sets, different salinity degrees and modeling approaches were fully examined. All constructed models were evaluated for their fit to the whole data set and their performance in a leave-one-field-out spatial cross-validation. In addition, the Kruskal-Wallis rank test was adopted for the statis-tical comparison of different models. Overall, the random forest model outperformed the linear model for the two basins, all salinity degrees and datasets. As for feature set, LST and ET were consistently identified to be the most important factors for two ba-sins while the contribution of vegetation indexes vary with location. What's more, models performances are promising for the salinity ranges that are most relevant to agricultural productivity.

  12. Exploring plant factors for increasing phosphorus utilization from rock phosphates and native soil phosphates in acidic soils

    International Nuclear Information System (INIS)

    Feng Guanglin; Xiong Liming

    2002-01-01

    Six plant species with contrasting capacity in utilizing rock phosphates were compared with regard to their responses to phosphorus starvation in hydroponic cultures. Radish, buckwheat and oil rapeseed are known to have strong ability to use rock phosphates while ryegrass, wheat and sesbania are less efficient. Whereas other plants acidified their culture solution under P starvation (-P), radish plants make alkaline the solution. When neutralizing the pH of the solutions cultured with plants under either -P or + P conditions, solutions with P starved buckwheat, rapeseed, and radish had a higher ability to solubilize Al and Fe phosphates than did those cultured with sesbania, ryegrass and wheat. Characterization of organic ligands in the solutions identified that citrate and malate were the major organic anions exuded by rapeseed and radish. Besides citrate and malate, buckwheat exuded a large amount of tartrate under P starvation. In contrast, ryegrass, wheat and sesbania secreted only a limited amount of oxalic acid, regardless of P status. Changes in activities of phosphoenolpyruvate carboxylase, acid phosphatase, and nitrate reductase in these plants were also compared under P- sufficient or -deficient conditions. The results indicated that plant ability to use rock phosphates or soil phosphates is closely related to their responses toward P starvation. The diversity of P starvation responses was discussed in the context of co-evolution between plants and their environment. Approaches to use plant factors to enhance the effectiveness of rock phosphates were also discussed. (author)

  13. Transfer factors of some selected radionuclides (radioactive Cs, Sr, Mn, Co and Zn) from soil to leaf vegetables

    International Nuclear Information System (INIS)

    Ban-nai, Tadaaki; Muramatsu, Yasuyuki; Yanagisawa, Kei

    1995-01-01

    Transfer factors of radionuclides from soil to leaf vegetables (cabbage, Chinese cabbage, komatsuna, spinach and lettuce) have been studied by radiotracer experiments using Andosol as a representative of Japanese soils. The transfer factors of radioactive Cs, Sr, Mn, Co and Zn for edible parts of vegetables (average of five vegetables) were 0.11, 0.24, 0.61, 0.05 and 0.52, respectively. These values should be used in safety assessment for Japanese agricultural environment. The transfer factors of Mn, Co and Zn for spinach were higher than those for the other vegetables. The transfer factors of Cs for different organs of the leaf vegetables were rather homogeneous. The transfer factors of Sr and Mn were higher for older (outer) leaves than younger (inner) ones. In contrast to Sr and Mn, transfer factors of Zn for younger leaves were higher than those for older ones. The distribution ratios of the elements between soil-solution and soil were in the order Sr>Mn>Cs>Co>Zn, whereas the distribution ratios of the elements between plant and soil-solution were in the order Zn>Cs>Mn>Co>Sr. These results indicate that the selectivity for Sr by plants from the soil-solution was low and that for Zn was very high. (author)

  14. Modelling the effect of support practices (P-factor) on the reduction of soil erosion by water at European Scale

    NARCIS (Netherlands)

    Panagos, P.; Borrelli, P.; Meusburger, K.; van der Zanden, E.H.; Poesen, J.; Alewell, C.

    2015-01-01

    The USLE/RUSLE support practice factor (P-factor) is rarely taken into account in soil erosion risk modelling at sub-continental scale, as it is difficult to estimate for large areas. This study attempts to model the P-factor in the European Union. For this, it considers the latest policy

  15. Daily changes of radon concentration in soil gas under influence of atmospheric factors: room temperature, soil surface temperature and relative humidity

    Energy Technology Data Exchange (ETDEWEB)

    Lara, Evelise G.; Oliveira, Arno Heeren de, E-mail: evelise.lara@gmail.com, E-mail: heeren@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Rocha, Zildete; Rios, Francisco Javier, E-mail: rochaz@cdtn.br, E-mail: javier@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    This work aims at relating the daily change in the radon concentration in soil gas in a Red Yellow Acrisol (SiBCS) under influence of atmospheric factors: room temperature, soil surface temperature and relative humidity. The {sup 226}Ra, {sup 232}Th, U content and permeability were also performed. The measurements of radon soil gas were carried out by using an AlphaGUARD monitor. The {sup 226}Ra activity concentration was made by Gamma Spectrometry (HPGe); the permeability was carried out using the RADON-JOK permeameter and ICP-MS analysis to {sup 232}Th and U content. The soil permeability is 5.0 x 10{sup -12}, which is considered average. The {sup 226}Ra (22.2 ± 0.3 Bq.m{sup -3}); U content (73.4 ± 3.6 Bq.kg{sup -1}) and {sup 232}Th content (55.3 ± 4.0 Bq.kg{sup -1}) were considered above of average concentrations, according to mean values for soils typical (~ 35.0 Bq.kg{sup -1}) by UNSCEAR. The results showed a difference of 26.0% between the highest and the lowest concentration of radon in soil gas: at midnight (15.5 ± 1.0 kBq.m{sup -3}) and 3:00 pm, the highest mean radon concentration (21.0 ± 1.0 kBq.m{sup -3}). The room temperature and surface soil temperature showed equivalent behavior and the surface soil temperature slightly below room temperature during the entire monitoring time. Nevertheless, the relative humidity showed the highest cyclical behavior, showing a higher relationship with the radon concentration in soil gas. (author)

  16. Daily changes of radon concentration in soil gas under influence of atmospheric factors: room temperature, soil surface temperature and relative humidity

    International Nuclear Information System (INIS)

    Lara, Evelise G.; Oliveira, Arno Heeren de

    2015-01-01

    This work aims at relating the daily change in the radon concentration in soil gas in a Red Yellow Acrisol (SiBCS) under influence of atmospheric factors: room temperature, soil surface temperature and relative humidity. The 226 Ra, 232 Th, U content and permeability were also performed. The measurements of radon soil gas were carried out by using an AlphaGUARD monitor. The 226 Ra activity concentration was made by Gamma Spectrometry (HPGe); the permeability was carried out using the RADON-JOK permeameter and ICP-MS analysis to 232 Th and U content. The soil permeability is 5.0 x 10 -12 , which is considered average. The 226 Ra (22.2 ± 0.3 Bq.m -3 ); U content (73.4 ± 3.6 Bq.kg -1 ) and 232 Th content (55.3 ± 4.0 Bq.kg -1 ) were considered above of average concentrations, according to mean values for soils typical (~ 35.0 Bq.kg -1 ) by UNSCEAR. The results showed a difference of 26.0% between the highest and the lowest concentration of radon in soil gas: at midnight (15.5 ± 1.0 kBq.m -3 ) and 3:00 pm, the highest mean radon concentration (21.0 ± 1.0 kBq.m -3 ). The room temperature and surface soil temperature showed equivalent behavior and the surface soil temperature slightly below room temperature during the entire monitoring time. Nevertheless, the relative humidity showed the highest cyclical behavior, showing a higher relationship with the radon concentration in soil gas. (author)

  17. Soil microbiology and soil health assessment

    Science.gov (United States)

    Soil scientists have long recognized the importance of soil biology in ecological health. In particular, soil microbes are crucial for many soil functions including decomposition, nutrient cycling, synthesis of plant growth regulators, and degradation of synthetic chemicals. Currently, soil biologis...

  18. The role of soil biogeochemistry in wine taste: Soil factors influencing grape elemental composition, photosynthetic biomarkers and Cu/Zn isotopic signature of Vitis vinifera

    Science.gov (United States)

    Blotevogel, Simon; Oliva, Priscia; Darrozes, José; Viers, Jérôme; Audry, Stéphane; Courjault-Radé, Pierre; Orgogozo, Laurent; Le Guedard, Marina; Schreck, Eva

    2015-04-01

    to the geological difference. These soils differ in elemental compositions and bioavailability of mineral nutrients, preconditions for a potential influence on plants and wine. Elemental ratios of soils are partly transmitted to leaves and grapes of correspondent plants, including nutrients such as Ca. Plant photosynthetic functioning is significantly better on the limestone vineyard due to lower Cu bioavailability: Omega-3 values are negatively linked to Cu bioavailability in corresponding soils. These observations suggest a difference in organic molecule synthesis depending on the vineyard soil, which might include components relevant for taste and fermentation. Cu and Zn isotopic ratios do not differ between both soils. The main fractionation of Cu and Zn isotopes occurs at the soil-plant interface making those isotopes suitable tracers for uptake mechanisms. As a result Zn isotope ratios reveal a strong recycling of Zn in the soil-plant continuum. Our results show a significant influence of soil composition on grape composition, plant biochemistry and potentially wine taste. Determination of organic and sensorial composition of grapes and wine is ongoing and will be discussed in further communications.

  19. Characterisation of the rhizoremediation of petroleum-contaminated soil: effect of different influencing factors

    Directory of Open Access Journals (Sweden)

    J. C. Tang

    2010-12-01

    Full Text Available Pilot experiments were conducted to analyse the effect of different environmental factors on the rhizoremediation of petroleum-contaminated soil. Different plant species (cotton, ryegrass, tall fescue and alfalfa, the addition of fertilizer, different concentrations of total petroleum hydrocarbons (TPH in the soil, bioaugmentation with effective microbial agents (EMA and plant growth-promoting rhizobacteria (PGPR and remediation time were tested as influencing factors during the bioremediation process of TPH. The results show that the remediation process can be enhanced by different plant species. The order of effectiveness of the plants was the following: tall fescue > ryegrass > alfalfa > cotton. The degradation rate of TPH increased with increased fertilizer addition, and a moderate urea level of 20 g N (Nitrogen/m2 was best for both plant growth and TPH remediation. A high TPH content is toxic to plant growth and inhibits the degradation of petroleum hydrocarbons. The results showed that a 5% TPH content gave the best degradation in soil planted with ryegrass. Bioaugmentation with different bacteria and PGPR yielded the following results for TPH degradation: cotton+EMA+PGPR > cotton+EMA > cotton+PGPR > cotton > control. Rapid degradation of TPH was found at the initial period of remediation caused by the activity of microorganisms. A continuous increase of degradation rate was found during the 30–90 days period followed by a slow increase during the 90–150 days period. These results suggest that rhizoremediation can be enhanced with the proper control of different influencing factors that affect both plant growth and microbial activity in the rhizosphere environment.

  20. Psychological factors, including alexithymia, in the prediction of cardiovascular risk in HIV infected patients: results of a cohort study.

    Directory of Open Access Journals (Sweden)

    Giustino Parruti

    Full Text Available Psychological factors are known predictors of cardiovascular disease in many clinical settings, but data are lacking for HIV infection. We carried out a prospective cohort study to evaluate potential psychological predictors of preclinical and clinical vascular disease in HIV patients.HIV patients were consecutively enrolled. Demographics, viral and immune parameters and traditional cardiovascular predictors were considered; Intima-Media Thickness (c-IMT, continuous measure and Carotid Plaques (CPs, focal thickening ≥1.5 mm were investigated by B-mode ultrasonography; depressive symptoms by the Beck Depression Inventory (BDI-II, Type D personality (Distressed Personality or Type D by the DS14, alexithymia by the Toronto Alexithymia Scale (TAS-20. Vascular outcomes included transient ischemic attacks or stroke, acute coronary syndrome, myocardial or other organ infarction. We enrolled 232 HIV subjects, 73.9% males, aged 44.5±9.9 y, 38.2% with AIDS diagnosis, 18.3% untreated. Mean Nadir CD4 T-cell counts were 237.5±186.2/mmc. Of them, 224 (96.5% attended IMT measurements; 201 (86.6% attended both IMT assessment and psychological profiling. Mean follow-up was 782±308 days. Fifty-nine patients (29.4% had CPs at baseline. Nineteen patients (9.5% had ≥1 vascular event; 12 (6.0% died due to such events (n = 4 or any cause. At baseline cross-sectional multivariate analysis, increasing age, total cholesterol, current smoking and Alexithymia score≥50 were significantly associated with both increased cIMT (linear regression and CPs (logistic regression. At follow-up analysis, log-rank tests and Cox's regression revealed that only older age (p = 0.001, current smoking (p = 0.019 and alexithymia score≥50 (p = 0.013 were independently associated with vascular events.In HIV-infected subjects, the Alexithymic trait emerges as a strong predictor of increased IMT, presence of CPs and vascular events. Such results are preliminary and require

  1. Transfer factors of 137Cs and 90Sr from soil to some trees in Syria

    International Nuclear Information System (INIS)

    Al-Oudat, M.; Al-Asfary, A. F.; Mukalati, H.; Hamwi, A.; Kanakri, S.

    2004-12-01

    The transfer factor of Cs 137 and 90 Sr from contaminated soil (Aridisol = Yermosol according to FAO - UNESCO) to some common trees (olive, apricot, grape, pine, apple and lemon) were investigated under field condition for 3 to 6 years. There were large variation in transfer factors values among tree species, and between different parts of tree. The values in fruits for 137 Cs were: 0.011 (highest) in Apricot, 0.0071 in olive, and 0.0025 in vine, and about 0.0012 in olive oil (lowest). The mean transfer factor of 137 Cs in the one year old leaves and stems, ranged between 0.011 and 0.0093 in lemon (highest) and 0.0016 and 0.0015 in pine (lowest). The transfer factor values of 90 Sr were much higher than that of 137 Cs, they were in fruits: 0.13 in apricot, 0.093 in olive, and 0.075 in vine and 0.0053 in olive oil. The transfer factors values of 90 Sr ranged in one year old leaves between 2.89 (apple) and 0.1 (pine), while they ranged in one year old stems between 1.91 (apricot) and 0.16 (pine). The transfer factor of both 137 Cs and 90 Sr decrease in most trees parts with time especially in the one year old leaves, due to aging effects. The transfer factor values of 137 Cs and 90 Sr were lower than that reported for other areas. This might be due to the physical and chemical properties of the soil, where the soil used had a loamy clay structure with high ph (7.8) and high CEC (25.9 meq/100g), exchangeable potassium (1.6 meq/100g) and calcium (14.9 meq/100g), further more, climatic condition in the area, like high light intensity, high temperature and low air humidity, can lead to decrease the uptake of both 137 Cs and 90 Sr. (Authors)

  2. Affecting factors analysis of soil moisture for arid mining area based on TM images

    Energy Technology Data Exchange (ETDEWEB)

    Bian, Zheng-fu; Lei, Shao-gang; Chang, Lu-qun; Zhang, Ri-chen [Jiangsu Key Laboratory of Resources and Environmental Informatics Engineering, Xuzhou (China)

    2009-04-15

    The model for calculating soil moisture (SM) in terms of thermal inertia using thematic mapper (TM) image and MODIS image was developed. There was a remarkable difference between two sets of average SM calculated by limited field sampling points taken from two different sampling sites, mined site and unmined site, and there were not a distinct difference between two sets of average SM calculated by the model using TM image. Domain factors affecting the SM were analyzed. The SM is in inverse proportion to the elevation and in direct proportion to the vegetation index. Coal mining resulted in a change of soil infiltration capacity. The vertical filtration index increased at the mined site, thereafter, the condition to supply ground water changed,the soil surface transpiration increased and SM changed. A drop of ground water level caused by mining can affect plant growth. When the plant root is extends downwards to reach the zone of capillary zone, ground water will be available for plant growth. 18 refs., 2 figs., 5 tabs.

  3. Factors determining outcome in children with chronic constipation and faecal soiling.

    Science.gov (United States)

    Loening-Baucke, V

    1989-07-01

    To evaluate factors which might contribute to treatment failure in children with chronic constipation and soiling, we evaluated the history, physical findings, defecation dynamics, and anorectal function in 97 patients. We treated them with milk of magnesia, high fibre diet, and bowel training techniques and evaluated outcome at one year when 43% had recovered. Recovery rates were similar for boys and girls. Fifty seven per cent of the patients had not recovered. This group at the outset had more frequent soiling episodes, more severe constipation, were less likely to defecate water filled rectal balloons and to relax the external sphincter during defecation. In general girls had more severe constipation, abdominal pain, and a previous urinary tract infection than boys. Girls were more compliant during treatment and had less frequent soiling episodes at one year. Stepwise logistic regression showed that severe constipation, abnormal contraction of the external sphincter and pelvic floor during attempted defecation, and inability to defecate the 100 ml balloon in less than or equal to 1 min was significantly related to treatment failure. Defecation of smaller balloons, volumes for threshold of rectal sensation, critical volume and rectal contraction, and compliance with treatment could not predict treatment failure.

  4. Local adaptation in migrated interior Douglas-fir seedlings is mediated by ectomycorrhizas and other soil factors.

    Science.gov (United States)

    Pickles, Brian J; Twieg, Brendan D; O'Neill, Gregory A; Mohn, William W; Simard, Suzanne W

    2015-08-01

    Separating edaphic impacts on tree distributions from those of climate and geography is notoriously difficult. Aboveground and belowground factors play important roles, and determining their relative contribution to tree success will greatly assist in refining predictive models and forestry strategies in a changing climate. In a common glasshouse, seedlings of interior Douglas-fir (Pseudotsuga menziesii var. glauca) from multiple populations were grown in multiple forest soils. Fungicide was applied to half of the seedlings to separate soil fungal and nonfungal impacts on seedling performance. Soils of varying geographic and climatic distance from seed origin were compared, using a transfer function approach. Seedling height and biomass were optimized following seed transfer into drier soils, whereas survival was optimized when elevation transfer was minimised. Fungicide application reduced ectomycorrhizal root colonization by c. 50%, with treated seedlings exhibiting greater survival but reduced biomass. Local adaptation of Douglas-fir populations to soils was mediated by soil fungi to some extent in 56% of soil origin by response variable combinations. Mediation by edaphic factors in general occurred in 81% of combinations. Soil biota, hitherto unaccounted for in climate models, interacts with biogeography to influence plant ranges in a changing climate. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  5. Analytic of elements for the determination of soil->plant transfer factors

    International Nuclear Information System (INIS)

    Liese, T.

    1985-02-01

    This article describes a part of the conventional analytical work, which was done to determine soil to plant transfer factors. The analytical methods, the experiments to find out the best way of sample digestion and the resulting analytical procedures are described. Analytical methods are graphite furnace atomic absorption spectrometry (GFAAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). In case of ICP-AES the necessity of right background correction and correction of the spectral interferences is shown. The reliability of the analytical procedure is demonstrated by measuring different kinds of standard reference materials and by comparison of AAS and AES. (orig./HP) [de

  6. Influence of natural and anthropogenic factors on the dynamics of CO2 emissions from chernozems soil

    Science.gov (United States)

    Syabruk, Olesia

    2017-04-01

    Twentieth century marked a significant expansion of agricultural production. Soil erosion caused by human activity, conversion of forests and grasslands to cropland, desertification, burning nutrient residues, drainage, excessive cultivation led to intense oxidation of soil carbon to the atmosphere and allocation of additional amounts of CO2. According to the UN Intergovernmental Panel on Climate Change, agriculture is one of the main sources of greenhouse gases emissions to the atmosphere. The thesis reveals main patterns of the impact of natural and anthropogenic factors on CO2 emissions in the chernozems typical and podzolized in a Left-bank Forest-Steppe of Ukraine, seasonal and annual dynamics. New provisions for conducting monitoring CO2 emissions from soil were developed by combining observations in natural and controlled conditions, which allows isolating the impact of hydrological, thermal and trophic factors. During the research, the methods for operational monitoring of emission of carbon losses were improved, using a portable infrared gas analyzer, which allows receiving information directly in the field. It was determined that the volumes of emission losses of carbon chernozems typical and podzolized Left-bank Forest-Steppe of Ukraine during the growing season are 480-910 kg/ha and can vary depending on the soil treatment ±( 4,0 - 6,0) % and fertilizer systems ± (3,8 - 7,1) %. The significant impact of long application of various fertilizer systems and soil treatment on the intensity of carbon dioxide emissions was investigated. It was found that most emission occurs in organic- mineral fertilizers systems with direct seeding. The seasonal dynamics of the potential capacity of the soil to produce CO2 were researched. Under identical conditions of humidity and temperature it has maximum in June and July and the gradual extinction of the autumn. It was determined that the intensity of the CO2 emission from the surface of chernozem fluctuates daily from

  7. The molar H: Corg ratio of biochar is a key factor in mitigating N2O emissions from soil

    NARCIS (Netherlands)

    Cayuela, M.L.; Jeffery, S.L.; Zwieten, van L.

    2015-01-01

    A previously published meta-analysis of biochar impacts on soil N2O emissions by Cayuela et al. (2014) found a “grand mean” reduction in N2O emissions of 54 ± 6% following biochar application to soil. Here we update this analysis to include 26 additional manuscripts bringing the total to 56

  8. Factors influencing U(VI adsorption onto soil from a candidate very low level radioactive waste disposal site in China

    Directory of Open Access Journals (Sweden)

    Zuo Rui

    2016-01-01

    Full Text Available The properties of soil at disposal sites are very important for geological disposal of very low level radioactive waste in terms of U(VI. In this study, soil from a candidate very low level radioactive waste disposal site in China was evaluated for its capacity on uranium sorption. Specifically, the equilibrium time, initial concentration, soil particle, pH, temperature, and carbonate were evaluated. The results indicated that after 15-20 days of sorption, the Kd value fluctuated and stabilized at 355-360 mL/g. The adsorptive capacity of uranium was increased as the initial uranium concentration increased, while it decreased as the soil particle size increased. The pH value played an important role in the U(VI sorption onto soil, especially under alkaline conditions, and had a great effect on the sorption capacity of soil for uranium. Moreover, the presence of carbonate decreased the sorption of U(VI onto soil because of the role of the strong complexation of carbonate with U(VI in the groundwater. Overall, this study assessed the behavior of U(VI sorption onto natural soil, which would be an important factor in the geological barrier of the repository, has contribution on mastering the characteristic of the adsorption of uranium in the particular soil media for the process of very low level radioactive waste disposal.

  9. Soil transmitted helminths and associated factors among schoolchildren in government and private primary school in Jimma Town, Southwest Ethiopia.

    Science.gov (United States)

    Debalke, Serkadis; Worku, Amare; Jahur, Nejat; Mekonnen, Zeleke

    2013-11-01

    Soil transmitted helminth infections are among the most common human infections. They are distributed throughout the world with high prevalence rates in tropical and sub-tropical countries mainly because of lack of adequate sanitary facilities, inappropriate waste disposal systems, lack of safe water supply, and low socio-economic status. A comparative cross sectional study was conducted from December 2011 to June 2012 to determine and assess the prevalence of soil transmitted helminths and their associated factors among government and private primary school children. Stool samples were collected from 369 randomly selected children and examined microscopically for eggs of soil transmitted helminth following McMaster techniques. Soil samples were collected from different parts of the school compound and microscopic examination was performed for eggs of the helminths using sodium nitrate flotation technique. The overall prevalence rate of soil transmitted helminth infections in private and government schools was 20.9% and 53.5% respectively. T. trichiura was the most common soil transmitted helminth in both schools while hookworm infections were identified in government school students only. Type of school and sex were significantly associated with soil transmitted helminth. Soil contamination rate of the school compounds was 11.25% with predominant parasites of A. lumbricoides. Higher prevalence of soil transmitted helminth infection was found among government school students. Thus, more focus, on personal hygiene and sanitary facilities, should be given to children going to government schools.

