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Sample records for sobre suelos cambisoles

  1. Microbial responses to southward and northward Cambisol soil transplant

    SciTech Connect

    Wang, Mengmeng; Liu, Shanshan; Wang, Feng; Sun, Bo; Zhou, Jizhong; Yang, Yunfeng

    2015-10-26

    We report that soil transplant serves as a proxy to simulate climate changes. Recently, we have shown that southward transplant of black soil and northward transplant of red soil altered soil microbial communities and biogeochemical variables. However, fundamental differences in soil types have prevented direct comparison between southward and northward transplants. To tackle it, herein we report an analysis of microbial communities of Cambisol soil in an agriculture field after 4 years of adaptation to southward and northward soil transplants over large transects. Analysis of bare fallow soils revealed concurrent increase in microbial functional diversity and coarse-scale taxonomic diversity at both transplanted sites, as detected by GeoChip 3.0 and DGGE, respectively. Furthermore, a correlation between microbial functional diversity and taxonomic diversity was detected, which was masked in maize cropped soils. Mean annual temperature, soil moisture, and nitrate (NO3¯-N) showed strong correlations with microbial communities. In addition, abundances of ammonium-oxidizing genes (amoA) and denitrification genes were correlated with nitrification capacity and NO3¯-N contents, suggesting that microbial responses to soil transplant could alter microbe-mediated biogeochemical cycle at the ecosystem level.

  2. Microbial responses to southward and northward Cambisol soil transplant

    DOE PAGESBeta

    Wang, Mengmeng; Liu, Shanshan; Wang, Feng; Sun, Bo; Zhou, Jizhong; Yang, Yunfeng

    2015-10-26

    We report that soil transplant serves as a proxy to simulate climate changes. Recently, we have shown that southward transplant of black soil and northward transplant of red soil altered soil microbial communities and biogeochemical variables. However, fundamental differences in soil types have prevented direct comparison between southward and northward transplants. To tackle it, herein we report an analysis of microbial communities of Cambisol soil in an agriculture field after 4 years of adaptation to southward and northward soil transplants over large transects. Analysis of bare fallow soils revealed concurrent increase in microbial functional diversity and coarse-scale taxonomic diversity atmore » both transplanted sites, as detected by GeoChip 3.0 and DGGE, respectively. Furthermore, a correlation between microbial functional diversity and taxonomic diversity was detected, which was masked in maize cropped soils. Mean annual temperature, soil moisture, and nitrate (NO3¯-N) showed strong correlations with microbial communities. In addition, abundances of ammonium-oxidizing genes (amoA) and denitrification genes were correlated with nitrification capacity and NO3¯-N contents, suggesting that microbial responses to soil transplant could alter microbe-mediated biogeochemical cycle at the ecosystem level.« less

  3. Determinacion de periodos fundamentales del suelo mediante vibraciones ambientales en el municipio de Humacao, Puerto Rico

    NASA Astrophysics Data System (ADS)

    Cintron Aponte, Rommel

    La tecnica de Nakamura ha sido utilizada a nivel mundial para determinar periodos fundamentales del suelo. La tecnica consiste en calcular y graficar cocientes espectrales H/V de vibraciones ambientales registradas sobre el suelo. Mediciones de vibraciones ambientales fueron tomadas en 151 lugares dentro del municipio de Humacao, localizado al este de Puerto Rico. Los datos se procesaron utilizando espectros de Fourier y espectros de potencia. La tecnica fue validada al compararla con los resultados de cocientes espectrales H/V de registros de sismos debiles y tambien con una modelacion numerica realizada con datos de un ensayo "downhole". Las graficas de los cocientes espectrales H/V fueron divididas en casos y grupos, los cuales dependen de la facilidad para identificar el periodo fundamental pico y amplitudes en frecuencias menores de 1 Hz, respectivamente. Los resultados obtenidos con ambos espectros fueron comparados y se concluye que los mismos se complementan para proveer resultados mas confiables. Se crearon mapas de periodos fundamentales, factores de amplitud, isoperiodos y clasificacion sismica de sitio. Los mapas de isoperiodos fueron realizados en las zonas mas pobladas sobre depositos de suelo. El mapa de periodos fundamentales del suelo mostro buena correlacion con la geologia local. El mapa de clasificacion sismica derivado de periodos de sitio fue comparado con el mapa de clasificacion sismica derivado de barrenos geotecnicos. El mapa de clasificacion obtenido de periodos puede sobreestimar un poco algunas clasificaciones del suelo. Sin embargo, este mapa puede proveer un estimado aproximado de la velocidad de onda de corte promedio del suelo hasta una profundidad de 100 pies (30 metros).

  4. Contrasting agronomic response of biochar amendment to a Mediterranean Cambisol: Incubation vs. field experiment

    NASA Astrophysics Data System (ADS)

    De la Rosa, José M.; Paneque, Marina; De Celis, Reyes; Miller, Ana Z.; Knicker, Heike

    2015-04-01

    wood biochars. The FESEM-EDS distinguished compositional and structural differences of the studied biochars such as macropores on the surface of pyrolysis wood biochars. In the frame of a pot experiment, the biochar characteristics (physical properties and chemical composition) were related to the germination rates and to the plant biomass production of a Lolium perenne. Incubation was carried out in 300 mL pots during 79 days in which a calcic Cambisol [3] was amended with 10, 20 and 40 t ha-1 biochar. After adjusting the soil humidity to 60% of the maximum water holding capacity (WHC), the pots were placed into a greenhouse under similar conditions than those reported by [4]. Biochar amendment improved significantly germination rates and soil fertility (excepting kiln wood biochar), and had no negative pH impact on the already alkaline soil. Application of sewage sludge biochar, the richest in minerals and nitrogen, resulted in the highest soil fertility. In this case, increase of the dose went along with an enhancement of plant production. Considering further costs due to production and transport of biochar, the application of 10 t ha-1 turned out as the most efficient for the crop and soil used in the incubation experiment [further details in 5]. The field study was performed with seeds of Helianthus annuus, at the experimental station "La Hampa", located in the Guadalquivir river valley (SW Spain; 37° 21.32' N, 6° 4.07' W), Seville. The calcic Cambisol which was also used as matrix for the pot experiments was amended with doses equivalent to 0 (control), 1.5 and 15 t ha-1 of the five biochars, making a total of 12 different treatments. Soil properties and composition were monitored during the growing time including elemental composition, pH, water holding capacity and soil microbial biomass. After 6 months of growth, sunflower plants were harvested. Plant height, chlorophyll content and sunflower seeds production were recorded. Results of this field experiment

  5. Contrasting agronomic response of biochar amendment to a Mediterranean Cambisol: Incubation vs. field experiment

    NASA Astrophysics Data System (ADS)

    De la Rosa, José M.; Paneque, Marina; De Celis, Reyes; Miller, Ana Z.; Knicker, Heike

    2015-04-01

    wood biochars. The FESEM-EDS distinguished compositional and structural differences of the studied biochars such as macropores on the surface of pyrolysis wood biochars. In the frame of a pot experiment, the biochar characteristics (physical properties and chemical composition) were related to the germination rates and to the plant biomass production of a Lolium perenne. Incubation was carried out in 300 mL pots during 79 days in which a calcic Cambisol [3] was amended with 10, 20 and 40 t ha-1 biochar. After adjusting the soil humidity to 60% of the maximum water holding capacity (WHC), the pots were placed into a greenhouse under similar conditions than those reported by [4]. Biochar amendment improved significantly germination rates and soil fertility (excepting kiln wood biochar), and had no negative pH impact on the already alkaline soil. Application of sewage sludge biochar, the richest in minerals and nitrogen, resulted in the highest soil fertility. In this case, increase of the dose went along with an enhancement of plant production. Considering further costs due to production and transport of biochar, the application of 10 t ha-1 turned out as the most efficient for the crop and soil used in the incubation experiment [further details in 5]. The field study was performed with seeds of Helianthus annuus, at the experimental station "La Hampa", located in the Guadalquivir river valley (SW Spain; 37° 21.32' N, 6° 4.07' W), Seville. The calcic Cambisol which was also used as matrix for the pot experiments was amended with doses equivalent to 0 (control), 1.5 and 15 t ha-1 of the five biochars, making a total of 12 different treatments. Soil properties and composition were monitored during the growing time including elemental composition, pH, water holding capacity and soil microbial biomass. After 6 months of growth, sunflower plants were harvested. Plant height, chlorophyll content and sunflower seeds production were recorded. Results of this field experiment

  6. Biochemical stability of sewage sludge chars and their impact on soil organic matter of a Mediterranean Cambisol

    NASA Astrophysics Data System (ADS)

    Paneque, Marina; María De la Rosa, José; Aragón, Carlos; Kern, Jürgen; Knicker, Heike

    2016-04-01

    Transformation of sewage sludge (SS) into char achieves sludge hygienisation, which is necessary prior its application into agricultural soils. The pyrolysis of SS increases its stability in a degree which depends on the thermal treatment used. Thus, chars produced by using hydrothermal carbonization are typically more stable than normal soil organic matter (SOM), but less stable than chars from dry pyrolysis (Libra et al., 2011). Addition of highly-recalcitrant SS-chars to soil will likely increase its carbon sequestration potential; however the fertilizing properties of SS may be compromised due to its alteration during the pyrolysis. The main goal of this work was to investigate the biochemical recalcitrance of two 13C-enriched SS-chars once applied in a Mediterranean Cambisol as well as to evaluate their impact on the SOM quality and carbon stability. Thus, we studied the distribution of 13C between plants and soil after the addition of the 13C-enriched chars (2 atm%) to the soil. Therefore, we performed a greenhouse incubation experiment, using a Mediterranean Cambisol as matrix and tested the following treatments: control (soil alone), raw SS, SS-hydrochar, SS-pyrochar. The SS was produced in a pilot-scale waste-water plant and enriched with 13C by the addition of 13C-glucose during the treatment. The amendment was only applied to the upper 2 cm of the soil matrix where it accounted for 5% of its dry weight. Per pot, 25 seeds of Lolium perenne were sowed and incubated under controlled conditions. The biomass production as well as the concentration of 13C in leaves and roots was determined after 1, 2 and 5 months. The partitioning of the 13C between soil and plant and its transformation into bioavailable forms were monitored by stable isotopic mass spectrometry. The 13C-enrichment of the chars allowed the use of solid-state 13C NMR spectroscopy as a means for the detection of chemical alterations of the chars during their aging. Libra J., Ro K., Kammann C

  7. Characterization of soil phosphorus in a fire-affected forest Cambisol by chemical extractions and (31)P-NMR spectroscopy analysis.

    PubMed

    Turrion, María-Belén; Lafuente, Francisco; Aroca, María-José; López, Olga; Mulas, Rafael; Ruipérez, Cesar

    2010-07-15

    This study was conducted to investigate the long-term effects of fire on soil phosphorus (P) and to determine the efficiency of different procedures in extracting soil P forms. Different P forms were determined: labile forms (Olsen-P, Bray-P, and P extracted by anion exchange membranes: AEM-P); moderately labile inorganic and organic P, obtained by NaOH-EDTA extraction after removing the AEM-P fraction; and total organic and inorganic soil P. (31)P-NMR spectroscopy was used to characterize the structure of alkali-soluble P forms (orthophosphate, monoester, pyrophosphate, and DNA). The studied area was a Pinus pinaster forest located at Arenas de San Pedro (southern Avila, Spain). The soils were Dystric Cambisols over granites. Soil samples were collected at 0-2 cm, 2-5 cm, and 10-15 cm depths, two years after a fire in the burned area and in an adjacent unburned forest area. Fire increased the total N, organic C, total P, and organic and inorganic P content in the surface soil layer. In burned soil, the P extracted by the sequential procedure (AEM and NaOH+EDTA) was about 95% of the total P. Bray extraction revealed a fire-induced increase in the sorption surfaces. Analysis by chemical methods overestimated the organic P fraction in the EDTA-NaOH extract in comparison with the determination by ignition procedure. This overestimation was more important in the burned than unburned soil samples, probably due to humification promoted by burning, which increased P sorption by soil particles. The fire-induced changes on the structure of alkali-soluble P were an increase in orthophosphate-P and a decrease in monoester-P and DNA-P. PMID:20452650

  8. Relating physical and chemical properties of four different biochars and their application rate to biomass production of Lolium perenne on a Calcic Cambisol during a pot experiment of 79 days.

    PubMed

    de la Rosa, José M; Paneque, Marina; Miller, Ana Z; Knicker, Heike

    2014-11-15

    Three pyrolysis biochars (B1: wood, B2: paper-sludge, B3: sewage-sludge) and one kiln-biochar (B4: grapevine wood) were characterized by determining different chemical and physical properties which were related to the germination rates and to the plant biomass production during a pot experiment of 79 days in which a Calcic Cambisol from SW Spain was amended with 10, 20 and 40 t ha(-1) of the four biochars. Biochar 1, B2 and B4 revealed comparable elemental composition, pH, water holding capacity and ash content. The H/C and O/C atomic ratios suggested high aromaticity of all biochars, which was confirmed by (13)C solid-state NMR spectroscopy. The FT-IR spectra confirmed the aromaticity of all the biochars as well as several specific differences in their composition. The FESEM-EDS distinguished compositional and structural differences of the studied biochars such as macropores on the surface of B1, collapsed structures in B2, high amount of mineral deposits (rich in Al, Si, Ca and Fe) and organic phases in B3 and vessel structures for B4. Biochar amendment improved germination rates and soil fertility (excepting for B4), and had no negative pH impact on the already alkaline soil. Application of B3, the richest in minerals and nitrogen, resulted in the highest soil fertility. In this case, increase of the dose went along with an enhancement of plant production. Considering costs due to production and transport of biochar, for all used chars with the exception of B3, the application of 10 t ha(-1) turned out as the most efficient for the crop and soil used in the present incubation experiment. PMID:25181049

  9. Conversation with Lara about the Earth and Land. (Spanish Title: Conversando con Lara sobre la Tierra y la Teirra.) Conversando com Lara sobre a Terra e a Terra

    NASA Astrophysics Data System (ADS)

    da Conceição Barbosa-Lima, Maria

    2010-12-01

    The present article is the analysis of a conversation between the author and Lara, a four-yearold- girl, enrolled in nursery school, while she makes a drawing of the Earth. It took place outside school environment and without any other person around to avoid interference during the interview. According to Ferreira & Silva (2004), a researcher can only comprehend a child's drawing, or form, by listening to him/her while he/she is creating it. Lara presented the traditional flat drawing, picturing the sky parallel to the ground, as reported by Nardi & Carvalho (1996). However, when asked to draw the World - term used by Butterworth et al. (2002), in order to avoid unnecessary confusion - she represented it by a circle, with herself on the surface. Her drawings led to the conclusion that such girl does not know yet the World in which she lives is the Earth, and probably because of that, within her age and consequent maturity, she accurately differentiates the concepts of land and Earth. El presente artículo analiza una entrevista libre, mientras una niña de 4 años y 4 meses, matriculada en el pregrado, dibuja la Tierra. Esta entrevista se realizó fuera del ambiente escolar y sin otra persona alrededor que pudiera interferir. De acuerdo con Ferreira Silva (2004), para quien investiga es posible conocer realmente lo que un niño o una niña pone en el papel a través de grafismos y/o dibujos si se lo escucha durante el proceso de creación de la escritura con imágenes. La niña, en este caso, representa la Tierra con el tradicional dibujo plano y el "cielo" paralelo al suelo, conforme analizaron Nardi & Carvalho (1996). Pero, cuando se Le solicita dibujar el "Mundo" - palabra empleada en un trabajo de Butterworth et al. (2002), con intención de no provocar "confusiones" innecesarias a sus sujetos de investigación- lo representa de forma circular, poniéndose sobre su superficie. Sus dibujos llevan a concluir que esta niña aún no tiene conocimiento que el mundo

  10. Simulating transport of nitrogen and phosphorus in a Cambisol after natural and simulated intense rainfall.

    PubMed

    Kaufmann, Vander; Pinheiro, Adilson; Castro, Nilza Maria dos Reis

    2014-05-01

    Intense rainfall adversely affects agricultural areas, causing transport of pollutants. Physically-based hydrological models to simulate flows of water and chemical substances can be used to help decision-makers adopt measures which reduce such problems. The purpose of this paper is to evaluate the performance of SWAP and ANIMO models for simulating transport of water, nitrate and phosphorus nutrients, during intense rainfall events generated by a simulator, and during natural rainfall, on a volumetric drainage lysimeter. The models were calibrated and verified using daily time series and simulated rainfall measured at 10-minute intervals. For daily time-intervals, the Nash-Sutcliffe coefficient was 0.865 for the calibration period and 0.805 for verification. Under simulated rainfall, these coefficients were greater than 0.56. The pattern of both nitrate and phosphate concentrations in daily drainage flow under simulated rainfall was acceptably reproduced by the ANIMO model. In the simulated rainfall, loads of nitrate transported in surface runoff varied between 0.08 and 8.46 kg ha(-1), and in drainage form the lysimeter, between 2.44 and 112.57 kg ha(-1). In the case of phosphate, the loads transported in surface runoff varied between 0.002 and 0.504 kg ha(-1), and in drainage, between 0.005 and 1.107 kg ha(-1). The use of the two models SWAP and ANIMO shows the magnitudes of nitrogen and phosphorus fluxes transported by natural and simulated intense rainfall in an agricultural area with different soil management procedures, as required by decision makers. PMID:24650647

  11. Estudio muestra importancia de conversaciones tempranas sobre el cuidado en etapa final de la vida

    Cancer.gov

    Artículo sobre la importancia de hablar en forma temprana sobre el cuidado paliativo para asegurar que la atención prestada en la etapa final de la vida sea más acorde con las preferencias de los pacientes.

  12. Nitrification and acidification from urea application in red soil (Ferralic Cambisol) after different long-term fertilization treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purpose. Long-term manure applications can prevent or reverse soil acidification by chemical nitrogen (N) fertilizer. However, the resistance to re-acidification from further chemical fertilization is unknown. The aim of this study was to examine the effect of urea application on nitrification and a...

  13. Informe Anual a la Nación sobre el Estado del Cáncer con una sección especial sobre la prevalencia d

    Cancer.gov

    El Informe Anual a la Nación sobre el Estado del Cáncer (1975 a 2010), mostró un descenso más acelerado que en años anteriores de los índices de mortalidad por cáncer de pulmón. También contiene una sección especial que destaca los efectos significativos

  14. Some Research-Based Issues and Recommendations Expressed at the Seminario Internacional Sobre la Educacion Bilingue.

    ERIC Educational Resources Information Center

    Bernal, Ernesto M.

    The first Seminario Internacional Sobre la Educacion Bilingue (International Seminar on Bilingual Education), under the aegis of the National Association for Bilingual Education and the Mexican secretary for public education, brought together professionals from Canada, the United States, and Mexico in Oaxtepec, Mexico in November 1986 to share…

  15. Informe del NCI y los CDC sobre el tabaco sin humo

    Cancer.gov

    El primer informe sobre el consumo mundial del tabaco sin humo y sus consecuencias en la salud pública reveló que más de 300 millones de personas en al menos 70 países usan estos productos dañinos.

  16. Gestion responsable del carbono en el suelo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The world's agronomists must broaden their perspective and shift conservation concepts and programs to get away from managing for only yield and erosion control and move to managing soil carbon (C) for crop production sustainability and maintaining environmental quality. This work reviews research o...

  17. Discussions about the Nature of Science in a Course on the History of Astronomy. (Spanish Title: Discusiones sobre la Naturaleza de la Ciencia en un Curso sobre Historia de la Astronomía.) Discussões sobre a Natureza da Ciência em um Curso sobre a História da Astronomia

    NASA Astrophysics Data System (ADS)

    Pires de Andrade, Victória Flório; L'Astorina, Bruno

    2010-07-01

    There are an increasing number of researches in science education that affirm the importance of discussions on the "nature of science" in basic education level as well as in teacher training. The history of science applied to education is a way to contextualize epistemological discussions, allowing both the understanding of scientific content and learning about science concepts. We present some reasonably consensual definitions on the nature of science that have been widely discussed by the academic community. We show also some episodes in the history of astronomy which can lead to discussions involving some aspects of the nature of science, and how they can do it. Hay un número creciente de investigaciones en la enseñanza de las ciencias que afirman la importancia de debates sobre la "naturaleza de la ciencia" en la educación básica y formación del profesorado. La historia de la ciencia aplicada a la educación es una manera de contextualizar los debates de la epistemología, lo que permite tanto la comprensión de los contenidos científicos como el aprendizaje de conceptos científicos. En esto trabajo, presentamos algunas definiciones bastante consensuales sobre la naturaleza de la ciencia que han sido ampliamente discutidas por la comunidad académica y mostramos cómo algunos episodios en la historia de la astronomía pueden llevar a discusiones sobre algunos aspectos de la naturaleza de la ciencia. Há um número crescente de pesquisas na área de ensino de ciências que afirmam a importância de discussões sobre a "natureza da ciência" na educação básica e na formação de professores. A história da ciência aplicada ao ensino é uma maneira de contextualizar discussões epistemológicas, permitindo tanto a compreensão de conteúdos científicos quanto o aprendizado de noções sobre as ciências. Neste trabalho apresentamos algumas definições razoavelmente consensuais sobre a natureza da ciência que foram amplamente discutidas pela

  18. Acidification rate from chemical N fertilization and alleviation by manure in an 18–year field experiment in a ferralic cambisol, South China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil acidification from chemical N fertilization has worsened and is a major yield-limiting factor in the red soils of southern China. Assessment of the acidification process under field conditions over a long term is essential to develop strategies for maintaining soil productivity. The objective o...

  19. Informe Anual a la Nación sobre el Estado del Cáncer, 1975 a 2012

    Cancer.gov

    El Informe Anual a la Nación sobre el Estado del Cáncer, 1975 a 2012, es una actualización de los índices de casos nuevos, muertes y tendencias de los cánceres más comunes en los Estados Unidos.

  20. El Informe a la Nación sobre el Estado del Cáncer, 1975-2012

    Cancer.gov

    El Informe a la Nación sobre el Estado del Cáncer (1975-2012) indica que continuó la baja de tasas de mortalidad de todos los cánceres juntos, así como de la mayoría de los cánceres en hombres y mujeres de todos los grupos raciales y étnicos principales.