  10. Principal factors of soil spatial heterogeneity and ecosystem services at the Central Chernozemic Region of Russia

    Science.gov (United States)

    Vasenev, Ivan; Valentini, Riccardo

    2013-04-01

    The essential spatial heterogeneity is mutual feature for most natural and man-changed soils at the Central Chernozemic Region of Russia which is not only one of the biggest «food baskets» in RF but very important regulator of ecosystem principal services at the European territory of Russia. The original spatial heterogeneity of dominated here forest-steppe and steppe Chernozems and the other soils has been further complicated by a specific land-use history and different-direction soil successions due to environmental changes and more than 1000-year history of human impacts. The carried out long-term researches of representative natural, rural and urban landscapes in Kursk, Orel, Tambov and Voronezh oblasts give us the regional multi-factorial matrix of elementary soil cover patterns (ESCP) with different land-use practices and history, soil-geomorphologic features, environmental and microclimate conditions. The validation and ranging of the limiting factors of ESCP regulation and development, ecosystem principal services, land functional qualities and agroecological state have been done for dominating and most dynamical components of ESCP regional-typological forms - with application of regional and local GIS, soil spatial patterns mapping, traditional regression kriging, correlation tree models. The outcomes of statistical modeling show the essential amplification of erosion, dehumification and CO2 emission, acidification and alkalization, disaggregation and overcompaction processes due to violation of agroecologically sound land-use systems and traditional balances of organic matter, nutrients, Ca and Na in agrolandscapes. Due to long-term intensive and out-of-balance land-use practices the famous Russian Chernozems begin to lose not only their unique natural features of (around 1 m of humus horizon, 4-6% of Corg and favorable agrophysical features), but traditional soil cover patterns, ecosystem services and agroecological functions. Key-site monitoring

  11. Seasonal variation and controlling factors of soil carbon effluxes in six vegetation types in southeast of Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Tagesson, Torbern (Dept. of Physical Geography and Ecosystem Analysis, Lund Univ., Lund (SE))

    2007-11-15

    Soil carbon effluxes of a pine stand, a spruce stand, a lichen rock, two oak stands and a meadow in the Laxemar investigation area in south-eastern Sweden (57 deg 5 N, 16 deg 7 E) have been measured with the closed chamber technique at 14 occasions between 23 of March 2004 and 10th of March 2005. Soil temperature at 10 cm depth, air temperature, soil moisture and photosynthetically active radiation (PAR) were also measured. Exponential regressions with soil respiration against air and soil temperature were used to estimate soil respiration between 15th of March 2004 and 14th of March 2005. A light response curve with Gross Primary Production (GPP) against PAR and a cubic regression with GPP against air temperature were used for modelling GPP in meadow for the growing season, 15th of March to 31st of October 2004. The exponential regressions with soil respiration against air and soil temperature explained on average 30.6% and 47.6% of the variation, respectively. Soil moisture had a linear limiting effect on soil respiration for all ecosystems but spruce, where soil moisture was the limiting factor above a threshold value of about 50%vol. In the forest ecosystems, GPP of the ground vegetation were not reducing soil carbon effluxes, while in meadow it was. In meadow, the light response curve with GPP against PAR explained 32.7% of the variation in GPP while the cubic regression against air temperature explained 33.9%. No significant effect of soil moisture on GPP was detected. The exponential regression equations with air and soil temperature against soil respiration could be used to temporally extrapolate the occasional field measurements. The light response curve with GPP against PAR and the cubic regression with GPP against air temperature could also be used for temporal extrapolation. From the modelled soil respiration, annual soil respiration for the ecosystems in Laxemar, during 15th of March 2004 to 14th of March 2005, were estimated to be between 0.56 and 1

  12. Divergence of dominant factors in soil microbial communities and functions in forest ecosystems along a climatic gradient

    Science.gov (United States)

    Xu, Zhiwei; Yu, Guirui; Zhang, Xinyu; He, Nianpeng; Wang, Qiufeng; Wang, Shengzhong; Xu, Xiaofeng; Wang, Ruili; Zhao, Ning

    2018-03-01

    Soil microorganisms play an important role in regulating nutrient cycling in terrestrial ecosystems. Most of the studies conducted thus far have been confined to a single forest biome or have focused on one or two controlling factors, and few have dealt with the integrated effects of climate, vegetation, and soil substrate availability on soil microbial communities and functions among different forests. In this study, we used phospholipid-derived fatty acid (PLFA) analysis to investigate soil microbial community structure and extracellular enzymatic activities to evaluate the functional potential of soil microbes of different types of forests in three different climatic zones along the north-south transect in eastern China (NSTEC). Both climate and forest type had significant effects on soil enzyme activities and microbial communities with considerable interactive effects. Except for soil acid phosphatase (AP), the other three enzyme activities were much higher in the warm temperate zone than in the temperate and the subtropical climate zones. The soil total PLFAs and bacteria were much higher in the temperate zone than in the warm temperate and the subtropical zones. The soil β-glucosidase (BG) and N-acetylglucosaminidase (NAG) activities were highest in the coniferous forest. Except for the soil fungi and fungi-bacteria (F/B), the different groups of microbial PLFAs were much higher in the conifer broad-leaved mixed forests than in the coniferous forests and the broad-leaved forests. In general, soil enzyme activities and microbial PLFAs were higher in primary forests than in secondary forests in temperate and warm temperate regions. In the subtropical region, soil enzyme activities were lower in the primary forests than in the secondary forests and microbial PLFAs did not differ significantly between primary and secondary forests. Different compositions of the tree species may cause variations in soil microbial communities and enzyme activities. Our results

  13. Seasonal variation and controlling factors of soil carbon effluxes in six vegetation types in southeast of Sweden

    International Nuclear Information System (INIS)

    Tagesson, Torbern

    2007-11-01

    Soil carbon effluxes of a pine stand, a spruce stand, a lichen rock, two oak stands and a meadow in the Laxemar investigation area in south-eastern Sweden (57 deg 5 N, 16 deg 7 E) have been measured with the closed chamber technique at 14 occasions between 23 of March 2004 and 10th of March 2005. Soil temperature at 10 cm depth, air temperature, soil moisture and photosynthetically active radiation (PAR) were also measured. Exponential regressions with soil respiration against air and soil temperature were used to estimate soil respiration between 15th of March 2004 and 14th of March 2005. A light response curve with Gross Primary Production (GPP) against PAR and a cubic regression with GPP against air temperature were used for modelling GPP in meadow for the growing season, 15th of March to 31st of October 2004. The exponential regressions with soil respiration against air and soil temperature explained on average 30.6% and 47.6% of the variation, respectively. Soil moisture had a linear limiting effect on soil respiration for all ecosystems but spruce, where soil moisture was the limiting factor above a threshold value of about 50%vol. In the forest ecosystems, GPP of the ground vegetation were not reducing soil carbon effluxes, while in meadow it was. In meadow, the light response curve with GPP against PAR explained 32.7% of the variation in GPP while the cubic regression against air temperature explained 33.9%. No significant effect of soil moisture on GPP was detected. The exponential regression equations with air and soil temperature against soil respiration could be used to temporally extrapolate the occasional field measurements. The light response curve with GPP against PAR and the cubic regression with GPP against air temperature could also be used for temporal extrapolation. From the modelled soil respiration, annual soil respiration for the ecosystems in Laxemar, during 15th of March 2004 to 14th of March 2005, were estimated to be between 0.56 and 1

  14. Factors affecting vertical distribution of Fukushima accident-derived radiocesium in soil under different land-use conditions

    International Nuclear Information System (INIS)

    Koarashi, Jun; Atarashi-Andoh, Mariko; Matsunaga, Takeshi; Sato, Tsutomu; Nagao, Seiya; Nagai, Haruyasu

    2012-01-01

    The Fukushima Dai-ichi nuclear power plant accident in Japan, triggered by a big earthquake and the resulting tsunami on 11 March 2011, caused a substantial release of radiocesium ( 137 Cs and 134 Cs) and a subsequent contamination of soils in a range of terrestrial ecosystems. Identifying factors and processes affecting radiocesium retention in these soils is essential to predict how the deposited radiocesium will migrate through the soil profile and to other biological components. We investigated vertical distributions of radiocesium and physicochemical properties in soils (to 20 cm depth) at 15 locations under different land-use types (croplands, grasslands, and forests) within a 2 km × 2 km mesh area in Fukushima city. The total 137 Cs inventory deposited onto and into soil was similar (58.4 ± 9.6 kBq m −2 ) between the three different land-use types. However, aboveground litter layer at the forest sites and herbaceous vegetation at the non-forested sites contributed differently to the total 137 Cs inventory. At the forest sites, 50–91% of the total inventory was observed in the litter layer. The aboveground vegetation contribution was in contrast smaller ( 137 Cs in mineral soil layers; 137 Cs penetrated deeper in the forest soil profiles than in the non-forested soil profiles. We quantified 137 Cs retention at surface soil layers, and showed that higher 137 Cs retention can be explained in part by larger amounts of silt- and clay-sized particles in the layers. More importantly, the 137 Cs retention highly and negatively correlated with soil organic carbon content divided by clay content across all land-use types. The results suggest that organic matter inhibits strong adsorption of 137 Cs on clay minerals in surface soil layers, and as a result affects the vertical distribution and thus the mobility of 137 Cs in soil, particularly in the forest ecosystems. - Highlights: ► Vertical distribution of radiocesium was investigated for 15 soils. ► Forest

  15. Soil-transmitted helminths in southern highland Rwanda: associated factors and effectiveness of school-based preventive chemotherapy.

    Science.gov (United States)

    Staudacher, Olga; Heimer, Jakob; Steiner, Florian; Kayonga, Yvette; Havugimana, Jean M; Ignatius, Ralf; Musemakweri, Andre; Ngabo, Fidele; Harms, Gundel; Gahutu, Jean-Bosco; Mockenhaupt, Frank P

    2014-07-01

    Preventive chemotherapy of schoolchildren against soil-transmitted helminths (STHs) is widely implemented in Rwanda. However, data on its actual efficacy are lacking. We assessed prevalence, associated factors and manifestation of STH infection among schoolchildren in southern highland Rwanda as well as cure and reinfection rates. Six hundred and twenty-two children (rural, 301; urban, 321) were included preceding the administration of a single dose of 500 mg mebendazole. Before treatment, and after 2 and 15 weeks, STH infection was determined by Kato-Katz smears and by PCR assays for Ascaris lumbricoides. Clinical and anthropometric data, socio-economic status and factors potentially associated with STH infection were assessed. Soil-transmitted helminth (STH) infection was present in 38% of rural and in 13% of urban schoolchildren. Ascaris lumbricoides accounted for 96% of infections. Of these, one-third was detected by PCR exclusively. Factors associated with STH infection differed greatly between rural and urban children. Likewise, STH infection was associated with stunting and anaemia only among urban children. The cure rate after 2 weeks was 92%. Among eight non-cleared A. lumbricoides infections, seven were submicroscopic. Reinfection within 3 months occurred in 7%, but the rate was higher among rural children, and with initially present infection, particularly at comparatively high intensity. The rural-urban difference in factors associated with STH infection and in reinfection rates highlights the need for targeted interventions to reduce transmission. PCR assays may help in detecting low-level infections persisting after treatment. In southern Rwanda, mebendazole is highly effective against the STH infections predominated by A. lumbricoides. © 2014 John Wiley & Sons Ltd.

  16. Worldwide organic soil carbon and nitrogen data

    Energy Technology Data Exchange (ETDEWEB)

    Zinke, P.J.; Stangenberger, A.G. [Univ. of California, Berkeley, CA (United States). Dept. of Forestry and Resource Management; Post, W.M.; Emanual, W.R.; Olson, J.S. [Oak Ridge National Lab., TN (United States)

    1986-09-01

    The objective of the research presented in this package was to identify data that could be used to estimate the size of the soil organic carbon pool under relatively undisturbed soil conditions. A subset of the data can be used to estimate amounts of soil carbon storage at equilibrium with natural soil-forming factors. The magnitude of soil properties so defined is a resulting nonequilibrium values for carbon storage. Variation in these values is due to differences in local and geographic soil-forming factors. Therefore, information is included on location, soil nitrogen content, climate, and vegetation along with carbon density and variation.

  17. Factors causing spatial heterogeneity in soil properties, plant cover, and soil fauna in a non-reclaimed post-mining site

    Czech Academy of Sciences Publication Activity Database

    Frouz, J.; Kalčík, Jiří; Velichová, V.

    2011-01-01

    Roč. 37, č. 11 (2011), s. 1910-1913 ISSN 0925-8574 R&D Projects: GA MŠk 2B08023 Institutional research plan: CEZ:AV0Z60660521 Keywords : soil chemistry * vegetation * invertebrates Subject RIV: EH - Ecology, Behaviour Impact factor: 3.106, year: 2011

  18. Survey of Associations among Soil Properties and Climatic Factors on Weed Distribution in Wheat (Triticum aestivum L. in Kermanshah Province

    Directory of Open Access Journals (Sweden)

    Mozhgan veisi

    2016-11-01

    of different districts by rows. Data on weed communities and environmental factors of all districts were analyzed through with ordination methods like canonical correspondence analysis (CCA and weed species distribution and environmental factors displayed in ordination diagrams. These ordination methods were done with mean density of 29 abundant weed species for CCA using CANOCO (Version 4.5. Ordination plots were produced for both sampling sites and weed species associated with environmental factors. For CCA, we used site elevation, humidity for 10 years period, daily raining for a 10 years period. Soil characteristic included calcium, phosphor, potassium, nitrogen, sodium, magnesium, pH were determined. Sand, clay and silt in soils were measured and elevation of each field was gained by GPS. Results and discussion 162 weed species belonging to 33 plant families were identified in these fields. Multivariate analyses with canonical correspondence analysis (CCA showed that changes in the weed species distribution were due to soil characters (pH, Calcium, Magnesium, Phosphorus, Nitrogen, Sodium, Potassium, silt percent, clay and loam in soil tissue, cation exchange capacity, EC and environmental conditions during former years. The first and second RDA axes described 64% of variations in the weed populations affected by climatic factors. Winter wild oat (Avena ludoviciana L., ryegrass (Lolium rigidum Gaud., wild mustard (Sinapis arvensis L. and canary seed (Phalaris brachystacys Link. in areas of high temperature and low altitude, had a wide distribution. High evaporation increased wild barely (Hordeum spontaneum C. Koch., Corn cleavers (Galium tricornutum Dandy. and Vetch (Vicia assyriaca Boiss. density during last decade. Where the soil nitrogen and phosphorus rates were high, Wild barely (Hordeum spontaneum C. Koch. density was found frequently in wheat fields of Kermanshah. In the wheat fields of Kermanshah, Bindweed (Convolvulus arvensis L. and wild safflower

  19. Excitation and charge transfer in He/sup +/ + H collisions. A molecular approach including two-electron translation factors

    Energy Technology Data Exchange (ETDEWEB)

    Errea, L.F.; Mendez, L.; Riera, A.

    1983-06-01

    In a previous paper we have pointed out that the common-translation-factor (CTF) method is the only one which, at present, and within the framework of the molecular model of atomic collisions, can be shown to be both convergent and computationally fast, even for many-electron systems. In this Communication we check that this second statement is correct, presenting, for the first time, a molecular calculation involving two-electron translation factors, for He/sup +/ + H collisions. A careful study of the sensitivity of the calculated cross sections to the choice of the CTF is performed, and conclusions on that sensitivity are drawn, for several types of processes.

  20. Excitation and charge transfer in He+ + H collisions. A molecular approach including two-electron translation factors

    International Nuclear Information System (INIS)

    Errea, L.F.; Mendez, L.; Riera, A.

    1983-01-01

    In a previous paper we have pointed out that the common-translation-factor (CTF) method is the only one which, at present, and within the framework of the molecular model of atomic collisions, can be shown to be both convergent and computationally fast, even for many-electron systems. In this Communication we check that this second statement is correct, presenting, for the first time, a molecular calculation involving two-electron translation factors, for He + + H collisions. A careful study of the sensitivity of the calculated cross sections to the choice of the CTF is performed, and conclusions on that sensitivity are drawn, for several types of processes

  1. What is Soil?

    Science.gov (United States)

    It! What is Soil? Chip Off the Old Block Soil Forming Factors Matters of Life and Death Underneath It All Wise Choices A World of Soils Soil? 2 The Skin of the Earth 3 Soil Ingredients 4 Soil Recipes 5 CLORPT for Short >> What Is Soil? Soils Make Life Plants grow in and from

  2. Reduction of risk factors for nuclear power plants due to personnel psychological data, including attitude, morale and motivation

    International Nuclear Information System (INIS)

    Abramova, V.N.

    1997-01-01

    The possibilities of reduction of risk factors for personnel activity and performance due to attitudes, motivation and moral are presented. Methodology and experience in psychology, sociopsychology, psychophisiology and sociology mistake sources are discussed. Authorization to job, stages of estimating occupational fitness and modules system of personnel psychological and sociopsychological training probabilistic are explained. (author). 3 figs, 1 tab

  3. [Investigation on prevalence of soil-transmitted nematode infections and influencing factors for children in southwest areas of China].

    Science.gov (United States)

    Wang, Xiao-Bing; Wang, Guo-Fei; Zhang, Lin-Xiu; Luo, Ren-Fu; Tian, Hong-Chun; Tang, Li-Na; Wang, Ju-Jun; Medina, Alexis; Wise, Paul; Rozelle, Scott

    2012-06-01

    To understand the infection status and main risk factors of soil-transmitted nematodes in southwest China so as to provide the evidence for making the control programs for soil-transmitted nematodiasis. The prevalence of soil-transmitted nematode infections was determined by Kato-Katz technique and influencing factors were surveyed by using a standardized questionnaire, and in part of the children, the examination of Enterobius vermicularis eggs was performed by using the cellophane swab method. The relationship between soil-transmitted nematode infections and influencing factors was analyzed by the multiple probit estimated method. A total of 1 707 children were examined, with a soil-transmitted nematode infection rate of 22.2%, the crowd infection rates ofAscaris lumbricoides, hookworm, and Trichuris trichiura were 16.0%, 3.8% and 6.6% respectively and 495 children were examined on Enterobius vermicularis eggs, with the infection rate of 5.1%. The results of probit estimated analysis suggested that the effects of 4 factors on soil-transmitted nematode infections were significant (all P values were less than 0.05), namely the number of sib, educational level of mother, drinking unboiled water and raising livestock and poultry. Among the factors above, the educational level of mother could reduce the probability of infection (ME = -0.074), while the number of sib, drinking unboiled water and raising livestock and poultry could increase the probability of the infections (with ME of 0.028, -0.112 and 0.080, respectively). Soil-transmitted nematode infection rates are still in a high level for children in southwest poor areas of China, with Ascaris lumbricoides as a priority. The changes of children's bad health habits, raising livestock and poultry habits, and implementing the health education about parasitic diseases in mothers would be of great significance for the prevention and control of soil-transmitted nematodiasis.

  4. An analysis of domestic experimental results for soil-to-crops transfer factors of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Jun, In; Choi, Young Ho; Keum, Dong Kwon; Kang, Hee Seok; Lee, Han Soo; Lee, Chang Woo [KAERI, Daejeon (Korea, Republic of)

    2006-12-15

    For more realistic assessment of Korean food chain radiation doses due to the operation of nuclear facilities, it is required to use domestically produced data for radionuclide transfer parameters in crop plants. This paper analyzed results of last about 10 year's studies on radionuclide transfer parameters in major crop plants by the Korean Atomic Energy Research Institute, comparing with the published international data, and consequently suggested the proper parameters to use. The trends of transfer parameter shows normal distributions if we have a lot of experimental data, but some radionuclides showed enormous variations with the environment of experimental, crops and soils. These transfer factors can be used to assess realistic radiation doses or to predict the doses in crops for normal operation or accidental release. Some kinds of parameter can be produced as conservatives or fragmentary results because soil-to-plant transfer factors were measured through greenhouse experiments which sometimes showed improper field situations. But these parameters mentioned in this paper can be representative of the status of Korean food chain than that of foreign country.

  5. An analysis of domestic experimental results for soil-to-crops transfer factors of radionuclides

    International Nuclear Information System (INIS)

    Jun, In; Choi, Young Ho; Keum, Dong Kwon; Kang, Hee Seok; Lee, Han Soo; Lee, Chang Woo

    2006-01-01

    For more realistic assessment of Korean food chain radiation doses due to the operation of nuclear facilities, it is required to use domestically produced data for radionuclide transfer parameters in crop plants. This paper analyzed results of last about 10 year's studies on radionuclide transfer parameters in major crop plants by the Korean Atomic Energy Research Institute, comparing with the published international data, and consequently suggested the proper parameters to use. The trends of transfer parameter shows normal distributions if we have a lot of experimental data, but some radionuclides showed enormous variations with the environment of experimental, crops and soils. These transfer factors can be used to assess realistic radiation doses or to predict the doses in crops for normal operation or accidental release. Some kinds of parameter can be produced as conservatives or fragmentary results because soil-to-plant transfer factors were measured through greenhouse experiments which sometimes showed improper field situations. But these parameters mentioned in this paper can be representative of the status of Korean food chain than that of foreign country

  6. Biological Soil Crusts of Arctic Svalbard—Water Availability as Potential Controlling Factor for Microalgal Biodiversity

    Directory of Open Access Journals (Sweden)

    Nadine Borchhardt

    2017-08-01

    Full Text Available In the present study the biodiversity of biological soil crusts (BSCs formed by phototrophic organisms were investigated on Arctic Svalbard (Norway. These communities exert several important ecological functions and constitute a significant part of vegetation at high latitudes. Non-diatom eukaryotic microalgal species of BSCs from 20 sampling stations around Ny-Ålesund and Longyearbyen were identified by morphology using light microscopy, and the results revealed a high species richness with 102 species in total. 67 taxa belonged to Chlorophyta (31 Chlorophyceae and 36 Trebouxiophyceae, 13 species were Streptophyta (11 Klebsormidiophyceae and two Zygnematophyceae and 22 species were Ochrophyta (two Eustigmatophyceae and 20 Xanthophyceae. Surprisingly, Klebsormidium strains belonging to clade G (Streptophyta, which were so far described from Southern Africa, could be determined at 5 sampling stations. Furthermore, comparative analyses of Arctic and Antarctic BSCs were undertaken to outline differences in species composition. In addition, a pedological analysis of BSC samples included C, N, S, TP (total phosphorus, and pH measurements to investigate the influence of soil properties on species composition. No significant correlation with these chemical soil parameters was confirmed but the results indicated that pH might affect the BSCs. In addition, a statistically significant influence of precipitation on species composition was determined. Consequently, water availability was identified as one key driver for BSC biodiversity in Arctic regions.

  7. Biological Soil Crusts of Arctic Svalbard-Water Availability as Potential Controlling Factor for Microalgal Biodiversity.

    Science.gov (United States)

    Borchhardt, Nadine; Baum, Christel; Mikhailyuk, Tatiana; Karsten, Ulf

    2017-01-01

    In the present study the biodiversity of biological soil crusts (BSCs) formed by phototrophic organisms were investigated on Arctic Svalbard (Norway). These communities exert several important ecological functions and constitute a significant part of vegetation at high latitudes. Non-diatom eukaryotic microalgal species of BSCs from 20 sampling stations around Ny-Ålesund and Longyearbyen were identified by morphology using light microscopy, and the results revealed a high species richness with 102 species in total. 67 taxa belonged to Chlorophyta (31 Chlorophyceae and 36 Trebouxiophyceae), 13 species were Streptophyta (11 Klebsormidiophyceae and two Zygnematophyceae) and 22 species were Ochrophyta (two Eustigmatophyceae and 20 Xanthophyceae). Surprisingly, Klebsormidium strains belonging to clade G (Streptophyta), which were so far described from Southern Africa, could be determined at 5 sampling stations. Furthermore, comparative analyses of Arctic and Antarctic BSCs were undertaken to outline differences in species composition. In addition, a pedological analysis of BSC samples included C, N, S, TP (total phosphorus), and pH measurements to investigate the influence of soil properties on species composition. No significant correlation with these chemical soil parameters was confirmed but the results indicated that pH might affect the BSCs. In addition, a statistically significant influence of precipitation on species composition was determined. Consequently, water availability was identified as one key driver for BSC biodiversity in Arctic regions.

  8. Developing relations between soil erodibilty factors in two different soil erosion prediction models (USLE/RUSLE and wWEPP) and fludization bed technique for mechanical soil cohesion

    Science.gov (United States)

    Soil erosion models are valuable analysis tools that scientists and engineers use to examine observed data sets and predict the effects of possible future soil loss. In the area of water erosion, a variety of modeling technologies are available, ranging from solely qualitative models, to merely quan...

  9. Analysis of factors controlling soil phosphorus loss with surface runoff in Huihe National Nature Reserve by principal component and path analysis methods.

    Science.gov (United States)

    He, Jing; Su, Derong; Lv, Shihai; Diao, Zhaoyan; Bu, He; Wo, Qiang

    2018-01-01

    Phosphorus (P) loss with surface runoff accounts for the P input to and acceleration of eutrophication of the freshwater. Many studies have focused on factors affecting P loss with surface runoff from soils, but rarely on the relationship among these factors. In the present study, rainfall simulation on P loss with surface runoff was conducted in Huihe National Nature Reserve, in Hulunbeier grassland, China, and the relationships between P loss with surface runoff, soil properties, and rainfall conditions were examined. Principal component analysis and path analysis were used to analyze the direct and indirect effects on P loss with surface runoff. The results showed that P loss with surface runoff was closely correlated with soil electrical conductivity, soil pH, soil Olsen P, soil total nitrogen (TN), soil total phosphorus (TP), and soil organic carbon (SOC). The main driving factors which influenced P loss with surface runoff were soil TN, soil pH, soil Olsen P, and soil water content. Path analysis and determination coefficient analysis indicated that the standard multiple regression equation for P loss with surface runoff and each main factor was Y = 7.429 - 0.439 soil TN - 6.834 soil pH + 1.721 soil Olsen-P + 0.183 soil water content (r = 0.487, p runoff. The effect of physical and chemical properties of undisturbed soils on P loss with surface runoff was discussed, and the soil water content and soil Olsen P were strongly positive influences on the P loss with surface runoff.

  10. Particle size distribution in soils and marine sediments by laser diffraction using Malvern Mastersizer 2000—method uncertainty including the effect of hydrogen peroxide pretreatment

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Keck, Hannes; Andersen, Thorbjørn Joest

    2018-01-01

    with less than 1% C and some marine sediments. Materials and methods: The method uncertainty for particle size analysis by the laser diffraction method using or not using H2O2 pretreatment followed by 2 min ultrasound and 1-mm sieving was determined for two soil samples and two aquatic sediments......Purpose: Methods for particle size distribution (PSD) determination by laser diffraction are not standardized and differ between disciplines and sectors. The effect of H2O2 pretreatment before a sonication treatment in laser diffraction analysis of soils and marine sediments was examined on soils...... pretreatment on the PSD was small and not significant. The standard deviation (std) in particle size fractions increased with particle size. PSDs and std for some samples were presented for future reference. Similar to other studies, the content of clay and silt (by sieving/hydrometer, SHM) was lower...

  11. Vegetation type and the presence of ash as factors in the evolution of soil water repellency after a forest fire

    Directory of Open Access Journals (Sweden)

    P. Jiménez-Pinilla

    2013-05-01

    Full Text Available After wildfires, burning may induce the occurrence of soil water repellency. Soil water repellency may vary in space and time in function of vegetation, the presence of ash and soil moisture. This study analyzes the evolution of fire-induced soil water repellency in function of these factors, and proposes measures to promote the restoration of fire-affected soils. Burnt and unburnt (control soil plots under pine and shrub from a recently burned area (Gorga, Alicante, SE Spain were established. Three treatments were applied: in some of the plots, the original ash layer was kept on the ground; in a second group, the ash layer was removed for simulating the effects of erosion; finally, in a third group, percolating irrigation was conducted to simulate a possible good input of water into the soil profile after burning, that could occur if the first rains were with high quantity but low intensity. During the dry season, soil moisture content was significantly lower in burned plots due to fire-induced water repellency and reduced vegetation cover. During the wet season, soil moisture decreased in the control unburnt plots due to direct evaporation of water intercepted by vegetation and consumption by roots. Fire increased soil water repellency only in plots under pine. Water repellency decreased during the wet season, disappearing in January and reappearing after declining rainfalls. This baseline recovery of soil water repellency was lower where ash removal was simulated. In unburned plots, seasonal fluctuations were less important. In general, ash removal promotes a rapid reduction of water repellency, since it can induce washing of hydrophobic compounds. Irrigation performed immediately after the fire also contributed to decreased water repellency.

  12. Relative influence of soil chemistry and topography on soil available micronutrients by structural equation modeling

    OpenAIRE

    Zhu, Hongfen; Zhao, Ying; Nan, Feng; Duan, Yonghong; Bi, Rutian

    2016-01-01

    Soil chemical and topographic properties are two important factors influencing available micronutrient distribution of soil in the horizontal dimension. The objective of this study was to explore the relative influence of soil chemistry (including soil pH, soil organic matter, total nitrogen, available phosphorus, and available potassium) and topography (including elevation, slope, aspect, and wetness index) on the availability of micronutrients (Fe, Mn, Cu, Zn, and B) using structural equati...

  13. Health-related quality of life and hand eczema--a comparison of two instruments, including factor analysis.

    Science.gov (United States)

    Wallenhammar, Lena-Marie; Nyfjäll, Mats; Lindberg, Magnus; Meding, Birgitta

    2004-06-01

    Hand eczema is a disease of long duration, affecting the individual and society. The purpose of this study of 100 patients (51 females and 49 males) at an occupational dermatology clinic was to investigate whether the generic questionnaire Short Form-36 (SF-36), and the dermatology-specific Dermatology Life Quality Index (DLQI) are appropriate for assessing health-related quality of life (HRQL) in patients with hand eczema, and whether gender differences in HRQL could be detected. HRQL was affected by hand eczema, measured with both SF-36 and DLQI. The SF-36 showed more impaired HRQL for females than for males, in the mental health dimension, whereas no gender-related differences were detected with the DLQI. To compare the instruments we used factor analysis, with a polychoric correlation matrix as input, thus taking the ordinal aspect of the data into account. There was a high correlation between the instruments for physical health, but lower for mental health. In this context our interpretation of the factor analysis is that the SF-36 measures mental health better than the DLQI. The SF-36 therefore appears suitable for use in future studies for measuring HRQL, and gender differences in HRQL, in persons with reported hand eczema.

  14. 40 CFR 273.81 - Factors for petitions to include other wastes under 40 CFR part 273.

    Science.gov (United States)

    2010-07-01

    ... AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Petitions To Include... generic name to identify the waste category (e.g., batteries), the definition of universal waste in § 260..., and specific management standards proposed or referenced by the petitioner (e.g., waste management...

  15. Using scaling factors for evaluating spatial and temporal variability of soil hydraulic properties within one elevation transect

    Science.gov (United States)

    Nikodem, Antonín; Kodešová, Radka; Jakšík, Ondřej; Fér, Miroslav; Klement, Aleš

    2016-04-01

    This study was carried out in Southern Moravia, in the Czech Republic. The original soil unit in the wider area is a Haplic Chernozem developed on loess. The intensive agricultural exploitation in combination with terrain morphology has resulted in a highly diversified soil spatial pattern. Nowadays the original soil unit is preserved only on top of relatively flat parts, and is gradually transformed by water erosion up to Regosols on the steepest slopes, while colluvial soils are formed in terrain depressions and at toe slopes due to sedimentation of previously eroded material. Soils within this area has been intensively investigated during the last several years (e.g. Jakšík et al., 2015; Vašát et al., 2014, 2015a,b). Soil sampling (disturbed and undisturbed 100-cm3 soil samples) was performed at 5 points of one elevation transect in November 2010 (after wheat sowing) and August 2011 (after wheat harvest). Disturbed soil samples were used to determine basic soil properties (grain size distribution and organic carbon content etc.). Undisturbed soil samples were used to determine the soil water retention curves and the hydraulic conductivity functions using the multiple outflow tests in Tempe cells and a numerical inversion with HYDRUS 1-D. Scaling factors (alpha-h for pressure head, alpha-theta for soil water contents and alpha-k for hydraulic conductivities) were used here to express soil hydraulic properties variability. Evaluated scaling factors reflected position within the elevation transect as well as time of soil sampling. In general large values of alpha-h, lower values of alpha-k and similar values of alpha-theta were obtained in 2010 in comparison to values obtained in 2011, which indicates development of soil structure during the vegetation season. Jakšík, O., Kodešová, R., Kubiš, A., Stehlíková, I., Drábek, O., Kapička, A. (2015): Soil aggregate stability within morphologically diverse areas. Catena, 127, 287-299. Vašát, R., Kode

  16. Factors associated with a clinician's offer of screening HIV-positive patients for sexually transmitted infections, including syphilis.

    Science.gov (United States)

    Heller, R; Fernando, I; MacDougall, M

    2011-06-01

    This retrospective study assessed whether Quality Improvement Scotland national standards for the sexual health care offered to HIV-positive individuals are being met by the Edinburgh genitourinary (GU) medicine clinic; specifically whether HIV-positive patients are offered: (a) sexually transmitted infection (STI) screening annually and (b) syphilis testing six-monthly. The study also reviewed what factors were associated with a clinician's offer of STI screening and syphilis testing. Of the 509 patients seen within the study period, case notes documented that 64% were offered STI screens, and 69% were offered syphilis testing, results consistent with audits of services elsewhere. Sexual orientation (P offer of STI screening, while gender (P offer of syphilis testing. Our results suggest that one explanation for clinicians failing to offer STI screens and syphilis serology testing is their (implicit) risk assessment that STI testing is not required in individual patients.

  17. A review on early gut maturation and colonization in pigs, including biological and dietary factors affecting gut homeostasis

    DEFF Research Database (Denmark)

    Everaert, Nadia; Van Cruchten, Steven; Weström, Björn

    2017-01-01

    During the prenatal, neonatal and post-weaning periods, the mammalian gastrointestinal tract undergoes various morphological and physiological changes alongside with an expansion of the immune system and microbial ecosystem. This review focuses on the time period before weaning and summarizes...... in digestive function coincides with development in both the adaptive and innate immune system. This secures a balanced immune response to the ingested milk-derived macromolecules, and colonizing bacteria. Husbandry and dietary interventions in early life appear to affect the development of multiple components...... and immunological maturation, as influenced by early microbial colonization and ingestion of dietary factors, is of utmost importance to identify management and feeding strategies to optimize intestinal health. We discuss some possible implications related to intrauterine growth restriction, and preterm delivery...

  18. Diel hysteresis between soil respiration and soil temperature in a biological soil crust covered desert ecosystem.

    Science.gov (United States)

    Guan, Chao; Li, Xinrong; Zhang, Peng; Chen, Yongle

    2018-01-01

    Soil respiration induced by biological soil crusts (BSCs) is an important process in the carbon (C) cycle in arid and semi-arid ecosystems, where vascular plants are restricted by the harsh environment, particularly the limited soil moisture. However, the interaction between temperature and soil respiration remains uncertain because of the number of factors that control soil respiration, including temperature and soil moisture, especially in BSC-dominated areas. In this study, the soil respiration in moss-dominated crusts and lichen-dominated crusts was continuously measured using an automated soil respiration system over a one-year period from November 2015 to October 2016 in the Shapotou region of the Tengger Desert, northern China. The results indicated that over daily cycles, the half-hourly soil respiration rates in both types of BSC-covered areas were commonly related to the soil temperature. The observed diel hysteresis between the half-hourly soil respiration rates and soil temperature in the BSC-covered areas was limited by nonlinearity loops with semielliptical shapes, and soil temperature often peaked later than the half-hourly soil respiration rates in the BSC-covered areas. The average lag times between the half-hourly soil respiration rates and soil temperature for both types of BSC-covered areas were two hours over the diel cycles, and they were negatively and linearly related to the volumetric soil water content. Our results highlight the diel hysteresis phenomenon that occurs between soil respiration rates and soil temperatures in BSC-covered areas and the negative response of this phenomenon to soil moisture, which may influence total C budget evaluations. Therefore, the interactive effects of soil temperature and moisture on soil respiration in BSC-covered areas should be considered in global carbon cycle models of desert ecosystems.

  19. Key biogeochemical factors affecting soil carbon storage in Posidonia meadows

    KAUST Repository

    Serrano, Oscar; Ricart, Aurora M.; Lavery, Paul S.; Mateo, Miguel Angel; Arias-Ortiz, Ariane; Masque, Pere; Rozaimi, Mohammad; Steven, Andy; Duarte, Carlos M.

    2016-01-01

    Biotic and abiotic factors influence the accumulation of organic carbon (C-org) in seagrass ecosystems. We surveyed Posidonia sinuosa meadows growing in different water depths to assess the variability in the sources, stocks and accumulation rates of Corg. We show that over the last 500 years, P. sinuosa meadows closer to the upper limit of distribution (at 2-4 m depth) accumulated 3- to 4-fold higher C-org stocks (averaging 6.3 kg C-org m(-2) at 3- to 4-fold higher rates (12.8 gC(org) m(-2) yr(-1) ) compared to meadows closer to the deep limits of distribution (at 6-8 m depth; 1.8 kg C-org m(-2) and 3.6 g C-org m(-2) yr(-1) . In shallower meadows, C-org stocks were mostly derived from seagrass detritus (88% in average) compared to meadows closer to the deep limit of distribution (45% on average). In addition, soil accumulation rates and fine-grained sediment content (< 0.125 mm) in shallower meadows (2.0 mm yr(-1) and 9 %, respectively) were approximately 2-fold higher than in deeper meadows (1.2 mm yr(-1) and 5 %, respectively). The C-org stocks and accumulation rates accumulated over the last 500 years in bare sediments (0.6 kg C-org m(-2) and 1.2 g C-org m(-2) yr(-1)were 3- to 11-fold lower than in P. sinuosa meadows, while fine-grained sediment content (1 %) and seagrass detritus contribution to the Corg pool (20 %) were 8- and 3-fold lower than in Posidonia meadows, respectively. The patterns found support the hypothesis that Corg storage in seagrass soils is influenced by interactions of biological (e.g., meadow productivity, cover and density), chemical (e.g., recalcitrance of Corg stocks) and physical (e.g., hydrodynamic energy and soil accumulation rates) factors within the meadow. We conclude that there is a need to improve global estimates of seagrass carbon storage accounting for biogeochemical factors driving variability within habitats.

  20. Drivers of soil organic matter vulnerability to climate change, Part II: RothC modelling of carbon dynamics including radiocarbon data

    Science.gov (United States)

    Studer, Mirjam S.; Abiven, Samuel; González Domínguez, Beatriz R.; Hagedorn, Frank; Reisser, Moritz; Walthert, Lorenz; Zimmermann, Stephan; Niklaus, Pascal A.

    2016-04-01

    It is still largely unknown what drives the vulnerability of soil organic carbon (SOC) stocks to climate change, i.e. the likelihood of a soil to loose its SOC along with the change in environmental conditions. Our objective is to assess the SOC vulnerability of Swiss forest soils and identify its potential drivers: climate (temperature, soil moisture), soil (clay content, pH) and landscape (slope, aspect) properties. Fifty-four sites were selected for balanced spatial and driver magnitudes distribution. We measured the SOC characteristics (content and radiocarbon) and studied the C decomposition by laboratory soil incubations (details in Part I, abstract by B. González Domínguez). In order to assess the current SOC pool distribution and its radiocarbon signatures, we extended the Rothamsted Carbon (RothC) model with radiocarbon (14C) isotope modelling (RothCiso). The RothC model distinguishes four active SOC pools, decomposable and resistant plant material, microbial biomass and humified organic matter, and an inert SOC pool (Jenkinson 1990). The active pools are decomposed and mineralized to CO2 by first order kinetics. The RothCiso assigns all pools a 14C signature, based on the atmospheric 14C concentrations of the past century (plant C inputs) and their turnover. Currently we constrain the model with 14C signatures measured on the 54 fresh and their corresponding archived bulk soil samples, taken 12-24 years before. We were able to reproduce the measured radiocarbon concentrations of the SOC with the RothCiso and first results indicate, that the assumption of an inert SOC pool, that is radiocarbon dead, is not appropriate. In a second step we will compare the SOC mean residence time assessed by the two methodological approaches - incubation (C efflux based) and modelling (C stock based) - and relate it to the environmental drivers mentioned above. With the combination of the two methodological approaches and 14C analysis we hope to gain more insights into

  1. Monte Carlo calculation of dose rate conversion factors for external exposure to photon emitters in soil

    CERN Document Server

    Clouvas, A; Antonopoulos-Domis, M; Silva, J

    2000-01-01

    The dose rate conversion factors D/sub CF/ (absorbed dose rate in air per unit activity per unit of soil mass, nGy h/sup -1/ per Bq kg/sup -1/) are calculated 1 m above ground for photon emitters of natural radionuclides uniformly distributed in the soil. Three Monte Carlo codes are used: 1) The MCNP code of Los Alamos; 2) The GEANT code of CERN; and 3) a Monte Carlo code developed in the Nuclear Technology Laboratory of the Aristotle University of Thessaloniki. The accuracy of the Monte Carlo results is tested by the comparison of the unscattered flux obtained by the three Monte Carlo codes with an independent straightforward calculation. All codes and particularly the MCNP calculate accurately the absorbed dose rate in air due to the unscattered radiation. For the total radiation (unscattered plus scattered) the D/sub CF/ values calculated from the three codes are in very good agreement between them. The comparison between these results and the results deduced previously by other authors indicates a good ag...

  2. Reserve, thin form-factor, hypochlorite-based cells for powering portable systems: Manufacture (including MEMS processes), performance and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas-Valencia, Andres M.; Langebrake, Larry [Center for Ocean Technology, University of South Florida, 140 Seventh Ave. S., St. Petersburg, FL (United States); Biver, Carl J. [Center for Ocean Technology, University of South Florida, 140 Seventh Ave. S., St. Petersburg, FL (United States); Department of Chemical Engineering, University of South Florida, 4202 E. Fowler Ave. Tampa, FL (United States)

    2007-03-30

    This work focuses on fabrication routes and performance evaluation of thin form-factors, reserve cells, as a powering alternative for expendable and/or remotely operated systems. The catalytic decomposition of sodium hypochlorite solutions is revisited herein with two cost-effective anodes: zinc and aluminum. Aluminum, even though the most expensive of the utilized anodes, constituted cells with double the energy content (up to 55 Wh kg{sup -1}) than those fabricated with zinc. Even though the hypochlorite concentration in the solution limits the cells' operational life, attractive performances (1.0 V with a current of 10 mA) for the manufactured cells are obtained. It is shown that micro fabrication processes, allowing for close electrodes interspacing, provided high faradic and columbic efficiencies of up to 70 and 100%, respectively. Obtained specific energies (50-120 Wh kg{sup -1}) are in the same order of magnitude than batteries currently used for powering deployable systems. Experimental results show that a simple model that linearly relates over potentials and the electrical load, adequately describe all the cell designs. A mathematical model based on a kinetic-mechanistic scheme that relates the current output as a function of time agrees fairly well with results obtained activating cells with various concentrations of NaOCl solutions. (author)

  3. Factors for Microbial Carbon Sources in Organic and Mineral Soils from Eastern United States Deciduous Forests

    Energy Technology Data Exchange (ETDEWEB)

    Stitt, Caroline R. [Mills College, Oakland, CA (United States)

    2013-09-16

    Forest soils represent a large portion of global terrestrial carbon; however, which soil carbon sources are used by soil microbes and respired as carbon dioxide (CO2) is not well known. This study will focus on characterizing microbial carbon sources from organic and mineral soils from four eastern United States deciduous forests using a unique radiocarbon (14C) tracer. Results from the dark incubation of organic and mineral soils are heavily influenced by site characteristics when incubated at optimal microbial activity temperature. Sites with considerable differences in temperature, texture, and location differ in carbon source attribution, indicating that site characteristics play a role in soil respiration.

  4. Land factors affecting soil erosion during snow melting: a case study from Lebanon

    Science.gov (United States)

    Darwich, Talal

    2014-05-01

    Soil erosion is one of the major problems facing the mountainous agricultural lands in Lebanon. In order to assess the land factors acting on soil erosion; a study was conducted in the upper watershed of Ibrahim River in the spring months of April, May and June. Water and bed load sediments from six locations alimented by six sub-basins were sampled. Four sub-basins (1, 2, 3 and 6) were dominated by agricultural lands while lands in sub-basins 4 and 7 were occupied by grassland and bare soils. The highest quantities of suspended sediments were found in waters originating from watersheds dominated by agricultural lands, such as Location 2 (713.72 mg L-1 in April 2012). Low clay content and the combination of land occupation (orchards = 71%) and slope (20.7 degrees) caused this ecosystem disturbance. Locations 1, 2, 3 and 6 were alimented by runoff water due to the melting of the snow. For this, the concentrations of sediments decreased by 4 fold between April and May in sub-basin 1 and by 11-14 fold in sub-basins 2, 3 and 6. Globally, some 1669.4 tons of sediments were delivered in the upper river during April. Bed load sediments were separated into 4 classes according to their size. The size of the particles found in the bed load reflected to a large extent the type of soils surrounding the watershed. The range of sand in the regions surrounding locations 6 and 7 was 64% and 82%, while the average in the bed load was 80.9% and 78.25% respectively. The silt content in locations 2, 3 and 5 was well reflected in the concentrations of silt in the bed load. In bed load samples, the exchangeable potassium ranged from 70-250 mg kg-1 in sub-basins dominated by agricultural lands against 20-50 mg kg-1 in sub-basins dominated by grassland and bare rocks. Further quantitative studies need to be conducted especially during the first rains to fully estimate the water load sediments after a prolonged dry season, characterizing the east Mediterranean. Action must be taken for

  5. Effect of yoga practices on pulmonary function tests including transfer factor of lung for carbon monoxide (TLCO) in asthma patients.

    Science.gov (United States)

    Singh, Savita; Soni, Ritu; Singh, K P; Tandon, O P

    2012-01-01

    Prana is the energy, when the self-energizing force embraces the body with extension and expansion and control, it is pranayama. It may affect the milieu at the bronchioles and the alveoli particularly at the alveolo-capillary membrane to facilitate diffusion and transport of gases. It may also increase oxygenation at tissue level. Aim of our study is to compare pulmonary functions and diffusion capacity in patients of bronchial asthma before and after yogic intervention of 2 months. Sixty stable asthmatic-patients were randomized into two groups i.e group 1 (Yoga training group) and group 2 (control group). Each group included thirty patients. Lung functions were recorded on all patients at baseline, and then after two months. Group 1 subjects showed a statistically significant improvement (Pincreased significantly. It was concluded that pranayama & yoga breathing and stretching postures are used to increase respiratory stamina, relax the chest muscles, expand the lungs, raise energy levels, and calm the body.

  6. Key Factors Controlling the Growth of Biological Soil Crusts: Towards a Protocol to Produce Biocrusts in Greenhouse Facilities

    Science.gov (United States)

    Velasco Ayuso, Sergio; María Giraldo Silva, Ana; Nelson, Corey; Barger, Nichole; Antoninka, Anita; Bowker, Matthew; Garcia-Pichel, Ferran

    2016-04-01

    Biological soil crusts (= biocrusts) are topsoil communities comprise of, but not limited to, cyanobacteria, algae, lichens, and mosses that grow intimately associated with soil particles in drylands. Biocrusts have central ecological roles in these areas as sources of carbon and nutrients, and efficiently retain water and prevent soil erosion, which improves soil structure and promotes soil fertility. However, human activities, such as cattle grazing, hiking or military training, are rapidly striking biocrusts. Although it is well known that the inoculation with cyanobacteria or lichens can enhance the recovery of biocrusts in degraded soils, little is known about the factors that control their growth rates. Using soil and inocula from four different sites located in one cold desert (Utah) and in one hot desert (New Mexico), we performed a fractional factorial experiment involving seven factors (water, light, P, N, calcium carbonate, trace metals and type of inoculum) to screen their effects on the growth of biocrusts. After four months, we measured the concentration of chlorophyll a, and we discovered that water, light and P, N or P+N were the most important factors controlling the growth of biocrusts. In the experimental treatments involving these three factors we measured a similar concentration of chlorophyll a (or even higher) to this found in the field locations. Amplification of the 16S rRNA gene segment using universal bacteria primers revealed a microbial community composition in the biocrusts grown that closely corresponds to initial measurements made on inocula. In summary, based on our success in obtaining biocrust biomass from natural communities in greenhouse facilities, without significantly changing its community composition at the phylum and cyanobacterial level, we are paving the road to propose a protocol to produce a high quality-nursed inoculum aiming to assist restoration of arid and semi-arid ecosystems affected by large-scale disturbances.

  7. Combined climate factors alleviate changes in gross soil nitrogen dynamics in heathlands

    DEFF Research Database (Denmark)

    Bjorsne, Anna-Karin; Rutting, Tobias; Ambus, Per

    2014-01-01

    of exposure to three climate change factors, i.e. warming, elevated CO2 (eCO(2)) and summer drought, applied both in isolation and in combination. By conducting laboratory N-15 tracing experiments we show that warming increased both gross N mineralization and nitrification rates. In contrast, gross......The ongoing climate change affects biogeochemical cycling in terrestrial ecosystems, but the magnitude and direction of this impact is yet unclear. To shed further light on the climate change impact, we investigated alterations in the soil nitrogen (N) cycling in a Danish heathland after 5 years......CO(2). In the full treatment combination, simulating the predicted climate for the year 2075, gross N transformations were only moderately affected compared to control, suggesting a minor alteration of the N cycle due to climate change. Overall, our study confirms the importance of multifactorial field...

  8. Soil to plant transfer factor in the vicinity of coal fired power plants

    International Nuclear Information System (INIS)

    Nikolic, J.; Todorovic, D.; Jankovic, M.; Radenkovic, M.; Joksic, J.

    2009-01-01

    In this paper, the monitoring of working and living environment results in 5 coal fired powered plants, for the period from 2004. to 2009. are presented. Soil-plant transfer factor, suitable for estimation of possible contamination of food chain was chosen, as a measure of influence of power plants on the environment. The results gathered over the years of monitoring of working and living environment in the vicinity of the coal fired power plant were analyzed, and it was determined that no significant discrepancy exists comparing to the results reported in world literature. Also, the basic mathematical analysis was conducted, in order to assess the model of the behavior of the results in respect to the frequency count. (author) [sr

  9. Positive matrix factorization as source apportionment of soil lead and cadmium around a battery plant (Changxing County, China).

    Science.gov (United States)

    Xue, Jian-long; Zhi, Yu-you; Yang, Li-ping; Shi, Jia-chun; Zeng, Ling-zao; Wu, Lao-sheng

    2014-06-01

    Chemical compositions of soil samples are multivariate in nature and provide datasets suitable for the application of multivariate factor analytical techniques. One of the analytical techniques, the positive matrix factorization (PMF), uses a weighted least square by fitting the data matrix to determine the weights of the sources based on the error estimates of each data point. In this research, PMF was employed to apportion the sources of heavy metals in 104 soil samples taken within a 1-km radius of a lead battery plant contaminated site in Changxing County, Zhejiang Province, China. The site is heavily contaminated with high concentrations of lead (Pb) and cadmium (Cd). PMF successfully partitioned the variances into sources related to soil background, agronomic practices, and the lead battery plants combined with a geostatistical approach. It was estimated that the lead battery plants and the agronomic practices contributed 55.37 and 29.28%, respectively, for soil Pb of the total source. Soil Cd mainly came from the lead battery plants (65.92%), followed by the agronomic practices (21.65%), and soil parent materials (12.43%). This research indicates that PMF combined with geostatistics is a useful tool for source identification and apportionment.

  10. Soil-plant transfer factors of radionuclides in mangroves in the State of Pernambuco, Brazil

    International Nuclear Information System (INIS)

    Paiva, J.D.S.; França, E.J. de

    2017-01-01

    Mangroves are the main inputs of chemical substances, considering the Brazilian estuarine environments. Natural radionuclides such as 40 K and 228 Ra can be transferred to vegetation. The objective of this work is to determine the transfer factors (TF) and aggregate transfer (TF ag ) of radionuclides 40 K and 228 Ra in the soil-plant system of mangroves in the State of Pernambuco , Brazil. Concentrations of 40 K and 228 Ra activity in the soil of mangroves and in samples composed of leaves of individuals of the native plant species Rhizophora mangle, Laguncularia racemosa and Aviccenia Schaueriana were determined from Gamma Spectrometry with hyper-pure germanium detector (HPGe). The transfer and aggregate transfer factors were calculated according to the methodology proposed in the literature. The respective TF and TF ag values for the 40 K radionuclide were 0.384 and 2.13 x 10 -3 for R. mangle; 0.394 and 2.05 x 10 -3 for L. racemosa and 1.348 and 3.44 x 10 -3 for Avicennia sp. For the radionuclide 228 Ra, the results were lower for R. mangle (TF = 0.089; TF ag = 1.95 x 10 -4 ) and L. race-mosa (TF = 0.142; TF ag = 3.46 x 10 -4 ). For Avicennia schaueriana, the concentrations of 228 Ra activity in the leaves were below the detection limit. The TF values found demonstrated a greater 40 K transfer in Avicennia and 228 Ra dominated mangroves for mangroves where the L. racemosa distribution predominates

  11. Restoring Soil Quality to Mitigate Soil Degradation

    Directory of Open Access Journals (Sweden)

    Rattan Lal

    2015-05-01

    Full Text Available Feeding the world population, 7.3 billion in 2015 and projected to increase to 9.5 billion by 2050, necessitates an increase in agricultural production of ~70% between 2005 and 2050. Soil degradation, characterized by decline in quality and decrease in ecosystem goods and services, is a major constraint to achieving the required increase in agricultural production. Soil is a non-renewable resource on human time scales with its vulnerability to degradation depending on complex interactions between processes, factors and causes occurring at a range of spatial and temporal scales. Among the major soil degradation processes are accelerated erosion, depletion of the soil organic carbon (SOC pool and loss in biodiversity, loss of soil fertility and elemental imbalance, acidification and salinization. Soil degradation trends can be reversed by conversion to a restorative land use and adoption of recommended management practices. The strategy is to minimize soil erosion, create positive SOC and N budgets, enhance activity and species diversity of soil biota (micro, meso, and macro, and improve structural stability and pore geometry. Improving soil quality (i.e., increasing SOC pool, improving soil structure, enhancing soil fertility can reduce risks of soil degradation (physical, chemical, biological and ecological while improving the environment. Increasing the SOC pool to above the critical level (10 to 15 g/kg is essential to set-in-motion the restorative trends. Site-specific techniques of restoring soil quality include conservation agriculture, integrated nutrient management, continuous vegetative cover such as residue mulch and cover cropping, and controlled grazing at appropriate stocking rates. The strategy is to produce “more from less” by reducing losses and increasing soil, water, and nutrient use efficiency.

  12. Geochemical and biotic factors influencing the diversity and distribution of soil microfauna across ice-free coastal habitats in Victoria Land, Antarctica

    Czech Academy of Sciences Publication Activity Database

    Smykla, J.; Porazinska, D. L.; Iakovenko, Nataliia; Devetter, Miloslav; Drewnik, M.; Siang Hii, Y.; Emslie, S.D.

    2018-01-01

    Roč. 116, č. 1 (2018), s. 265-276 ISSN 0038-0717 Institutional support: RVO:67985904 ; RVO:60077344 Keywords : habitat suitability * soil biodiversity * Nematodes Subject RIV: DF - Soil Science OBOR OECD: Soil science Impact factor: 4.857, year: 2016

  13. Microbial properties of soil aggregates created by earthworms and other factors: spherical and prismatic soil aggregates from unreclaimed post-mining sites

    Czech Academy of Sciences Publication Activity Database

    Frouz, J.; Krištůfek, Václav; Livečková, M.; van Loo, D.; Jacobs, P.; van Hoorebeke, L.

    2011-01-01

    Roč. 56, č. 1 (2011), s. 36-43 ISSN 0015-5632 R&D Projects: GA MŠk LC06066; GA MŠk 2B08023; GA AV ČR 1QS600660505 Institutional research plan: CEZ:AV0Z60660521 Keywords : microbial properties * earthworms * spherical and prismatic soil aggregates Subject RIV: EH - Ecology, Behaviour Impact factor: 0.677, year: 2011

  14. Quantifying Components of Soil Respiration and Their Response to Abiotic Factors in Two Typical Subtropical Forest Stands, Southwest China

    Science.gov (United States)

    Yu, Lei; Wang, Yujie; Wang, Yunqi; Sun, Suqi; Liu, Liziyuan

    2015-01-01

    Separating the components of soil respiration and understanding the roles of abiotic factors at a temporal scale among different forest types are critical issues in forest ecosystem carbon cycling. This study quantified the proportions of autotrophic (R A) and heterotrophic (R H) in total soil (R T) respiration using trenching and litter removal. Field studies were conducted in two typical subtropical forest stands (broadleaf and needle leaf mixed forest; bamboo forest) at Jinyun Mountain, near the Three Georges Reservoir in southwest China, during the growing season (Apr.–Sep.) from 2010 to 2012. The effects of air temperature (AT), soil temperature (ST) and soil moisture (SM) at 6cm depth, solar radiation (SR), pH on components of soil respiration were analyzed. Results show that: 1) SR, AT, and ST exhibited a similar temporal trend. The observed abiotic factors showed slight interannual variability for the two forest stands. 2) The contributions of R H and R A to R T for broadleaf and needle leaf mixed forest were 73.25% and 26.75%, respectively, while those for bamboo forest were 89.02% and 10.98%, respectively; soil respiration peaked from June to July. In both stands, CO2 released from the decomposition of soil organic matter (SOM), the strongest contributor to R T, accounted for over 63% of R H. 3) AT and ST were significantly positively correlated with R T and its components (psoil respiration. 4) Components of soil respiration were significantly different between two forest stands (psoil respiration and its components. PMID:25680112

  15. Social and economic factors for adoption of soil and water conservation in West Usambara highlands, Tanzania

    NARCIS (Netherlands)

    Tenge, A.J.M.; Graaff, de J.; Hella, J.P.