  1. O que bilíngues bimodais têm a nos dizer sobre desenvolvimento bilíngue?

    PubMed Central

    de Quadros, Ronice Müller; Lillo-Martin, Diane; Pichler, Deborah Chen

    2013-01-01

    O objetivo deste trabalho é apresentar o que as pesquisas que estamos desenvolvendo com crianças ouvintes, filhas de pais surdos, adquirindo Língua Brasileira de Sinais (Libras) e Português e Língua de Sinais Americana (ASL) e Inglês (Lillo-Martin et al. 2010) têm a nos dizer sobre desenvolvimento bilíngue. Os dados deste estudo fazem parte de um banco de dados de interações espontâneas coletadas longitudinalmente, alternando contextos de aquisição da Libras e do português como língua alvo, no Brasil e dados coletados longitudinalmente. nos mesmos contextos, de crianças adquirindo ASL e inglês1. Além disso, há também dados do estudo experimental com testes aplicados nos dois pares de línguas que se agregam ao presente estudo. Uma visão geral dos estudos desenvolvidos sobre a aquisição bilíngue bimodal por crianças ouvintes, filhas de pais surdos, será apresentada e, então, serão expostos alguns aspectos linguísticos deste tipo de aquisição, considerando as discussões sobre aquisição bilíngue a partir da pesquisa realizada. PMID:24431480

  2. University Students' Conceptions about the Moon Phases. (Spanish Title: Concepciones de Estudiantes Universitários sobre Las Fases de la Luna.) Concepções de Estudantes Universitários sobre as Fases da Lua

    NASA Astrophysics Data System (ADS)

    de Fátima Oliveira Saraiva, Maria; da Silveira, Fernando Lang; Steffani, Maria Helena

    2011-07-01

    In this article we describe the development of a multiple choice test about lunar phases and analyze the results of its application to ten groups of Physics students at the UFRGS. During the improvement of the test, we noticed that the percentage of right answers about some concepts increased significantly when associated with the reformulation of the question, emphasizing the importance of being careful to avoid incorrect answers generated by unclear questions, and not by ignorance on the matter. We confirm the results of other studies that show that students have great difficulty to relate the Moon's phase with its position in the sky at given time. On the other hand, our results suggest that, in general, students of Physics understand the phenomenon of lunar phases better than the average of university students. En estese artículo se describe la elaboración de una prueba de opción múltiple sobre las fases de la Luna y se analizan los resultados de su aplicación en diez grupos de estudiantes de Física de UFRGS. Durante el mejoramiento de la prueba observamos que el porcentaje de aciertos creció considerablemente cuando considerada una nueva redacción de la pregunta, destacando el cuidado que se debe tomar a fin de evitar respuestas incorrectas generadas por preguntas poco claras y no a causa de la ignorancia de los estudiantes sobre el tema. Confirmamos los resultados de otros estudios que las mayores dificultades de los alumnos sobre el tema fases de la Luna están en relacionar la fase de la Luna con su posición en el cielo en determinado momento. Por otra parte, nuestros resultados sugieren que, en general, los estudiantes de la Física comprenden mejor el fenómeno de las fases lunares que el promedio de los estudiantes universitarios. Neste artigo descrevemos a elaboração de um teste de múltipla escolha sobre as fases da Lua e analisamos os resultados de sua aplicação em dez grupos de estudantes de Física da UFRGS. Durante o aprimoramento do

  3. Sobre a largura da última superfície de espalhamento

    NASA Astrophysics Data System (ADS)

    Nobre, M. A. S.; Pires, N.; Lima, J. A. S.

    2003-08-01

    De acordo com o modelo do "Big-Bang", no universo primordial a matéria estava em equilíbrio térmico com a radiação. Com a expansão a temperatura da radiação cai. Quando a temperatura chega em torno dos 4.000K, os espalhamentos diminuem, começando a recombinação dos prótons e elétrons em Hidrogênio neutro (era conhecida como da recombinação). Ao final da recombinação, os fótons se propagam livremente sofrendo, em princípio, somente os efeitos do "redshift" cosmológico. Esses fótons nos alcançam hoje como a radiação cósmica de fundo (RCF), e parecem vir de uma superfície esférica ao nosso redor, tal que o raio dela é a distância que ele viajou desde seu último espalhamento na época da recombinação. Naturalmente, esse processo não ocorreu abruptamente, implicando na existência de uma largura no espaço dos "redshifts" que deve depender do modelo cosmológico específico e dos processos físicos considerados. Neste trabalho analisamos os efeitos de diferentes modelos - a saber, aqueles com decaimento do vácuo L(t), criação de matéria, quintessência e gás de Chaplygin - sobre a última superfície de espalhamento da RCF, em particular sua largura e a função visibilidade, que determina a probabilidade de um fóton ter tido seu último espalhamento num "redshift" z. No caso particular dos modelos com decaimento do vácuo, existe uma forte dependência da função visibilidade com L(t). Tais efeitos poderão ser testados através da análise dos resultados de experimentos mais precisos que estão atualmente em andamento, como por exemplo, o WMAP.

  4. Tendências de teses e dissertações sobre ensino de astronomia no Brasil

    NASA Astrophysics Data System (ADS)

    Bretones, P. S.; Megid Neto, J.

    2003-08-01

    Neste trabalho são apresentados os resultados de uma pesquisa do tipo estado da arte sobre teses e dissertações defendidas no Brasil e relativas ao ensino de Astronomia. Teve por objetivo identificar essa produção e conhecer as principais tendências da pesquisa nesse campo. O procedimento inicial consistiu de um levantamento bibliográfico junto ao Centro de Documentação em Ensino de Ciências (CEDOC) da Faculdade de Educação da UNICAMP e ao Banco de Teses da CAPES disponível na Internet. Foram localizadas 13 dissertações de mestrado e 3 teses de doutorado, as quais foram estudadas em função dos seguintes aspectos: instituição, ano de defesa, nível escolar abrangido no estudo, foco temático do estudo e gênero de trabalho acadêmico. Deste conjunto de pesquisas, 13 (81,3%) delas foram defendidas a partir da segunda metade dos anos 90, indicando uma preocupação mais recente com temas relativos ao ensino de Astronomia no conjunto da produção acadêmica em programas de pós-graduação no Brasil. Verificou-se que 43,7% dos trabalhos foram produzidas na USP e 18,8% na UNICAMP. Quanto ao nível escolar abrangido nos estudos, predominaram os estudos direcionados ao Ensino Fundamental de 5a a 8a séries (62,5%). No que diz respeito ao foco temático das pesquisas, as principais tendências voltaram-se: 56,3% para Conteúdo e Método; 43,8% para Concepções do Professor; 37,5% para Currículo e Programas; 37,5% para Recursos Didáticos. Quanto ao gênero de trabalho acadêmico, verificou-se que 43,8% são de Pesquisa Experimental e 31,3% de Pesquisa de Análise de Conteúdo. Estudos de revisão bibliográfica como este visam colaborar com a divulgação ampla da produção acadêmica em determinada área, traçando algumas de suas tendências. Ao mesmo tempo possibilita, a partir de investigações decorrentes, apontar as suas contribuições para o ensino e sinalizar com necessidades a serem supridas por futuras pesquisas.

  5. Reflexión bioética sobre el uso de organismos genéticamente modificados

    PubMed Central

    Yunta, Eduardo Rodríguez

    2011-01-01

    El presente artículo reflexiona desde los 4 principios de la bioética el uso comercial de organismos genéticamente modificados. Se cuestiona fundamentalmente la falta de transferencia de tecnología entre el mundo desarrollado y en desarrollo y el que el presente sistema de patentamiento de organismos vivos modificados fomenta intereses comerciales y no da debida importancia al desarrollo sostenible de la agricultura y ganadería en los países en desarrollo, donde más se necesita. Se reflexiona sobre la importancia que tiene evaluar los riesgos antes de introducirse en el mercado organismos genéticamente modificados y la necesidad de regulación en los países. PMID:21927675

  6. Educación sobre sexualidad y prevención del VIH: un diagnóstico para América Latina y el Caribe

    PubMed Central

    DeMaria, Lisa M.; Galárraga, Omar; Campero, Lourdes; Walker, Dilys M.

    2016-01-01

    RESUMEN Objetivo Mostrar, a través de un diagnóstico en América Latina y el Caribe, el panorama legislativo y curricular sobre sexualidad y prevención contra el virus de inmunodeficiencia humana (VIH) en el ámbito escolar, contrastándolo con los comportamientos sexuales reportados en encuestas demográficas y de salud. Métodos En mayo de 2008 se realizó, con el apoyo del Fondo de Población de las Naciones Unidas (UNFPA), una encuesta a informantes clave en 34 países de la Región. El cuestionario autoaplicado solicitó información sustantiva de agentes de las diferentes partes interesadas, como ministerios de educación y de salud, sobre los programas de prevención contra el VIH/Sida que se están aplicando en las escuelas. Resultados Respondieron a la encuesta 27 países que representan 95,5% de la población objetivo (6 a 18 años de edad). La mayoría de los países informó tener al menos un libro de texto o un capítulo específico para enseñar los temas de educación sobre sexualidad y prevención del VIH. En la escuela secundaria se cubren la mayor parte de los temas pertinentes relevantes para la educación sobre sexualidad, pero no todos. Por ejemplo, el problema de la discriminación por orientación o preferencia sexual no se incluye en los programas escolares. Conclusiones El material educativo sobre sexualidad debe ser revisado y actualizado periódicamente de modo que refleje los avances en los temas y en la forma de tratar los contenidos. En cada país el currículo debe abordar el tema del respeto a la diversidad sobre orientación, preferencia e identidad sexuales, y en particular el manejo apropiado de la educación para prevenir infecciones de transmisión sexual (ITS) en hombres que tienen sexo con hombres. Los esfuerzos de evaluación de la efectividad de los programas deben contemplar desenlaces tales como marcadores biológicos (incidencia y prevalencia de ITS y embarazo) y no únicamente indicadores de conocimiento y

  7. Tendências De Teses e Dissertações Sobre Educação em Astronomia No Brasil

    NASA Astrophysics Data System (ADS)

    Bretones, Paulo Sergio; Megid Neto, Jorge

    2005-07-01

    Apresentam-se os resultados de uma pesquisa do tipo estado da arte sobre teses e dissertações defendidas no Brasil e relativas ao ensino de Astronomia, com objetivo de identificar essa produção e conhecer as principais tendências da pesquisa nesse campo. Foram localizadas 13 dissertações de mestrado e 3 teses de doutorado, as quais foram estudadas em função dos seguintes aspectos: isntituição, ano de defesa, nível escolar abrangido no estudo, foco temático do estudo e gênero de trabalho acadêmico. Pretende-se assim colaborar com a divulgação ampla da produção acadêmica na área. Ao mesmo tempo o estudo possibilita, a partir de investigações decorrentes, apontar as contribuições dessa produção para o ensino e sinalizar com necessidades a serem supridas por futuras pesquisas.

  8. Sobre a atividade pós-periélica do cometa de órbita parabólica Yanaka (1988r)

    NASA Astrophysics Data System (ADS)

    de Almeida, A. A.; Sanzovo, G. C.; Boczko, R.

    2003-08-01

    Greenberg, Singh & de Almeida (ApJ, 414: L45-48, 1993) mostraram que a deficiência nas abundâncias observadas de C2 e CN no Cometa Yanaka (1988r) pode ser explicada em termos das propriedades dos seus componentes refratários orgânicos, além do fato que trata-se de um cometa dinamicamente novo, observado através de abertura de fenda pequena projetada muito próximo do núcleo. Neste trabalho, complementamos o estudo sobre a atividade deste cometa de órbita parabólica, através da determinação da lei de potência que exprime sua taxa de produção de H2O (o principal indicador de atividade) na fase pós-periélica, determinamos o raio nuclear efetivo mínimo com sua fração de área ativa e analisamos a emissão de partículas de poeira observadas no contínuo em 625,0 nm.

  9. Cambios históricos en el aporte terrígeno de la cuenca del Río de la Plata sobre la plataforma interna Uruguaya

    NASA Astrophysics Data System (ADS)

    Marrero, Analía; Tudurí, Adriana; Pérez, Laura; Cuña, Caroline; Muniz, Pablo; Lopes Figueira, Rubens; Michaelovitch de Mahiques, Michel; Alves de Lima Ferreira, Paulo; Pittauerová, Daniela; Hanebuth, Till; García Rodríguez, Felipe

    2014-12-01

    B 13813-4. También se determinó una mayor acumulación de sedimentos a través del tiempo en el cinturón de barro del Río de la Plata (plataforma continental adyacente), comparado con aquel registrado en la Barra del Indio (límite entre zona intermedia y externa del estuario). Estas diferencias podrían estar relacionadas con la influencia del Río de la Plata, el cual genera un ambiente altamente dinámico sobre la Barra del Indio y un ambiente más estable sobre el cinturón de barro en la plataforma continental.

  10. Desarrollo de la Escala sobre el Estigma Relacionado con el VIH/SIDA para Profesionales de la Salud mediante el uso de métodos mixtos123

    PubMed Central

    Varas-Díaz, Nelson; Neilands, Torsten B.; Guilamo-Ramos, Vincent; Cintrón Bou, Francheska N.

    2009-01-01

    El estigma relacionado con el VIH/SIDA continúa siendo un obstáculo para la prevención primaria y secundaria del VIH. Las consecuencias para las personas que viven con la enfermedad han sido muy documentadas y continúan siendo una gran preocupación para las personas que proveen servicios de salud y para aquellas que investigan el tema. Estas consecuencias son preocupantes cuando el estigma emana de profesionales de la salud porque se puede limitar el acceso a los servicios. Uno de los principales obstáculos para la investigación del estigma relacionado con el VIH en Puerto Rico es la falta de instrumentos cuantitativos para evaluar las manifestaciones del estigma entre profesionales de la salud. El objetivo principal de este estudio fue desarrollar y probar las propiedades psicométricas de una escala sobre el estigma relacionado con el VIH/SIDA culturalmente apropiada para personas que proveen servicios de salud puertorriqueñas y desarrollar una versión corta de la escala que pudiera usarse en escenarios clínicos con tiempo limitado. El instrumento desarrollado estuvo basado en evidencia cualitativa recopilada entre profesionales y estudiantes de profesiones de la salud puertorriqueños/as (n=80) y administrado a una muestra de 421 profesionales de la salud en adiestramiento. La escala contenía 12 dimensiones del estigma relacionado con el VIH/SIDA. El análisis cuantitativo corroboró 11 de ellas, teniendo como resultado un instrumento con validez y confiabilidad satisfactoria. Estas dimensiones, a su vez, fueron subcomponentes de un factor de estigma general superior. PMID:20333258

  11. Estudio del comportamiento acustico de recubrimientos de suelo derivados de la madera

    NASA Astrophysics Data System (ADS)

    Gadea Borrell, Jose Maria

    This work describes a study of the vibroacoustic behaviour of laminate flooring and is partly accomplished by means of an experimental method somewhat simpler than that normally used at the present time and partly by a hybrid FEM-FDTD numerical method that reproduces the proposed experiment. The experimental configuration records the sounds emitted by laminate floors when impacted and the numerical method allows the sound produced by the laminate floor to be determined before installation by previously reproducing its sound. The registers obtained from both methods are evaluated from the psychoacoustic perspective with the aim of determining the relevant parameters involved in their perception, and thus provide a method of distinguishing the effect of the different component materials on the sound produced by this type of floor covering. In the field of building acoustics, with which this work is involved, laminate flooring is seen as a good solution for deadening the noise of impacts. This question has now become important due to stricter building acoustic regulations (DB-HR Proteccion frente al ruido" del Codigo Tecnico de la Edificacion, CTE). Laminate floors possess the advantage that they can be installed over existing floor coverings. Their lightness, which adds little additional strain to structures, and the fact that they are easy to fit, make them an attractive solution at the present time and gives them promising prospects for the future. Of the different types available, synthetic laminate floors are now the most popular by far in almost all types of building and for this reason research is being carried out on the users' opinion of their quality and convenience. Among the factors that affect the latter quality is their acoustic behaviour as regards both the insulation of sound transmitted to neighbouring rooms and the sound reflected from the floor in the room in which it is installed. The conclusions reached in this work are related to the latter aspect, known as acoustic conditioning, rather than with acoustic insulation. Synthetic laminate floors are made of extremely rigid materials normally fitted over an underlay of softer material to improve thermal and acoustic behaviour and also make them more comfortable to walk on due to the underlay's shock-absorbing properties. This paper proposes a method of characterising synthetic laminate floors to provide an evaluation of the acoustic and psychoacoustic behaviour of the sound produced by the floor inside the room in which it is emitted. As has already been indicated, an experimental model is proposed to carry out tests on different combinations of synthetic laminate flooring and underlay materials. Sound registers are obtained directly from the experimental models by means of a measuring microphone and the psychoacoustic parameters that determine the acoustic qualities as perceived by human subjects are then determined. At the same time as these experiments are being carried out and analysed, a numerical model is implemented based on a combination of the finite elements method (FEM) and the finite difference in the time domain method (FDTD). This procedure is based on a finite elements 3D model with fluid-structural interaction to solve the dynamic problem caused by an impact. The velocity of each surface node is obtained from this model. By applying the method of finite difference in the time domain (FDTD), these velocities provide the sound pressure level at any point, according to the position of the microphone. This experiment enables different types of flooring to be characterised before they are fitted, provided that their mechanical characteristics (elastic modules and loss factors) are known. The subsequent processing of the sound archives obtained from the numerical experiment provides a method of identifying similarities between the results obtained from the physical experiment and those of the numerical model, thus demonstrating that it is possible to determine the acoustic quality of different types of flooring materials by numerical simulat

  12. Investigaccion-accion en la sala de clases sobre las creencias de la cultura de la ciencia de un grupo de estudiantes universitarios y su relacion reciproca con el aprendizaje de las ciencias biologicas

    NASA Astrophysics Data System (ADS)

    Cordova-Santiago, Lizzette Astrid

    La investigacion---accion que se llevo a cabo en la sala de clases tenia como punto de partida las creencias de la cultura de la ciencia de un grupo de estudiantes universitarios para luego examinar sus implicaciones en el proceso de aprendizaje de las Ciencias Biologicas. ¿Que se supone que hagan las creencias en relacion con el aprendizaje? ¿En que consiste incorporar este aspecto a la practica educativa universitaria? Utilizando el modelo de Kemmis y McTaggart (1987) la investigacion-accion se planteo como un proceso dinamico en cuatro momentos en espiral constituidos por la planificacion, la accion, la observacion y la reflexion. Cada una de las fases tuvo una intencion retrospectiva y prospectiva formando una espiral de autorreflexion del conocimiento y la accion. Se llevaron a cabo audio grabaciones en clases y analisis de documentos. Ademas, la profesora-investigadora hizo un portafolio para reflexionar sobre las creencias de la cultura de la ciencia que tienen los estudiantes y las creencias del aprendizaje que tiene la profesora y sobre como la comprension de estos elementos ayudo a mejorar su practica educativa a traves del tiempo. Los resultados obtenidos apuntan a que las creencias de la cultura de la ciencia que tiene el grupo de estudiantes son diversas. Ellos si creen que la ciencia tiene una cultura la cual describieron como: complicada y desconocida que evoluciona constantemente, que es un conjunto de metodos, que es altamente tecnologica, que resuelve problemas de salud, ayuda a interpretar la realidad del mundo que los rodea y su origen y que existen unas intersecciones entre la ciencia y el poder. Sobre las creencias del proceso de aprendizaje de la profesora-investigadora, estas senalan que el modelaje de actores, la vision de la academia que tiene ella asi como la participacion y negociacion entre todos los involucrados en el proceso educativo, son factores que inciden en el proceso de aprendizaje.

  13. La utilizacion de los mapas conceptuales en la ensenanza de biologia y su efecto sobre el dominio del proceso de fotosintesis en los estudiantes universitarios

    NASA Astrophysics Data System (ADS)

    Gonzalez Rivera, Maria M.

    Se investigo el efecto de los mapas conceptuales sobre el dominio del proceso de fotosintesis en estudiantes universitarios. La investigacion utilizo dos estrategias: mapas conceptuales individuales y mapas conceptuales colaborativos, con el fin de investigar si existen diferencias significativas en el dominio del proceso de fotosintesis. El analisis de los datos incluyo aspectos cualitativos y cuantitativos. Se desprende del estudio que el 80% de los estudiantes describen la utilizacion de los mapas conceptuales como una experiencia beneficiosa. El 70% de los estudiantes expreso que los mapas conceptuales son utiles en el aprendizaje del proceso de fotosintesis y el 61% indico que facilitan la comprension de los conceptos. Los hallazgos mas importantes del analisis cuantitativo indican que los estudiantes que utilizaron los mapas conceptuales mejoraron significativamente su desempeno en la posprueba global. Se utilizo la prueba Mann-Whitney para investigar si existian diferencias significativas en la posprueba y preprueba global, el valor de W = 1945.0, para un valor p de 0.00, lo cual establece diferencias significativas. Para determinar si existian diferencias significativas entre la posprueba y preprueba del grupo individual, se realizo la prueba nuevamente. El valor de W correspondio a 490.5, que es significativo, con un valor p de 0.00. Se concluye que existen diferencias significativas entre la ejecucion de la posprueba y preprueba del grupo individual. Los datos proveen suficiente evidencia para sostener que los estudiantes que utilizaron la estrategia de mapas conceptuales individuales mejoraron el dominio del proceso de fotosintesis significativamente. Se realizo nuevamente la prueba para los resultados de posprueba y preprueba del grupo colaborativo. El valor de W correspondio a 446 con un valor p de 0.00. Se concluyo que existen diferencias significativas entre la ejecucion de la posprueba y preprueba del grupo colaborativo. Finalmente, se efectuo una

  14. Distinción Empírica Entre Engagement y Trabajolismo en Enfermeras Hospitalarias de Japón: Efecto Sobre la Calidad del Sueño y el Desempeño Laboral

    PubMed Central

    Kubota, Kazumi; Shimazu, Akihito; Kawakami, Norito; Takahashi, Masaya; Nakata, Akinori; Schaufeli, Wilmar B.