    2004-01-01

    Accelerated soil erosion is one of the major constraints to agricultural production in many parts of the Tanzanian highlands. Although several soil and water conservation technologies have been developed and promoted, the adoption of many recommended measures is minimal and soil erosion continues to

  16. Soil factors effects on life history attributes of Leiothrix spiralis and Leiothrix vivipara (Eriocaulaceae) on rupestrian grasslands in Southeastern Brazil.

    Science.gov (United States)

    Coelho, F F; Martins, R P; Figueira, J E C; Demetrio, G R

    2014-11-01

    In this study, we hypothesized that the life history traits of Leiothrix spiralis and L. vivipara would be linked to soil factors of the rupestrian grasslands and that rosette size would be influenced by soil moisture. Soil analyses were performed from five populations of L. spiralis and four populations of L. vivipara. In each area, three replicates were employed in 19 areas of occurrence of Leiothrix species, and we quantified the life history attributes. The microhabitats of these species show low favorability regarding to soil factors. During the dry season, their rosettes decreased in diameter due the loss of its most outlying leaves. The absence of seedlings indicated the low fecundity of both species. However, both species showed rapid population growth by pseudovivipary. Both L. spiralis and L. vivipara exhibit a kind of parental care that was quantified by the presence of connections between parental-rosettes and ramets. The findings of the present study show that the life history traits are linked to soil factors.

  17. Improving and disaggregating N{sub 2}O emission factors for ruminant excreta on temperate pasture soils

    Energy Technology Data Exchange (ETDEWEB)

    Krol, D.J., E-mail: kroldj@tcd.ie [Teagasc, Crops, Land Use and Environment Programme, Johnstown Castle, Co., Wexford (Ireland); Carolan, R. [Agri-Food and Biosciences Institute (AFBI), Belfast BT9 5PX (Ireland); Minet, E. [Teagasc, Crops, Land Use and Environment Programme, Johnstown Castle, Co., Wexford (Ireland); McGeough, K.L.; Watson, C.J. [Agri-Food and Biosciences Institute (AFBI), Belfast BT9 5PX (Ireland); Forrestal, P.J. [Teagasc, Crops, Land Use and Environment Programme, Johnstown Castle, Co., Wexford (Ireland); Lanigan, G.J., E-mail: gary.lanigan@teagasc.ie [Teagasc, Crops, Land Use and Environment Programme, Johnstown Castle, Co., Wexford (Ireland); Richards, K.G. [Teagasc, Crops, Land Use and Environment Programme, Johnstown Castle, Co., Wexford (Ireland)

    2016-10-15

    Cattle excreta deposited on grazed grasslands are a major source of the greenhouse gas (GHG) nitrous oxide (N{sub 2}O). Currently, many countries use the IPCC default emission factor (EF) of 2% to estimate excreta-derived N{sub 2}O emissions. However, emissions can vary greatly depending on the type of excreta (dung or urine), soil type and timing of application. Therefore three experiments were conducted to quantify excreta-derived N{sub 2}O emissions and their associated EFs, and to assess the effect of soil type, season of application and type of excreta on the magnitude of losses. Cattle dung, urine and artificial urine treatments were applied in spring, summer and autumn to three temperate grassland sites with varying soil and weather conditions. Nitrous oxide emissions were measured from the three experiments over 12 months to generate annual N{sub 2}O emission factors. The EFs from urine treated soil was greater (0.30–4.81% for real urine and 0.13–3.82% for synthetic urine) when compared with dung (− 0.02–1.48%) treatments. Nitrous oxide emissions were driven by environmental conditions and could be predicted by rainfall and temperature before, and soil moisture deficit after application; highlighting the potential for a decision support tool to reduce N{sub 2}O emissions by modifying grazing management based on these parameters. Emission factors varied seasonally with the highest EFs in autumn and were also dependent on soil type, with the lowest EFs observed from well-drained and the highest from imperfectly drained soil. The EFs averaged 0.31 and 1.18% for cattle dung and urine, respectively, both of which were considerably lower than the IPCC default value of 2%. These results support both lowering and disaggregating EFs by excreta type. - Highlights: • N{sub 2}O emissions were measured from cattle excreta applied to pasture. • N{sub 2}O was universally higher from urine compared with dung. • N{sub 2}O was driven by rainfall, temperature

  18. Proposal for new best estimates of the soil-to-plant transfer factor of U, Th, Ra, Pb and Po

    Energy Technology Data Exchange (ETDEWEB)

    Vandenhove, H. [Belgian Nuclear Research Centre, Biosphere Impact Studies, Mol (Belgium)], E-mail: hvandenh@sckcen.be; Olyslaegers, G. [Belgian Nuclear Research Centre, Biosphere Impact Studies, Mol (Belgium); Sanzharova, N.; Shubina, O. [RIAREA, Russian Institute of Agricultural Radiology and Agroecology, Obninsk (Russian Federation); Reed, E. [SENES Oak Ridge Inc., Center for Risk Analysis, Oak Ridge, TN (United States); Shang, Z. [Nuclear Safety Center of SEPA, Beijing (China); Velasco, H. [GEA- IMASL, Universidad Nacional de San Luis, Consejo Nacional de Investigaciones Cientificas y Tecnicas (Argentina)

    2009-09-15

    There is increasing interest in radiological assessment of discharges of naturally occurring radionuclides into the terrestrial environment. Such assessments require parameter values for the pathways considered in predictive models. An important pathway for human exposure is via ingestion of food crops and animal products. One of the key parameters in environmental assessment is therefore the soil-to-plant transfer factor to food and fodder crops. The objective of this study was to compile data, based on an extensive literature survey, concerning soil-to-plant transfer factors for uranium, thorium, radium, lead, and polonium. Transfer factor estimates were presented for major crop groups (Cereals, Leafy vegetables, Non-leafy vegetables, Root crops, Tubers, Fruits, Herbs, Pastures/grasses, Fodder), and also for some compartments within crop groups. Transfer factors were also calculated per soil group, as defined by their texture and organic matter content (Sand, Loam, Clay and Organic), and evaluation of transfer factors' dependency on specific soil characteristics was performed following regression analysis. The derived estimates were compared with estimates currently in use.

  19. Spatial distribution patterns of soil mite communities and their relationships with edaphic factors in a 30-year tillage cornfield in northeast China.

    Science.gov (United States)

    Liu, Jie; Gao, Meixiang; Liu, Jinwen; Guo, Yuxi; Liu, Dong; Zhu, Xinyu; Wu, Donghui

    2018-01-01

    Spatial distribution is an important topic in community ecology and a key to understanding the structure and dynamics of populations and communities. However, the available information related to the spatial patterns of soil mite communities in long-term tillage agroecosystems remains insufficient. In this study, we examined the spatial patterns of soil mite communities to explain the spatial relationships between soil mite communities and soil parameters. Soil fauna were sampled three times (August, September and October 2015) at 121 locations arranged regularly within a 400 m × 400 m monitoring plot. Additionally, we estimated the physical and chemical parameters of the same sampling locations. The distribution patterns of the soil mite community and the edaphic parameters were analyzed using a range of geostatistical tools. Moran's I coefficient showed that, during each sampling period, the total abundance of the soil mite communities and the abundance of the dominant mite populations were spatially autocorrelated. The soil mite communities demonstrated clear patchy distribution patterns within the study plot. These patterns were sampling period-specific. Cross-semivariograms showed both negative and positive cross-correlations between soil mite communities and environmental factors. Mantel tests showed a significant and positive relationship between soil mite community and soil organic matter and soil pH only in August. This study demonstrated that in the cornfield, the soil mite distribution exhibited strong or moderate spatial dependence, and the mites formed patches with sizes less than one hundred meters. In addition, in this long-term tillage agroecosystem, soil factors had less influence on the observed pattern of soil mite communities. Further experiments that take into account human activity and spatial factors should be performed to study the factors that drive the spatial distribution of soil microarthropods.

  20. Soil-to-plant transfer factors for natural radionuclides in grass in the vicinity of a former uranium mine

    Energy Technology Data Exchange (ETDEWEB)

    Štrok, Marko, E-mail: Marko.Strok@ijs.si; Smodiš, Borut, E-mail: Borut.Smodis@ijs.si

    2013-08-15

    Highlights: • Soil and grass samples were collected from sites at the uranium mill tailings pile. • {sup 238}U, {sup 230}Th, {sup 226}Ra and {sup 210}Pb activity concentrations were determined. • Soil-to-plant transfer factors were determined and are comparable with literature. • Potential use of grass as a monitor of radionuclide migration was evaluated. • Grass has potential in predicting {sup 238}U and {sup 226}Ra migration. -- Abstract: The activity concentrations of {sup 238}U, {sup 230}Th, {sup 226}Ra and {sup 210}Pb were determined in soil and grass samples collected from sites at the uranium mill tailings waste pile, which lies near the former uranium mine at Žirovski vrh in Slovenia. Soil-to-plant transfer factors were determined and the potential use of grass as a monitor of radionuclide migration from the waste pile was evaluated. It was found that grass was not suitable for monitoring {sup 230}Th and {sup 210}Pb migration (no linear correlation between soil and grass activity concentrations) but has potential in predicting {sup 238}U and {sup 226}Ra migration (linear correlation between soil and grass activity concentrations). Soil-to-plant transfer factors for grass were in the range from 0.0014 to 0.015 kg/kg DM for {sup 238}U, 0.0039 to 0.012 kg/kg DM for {sup 230}Th, 0.035 to 0.46 kg/kg DM for {sup 226}Ra and 0.098 to 1.5 kg/kg DM for {sup 210}Pb.

  1. Spatial variation and driving factors of soil moisture at multi-scales: a case study in Loess Plateau of China

    Science.gov (United States)

    Zhao, W.; Zhang, X.; Liu, Y.; Fang, X.

    2017-12-01

    Currently, the ecological restoration of the Loess Plateau has led to significant achievements such as increases in vegetation coverage, decreases in soil erosion, and enhancement of ecosystem services. Soil moisture shortages, however, commonly occur as a result of limited rainfall and strong evaporation in this semiarid region of China. Since soil moisture is critical in regulating plant growth in these semiarid regions, it is crucial to identify the spatial variation and factors affecting soil moisture at multi-scales in the Loess Plateau of China. In the last several years, extensive studies on soil moisture have been carried out by our research group at the plot, small watershed, watershed, and regional scale in the Loess Plateau, providing some information for vegetation restoration in the region. The main research results are as follows: (1) the highest soil moisture content was in the 0-0.1 m layer with a large coefficient of variation; (2) in the 0-0.1m layer, soil moisture content was negatively correlated with relative elevation, slope and vegetation cover, the correlations among slope, aspect and soil moisture increased with depth increased; (3) as for the deep soil moisture content, the higher spatial variation of deep SMC occurred at 1.2-1.4 m and 4.8-5.0m; (4) the deep soil moisture content in native grassland and farmland were significant higher than that of introduced vegetation; (5) at regional scale, the soil water content under different precipitation zones increased following the increase of precipitation, while, the influencing factors of deep SMC at watershed scale varied with land management types; (6) in the areas with multi-year precipitation of 370 - 440mm, natural grass is more suitable for restoration, and this should be treated as the key areas in vegetation restoration; (7) appropriate planting density and species selection should be taken into account for introduced vegetation management; (8) it is imperative to take the local

  2. Determination of correlation and scaling factors of radionuclides in the contaminated soils from experimental lysimetric field

    International Nuclear Information System (INIS)

    Dulanska, S.

    2009-04-01

    contaminated soils of the experimental lysimeter has been found by the classical least-square method. The pair correlation coefficient R suggests the statistical significance of the y i =b 0 + b 1 a( 241 Am) regression model in which yi is the activity of examined radionuclides 238 Pu and 239 , 240 Pu. The statistical significance of the scaling regression models has been confirmed with the Fisher-Snedecor test and also with high values of pair-correlation coefficients R and D for all contaminated soil samples. Given results confirm theoretical assumptions of a possible correlation between investigated alpha radionuclides ( 238 Pu, 239 , 240 Pu, 241 Am) but do not confirm correlations with strontium ( 90 Sr) in such a complicated matrix like the experimental lysimeter soil. It appears that a combined approach using sufficient amount of experimental data and adequate statistical treatment is necessary for the hypothetic model verification. Based on this, a costly and lengthy radiochemical analysis of one of the investigated alpha radionuclides can be consequently replaced by a statistical factor connecting its content with another alpha radionuclide using a mathematical model. Determination of the activity of a radionuclide in contaminated soil may be determined by indirect methods such as an use of the scaling model, which relate the inferred activity concentration of one radionuclide to another that is measured. 241 Am and 239 , 240 Pu were selected as a suitable key nuclide for the determination of parameter linear scaling model for monitoring of radionuclides in the contaminated lysimer soil. The mechanism 239 , 240 Pu is similar as that of 241 Am and 238 Pu which also have similar chemical and physical properties. The scaling model was calculated with 239 , 240 Pu as the indicator variable for estimated radionuclides 238 Pu, 241 Am or with 241 Am as the indicator variable for estimated radionuclides 2 39 , 240 Pu, 238 Pu. The 239 , 240 Pu fraction is the most prominent

  3. Transfer factor for 210Pb from soil to vegetables in the surrounding environment of Kaiga nuclear power station

    International Nuclear Information System (INIS)

    Rao, Chetan; Karunakara, N.; Yashodhara, I.; Ravi, P.M.

    2013-01-01

    The paper presents a detailed study on site specific soil to vegetable (leafy, fruit and root) transfer factors for 210 Pb for Kaiga region, India where a PHWR, nuclear power plant is in operation. An experimental vegetable field was developed at about 500 m aerial distance from the Nuclear Power Plant (NPP) site at Kaiga to study the site-specific soil to plant transfer factors. Different types of vegetables were grown in the experimental field, during different seasons of the year, using the discharge water from the Kaiga nuclear power plant. The development of the experimental vegetable fields helped in evaluating accurate site-specific data. For a comparative study of the transfer factors obtained for the experimental field, samples cultivated using normal water resources by the local farmers of nearby villages, were also collected and analysed. The soil to leafy vegetable transfer factor of 210 Pb varied in the range of < 1.5 x 10 -2 - 1.6 x 10 -1 with a mean value of 6.0 x 10 -2 . Similarly the soil to fruit vegetable varied in the range of < 1.0 x 10 -2 - 3.4 x 10 -1 and the soil to root vegetable varied in the range of < 1.0 x 10 -2 - 4.0 x 10 -2 with corresponding mean values of 6.0 x 10 -2 and 3.0 x 10 -2 respectively. The annual effective dose due to intake of 210 Pb through leafy vegetables varied in the range of 7.9 - 76.0 μSv a -1 with a mean value of 35.2 ìSv a -1 . And through fruit and root vegetables, it varied in the range of 34.9 - 207 μSv a -1 with a mean value of 119 ìSv a -1 . It was found that radionuclide concentration in plants was not linearly related to soil concentration. (author)

  4. Transfer Factor of Co-60 and Cs-137 from Agricultural Soil to Agricultural Plant of Rice and Beans

    International Nuclear Information System (INIS)

    Suzie, D; Cerdas, T; Susilah, S; Umbara, H

    1996-01-01

    A study to estimate transfer factor of Co-60 and Cs-137 radionuclides from agricultural soil to agricultural plant of beans and rice in Serpong Nuclear Research Center Complex has been carried out. The soil used was that from off site Serpong Nuclear Research Center Complex, the agricultural plant samples were rice with variety of Cisadane, Situgintung, Seratus Malam, and Atomita 4, and for beans were peanut with variety of AH 1781 SI (parent) and A 20 psj (daughter), soybean with variety of Kerinci (parent) and Camar (daughter), and greenbean with variety of Manyar (parent) and Camar (daughter), which obtained from PAIR-BATAN Pasar Jumat. 10 kg of soil was put on the container which layered with plastic. The soil was contaminated with Co-60 and Cs-137 with activity concentration of 10 Bq/kg. Samples were counted with gamma spectrometer. The value of transfer factor was obtained by comparing activity concentration of agricultural plant with that of agricultural soil. The results of transfer factor of Co-60 for rice and beans were 0.12 x 10-2 and 1.05 x 10-2, respectively and the transfer factor of Cs-137 for rice and beans were 0.83 x 10-2 and 2.09 x 10-2, respectively. The gamma emmitter radionuclides counted from the soil of Serpong Nuclear Research Center Complex were Th-228, U-235, Ra-226, Ac-228 and K-40, with activities concentration as background were 35.39 - 101.60; 32.14 - 74.50; 23.37 - 28.57; 20.90 - 31.28 and 5.97 - 8.13 Bq/kg, respectively

  5. Patterns and Risk Factors of Soil-Transmitted Helminthiasis among Orang Asli Subgroups in Peninsular Malaysia

    Science.gov (United States)

    Ngui, Romano; Aziz, Shafie; Chua, Kek Heng; Aidil, Roslan Muhammad; Lee, Soo Ching; Tan, Tiong Kai; Sani, Mistam Mohd; Arine, Ahmad Fadzlun; Rohela, Mahmud; Lim, Yvonne A. L.

    2015-01-01

    A cross-sectional study was conducted to provide comprehensive data on the patterns and associated risk factors of soil-transmitted helminth (STH) infections among five Orang Asli subgroups in Peninsular Malaysia. The overall prevalence of STH infections was 59.9% (95% confidence interval [CI] = 56.1–63.7%). Trichuris trichiura (54.3%; 95% CI = 50.4–58.2%) was the predominant species followed by Ascaris lumbricoides (26.7%; 95% CI = 23.3–30.1%) and hookworm (9.1%; 95% CI = 6.9–11.3%). This study showed diversity for STH infections by subgroup with poverty and personal sanitary behavior as important risk factors for infection. Risk profile analyses indicating that Orang Kuala subgroup who has a generally well-developed infrastructure and better quality of life had a low rate of infection. There is a need for poverty reduction and promotion of deworming programs along with mass scale campaigns to create awareness about health and hygiene to reduce STH infections. PMID:26055746

  6. Patterns and Risk Factors of Soil-Transmitted Helminthiasis Among Orang Asli Subgroups in Peninsular Malaysia.

    Science.gov (United States)

    Ngui, Romano; Aziz, Shafie; Chua, Kek Heng; Aidil, Roslan Muhammad; Lee, Soo Ching; Tan, Tiong Kai; Sani, Mistam Mohd; Arine, Ahmad Fadzlun; Rohela, Mahmud; Lim, Yvonne A L

    2015-08-01

    A cross-sectional study was conducted to provide comprehensive data on the patterns and associated risk factors of soil-transmitted helminth (STH) infections among five Orang Asli subgroups in Peninsular Malaysia. The overall prevalence of STH infections was 59.9% (95% confidence interval [CI] = 56.1-63.7%). Trichuris trichiura (54.3%; 95% CI = 50.4-58.2%) was the predominant species followed by Ascaris lumbricoides (26.7%; 95% CI = 23.3-30.1%) and hookworm (9.1%; 95% CI = 6.9-11.3%). This study showed diversity for STH infections by subgroup with poverty and personal sanitary behavior as important risk factors for infection. Risk profile analyses indicating that Orang Kuala subgroup who has a generally well-developed infrastructure and better quality of life had a low rate of infection. There is a need for poverty reduction and promotion of deworming programs along with mass scale campaigns to create awareness about health and hygiene to reduce STH infections. © The American Society of Tropical Medicine and Hygiene.

  7. Effects of soil depth and plant-soil interaction on microbial community in temperate grasslands of northern China.

    Science.gov (United States)

    Yao, Xiaodong; Zhang, Naili; Zeng, Hui; Wang, Wei

    2018-07-15

    Although the patterns and drivers of soil microbial community composition are well studied, little is known about the effects of plant-soil interactions and soil depth on soil microbial distribution at a regional scale. We examined 195 soil samples from 13 sites along a climatic transect in the temperate grasslands of northern China to measure the composition of and factors influencing soil microbial communities within a 1-m soil profile. Soil microbial community composition was measured using phospholipid fatty acids (PLFA) analysis. Fungi predominated in topsoil (0-10 cm) and bacteria and actinomycetes in deep soils (40-100 cm), independent of steppe types. This variation was explained by contemporary environmental factors (including above- and below-ground plant biomass, soil physicochemical and climatic factors) >58% in the 0-40 cm of soil depth, but soils. Interestingly, when we considered the interactive effects between plant traits (above ground biomass and root biomass) and soil factors (pH, clay content, and soil total carbon, nitrogen, phosphorous), we observed a significant interaction effect occurring at depths of 10-20 cm soil layer, due to different internal and external factors of the plant-soil system along the soil profile. These results improve understanding of the drivers of soil microbial community composition at regional scales. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Assessment of Relationships between Earthworms and Soil Abiotic and Biotic Factors as a Tool in Sustainable Agricultural

    Directory of Open Access Journals (Sweden)

    Radoslava Kanianska

    2016-09-01

    Full Text Available Earthworms are a major component of soil fauna communities. They influence soil chemical, biological, and physical processes and vice versa, their abundance and diversity are influenced by natural characteristics or land management practices. There is need to establish their characteristics and relations. In this study earthworm density (ED, body biomass (EB, and diversity in relation to land use (arable land—AL, permanent grasslands—PG, management, and selected abiotic (soil chemical, physical, climate related and biotic (arthropod density and biomass, ground beetle density, carabid density indicators were analysed at seven different study sites in Slovakia. On average, the density of earthworms was nearly twice as high in PG compared to AL. Among five soil types used as arable land, Fluvisols created the most suitable conditions for earthworm abundance and biomass. We recorded a significant correlation between ED, EB and soil moisture in arable land. In permanent grasslands, the main climate related factor was soil temperature. Relationships between earthworms and some chemical properties (pH, available nutrients were observed only in arable land. Our findings indicate trophic interaction between earthworms and carabids in organically managed arable land. Comprehensive assessment of observed relationships can help in earthworm management to achieve sustainable agricultural systems.

  9. Controlling factors in the dynamics of soil organic carbon from the region of Murcia; Factores de control en la dinamica del Carbono Organico de los suelos de la Region de Murcia

    Energy Technology Data Exchange (ETDEWEB)

    Albaladejo, J.; Martinez-Mena, M.; Almagro, M.; Ruiz-navarro, A.; Ortiz, R.

    2009-07-01

    Sequestration and accumulation of C on the soil is a useful way to reduce the atmospheric concentration of CO{sub 2} and to mitigate the climate change. The purpose of this study was to identify the key factors which determine the accumulation and permanence of CO on the soils of the Murcia Region. The study was arranged from data displayed on the Murcia Region Soils Map (1:100.000). The results showed that quantity of stored CO in the 30cm superficial soil is significantly different depending on soil uses, soil type, altitude and texture. One conclusion is that changes from natural vegetation to cultivated soil are the greatest cause of losses of CO of soil. The increasing of altitude and proportion of thin-silt + clay contributes to CE accumulation. In altitude, the speed of mineralization of organic materials decreases, and the thin particles stimulate the physical protection and the chemical stabilization of CO of soil. (Author) 8 refs.

  10. Factors Influencing Access to Integrated Soil Fertility Management Information and Knowledge and Its Uptake among Smallholder Farmers in Zimbabwe

    Science.gov (United States)

    Gwandu, T.; Mtambanengwe, F.; Mapfumo, P.; Mashavave, T. C.; Chikowo, R.; Nezomba, H.

    2014-01-01

    Purpose: The study evaluated how farmer acquisition, sharing and use patterns of information and knowledge interact with different socioeconomic factors to influence integrated soil fertility management (ISFM) technology uptake. Design/methodology/approach: The study was conducted as part of an evaluation of field-based farmer learning approaches…

  11. Identification of factors most important for ammonia emission from fertilized soils for potato production using principal component analysis

    Science.gov (United States)

    Guodoong Liu; Yuncong Li; Kati W. Migliaccio; Ying Ouyang; Ashok K. Alva

    2011-01-01

    Ammonia (NH3) emissions from fertilized soils are a costly problem that is undermining agricultural and ecological sustainability worldwide. Ammonia emissions from crop production have been reliably documented in recent years. However, insufficient efforts have been made to determine the factors most influential in facilitating NH3 emissions. The goal of this study was...

  12. 3-Way characterization of soils by Procrustes rotation, matrix-augmented principal components analysis and parallel factor analysis

    Czech Academy of Sciences Publication Activity Database

    Andrade, J.M.; Kubista, Mikael; Carlosena, A.; Prada, D.

    2007-01-01

    Roč. 603, č. 1 (2007), s. 20-29 ISSN 0003-2670 Institutional research plan: CEZ:AV0Z50520514 Keywords : PCA * heavy metals * soil Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.186, year: 2007

  13. Test speed and other factors affecting the measurements of tree root properties used in soil reinforcement models

    NARCIS (Netherlands)

    Cofie, P.; Koolen, A.J.

    2001-01-01

    Measured values of the mechanical properties of tree roots are found to be affected by a number of factors. Shear properties of tree roots are found to be partly influenced by size of the testing equipment, level of soil compaction, deformation of the root material and estimated width of the shear

  14. Analysis of Factors Influencing Soil Salinity, Acidity, and Arsenic Concentration in a Polder in Southwest Bangladesh

    Science.gov (United States)

    Ayers, J. C.; Patton, B.; Fry, D. C.; Goodbred, S. L., Jr.

    2017-12-01

    Soil samples were collected on Polder 32 in the coastal zone of SW Bangladesh in wet (October) and dry (May) seasons from 2013-2017 and analyzed to characterize the problems of soil salinization and arsenic contamination and identify their causes. Soils are entisols formed from recently deposited, predominantly silt-sized sediments with low carbon concentrations typical of the local mangrove forests. Soluble (DI extract) arsenic concentrations were below the Government of Bangladesh limit of 50 ppb for drinking water. Soil acidity and extract arsenic concentrations exhibit spatial variation but no consistent trends. In October soil extract As is higher and S and pH are lower than in May. These observations suggest that wet season rainwater oxidizes pyrite, reducing soil S and releasing H+, causing pH to decrease. Released iron is oxidized to form Hydrous Ferric Oxyhydroxides (HFOs), which sorb As and increase extractable As in wet season soils. Changes in pH are small due to pH buffering by soil carbonates. Soil and rice paddy water salinities are consistently higher in May than October, reaching levels in May that reduce rice yields. Rice grown in paddies should be unaffected by salt concentrations in the wet season, while arsenic concentrations in soil may be high enough to cause unsafe As levels in produced rice.

  15. Land management as a factor controlling dissolved organic carbon release from upland peat soils 1: spatial variation in DOC productivity.

    Science.gov (United States)

    Yallop, A R; Clutterbuck, B

    2009-06-01

    The importance of soil storage in global carbon cycling is well recognised and factors leading to increased losses from this pool may act as a positive feedback mechanism in global warming. Upland peat soils are usually assumed to serve as carbon sinks, there is however increasing evidence of carbon loss from upland peat soils, and DOC concentrations in UK rivers have increased markedly over the past three decades. A number of drivers for increasing DOC release from peat soils have been proposed although many of these would not explain fine-scale variations in DOC release observed in many catchments. We examined the effect of land use and management on DOC production in upland peat catchments at two spatial scales within the UK. DOC concentration was measured in streams draining 50 small-scale catchments (b3 km2) in three discrete regions of the south Pennines and one area in the North Yorkshire Moors. Annual mean DOC concentration was also derived from water colour data recorded at water treatment works for seven larger scale catchments (1.5-20 km2) in the south Pennines. Soil type and land use/management in all catchments were characterised from NSRI digital soil data and ortho-corrected colour aerial imagery. Of the factors assessed, representing all combinations of soil type and land use together with catchment slope and area, the proportion of exposed peat surface resulting from new heather burning was consistently identified as the most significant predictor of variation in DOC concentration. This relationship held across all blanket peat catchments and scales. We propose that management activities are driving changes in edaphic conditions in upland peat to those more favourable for aerobic microbial activity and thus enhance peat decomposition leading to increased losses of carbon from these environments.

  16. Soil salinity and matric potential interaction on water use, water use efficiency and yield response factor of bean and wheat.

    Science.gov (United States)

    Khataar, Mahnaz; Mohhamadi, Mohammad Hossien; Shabani, Farzin

    2018-02-08

    We studied the effects of soil matric potential and salinity on the water use (WU), water use efficiency (WUE) and yield response factor (Ky), for wheat (Triticum aestivum cv. Mahdavi) and bean (Phaseoulus vulgaris cv. COS16) in sandy loam and clay loam soils under greenhouse conditions. Results showed that aeration porosity is the predominant factor controlling WU, WUE, Ky and shoot biomass (Bs) at high soil water potentials. As matric potential was decreased, soil aeration improved, with Bs, WU and Ky reaching maximum value at -6 to -10 kPa, under all salinities. Wheat WUE remained almost unchanged by reduction of matric potential under low salinities (EC ≤ 8 dSm -1 ), but increased under higher salinities (EC ≥ 8 dSm -1 ), as did bean WUE at all salinities, as matric potential decreased to -33 kPa. Wheat WUE exceeds that of bean in both sandy loam and clay loam soils. WUE of both plants increased with higher shoot/root ratio and a high correlation coefficient exists between them. Results showed that salinity decreases all parameters, particularly at high potentials (h = -2 kPa), and amplifies the effects of waterlogging. Further, we observed a strong relationship between transpiration (T) and root respiration (Rr) for all experiments.

  17. Relation between natural and anthropogenic factors in the redistribution of radionuclides on the 30 km Chernobyl NPP territory, including the result of countermeasures

    International Nuclear Information System (INIS)

    Kazakov, S.V.; Sukhoruchkin, A.K.; Arkhipov, N.P.; Arkhipov, A.N.; Loginova, L.S.; Meshalkin, G.S.

    1997-01-01

    Before the accident natural and anthropogenic ecosystems occupied about 90% of 30-km zone area, including 36% of forest ecosystem, ploughed lands -28%, meadows and bogs - 18%. About 10% of total areas were occupied by ameliorated lands, separate water reservoirs - 2.8% relatively large area. Ten years after the Chernobyl accident the lands structure was changed: Areas of forest territories became larger (up to 12-13%). Areas of territories occupied by different technical constructions, roads were increased too. Contamination of different objects of 30-km zone territory is very uneven, for instance variation of 137 Cs contamination of soil reaches the same thousand times (From 0.1-5 up to 10000 and more Ci/km 2 )

  18. The soil acidity as restrictive factor of the use of nitrogen fertilizer by spring barley

    International Nuclear Information System (INIS)

    Hejnak, V.; Lippold, H.

    1999-01-01

    In two - year micro - plot trials was studied the effect of soil pH value (pH > 6,5 and pH 15 N in first year and no enriched in second year, rates of 0, 85, 170 and 255 mg N per pot, i.e. 0, 30, 60 and 90 kg N.ha -1 ) on the spring barley productivity and on the use of nitrogen fertilizer by plants in the application year of 15 N and in the following year. The productivity of spring barley is significantly higher in neutral soil than in acid soil. The gradated rates of nitrogen fertilization increased this difference. The total nitrogen uptake by plants was higher in neutral soil. The share of the nitrogen from 'the old soil's supply' in the total uptake by the harvest ranges from 95 to 82 % and is practically identical in studied soils. 'Priming effect' was higher in soil with better fertility (153 - 186 mg N per pot) than in acid soil (to 49 mg N per pot only). The gradated rates of ammonium sulphate increased the uptake nitrogen from fertilizer by harvest of spring barley in the application year of 15 N from 39 mg N to 107 mg N per pot in neutral soil and from 26 mg N to 83 mg N per pot in acid soil and in the following year from 3,05 mg N to 8,15 mg N per pot in neutral soil and from 1,76 mg N to 3,37 mg N per pot in acid soil. The total balance of fertilizer nitrogen ( 15 N) in soil - crop system in two years from application showed that in neutral soil 46 % used by spring barley (42 % in the application year and 4 % in the following year), 16 % rested in soil and loss was 38 % and in acid soil 35 % used by harvest (33 % in first year and 2 % second year), 12 % rested in soil and loss was 53 %. Refs. 5 (author)

  19. A study on factors of variation in environmental radiation - concerning natural radionuclides in soils

    International Nuclear Information System (INIS)

    Kazuko Megumi; Tadao Matsnami; Toshio Ishiyama; Syojiro Kimura; Kenich Okamoto; Tadashi Tsujimoto

    1993-01-01

    The article summarizes experimental results concerning the dependency of concentration of 40 K, 226 Ra and 228 Ra in the top soil samples, collected from several geological zones in the central part of Japan's main island, on their mineral composition, on their particle size-distribution and on their organic content. We may conclude that the concentrations of 40 K, 226 Ra and 228 Ra in the soil mainly depend on the mineral compositions of the soil from their original rocks and on the particle size. In a homologous soil the concentrations of 226 Ra and 228 Ra increase with decreasing particle size and the concentration of 40 K decreases with decreasing particle size. There is a tendency for the part with particle smaller than 10 mesh of each soil sample to contribute to the dose rate more than the part with particle 10 mesh. The concentration of 40 K in the soil samples decreased as ignition loss increased. (2 tabs., 1 fig.)

  20. Application of of artificial neural networks for estimation of soil-plant transfer factor for "1"3"7Cs

    International Nuclear Information System (INIS)

    Santos, Anna Karla Gomes dos

    2016-01-01

    The knowledge of radionuclide behavior in soils is fundamental to calculate the dose due to food ingestion and to evaluate the risks of radioactive exposure of the population. This knowledge associated to the socio-economic characteristics of the affected region will set the radio protective measures to be taken in case of radioactive contamination of rural areas. The soil-plant transfer factor (TF) is the specific parameter value of radiological models to numerically integrate the dynamic processes that occur within the radionuclides in the soil plant system. This measurement, specific to each radionuclide and soil type, is defined ratio between a specific radionuclide activity in the edible part of the plant and its soil activity. However, the absence of linearity between soil concentrations and the measurements in plants indicate the complexity of the transfer process of radionuclide from soil to a plant, making it difficult to forecast the TF ratio in a specific scenario. One of the main radionuclides associated to nuclear accidents impacting rural areas is "1"3"7Cs. This is one of the most worrisome radionuclides because of its physiochemical properties and its chemical similarity with potassium (K) and its extended physical mid-life (t1/2 = 30,17 years) that allows great environmental dispersion, ecological mobility and environmental endurance. Radiological studies related to "1"3"7Cs transfer factor show that pedological parameters that considerably explain the behavior of "1"3"7Cs in soil-plant system are: exchangeable K, clayed minerals, organic matter content and pH in soils. In this work, the computational method of artificial neural network (ANN) was applied to evaluate the possibility to forecast the TF of "1"3"7Cs in cereals, associated to pedological parameters considered potential indicators of its phyto availability: cationic exchange capacity (CEC), exchangeable K and pH. This study demonstrated that the ANN, having only as entry data the

  1. Prevalence and risk factors for giardiasis and soil-transmitted helminthiasis in three municipalities of Southeastern Minas Gerais State, Brazil: risk factors for giardiasis and soil-transmitted helminthiasis.

    Science.gov (United States)

    Pinheiro, Izabella de Oliveira; de Castro, Milton Ferreira; Mitterofhe, Adalberto; Pires, Flávia Alves Condé; Abramo, Clarice; Ribeiro, Luiz Cláudio; Tibiriçá, Sandra Helena Cerrato; Coimbra, Elaine Soares

    2011-05-01

    Giardiasis and soil-transmitted helminthiasis (STH) are parasitic diseases that are among the major health concerns observed in economically disadvantaged populations of developing countries, and have clear social and environmental bases. In Brazil, there is a lack of epidemiologic data concerning these infections in the study area, whose inhabitants have plenty of access to health care services, including good dwelling and adequate sanitary conditions. In this survey we investigated the risk factors for giardiasis and STH in three municipalities with good sanitation, situated in Minas Gerais state, Brazil. A cross-sectional survey was conducted in the municipalities of Piau, Coronel Pacheco and Goianá, in both urban and rural areas. The fieldwork consisted of a questionnaire and the examination of 2,367 stool samples using the Hoffmann, Pons and Janer method. Of all individuals from the population sample, 6.1% were found infected with the parasitic diseases included in this work. Hookworm infection was the most prevalent disease, followed by giardiasis, trichuriasis and ascariasis. Infection was more prevalent in males (8.1%, p < 0.001; odds ratio [OR] = 1.975) and in individuals living in rural areas (8.6%, p = 0.003; OR = 1.693). Multivariate analysis showed that variables such as inadequate sewage discharge (p < 0.001), drinking of unsafe water (p < 0.001), lack of sanitary infrastructure (p = 0.015), and host sex (p < 0.001) were the risk factors more strongly associated with infection status (95% confidence interval [CI]). In this study we demonstrate that giardiasis and STH still persist, infecting people who have good housing conditions and free access to public health care and education.

  2. The relationship between dissolved organic carbon and hydro-climatic factors in peat-muck soil

    Directory of Open Access Journals (Sweden)

    Jaszczyński Jacek

    2015-03-01

    Full Text Available The object of this study was the concentration of dissolved organic carbon (DOC in soil solution related to groundwater table, soil temperature, moisture, redox potential and intensive storm rain and their changes during ten years (2001–2010. The studies were localized in drained and agriculturally used Kuwasy Mire situated in the middle basin of the Biebrza River, north-eastern Poland. The study site was situated on a low peat soil managed as intensively used grassland. The soil was recognized as peat-muck in the second stage of the mucking process. DOC concentration was determined by means of the flow colorimetric method using the Skalar equipment.

  3. Research factors of the electrochemical remediation clay soils from the nitrates

    Energy Technology Data Exchange (ETDEWEB)

    Korolev, V.A.; Babakina, O.A. [Moscow State Univ. (Russian Federation)

    2001-07-01

    The electrokinetic's methods are prevalent [1, 2], but abilities of the method for remediation nitrates contaminated soils are studied insufficiently. The investigations of effectiveness electrochemical remediation are complicated by processes of reduction nitrates to nitrites (that are more toxic) and then to nitrogen in soil under the constant electric current. Therefore, the objectives of the research was following: - Evaluate mechanism of electrokinetic's removing nitrates from soil; - Evaluate basic value of moisture and alkalinity influence for electrochemical remediation of soil from nitrates; - Determine flow-through regime effect on electrokinetic's treating. (orig.)

  4. Experimental study on the solidification and influence factors of MSW stabilized soil

    Directory of Open Access Journals (Sweden)

    Wang Zhiping

    2015-01-01

    Full Text Available The effect of kinds and dosage of curing agent on the curing effect and strength characteristics of municipal solid waste (MSW stabilized soil is very obvious. In order to reveal these effects, this paper uses cement, fly ash, lime and gypsum as main curing agent and additives to make MSW stabilized soil samples of different components and contents and its strength is obtained using unconfined compressive strength test. The results showed that the curing age, dosage of cement, fly ash, lime and gypsum have effect on the strengths of stabilized MSW soil. The bigger the content of cement and fly ash, the higher the strength of stabilized soil. But the amount of lime and gypsum has a critical value. Within the critical value, the strength of the stabilized soil increases with the increasing of the content of the additives, and decreases with the increase of the additives content if the content of the additives exceeds the critical value. The curing age has much effect on the strength of the stabilized soil. The strength of the samples for 7 days is far less than that for 28 days. This can be explained that: when the curing agent is added into the stabilized soil, the connection among the particles of the MSW soil is changed from weak connection to bond connection, and therefore the strength of the curing MSW soil is improved.

  5. Quantification and site-specification of the support practice factor when mapping soil erosion risk associated with olive plantations in the Mediterranean island of Crete.

    Science.gov (United States)

    Karydas, Christos G; Sekuloska, Tijana; Silleos, Georgios N

    2009-02-01

    Due to inappropriate agricultural management practices, soil erosion is becoming one of the most dangerous forms of soil degradation in many olive farming areas in the Mediterranean region, leading to significant decrease of soil fertility and yield. In order to prevent further soil degradation, proper measures are necessary to be locally implemented. In this perspective, an increase in the spatial accuracy of remote sensing datasets and advanced image analysis are significant tools necessary and efficient for mapping soil erosion risk on a fine scale. In this study, the Revised Universal Soil Loss Equation (RUSLE) was implemented in the spatial domain using GIS, while a very high resolution satellite image, namely a QuickBird image, was used for deriving cover management (C) and support practice (P) factors, in order to map the risk of soil erosion in Kolymvari, a typical olive farming area in the island of Crete, Greece. The results comprised a risk map of soil erosion when P factor was taken uniform (conventional approach) and a risk map when P factor was quantified site-specifically using object-oriented image analysis. The results showed that the QuickBird image was necessary in order to achieve site-specificity of the P factor and therefore to support fine scale mapping of soil erosion risk in an olive cultivation area, such as the one of Kolymvari in Crete. Increasing the accuracy of the QB image classification will further improve the resulted soil erosion mapping.

  6. Analyses of the influencing factors of soil microbial functional gene diversity in tropical rainforest based on GeoChip 5.0.

    Science.gov (United States)

    Cong, Jing; Liu, Xueduan; Lu, Hui; Xu, Han; Li, Yide; Deng, Ye; Li, Diqiang; Zhang, Yuguang

    2015-09-01

    To examine soil microbial functional gene diversity and causative factors in tropical rainforests, we used a microarray-based metagenomic tool named GeoChip 5.0 to profile it. We found that high microbial functional gene diversity and different soil microbial metabolic potential for biogeochemical processes were considered to exist in tropical rainforest. Soil available nitrogen was the most associated with soil microbial functional gene structure. Here, we mainly describe the experiment design, the data processing, and soil biogeochemical analyses attached to the study in details, which could be published on BMC microbiology Journal in 2015, whose raw data have been deposited in NCBI's Gene Expression Omnibus (accession number GSE69171).

  7. Determination of point isotropic buildup factors of gamma rays including incoherent and coherent scattering for aluminum, iron, lead, and water by discrete ordinates method

    International Nuclear Information System (INIS)

    Kitsos, S.; Assad, A.; Diop, C.M.; Nimal, J.C.

    1994-01-01

    Exposure and energy absorption buildup factors for aluminum, iron, lead, and water are calculated by the SNID discrete ordinates code for an isotropic point source in a homogeneous medium. The calculation of the buildup factors takes into account the effects of both bound-electron Compton (incoherent) and coherent (Rayleigh) scattering. A comparison with buildup factors from the literature shows that these two effects greatly increase the buildup factors for energies below a few hundred kilo-electron-volts, and thus the new results are improved relative to the experiment. This greater accuracy is due to the increase in the linear attenuation coefficient, which leads to the calculation of the buildup factors for a mean free path with a smaller shield thickness. On the other hand, for the same shield thickness, exposure increases when only incoherent scattering is included and decreases when only coherent scattering is included, so that the exposure finally decreases when both effects are included. Great care must also be taken when checking the approximations for gamma-ray deep-penetration transport calculations, as well as for the cross-section treatment and origin

  8. Remediation of polybrominated diphenyl ethers in soil using Ni/Fe bimetallic nanoparticles: Influencing factors, kinetics and mechanism

    International Nuclear Information System (INIS)

    Xie, Yingying; Fang, Zhanqiang; Cheng, Wen; Tsang, Pokeung Eric; Zhao, Dongye

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs) are commonly used as additive flame retardants in all kinds of electronic products. PBDEs are now ubiquitous in the environment, with soil as a major sink, especially in e-waste recycling sites. This study investigated the degradation of decabromodiphenyl ether (BDE209) in a spiked soil using Ni/Fe bimetallic nanoparticles. The results indicated that Ni/Fe bimetallic nanoparticles are able to degrade BDE209 in soil at ambient temperature and the removal efficiency can reach 72% when an initial pH of 5.6 and at a Ni/Fe dosage of 0.03 g/g. A declining trend in degradation was noticed with decreasing Ni loading and increasing of initial BDE209 concentration. The degradation products of BDE209 were analyzed by GC-MS, which showed that the degradation of BDE209 was a process of stepwise debromination from nBr to (n − 1)Br. And a possible debromination pathway was proposed. At last, the degradation process was analyzed as two-step mechanism, mass transfer and reaction. This current study shows the potential ability of Ni/Fe nanoparticles to be used for removal of PBDEs in contaminated soil. - Highlights: • Ni/Fe bimetallic nanoparticles could effectively degradate BDE209 in soil. • The effects of various factors on remediation of BDE209 in soil using Ni/Fe were considered. • The degradation of BDE209 was a process of stepwise debromination from nBr to (n − 1)Br. • A possible debromination pathway and mechanism about removal of BDE209 in soil were proposed

  9. Nitrogen as a regulatory factor of methane oxidation in soils and sediments

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Laanbroek, H.J.

    2004-01-01

    The oxidation of methane by methane-oxidising microorganisms is an important link in the global methane budget. Oxic soils are a net sink while wetland soils are a net source of atmospheric methane. It has generally been accepted that the consumption of methane in upland as well as lowland systems

  10. Factors influencing soil aggregation and particulate organic matter responses to bioenergy crops across a topographic gradient

    Science.gov (United States)

    Todd A. Ontl; Cynthia A. Cambardella; Lisa A. Schulte; Randall K. Kolka

    2015-01-01

    Bioenergy crops have the potential to enhance soil carbon (C) pools from increased aggregation and the physical protection of organic matter; however, our understanding of the variation in these processes over heterogeneous landscapes is limited. In particular, little is known about the relative importance of soil properties and root characteristics for the physical...

  11. Factors controlling soil organic carbon stability along a temperate forest altitudinal gradient

    Science.gov (United States)

    Tian, Qiuxiang; He, Hongbo; Cheng, Weixin; Bai, Zhen; Wang, Yang; Zhang, Xudong

    2016-01-01

    Changes in soil organic carbon (SOC) stability may alter carbon release from the soil and, consequently, atmospheric CO2 concentration. The mean annual temperature (MAT) can change the soil physico-chemical characteristics and alter the quality and quantity of litter input into the soil that regulate SOC stability. However, the relationship between climate and SOC stability remains unclear. A 500-day incubation experiment was carried out on soils from an 11 °C-gradient mountainous system on Changbai Mountain in northeast China. Soil respiration during the incubation fitted well to a three-pool (labile, intermediate and stable) SOC decomposition model. A correlation analysis revealed that the MAT only influenced the labile carbon pool size and not the SOC stability. The intermediate carbon pool contributed dominantly to cumulative carbon release. The size of the intermediate pool was strongly related to the percentage of sand particle. The decomposition rate of the intermediate pool was negatively related to soil nitrogen availability. Because both soil texture and nitrogen availability are temperature independent, the stability of SOC was not associated with the MAT, but was heavily influenced by the intrinsic processes of SOC formation and the nutrient status. PMID:26733344

  12. Factors affecting N immobilisation/mineralisation kinetics for cellulose-, glucose- and straw-amended sandy soils

    NARCIS (Netherlands)

    Vinten, A.J.A.; Whitmore, A.P.; Bloem, J.; Howard, R.; Wright, F.

    2002-01-01

    The kinetics of nitrogen immobilization/mineralization for cellulose-, glucose- and straw-amended sandy soils were investigated in a series of laboratory incubations. Three Scottish soils expected to exhibit a range of biological activity were used: aloamy sand, intensively cropped horticultural

  13. Magnitude of Annual Soil Loss from a Hilly Cultivated Slope in Northern Vietnam and Evaluation of Factors Controlling Water Erosion

    International Nuclear Information System (INIS)

    Kurosawa, K.; Hai Do, N.; Nguyen, T.C.; Egashira, K.

    2010-01-01

    A soil erosion experiment was conducted in northern Vietnam over three rainy seasons to clarify the magnitude of soil loss and factors controlling water erosion. The plot had a low (8%) or medium (14.5%) slope with land-cover of cassava or morning glory or being bare. Annual soil loss (177 to 2,361 g/m 2 ) was a tolerable level in all low-slope plots but was not in some medium-slope plots. The effects of slope gradient and seasonal rainfall on the mean daily soil loss of the season were confirmed, but the effect of land-cover was not, owing to the small canopy cover ratio or leaf area index during the season. The very high annual soil loss (>2,200 g/m 2 ) observed in the first year of some medium-slope plots was the site-specific effect from initial land preparation. Since the site-specific effect was large, the preparation must be done carefully on the slope

  14. Distribution of petroleum degrading genes and factor analysis of petroleum contaminated soil from the Dagang Oilfield, China

    Science.gov (United States)

    Liu, Qinglong; Tang, Jingchun; Bai, Zhihui; Hecker, Markus; Giesy, John P.

    2015-01-01

    Genes that encode for enzymes that can degrade petroleum hydrocarbons (PHs) are critical for the ability of microorganisms to bioremediate soils contaminated with PHs. Distributions of two petroleum-degrading genes AlkB and Nah in soils collected from three zones of the Dagang Oilfield, Tianjin, China were investigated. Numbers of copies of AlkB ranged between 9.1 × 105 and 1.9 × 107 copies/g dry mass (dm) soil, and were positively correlated with total concentrations of PHs (TPH) (R2 = 0.573, p = 0.032) and alkanes (C33 ~ C40) (R2 = 0.914, p < 0.01). The Nah gene was distributed relatively evenly among sampling zones, ranging between 1.9 × 107 and 1.1 × 108 copies/g dm soil, and was negatively correlated with concentrations of total aromatic hydrocarbons (TAH) (R2 = −0.567, p = 0.035) and ∑16 PAHs (R2 = −0.599, p = 0.023). Results of a factor analysis showed that individual samples of soils were not ordinated as a function of the zones. PMID:26086670

  15. Variations in soil-to-red pepper transfer factors of radionuclides with time of their application and fruit harvest

    International Nuclear Information System (INIS)

    Choi, Yong Ho; Lee, Won Yun; Lim, Kwang Muk; Park, Soo Won; Lee, Myung Ho; Lee, Chang Woo; Lee, Hyun Duk; Lee, Jeong Ho

    1997-01-01

    A mixed solution of 54 Mn, 60 Co, 85 Sr and 137 Cs was applied to the soil of culture boxes in a greenhouse 2 days before transplanting red pepper and at 3 different times during its growth for investigating transfer factors (m 2 /kg-dry) for its green and red fruits. Transfer factors varied with radionuclide, application time and harvest time by factors of about 20-100. They decreased mostly radionuclide, application time and harvest time by factors of about 20-100. They decreased mostly in the order of 85 Sr> 54 Mn> 60 Co> 137 Cs while 54 Mn and 60 Co was higher than 85 Sr when time lapse between application and harvest was short. Transfer factors of 85 Sr and 137 Cs at the last application were lower than those at the previous one by factors of 3-20 depending on harvest time. Variations in 54 Mn and 60 Co transfer factors with application time after transplanting were comparatively low. Transfer factors of 54 Mn, 60 Co and 85 Sr mixed with topsoil before transplanting were up to 3-9 times higher than those for the application onto soil surface 2 days after transplanting root-uptake concentrations of the radionuclides in red pepper fruit and taking proper measures for its harvest and consumption at the event of an accidental release during the growing season of red pepper

  16. Morphological and molecular characterization of selected desert soil cyanobacteria: Three species new to science including Mojavia pulchra gen. et sp. nov

    Czech Academy of Sciences Publication Activity Database

    Řeháková, Klára; Johansen, J. R.; Casamatta, D.A.; Xuesong, L.; Vincent, J.

    2007-01-01

    Roč. 46, č. 5 (2007), s. 481-502 ISSN 0031-8884 R&D Projects: GA ČR GP206/03/P024 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z60170517 Keywords : Nostoc * desert * taxonomy Subject RIV: EF - Botanics Impact factor: 1.358, year: 2007

  17. Mapping of Schistosomiasis and Soil-Transmitted Helminths in Namibia: The First Large-Scale Protocol to Formally Include Rapid Diagnostic Tests.

    Directory of Open Access Journals (Sweden)

    José Carlos Sousa-Figueiredo

    Full Text Available Namibia is now ready to begin mass drug administration of praziquantel and albendazole against schistosomiasis and soil-transmitted helminths, respectively. Although historical data identifies areas of transmission of these neglected tropical diseases (NTDs, there is a need to update epidemiological data. For this reason, Namibia adopted a new protocol for mapping of schistosomiasis and geohelminths, formally integrating rapid diagnostic tests (RDTs for infections and morbidity. In this article, we explain the protocol in detail, and introduce the concept of 'mapping resolution', as well as present results and treatment recommendations for northern Namibia.This new protocol allowed a large sample to be surveyed (N = 17,896 children from 299 schools at relatively low cost (7 USD per person mapped and very quickly (28 working days. All children were analysed by RDTs, but only a sub-sample was also diagnosed by light microscopy. Overall prevalence of schistosomiasis in the surveyed areas was 9.0%, highly associated with poorer access to potable water (OR = 1.5, P<0.001 and defective (OR = 1.2, P<0.001 or absent sanitation infrastructure (OR = 2.0, P<0.001. Overall prevalence of geohelminths, more particularly hookworm infection, was 12.2%, highly associated with presence of faecal occult blood (OR = 1.9, P<0.001. Prevalence maps were produced and hot spots identified to better guide the national programme in drug administration, as well as targeted improvements in water, sanitation and hygiene. The RDTs employed (circulating cathodic antigen and microhaematuria for Schistosoma mansoni and S. haematobium, respectively performed well, with sensitivities above 80% and specificities above 95%.This protocol is cost-effective and sensitive to budget limitations and the potential economic and logistical strains placed on the national Ministries of Health. Here we present a high resolution map of disease prevalence levels, and treatment regimens are

  18. Factors impacting manganese transport from soils into rivers using data from Shale Hills CZO

    Science.gov (United States)

    Herndon, E.; Brantley, S. L.