    2016-01-01

    Objetivo El objetivo de este estudio es demostrar la distinción entre engagement y trabajolismo, estudiando su relación con la calidad del sueño y el desempeño laboral. Método Un total de 447 enfermeras de 3 hospitales de Japón fueron entrevistadas mediante un cuestionario autoadministrado que incluía la escala Utrecht (UWES, Utrecht Work Engagement Scale), la Escala de Adicción al Trabajo Holandesa (DUWAS, Dutch Workaholism Scale), preguntas sobre la calidad del sueño (7 ítems) con respecto a (1) dificultad para conciliar el sueño, (2) dificultad para mantener el sueño, (3) despertar temprano por la mañana, (4) dormirse o tomar siestas durante el día, (5) somnolencia diurna excesiva en el trabajo, (6) dificultad para despertarse por la mañana, y (7) despertar cansado en la mañana, y el Cuestionario sobre Salud y Desempeño (CSD) de la Organización Mundial de la Salud. Resultados Los modelos de ecuaciones estructurales demostraron que el engagement se relaciona positivamente con la calidad del sueño y el rendimiento laboral, mientras que el trabajolismo tiene una relación negativa con la calidad del sueño y el desempeño laboral. Conclusión Los resultados indican que el engagement y el trabajolismo son conceptualmente diferentes. El primero tiene una connotación positiva, mientras que el segundo se asocia de manera negativa al bienestar (buena calidad del sueño y buen rendimiento en el trabajo). PMID:26752805

  15. Estudio de la estructura logica utilizada en la ensenanza y el aprendizaje de los conceptos sobre el comportamiento de gases en el curso introductorio de quimica a nivel universitario

    NASA Astrophysics Data System (ADS)

    Costa Diaz, Agnes

    El estudio que se presenta es de caracter cualitativo, un estudio multicasos donde se estudia la estructura logica utilizada por cuatro (4) profesores universitarios que ensenan el curso introductorio de quimica, en la planificacion, presentacion y evaluacion del tema sobre el comportamiento de los gases. Se utilizaron varias fuentes de informacion como: cuestionarios de profesores y estudiantes, entrevistas, grabaciones videomagnetofonicas, materiales didacticos y una prueba conceptual, entre otros. La informacion recopilada fue analizada de acuerdo al orden logico del contenido presentado, el estilo de ensenanza del profesor, las tecnicas y estrategias utilizadas para el desarrollo de destrezas de pensamiento, el ambiente fisico en el salon de clase y los instrumentos de evaluacion y avaluo. El estudio demuestra que lo que los profesores piensan y planifican para hacer sus presentaciones no necesariamente es lo que ocurre en el salon de clases. El desarrollo de destrezas de pensamiento, que constituye una prioridad de los profesores, no se elaboran efectivamente. El uso de las estrategias de resolucion de problemas numericos predomino. La participacion del estudiante en el salon de clases fue limitada y no se logro demostrar el desarrollo de las destrezas de pensamiento deseadas. Aunque los profesores tienen su propio estilo de ensenanza, el orden logico del contenido presentado en clase fue el mismo o siguio muy de cerca el orden establecido por el libro de texto. Los profesores utilizaron preferentemente la tiza y la pizarra para sus presentaciones y la dinamica en el salon de clases fue esencialmente tradicional. Los profesores hicieron su presentacion y los estudiantes copiaron pasivamente la informacion. Las evaluaciones de los estudiantes fueron esencialmente, pruebas escritas de seleccion multiple de acuerdo con el estilo en que se les enseno. El avaluo fue casi inexistente. La prueba conceptual administrada revela un aprendizaje pobre en los conceptos mas

  16. High School Student's Alternative Conceptions About the Phenomenon of the Formation of the Moon Phases. (Spanish Title: Concepciones Alternativas de Alumnos de Educación Media Sobre el Fenómeno de Formación de las Fases de La Luna.) Concepções Alternativas de Alunos do Ensino Médio Sobre o Fenômeno de Formação das Fases da Lua

    NASA Astrophysics Data System (ADS)

    Iachel, Gustavo; Langhi, Rodolfo; Fernandes Scalvi, Rosa Maria

    2008-07-01

    Forty students, at ages between 14 and 18 years old, from three schools in Bauru city, were questioned about their alternative conceptions concerning the phenomenon of formation of the Moon Phases. It was observed that some of the pupils confound the phenomenon of the formation of the Moon Phases with the phenomenon of the formation of the lunar eclipses, others are unaware of the reason of the phenomenon, they present incoherent alternative conceptions of the reality or incomplete conceptions. The results found here are aimed at the teachers of Elementary Education and can be used as a subsidy for future development of new pedagogical methods. Cuarenta estudiantes, con edad entre 14 y 18 años, pertenecientes a tres escuelas de la ciudad de Bauru, fueron cuestionados sobre sus concepciones alternativas acerca del fenómeno de la formación de las fases de la Luna. Fue observado que algunos alumnos confunden el fenómeno de formación de las fases de la Luna con el fenómeno de formación de los eclipses lunares, otros desconocen el motivo delfenómeno, presentan concepciones alternativas incoherentes con la realidad o bien presentan concepciones incompletas. Los resultados aquí encontrados son destinados a los profesores de la Enseñanza Básica y podrán ser usados como ayuda para el futuro desarrollo de nuevos métodos pedagógicos. Quarenta estudantes, com idades entre 14 e 18 anos, pertencentes a três escolas da cidade de Bauru, foram questionados sobre suas concepções alternativas acerca do fenômeno de formação das fases da Lua. Foi observado que alguns dos alunos confundem o fenômeno da formação das fases da Lua com o fenômeno da formação dos eclipses lunares, outros desconhecem o motivo do fenômeno, apresentam concepções alternativas incoerentes com a realidade ou então concepções incompletas. Os resultados aqui encontrados são destinados aos professores do Ensino Básico e poderão ser usados como subsídio parafuturo desenvolvimento de

  17. [The Spanish AIDS Study Group and Spanish National AIDS Plan (GESIDA/Secretaría del Plan Nacional sobre el Sida) recommendations for the treatment of tuberculosis in HIV-infected individuals (Updated January 2013)].

    PubMed

    Rivero, Antonio; Pulido, Federico; Caylá, Joan; Iribarren, José A; Miró, José M; Moreno, Santiago; Pérez-Camacho, Inés

    2013-12-01

    This consensus document was prepared by an expert panel of the Grupo de Estudio de Sida (GESIDA [Spanish AIDS Study Group]) and the Plan Nacional sobre el Sida (PNS [Spanish National AIDS Plan]). The document updates current guidelines on the treatment of tuberculosis (TB) in HIV-infected individuals contained in the guidelines on the treatment of opportunistic infections published by GESIDA and PNS in 2008. The document aims to facilitate the management and treatment of HIV-infected patients with TB in Spain, and includes specific sections and recommendations on the treatment of drug-sensitive TB, multidrug-resistant TB, and extensively drug-resistant TB, in this population. The consensus guidelines also make recommendations on the treatment of HIV-infected patients with TB in special situations, such as chronic liver disease, pregnancy, kidney failure, and transplantation. Recommendations are made on the timing and initial regimens of antiretroviral therapy in patients with TB, and on immune reconstitution syndrome in HIV-infected patients with TB who are receiving antiretroviral therapy. The document does not cover the diagnosis of TB, diagnosis/treatment of latent TB, or treatment of TB in children. The quality of the evidence was evaluated and the recommendations graded using the approach of the Grading of Recommendations Assessment, Development and Evaluation Working Group. PMID:23541879

  18. Efectos combinados de la ampliación de la atención primaria de salud y de las transferencias condicionadas de dinero en efectivo sobre la mortalidad infantil en Brasil, 1998–2010*

    PubMed Central

    Guanais, Frederico C.

    2015-01-01

    Objetivos. Examiné los efectos combinados del acceso a la atención primaria mediante el Programa de Salud Familiar (PSF) y las transferencias condicionadas de dinero en efectivo del Programa Bolsa Familia (PBF) sobre la mortalidad infantil posneonatal (MIPN) en Brasil. Métodos. Empleé un análisis ecológico longitudinal usando datos en panel de 4 583 municipios brasileños de 1998 al 2010, con 54 253 observaciones en total. Estimé modelos de regresión de efectos fijos por mínimos cuadrados ordinarios, con la tasa de MIPN como la variable dependiente y el PSF, el PBF y sus interacciones como las principales variables independientes de interés. Resultados. La asociación de una mayor cobertura del PSF con una menor tasa de MIPN se volvió más fuerte conforme aumentaba la cobertura del PBF. En los promedios de todas las demás variables, cuando la cobertura de PBF era 25%, la MIPN predicha fue 5,24 (intervalo de confianza [IC] de 95% = 4,95, 5,53) para una cobertura del PSF de 0%, y de 3,54 (IC de 95% = 2,77, 4,31) para una cobertura del PSF de 100%. Cuando la cobertura del PBF era de 60%, la MIPN predicha fue 4,65 (IC de 95% = 4,36, 4,94) para una cobertura del PSF de 0%, y de 1,38 (IC de 95% = 0,88, 1,89) para una cobertura del PSF de 100%. Conclusiones. El efecto del PSF depende de la ampliación del PBF. Para las poblaciones empobrecidas y subatendidas, la combinación de intervenciones tanto del lado de la oferta como del lado de la demanda podría ser necesaria para mejorar los resultados en salud.

  19. High School Students' Previous Knowledge about the Stars. (Spanish Title: Conocimientos Previos de Estudiantes de Secundaria Acerca de Las Estrellas.) O Conhecimento Prévio de Alunos do Ensino Médio sobre as Estrelas

    NASA Astrophysics Data System (ADS)

    Iachel, Gustavo

    2011-12-01

    Based on the readings of articles related to Astronomy Education published in Brazil, it was noticed a lack of research on previous knowledge of students about the physical characteristics of stars, a fact that motivated us to develop this study. Previous knowledge of 125 students (approximated 15 years old) constituted the study sample; data was collected through written questionnaires (Appendix A) for analysis. From the content analysis of these responses it was possible to achieve some inferences as, for example, many students have some difficult to develop an explanatory model on the functioning of a star; there are few who say that the stars have a certain length of existence; some students have said that stars have tips; few recognize that a star is formed by a mass of gas; some previous knowledge come from purely visual aspects; furthermore, some students do not have the habit of observing nature in detail. We see this research as a reference in which science teachers can recognize the importance of previous knowledge for practice teaching and acquire resources for planning their lessons. De la lectura de artículos relacionados con la Educación en Astronomía publicados en el Brasil, se encuentra una falta de investigaciones acerca del conocimiento previo de los estudiantes sobre las características físicas de las estrellas, hecho que nos motivó a desarrollar este estudio. Los datos analizados se obtuvieron al aplicar un cuestionario a 125 estudiantes de secundaria, para posteriormente realizar un análisis de contenido, tal cuestionario se presenta en el Anexo A. Al realizar el análisis de contenido de las respuestas obtenidas, fue posible hacer algunas inferencias, como por ejemplo; muchos estudiantes tienen dificultades para desarrollar un modelo explicativo acerca del funcionamiento de una estrella; pocos estudiantes dicen que las estrellas tienen un cierto tiempo de vida; algunos estudiantes imaginan que las estrellas tienen puntas; pocos

  20. Reflecting on Character (Reflexionando Sobre el Caracter).

    ERIC Educational Resources Information Center

    Candelaria, Cordelia

    1980-01-01

    Responding to the "Proyecto Resolana" article in the July/August 1980 issue of this journal, the article notes the heterogeneity of Hispanic Americans, the three main effects of the European conquest on people of the Western Hemisphere, and attempts to further define the character of Hispanic Americans. (SB)

  1. Reflecting on Language. (Reflexionando Sobre el Idioma.)

    ERIC Educational Resources Information Center

    Mazas, Jose Garcia

    1980-01-01

    Covering a 500-year span, this article traces the changes in and evolution of the Spanish language from its earliest written accounts in the eleventh century to the Spanish that was brought by the Conquistadores to the New World. (DS)

  2. Reflecting on Culture. (Reflexionando Sobre la Cultura.)

    ERIC Educational Resources Information Center

    Irizarry, Estelle

    1980-01-01

    The article comments on two articles, previously published in the same journal, which address the relationship between the "little" cultural tradition of Chicanos, Cubans, and Puerto Ricans and the "great" tradition of Hispanic arts and letters. Notes similarities among these groups and calls for the banding together of Hispanic artists. (SB)

  3. Sobre | Smokefree Español

    Cancer.gov

    Espanol.smokefree.gov ofrece apoyo y recursos para norteamericanos que hablan español y quieren dejar de fumar. Este sitio en la red fue creada por la División de Investigación para el Control del Tabaco del Instituto Nacional del Cáncer.

  4. Nota sobre "Neblina" (Notes on "Neblina")

    ERIC Educational Resources Information Center

    De Bruyne, Jacques

    1974-01-01

    Suggests that the Royal Spanish Academy change the definition of "neblina" in the next edition of the "Dictionary of the Spanish Language" to "niebla ligera" or "light fog," and cites literary usage in support. (Text is in Spanish.) (CK)

  5. Learning about the Sky from the Environment: An Experience Working Along One Year with Students of Elementary Education. (Spanish Title: Aprendiendo sobre EL Cielo Desde el Entorno: Una Experiencia Trabajando Durante un Año Junto a Estudiantes del Primario.) Aprendendo sobre o Céu a Partir do Entorno: Uma Experiência de Trabalho ao Longo de um Ano com Alunos de Ensino Fundamental

    NASA Astrophysics Data System (ADS)

    Longhini, Marcos Daniel; Gomide, Hanny Angeles

    2014-12-01

    Research developed with 95 students of the 6th year of elementary education in a public school of Uberlândia, Minas Gerais. It was a continuous work from February to December 2013, which led the students to participate in activities of observation of the environment, specifically the sky, analyzing the changes occurred. We focused on the study of variations in temperature, rainfall, day length, variations in the size of the shadows and changes in the aspect of the Moon. Our focus of analysis targeted the discussion of the knowledge that these students had about the topics indicated and as they entered the stage during the implementation of the proposal. The results showed a limited perception that students have of their environment, however, lately expanded due to the undertaken activities, especially in relation to the Moon. Working with systematic measure procedures reveals the careful handling of data so that they become understandable to students, and working with the shadows points towards the students first understand how shadows are formed, and then apply this knowledge to Astronomy. Finally, we conclude that the lived process consisted of an initial step of a work that should be encouraged for the subsequent years of training of these students. Proyecto de investigación desarrollado con 95 alumnos del sexto año de primaria en una escuela pública de Uberlândia, Minas Gerais. Fue un trabajo continuo, de febrero a diciembre de 2013, que llevó a los estudiantes a participar en actividades de observación de su entorno, entre ellas, el cielo, analizando los cambios ocurridos. Nos centramos en el estudio de las variaciones en la temperatura, las precipitaciones, la duración del día, las variaciones en el tamaño de las sombras y los cambios en los aspectos de la Luna. Nuestro foco de análisis se centró en discutir el conocimiento que estos estudiantes tenían sobre los temas indicados al inicio y término de la propuesta. Los resultados mostraron una

  6. A Proposed Activity for a Meaningful Learning about the Moon Phases. (Breton Title: Uma Proposta de Atividade Para a Aprendizagem Significativa sobre as Fases da Lua.) Una Actividad Propuesta Para EL Aprendizaje Significativo Acerca de Las Fases de la Luna

    NASA Astrophysics Data System (ADS)

    Martins, Bruno Andrade; Langhi, Rodolfo

    2012-12-01

    This paper presents one of the concepts of Astronomy and its consequent failure in teaching this topic in high school, even when the official documents point out the necessity of Astronomy teaching at this school level. Among the spontaneous conceptions in Astronomy that high school students carry with them, even after the end of the school, we emphasized in this research the Moon phases. The development of different strategies in relation to traditional methods, aimed to teaching-learning process on this topic was considered in this study. These strategies were devised based on the reference frame of the Meaningful Learning, as elaborated by Ausubel. The proposals presented here include the active participation of students in experimental activities and other didactic activities, for their continuous evaluation during the process. These activities finished with a Comics elaboration about the Moon phases. Therefore, the objective of this paper is to present a proposal for differentiated teaching activity about Moon phases supported by the theoretical principles of Meaningful Learning at Physics classes. Este texto foca um dos conteúdos de Astronomia e a consequente falha no ensino deste tema no ensino médio, apesar de os documentos oficiais apresentarem a necessidade de se trabalhar a Astronomia neste nível de ensino. Dentre as concepções alternativas em Astronomia que os alunos do ensino médio carregam consigo, mesmo após o término dos estudos, destacamos, nesta pesquisa, o fenômeno das fases da Lua. O desenvolvimento de estratégias diferenciadas em relação ao ensino tradicional, visando o processo de ensino-aprendizagem sobre este tema, foi contemplado neste trabalho como um dos resultados obtidos sob a luz dos referenciais da aprendizagem significativa, fundamentados em Ausubel. Segundo a proposta aqui apresentada, a participação ativa dos alunos na execução de uma atividade experimental e outras atividades didáticas, que visam sua cont

  7. Experiencias sobre el impacto del Programa de Formación en Ética de la Investigación Biomédica y Psicosocial en el ámbito de la salud mental y la investigación conductual.

    PubMed

    Barrios, Liliana Mondragón

    2012-01-01

    El propósito de este trabajo es presentar el impacto y la integración que los conocimientos adquiridos en el Programa Internacional de Formación en Ética de la Investigación Biomédica y Psicosocial de la Universidad de Chile han tenido en mi experiencia profesional, en el ámbito de la investigación psicosocial en un Instituto de Salud de México. Para este objetivo, expondré tres áreas en las cuales se ha podido evidenciar tal impacto: trabajo en los comités de ética, desarrollo de programas de académicos en bioética e investigación y publicación sobre ética y bioética. El motivo que me llevó a incursionar en el Programa fue que su enseñanza vincula la investigación psicosocial con la ética y la bioética, lo cual me permitió dirigir este tipo de reflexión hacia problemas como violencia, suicidio, adicciones, depresión y salud mental, y a nuevos campos como los estudios comunitarios, con poblaciones en riesgo o vulnerables, en los cuales las diversas implicaciones son difíciles de indagar. PMID:22754085

  8. Experiencias sobre el impacto del Programa de Formación en Ética de la Investigación Biomédica y Psicosocial en el ámbito de la salud mental y la investigación conductual

    PubMed Central

    Barrios, Liliana Mondragón

    2012-01-01

    El propósito de este trabajo es presentar el impacto y la integración que los conocimientos adquiridos en el Programa Internacional de Formación en Ética de la Investigación Biomédica y Psicosocial de la Universidad de Chile han tenido en mi experiencia profesional, en el ámbito de la investigación psicosocial en un Instituto de Salud de México. Para este objetivo, expondré tres áreas en las cuales se ha podido evidenciar tal impacto: trabajo en los comités de ética, desarrollo de programas de académicos en bioética e investigación y publicación sobre ética y bioética. El motivo que me llevó a incursionar en el Programa fue que su enseñanza vincula la investigación psicosocial con la ética y la bioética, lo cual me permitió dirigir este tipo de reflexión hacia problemas como violencia, suicidio, adicciones, depresión y salud mental, y a nuevos campos como los estudios comunitarios, con poblaciones en riesgo o vulnerables, en los cuales las diversas implicaciones son difíciles de indagar. PMID:22754085

  9. The Meanings of Astronomical Observation: An Analysis on the Basis of Relationship with Knowledge. (Spanish Title: Los Sentidos de la Observación Astronómica: un Análisis sobre la Base de la Relación con el Saber.) Os Sentidos da Observação Astronômica: Uma Análise com Base na Relação com o Saber

    NASA Astrophysics Data System (ADS)

    Klein, Alberto Eduardo; de Mello Arruda, Sergio; Meneghello Passos, Marinez; Vinicius Domenes Zapparoli, Ferdinando

    2010-12-01

    This article presents results of a research which aimed to understand the meanings that people construct for astronomical observation. The subjects, students and school teachers, initially received some instruction on how to view astronomical objects through the telescope. After the observation was realized, they were interviewed. The data analysis allowed the creation of 12 categories, later interpreted on the basis of relationship with knowledge (relation to the world, with himself and with others), as presented by Bernard Charlot. Este artículo presenta los resultados de una investigación que tuvo como objetivo comprender los sentidos que las personas construyen para la observación astronómica. Los sujetos, los estudiantes y maestros de escuela, recibieron inicialmente algunas instrucciones sobre cómo ver los objetos astronómicos a través del telescopio. Al término de la observación, fueron entrevistados. El análisis de datos permitió la creación de 12 categorías que más tarde fueron interpretadas sobre la base de la relación con el conocimiento (relación con el mundo, consigo mismo y con los demás), tal como presentado por Bernard Charlot. Este artigo apresenta resultados de uma pesquisa que objetivou entender quais os sentidos que as pessoas constroem para a observação astronômica. Os sujeitos da pesquisa, estudantes e professores do ensino médio, receberam inicialmente alguma instrução sobre como visualizar os objetos astronômicos através do telescópio. Após a realização da observação, eles foram entrevistados. A análise dos dados permitiu a elaboração de 12 categorias que foram posteriormente interpretadas com base nas relações com o saber (relação com o mundo, consigo mesmo e com o outro), conforme apresentadas por Bernard Charlot.

  10. Mixed-Methods Study that Examines Nine Science Teachers' Perceptions of Slooh Robotic Telescope for Teaching Astronomy. (Breton Title: Métodos Mistos de Estudo que Examinam a Percepção de Nove Professores de Ciências sobre o Telescópio Robótico Slooh Para Ensino de Astronomia.) Métodos Mixtos de Estudio que Examinan la Percepcion de Nueve Profesores de Ciencias sobre EL Telescopio Robótico Slooh Para la Enseñanza de la Astronomía

    NASA Astrophysics Data System (ADS)

    Gershun, Daniel C.; Slater, Timothy F.; Berryhill, Katie J.

    2014-07-01

    Although previous studies show that robotic telescopes have the potential to enhance student learning, there is comparatively little research that focuses on teacher perceptions of this technology. This study investigates: "what is the academic merit of using SLOOH robotic telescopes to teach astronomy as perceived by science teachers?" Our sample consists of nine science teachers of students aged 13-18 years. Pre- and post-tests, interviews, and surveys were collected during two weeks of a summer online course about robotic telescopes. While pre and post-tests do not reveal a statistically significant gain in astronomy content knowledge, analysis of qualitative data reveals five themes which describe the most important aspects of using SLOOH according to participants: "Images," "Interface," "Classroom Application," "Instructor Impact," and "Logistical Issues." Analysis of these themes suggests that SLOOH can provide an interactive and social learning environment with capabilities to incorporate crossdisciplinary themes. Embora estudos anteriores mostram que os telescópios robóticos têm o potencial de melhorar a aprendizagem dos alunos, há relativamente pouca investigação focada nas percepções de professores a respeito desta tecnologia. Este estudo investiga: "qual é o mérito acadêmico da utilização de telescópios robóticos Slooh para ensinar astronomia, tal como percebido pelos professores de ciências?" Nossa amostra é composta por nove professores de ciências de estudantes com idades entre 13-18 anos pré e pós-testes, entrevistas, e levantamentos foram coletados durante duas semanas de um curso on-line de verão sobre telescópios robóticos. Enquanto os testes pré e pós não revelaram um ganho estatisticamente significativo no conhecimento do conteúdo astronomia, a análise de dados qualitativos revela cinco temas que descrevem os aspectos mais importantes da utilização Slooh de acordo aos participantes: "Imagens", "Interface", "Aplica

  11. Reflexiones Sobre Investigacion Educacional (Reflections on Educational Research).

    ERIC Educational Resources Information Center

    Valle, Victor M.

    Educational research can serve to improve education in both developed and developing countries. It can be oriented toward increasing knowledge about the educational reality, generating theories, or confirming immediate educational political decisions. Educational research should be an interdisciplinary undertaking; this variety helps to unify…

  12. Proposiciones Sobre Autonomia Universitaria. (Propositions on University Autonomy).

    ERIC Educational Resources Information Center

    Valle, Victor M.

    University autonomy is a concept widely discussed and often misunderstood. In the Latin American context, university autonomy has been regarded as something inherent to the nature of the universities. As long as universities exist, the phenomenon of university autonomy will be present . University autonomy should be examined in the light of such…

  13. Los ojos de la NASA sobre la Tierra

    NASA Video Gallery

    La NASA cuenta con más de una decena de satélites que estudian la Tierra. Conoce la información que recaban los satélites, junto con Gilberto Colón, asistente especial del subdirector del Centro de...

  14. Epilepsy. Fact Sheet = Epilepsia. Hojas Informativas Sobre Discapacidades.

    ERIC Educational Resources Information Center

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This fact sheet, written in both English and Spanish, provides a definition, information on incidence, typical characteristics, and educational implications of epilepsy. It notes that epilepsy is classified as "other health impaired" under the Individuals with Disabilities Education Act (IDEA) and that children with epilepsy or seizure disorders…

  15. Spina Bifida. Fact Sheet = Espina Bifida. Hojas Informativas Sobre Discapacidades.

    ERIC Educational Resources Information Center

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This fact sheet offers definitions of the three types of spina bifida (spina bifida occulta, meningocele, and myelomeningocele), outlines their incidence, describes characteristics of individuals with spina bifida, and reviews educational implications. The fact sheet discusses the need for many children with myelomeningocele to learn to manage…

  16. Emotional Disturbance. Fact Sheet = Problemas Emocionales. Hojas Informativas Sobre Discapacidades.

    ERIC Educational Resources Information Center

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This fact sheet, written in both English and Spanish, provides a definition, information on incidence, typical characteristics, and educational implications of emotional disturbance. The definition is from the Individuals with Disabilities Education Act (IDEA) and incidence in 1999-2000 is reported as about 470,000 children and youth. Educational…

  17. Estudios sobre Educacion, 2002 (Studies on Education, 2002).

    ERIC Educational Resources Information Center

    Estudios sobre Educacion, 2002

    2002-01-01

    This journal, which provides abstracts of its articles mostly in Spanish and a few in English, contains studies (estudios) and notes (notas) about educational issues, as well as relevant book reviews (recensiones). Studies in this issue (No. 3, 2002) are: "Unprotected Time of Early Adolescence and Intergenerational Relations: A New Educational…

  18. Estudios sobre Educacion, 2002 (Studies on Education, 2002).

    ERIC Educational Resources Information Center

    Estudios sobre Educacion, 2002

    2002-01-01

    This scholarly journal deals with the study of education. Articles in this second issue are: "La Vertebracion Academica de la Formacion Inicial del Profesorado" (The Academic Backbone of the Initial Formation of Teachers) (Jose M. Esteve); "Deficiencia Visual en el Nino" (Visual Deficiency in the Young Child) (Feli Peralta; Juan Narbona); "The…

  19. [Parenting Information. Informacion Sobre Como Ser Padres Mejores.

    ERIC Educational Resources Information Center

    Moreno, Steve

    These five booklets, containing information on how parenting can effect children's school achievement, are part of a series of 22 innovative booklets designed specifically to help parents understand and help their children learn. Booklet #1, "Parents--Teach Your Children to Learn [Before They Go to School]," defines intelligence and suggests…

  20. [Parenting Information: Teenagers. Informacion Para los Padres: Sobre los Jovenes.

    ERIC Educational Resources Information Center

    Moreno, Steve

    These four booklets are devoted specifically to the concerns of parents and their teenage children and are part of a series of 22 booklets designed specifically to help parents understand their children and help them to learn. "Parents--Learn about Your Teenager" (booklet #6) explains the changes which occur during the teen years and the reasons…

  1. Apuntes sobre Latinismos en Espanol (Notes on Latinisms in Spanish)

    ERIC Educational Resources Information Center

    Perez B., L. A.

    1977-01-01

    Several Latinisms appear in Latin American Spanish, which would logically be farther from its Latin roots than Spanish in Spain. The existence of these elements and their importance as linguistic facts is analyzed here. Four words are treated: "Cliente,""cuadrar,""cuarto" and "rabula." (Text is in Spanish.) (CHK)

  2. Um Olhar sobre "Beleza Americana" (A Look at "American Beauty").

    ERIC Educational Resources Information Center

    Bissoto, Maria Luisa

    2000-01-01

    Discusses the film "American Beauty" in light of a reading of Karl Marx. Finds that the film shows the circularity which marks bourgeois society, even though the rhythm of industry and renovation of the society masks it. States that Marx praises the industry, invention, and innovation of the bourgeoisie. (BT)

  3. [Parenting Information: Drugs. Informacion Para los Padres: Sobre las Drojas.

    ERIC Educational Resources Information Center

    Moreno, Steve

    These two booklets provide basic information about drugs and drug abuse and are part of a series of 22 booklets, designed specifically to help parents understand their children and help them to learn. "Let's Talk about Drug Abuse," (booklet #18), reviews foreign substances or drugs young people are often exposed to (i.e., tobacco, alcohol,…

  4. Iniciativa sobre Efectividad: Primeros frutos (Initiative about Effectiveness: First Fruits).

    ERIC Educational Resources Information Center

    Moreno Garcia, Teresa, Ed.

    2001-01-01

    This Spanish- and Portuguese-language bulletin is a follow-up to No. 15 (PS 030 558), which examined some Effectiveness Initiative (EI) projects. This issue presents some beginning efforts to reflect on what has been learned through EI and to draw conclusions. The articles cover the results of EI projects from such angles as their relations with…

  5. Questions about Brain Development = Preguntas sobre el desarrollo del cerebro.

    ERIC Educational Resources Information Center

    Southeastern Regional Vision for Education (SERVE), Tallahassee, FL.

    Noting that new research shows that a baby's earliest years shape how he or she grows later in life, this brochure, in English- and Spanish-language versions, provides brief answers to some important questions parents may have about their baby's brain. The questions answered are: (1) "Why is brain development a popular subject lately?; (2) "What…

  6. Memories of Astronomy Education in Brazil: Clippings from the Discourses of Interviewed Researchers on the Subject. (Spanish Title: Memorias de la Educación en Astronomía en Brasil: Recortes de los Discursos de Investigadores Entrevistados Acerca del Tema ) Memórias da Educação em Astronomia no Brasil: Recortes a Partir das Falas de Pesquisadores Entrevistados sobre o Tema

    NASA Astrophysics Data System (ADS)

    Iachel, Gustavo; Nardi, Roberto

    2014-12-01

    This paper presents a historical retrospective concerning data from a research in Astronomy Education in Brazil, after 1973. It was organized on the basis of the speech analysis of national researchers considered references in this field by their peers. Furthermore, it was elaborated on the basis of other studies from the areas of Science Education, Physics and Astronomy. This historical overview was developed in order to facilitate understanding of the contexts in which the interviewed researchers have developed professionally. Moreover, we attempted to recover the memory of the growing field of research in Astronomy Education in the country. We believe that the history presented can help those trying to understand the past in an attempt to resolve current and future demands. Se presenta en este artículo una retrospectiva histórica referente a datos provenientes de la investigación en enseñanza de la astronomía en el Brasil, después de 1973, organizada sobre la base del análisis de los discursos de los investigadores nacionales considerados referencias en este campo, y también en la lectura de las publicaciones en las áreas de Enseñanza de las Ciencias, Física y Astronomía. Este repaso histórico se desarrolló con el fin de facilitar la comprensión de los contextos en los que los investigadores entrevistados se han desarrollado profesionalmente. Por otra parte, se intentó recuperar la memoria del creciente campo de la investigación en Educación en Astronomía en el país. Creemos que el relato presentado puede contribuir a quien trata de comprender el pasado, en un intento de resolver las demandas actuales y futuras. Relata-se neste artigo uma retrospectiva histórica referente a dados provenientes de pesquisa em Educação em Astronomia no país, pós 1973, organizada com base na análise das falas de pesquisadores considerados referências nacionais nesse campo, como também na leitura de publicações das áreas de ensino de Ciências, F

  7. Changes in the properties of solonetzic soil complexes in the dry steppe zone under anthropogenic impacts

    NASA Astrophysics Data System (ADS)

    Lyubimova, I. N.; Novikova, A. F.

    2016-05-01

    Long-term studies of changes in the properties of solonetzic soil complexes of the dry steppe zone under anthropogenic impacts (deep plowing, surface leveling, irrigation, and post-irrigation use) have been performed on the Privolzhskaya sand ridge and the Khvalyn and Ergeni plains. The natural morphology of solonetzic soils was strongly disturbed during their deep ameliorative plowing. At present, the soil cover consists of solonetzic agrozems (Sodic Protosalic Cambisols (Loamic, Aric, Protocalcic)), textural (clay-illuvial) calcareous agrozems (Eutric Cambisols (Loamic, Aric, Protocalcic)), agrosolonetzes (Endocalcaric Luvisols (Loamic, Aric, Cutanic, Protosodic), agrochestnut soils (Eutric Cambisols (Siltic, Aric)), and meadowchestnut soils (Haplic Kastanozems). No features attesting to the restoration of the initial profile of solonetzes have been found. The dynamics of soluble salts and exchangeable sodium differ in the agrosolonetzes and solonetzic agrozems. A rise in pH values takes place in the middle part of the soil profiles on the Khvalyn and Ergeni plains.

  8. An English-Spanish Glossary of Terminology Used in Forestry, Range, Wildlife, Fishery, Soils, and Botany = Glosario en Ingles-Espanol de Terminologia Usada en Forestales, Pastizales, Fauna, Silvestre, Pesqueria, Suelos, y Botanica.

    ERIC Educational Resources Information Center

    Medina, Alvin Leroy

    This document presents English-Spanish/Spanish-English equivalent translations of scientific and management terms commonly used in the field of natural resource management. The glossary is composed of two sections. Section 1 contains the English to Spanish translations, while Section 2 provides the Spanish to English translations. Each section is…

  9. Ask about Chapter 1: Questions Parents Often Ask about Chapter 1 Programs = Pregunte sobre el capitulo 1: Preguntas que los padres frecuentemente hacen sobre el programa capitulo 1.

    ERIC Educational Resources Information Center

    RMC Research Corp., Hampton, NH.

    Chapter 1 is a program funded by the Federal Government to help children who are at a disadvantage in school. Parents have many questions about Chapter 1 programs. This brochure presents many of the questions that parents have asked over the years about how Chapter 1 works. Because every school district's Chapter 1 programs are different, the…

  10. Invertebrate fauna associated with Torpedograss, Panicum repens (Cyperales: Poaceae), in Lake Okeechobee, Florida, and prospects for biological control

    SciTech Connect

    Cuda, J.P.; Dunford, J.C.; Leavengood, J.M. Jr.

    2007-03-15

    realizado como parte de un estudio de factibilidad para determinar si conota es una candidata apropiada para un programa de control biologico clasico. En general, especimenes de aproximadamente unos 4,000 artropodos y unos 400 nematodos fueron recolectados. Muestras recolectadas pasando una red sobre vegetacion mezclada, cortando la vegetacion y tomando centros del suelo fueron dominados por representantes de artropodos de los ordenes de Hemiptera, Hymenoptera, Diptera, y Acari. Nematodos en el genero Pratylenchus, que causan lesiones sobre tejido, fueron asociados regularmente con las raices de conota. Ninguno de los organismos recolectados eran especialistas sobre conota. Aunque el control biologico clasico de la conota es factible basado sobre la magnitud de la infestacion, las perdidas economicas, la resistencia hacia los metodos de control convencionales y el informe en la India de un posible enemigo natural especifico a esta planta, la posicion botanica de este pasto maleza requiere una evaluacion de riesgo economico formal antes de continuar con un programa de control biologico clasico. (author)

  11. In Situ Persistence and Migration of Biochar Carbon and Its Impact on Native Carbon Emission in Contrasting Soils under Managed Temperate Pastures

    PubMed Central

    Singh, Bhupinder Pal; Fang, Yunying; Boersma, Mark; Collins, Damian; Van Zwieten, Lukas; Macdonald, Lynne M

    2015-01-01

    Pyrogenic carbon (PyC) is an important component of the global soil carbon (C) pool, but its fate, persistence, and loss dynamics in contrasting soils and environments under planted field conditions are poorly understood. To fill this knowledge gap, a 13C-labelled biochar, as a surrogate material for PyC, produced from Eucalyptus saligna by slow pyrolysis (450°C; δ13C -36.7‰) was surface (0−10 cm) applied in C3 dominated temperate pasture systems across Arenosol, Cambisol and Ferralsol. The results show a low proportion of the applied biochar-C mineralised over 12 months in a relatively clay- and C-poor Arenosol (i.e., 2.0% loss via mineralisation), followed by a clay- and C-rich Cambisol (4.6%), and clay-, C- and earthworm-rich Ferralsol (7.0%). The biochar-C mean residence time (MRT), estimated by different models, varied between 44−1079 (Arenosol), 18−172 (Cambisol), and 11−29 (Ferralsol) years, with the shorter MRT estimated by a one-pool exponential and the longer MRT by an infinite-pool power or a two-pool exponential model. The two-pool model was best fitted to biochar-C mineralisation. The biochar-C recovery in the 12−30 cm soil layer varied from between 1.2% (Arenosol), 2.5−2.7% (Cambisol) and 13.8−15.7% (Ferralsol) of the applied biochar-C after 8−12 months. There was a further migration of biochar-C below the 50-cm depth in the Arenosol, as the combined biochar-C recovery in the mineralised pool and soil profile (up to 30 or 50 cm) was 82%, in contrast to 101% in the Cambisol and 104% in the Ferralsol after 12 months. These results indicate that the downward migration of biochar-C was greatest in the Arenosol (cf. Cambisol and Ferralsol). Cumulative CO2-C emission from native soil-plant sources was lower (p <0.10) in the biochar-amended vs. non-amended Ferralsol. This field-based study shows that the downward migration of biochar-C exceeded its loss via mineralisation in the Arenosol and Ferralsol, but not in the Cambisol. It is thus

  12. Geo-pedological control of soil organic carbon and nitrogen stocks at the landscape scale

    NASA Astrophysics Data System (ADS)

    Barré, Pierre; Durand, Hermine; Chenu, Claire; Meunier, Patrick; Montagne, David; Castel, Géraldine; Billiou, Daniel; Cécillon, Lauric

    2015-04-01

    Geo-pedology, here defined as soil type (or Reference Soil Group) and parent material, can have a major impact on ecosystem (vegetation and soil) functioning. Geo-pedology can therefore deeply influence soil organic matter (SOM) stock. Nonetheless, the effect of geo-pedology on soil organic C (SOC) and N stocks has seldom been investigated. Indeed, factors known to influence SOM stocks such as land use and climate frequently co-vary with geo-pedology, so that testing the influence on SOM stocks of the factor "geo-pedology" alone is challenging. In this work, we studied SOM stocks of forest and cropland soils in a small landscape (17 km²) of the Paris basin (AgroParisTech domain, Thiverval-Grignon, France). We collected soil samples (0-30 cm) in 50 forest and cropland plots, located in five geo-pedological contexts: Luvisols developed on loess deposit, Cambisols developed on hard limestone, Cambisols developed on shelly limestone, Cambisols developed on chalk and Cambisols developed on calcareous clay deposits. We then determined SOM stocks (organic C and total N) and SOM distribution across different particle size fractions (coarse sand, fine sand and silt-clay). As expected, SOC stocks were much higher in forests (~ 83 tC ha-1) than in cultivated soils (~ 49 tC ha-1). Interestingly, Cambisols had higher SOC stocks than Luvisols (69 vs 56 tC ha-1) and the difference between SOC stocks in forest and cultivated soils was much higher for Cambisols compared to Luvisols. Within Cambisols, parent material did not influence SOC stocks but the interaction between parent material and land use was significant, indicating that the effect of land use on SOC stocks was modulated by parent material. Similar trends were observed for soil N stocks. Conversely, soil type and parent material did not control SOM distribution in soil size fractions, while forest soils showed a higher distribution of SOC and N in the sand-size fraction than cropland soils. Overall, our study evidenced

  13. In Situ Persistence and Migration of Biochar Carbon and Its Impact on Native Carbon Emission in Contrasting Soils under Managed Temperate Pastures.

    PubMed

    Singh, Bhupinder Pal; Fang, Yunying; Boersma, Mark; Collins, Damian; Van Zwieten, Lukas; Macdonald, Lynne M

    2015-01-01

    Pyrogenic carbon (PyC) is an important component of the global soil carbon (C) pool, but its fate, persistence, and loss dynamics in contrasting soils and environments under planted field conditions are poorly understood. To fill this knowledge gap, a 13C-labelled biochar, as a surrogate material for PyC, produced from Eucalyptus saligna by slow pyrolysis (450°C; δ13C -36.7‰) was surface (0-10 cm) applied in C3 dominated temperate pasture systems across Arenosol, Cambisol and Ferralsol. The results show a low proportion of the applied biochar-C mineralised over 12 months in a relatively clay- and C-poor Arenosol (i.e., 2.0% loss via mineralisation), followed by a clay- and C-rich Cambisol (4.6%), and clay-, C- and earthworm-rich Ferralsol (7.0%). The biochar-C mean residence time (MRT), estimated by different models, varied between 44-1079 (Arenosol), 18-172 (Cambisol), and 11-29 (Ferralsol) years, with the shorter MRT estimated by a one-pool exponential and the longer MRT by an infinite-pool power or a two-pool exponential model. The two-pool model was best fitted to biochar-C mineralisation. The biochar-C recovery in the 12-30 cm soil layer varied from between 1.2% (Arenosol), 2.5-2.7% (Cambisol) and 13.8-15.7% (Ferralsol) of the applied biochar-C after 8-12 months. There was a further migration of biochar-C below the 50-cm depth in the Arenosol, as the combined biochar-C recovery in the mineralised pool and soil profile (up to 30 or 50 cm) was 82%, in contrast to 101% in the Cambisol and 104% in the Ferralsol after 12 months. These results indicate that the downward migration of biochar-C was greatest in the Arenosol (cf. Cambisol and Ferralsol). Cumulative CO2-C emission from native soil-plant sources was lower (p <0.10) in the biochar-amended vs. non-amended Ferralsol. This field-based study shows that the downward migration of biochar-C exceeded its loss via mineralisation in the Arenosol and Ferralsol, but not in the Cambisol. It is thus important to

  14. Estudio de la influencia de la refrigeracion con aire de forma natural e inducida en el comportamiento de instalaciones fotovoltaicas

    NASA Astrophysics Data System (ADS)

    Mazon Hernandez, Rocio

    panels are analysed to compare and select the best configuration. The presented research provides a deep knowledge of how they work as well as information and results for an improvement in future designs of building integrated photovoltaic systems. Este estudio se centra en analizar la influencia negativa de la temperatura en la produccion electrica de paneles fotovoltaicos al estar emplazados sobre cubierta de acero, como sucede en naves industriales y sobre un invernadero. Se estudian diferentes configuraciones que permitan refrigerar los paneles, reduciendo su temperatura y mejorar su rendimiento. Para abordar este problema, se han construido dos instalaciones experimentales, fieles a plantas solares en funcionamiento. Una instalacion engloba dos paneles fotovoltaicos sobre estructura fija al suelo. Uno de los paneles esta integrado sobre una superficie paralela y metalica. Entre ambas superficies existe un espacio que posibilita circular aire, permitiendo refrigerar el panel por conveccion natural, o conveccion forzada impulsando el aire con un ventilador. El otro panel, libre por su cara posterior y se ha considerado de referencia. Se ha estudiado el comportamiento del panel integrado sobre cubierta para diferentes secciones de aire y velocidades inducidas, comparandolo con el panel de referencia. Se ha desarrollado un modelo experimental que nos permite determinar la temperatura del panel en funcion de las variables que influyen en su refrigeracion. Adicionalmente, se han analizado los datos de una planta solar en funcionamiento, con paneles de igual caracteristicas, obteniendo correlaciones entre la temperatura del panel y las variables electricas y comparandolos con las obtenidas en la instalacion experimental. La segunda instalacion experimental reproduce parte de una instalacion solar sobre un invernadero, formada por cuatro paneles fotovoltaicos colocados sobre el plastico del invernadero, existiendo un canal divergente entre ambas superficies. Se estudia la

  15. Impact of payments for environmental services and protected areas on local livelihoods and forest conservation in northern Cambodia

    PubMed Central

    Clements, Tom; Milner-Gulland, E J

    2015-01-01

    potenciales de los pagos por servicios ambientales (PSA) y áreas protegidas (APs) sobre los resultados ambientales y las subsistencias locales en los países en desarrollo son polémicos y se han debatido ampliamente. La evidencia disponible es escasa; ha habido pocas evaluaciones rigurosas de los impactos ambientales y sociales de las APs y particularmente los PSA. Medimos el impacto sobre los bosques y el bienestar humano en tres diferentes programas de PSA que se llevan a cabo dentro de dos APs en el norte de Camboya usando un panel de aldeas de intervención y controles emparejados. Tanto los PSA como las APs brindaron resultados ambientales adicionales en relación a los contrafácticos, esto quiere decir que redujeron las tasas de deforestación significativamente en relación a los controles. Las áreas protegidas incrementaron el acceso seguro a los recursos del suelo y el bosque para las viviendas locales, beneficiando a los usuarios de los recursos del bosque pero restringiendo la habilidad de las viviendas para expandirse y diversificar su agricultura. Los impactos de los pagos por servicios ambientales sobre el bienestar de las viviendas estuvieron relacionados con la magnitud de los pagos proporcionados. Los dos programas de PSA de mayor paga y con conexión al mercado tuvieron impactos positivos significativos, mientras que un programa de menor paga con el objetivo de proteger a la biodiversidad no tuvo un efecto detectable sobre las viviendas, a pesar de sus resultados ambientales positivos. Las viviendas que se inscribieron a los programas de PSA con mayor paga, sin embargo, necesitaban típicamente más bienes capitales, por lo que eran menos pobres y tenían mayor seguridad alimentaria que otros aldeanos. Por esto, mientras los impactos de las APs sobre el bienestar de las viviendas fueron limitados en general y variaron dependiendo de las estrategias de subsistencia, los programas de PSA tuvieron impactos positivos significativos sobre las viviendas para

  16. Questions Parents Ask about Schools = Preguntas que hacen los padres sobre las escuelas. Revised.

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC. Office of Intergovernmental and Interagency Affairs.