    2012-12-01

    Many soils are enriched in trace elements due to atmospheric inputs from industrial sources but little is known about how long these contaminants persist in soils or the rates at which they are transferred into rivers. Modeling the movement of contaminants through the environment is complicated by the heterogeneity of soils and the variability of contaminant mobility across spatial scales. In this study, we use soil, water, and vegetation chemistry to compare rates of Mn contaminant mobilization and removal from soils at ridge, hillslope, and catchment-scales in the Susquehanna Shale Hills Critical Zone Observatory (SSHCZO). The SSHCZO is a first-order, forested watershed located within the Susquehanna River Basin (SRB) in Pennsylvania, U.S.A. Studies from the SSHCZO are compared to trends in long-term water quality measurements for the Susquehanna River to evaluate terrestrial inputs to the river system. At SSHCZO, we find that Mn is being removed ~7x more quickly from soils in swales than soils on convex-upward hillslopes; thus, swales are a large source of dissolved Mn to the stream. Release rates of Mn from all soils are dwarfed by rates of uptake into vegetation, consistent with the hypothesis that trees temporarily slow the removal of atmospherically-deposited Mn from the soil by accumulating Mn in plant biomass. However, elevated levels of dissolved organic carbon in soil pore waters may enhance Mn release in the swales; therefore, vegetation may first decrease then increase rates of Mn removal from soils over the long-term. Unlike the major rock-derived elements which exhibit chemostatic behavior, Mn concentrations in the stream vary widely over a large range of stream discharge rates. High Mn fluxes in the stream occur in short pulses that only weakly respond to precipitation events, suggesting that dissolved Mn loads in rivers are not solely driven by the hydrology but are rather strongly impacted by processes in the soil and stream sediments. Current

  19. [Soil seed bank and its correlations with aboveground vegetation and environmental factors in water level fluctuating zone of Danjiangkou Reservoir, Central China].

    Science.gov (United States)

    Liu, Rui-Xue; Zhan, Juan; Shi, Zhi-Hua; Chen, Long-qing

    2013-03-01

    Taking the water level fluctuating zone of the Danjiangkou Reservoir as a case, and by the method of hierarchical cluster analysis, the soil seed banks at 37 sampling plots within the areas of 140-145 m elevation were divided into 6 groups, and the species composition, density, and diversity of the soil seed banks among the groups were compared. The differences between the soil seed banks and the aboveground vegetations were analyzed by S0rensen similarity coefficient, and the correlations among the soil seed banks, aboveground vegetations, and environmental factors were explored by principal component analysis (PCA) and multivariable regression analysis. At the same altitudes of the water level fluctuating zone, the species composition of the soil seed banks had obvious heterogeneity, and the density and diversity indices of the soil seed banks among different groups were great. The similarity coefficient between the soil seed banks and aboveground vegetations was low, and the species number in the soil seed banks was obviously lesser than that in the aboveground vegetations. The density of the soil seed banks was highly positively correlated with the aboveground vegetations coverage and species number and the soil texture, but highly negatively correlated with the soil water-holding capacity and soil porosity.

  20. Transfer factor of Radium -226, lead-210 and Polonium-210 from Norm contaminated soil to Atriplex, Afelfa and Bermuda grasses

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Mukhallati, H.; Al-Hamwi, A.

    2011-10-01

    transfer factors of Radium -226, lead-210 and Polonium-210 from contaminated soil with oil coproduced water to grazing plants in the north eastern region of Syria have been determined. contaminated soil was collected from one of the AL-Furat Petroleum Oil company oil fields;soil was distributed into several pots where the studied plants were planted in order to study the transfer factors of radioisotopes to them. Results have shown that the mean transfer factors of radium to green parts have reached has reached 0.0016 in Atriplex halimus L.,0.0021 in Atriplex canescens Nutt, 0.0025 in Atriplex Leucoclada Bioss,0.0082 in Bermuda grass and 0.0167 in Medicago Sativ L,which was the highest,while the transfer factors of polonium and lead were ten times higher than those for radium and reacted 0.012 in Atriplex Leucoclada Bioss, 0.011 in Atriplex canescens Nutt, 0.007 in Atriplex halimus L.0.32 in bermuda grass and 0.025 in Afelfa.(author)

  1. Modeling soil organic carbon dynamics and their driving factors in the main global cereal cropping systems

    Science.gov (United States)

    Wang, Guocheng; Zhang, Wen; Sun, Wenjuan; Li, Tingting; Han, Pengfei

    2017-10-01

    Changes in the soil organic carbon (SOC) stock are determined by the balance between the carbon input from organic materials and the output from the decomposition of soil C. The fate of SOC in cropland soils plays a significant role in both sustainable agricultural production and climate change mitigation. The spatiotemporal changes of soil organic carbon in croplands in response to different carbon (C) input management and environmental conditions across the main global cereal systems were studied using a modeling approach. We also identified the key variables that drive SOC changes at a high spatial resolution (0.1° × 0.1°) and over a long timescale (54 years from 1961 to 2014). A widely used soil C turnover model (RothC) and state-of-the-art databases of soil and climate variables were used in the present study. The model simulations suggested that, on a global average, the cropland SOC density increased at annual rates of 0.22, 0.45 and 0.69 Mg C ha-1 yr-1 under crop residue retention rates of 30, 60 and 90 %, respectively. Increasing the quantity of C input could enhance soil C sequestration or reduce the rate of soil C loss, depending largely on the local soil and climate conditions. Spatially, under a specific crop residue retention rate, relatively higher soil C sinks were found across the central parts of the USA, western Europe, and the northern regions of China. Relatively smaller soil C sinks occurred in the high-latitude regions of both the Northern and Southern hemispheres, and SOC decreased across the equatorial zones of Asia, Africa and America. We found that SOC change was significantly influenced by the crop residue retention rate (linearly positive) and the edaphic variable of initial SOC content (linearly negative). Temperature had weak negative effects, and precipitation had significantly negative impacts on SOC changes. The results can help guide carbon input management practices to effectively mitigate climate change through soil C

  2. Modeling soil organic carbon dynamics and their driving factors in the main global cereal cropping systems

    Directory of Open Access Journals (Sweden)

    G. Wang

    2017-10-01

    Full Text Available Changes in the soil organic carbon (SOC stock are determined by the balance between the carbon input from organic materials and the output from the decomposition of soil C. The fate of SOC in cropland soils plays a significant role in both sustainable agricultural production and climate change mitigation. The spatiotemporal changes of soil organic carbon in croplands in response to different carbon (C input management and environmental conditions across the main global cereal systems were studied using a modeling approach. We also identified the key variables that drive SOC changes at a high spatial resolution (0.1°  ×  0.1° and over a long timescale (54 years from 1961 to 2014. A widely used soil C turnover model (RothC and state-of-the-art databases of soil and climate variables were used in the present study. The model simulations suggested that, on a global average, the cropland SOC density increased at annual rates of 0.22, 0.45 and 0.69 Mg C ha−1 yr−1 under crop residue retention rates of 30, 60 and 90 %, respectively. Increasing the quantity of C input could enhance soil C sequestration or reduce the rate of soil C loss, depending largely on the local soil and climate conditions. Spatially, under a specific crop residue retention rate, relatively higher soil C sinks were found across the central parts of the USA, western Europe, and the northern regions of China. Relatively smaller soil C sinks occurred in the high-latitude regions of both the Northern and Southern hemispheres, and SOC decreased across the equatorial zones of Asia, Africa and America. We found that SOC change was significantly influenced by the crop residue retention rate (linearly positive and the edaphic variable of initial SOC content (linearly negative. Temperature had weak negative effects, and precipitation had significantly negative impacts on SOC changes. The results can help guide carbon input management practices to

  3. Modeling spatial patterns of soil respiration in maize fields from vegetation and soil property factors with the use of remote sensing and geographical information system.

    Directory of Open Access Journals (Sweden)

    Ni Huang

    Full Text Available To examine the method for estimating the spatial patterns of soil respiration (Rs in agricultural ecosystems using remote sensing and geographical information system (GIS, Rs rates were measured at 53 sites during the peak growing season of maize in three counties in North China. Through Pearson's correlation analysis, leaf area index (LAI, canopy chlorophyll content, aboveground biomass, soil organic carbon (SOC content, and soil total nitrogen content were selected as the factors that affected spatial variability in Rs during the peak growing season of maize. The use of a structural equation modeling approach revealed that only LAI and SOC content directly affected Rs. Meanwhile, other factors indirectly affected Rs through LAI and SOC content. When three greenness vegetation indices were extracted from an optical image of an environmental and disaster mitigation satellite in China, enhanced vegetation index (EVI showed the best correlation with LAI and was thus used as a proxy for LAI to estimate Rs at the regional scale. The spatial distribution of SOC content was obtained by extrapolating the SOC content at the plot scale based on the kriging interpolation method in GIS. When data were pooled for 38 plots, a first-order exponential analysis indicated that approximately 73% of the spatial variability in Rs during the peak growing season of maize can be explained by EVI and SOC content. Further test analysis based on independent data from 15 plots showed that the simple exponential model had acceptable accuracy in estimating the spatial patterns of Rs in maize fields on the basis of remotely sensed EVI and GIS-interpolated SOC content, with R2 of 0.69 and root-mean-square error of 0.51 µmol CO2 m(-2 s(-1. The conclusions from this study provide valuable information for estimates of Rs during the peak growing season of maize in three counties in North China.

  4. Modeling Spatial Patterns of Soil Respiration in Maize Fields from Vegetation and Soil Property Factors with the Use of Remote Sensing and Geographical Information System

    Science.gov (United States)

    Huang, Ni; Wang, Li; Guo, Yiqiang; Hao, Pengyu; Niu, Zheng

    2014-01-01

    To examine the method for estimating the spatial patterns of soil respiration (Rs) in agricultural ecosystems using remote sensing and geographical information system (GIS), Rs rates were measured at 53 sites during the peak growing season of maize in three counties in North China. Through Pearson's correlation analysis, leaf area index (LAI), canopy chlorophyll content, aboveground biomass, soil organic carbon (SOC) content, and soil total nitrogen content were selected as the factors that affected spatial variability in Rs during the peak growing season of maize. The use of a structural equation modeling approach revealed that only LAI and SOC content directly affected Rs. Meanwhile, other factors indirectly affected Rs through LAI and SOC content. When three greenness vegetation indices were extracted from an optical image of an environmental and disaster mitigation satellite in China, enhanced vegetation index (EVI) showed the best correlation with LAI and was thus used as a proxy for LAI to estimate Rs at the regional scale. The spatial distribution of SOC content was obtained by extrapolating the SOC content at the plot scale based on the kriging interpolation method in GIS. When data were pooled for 38 plots, a first-order exponential analysis indicated that approximately 73% of the spatial variability in Rs during the peak growing season of maize can be explained by EVI and SOC content. Further test analysis based on independent data from 15 plots showed that the simple exponential model had acceptable accuracy in estimating the spatial patterns of Rs in maize fields on the basis of remotely sensed EVI and GIS-interpolated SOC content, with R2 of 0.69 and root-mean-square error of 0.51 µmol CO2 m−2 s−1. The conclusions from this study provide valuable information for estimates of Rs during the peak growing season of maize in three counties in North China. PMID:25157827

  5. Effects of soil amendment with different carbon sources and other factors on the bioremediation of an aged PAH-contaminated soil.

    Science.gov (United States)

    Teng, Ying; Luo, Yongming; Ping, Lifeng; Zou, Dexun; Li, Zhengao; Christie, Peter

    2010-04-01

    Carbon supplementation, soil moisture and soil aeration are believed to enhance in situ bioremediation of PAH-contaminated soils by stimulating the growth of indigenous microorganisms. However, the effects of added carbon and nitrogen together with soil moisture and soil aeration on the dissipation of PAHs and on associated microbial counts have yet to be fully assessed. In this study the effects on bioremediation of carbon source, carbon-to-nitrogen ratio, soil moisture and aeration on an aged PAH-contaminated agricultural soil were studied in microcosms over a 90-day period. Additions of starch, glucose and sodium succinate increased soil bacterial and fungal counts and accelerated the dissipation of phenanthrene and benzo(a)pyrene in soil. Decreases in phenanthrene and benzo(a)pyrene concentrations were effective in soil supplemented with glucose and sodium succinate (both 0.2 g C kg(-1) dry soil) and starch (1.0 g C kg(-1) dry soil). The bioremediation effect at a C/N ratio of 10:1 was significantly higher (P Soil microbial counts and PAH dissipation were lower in the submerged soil but soil aeration increased bacterial and fungal counts, enhanced indigenous microbial metabolic activities, and accelerated the natural degradation of phenanthrene and benzo(a)pyrene. The results suggest that optimizing carbon source, C/N ratio, soil moisture and aeration conditions may be a feasible remediation strategy in certain PAH contaminated soils with large active microbial populations.

  6. Modelling site-specific N2O emission factors from Austrian agricultural soils for targeted mitigation measures (NitroAustria)

    Science.gov (United States)

    Amon, Barbara; Zechmeister-Boltenstern, Sophie; Kasper, Martina; Foldal, Cecilie; Schiefer, Jasmin; Kitzler, Barbara; Schwarzl, Bettina; Zethner, Gerhard; Anderl, Michael; Sedy, Katrin; Gaugitsch, Helmut; Dersch, Georg; Baumgarten, Andreas; Haas, Edwin; Kiese, Ralf

    2016-04-01

    Results from a previous project "FarmClim" highlight that the IPCC default emission factor is not able to reflect region specific N2O emissions from Austrian arable soils. The methodology is limited in identifying hot spots and hot moments of N2O emissions. When estimations are based on default emission factors no recommendations can be given on optimisation measures that would lead to a reduction of soil N2O emissions. The better the knowledge is about Nitrogen and Carbon budgets in Austrian agricultural managed soils the better the situation can be reflected in the Austrian GHG emission inventory calculations. Therefore national and regionally modelled emission factors should improve the evidence for national deviation from the IPCC default emission factors and reduce the uncertainties. The overall aim of NitroAustria is to identify the drivers for N2O emissions on a regional basis taking different soil types, climate, and agricultural management into account. We use the LandscapeDNDC model to update the N2O emission factors for N fertilizer and animal manure applied to soils. Key regions in Austria were selected and region specific N2O emissions calculated. The model runs at sub-daily time steps and uses data such as maximum and minimum air temperature, precipitation, radiation, and wind speed as meteorological drivers. Further input data are used to reflect agricultural management practices, e.g., planting/harvesting, tillage, fertilizer application, irrigation and information on soil and vegetation properties for site characterization and model initialization. While at site scale, arable management data (crop cultivation, rotations, timings etc.) is obtained by experimental data from field trials or observations, at regional scale such data need to be generated using region specific proxy data such as land use and management statistics, crop cultivations and yields, crop rotations, fertilizer sales, manure resulting from livestock units etc. The farming

  7. Lead (Pb) and other metals in New York City community garden soils: factors influencing contaminant distributions.

    Science.gov (United States)

    Mitchell, Rebecca G; Spliethoff, Henry M; Ribaudo, Lisa N; Lopp, Donna M; Shayler, Hannah A; Marquez-Bravo, Lydia G; Lambert, Veronique T; Ferenz, Gretchen S; Russell-Anelli, Jonathan M; Stone, Edie B; McBride, Murray B

    2014-04-01

    Urban gardens provide affordable fresh produce to communities with limited access to healthy food but may also increase exposure to lead (Pb) and other soil contaminants. Metals analysis of 564 soil samples from 54 New York City (NYC) community gardens found at least one sample exceeding health-based guidance values in 70% of gardens. However, most samples (78%) did not exceed guidance values, and medians were generally below those reported in NYC soil and other urban gardening studies. Barium (Ba) and Pb most frequently exceeded guidance values and along with cadmium (Cd) were strongly correlated with zinc (Zn), a commonly measured nutrient. Principal component analysis suggested that contaminants varied independently from organic matter and geogenic metals. Contaminants were associated with visible debris and a lack of raised beds; management practices (e.g., importing uncontaminated soil) have likely reduced metals concentrations. Continued exposure reduction efforts would benefit communities already burdened by environmental exposures. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Responses of calotropis procera and cassia senna to some soil factors in central Sudan

    International Nuclear Information System (INIS)

    Hayati, A. A.; Yahia, A. Y.

    2002-01-01

    The responses of calotropis procera and cassia senna to soil ph, Ca, Mg, K, Na, Mn, Fe, NH 4 -N and P were investigated in three sites in central Sudan, namely Omdurman, Wadelmajzob (Wad Medani) and Kosti. The investigation was carried out by chemical analysis of soil and pant samples collected randomly from 25 sampling points at each site. The data of the soil chemical analysis were analysed using the principal component analysis (PCA). The PCA reflected some what low range of variation in the distribution of the soil nutrient within each of the three investigated sites. Chemical analysis of C. procera and C. senna plants, collected from three investigated sites, showed that they have different levels of nutrients uptake. Although C. senna tends to have low mineral requirements compared with C. procera. it was completely absent from Kosti sit. This may be due to the acidity and high Mn levels at this site.(Author)

  9. Lead (Pb) and other metals in New York City community garden soils: factors influencing contaminant distributions

    Science.gov (United States)

    Mitchell, Rebecca G.; Spliethoff, Henry M.; Ribaudo, Lisa N.; Lopp, Donna M.; Shayler, Hannah A.; Marquez-Bravo, Lydia G.; Lambert, Veronique T.; Ferenz, Gretchen S.; Russell-Anelli, Jonathan M.; Stone, Edie B.; McBride, Murray B.

    2014-01-01

    Urban gardens provide affordable fresh produce to communities with limited access to healthy food but may also increase exposure to lead (Pb) and other soil contaminants. Metals analysis of 564 soil samples from 54 New York City (NYC) community gardens found at least one sample exceeding health-based guidance values in 70% of gardens. However, most samples (78%) did not exceed guidance values, and medians were generally below those reported in NYC soil and other urban gardening studies. Barium (Ba) and Pb most frequently exceeded guidance values and along with cadmium (Cd) were strongly correlated with zinc (Zn), a commonly measured nutrient. Principal component analysis suggested that contaminants varied independently from organic matter and geogenic metals. Contaminants were associated with visible debris and a lack of raised beds; management practices (e.g., importing uncontaminated soil) have likely reduced metals concentrations. Continued exposure reduction efforts would benefit communities already burdened by environmental exposures. PMID:24502997

  10. [Soil organic carbon sequestration rate and its influencing factors in farmland of Guanzhong Plain: a case study in Wugong County, Shannxi Province].

    Science.gov (United States)

    Zhang, Xiao-Wei; Xu, Ming-Xiang

    2013-07-01

    Take Wugong County as an example, soil carbon storage and soil carbon sequestration rate were calculated, the change law of farmland soil organic carbon was explored, and the relationship of farmland soil organic carbon and natural factors, human factors was further revealed. The results of the study showed that: (1) The soil organic carbon contents in 80% of the sampling sites were in the range of 8.0-12.0 g x kg(-1), and the organic carbon contents in 0-20 cm soils showed a normal distribution. (2) In 2011, the organic carbon density of the 0-20 cm farmland soil was 26.3 t x hm(-2), below the national average soil organic carbon density (33.45 t x hm(-2)) of the arable layer. In the last 30 years, the soil carbon sequestration rate in the 0-20 cm layer was 71.3 kg x (hm2 x a)(-1), and in the past five years, the carbon sequestration rate was 480 kg x (hm x a)(-1). The recent carbon sequestration rate was higher than the national average soil carbon sequestration rate of the arable layer [380.78 kg x (hm2 x a)(-1)]. (3) In the semi-humid plain region, soil organic carbon was mainly affected by soil types, landform types, organic fertilizer. Soil types accounted for 30.2% of the organic carbon variability; the landform types and the organic fertilizer could explain 37.7% and 32.1%, respectively. The results of the comprehensive analysis showed that the farmland soil organic carbon density of Wugong County in the past 30 years is increasing, and this probably relies on the utilization of chemical fertilizer and the returning straw. Further study should be conducted on the impact of the chemical fertilizer and returning straw.

  11. Experimental description and stochastic modelling of transfers using a scaling factor for the hydrodynamic properties of the soils

    International Nuclear Information System (INIS)

    Vauclin, M.; Vachaud, G.; Imbernon, J.; Dancette, C.

    1983-01-01

    It is well known that natural soils do not have constant hydrodynamic properties on the plot scale. Experimentally, this means that a water balance obtained in an access tube by means of a neutron moisture gauge and tensiometers is not necessarily representative of the whole range studied. For modelling purposes the deterministic aspect of transfers should be associated with a stochastic description of the hydrodynamic parameters (pressure, water content, hydraulic conductivity). An experiment was carried out in a one-hectare plot of bare soil at Bambey (Senegal) in order to characterize its variability: 28 infiltration tests were performed at the points of a 23x23 m grid. At each of these points, the insertion of a neutron access tube to a depth of 2.0 m, and the positioning of three tensiometers at depths of 100, 110 and 120 cm made it possible also to monitor the redistribution of water and to derive the pressure-water content relationships. In addition, internal drainage tests were made in four 1.5x1.5 m soil monoliths so as to find the hydraulic conductivity-water content relationships at different depths. On the assumption of similarity in porous media (verified in this study) all the results were analysed in terms of the theory of scaling factors. The data obtained in bare soil were then used as the basis for solving the stochastic equations for infiltration and drainage. The results show that, apart from satisfactory agreement, with the experiment, the mean solution obtained from the mean parameters (deterministic solution) is clearly different from the mean of the solutions (stochastic solution). These differences, as well as the variance, depend strongly on the variability of the soil, expressed here as the coefficient of variation of the scaling factors. This obviously calls in question the concept of equivalent porous media. (author)

  12. Life stories of people with rheumatoid arthritis who retired early: how gender and other contextual factors shaped their everyday activities, including paid work.

    Science.gov (United States)

    Stamm, T A; Machold, K P; Smolen, J; Prodinger, B

    2010-06-01

    The aim of the present study was to explore how contextual factors affect the everyday activities of women and men with rheumatoid arthritis (RA), as evident in their life stories. Fifteen people with RA, who had retired early due to the disease, were interviewed up to three times, according to a narrative biographic interview style. The life stories of the participants, which were reconstructed from the biographical data and from the transcribed 'told story' were analysed from the perspective of contextual factors, including personal and environmental factors. The rigour and accuracy of the analysis were enhanced by reflexivity and peer-review of the results. The life stories of the participants in this study reflected how contextual factors (such as gender, the healthcare system, the support of families and social and cultural values) shaped their everyday activities. In a society such as in Austria, which is based on traditional patriarchal values, men were presented with difficulties in developing a non-paid-work-related role. For women, if paid work had to be given up, they were more likely to engage in alternative challenging activities which enabled them to develop reflective skills, which in turn contributed to a positive and enriching perspective on their life stories. Health professionals may thus use some of the women's strategies to help men. Interventions by health professionals in people with RA may benefit from an approach sensitive to personal and environmental factors.

  13. Factors Related to Soil Transmitted Helminth Infection on Primary School Children

    Directory of Open Access Journals (Sweden)

    Liena Sofiana

    2018-01-01

    Full Text Available ABSTRACT Infeksi Soil Transmitted Helminth (STH is the third ranks of the top 10 common infectious diseases in the world with an incidence rate of about 1.4 billion per year. The incidence of STH in Indonesia is still quite high. This figure occurs in primary school students of 60-80%, while for all ages of 40% -60%. The purpose of this study was to determine factors related to STH infection in elementary school children at primary school of Moyudan Sleman. The type of research used was analytic observational with the cross-sectional design. The population in this study were all students of class I, II, and III in Moyudan Sleman primary school with total sampling technique of 60 respondents. Data analysis used chi-square. The test results showed that the habit of hand washing before eating (sig= 0.010; RP= 3.850, the habit of hand washing  after defecating(sig= 0.007; RP= 4.571, nail hygiene (sig= 0.179; RP= 2.138, the habit of wearing footwear (sig= 0.008; RP= 3.714, and bowel habits (sig= 0.004; RP= 4.000. It can be concluded that there was a relationship between hand washing before eating, hand washing after defecating, the habit of wearing footwear, bowel habits and STH infection on the students of Moyudan Sleman primary school but there was no relationship between nail hygiene and STH infection. ABSTRAK Infeksi Soil Transmitted Helminth (STH adalah penyakit yang menempati urutan ketiga dari 10 penyakit menular di dunia dengan tingkat kejadian sekitar 1,4 miliar per tahun. Insiden STH di Indonesia masih cukup tinggi. Angka tersebut terjadi pada siswa di sekolah dasar mencapai 60-80%, sedangkan untuk semua usia berkisar antara 40%-60%. Tujuan dari penelitian ini adalah untuk mengetahui faktor yang berhubungan dengan infeksi STH pada anak sekolah dasar di SD Negeri Moyudan Sleman. Penelitian ini adalah observasional analitik dengan rancangan cross sectional. Populasi dalam penelitian ini adalah semua siswa kelas I, II, dan III di SD Moyudan

  14. Lead (Pb) and other metals in New York City community garden soils: Factors influencing contaminant distributions

    International Nuclear Information System (INIS)

    Mitchell, Rebecca G.; Spliethoff, Henry M.; Ribaudo, Lisa N.; Lopp, Donna M.; Shayler, Hannah A.; Marquez-Bravo, Lydia G.; Lambert, Veronique T.; Ferenz, Gretchen S.; Russell-Anelli, Jonathan M.; Stone, Edie B.; McBride, Murray B.

    2014-01-01

    Urban gardens provide affordable fresh produce to communities with limited access to healthy food but may also increase exposure to lead (Pb) and other soil contaminants. Metals analysis of 564 soil samples from 54 New York City (NYC) community gardens found at least one sample exceeding health-based guidance values in 70% of gardens. However, most samples (78%) did not exceed guidance values, and medians were generally below those reported in NYC soil and other urban gardening studies. Barium (Ba) and Pb most frequently exceeded guidance values and along with cadmium (Cd) were strongly correlated with zinc (Zn), a commonly measured nutrient. Principal component analysis suggested that contaminants varied independently from organic matter and geogenic metals. Contaminants were associated with visible debris and a lack of raised beds; management practices (e.g., importing uncontaminated soil) have likely reduced metals concentrations. Continued exposure reduction efforts would benefit communities already burdened by environmental exposures. - Highlights: • We measured metals concentrations in soil from 54 New York City community gardens. • Pb and Ba exceeded health-based guidance values in 9%–12% of garden beds. • Pb concentrations were similar to those in other studies of urban garden soils. • Pb and Ba were associated with Zn, with visible debris, and with non-raised beds. • Observable details can help gardeners focus testing and exposure reduction efforts. - Pb and Ba, which exceeded health-based guidance values in 10–14% of NYC community garden soil samples, are associated with non-raised beds, visible debris, higher pH and Zn

  15. Factors affecting spatial variation of annual apparent Q₁₀ of soil respiration in two warm temperate forests.

    Directory of Open Access Journals (Sweden)

    Junwei Luan

    Full Text Available A range of factors has been identified that affect the temperature sensitivity (Q₁₀ values of the soil-to-atmosphere CO₂ flux. However, the factors influencing the spatial distribution of Q₁₀ values within warm temperate forests are poorly understood. In this study, we examined the spatial variation of Q₁₀ values and its controlling factors in both a naturally regenerated oak forest (OF and a pine plantation (PP. Q₁₀ values were determined based on monthly soil respiration (R(S measurements at 35 subplots for each stand from Oct. 2008 to Oct. 2009. Large spatial variation of Q₁₀ values was found in both OF and PP, with their respective ranges from 1.7 to 5.12 and from 2.3 to 6.21. In PP, fine root biomass (FR (R = 0.50, P = 0.002, non-capillary porosity (NCP (R = 0.37, P = 0.03, and the coefficients of variation of soil temperature at 5 cm depth (CV of T₅ (R = -0.43, P = 0.01 well explained the spatial variance of Q₁₀. In OF, carbon pool lability reflected by light fractionation method (LLFOC well explained the spatial variance of Q₁₀ (R = -0.35, P = 0.04. Regardless of forest type, LLFOC and FR correlation with the Q₁₀ values were significant and marginally significant, respectively; suggesting a positive relationship between substrate availability and apparent Q₁₀ values. Parameters related to gas diffusion, such as average soil water content (SWC and NCP, negatively or positively explained the spatial variance of Q₁₀ values. Additionally, we observed significantly higher apparent Q₁₀ values in PP compared to OF, which might be partly attributed to the difference in soil moisture condition and diffusion ability, rather than different substrate availabilities between forests. Our results suggested that both soil chemical and physical characters contributed to the observed large Q₁₀ value variation.