    Noting that parents play an important role in the school success of their elementary- and middle-school-aged children, this booklet offers research-based tips to provide both practical guidance and information about a range of education-related topics. Presented in a question-answer format in both English and Spanish versions, the booklet provides…

  17. Homework Tips for Parents = Consejos para los padres sobre la tarea escola.

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC. Office of Intergovernmental and Interagency Affairs.

    Homework has been a part of students' lives since the beginning of formal school in the United States; the push for increased homework has increased, fueled by rising academic standards. Noting that parents involved can have either a positive or a negative influence on the value of homework, this booklet, in both English and Spanish, offers…

  18. Recopilacion Bibliografica Sobre Investigacion y Cambio Cultural (Bibliographic Compilation about Cultural Investigation and Exchange).

    ERIC Educational Resources Information Center

    Centro Latinoamericano de Educacion de Adultos, Santiago (Chile).

    The bibliography forms part of a project to define guidelines for a method of cultural investigation in the education of adults. A brief introduction is followed by a list of libraries and the plan for the listing of entries in the bibliography. Entries are arranged alphabetically by author under the following general headings: background on the…

  19. Nueva investigacion sobre kindergarten de dia completo (Recent Research on All-Day Kindergarten). ERIC Digest.

    ERIC Educational Resources Information Center

    Clark, Patricia

    Noting that much of the early research on the effects of all-day kindergarten had serious problems with internal and external validity due to inadequate methodological standards, this Spanish-language digest reviews research conducted in the 1990s. The digest discusses the academic, social, and behavioral effects of all-day kindergarten, as well…

  20. Bibliografia sobre el "bilinguismo" del Paraguay (A Bibliography on Bilingualism in Paraguay)

    ERIC Educational Resources Information Center

    Melia, Bartomeu

    1974-01-01

    This bibliography of ninety-five entries ranging in publication date from 1847 to 1947 brings together information from areas of history, literature, sociology, anthropology, sociolinguistics, descriptive linguistics, folk-lore and language planning, the central criterion being the relationship of these areas specifically to the bilingual…

  1. Ahorre Energia: Consejos sobre el ahorro de dinero y energia en el hogar (Book)

    SciTech Connect

    Not Available

    2014-09-01

    Learn how to save money with Energy Saver: Tips on Saving Money & Energy at Home, from the U.S. Department of Energy. The Energy Saver guide will help you reduce your monthly energy costs and live more efficiently. This guide takes you through the systems and appliances that consume the most energy in your home, and provides solutions to cut costs for you while saving the environment. The Energy Saver guide also includes transportation tips to help you save money at the pump.

  2. Modelo analítico del efecto de PRS sobre satélites GPS

    NASA Astrophysics Data System (ADS)

    Meza, A.; Brunini, C.; Usandivaras, J. C.

    El sistema GPS (Global Position System) es, hoy en día, la herramienta de navegación y posicionamiento más potente y lo será sin duda en la próxima década. Gran parte de su valiosa utilidad se debe a la alta precisión que permite lograr y ésta, a su vez, depende, entre otras causas, de la precisión con que se conocen las órbitas de los satélites. La presión de radiación solar (PRS) fija el límite de la precisión con que pueden calcularse en la actualidad las efemérides satelitarias. El objetivo de este trabajo es proponer una mejor resolución de este fenómeno. El modelo analítico aquí presentado, se basa en el análisis del comportamiento de los residuos de un ajuste por mínimos cuadrados en el que se utiliza el modelo de PRS propuesto por Beutler. El mismo consiste en un modelo determinista del fenómeno con dos parámetros libres. Los resultados obtenidos ponen de manifiesto que, aún después de aplicar dichos parámetros, prevalecen en los residuos efectos semidiurnos en las componentes radial,tangencial y normal. Estos resultados obtenidos se comparan con los de un trabajo desarrollado por el Instituto de Berne (Beutler et al., 1994), en el que se utilizaron como pseudo-observaciones las órbitas precisas del IGS (CODE). El intervalo de integración escogido por este centro fueron las semanas 680 y 681. En resumen se tienen arcos de 14 días para todos los satélites, donde las efemérides precisas de los mismos para los 14 días fueron utilizados como pseudo-observaciones. El modelo de fuerza que empleó dicho centro fue básicamente el tradicional en lo que respecta al modelo de las fuerzas gravitacionales, y para la PRS utilizo el modelo standard de Beutler. Los parámetros de este modelo junto con las 6 condiciones iniciales (posición y velocidad) fueron ajustados por el método general de mínimos cuadrados. Los residuos en la componente radial, tangencial y normal, para los satélites con un buen comportamiento, presentan una componente semidiurna. El modelo analítico planteado en este trabajo, predice el comportamiento de los residuos que se observan en las publicaciones más recientes. Esto abre el camino para plantear una estimación distinta de las incógnitas del problema, basado en el método de colocación por mínimos cuadrados. Ello requiere modelar estadísticamente la señal debida a las componentes de la PRS que no son tomadas en cuenta en el modelo determinista.

  3. Reflexiones Sobre la Capacitacion de Docentes (Reflections on In-Service Teacher Training).

    ERIC Educational Resources Information Center

    Valle, Victor M.

    Everyone concerned with educational systems performance agrees that the improvement of teaching qualities is a high priority in any educational effort. Teachers are assigned the role of change agents and are presented with new challenges, e.g., to make education global and permanent, flexible enough to serve in any environment (in or out of the…

  4. Traumatic Brain Injury. Fact Sheet = Lesion Cerebral Traumatica (TBI). Hojas Informativas Sobre Discapacidades.

    ERIC Educational Resources Information Center

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This fact sheet, written in both English and Spanish, offers general information about traumatic brain injury. Information includes a definition, incidence, individual characteristics, and educational implications. The signs of traumatic brain injury are listed and include physical disabilities, difficulties with thinking, and social, behavioral,…

  5. Mental Retardation. Fact Sheet = El Retraso Mental. Hojas Informativas Sobre Discapacidades.

    ERIC Educational Resources Information Center

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This fact sheet on mental retardation is written in both English and Spanish. It begins with a vignette of a 15-year-old boy with mental retardation. Mental retardation is briefly explained as are some causes of mental retardation. It notes that a diagnosis of mental retardation looks at two things: first, the ability of a person's brain to learn,…

  6. Speech and Language Disorders. Fact Sheet = Trastornos del Habla y Lenguaje. Hojas Informativas Sobre Discapacidades.

    ERIC Educational Resources Information Center

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This fact sheet on speech and language disorders is presented in English and Spanish. It provides information on the definition of speech and language disorders and possible causes; the incidence (about one in ten people); and characteristics of delayed communication, speech disorders, and language disorders. It notes educational implications,…

  7. Sobre la ensenanza de la literatura hispanoamericana (The Teaching of Hispanoamerican Literature).

    ERIC Educational Resources Information Center

    Ellis, Keith

    There are three main problems in teaching Latin American literature: (1) It is difficult to maintain a regional overview, while, at the same time, including a sense of the literary history of Latin America; (2) It is necessary to teach literature so that the material seems worthwhile in its own right and not only as a complement to other…

  8. Profesionalismo: Un estudio fenomenologico sobre experiencias de universitarios en programas de salud

    NASA Astrophysics Data System (ADS)

    Lopez Ortiz, Wilma J.

    Some studies suggest that, upon admission, medicine programs students display eagerness for community service, aspirations to be useful, and to contribute to society's well-being. Those same studies reflect that qualities of idealism, moral nature, and internal motivation, suffer a subsequent diminishing. The researchers inferred that the main reason for this process of change in the mood and disposition of these future physicians lies in the modeling they receive from medical professionals throughout clinical learning activities, by way of behavior and relationships exhibited during daily interaction with peers, patients and the students themselves. This phenomenological study used a cross-sectional sample to explore the experiences of future health workers as they went through didactic and clinical phases of their training curriculum. The study employed semi-structured interviews and reflective journals to explore those experiences and to discover the meanings ascribed by the participants. The analysis revealed that the students defined "professionalism" in terms of scientific knowledge, commitment, respect for human dignity, comradeship, courtesy, empathy, integrity, altruism, motivation. They also described their feelings as they went through the didactic and clinical experiences, and recognized as very important the extracurricular activities of community service, describing them as useful opportunities which contributed to understand their work in terms of a mission dedicated to the achievement of the social benefit. From their individual perspectives, the clinical environment could, in general, be described as congruent with those characteristics of professionalism. During the study we had the opportunity to share, in a little deeper way, the environment... the world... of this small group of young students as we went on trying to decipher their feelings and thoughts. At the end, we realized the richness of their sensibilities, we perceived the intensity of their moral and ethical convictions, we were able to understand their concerns, worries, struggles and efforts. This life event had profound and significant repercussions in our personal and professional life. As a result, and from now on, we will no longer look at our young scholars and apprentices without imagining a noble spirit, with goals which at times could seem unattainable... without completely visualizing or conceiving real hope for a better country.

  9. Recursos de Trabajo: Informacion sobre Carreras (Occupational Resources: Career Information). CHOICE (Challenging Options in Career Education).

    ERIC Educational Resources Information Center

    Putnam and Northern Westchester Counties Board of Cooperative Educational Services, Yorktown Heights, NY.

    Part of a two-level career education curriculum initially developed for migrant children, the book is the first of three secondary level texts designed to provide high school students with self-awareness, job and role information, and decision-making/goal attaining information related to career education. The text provides job and role information…

  10. Como preparar un programa de informacion sobre la asistencia economica (Planning a Financial Aid Awareness Program).

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC.

    This booklet, written in Spanish, is intended to be used with a set of slides as part of a presentation to students on "How To Apply for Federal Student Aid" ("Como Solicitar la Asistencia Economica Federal para Estudiantes"). The first part of the book is a script based on the slides. After the script is a guide to hosting a financial aid…

  11. Simposio interamericano sobre administracion de la educacion (Inter-American Symposium on Educational Administration).

    ERIC Educational Resources Information Center

    Cespedes, Francisco S., Ed.

    The presidents and foreign ministers in Latin America recognize the importance of applying technology to school administration as the first step in any educational reform. In October 1968, the Organization of American States (OAS) [Organizacion de los Estados Americanos (OEA)], sponsored a symposium in Brasilia, Brazil, in cooperation with the…

  12. Cerebral Palsy. Fact Sheet = La Paralisis Cerebral. Hojas Informativas Sobre Discapacidades.

    ERIC Educational Resources Information Center

    National Information Center for Children and Youth with Disabilities, Washington, DC.

    This fact sheet on cerebral palsy is written in both English and Spanish. First, it provides a definition of cerebral palsy and considers various causes (e.g., an insufficient amount of oxygen reaching the fetal or newborn brain). The fact sheet then offers incidence figures and explains characteristics of the three main types of cerebral palsy:…

  13. Curso Introductorio sobre el Sistema DIALOG (Introductory Course on the DIALOG System).

    ERIC Educational Resources Information Center

    Rodriguez, Ketty

    As an introduction to the use of the DIALOG online retrieval service, this guide presents material that was developed during a fellowship at Carlos III University, School of Library Science and Documentation, Madrid (Spain) and that is based on a course on the same subject taught in English at Texas Women's University. Although the use of DIALOG…

  14. Cultural Diversity Awareness Inventory = Inventario Sobre el Reconocimiento de Diversas Culturas.

    ERIC Educational Resources Information Center

    Henry, Gertrude B.

    This booklet features a checklist designed to help persons who are involved in providing direct services to culturally diverse, young special needs children to assess their attitudes, beliefs, and behavior toward these children. The booklet also contains suggestions and lists of print, film, and filmstrip resources for developing a school program…

  15. Consideraciones sobre la Ansiedad en la Primera Infancia (Considerations Concerning Anxiety in Early Infancy).

    ERIC Educational Resources Information Center

    Muller, Elsa

    The results of an experience obtained while working with children in the early stages of infancy are presented. They are basically observations taken of a child's reaction to sudden changes, particularly separation from its mother. Anxiety was observed in these infants in diverse circumstances; in some cases it was at a normal level and in others…

  16. Questions Often Asked about Special Education Services = Preguntas sobre los servicios de educacion especial.

    ERIC Educational Resources Information Center

    Kupper, Lisa, Ed.

    This guide, available in both English and Spanish, answers questions often asked by parents about special education services. Questions and answers address the following topics: where to begin if a parent believes a child needs special education services, services available to very young children, the evaluation process, the Individualized…

  17. Preguntas y Respuestas sobre IDEA (Questions and Answers about the IDEA).

    ERIC Educational Resources Information Center

    Kupper, Lisa, Ed.

    1994-01-01

    This digest examines the mandates and requirements of the Individuals with Disabilities Education Act (IDEA). (Its scope does not include the IDEA's Part H program.) The digest gives a brief history of the IDEA, procedures for obtaining a copy of the IDEA and its regulations, and procedures for obtaining a copy of an individual state's special…

  18. Las Preguntas Que Hacen los Padres sobre la Escuela (Questions Parents Ask about School).

    ERIC Educational Resources Information Center

    National Opinion Research Center, Chicago, IL.

    This guide presents questions that parents frequently ask about their children's school along with answers to those questions. The questions and answers were prepared based on the results of studies conducted by the Partnership for Family Involvement in Education, the U.S. Department of Education, the GTE Foundation, and by the National Center for…

  19. Una Metodologia de Analisis de la Interaccion Alumno-Orgendaor en la Investigacion Sobre Informatica Educativa.

    ERIC Educational Resources Information Center

    Estepa, A.; And Others

    1992-01-01

    The recording of the interaction between pupil and computer is one of the data sources frequently used in research on the use of computers in teaching. Describes the analysis methodology of these recordings to determine the use of computers in statistics and its adaptation to other research work on the use of computers in education. (Author/MDH)

  20. Guia para los padres sobre educacion preescolar (A Parents' Guide to Early Childhood Education).

    ERIC Educational Resources Information Center

    Dodge, Diane Trister; Phinney, Joanna

    This handbook, entirely in Spanish, was originally intended for parents whose children attend programs which use "The Creative Curriculum for Early Childhood" (CCEC), but the information is also useful to parents whose children attend early childhood programs using other curriculum models based on child development theories. The purpose of the…

  1. Comunicado de prensa del Informe Anual sobre el Estado del Cáncer 2015

    Cancer.gov

    Por primera vez, los investigadores han usado datos a nivel nacional para determinar la incidencia de los cuatro subtipos moleculares principales de cáncer de seno (mama) por edad, raza y grupo étnico, nivel de pobreza y varios otros factores. El informe

  2. Notas sobre los Sonidos Consonantes en Espanol (Notes on Consonant Sounds in Spanish)

    ERIC Educational Resources Information Center

    Ezquerra, Raimundo

    1974-01-01

    This paper examines the Spanish phonetic system, as set forth by Navarro Tomas in his "Manual de Pronunciacion Espanola," and discusses the influences exerted by certain sounds over others. (Text is in Spanish.) (CK)

  3. Trabajos de fotometría de moderada precisión, sobre el cometa Halley.

    NASA Astrophysics Data System (ADS)

    Parachú, O. A.

    Experimental data to determine the visual magnitude of Comet Halley's head are presented. Two different ways are chosen; one using the photographical contours method and other one determining the visibility beginning time at evening twilight or the visibility extinction time at morning twilight.

  4. Consideracoes Historicas sobre o Ensino Profissionalizante no Brasil (Historical Considerations about Professional Education in Brazil).

    ERIC Educational Resources Information Center

    Barros, Marta Silene Ferreira

    2000-01-01

    Analyzes the paths taken in professional education in Brazil from the colonial period until the formation of the republic. Refers to specialists as well as specific laws for each period described in the study. (BT)

  5. Iniciativa sobre Efectividad: Un entorno para el aprendizaje (Initiative about Effectiveness: An Environment for Learning).

    ERIC Educational Resources Information Center

    Moreno Garcia, Teresa, Ed.

    2000-01-01

    This Spanish- and Portuguese-language bulletin presents articles focusing on the Effectiveness Initiative (EI), a project of the Bernard van Leer Foundation for making a qualitative analysis of those elements of the programs of Early Childhood Development (ECD) that benefit the participants and their communities and cultures. The first article…

  6. Perspectiva sobre una Personalidad Senera: Carmen Fischer Ramirez (Perspective on a Singular Personality: Carmen Fischer Ramirez).

    ERIC Educational Resources Information Center

    Quezeda, Dina Alarcon

    1992-01-01

    Traces the career of Carmen Fischer Ramirez, focusing on her work in improving early childhood education in Chile. Reviews her university career, work with the World Organization for Early Childhood Education, and major publications. (AC)

  7. Content and persistence of extracellular DNA in native soils

    NASA Astrophysics Data System (ADS)

    Blagodatskaya, Evgenia; Blagodatsky, Sergey; Anderson, Traute-Heidi; Kuzyakov, Yakov

    2014-05-01

    The long-term persistence of soil extracellular DNA is questionable because of high potential activity of nucleases produced by soil microorganisms. By the other hand, the relative persistence of DNA-like biopolymers could be due to their adsorption on clay minerals and humus substances in soil. High-specific and ultra sensitive reagent PicoGreenTM (Molecular Probes) permits the quantitative assessment of microbial dsDNA in diluted soil extracts giving a good tool for tracing the DNA fate in soil. Our goal was to determine intracellular and extracellular DNA content in cambisol (loamy sand) and in chernozem (silty loam) soils and to investigate the possible adsorption and degradation of extracellular DNA in soil. Optimized procedure of mechanical and enzymatic destruction of cell walls was used for direct extraction of microbial DNA with Tris-EDTA buffer (Blagodatskaya et al., 2003). Extracellular dsDNA was determined in distilled water and in Tris-EDTA extracts without enzymatic or mechanical treatments. DNA content was determined after addition of PicoGreen to diluted soil extracts. Degradation of extracellular DNA was traced during 24 h incubation of 2 µg lambda-phage DNA in soil. Possible DNA adsorption to soil matrix was determined by recovery of lambda -phage DNA added to autoclaved soil. Extracellular dsDNA was absent in water extracts of both soils. The content of extracellular dsDNA extracted by Tris-EDTA buffer was 0.46 µg/g in chernozem and 1.59 µg/g in cambisol amounting 0.43 and 2.8% of total dsDNA content in these soils, respectively. 100% and 64.8% of added extracellular lambda -phage dsDNA was found in cambisol and chernozem soils, respectively, in 5 h after application. 39% and 73.5% of added DNA disappeared in cambisol and in chernozem, respectively, during 24 h incubation. Degradation rate of extracellular DNA depended on microbial biomass content, which was 2.5 times higher in chernozem as compared to cambisol. Maximum adsorption of DNA by

  8. Cadmium content of plants as affected by soil cadmium concentration

    SciTech Connect

    Lehoczky, E.; Szabados, I.; Marth, P.

    1996-12-31

    Pot experiments were conducted in greenhouse conditions to study the effects of increasing cadmium (Cd) levels on biomass production and Cd contents in corn, (Zea mays L.), garlic (Allium sativum L.), and spinach (Spinacia oleracea L.). Plants were grown in two soil types: Eutric cambisol soil and A gleyic luvisol soil. Spinach proved to be the most sensitive to Cd treatments as its biomass considerably decreased with the increasing Cd levels. Cadmium contents of the three crops increased with increasing levels of Cd applications. Statistical differences were observed in the Cd contents of crops depending on soil type. With the same Cd rates, Cd tissue concentration of test plants grown in the strongly acidic Gleyic luvisol soil were many times higher than that of plants grown in a neutral Eutric cambisol soil. 14 refs., 4 tabs.

  9. Sorption and desorption of sulfentrazone in Brazilian soils.

    PubMed

    Passos, Ana Beatriz R J; Freitas, Marco Antonio M; Torres, Lívia G; Silva, Antonio A; Queiroz, Maria Eliana L R; Lima, Cláudio F

    2013-01-01

    This study was undertaken to obtain information about the behavior of sulfentrazone in soil by evaluating the sorption and desorption of the herbicide in different Brazilian soils. Batch equilibrium method was used and the samples were analyzed by high performance liquid chromatography. Based on the results obtained from the values of Freundlich constants (Kf), we determined the order of sorption (Haplic Planosol < Red-Yellow Latosol < Red Argisol < Humic Cambisol < Regolitic Neosol) and desorption (Regolitic Neosol < Red Argisol < Humic Cambisol < Haplic Planosol < Red-Yellow Latosol) of sulfentrazone in the soils. The process of pesticide sorption in soils was dependent on the levels of organic matter and clay, while desorption was influenced by the organic matter content and soil pH. Thus, the use of sulfentrazone in soils with low clay content and organic matter (low sorption) increases the probability of contaminating future crops. PMID:23638891

  10. Influence of soil tillage and erosion on the dispersion of glyphosate and aminomethylphosphonic acid in agricultural soils

    NASA Astrophysics Data System (ADS)

    Todorovic, Gorana Rampazzo; Rampazzo, Nicola; Mentler, Axel; Blum, Winfried E. H.; Eder, Alexander; Strauss, Peter

    2014-03-01

    Erosion processes can strongly influence the dissipation of glyphosate and aminomethylphosphonic acid applied with Roundup Max® in agricultural soils; in addition, the soil structure state shortly before erosive precipitations fall can be a key parameter for the distribution of glyphosate and its metabolite. Field rain simulation experiments showed that severe erosion processes immediately after application of Roundup Max® can lead to serious unexpected glyphosate loss even in soils with a high presumed adsorption like the Cambisols, if their structure is unfavourable. In one of the no-tillage-plot of the Cambisol, up to 47% of the applied glyphosate amount was dissipated with surface run-off. Moreover, at the Chernozem site with high erosion risk and lower adsorption potential, glyphosate could be found in collected percolation water transported far outside the 2x2 m experimental plots. Traces of glyphosate were found also outside the treated agricultural fields.

  11. Estudio de la influencia de la refrigeracion con aire de forma natural e inducida en el comportamiento de instalaciones fotovoltaicas

    NASA Astrophysics Data System (ADS)

    Mazon Hernandez, Rocio

    panels are analysed to compare and select the best configuration. The presented research provides a deep knowledge of how they work as well as information and results for an improvement in future designs of building integrated photovoltaic systems. Este estudio se centra en analizar la influencia negativa de la temperatura en la produccion electrica de paneles fotovoltaicos al estar emplazados sobre cubierta de acero, como sucede en naves industriales y sobre un invernadero. Se estudian diferentes configuraciones que permitan refrigerar los paneles, reduciendo su temperatura y mejorar su rendimiento. Para abordar este problema, se han construido dos instalaciones experimentales, fieles a plantas solares en funcionamiento. Una instalacion engloba dos paneles fotovoltaicos sobre estructura fija al suelo. Uno de los paneles esta integrado sobre una superficie paralela y metalica. Entre ambas superficies existe un espacio que posibilita circular aire, permitiendo refrigerar el panel por conveccion natural, o conveccion forzada impulsando el aire con un ventilador. El otro panel, libre por su cara posterior y se ha considerado de referencia. Se ha estudiado el comportamiento del panel integrado sobre cubierta para diferentes secciones de aire y velocidades inducidas, comparandolo con el panel de referencia. Se ha desarrollado un modelo experimental que nos permite determinar la temperatura del panel en funcion de las variables que influyen en su refrigeracion. Adicionalmente, se han analizado los datos de una planta solar en funcionamiento, con paneles de igual caracteristicas, obteniendo correlaciones entre la temperatura del panel y las variables electricas y comparandolos con las obtenidas en la instalacion experimental. La segunda instalacion experimental reproduce parte de una instalacion solar sobre un invernadero, formada por cuatro paneles fotovoltaicos colocados sobre el plastico del invernadero, existiendo un canal divergente entre ambas superficies. Se estudia la

  12. CO2 Production by Soils of Lazovskiy Reserve, South-East Primorye

    NASA Astrophysics Data System (ADS)

    Semal, Viktoriia; Purtova, Lyudmila; Kostenkov, Nikolay; Nesterova, Olga; Tregubova, Valentina; Derbentseva, Alla; Tyurina, Elena; Kravchenko, Alla; Glotova, Elena; Sergeeva, Olesya; Korshenko, Ekaterina

    2016-04-01

    CO2 is practically the only volatile compound in automorphic soils, in the form of which carbon is lost. So the investigation of the carbon dioxide production rate dynamics makes it possible not only to judge the biological processes intensity but also to estimate the organic substance losses due to mineralization. Lazovskiy Reserve holds a unique geographic location: its territory occupies both biologically rich coastal marine area and continental part of Sikhote Alin south-east branches, including both typical mountainous areas and wide intermountain river valleys. Specific conditions of the organic substance formation and transformation, its seasonal dynamics are due not only to the features of the monsoon climate but also to the availability of unique primeval coniferous broadleaved liana forests in the central part of the Reserve and coastal post-fire successions of the secondary oak forests. CO2 emission was observed in the laboratory setting (ex. situ), at 100% maximum water holding capacity (MWHC) and at 60% MWHC. It was found that the CO2 production extensive indicators are typical for Cambisol containing high level of humus. CO2 mean values at 60% MWHC ranged into a following series: Mollic Cambisol - Cambic Fluvisol - Dystric Cambisol.

  13. Changes in cadmium mobility during composting and after soil application

    SciTech Connect

    Hanc, Ales Tlustos, Pavel; Szakova, Jirina; Habart, Jan

    2009-08-15

    The effect of twelve weeks of composting on the mobility and bioavailability of cadmium in six composts containing sewage sludge, wood chips and grass was studied, along with the cadmium immobilization capacity of compost. Two different soils were used and Cd accumulation measured in above-ground oat biomass (Avena sativa L.). Increasing pH appears to be an important cause of the observed decreases in available cadmium through the composting process. A pot experiment was performed with two different amounts of compost (9.6 and 28.8 g per kg of soil) added into Fluvisol with total Cd 0.255 mg kg{sup -1}, and contaminated Cambisol with total Cd 6.16 mg kg{sup -1}. Decrease of extractable Cd (0.01 mol l{sup -1} CaCl{sub 2}) was found in both soils after compost application. The higher amount of compost immobilized an exchangeable portion of Cd (0.11 mol l{sup -1} CH{sub 3}COOH extractable) in contaminated Cambisol unlike in light Fluvisol. The addition of a low amount of compost decreased the content of Cd in associated above-ground oat biomass grown in both soils, while a high amount of compost decreased the Cd content in oats only in the Cambisol.

  14. What has happened in about the last 20 years in the Canyoles watershed?

    NASA Astrophysics Data System (ADS)

    Ángel González Peñaloza, Félix; Cerdà, Artemi; Díaz del Olmo, Fernando

    2013-04-01

    Union FP7. ENV.2009 243857. Keywords: GIS, land use, degradation, Cànyoles valley, agricultural practices. References Bodí, M.B., Cerdà, A., Mataix-Solera, J., Doerr, S.H. 2012. Efectos de los incendios forestales en la vegetación y el suelo en la cuenca mediterránea: revisión bibliográfica. Boletín de la Asociación de Geógrafos Españoles 58, 33-35 Cerdà, A, Giménez - Morera, A. Terol, E., Domínguez, A. Jurgensen, M.F., Doerr, S.H. 1999. Cultivos de cítricos y erosión de suelos en el este de la Península Ibérica. En Control de la Degradación de los suelos y cambio global (Eds: Sánchez Díaz, J., Asins Velis, S.). IV Simposio sobre control de la degradación de los suelos y cambio global. Universitat de València. Valencia. 71 - 72. Cerdà, A. 1994. Arroyada superficial en terrazas de cultivo abandonadas. El caso del País Valenciano. Cuadernos de Geografía 56, 135-154 Cerdá, A. 2007. Soil water erosion on road embankments in Eastern Spain. Science of the Total Environments 378, 151-155. González-Peñaloza, F.A., Cerdà, Zavala, L.M., Jordán, A. 2012. Do conservative agriculture practices increase soil water repellency? A case study in citrus-cropped soils. Soil & Tillage Research 124, 233 - 239. Keenleyside, C., Tucker, G.M. 2010. Farmland Abandonment in the EU: An assessment of Trend and Prospects. Report Prepared for WWF. Institute for European Environmental Policy, London. 93 pp. MacDonald, D., Crabtree, J.R., Wiesinger, G., Dax, T., Stamou, N., Fleury, P., Gutiérrez-Lazpita, J., Gibon, A. 2000. Agricultural abandonment in mountain areas of Europe: Environmental consequenses and policy reponse. Journal of Environmental Management 59, 47-69. Piqueras, J. 2012. Geografía del Territorio Valenciano. Departament de Geografia, Universitat de València (Valencia, España). 256 pp. Renwick, A., Jansson, T., Verburg, P.H., Revoredo-Giha, C., Britz, W., Gocht, A., McCracken, D. 2013. Policy reforms and agricultural land abandonment in the EU. Land Use

  15. Impact of vegetation types on soil organic carbon stocks SOC-S in Mediterranean natural areas

    NASA Astrophysics Data System (ADS)

    Parras-Alcántara, Luis; Lozano-García, Beatriz; Cantudo-Pérez, Marta

    2015-04-01

    with different vegetation types (Quercus suber, Quercus ilex, Quercus faginea, Pinus pinaster and Pinus pinea) in The Cardeña-Montoro Natural Park, a nature reserve that consists of a 38,449 ha forested area in southern Spain. Sixty-eight sampling points were selected in the study zone. Each sampling point was analyzed as soil control section with different depth increments (0-25, 25-50, 50-75 and 75-100 cm). The studied soils were classified as Cambisols and the major goal of this research was to study the SOCS variability at regional scale. The total SOCS in The Cardeña-Montoro Natural Park was higher in MEOW with olive grove (111,69 Mg ha-1) and lower in MEOW with Quercus faginea (93,57 Mg ha-1). However, when the top soil (superficial section control) was analyzed, the SOCS was the highest in MEOW with olive grove (70,12 Mg-1) and the lowest in MEOW with Pinus (47,82 Mg ha-1). This research is a preliminary assessment for modeling SOCS at the regional level in Mediterranean natural areas. References Hontoria, C., Rodríguez-Murillo, J., and Saa, A.: Contenido de carbono orgánico en el suelo y factores de control en la España Peninsular, Edafología, 11, 149-155, 2004. Parras-Alcántara, L., Díaz-Jaimes, L., and Lozano-García, B: Organic farming affects C and N in soils under olive groves in Mediterranean areas, Land Degrad. Develop., in press, available online: in Wiley Online Library (wileyonlinelibrary.com), http://dx.doi.org/10.1002/ldr.2231, 2013. Parras-Alcántara, L., Díaz-Jaimes, L., Lozano-García, B., Fernández Rebollo, P., Moreno Elcure, F., Carbonero Muñoz, M.D.: Organic farming has little effect on carbon stock in a Mediterranean dehesa (southern Spain). Catena 113 (2014) 9-17. http://dx.doi.org/10.1016/j.catena.2013.09.002 Parras-Alcántara, L., Díaz-Jaimes, L., and Lozano-García, B.: Management effects on soil organic carbon stock in Mediterranean open rangelands -- treeless grasslands, Land Degrad. Develop., in press, available online: in

  16. Efecto de la dieta artificial MP sobre la emergencia y relacion de sexos de Phymastichus coffea (Hymenoptera:Eulophidae) mantenido sobre su hueped, Hypothenemus hampei (Coleoptera: Scloytidae)a traves de generaciones contin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phymastichus coffea La Salle (Hymenoptera: Eulophidae) is an endoparasitoid that attacks the adult coffee berry borer, Hypothenemus hampei Ferrari (Coleoptera: Scolytidae). The MP diet developed by Portilla and Streett is the only reported diet that allows cultures of P. coffea to develop and repr...

  17. Análise sobre o Conhecimento de um Grupo de Alunos do Ensino Médio da Rede Estadual de São Paulo sobre Termos e Fenômenos Astronômicos do Cotidiano

    NASA Astrophysics Data System (ADS)

    de Oliveira, E. F.; Voelzke, M. R.; Amaral, L. H.

    2007-08-01

    Embora os Parâmetros Curriculares Nacionais do Ensino Médio (PCN-EM) e as orientações complementares a esses Parâmetros (PCN+) apontem a importância de uma abordagem significativa de conceitos relacionados à astronomia nas aulas de Física, muitos estudantes terminam o Ensino Médio (EM) sem compreender a razão de certos acontecimentos de origem celeste, ainda que estes façam parte de seu cotidiano. Este trabalho tem por objetivo analisar os conhecimentos básicos em astronomia dos alunos de EM da escola estadual Batista Renzi, bem como investigar os meios através dos quais estes conhecimentos foram adquiridos. Para tanto foi elaborado um questionário de múltipla escolha aplicado a 310 alunos distribuídos entre as três séries do EM dos períodos matutino e noturno. Dessa forma, observou-se que apenas 34,5% relacionaram as estações do ano à inclinação do eixo de rotação da Terra, 21,3% indicaram a influência gravitacional da Lua e do Sol como responsáveis pelo fenômeno das marés, 24,5% indicaram corretamente quais são os objetos celestes mais próximos da Terra, 36,1% identificaram ano-luz como uma medida de distância e 34,2% reconheceram uma estrela cadente como meteoro. Em contrapartida, 67,1% compreendiam a sucessão entre dia e noite, 73,9% identificaram o Sol como estrela e 52,3% relacionaram o Big Bang à origem do Universo. Além disso, foram comparadas as respostas de alunos de diferentes séries e períodos, observando-se, dentre outras coisas, que os estudantes do terceiro ano apresentam um percentual de acertos semelhante ao dos alunos do primeiro, caracterizando que a abordagem de tópicos relacionados à astronomia no EM não tem contribuído para uma maior compreensão dos fenômenos e conceitos.

  18. Sobre as inclinações carnais: inflexões do pensamento cristão sobre os desejos e as sensações prazerosas do baixo corporali

    PubMed Central

    RIOS, LUÍS FELIPE; PARKER, RICHARD; TERTO, VERIANO

    2011-01-01

    On carnal inclinations: from early Christianity to the present This study develops a historical review of the meanings of the “flesh” in the West, focusing on its significance in the context of Christianity. Our hope is that a study along these lines can help to illuminate current understandings of questions related to sexuality both within and outside of the religious contexts found in contemporary Brazil. Such questions are of special interest for those who are concerned with both old and new problems found in the field that has come to be known as sexual and reproductive rights, with implications for the field of Public Health. PMID:21980215

  19. Validacion de un Inventario Sobre La Percepcion de Los Padres de Superdotados Respecto a Los Servicios Educativos Disponibles Para Estos

    ERIC Educational Resources Information Center

    Medina Munoz, Arlette Zamarie

    2013-01-01

    In Puerto Rico, there isn't a survey that collects the parent's perception of the available services for gifted children. Considering this, in this investigation an instrument was created and scientifically validated to collect the parents' perception of the educational services available. The instrument was validated using internal…

  20. El Conocimiento Ocupacional y del Yo para los Grupos Especiales. Monografias sobre el Conocimiento Ocupacional y del Yo.

    ERIC Educational Resources Information Center

    Hoyt, Kenneth B.

    This Spanish translation of ED 132 428 includes the three papers representing Office of Education attempts to face the need for improving delivery of career education to special portions of the population. New additions are brief sections on basic definitions and additional considerations of the significance of work. The first paper, on career…

  1. Una Guia de Consejos Practicos Sobre la Lectura para los Padres (A Guide to Reading Tips for Parents).

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC.

    The No Child Left Behind program changes the federal role in education by asking America's schools to describe their success in terms of what each student accomplishes. The information in this reading guide, presented in Spanish, was developed by the United States Department of Education to assist parents, caregivers, and teachers in understanding…

  2. "O Que Diriam Sobre Os Portugueses?????" [What Would You Say about Portuguese People?]: Intercultural Curiosity in Multilingual Chat-Rooms

    ERIC Educational Resources Information Center

    Araujo e Sa, Maria Helena; de Carlo, Maddalena; Melo-Pfeifer, Silvia

    2010-01-01

    In this study, we intend to discuss questioning as a sign of Intercultural Communicative Competence in plurilingual environments, stressing the relationship between questioning and the process of developing discovery skills in Romance chat-rooms. Focusing specifically on episodes beginning with intercultural questioning, we will analyse: (1)…

  3. Mobile Library Guidelines. IFLA Professional Report No. 28 [and] Lineamientos sobre Bibliotecas Moviles. Informes Professionales de IFLA: 30.

    ERIC Educational Resources Information Center

    Pestell, Robert

    This publication provides the latest information available on the equipment and operation of mobile libraries operating out of road vehicles. The guide provides details on the establishment of mobile library services, financing, vehicles, furniture and equipment, staffing, collections, service base, and publicity. Some generalizations with regard…

  4. General Information about Learning Disabilities (Fact Sheet Number 7) = Informacion General sobre Impedimentos en el Aprendizaje (Fact Sheet Number 19).

    ERIC Educational Resources Information Center

    Interstate Research Associates, Inc., Washington, DC.

    This fact sheet providing general information about learning disabilities is presented in both English and Spanish versions. It begins with the federal definition of learning disabilities and a discussion of its implications followed by estimates of incidence. Typical characteristics of students with learning disabilities are then summarized as…

  5. Lengua Viva: Un programa de television sobre el habla espontanea (Living Language: A Television Program on Spontaneous Speech)

    ERIC Educational Resources Information Center

    Criado de Val, Manuel

    1975-01-01

    A program shown on Spanish television is a linguistic survey of Spain. Spontaneous conversations were filmed and taped in all regions of the country. It is evident that the mass media are spreading a standard form of speech and that regional differences are becoming blurred. (Text is in Spanish.) (CHK)

  6. Personal Safety for Children: A Guide for Parents = Una guia para los padres sobre la seguridad personal de los ninos.

    ERIC Educational Resources Information Center

    Department of Justice, Washington, DC.

    Noting that parents and teachers have the responsibility of safeguarding children and teaching them the skills they need to be safe, this pamphlet, in Spanish and English versions, is designed to help parents talk to their children about how to protect themselves against abduction and exploitation. The pamphlet is organized into six sections.…

  7. Estudio numerico y experimental del proceso de soldeo MIG sobre la aleacion 6063--T5 utilizando el metodo de Taguchi

    NASA Astrophysics Data System (ADS)

    Meseguer Valdenebro, Jose Luis

    Electric arc welding processes represent one of the most used techniques on manufacturing processes of mechanical components in modern industry. The electric arc welding processes have been adapted to current needs, becoming a flexible and versatile way to manufacture. Numerical results in the welding process are validated experimentally. The main numerical methods most commonly used today are three: finite difference method, finite element method and finite volume method. The most widely used numerical method for the modeling of welded joints is the finite element method because it is well adapted to the geometric and boundary conditions in addition to the fact that there is a variety of commercial programs which use the finite element method as a calculation basis. The content of this thesis shows an experimental study of a welded joint conducted by means of the MIG welding process of aluminum alloy 6063-T5. The numerical process is validated experimentally by applying the method of finite element through the calculation program ANSYS. The experimental results in this paper are the cooling curves, the critical cooling time t4/3, the weld bead geometry, the microhardness obtained in the welded joint, and the metal heat affected zone base, process dilution, critical areas intersected between the cooling curves and the curve TTP. The numerical results obtained in this thesis are: the thermal cycle curves, which represent both the heating to maximum temperature and subsequent cooling. The critical cooling time t4/3 and thermal efficiency of the process are calculated and the bead geometry obtained experimentally is represented. The heat affected zone is obtained by differentiating the zones that are found at different temperatures, the critical areas intersected between the cooling curves and the TTP curve. In order to conclude this doctoral thesis, an optimization has been conducted by means of the Taguchi method for welding parameters in order to obtain an improvement on mechanical properties in aluminum metal joint. Los procesos de soldadura por arco electrico representan unas de las tecnicas mas utilizadas en los procesos de fabricacion de componentes mecanicos en la industria moderna. Los procesos de soldeo por arco se han adaptado a las necesidades actuales, haciendose un modo de fabricacion flexible y versatil. Los resultados obtenidos numericamente en el proceso de soldadura son validados experimentalmente. Los principales metodos numericos mas empleados en la actualidad son tres, metodo por diferencias finitas, metodos por elementos finitos y metodo por volumenes finitos. El metodo numerico mas empleado para el modelado de uniones soldadas, es el metodo por elementos finitos, debido a que presenta una buena adaptacion a las condiciones geometricas y de contorno ademas de que existe una diversidad de programas comerciales que utilizan el metodo por elementos finitos como base de calculo. Este trabajo de investigacion presenta un estudio experimental de una union soldada mediante el proceso MIG de la aleacion de aluminio 6063-T5. El metodo numerico se valida experimentalmente aplicando el metodo de los elementos finitos con el programa de calculo ANSYS. Los resultados experimentales obtenidos son: las curvas de enfriamiento, el tiempo critico de enfriamiento t4/3, geometria del cordon, microdurezas obtenidas en la union soldada, zona afectada termicamente y metal base, dilucion del proceso, areas criticas intersecadas entre las curvas de enfriamiento y la curva TTP. Los resultados numericos son: las curvas del ciclo termico, que representan tanto el calentamiento hasta alcanzar la temperatura maxima y un posterior enfriamiento. Se calculan el tiempo critico de enfriamiento t4/3, el rendimiento termico y se representa la geometria del cordon obtenida experimentalmente. La zona afectada termicamente se obtiene diferenciando las zonas que se encuentran a diferentes temperaturas, las areas criticas intersecadas entre las curvas de enfriamiento y la curva TTP. Para finalizar el trabajo de investigacion se ha realizado un

  8. Lecturas sobre educacion de adultos en America latina (Readings on Adult Education in Latin America). Serie: Retablo de Papel 14.

    ERIC Educational Resources Information Center

    Latapi, Pablo, Comp.; Castillo, Alfonso, Comp.

    Twelve essays written in Spanish on the state of adult education in Latin America are presented. The essays are organized into three main sections, including: "Concepto y evolucion historica de la educacion de adultos" (Conception and Historical Evolution of Adult Education); "Aspectos particulares" (Specific Subjects); and "Tendencias y…

  9. Apuntes sobre la distribución geográfica de Neoleucinodes elegantalis (Lepidoptera: Crambidae) en Colombia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Neoleucinodes elegantalis is considered the most limiting pest for production and merchandising of solanaceous fruit and vegetables in the Neotropics. The present study updates the geographic distribution of N. elegantalis in areas of major agricultural production of Solanum lycopersicum, S. melong...