  16. Soil erosion and causative factors at Vandenberg Air Force Base, California

    Science.gov (United States)

    Butterworth, Joel B.

    1988-01-01

    Areas of significant soil erosion and unvegetated road cuts were identified and mapped for Vandenberg Air Force Base. One hundred forty-two eroded areas (most greater than 1.2 ha) and 51 road cuts were identified from recent color infrared aerial photography and ground truthed to determine the severity and causes of erosion. Comparison of the present eroded condition of soils (as shown in the 1986 photography) with that in historical aerial photography indicates that most erosion on the base took place prior to 1928. However, at several sites accelerated rates of erosion and sedimentation may be occurring as soils and parent materials are eroded vertically. The most conspicuous erosion is in the northern part of the base, where severe gully, sheet, and mass movement erosion have occurred in soils and in various sedimentary rocks. Past cultivation practices, compounded by highly erodible soils prone to subsurface piping, are probably the main causes. Improper range management practices following cultivation may have also increased runoff and erosion. Aerial photography from 1986 shows that no appreciable headward erosion or gully sidewall collapse have occurred in this area since 1928.

  17. batman Interacts with polycomb and trithorax group genes and encodes a BTB/POZ protein that is included in a complex containing GAGA factor.

    Science.gov (United States)

    Faucheux, M; Roignant, J-Y; Netter, S; Charollais, J; Antoniewski, C; Théodore, L

    2003-02-01

    Polycomb and trithorax group genes maintain the appropriate repressed or activated state of homeotic gene expression throughout Drosophila melanogaster development. We have previously identified the batman gene as a Polycomb group candidate since its function is necessary for the repression of Sex combs reduced. However, our present genetic analysis indicates functions of batman in both activation and repression of homeotic genes. The 127-amino-acid Batman protein is almost reduced to a BTB/POZ domain, an evolutionary conserved protein-protein interaction domain found in a large protein family. We show that this domain is involved in the interaction between Batman and the DNA binding GAGA factor encoded by the Trithorax-like gene. The GAGA factor and Batman codistribute on polytene chromosomes, coimmunoprecipitate from nuclear embryonic and larval extracts, and interact in the yeast two-hybrid assay. Batman, together with the GAGA factor, binds to MHS-70, a 70-bp fragment of the bithoraxoid Polycomb response element. This binding, like that of the GAGA factor, requires the presence of d(GA)n sequences. Together, our results suggest that batman belongs to a subset of the Polycomb/trithorax group of genes that includes Trithorax-like, whose products are involved in both activation and repression of homeotic genes.

  18. New insight in the derivation of amplification factor by taking into account soil parameters. In : Proceedings of the 16th World Conference on Earthquake Engineering

    OpenAIRE

    ZENDAGUI, Djawad; STAMBOULI BOUDGHENE, Ahmed; BARD, Pierre Yves; DERRAS, Boumédiène

    2017-01-01

    It is currently admitted that the amplification factor (AF) is one of the best tools to describe site effects. AF depends on soil parameters that are derived from the geometrical and mechanical soil properties of the soil profile. Thus, it is important to identify which soil parameters shape the form of the AF. The aim of this paper is to measure the effects of various site parameters on the variation of AF. As the problem is highly complex, a tool using the GRNN (Generalized Regression Neura...

  19. Soil pH Is the Primary Factor Correlating With Soil Microbiome in Karst Rocky Desertification Regions in the Wushan County, Chongqing, China

    Directory of Open Access Journals (Sweden)

    Daihua Qi

    2018-05-01

    Full Text Available Karst rocky desertification (KRD is a process of land degradation, which causes desert-like landscapes, deconstruction of endemic biomass, and declined soil quality. The relationship of KRD progression with above-ground communities (e.g. vegetation and animal is well-studied. Interaction of soil desertification with underground communities, such as soil microbiome, however, is vastly unknown. This study characterizes change in soil bacterial community in response to KRD progression. Soil bacterial communities were surveyed by deep sequencing of 16S amplicons. Eight soil properties, pH, soil organic matter (SOM, total and available nitrogen (TN and AN, total and available phosphorus (TP and AP, and total and available potassium (TK and AK, were measured to assess soil quality. We find that the overall soil quality decreases along with KRD progressive gradient. Soil bacterial community compositions are distinguishingly different in KRD stages. The richness and diversity in bacterial community do not significantly change with KRD progression although a slight increase in diversity was observed. A slight decrease in richness was seen in SKRD areas. Soil pH primarily correlates with bacterial community composition. We identified a core microbiome for KRD soils consisting of; Acidobacteria, Alpha-Proteobacteria, Planctomycetes, Beta-Proteobacteria, Actinobacteria, Firmicutes, Delta-Proteobacteria, Chloroflexi, Bacteroidetes, Nitrospirae, and Gemmatimonadetes in this study. Phylum Cyanobacteria is significantly abundant in non-degraded soils, suggesting that Cyanobacterial activities might be correlated to soil quality. Our results suggest that Proteobacteria are sensitive to changes in soil properties caused by the KRD progression. Alpha- and beta-Proteobacteria significantly predominated in SKRD compared to NKRD, suggesting that Proteobacteria, along with many others in the core microbiome (Acidobacteria, Actinobacteria, Firmicutes, and Nitrospirae

  20. Alaskan soil carbon stocks: spatial variability and dependence on environmental factors

    Directory of Open Access Journals (Sweden)

    U. Mishra

    2012-09-01

    Full Text Available The direction and magnitude of soil organic carbon (SOC changes in response to climate change depend on the spatial and vertical distributions of SOC. We estimated spatially resolved SOC stocks from surface to C horizon, distinguishing active-layer and permafrost-layer stocks, based on geospatial analysis of 472 soil profiles and spatially referenced environmental variables for Alaska. Total Alaska state-wide SOC stock was estimated to be 77 Pg, with 61% in the active-layer, 27% in permafrost, and 12% in non-permafrost soils. Prediction accuracy was highest for the active-layer as demonstrated by highest ratio of performance to deviation (1.5. Large spatial variability was predicted, with whole-profile, active-layer, and permafrost-layer stocks ranging from 1–296 kg C m−2, 2–166 kg m−2, and 0–232 kg m−2, respectively. Temperature and soil wetness were found to be primary controllers of whole-profile, active-layer, and permafrost-layer SOC stocks. Secondary controllers, in order of importance, were found to be land cover type, topographic attributes, and bedrock geology. The observed importance of soil wetness rather than precipitation on SOC stocks implies that the poor representation of high-latitude soil wetness in Earth system models may lead to large uncertainty in predicted SOC stocks under future climate change scenarios. Under strict caveats described in the text and assuming temperature changes from the A1B Intergovernmental Panel on Climate Change emissions scenario, our geospatial model indicates that the equilibrium average 2100 Alaska active-layer depth could deepen by 11 cm, resulting in a thawing of 13 Pg C currently in permafrost. The equilibrium SOC loss associated with this warming would be highest under continuous permafrost (31%, followed by discontinuous (28%, isolated (24.3%, and sporadic (23.6% permafrost areas. Our high-resolution mapping of soil carbon stock reveals the

  1. Geostatistical modelling of soil-transmitted helminth infection in Cambodia: do socioeconomic factors improve predictions?

    Science.gov (United States)

    Karagiannis-Voules, Dimitrios-Alexios; Odermatt, Peter; Biedermann, Patricia; Khieu, Virak; Schär, Fabian; Muth, Sinuon; Utzinger, Jürg; Vounatsou, Penelope

    2015-01-01

    Soil-transmitted helminth infections are intimately connected with poverty. Yet, there is a paucity of using socioeconomic proxies in spatially explicit risk profiling. We compiled household-level socioeconomic data pertaining to sanitation, drinking-water, education and nutrition from readily available Demographic and Health Surveys, Multiple Indicator Cluster Surveys and World Health Surveys for Cambodia and aggregated the data at village level. We conducted a systematic review to identify parasitological surveys and made every effort possible to extract, georeference and upload the data in the open source Global Neglected Tropical Diseases database. Bayesian geostatistical models were employed to spatially align the village-aggregated socioeconomic predictors with the soil-transmitted helminth infection data. The risk of soil-transmitted helminth infection was predicted at a grid of 1×1km covering Cambodia. Additionally, two separate individual-level spatial analyses were carried out, for Takeo and Preah Vihear provinces, to assess and quantify the association between soil-transmitted helminth infection and socioeconomic indicators at an individual level. Overall, we obtained socioeconomic proxies from 1624 locations across the country. Surveys focussing on soil-transmitted helminth infections were extracted from 16 sources reporting data from 238 unique locations. We found that the risk of soil-transmitted helminth infection from 2000 onwards was considerably lower than in surveys conducted earlier. Population-adjusted prevalences for school-aged children from 2000 onwards were 28.7% for hookworm, 1.5% for Ascaris lumbricoides and 0.9% for Trichuris trichiura. Surprisingly, at the country-wide analyses, we did not find any significant association between soil-transmitted helminth infection and village-aggregated socioeconomic proxies. Based also on the individual-level analyses we conclude that socioeconomic proxies might not be good predictors at an

  2. Soil tension mediates isotope fractionation during soil water evaporation

    Science.gov (United States)

    Gaj, Marcel; McDonnell, Jeffrey

    2017-04-01

    Isotope tracing of the water cycle is increasing in its use and usefulness. Many new studies are extracting soil waters and relating these to streamflow, groundwater recharge and plant transpiration. Nevertheless, unlike isotope fractionation factors from open water bodies, soil water fractionation factors are poorly understood and until now, only empirically derived. In contrast to open water evaporation where temperature, humidity and vapor pressure gradient define fractionation (as codified in the well-known Craig and Gordon model), soil water evaporation includes additionally, fractionation by matrix effects. There is yet no physical explanation of kinetic and equilibrium fraction from soil water within the soil profile. Here we present a simple laboratory experiment with four admixtures of soil grain size (from sand to silt to clay). Oven-dried samples were spiked with water of known isotopic composition at different soil water contents. Soils were then stored in sealed bags and the headspace filled with dry air and allowed to equilibrate for 24hours. Isotopic analysis of the headspace vapor was done with a Los Gatos Inc. water vapor isotope analyzer. Soil water potential of subsamples were measured with a water potential meter. We show for the first time that soil tension controls isotope fractionation in the resident soil water. Below a Pf 3.5 the δ-values of 18O and 2H of the headspace vapor is more positive and increases with increasing soil water potential. Surprisingly, we find that the relationship between soil tension and equilibrium fractionation is independent of soil type. However, δ-values of each soil type plot along a distinct evaporation line. These results indicate that equilibrium fractionation is affected by soil tension in addition to temperature. Therefore, at high soil water tension (under dry conditions) equilibrium fractionation is not consistent with current empirical formulations that ignore these effects. These findings may have

  3. Risk Factors for Pressure Ulcers Including Suspected Deep Tissue Injury in Nursing Home Facility Residents: Analysis of National Minimum Data Set 3.0.

    Science.gov (United States)

    Ahn, Hyochol; Cowan, Linda; Garvan, Cynthia; Lyon, Debra; Stechmiller, Joyce

    2016-04-01

    To provide information on risk factors associated with pressure ulcers (PrUs), including suspected deep tissue injury (sDTI), in nursing home residents in the United States. This continuing education activity is intended for physicians and nurses with an interest in skin and wound care. After participating in this educational activity, the participant should be better able to:1. Examine the literature related to risk factors for the development of PrUs.2. Compare risk factors associated with the prevalence of PrUs and sDTI from the revised Minimum Data Set 3.0 2012 using a modified Defloor's conceptual model of PrUs as a theoretical framework. This study aims to characterize and compare risk factors associated with pressure ulcers (PrUs), including suspected deep tissue injury (sDTI), in nursing home (NH) residents in the United States. Secondary analysis of the 2012 Minimum Data Set (MDS 3.0). Medicare- or Medicaid-certified NHs in the United States. Nursing home residents (n = 2,936,146) 18 years or older with complete PrU data, who received comprehensive assessments from January to December 2012. Pressure ulcer by stage was the outcome variable. Explanatory variables (age, gender, race and ethnicity, body mass index, skin integrity, system failure, disease, infection, mobility, and cognition) from the MDS 3.0 were aligned with the 4 elements of Defloor's conceptual model: compressive forces, shearing forces, tissue tolerance for pressure, and tissue tolerance for oxygen. Of 2,936,146 NH residents who had complete data for PrU, 89.9% had no PrU; 8.4% had a Stage 2, 3, or 4 or unstagable PrU; and 1.7% had an sDTI. The MDS variables corresponding to the 4 elements of Defloor's model were significantly predictive of both PrU and sDTI. Black residents had the highest risk of any-stage PrU, and Hispanic residents had the highest risk of sDTI. Skin integrity, system failure, infection, and disease risk factors had larger effect sizes for sDTI than for other PrU stages

  4. Response of root fungi in Pisum sativum to plant and soil environmental factors

    DEFF Research Database (Denmark)

    Yu, Lingling

    and nutritional status of the plant and soil environments. However, limited information is available about the richness and composition of most of these root-associated fungi as studies of fungal communities remain a challenge because of below-ground high taxonomic and ecological diversity. In the present study......; thus obligate biotrophic fungi and saprotrophic fungi were markedly increased with organic fertilizer dosages, while root pathogenic fungi were decreased with organic amendments. In conclusion, the present work has shown that root-associated fungal community structure relate to plant and soil...... environmental factors. The obtained knowledge from this study can provide novel information of communities of root-associated fungi; thus improving the basic understanding of plant-root fungi-environment interactions in agroecosystems....

  5. Unveiling soil degradation and desertification risk in the Mediterranean basin: a data mining analysis of the relationships between biophysical and socioeconomic factors in agro-forest landscapes

    NARCIS (Netherlands)

    Salvati, L.; Kosmas, C.; Kairis, O.; Karavitis, C.; Hessel, R.; Ritsema, C.J.

    2015-01-01

    Soil degradation and desertification processes in the Mediterranean basin reflect the interplay between environmental and socioeconomic drivers. An approach to evaluate comparatively the multiple relationships between biophysical variables and socioeconomic factors is illustrated in the present

  6. Health effects of an increased protein intake on kidney function and colorectal cancer risk factors, including the role of animal and plant protein sources – the PREVIEW project

    DEFF Research Database (Denmark)

    Møller, Grith

    intake, including the role of animal and plant protein in pre-diabetic, overweight or obese individuals on health outcomes: markers of kidney function and putative risk factors for colorectal cancer as well as insulin sensitivity and kidney function in healthy individuals. The thesis is based on PREVIEW......, especially plant protein, on insulin sensitivity and kidney function. In paper II, the aim of the study was to assess the effect after one year of a higher protein intake on kidney function, measured by in creatinine clearance. This was investigated in pre-diabetic older adults based on a sub-group of 310...... pre-diabetic individuals included in the PREVIEW RCT. We found that a higher protein intake was associated with a significant increase in urea to creatinine ratio and serum urea after one year. There were no associations between increased protein intake and creatinine clearance, estimated glomerular...

  7. Field evaluation of support practice (P-factor) for stone walls to control soil erosion in an arid area (Northern Jordan)

    Science.gov (United States)

    Gharaibeh, Mamoun; Albalasmeh, Ammar

    2017-04-01

    Stone walls have been adopted for long time to control water erosion in many Mediterranean countries. In soil erosion equations, the support practice factor (P-factor) for stone walls has not been fully studied or rarely taken into account especially in semi-arid and arid regions. Field studies were conducted to evaluate the efficiency of traditional stone walls and to quantify soil erosion in six sites in north and northeastern Jordan. Initial estimates using the Universal Soil Loss Equation (USLE) showed that rainfall erosion was reduced by 65% in areas where stone walls are present. Annual soil loss ranged from 5 to 15 t yr-1. The mean annual soil loss in the absence of stone walls ranged from 10-60 t ha-1 with an average value of 35 t ha-1. Interpolating the slope of thickness of A horizon provided an average initial estimate of 0.3 for P value.

  8. Soil-to-plant transfer factors of trace and major elements in rice plant (Oryza Sativa) at Kalpakkam

    International Nuclear Information System (INIS)

    Sreedevi, K.R.; Rajaram, S.; Thulasi Brindha, J.; Venkataraman, S.; Hegde, A.G.

    2011-01-01

    The objective of this study was to evaluate the distribution of trace and major elements in rice plant (Oryza Sativa) which is the staple diet of the public at Kalpakkam. The transfer factor from soil to various parts of plant was also studied. Trace and major elements such as Fe, Mn, Zn, Co, Cu, Ni, Cr, Cd, Pb , Sr, K, Ca and Mg were selected based on their role in nutrition and also to study the behaviour of their radioactive counterparts. Among the trace elements Fe concentration was observed to be maximum in soil, the mean value of which was 18394 mg/kg dry wt. Cadmium concentration was observed to be minimum with the mean value of 2 mg/kg dry wt. The maximum and minimum concentration observed in the rice grain were due to Zn and Cd and the values were found to be 9 and 0.044 mg/kg dry wt, respectively. In the stem and leaves part the maximum and minimum concentration was due to Fe and Cd and the values were found to be 26.8 and 0.12 mg/kg dry wt. Similarly in the root part Fe and Cd concentrations were found to be maximum and minimum, respectively. Among the different parts of the rice plant, trace elements concentration in root was maximum and in stem and leaves major elements concentration was maximum. Transfer factor from soil to plant parts was computed. In general, the transfer factor was maximum in root, followed by stem and leaves and grain for trace elements. The transfer factor computed for whole rice plant was maximum for Zn and minimum for Sr which is a significant observation from radiological point of view. (author)

  9. Lateral gas transport in soil adjacent to an old landfill: factors governing gas migration

    DEFF Research Database (Denmark)

    Christophersen, Mette; Kjeldsen, Peter

    2001-01-01

    was observed. There was a good correlation between pressure above the barometric pressure and the methane concentration in the soil, indicating that advective flow was the controlling process. This was confirmed by calculations. Diurnal measurement during a drop in barometric pressure showed that lateral...

  10. Environmental factors at different spatial scales governing soil fauna community patterns in fragmented forests.

    NARCIS (Netherlands)

    Martins da Silva, P.; Berg, M.P.; Serrano, A.R.M.; Dubs, F.; Sousa, J.P.

    2012-01-01

    Spatial and temporal changes in community structure of soil organisms may result from a myriad of processes operating at a hierarchy of spatial scales, from small-scale habitat conditions to species movements among patches and large-sale landscape features. To disentangle the relative importance of

  11. Using machine learning to predict the impact of agricultural factors on communities of soil microarthropods

    DEFF Research Database (Denmark)

    Dem?ar, D.; D?eroski, S.; Krogh, P. H.

    2005-01-01

    With the newly arisen ecological awareness in the agriculture the sustainable use and development of the land is getting more important. With the sustainable use of soil in mind, we are developing a decision support system that helps making decisions on managing agricultural systems and is able t...

  12. Factors affecting soil fauna feeding activity in a fragmented lowland temperate deciduous woodland.

    Science.gov (United States)

    Simpson, Jake E; Slade, Eleanor; Riutta, Terhi; Taylor, Michele E

    2012-01-01

    British temperate broadleaf woodlands have been widely fragmented since the advent of modern agriculture and development. As a result, a higher proportion of woodland area is now subject to edge effects which can alter the efficiency of ecosystem functions. These areas are particularly sensitive to drought. Decomposition of detritus and nutrient cycling are driven by soil microbe and fauna coactivity. The bait lamina assay was used to assess soil fauna trophic activity in the upper soil horizons at five sites in Wytham Woods, Oxfordshire: two edge, two intermediate and one core site. Faunal trophic activity was highest in the core of the woodland, and lowest at the edge, which was correlated with a decreasing soil moisture gradient. The efficiency of the assay was tested using four different bait flavours: standardised, ash (Fraxinus excelsior L.), oak (Quercus robur L.), and sycamore (Acer pseudoplatanus L.). The standardised bait proved the most efficient flavour in terms of feeding activity. This study suggests that decomposition and nutrient cycling may be compromised in many of the UK's small, fragmented woodlands in the event of drought or climate change.

  13. Factors affecting soil fauna feeding activity in a fragmented lowland temperate deciduous woodland.

    Directory of Open Access Journals (Sweden)

    Jake E Simpson

    Full Text Available British temperate broadleaf woodlands have been widely fragmented since the advent of modern agriculture and development. As a result, a higher proportion of woodland area is now subject to edge effects which can alter the efficiency of ecosystem functions. These areas are particularly sensitive to drought. Decomposition of detritus and nutrient cycling are driven by soil microbe and fauna coactivity. The bait lamina assay was used to assess soil fauna trophic activity in the upper soil horizons at five sites in Wytham Woods, Oxfordshire: two edge, two intermediate and one core site. Faunal trophic activity was highest in the core of the woodland, and lowest at the edge, which was correlated with a decreasing soil moisture gradient. The efficiency of the assay was tested using four different bait flavours: standardised, ash (Fraxinus excelsior L., oak (Quercus robur L., and sycamore (Acer pseudoplatanus L.. The standardised bait proved the most efficient flavour in terms of feeding activity. This study suggests that decomposition and nutrient cycling may be compromised in many of the UK's small, fragmented woodlands in the event of drought or climate change.

  14. Study of the factors affecting the sorption and fixation of radiocesium on some egyptian soil sediments

    International Nuclear Information System (INIS)

    Kamel, N.H.M.

    1996-01-01

    The present work with studying the use of egyptian soil samples for the sorption and fixation of low level activity wastes containing Cs-134 isotope. This radioactive isotope is one of the most important radionuclides found in low and intermediate level waste streams, as a fission product. The sorption process of radiocesium by the soil samples is governed by a number of variables such as the physical, mineralogical and chemical composition of the samples, effect of carrier ion concentrations,contact time, saturation with different cations and heat treatment of the soil samples . The effect of these variables had been investigated. The sorption behavior of Cs has been explained by applying Freundlich, Langmuir and Dubinin-Raduskevich equations. sorption of Cs can also be described on a laboratory time scale by more than one kinetic process. About 30 soil samples, supplied from the institute of metallurgy and the geological survey administration in egypt, were brought from different locations from the egyptian desert. These samples represent areas from Fayom, Wadi El-Rayan, Cairo Fayom Road, Quasr El-Sagha, North of the Eastern desert (egyptian vermiculite) and cairo - alexandria desert road(at 46 - 48 km from cairo). A pure german sample was used as a reference smectite clay for comparing the physical, chemical and mineralogical properties

  15. Evaluation of the spatial patterns and risk factors, including backyard pigs, for classical swine fever occurrence in Bulgaria using a Bayesian model

    Directory of Open Access Journals (Sweden)

    Beatriz Martínez-López

    2014-05-01

    Full Text Available The spatial pattern and epidemiology of backyard pig farming and other low bio-security pig production systems and their role in the occurrence of classical swine fever (CSF is described and evaluated. A spatial Bayesian model was used to explore the risk factors, including human demographics, socioeconomic and environmental factors. The analyses were performed for Bulgaria, which has a large number of backyard farms (96% of all pig farms in the country are classified as backyard farms, and it is one of the countries for which both backyard pig and farm counts were available. Results reveal that the high-risk areas are typically concentrated in areas with small family farms, high numbers of outgoing pig shipments and low levels of personal consumption (i.e. economically deprived areas. Identification of risk factors and high-risk areas for CSF will allow to targeting risk-based surveillance strategies leading to prevention, control and, ultimately, elimination of the disease in Bulgaria and other countries with similar socio-epidemiological conditions.

  16. A STUDY OF CHINESE YUAN (RMB APPRECIATION ACCOMPANYING WITH OTHERS FACTORS INCLUDING FOREIGN DIRECT INVESTMENT (FDI AND THEIR EFFECT ON CHINA ECONOMY

    Directory of Open Access Journals (Sweden)

    Ping-fu (Brian LAI

    2014-07-01

    Full Text Available The Chinese Yuan (RMB has been on the trend of appreciation over the last decade, and such a trend will likely be continuing for some years over the next decade. According to some scholars in their published literatures, the appreciation of RMB, the influx of Foreign Direct Investment (FDI has been ongoing accompanying the sustained growing economy in mainland China over the past decade. It is believed that the China economy has an implication from some significant factors including appreciation of RMB, interest rate of RMB, inflation and continuous increase of FDI for the next several years. The present study aims to provide an emphasis on investigation into effect on China economy as a result of appreciation of RMB and FDI together with some other factors, and to provide an outlook on the economy in China for the coming decades. First, a review was carried on relevant background information and development history of RMB and FDI. There are many reasons and factors behind leading to the sustained growth in the economy in China in the last decade and such effects were in coverage in the literature review. An overview of the development of RMB exchange mechanism, and other variables including (1 RMB exchange rate, (2 China interest rate, (3 Foreign Direct Investment (FDI, (4 Trade Balance of China, (5 Annual Inflation rate in China, (6 Energy Consumption in China, (7 Foreign Exchange Reserve in China, (8 China wages, (9 China External Debt and (10 China Consumer Price Index, which may have effect on the growth of the economy in China is covered in the literature review conducted in Chapter 2.