  10. Investigación del USGS sobre el ecosistema de arrecifes de coral en el Atlántico

    USGS Publications Warehouse

    Kuffner, Ilsa B.; Yates, Kimberly K.; Zawada, David G.; Richey, Julie N.; Kellogg, Christina A.; Toth, Lauren T.; Torres-Garcia, Legna M.

    2015-01-01

    Los arrecifes de coral son estructuras sólidas, biomineralizadas que protegen comunidades costeras actuando como barreras protectoras de peligros tales como los huracanes y los tsunamis. Estos proveen arena a las playas a través de procesos naturales de erosión, fomentan la industria del turismo, las actividades recreacionales y proveen hábitats pesqueros esenciales. La conti-nua degradación mundial de ecosistemas de arrecifes de coral está bien documentada. Existe la necesidad de enfoque y organización de la ciencia para entender los procesos complejos físicos y biológicos e interacciones que están afectando el estado de los arrecifes coralinos y su capacidad para responder a un entorno cambiante.

  11. DISYUNTIVAS EN LAS CONCEPCIONES SOBRE AUTONOMÍA Y BENEFICENCIA QUE AFECTAN LA TERAPÉUTICA DEL INTENTO SUICIDA1

    PubMed Central

    Mondragón, Liliana; Monroy, Zuraya; Ito, Ma. Emily; Medina-Mora, Dra. Ma. Elena

    2010-01-01

    El objetivo del trabajo es conocer las disyuntivas entre los principios de beneficencia y autonomía, que se presentan en la relación médico-paciente, durante la terapéutica del intento de suicidio. La investigación se realizó en dos hospitales psiquiátricos de la Ciudad de México. La muestra incluyó a tres sujetos con intento de suicidio, mayores de 18 años, que eran atendidos en consulta externa a causa de una lesión autoinfligida en el último año, y a tres psiquiatras que trataban a estos pacientes. La información se obtuvo previo consentimiento informado en entrevistas individuales. Se llevó a cabo un análisis de discurso argumentado para encontrar los significados que los participantes otorgaron a los principios bioéticos y las posibles disyuntivas entre éstos. Las discordancias entre la beneficencia y la autonomía estuvieron relacionadas con el beneficio del tratamiento, el respeto por los valores y las creencias de los pacientes, entre otros. Este trabajo presenta consideraciones éticas relevantes en el escenario clínico, al ofrecer al psiquiatra un análisis bioético que le permita actuar de acuerdo con la beneficencia y respetando la autonomía del paciente frente a casos de intento de suicidio y, de esta forma procurar una mejor atención para ellos. PMID:20830214

  12. Estudio numerico y experimental del proceso de soldeo MIG sobre la aleacion 6063--T5 utilizando el metodo de Taguchi

    NASA Astrophysics Data System (ADS)

    Meseguer Valdenebro, Jose Luis

    Electric arc welding processes represent one of the most used techniques on manufacturing processes of mechanical components in modern industry. The electric arc welding processes have been adapted to current needs, becoming a flexible and versatile way to manufacture. Numerical results in the welding process are validated experimentally. The main numerical methods most commonly used today are three: finite difference method, finite element method and finite volume method. The most widely used numerical method for the modeling of welded joints is the finite element method because it is well adapted to the geometric and boundary conditions in addition to the fact that there is a variety of commercial programs which use the finite element method as a calculation basis. The content of this thesis shows an experimental study of a welded joint conducted by means of the MIG welding process of aluminum alloy 6063-T5. The numerical process is validated experimentally by applying the method of finite element through the calculation program ANSYS. The experimental results in this paper are the cooling curves, the critical cooling time t4/3, the weld bead geometry, the microhardness obtained in the welded joint, and the metal heat affected zone base, process dilution, critical areas intersected between the cooling curves and the curve TTP. The numerical results obtained in this thesis are: the thermal cycle curves, which represent both the heating to maximum temperature and subsequent cooling. The critical cooling time t4/3 and thermal efficiency of the process are calculated and the bead geometry obtained experimentally is represented. The heat affected zone is obtained by differentiating the zones that are found at different temperatures, the critical areas intersected between the cooling curves and the TTP curve. In order to conclude this doctoral thesis, an optimization has been conducted by means of the Taguchi method for welding parameters in order to obtain an improvement on mechanical properties in aluminum metal joint. Los procesos de soldadura por arco electrico representan unas de las tecnicas mas utilizadas en los procesos de fabricacion de componentes mecanicos en la industria moderna. Los procesos de soldeo por arco se han adaptado a las necesidades actuales, haciendose un modo de fabricacion flexible y versatil. Los resultados obtenidos numericamente en el proceso de soldadura son validados experimentalmente. Los principales metodos numericos mas empleados en la actualidad son tres, metodo por diferencias finitas, metodos por elementos finitos y metodo por volumenes finitos. El metodo numerico mas empleado para el modelado de uniones soldadas, es el metodo por elementos finitos, debido a que presenta una buena adaptacion a las condiciones geometricas y de contorno ademas de que existe una diversidad de programas comerciales que utilizan el metodo por elementos finitos como base de calculo. Este trabajo de investigacion presenta un estudio experimental de una union soldada mediante el proceso MIG de la aleacion de aluminio 6063-T5. El metodo numerico se valida experimentalmente aplicando el metodo de los elementos finitos con el programa de calculo ANSYS. Los resultados experimentales obtenidos son: las curvas de enfriamiento, el tiempo critico de enfriamiento t4/3, geometria del cordon, microdurezas obtenidas en la union soldada, zona afectada termicamente y metal base, dilucion del proceso, areas criticas intersecadas entre las curvas de enfriamiento y la curva TTP. Los resultados numericos son: las curvas del ciclo termico, que representan tanto el calentamiento hasta alcanzar la temperatura maxima y un posterior enfriamiento. Se calculan el tiempo critico de enfriamiento t4/3, el rendimiento termico y se representa la geometria del cordon obtenida experimentalmente. La zona afectada termicamente se obtiene diferenciando las zonas que se encuentran a diferentes temperaturas, las areas criticas intersecadas entre las curvas de enfriamiento y la curva TTP. Para finalizar el trabajo de investigacion se ha realizado una optimizacion, con la aplicacion del metodo de Taguchi, de los parametros de soldeo con el objetivo de obtener una mejora sustancial en las propiedades mecanicas de las uniones metalicas de aluminio.

  13. The ABCs of Special Education: A Handbook for Parents = El ABS Sobre Educacion Especial: Un Folleto para los Padres.

    ERIC Educational Resources Information Center

    Ewing, Preston E., Jr.; Hinton, Valeska S.

    This bilingual handbook is intended to help parents understand their rights under P.L. 94-142, the Education for All Handicapped Children Act. The following topics are addressed: the Act's legislative history, identification of special education, explanation of P.L. 94-142, parents' rights to know, student records, student testing, students'…

  14. Informe Anual a la Nación sobre el Cáncer de 1975 a 2008: preguntas y respuestas

    Cancer.gov

    Los índices generales de mortalidad por cáncer han seguido disminuyendo desde principios de los noventa entre hombres, mujeres y niños. Los índices de mortalidad disminuyeron en promedio 1,6% por año entre 2004 y 2008.

  15. Ecocardiografía tridimensional. Nuevas perspectivas sobre la caracterización de la válvula mitral

    PubMed Central

    Solis, Jorge; Sitges, Marta; Levine, Robert A.; Hung, Judy

    2010-01-01

    Recent developments in three-dimensional echocardiography have made it possible to obtain images in real time, without the need for off-line reconstruction. These developments have enabled the technique to become an important tool for both research and daily clinical practice. A substantial proportion of the studies carried out using three-dimensional echocardiography have focused on the mitral valve, the pathophysiology of mitral valve disease and, in particular, functional mitral regurgitation. The aims of this article were to review the contribution of three-dimensional echocardiography to understanding of the functional anatomy of the mitral valve and to summarize the resulting clinical applications and therapeutic implications. PMID:19232192

  16. Liv and Lucky in Liverland. . . Color Us Healthy! A Workbook about Your Liver = Un Cuaderno de trabajo sobre tu higado.

    ERIC Educational Resources Information Center

    1995

    This workbook/coloring book, on the liver and good health is designed for primary school students. The 21 line drawings illustrate different aspects of liver function, maintaining a healthy liver, and preventing liver disease. Each page is captioned in both English and Spanish. (ND)

  17. Use of Physio-Hydrological Units for SMOS Validation at the Valencia Anchor Station Study Area

    NASA Astrophysics Data System (ADS)

    Millán-Scheiding, C.; Antolín, C.; Marco, J.; Soriano, M. P.; Torre, E.; Requena, F.; Carbó, E.; Cano, A.; Lopez-Baeza, E.

    2009-04-01

    Probe measurements (with 3 repetitions each), covering the whole area. This experimental campaign permits the characterization of the soil moisture distribution within each physio-hydrological unit and results in a soil moisture map of the VAS site. All of it used for the validation of the aircraft observations done throughout the campaign. The ground measurement results obtained indicate that soil properties and vegetation cover are the parameters of the physio-hydrological units that most influence the moisture of the soil. This relationship will permit a more simple delimitation of the physio-hydrological Units and a reduction of the number of sample points for the calibration/validation of SMOS products. References: Lopez-Baeza, E., R. Acosta, M.C. Antolin, F. Belda, A. Cano, E. Carbo, M. Crapeau, A. Fidalgo S. Juglea, Y. Kerr, B. Martinez, C. Millan-Scheiding, D. Rodriguez, K. Saleh, J. Sanchis, J.-P. Wigneron(10), Other Contributors: J.E. Balling, C. Domenech, EOLAB, A.G. Ferreira J. Ferrer, J. Grant, J. Marco C. Narbon, B. Navascues, OCEANSNELL, E. Rodriguez-Camino, N. Skou, S. Søbjærg, P. Soriano, J. Tamayo, S. Tauriainen, E. Torre G. Torregrosa, A. Velazquez Blazquez, S. Vidal (2008): Validation of SMOS Products over Mediterranean Ecosystem Vegetation at the Valencia Anchor Station Reference Area. SMOS Cal/Val AO I.D. no. 3252. Experimental Plan SMOS Validation Rehearsal Campaign. University of Valencia, April 2008 Millan-Scheiding, C. (2006): Aproximación a la Humedad del Suelo en el Altiplano de Requena-Utiel. Preparación para la Campaña de Cal/Val de la Misión Espacial SMOS. Trabajo de Investigación de III Ciclo. Universidad de Valencia. Millán-Scheiding, C., C. Antolín, A. Cano, E. López-Baeza (2007): Uso de Unidades Fisio-Hidrológicas en la Monitorización de la Humedad del Suelo con SMOS. III Simposio Nacional sobre el Control de la Degradación de Suelos y la Desertificación. Costa Calma (Pájara), Fuerteventura, 16 al 20 de Septiembre 2007

  18. Spatial distribution and development of soils in tropical karst areas from the Peninsula of Yucatan, Mexico

    NASA Astrophysics Data System (ADS)

    Bautista, Francisco; Palacio-Aponte, Gerardo; Quintana, Patricia; Zinck, Joseph Alfred

    2011-12-01

    Better understanding of soil formation requires knowing the spatial distribution of the soils that allows constructing models of soil sequences in multiple directions along various types of gradients. This approach was applied to comprehend the soil formation from the soil distribution in the tropical karst areas of the Peninsula of Yucatan, Mexico. For soil mapping, a two-step methodology was followed. First, a geomorphic analysis was performed; subsequently, 382 soil profiles were reclassified and integrated into a geopedologic map. Additional soil survey was carried out in areas where soil information was lacking (123 soil profiles). Satellite images were used to identify flooded areas. After conducting numerous field verifications and analyses, landforms and soils were combined to make a soilscape map. Based on field observations and the soilscape map, soil development was analyzed on soil sequences. Four geomorphic environments were identified, karstic plains and hills with Leptosols, Cambisols, Luvisols, and Vertisols; coastal plains with Arenosols, Regosols, Solonchacks, and Histosols; fluvio-paludal plains with Gleysols, Histosols, Leptosols and Solonchacks; and tectono-karstic plains and hills with Leptosols, Cambisols, Luvisols, and Vertisols. Relevant soil forming factors in the Peninsula of Yucatan include time of emersion of the limestone platforms, climate, rock type, and macro- and micro-relief. Other factors such as groundwater level, fractures, also have an influence on soil formation. Karst development can be considered as a complex soil and relief forming factor. Terra Rossa soils as Leptosols, Cambisols, Luvisols, Nitisols and Vertisols in the Peninsula of Yucatan may be polygenic. In some cases, the theory of residual origin fits better the data than the theory of allochthonous origin; in other cases, it is the other way around.

  19. Combination of geo- pedo- and technogenic magnetic and geochemical signals in soil profiles - Diversification and its interpretation: A new approach.

    PubMed

    Szuszkiewicz, Marcin; Łukasik, Adam; Magiera, Tadeusz; Mendakiewicz, Maria

    2016-07-01

    Magnetic and geochemical parameters of soils are determined with respect to geology, pedogenesis and anthropopression. Depending on local conditions these factors affect magnetic and geochemical signals simultaneously or in various configurations. We examined four type of soils (Entic Podzol, Eutric Cambisol, Humic Cambisol and Dystric Cambisol) developed on various bedrock (the Tumlin Sandstone, basaltoid, amphibolite and serpentinite, respectively). Our primary aim was to characterize the origin and diversification of the magnetic and geochemical signal in soils in order to distinguish the most reliable methods for correct interpretation of measured parameters. Presented data include selected parameters, both magnetic (mass magnetic susceptibility - χ, frequency-dependent magnetic susceptibility - χfd and thermomagnetic susceptibility measurement - TSM), and geochemical (selected heavy metal contents: Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn). Additionally, the enrichment factor (EF) and index of geoaccumulation (Igeo) were calculated. Our results suggest the following: (1) the χ/Fe ratio may be a reliable indicator for determining changes of magnetic signal origin in soil profiles; (2) magnetic and geochemical signals are simultaneously higher (the increment of χ and lead and zinc was noted) in topsoil horizons because of the deposition of technogenic magnetic particles (TMPs); (3) EF and Igeo evaluated for lead and zinc unambiguously showed anthropogenic influence in terms of increasing heavy metal contents in topsoil regardless of bedrock or soil type; (4) magnetic susceptibility measurements supported by TSM curves for soil samples of different genetic horizons are a helpful tool for interpreting the origin and nature of the mineral phases responsible for the changes of magnetic susceptibility values. PMID:27112729

  20. Soil-geomorphology interactions and paleoclimatic implications of an ornithogenic soil toposequence on Rata Island, Fernando de Noronha Archipelago, South Atlantic

    NASA Astrophysics Data System (ADS)

    de Oliveira, Fábio Soares; Schaefer, Carlos Ernesto G. R.; Abrahão, Walter Antônio Pereira; Clemente, Eliane de Paula; Simas, Felipe Nogueira Bello

    2014-07-01

    The formation of highly phosphatized soils on sites of avian activity is a common feature of oceanic islands. We characterized a toposequence of phosphatic soils on Rata Island, to evaluate the soil genesis based on local topographic variations. For this purpose, four soils ranging from the upper hill down to the lowest landscape position on the island, representing a range of parent materials (basalt and calcareous sands), were analyzed. In the lowest landscape position a shallow Regosol was identified, strongly influenced by birds and marine sprays, developed on “karstified” Pleistocene calcarenites; the three other soils in the upper part of the toposequence are Ornithogenic Cambisols, ranging from a deep Cambisol profile on Basalt lava to intermediate Cambisols on mixed colluvial sediments of the basalt/calcareous. The lowermost Regosol is associated with a rugged landscape with strong calcarenite dissolution and karstification. The soil phosphatization is clearly an inherited process of the Late Quaternary age, when climate conditions were different. Initial weathering took place in the last interglacial period, under wetter conditions during which the Tertiary basalts were strongly weathered, leaving corestones in a saprolitic, oxidized mass. In the late Pleistocene, a gentle surface distributed these weathering products along the pediment slopes as colluvial materials, whereas in the coastal areas aeolian processes formed large sand dunes composed of reworked calcareous sands from marine sources during a time of very low sea level. During this time, widespread bird activity accounted for secondary apatite formation on the surface of calcareous oolites. Finally, the Holocene warming was accompanied by increasing sea level, enhanced tropical weathering, Fe and Al mobility and variscite formation superimposed on degraded Ca-phosphates, forming two phase phosphatic aggregates.

  1. Could be the future climate change an opportunity for the winegrowers? The case study of Aglianico wine in southern Italy.

    NASA Astrophysics Data System (ADS)

    Bonfante, Antonello; Basile, Angelo; Dragonetti, Giovanna; De Lorenzi, Francesca; De Mascellis, Roberto; Gambuti, Angelita; Giorio, Pasquale; Guida, Giampiero; Manna, Piero; Minieri, Luciana; Oliva, Marco; Orefice, Nadia; Terribile, Fabio

    2015-04-01

    Water deficit is a limiting factor to yield production and crop adaptation to future climate conditions. This is true for crops addressed mainly for biomass production (e.g. maize, wheat, etc.) but not for those where the quality is relevant. Specifically, in grapevine water stress (mid or limited) - occurring during specific phenological phases - is a factor to produce good quality wines. It induces for example the production of anthocyanins and aroma precursors. Therefore, the water stress, due to the future increase of temperature and the rainfall decrease, could represent an opportunity to increase winegrowers' incomes. The study was carried out in Campania region (Southern Italy), in an area vocated to high quality wines production (ZOVISA project: Viticultural zoning at farm scale) The study was realized in two different soils (calcisol and cambisol), under the same climate, on Aglianico cultivar, standard clone population on 1103 Paulsen rootstocks placed along a slope of 90 m length with 11% of gradient. The agro-hydrological model SWAP was calibrated and applied to estimate soil-plant water status at the various crop phenological phases for three vintages (2011-2013). Crop water stress index (CWSI) - estimated by the model - was related to physiological measurements (e.g leaf water potential), grape bunches measurements (e.g. sugar content) and wine quality (e.g. tannins). For both soils, the correlation between measurements and CWSI were high (e.g. -0.97** with sugar; 0.895* with anthocyanins in the skins). Then, the model was applied to future climate condition (2021-2051) obtained from statistical downscaling of GCM in order to estimate the effect of the climate on CWSI and hence on vine quality. The results show that the effects of the climate change on the vine quality is dependent by the soil, being relevant to the cambisol and less pronounced to the calcisol, with an expected improvement of wine quality in the cambisol.

  2. Soil-strain compatibility: the key to effective use of arbuscular mycorrhizal inoculants?

    PubMed

    Herrera-Peraza, Ricardo A; Hamel, Chantal; Fernández, Félix; Ferrer, Roberto L; Furrazola, Eduardo

    2011-04-01

    Consistency of response to arbuscular mycorrhizal (AM) inoculation is required for efficient use of AM fungi in plant production. Here, we found that the response triggered in plants by an AM strain depends on the properties of the soil where it is introduced. Two data sets from 130 different experiments assessing the outcome of a total of 548 replicated single inoculation trials conducted either in soils with a history of (1) high input agriculture (HIA; 343 replicated trials) or (2) in more pristine soils from coffee plantations (CA; 205 replicated trials) were examined. Plant response to inoculation with different AM strains in CA soils planted with coffee was related to soil properties associated with soil types. The strains Glomus fasciculatum-like and Glomus etunicatum-like were particularly performant in soil relatively rich in nutrients and organic matter. Paraglomus occultum and Glomus mosseae-like performed best in relatively poor soils, and G. mosseae and Glomus manihotis did best in soils of medium fertility. Acaulospora scrobiculata, Diversispora spurca, G. mosseae-like, G. mosseae and P. occultum stimulated coffee growth best in Chromic, Eutric Alluvial Cambisol, G. fasciculatum-like and G. etunicatum-like in Calcaric Cambisol and G. manihotis, in Chromic, Eutric Cambisols. Acaulospora scrobiculata and Diversispora spurca strains performed best in Chromic Alisols and Rodic Ferralsols. There was no significant relationship between plant response to AM fungal strains and soil properties in the HIA soil data set, may be due to variation induced by the use of different host plant species and to modification of soil properties by a history of intensive production. Consideration of the performance of AM fungal strains in target soil environments may well be the key for efficient management of the AM symbiosis in plant production. PMID:20552233

  3. Spatial variability of detrended soil plow layer penetrometer resistance transect in a sugarcane field

    NASA Astrophysics Data System (ADS)

    Pérez, Luis D.; Cumbrera, Ramiro; Mato, Juan; Millán, Humberto; Tarquis, Ana M.