  17. Soil-to-Rice Seeds Transfer Factors of Radioiodine and Technetium for Paddy Fields around the Radioactive-Waste Disposal Site in Gyeongju

    International Nuclear Information System (INIS)

    Choi, Yong Ho; Lim, Kwang Muk; Jun, In; Park, Doo Won; Keum, Dong Kwon; Han, Moon Hee

    2010-01-01

    Radiotracer experiments were performed over two years using pot cultures in a greenhouse to investigate soil-torice seeds transfer factors of radioiodine and technetium for paddy fields around the radioactive-waste disposal site in Gyeongju. Before transplanting rice seedlings, the top about 20 cm soils were thoroughly mixed with 125 I (2007) and 99 Tc (2008), and the pots were irrigated to simulate flooded rice fields. Transfer factors were determined as the ratios of the radionuclide concentrations in dry rice seeds (brown rice) to those in dry soils. Transfer factors of radioiodine and technetium were in the ranges of 1.1 x 10 -3 ∼ 6.4 x 10 -3 (three soils) and 5.4 x 10 -4 ∼ 2.5 x 10 -3 (four soils), respectively, for different soils. It seems that the differences in the clay content among soils played a more important role for such variations than those in the organic matter content and pH. As the representative values of radioiodine and technetium transfer factors for rice seeds, 2.9 x 10 -3 and 1.1 x 10 -3 , respectively, were proposed. In order to obtain more highly representative values in the future, investigations for the sites of interest need to be carried out continuously

  18. Concentrations of polycyclic aromatic hydrocarbons in New York City community garden soils: Potential sources and influential factors.

    Science.gov (United States)

    Marquez-Bravo, Lydia G; Briggs, Dean; Shayler, Hannah; McBride, Murray; Lopp, Donna; Stone, Edie; Ferenz, Gretchen; Bogdan, Kenneth G; Mitchell, Rebecca G; Spliethoff, Henry M

    2016-02-01

    A total of 69 soil samples from 20 community gardens in New York City (New York, USA) were collected and analyzed for 23 polycyclic aromatic hydrocarbons (PAHs) and black carbon. For each garden, samples were collected from nongrowing areas (non-bed) and from vegetable-growing beds, including beds with and without visible sources of PAHs. The sum of the US Environmental Protection Agency's 16 priority PAHs ranged up to 150 mg/kg, and the median (5.4 mg/kg) and mean (14.2 mg/kg) were similar to those previously reported for urban areas in the northeast United States. Isomer ratios indicated that the main sources of PAHs were petroleum, coal, and wood combustion. The PAH concentrations were significantly and positively associated with black carbon and with modeled air PAH concentrations, suggesting a consistent relationship between historical deposition of atmospheric carbon-adsorbed PAHs and current PAH soil concentrations. Median PAH soil concentration from non-bed areas was higher (7.4 mg/kg) than median concentration from beds in the same garden (4.0 mg/kg), and significantly higher than the median from beds without visible sources of PAHs (3.5 mg/kg). Median PAH concentration in beds from gardens with records of soil amendments was 58% lower compared with beds from gardens without those records. These results suggest that gardening practices in garden beds without visible sources of PAHs contribute to reduce PAH soil concentrations. © 2015 SETAC.

  19. Microbial Ecology of Soil Aggregation in Agroecosystems

    Science.gov (United States)

    Hofmockel, K. S.; Bell, S.; Tfailly, M.; Thompson, A.; Callister, S.

    2017-12-01

    Crop selection and soil texture influence the physicochemical attributes of the soil, which structures microbial communities and influences soil C cycling storage. At the molecular scale, microbial metabolites and necromass alter the soil environment, which creates feedbacks that influence ecosystem functions, including soil C accumulation. By integrating lab to field studies we aim to identify the molecules, organisms and metabolic pathways that control carbon cycling and stabilization in bioenergy soils. We investigated the relative influence of plants, microbes, and minerals on soil aggregate ecology at the Great Lakes Bioenergy Research experiment. Sites in WI and MI, USA have been in corn and switchgrass cropping systems for a decade. By comparing soil aggregate ecology across sites and cropping systems we are able to test the relative importance of plant, microbe, mineral influences on soil aggregate dynamics. Soil microbial communities (16S) differ in diversity and phylogeny among sites and cropping systems. FT-ICR MS revealed differences in the molecular composition of water-soluble fraction of soil organic matter for cropping systems and soil origin for both relative abundance of assigned formulas and biogeochemical classes of compounds. We found the degree of aggregation, measured by mean weighted diameter of aggregate fractions, is influenced by plant-soil interactions. Similarly, the proportion of soil aggregate fractions varied by both soil and plant factors. Differences in aggregation were reflected in differences in bacterial, but not fungal community composition across aggregate fractions, within each soil. Scanning electron microscopy revealed stark differences in mineral-organic interactions that influence the microbial niche and the accessibility of substrates within the soil. The clay soils show greater surface heterogeneity, enabling interactions with organic fraction of the soil. This is consistent with molecular data that reveal differences

  20. Escherichia coli Contamination across Multiple Environmental Compartments (Soil, Hands, Drinking Water, and Handwashing Water) in Urban Harare: Correlations and Risk Factors.

    Science.gov (United States)

    Navab-Daneshmand, Tala; Friedrich, Max N D; Gächter, Marja; Montealegre, Maria Camila; Mlambo, Linn S; Nhiwatiwa, Tamuka; Mosler, Hans-Joachim; Julian, Timothy R

    2018-03-01

    Escherichia coli pathotypes (i.e., enteropathogenic and enterotoxigenic) have been identified among the pathogens most responsible for moderate-to-severe diarrhea in low- and middle-income countries (LMICs). Pathogenic E. coli are transmitted from infected human or animal feces to new susceptible hosts via environmental reservoirs such as hands, water, and soil. Commensal E. coli , which includes nonpathogenic E. coli strains, are widely used as fecal bacteria indicator, with their presence associated with increased likelihood of enteric pathogens and/or diarrheal disease. In this study, we investigated E. coli contamination in environmental reservoirs within households ( N = 142) in high-population density communities of Harare, Zimbabwe. We further assessed the interconnectedness of the environmental compartments by investigating associations between, and household-level risk factors for, E. coli contamination. From the data we collected, the source and risk factors for E. coli contamination are not readily apparent. One notable exception is the presence of running tap water on the household plot, which is associated with significantly less E. coli contamination of drinking water, handwashing water, and hands after handwashing. In addition, E. coli levels on hands after washing are significantly associated with handwashing water contamination, hand contamination before washing, and diarrhea incidence. Finally, we observed that animal ownership increases E. coli contamination in soil, and E. coli in soil are correlated with contamination on hands before washing. This study highlights the complexity of E. coli contamination in household environments within LMICs. More, larger, studies are needed to better identify sources and exposure pathways of E. coli -and enteric pathogens generally-to identify effective interventions.

  1. The rhizosphere zoo: An overview of plant-associated communities of microorganisms, including phages, bacteria, archaea, and fungi, and some of their structuring factors

    NARCIS (Netherlands)

    Buée, M.; Boer, de W.; Martin, F.; Overbeek, van L.S.; Jurkevitch, E.

    2009-01-01

    Rhizosphere microorganisms have two faces, like Janus the Roman god of gates and doors who symbolizes changes and transitions, from one condition to another. One face looks at the plant root, the other sees the soil. The ears and the nose sense the other gods around and the mouths are wide open,

  2. Quantitative Analysis of the Factors Influencing Soil Heavy Metal Lateral Migration in Rainfalls Based on Geographical Detector Software: A Case Study in Huanjiang County, China

    Directory of Open Access Journals (Sweden)

    Pengwei Qiao

    2017-07-01

    Full Text Available Quantitative analysis of the factors influencing heavy metal migration could be useful for controlling heavy metal migration. In this paper, a geographical detector was used to calculate the contributions of and interactions among factors in Huanjiang County, South China, covering an area of 273 km2. In this paper, nine factors were analyzed. The results showed that, among these factors, soil type was the main factor influencing the migration of As, Pb and Cd; the other eight factors did not have big differences and were lower than soil type. In addition, there were obvious synergistic effects between the soil type and concentration of water-soluble heavy metals (CWS and the concentration of water-insoluble heavy metals (CWI and NDVI. Therefore, these factors of the study area were especially focused on. Furthermore, the results of the key factor identification and the high-risk region identification in the nine factors were reliable, based on the geographical detector software. Therefore, the geographical detector software could be used as an effective tool to quantitatively analyze the contribution of the factors, and identify the high-risk regions for the factors influencing soil heavy metal lateral migration in rainfalls.

  3. Regional factors rather than forest type drive the community structure of soil living oribatid mites (Acari, Oribatida).

    Science.gov (United States)

    Erdmann, Georgia; Scheu, Stefan; Maraun, Mark

    2012-06-01

    Most European forests are managed by humans. However, the manner and intensity of management vary. While the effect of forest management on above-ground communities has been investigated in detail, effects on the below-ground fauna remain poorly understood. Oribatid mites are abundant microarthropods in forest soil and important decomposers in terrestrial ecosystems. Here, we investigated the effect of four forest types (i.e., managed coniferous forests; 30 and 70 years old managed beech forests; natural beech forests) on the density, diversity and community structure of oribatid mites (Acari). The study was replicated at three regions in Germany: the Swabian Alb, the Hainich and the Schorfheide. To relate changes in oribatid mite community structure to environmental factors, litter mass, pH, C and N content of litter, fine roots and C content of soil were measured. Density of oribatid mites was highest in the coniferous forests and decreased in the order 30 years old, 70 years old, and natural beech forests. Mass of the litter layer and density of oribatid mites were strongly correlated indicating that the litter layer is an important factor regulating oribatid mite densities. Diversity of oribatid mites was little affected by forest type indicating that they harbor similar numbers of niches. Species composition differed between the forest types, suggesting different types of niches. The community structure of oribatid mites differed more strongly between the three regions than between the forest types indicating that regional factors are more important than effects associated with forest type.

  4. Soil-to-plant transfer factors of technetium-99 for various plants collected in the Chernobyl area

    International Nuclear Information System (INIS)

    Tagami, Keiko; Uchida, Shigeo

    2005-01-01

    Technetium-99 is thought to be highly soluble and rarely adsorbed onto soil, however, its mobility under natural environment is not well known because its scarcity and low levels in environmental samples has limited the available data. In this study, we determined 99 Tc contents in 27 plant samples collected in three forest sites in 1994 and 1995 around the Chernobyl area to obtain transfer factors (TFs) of Tc in the soil-plant system under environmental conditions. The samples were leaves of raspberry, strawberry and pink plants, black alder, birch, cowberry and oak trees, and ferns. After chemical separation, 99 Tc in the sample was measured by ICP-MS. Tc-95m was used as a yield tracer and the total recovery ranged from 0.48 to 0.92 with an average of 0.76. The determined 99 Tc concentrations in plants ranged from -1 (dry weight basis). TF values ranged from 99 Tc contents of the soil organic layers. The highest TF was found in the leaves of raspberry plants. The observed TFs were much lower than the values of 8.1 - 2600 compiled by IAEA for grass, fodder and leafy vegetables. (author)

  5. Erosivity factor in the Universal Soil Loss Equation estimated from Finnish rainfall data

    Directory of Open Access Journals (Sweden)

    Maximilian Posch

    1993-07-01

    Full Text Available Continuous rainfall data recorded for many years at 8 stations in Finland were used to estimate rainfall erosivity, a quantity needed for soil loss predictions with the Universal Soil Loss Equation (USLE. The obtained erosivity values were then used to determine the 2 parameters of a power-law function describing the relationship between daily precipitation and erosivity. This function is of importance in erosion modeling at locations where no breakpoint rainfall data are available. The parameters of the power-law were estimated both by linear regression of the log-transformed data and by non-linear least-square fitting of the original data. Results indicate a considerable seasonal (monthly variation of the erosivity, whereas the spatial variation over Finland is rather small.

  6. The Effects of Environmental Factors on Biological Remediation of Petroleum Hydrocarbon Contaminated Soil

    Directory of Open Access Journals (Sweden)

    Mohammad reza Moslemi

    2005-09-01

    Full Text Available Among the consequences of discharging industrial wastes to land and water bodies, is the widespread accumulation and migration of toxic chemical mixtures in soil and groundwater resources. It is believed that the accumulation of contaminants in the environment constitutes a serious threat to ecological and human health. Bioremediation is an effective measure in dealing with such contaminations particularly those from petroleum hydrocarbon sources; moreover bioremediation is emerging as a promising technology for the treatment of soil and groundwater contamination. Therefore the goal of this study is discussing the theory and practice of biological remediation of petroleum hydrocarbon contaminated soils and assessing the effects of operational conditions and parameters such as: temperature, dissolved oxygen concentration and  pH on the removal rate of the target contaminant which is handled in the designed reactor. Due to large production and consumption rate of diesel fuel inIran and many other countries, diesel fuel has been selected as target contaminant. In this study TOC and COD testing methods have been used to measure and assess the removal rate of the contaminant in the reactor. The experimental results indicate that, considering the operational conditions the indigenous microorganisms which have been separated from the soil are able to remove 50 to 83 percent of the contaminant after 30 days. Thereafter on the base of the results and considering the laboratorial specifications and conditions applied in this project, the optimum values of temperature, dissolved oxygen concentration andpH were respectively determined as 35°C, 4mg/L and 7.

  7. Norway spruce fine root dynamics and carbon input into soil in relation to environmental factors

    OpenAIRE

    Leppälammi-Kujansuu, Jaana

    2014-01-01

    Knowledge of the quantity of belowground litter carbon (C) input is scarce but highly valued in C budget calculations. Specifically, the turnover rate of fine roots is considered to be one of the most important parameters in the estimation of changes in soil C stock. In this thesis Norway spruce (Picea abies L. (Karst.)) fine root lifespan and litter production and their responses to nutrient availability and temperature were examined. Aboveground foliage and understory litter C inputs were a...

  8. Factors inhibiting bioremediation of soil contaminated with weathered oils and drill cuttings

    International Nuclear Information System (INIS)

    Chaillan, F.; Chaineau, C.H.; Point, V.; Saliot, A.; Oudot, J.

    2006-01-01

    Oily drill cuttings and a soil contaminated with weathered crude oils were treated by enhanced biodegradation under tropical conditions in industrial scaled experiments. Oil contaminants were characterized by gas chromatography and mass spectrometry. This allowed for the identification of a mixture of two crude oils in the contaminated soil. After 12 months of bioremediation process, the removal of hydrocarbons reached by biodegradation an extent of 60% although nutrient amendment with elevated concentration of N-urea had highly detrimental effects on the hydrocarbon degrading fungal populations due to the production of toxic concentration of ammonia gas by nitrification. The saturated hydrocarbons were extensively assimilated, though n-alkanes were not completely removed. Aromatic hydrocarbons were less degraded than saturated whereas resin and asphaltene fractions were, surprisingly, partly assimilated. In laboratory conditions, the residual hydrocarbons in the field-treated materials were 15-20% further degraded when metabolic byproducts resulting from biodegradation were diluted or removed. - Bioremediation of oil-polluted soils can be impaired if urea is used as nitrogen source, and metabolic byproducts can limit biodegradation rates in industrial scaled experiments

  9. Organic-Carbon Sequestration in Soil/Sediment of the Mississippi River Deltaic Plain - Data; Landscape Distribution, Storage, and Inventory; Accumulation Rates; and Recent Loss, Including a Post-Katrina Preliminary Analysis (Chapter B)

    Science.gov (United States)

    Markewich, Helaine W.; Buell, Gary R.; Britsch, Louis D.; McGeehin, John P.; Robbins, John A.; Wrenn, John H.; Dillon, Douglas L.; Fries, Terry L.; Morehead, Nancy R.

    2007-01-01

    Soil/sediment of the Mississippi River deltaic plain (MRDP) in southeastern Louisiana is rich in organic carbon (OC). The MRDP contains about 2 percent of all OC in the surface meter of soil/sediment in the Mississippi River Basin (MRB). Environments within the MRDP differ in soil/sediment organic carbon (SOC) accumulation rate, storage, and inventory. The focus of this study was twofold: (1) develop a database for OC and bulk density for MRDP soil/sediment; and (2) estimate SOC storage, inventory, and accumulation rates for the dominant environments (brackish, intermediate, and fresh marsh; natural levee; distributary; backswamp; and swamp) in the MRDP. Comparative studies were conducted to determine which field and laboratory methods result in the most accurate and reproducible bulk-density values for each marsh environment. Sampling methods included push-core, vibracore, peat borer, and Hargis1 sampler. Bulk-density data for cores taken by the 'short push-core method' proved to be more internally consistent than data for samples collected by other methods. Laboratory methods to estimate OC concentration and inorganic-constituent concentration included mass spectrometry, coulometry, and loss-on-ignition. For the sampled MRDP environments, these methods were comparable. SOC storage was calculated for each core with adequate OC and bulk-density data. SOC inventory was calculated using core-specific data from this study and available published and unpublished pedon data linked to SSURGO2 map units. Sample age was estimated using isotopic cesium (137Cs), lead (210Pb), and carbon (14C), elemental Pb, palynomorphs, other stratigraphic markers, and written history. SOC accumulation rates were estimated for each core with adequate age data. Cesium-137 profiles for marsh soil/sediment are the least ambiguous. Levee and distributary 137Cs profiles show the effects of intermittent allochthonous input and/or sediment resuspension. Cesium-137 and 210Pb data gave the most

  10. A comparison between soil loss evaluation index and the C-factor of RUSLE: a case study in the Loess Plateau of China

    Directory of Open Access Journals (Sweden)

    W. W. Zhao

    2012-08-01

    Full Text Available Land use and land cover are most important in quantifying soil erosion. Based on the C-factor of the popular soil erosion model, Revised Universal Soil Loss Equation (RUSLE and a scale-pattern-process theory in landscape ecology, we proposed a multi-scale soil loss evaluation index (SL to evaluate the effects of land use patterns on soil erosion. We examined the advantages and shortcomings of SL for small watershed (SLsw by comparing to the C-factor used in RUSLE. We used the Yanhe watershed located on China's Loess Plateau as a case study to demonstrate the utilities of SLsw. The SLsw calculation involves the delineations of the drainage network and sub-watershed boundaries, the calculations of soil loss horizontal distance index, the soil loss vertical distance index, slope steepness, rainfall-runoff erosivity, soil erodibility, and cover and management practice. We used several extensions within the geographic information system (GIS, and AVSWAT2000 hydrological model to derive all the required GIS layers. We compared the SLsw with the C-factor to identify spatial patterns to understand the causes for the differences. The SLsw values for the Yanhe watershed are in the range of 0.15 to 0.45, and there are 593 sub-watersheds with SLsw values that are lower than the C-factor values (LOW and 227 sub-watersheds with SLsw values higher than the C-factor values (HIGH. The HIGH area have greater rainfall-runoff erosivity than LOW area for all land use types. The cultivated land is located on the steeper slope or is closer to the drainage network in the horizontal direction in HIGH area in comparison to LOW area. The results imply that SLsw can be used to identify the effect of land use distribution on soil loss, whereas the C-factor has less power to do it. Both HIGH and LOW areas have similar soil erodibility values for all land use types. The average vertical

  11. Schistosoma mansoni and soil-transmitted helminths among preschool-aged children in Chuahit, Dembia district, Northwest Ethiopia: prevalence, intensity of infection and associated risk factors.

    Science.gov (United States)

    Alemu, Agersew; Tegegne, Yalewayker; Damte, Demekech; Melku, Mulugeta

    2016-05-23

    Intestinal schistosomiasis and soil-transmitted helminthiasis are the major public health problems globally. Compared with any other age group, pre-school aged children and school-aged children are the most exposed. There are few studies showing the burden of intestinal schistosomiasis, and soil-transmitted helminthiasis among pre-school aged children in Ethiopia. Hence, this study aimed to assess the prevalence of schistosoma mansoni and soil-transmitted helminths and associated risk factors among preschool aged children of Chuahit and surrounding Kebeles, Northwest Ethiopia. A community based cross sectional study was conducted from February 2 to March 27 2015. Four hundred one preschool-aged children were included in the study by using two stage cluster sampling technique. Pretested structured questionnaire was employed to collected data via face-to-face interview technique. A single stool specimen was collected, and a portion of the sample was processed by Kato Katz method. Of the total children, 141 (35.2 %) harbored one or more intestinal helminthes. Schistosoma mansoni was found in 45 (11.2 %) of preschool age children. Ascaris lumbricoides was the predominant isolate, 77 (19.2 %) followed by S. mansoni, 45 (11.2 %). The least parasites isolated were Tania species, 2 (0.5 %). After adjusting for other variables, being mothers who did not have the habit of washing hands after toilet (AOR = 7.3, 95%CI: 2.97-17.95), being occupationally housewife mothers (AOR = 8.9, 95%CI: 2.27-25.4), using protected spring water as a main family source of water (AOR = 3.9, 95%CI: 1.2-12.3) and child habit of not wearing shoe (AOR = 1.91, 95%CI: 1.01-3.64) were significantly associated with high prevalence of soil-transmitted helminthiasis among preschool-age children in Chuahit. The current study showed that relatively higher level of STH and S. mansoni among preschool-aged children in Chuahit. This finding calls for a need of public health education

  12. Schistosoma mansoni and soil-transmitted helminths among preschool-aged children in Chuahit, Dembia district, Northwest Ethiopia: prevalence, intensity of infection and associated risk factors

    Directory of Open Access Journals (Sweden)

    Agersew Alemu

    2016-05-01

    Full Text Available Abstract Background Intestinal schistosomiasis and soil-transmitted helminthiasis are the major public health problems globally. Compared with any other age group, pre-school aged children and school-aged children are the most exposed. There are few studies showing the burden of intestinal schistosomiasis, and soil-transmitted helminthiasis among pre-school aged children in Ethiopia. Hence, this study aimed to assess the prevalence of schistosoma mansoni and soil-transmitted helminths and associated risk factors among preschool aged children of Chuahit and surrounding Kebeles, Northwest Ethiopia. Methods A community based cross sectional study was conducted from February 2 to March 27 2015. Four hundred one preschool-aged children were included in the study by using two stage cluster sampling technique. Pretested structured questionnaire was employed to collected data via face-to-face interview technique. A single stool specimen was collected, and a portion of the sample was processed by Kato Katz method. Results Of the total children, 141 (35.2 % harbored one or more intestinal helminthes. Schistosoma mansoni was found in 45 (11.2 % of preschool age children. Ascaris lumbricoides was the predominant isolate, 77 (19.2 % followed by S. mansoni, 45 (11.2 %. The least parasites isolated were Tania species, 2 (0.5 %. After adjusting for other variables, being mothers who did not have the habit of washing hands after toilet (AOR = 7.3, 95%CI: 2.97–17.95, being occupationally housewife mothers (AOR = 8.9, 95%CI: 2.27–25.4, using protected spring water as a main family source of water (AOR = 3.9, 95%CI: 1.2–12.3 and child habit of not wearing shoe (AOR = 1.91, 95%CI: 1.01–3.64 were significantly associated with high prevalence of soil-transmitted helminthiasis among preschool-age children in Chuahit. Conclusion The current study showed that relatively higher level of STH and S. mansoni among preschool-aged children in

  13. Termites as a factor of spatial differentiation of CO2 fluxes from the soils of monsoon tropical forests in Southern Vietnam

    Science.gov (United States)

    Lopes de Gerenyu, Valentin; Anichkin, Alexander

    2016-04-01

    Termites play the key role in biogeochemical transformation of organic matter acting as "moderators" of fluxes of carbon and other nutrients. They destroy not only leave litter but also coarse woody debris. Termites translocate considerable masses of dead organic materials into their houses, which leads to significant accumulations of organic matter in termite mounds. We studied the impact of termite mounds on redistribution of CO2 fluxes from soils in semi-deciduous monsoon tropical forests of southern Vietnam. Field study was performed in the Cat Tien National Park (11°21'-11°48'N, 107°10'-107°34'E). The spatial and temporary dynamics of CO2 fluxes from soils (Andosols) populated by termites were studied in plain lagerstroemia (Lagerstroemia calyculata Kurz) monsoon tropical forests. The rate of CO2 emission from the soil surface was measured by closed chamber method two-three times per month from November 2010 to December 2011. Permanent cylindrical PVC chambers (9 cm in diameter and 15 cm in height) were installed beyond the areas occupied by termite mounds (5 replications). Litter was not removed from the soil surface before the measurements. To estimate the spatial heterogeneity of the CO2 emission fluxes from soils populated by termites, a special 'termite' plot (TerPl) was equipped. It was 10×10 m in size and included three termite mounds: one mound built up by Globitermes sulphureus and two mounds populated by termites of the Odontotermes genus. Overall, 52 PVC chambers were installed permanently on the 'termite' plot (ca. 1 m apart from one another). The CO2 emission rate from TerPl was also measured by chamber closed method once in the dry season (April) and twice through the wet season (July and August). The average rate of CO2 emission from termite mounds was two times higher than that from the surrounding area (SurAr). In the dry season, it comprised 91±7 mg C/m2/h from the surrounding soils and 196±16 mg C/m2/h from the termite mounds. In the

  14. Analyses of the influencing factors of soil microbial functional gene diversity in tropical rainforest based on GeoChip 5.0

    Directory of Open Access Journals (Sweden)

    Jing Cong

    2015-09-01

    Full Text Available To examine soil microbial functional gene diversity and causative factors in tropical rainforests, we used a microarray-based metagenomic tool named GeoChip 5.0 to profile it. We found that high microbial functional gene diversity and different soil microbial metabolic potential for biogeochemical processes were considered to exist in tropical rainforest. Soil available nitrogen was the most associated with soil microbial functional gene structure. Here, we mainly describe the experiment design, the data processing, and soil biogeochemical analyses attached to the study in details, which could be published on BMC microbiology Journal in 2015, whose raw data have been deposited in NCBI's Gene Expression Omnibus (accession number GSE69171.

  15. Evaluation and development of soil values for the pathway 'soil to plant'. Transfer factors soil to plant; Ueberpruefung und Fortentwicklung der Bodenwerte fuer den Boden-Pflanze-Pfad. Teilbericht 1: Transferfaktoren Boden-Pflanze

    Energy Technology Data Exchange (ETDEWEB)

    Trapp, S.; Matthies, M.; Reiter, B.; Gaeth, S.

    2001-10-01

    Within the research project 'Ueberpruefung und Fortentwicklung der Bodenwerte fuer den Boden-Pflanzen-Pfad', transfer factors soil to plant were calculated for compounds of the substance classes PCB and PAH. Literature studies, experiments undertaken by the LUA/Essen at the lysimeter research station Waldfeucht, and model simulations were used. The transfer differs for the plant species. For kale and wheat straw, the dominant uptake is from air. For lettuce and spinach, a significant uptake from soil was found. The main transport seems to occur via soil resuspension and volatilization, followed by sorption to leaf surfaces. These processes act mainly on low growing harvest products. Uptake from the soil solution and translocation within the plant do not seem to play a role except for phenanthren. The carrots and potatoes investigated showed only a contamination of the peel. The transfer factors of the PCB were throughout higher than that of the PAH. We assume that photolytic processes of PAH on plant surfaces are responsible. Furthermore, there are hints in literature that the metabolism of PAH in plants is faster than that of the PCB. (orig.) [German] Im Rahmen des Forschungsvorhabens 'Ueberpruefung und Fortentwicklung der Bodenwerte fuer den Boden-Pflanze-Pfad' wurden fuer organische Schadstoffe aus den Stoffklassen PCB und PAK Transferfaktoren Boden-Pflanze errechnet. Hierzu wurden Literaturstudien, Experimente der LUA von der Lysimeteranlage Waldfeucht sowie Modellsimulationen eingesetzt. Der Transfer ist fuer die untersuchten Pflanzen nicht einheitlich. Fuer Gruenkohl und Weizenstroh wurde eine Dominanz