    2015-04-01

    Spatial variability of soil properties is relevant for identifying those zones with physical degradation. In this sense, one has to face the problem of identifying the origin and distribution of spatial variability patterns (Brouder et al., 2001; Millán et al., 2012). The objective of the present work was to quantify the spatial structure of soil penetrometer resistance (PR) collected from a transect data consisted of 221 points equidistant. In each sampling, readings were obtained from 0 cm till 70 cm of depth, with an interval of 5 cm (Pérez, 2012). The study was conducted on a Vertisol (Typic Hapludert) dedicated to sugarcane (Saccharum officinarum L.) production during the last sixty years (Pérez et al., 2010). Recently, scaling approach has been applied on the determination of the scaling data properties (Tarquis et al., 2008; Millán et al., 2012; Pérez, 2012). We focus in the Hurst analysis to characterize the data variability for each depth. Previously a detrended analysis was conducted in order to better study de intrinsic variability of the series. The Hurst exponent (H) for each depth was estimated showing a characteristic pattern and differentiating PR evolution in depth. References Brouder, S., Hofmann, B., Reetz, H.F., 2001. Evaluating spatial variability of soil parameters for input management. Better Crops 85, 8-11. Millán, H; AM Tarquís, Luís D. Pérez, Juan Mato, Mario González-Posada, 2012. Spatial variability patterns of some Vertisol properties at a field scale using standardized data. Soil and Tillage Research, 120, 76-84. Pérez, Luís D. 2012. Influencia de la maquinaria agrícola sobre la variabilidad espacial de la compactación del suelo. Aplicación de la metodología geoestadística-fractal. PhD thesis, UPM (In Spanish). Pérez, Luís D., Humberto Millán, Mario González-Posada 2010. Spatial complexity of soil plow layer penetrometer resistance as influenced by sugarcane harvesting: A prefractal approach. Soil and Tillage

  4. Low intensity ultrasonic vibration amplitude as a tool for characterisation water stable soil aggregates

    NASA Astrophysics Data System (ADS)

    Mentler, Axel; Schomakers, Jasmin; Mayer, Herwig

    2013-04-01

    Ultrasonic dispersion of soil aggregates is a useful method to determine soil aggregate stability. Commercially available ultrasonic devices, however, operate at relatively high ultrasonic power, which hampers the analysis of less stable aggregates. Ultrasonic power is controlled in these devices with rather low accuracy and is used for correlation with the process of soil disaggregation. Self-developed ultrasonic equipment remedies these shortcomings by using low intensity ultrasonic vibrations. The vibration amplitude rather than the ultrasonic power is used to control the magnitude of loading in the dispersion experiment. Under well-defined geometrical conditions, the vibration amplitude strongly correlates with the magnitude of the acoustic pressure waves emitted into the fluid that cause disaggregation of soil particles. Samples of aggregates 2 000 - 250 μm of a degraded loamy silt chernozem, a loamy clay cambisol and a loamy sand cambisol had been collected under different tillage regimes in Austria: conventional tillage (CT) with mechanical weed control, reduced tillage (RT) and no tillage (NT) with inter cropping in winter. The cavitation threshold of gas saturated de-ionized water was determined at an ultrasonic vibration amplitude of 0.5-0.6 µm at 20 kHz frequency (acoustic pressure 0.9-1.1 bar) with a diode array spectrophotometer. Subsequent experiments were performed near this limit to be able to characterize weakly aggregated soils. Measuring soil aggregate stability (SAS) according to DIN norm showed greater aggregate stability of cambisol than of chernozem, however, could hardly show influences of tillage. Better results were obtained with the USAS (ultrasound soil aggregate stability) method, which on the one hand validated the SAS results. On the other hand it was possible to show an influence of soil tillage on aggregate stability, which significantly decreased from NT to RT and to CT for both soil types. The measurements correlated with total

  5. Transport of four pharmaceuticals in different horizons of three soil types

    NASA Astrophysics Data System (ADS)

    Kodesova, Radka; Svatkova, Paula; Klement, Ales; Jaksik, Ondrej; Golovko, Oksana; Fer, Miroslav; Kocarek, Martin; Nikodem, Antonin; Grabic, Roman

    2015-04-01

    Soil structure, which varies in different soil types and the horizons of these soil types, has a significant impact on water flow and contaminant transport in soils. Transport of many contaminants is in addition strongly influenced by their sorption on soil particles. Transport of four pharmaceuticals (sulfamethoxazole, trimethoprim, atenolol and carbamazepine) was studied in soil columns (a diameter of 10.5 cm and a height of 13 cm) taken from all diagnostic horizons of three different soil types (Haplic Luvisol, Greyic Phaeozem and Haplic Cambisol). The irrigation by water contaminated by a mixture of all four compounds followed by ponding infiltration of distilled water was simulated and water outflow and solute concentrations from the bottom of the soil sample was monitored in time. The highest infiltration rates were observed for soil samples from the Bt horizons of the Greyic Phaeozem that exhibited prismatic structure, followed by rates observed in the Ap horizons of the Haplic Luvisol, Greyic Phaeozem and Haplic Cambisol (due to their granular soil structure and presence of root channels). The lowest infiltration rate was measured for the Bw horizon of the Haplic Cambisol, which had a poorly developed soil structure and a low fraction of macropores. Compound discharge was however also highly affected by their sorption on solids. The highest mobility was observed for sulfamethoxazole followed by carbamazepine atenolol and trimethoprim, which corresponds to measured sorption isotherms. Mobility of ionizable compounds in different soil samples was influenced by pH (i.e. degree and form of their ionization) and sites available for absorption. Mobility of sulfamethoxazole decreased with decreasing pH (i.e. the largest sorption measured in horizons of the Haplic Cambisol). While mobility of atenolol and trimethoprim decreased with increasing base cation saturation, and with increasing organic matter content for carbamazepine. As result of both affects (i.e. soil

  6. Adsorption of glyphosate and aminomethylphosphonic acid in soils

    NASA Astrophysics Data System (ADS)

    Rampazzo, N.; Rampazzo Todorovic, G.; Mentler, A.; Blum, W. E. H.

    2013-03-01

    The results showed that glyphosate is initially adsorbed mostly in the upper 2 cm. It is than transported and adsorbed after few days in deeper soil horizons with concomitant increasing content of its metabolite aminomethylphosphonic acid. Moreover, Fe-oxides seem to be a key parameter for glyphosate and aminomethylphosphonic adsorption in soils. This study confirmed previous studies: the analysis showed lower contents of dithionite-soluble and Fe-oxides for the Chernozem, with consequently lower adsorption of glyphosate and aminomethylphosphonic as compared with the Cambisol and the Stagnosol.

  7. Desarrollo de un instrumento para medir percepciones sobre el contexto de construccion del conocimiento cientifico de estudiantes universitarios de nuevo ingreso

    NASA Astrophysics Data System (ADS)

    Garcia-Ramirez, Jaime Antonio

    En esta investigacion, se desarrollo un instrumento que permite medir percepciones relacionadas al contexto de constriccion del conocimiento cientifico. Se examinaron instrumentos existentes y se encontro que el VOSTS (Views on science, technology, and society), instrumento desarrollado empiricamente en Canada por Aikenhead, Ryan y Fleming, podia traducirse y validarse en el contexto cultural puertorriqueno. El instrumento es extenso, consta de 113 reactivos, cada uno con una premisa basica relacionada a la tematica ciencia, tecnologia y sociedad y un numero de alternativas relacionadas a la premisa que oscila entre siete y trece. Se delimito su utilizacion a los quince reactivos identificados por los autores como relacionados a la construccion social del conocimiento cientifico. Metodologicamente, se procedio a utilizar el modelo de adaptacion intercultural, que permite que el instrumento desarrollado satisfaga las dimensiones de equivalencia semantica, de contenido, tecnica, de criterio y conceptual, atemperado asi al instrumento original. Se cumplio con este proposito mediante la traduccion de la version original en ingles al espanol y viceversa. Se utilizaron comites para examinar la traduccion y la retro-traduccion del instrumento. Se realizo una prueba piloto con estudiantes universitarios de nuevo ingreso, utilizando el instrumento traducido para asegurar su intelegibilidad. La confiabilidad del instrumento se determino mediante la intervencion de un panel de expertos quienes clasificaron las distintas posiciones dentro de cada reactivo en: realista, con merito e ingenua; se transformaron estas opciones en valores numericos lo que permitio establecer una escala Likert para cada una. Se suministro el instrumento a una muestra de estudiantes universitarios de nuevo ingreso con caracteristicas similares a las de la poblacion puertorriquena en cuanto a ejecucion en las pruebas de aptitud verbal y matematica del College Board. Los resultados de sus contestaciones fueron transformados numericamente para poder obtener el coeficiente de correlacion de Spearman-Brown para el instrumento (0.661, p < 0.01). El analisis de las contestaciones de los estudiantes refleja percepciones diversas y, en algunos casos, contradictorias con respecto al contexto de construccion del conocimiento cientifico.

  8. Perspectivas sobre las escuelas charter: Una resena para padres de familia (Perspectives on Charter Schools: A Review for Parents). ERIC Digest.

    ERIC Educational Resources Information Center

    Donahoo, Saran

    Recently, charter schools have gained popularity with parents, students, and others as alternatives to public schools, but what are charter schools and what effects are they having? This Spanish-language Digest defines charter schools and clarifies some of the administrative and legal details surrounding such schools. The Digest also lays out some…

  9. Feedback Cheerleader, Mean-Spirited Feedback Estudio Critico Discursivo De Ideologias Sobre El Feedback Escrito En Un Departamento Universitario De Espanol En Estados Unidos

    ERIC Educational Resources Information Center

    Dominguez-Mujica, Maria Eugenia

    2012-01-01

    The aim of this research is to investigate ideologies that monitor and control styles of written feedback as well as discursive resources used in the expression of those ideologies. Using socio-cognitive analysis, a development of critical discourse studies, I have analyzed 44 sessions of chat on the Internet, 78 journal notes, 31 emails and 12…

  10. Producción masiva automatizada de la broca del café, Hypothenemus hampei (Coleoptera: Scolytidae) sobre la dieta artificial Cenibroca modificada.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An automated system for the mass rearing of coffee berry borer, CBB, Hypothenemus hampei (Ferrari) was developed at the National Biological Control Laboratory, USDA-ARS in the United States. A novel cell design of 32 cell trays (30 x 14.6 x 1.1 cm) and an automated diet dispenser were developed and ...

  11. La influencia del medio interestelar sobre la evolución del remanente de supernova (RSN) G53.6-2.2

    NASA Astrophysics Data System (ADS)

    Giacani, E. B.; Dubner, G.; Cappa, C.; Testori, J. C.

    G53.6-2.2 is a supernova remnant with an unusual morphology: in the radio band the overall shape can be described as two shells that overlap on the NW side of the remnant. The X-ray emission fills the source and peaks in the region where the radio rings overlap; while in the optical range the emission consists of filaments that correlate with portions of radio rings that overlap in the NW. The aim of the present project is to investigate the neutral hydrogen distribution around the remnant in search for signatures that allow to disclose the role of the surrounding gas in conditioning the observed morphology.

  12. Uso de los Datos de Biomonitoreo para Informar sobre la Evaluacion Infantil (American translation is: USING BIOMONITORING DATA TO INFORM EXPOSURE ASSESSMENT IN CHILDREN)

    EPA Science Inventory

    Discussing the challenges associated with estimating and interpreting toxicant exposures and health risks from biomonitoring data. This extended abstract was translated in Spanish and published in Acta Toxicologica Argentina.

  13. "Que vienen los lobos!" (Breve nota sobre el plural de los apellidos) ("May The Wolves Come:" [A Brief Note on the Plural of Surnames])

    ERIC Educational Resources Information Center

    Vivaldi, Gonzalo Martin

    1975-01-01

    This article discusses the problems that arise with the formation of plural forms of surnames in Spanish, problems both with morphology and with ambiguity. Suggestions as to how to lessen problems are made. (Text is in Spanish.) (CLK)

  14. Politica Nacional sobre Discapacidad: Un Informe del Progreso, Diciembre 2000-Diciembre 2001 (National Disability Policy: A Progress Report, December 2000-December 2001).

    ERIC Educational Resources Information Center

    National Council on Disability, Washington, DC.

    This report (written in Spanish) of the National Council on Disability (NCD) describes the nation's progress in advancing public policies to increase the inclusion, empowerment, and independence of people with disabilities in light of the Americans with Disabilities Act of 1990. The report covers December 2000 through December 2001. It reviews…

  15. Steppin' On Up: A Post-Secondary Guide for Migrant Students = Tomando Accion: Una Guia para los Estudiantes Migrantes Sobre Que Hacer Despues de la Escuela Secundaria.

    ERIC Educational Resources Information Center

    Western Stream Migrant Education Program Coordination Center, Portland, OR.

    This bilingual guide (English and Spanish) provides information for migrant students on postsecondary education. The guide includes information on: (1) career planning, involving self-exploration, occupational exploration, and strategies for reaching career objectives; (2) planning for postsecondary education during high school, including a…

  16. International Work Group for Indigenous Affairs Newsletter, July 1991-December 1992 = Boletin de Grupo Internacional de Trabajo sobre Asuntos Indigenas, Septiembre 1991-Diciembre 1992.

    ERIC Educational Resources Information Center

    IWGIA Newsletter, 1992

    1992-01-01

    This document contains seven consecutive English-language issues of the IWGIA Newsletter, from July 1991 through December 1992, followed by the seven corresponding issues in Spanish. These newsletters provide educators with a resource on the history, current conditions, and struggles for self-determination of indigenous peoples around the world.…

  17. Television Viewing = Lo que los padres de estudiantes dotados necesitan saber sobre ver...television. What Parents of Gifted Students Need To Know about...Series.

    ERIC Educational Resources Information Center

    Siegle, Del, Ed.

    This booklet (Practitioner's Guide), in both an English version and a Spanish version, is intended to help parents apply the findings of research to parental mediation of television viewing by their children, including gifted children. Research facts are briefly summarized and implications for the home are drawn. Suggestions for parents are…

  18. Manual sobre la Educacion en California para Padres de Idiomas Minoritarios = A Handbook on California Education for Language Minority Parents--Spanish/English Edition.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento. Bilingual Education Office.

    This bilingual handbook, presented in both Spanish and English, is designed to assist parents of language minority students who are residing in California. The book is part of the technical assistance effort of the State Department of Education to clarify the operations of the California schools to language minority parents so they can better…

  19. Manual sobre la Educacion en California para Padres de Idiomas Minoritarios (A Handbook on California Education for Language Minority Parents). Revised Edition. Spanish/English Edition.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento. Office of Bilingual Bicultural Education.

    The handbook, an update of the 1986 handbook, is designed for Spanish-speaking parents of California public school students, and answers commonly-asked questions about the state public education system and its services, particularly those of interest to this population. Information is presented in both Spanish-and English-language sections, in a…

  20. Sobre la convertibilidad de ciertos adjectivos en adverbios en el idioma espanol (Concerning the Convertibility of Some Spanish Adjectives into Adverbs).

    ERIC Educational Resources Information Center

    Zierer, Ernesto

    1971-01-01

    This paper considers Spanish adjectives and the possibility of converting some adjectives into adverbs, keeping the same general significance of a sentence. The conversion of an adjective into an adverb under these circumstances can be accomplished through a transformation which can be applied to a particular logical-semantic structure. The author…

  1. La investigacion sobre la calidad de los programas para ninos de hasta dos anos de edad (Research on Quality in Infant-Toddler Programs). ERIC Digest.

    ERIC Educational Resources Information Center

    Honig, Alice Sterling

    Concern about the quality of infant-toddler care programs has grown recently in response to two factors. The first is the need of employed parents for such care, and the second is research emphasizing the importance of brain development in the early years. This Spanish-language Digest introduces some of the many issues related to the quality of…

  2. Tax and Record Keeping Information for Family Child Care = Informacion Sobre los Impuestos y la Documentacion para el Cuidado Infantil en el Hogar.

    ERIC Educational Resources Information Center

    Gellert, Sandra

    This pamphlet from the Children's Foundation, in both English- and Spanish-language versions, provides advice to child care providers on record-keeping methods. The pamphlet also gives definitions and guidance on business expenses (100% deductible, shared personal and business, and depreciated capital expenses), time-space formula, self-employment…

  3. Parenting Information for Parents: Books 1-3 (Informacion Para Los Padres Sobre La Crianza De Los Hijos: Libros 1-3).

    ERIC Educational Resources Information Center

    Moreno, Steve

    These 3 booklets provide ideas, guidelines, and activities for establishing effective parenting and are part of a series of 22 booklets specifically designed to help parents understand their children and help them to learn. The first booklet (booklet #20) discusses preparation for parenthood, infant and toddler developmental stages, the importance…

  4. Kathy Finds Out about the Introduction of Solids. Mother-to-Mother Support = Josefa Descubre Conocimientos sobre la Introduccion de Solidos. Apoyo Madre a Madre.

    ERIC Educational Resources Information Center

    Magalhaes, Rebecca; Stone-Jimenez, Maryanne; Allen de Smith, Paulina; Smith, Natalia

    These magazine-sized booklets, one in English, one in Spanish, are in cartoon format and are designed to be used by people with limited literacy in English or Spanish. This booklet explains that exclusive breastfeeding means giving no water, liquids, or food; breast milk contains sufficient water to satisfy the baby's thirst; at about 6 months,…

  5. Guia para la Ensenanza Combinada de Ingles y Ciencia. Para Padres/sobre Padres. (A Guide to Teaching English and Science Together. For Parents/about Parents).

    ERIC Educational Resources Information Center

    Schwartz, Wendy

    In the past, students who knew only a little English (called limited English proficient, or LEP), were usually taught only low-level science and mathematics. Now, new science and mathematics teaching methods can help LEP students get a good education in both fields. This guide will help parents know if their children are learning as much as…

  6. Sobre la naturaleza de cinco candidatos a cúmulos abiertos ubicados próximos a la dirección del centro galáctico

    NASA Astrophysics Data System (ADS)

    Piatti, A. E.; Clariá, J. J.

    CCD BVI Johnson-Cousins observations obtained for 1759 stars in 4'×4' regions around the unstudied southern stellar aggregates Ruprecht 103, 124, 129, 146 and 166 are presented. The objects are described as open clusters in the catalogues of star clusters and associations of Alter et al. (1970) and LyngÅ (1987), as well as, in the ESO/Uppsala Survey of the ESO (B) Atlas (Lauberts 1982). Our analysis shows that none of these objects are genuine open clusters, except perhaps Ruprecht 166, since no clear main sequences (MSs) or other meaningful features can be seen in the extracted (V,B-V) and (V,V-I) colour-magnitude diagrams (CMDs). The star sequences seen in the distinct CMDs, specially for Ruprecht 124 and 129, are apparently formed by the superimposition of MS field stars affected by varying amounts of interstellar absorption and/or placed at different distances from the Sun. The CMDs of Ruprecht 166 present a pronounced variation in the luminosity function along the apparent MS, a fact from which we can infer the notion of these stars had a different origin. Star counts carried out within and outside the cluster candidate fields not only support the results that the objects do not present a significant number density contrast with respect to the Galactic disk, but also show that they do not appear to be candidate late stages of star cluster dynamical evolution. Several other stellar aggregates included in open cluster catalogues have previously been disproved as genuine physical systems (see, e.g., Carraro & Patat 1995, MNRAS, 276, 563; Carraro 2000, A&A, 357, 145; Piatti & Clariá 2001, A&A, 370, 931). Thus, the present work implies the potential likelihood of other wrongly classified open clusters.

  7. How To Talk to Your Teens and Children about AIDS = Como hablar con sus adolescentes y sus ninos sobre el SIDA.

    ERIC Educational Resources Information Center

    National PTA, Chicago, IL.

    Two brochures, one in English and one in Spanish, provide parents with basic information that will enable them to educate their children about Acquired Immune Deficiency Syndrome (AIDS). Contents address 11 questions: (1) What is AIDS? (2) How do you get AIDS? (3) How is AIDS not spread? (4) Who can get AIDS? (5) How can you tell if someone has…

  8. Producción masiva automatizada de la broca del café Hypothenemus hampei Ferrari (Coleóptera: Scolytidae) y de sus parasitoides sobre dietas artificiales

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article reviews the current state of knowledge concerning the mass rearing system of the coffee berry borer, cbb, Hypothenemus hampei (Ferrari) (Coleoptera: Scolytidae), and its African parasitoids: the ectoparasitoids Cephalonomia stephanoderis (Betrem) and Prorops nasuta ((Waterston) (Hymenop...

  9. Simposio sobre Educacion de Ninas: Evidencias, Temas, Acciones. Actas de sesiones. (Symposium on Girls Education: Evidence, Issues, Actions. Proceedings). (Washington, DC, May 17-18, 2000).

    ERIC Educational Resources Information Center

    Agency for International Development (IDCA), Washington, DC.

    This symposium highlighted core issues of controversy in girls' education and developed implications for policy and practice. Its evidence-based discussion forum encouraged dialogue, debate, and increased interaction and developed partnerships among academic institutions, nongovernmental organizations, multilateral development agencies, and other…

  10. Tips for Parents on Keeping Children Drug Free = Consejos para Los Padres Sobre Como Mantener a Los Hijos Libres de La Droga.

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC. Office of Intergovernmental and Interagency Affairs.

    Research shows that recent trends in youth drug use have stabilized; however, the rates of use remain at high levels. It has been shown that the earlier drug use is initiated, the more likely a person is to develop drug problems later in life. Youth substance abuse may lead to many other problems that affect not only the child, but also the…

  11. Resultados de una encuesta sobre posibles reformas ortograficas en el espanol del siglo XX (Results of a Survey Concerning Possible Orthographic Reforms in Twentieth Century Spanish)

    ERIC Educational Resources Information Center

    Varela Cuellar, Beatriz

    1976-01-01

    This article presents the results of a questionnaire sent to Spanish teachers regarding possible orthographic reforms in Spanish. Changes considered included elimination of certain letters and representation of each phoneme by only one letter. Responses to each question are classified and explained. (Text is in Spanish.) (CHK)

  12. Consideraciones sobre la investigacion hermeneutica en la educacion en lenguas y culturas extranjeras (Aspects of Applying a Hermeneutic Approach to Foreign Language and Culture Education).

    ERIC Educational Resources Information Center

    Zoreda, Margaret Lee

    Drawing on writings by recent post-modernist thinkers and semioticians, this paper focuses on a combination of hermeneutic and semiotic viewpoints and applies them to defining the nature of interpretation in an educational setting (e.g., text interpretation), the interpreter, and the essence of the act of comprehension and interpretation. The main…

  13. The Portugal Project: Adult Education in a Socio-economic Perspective. Paper for the Course, "Curso sobre Educacao de Adultos." Document No. 1.

    ERIC Educational Resources Information Center

    Erasmie, Thord

    Education is one of the major problems connected with the economic and social distribution of the total resources of the world. Examples of the educational gap between rich and poor countries can be seen by statistical comparisons between Peru and Czechoslavakia and between Guatemala and Denmark which show how unevenly educational resources are…

  14. Conservación de material histórico sobre papel en el Observatorio Astronómico de la Universidad Nacional de Córdoba

    NASA Astrophysics Data System (ADS)

    Laguzzi, N.; Tonini, A.; Andreoli, G.; Goldes, G.; Paolantonio, S.; Cequeira, F.; Landi, L.; Alba, J.

    At the recently created Astronomical Museum ``Pte. Sarmiento - Dr. Benjamin Gould", the task of preventive conservation of historic documents has been faced. These materials include: 1) letters exchanged between national authorities and the directors of the Observatory, during the first decades (1870-1880-1890); b) original observation logs from these very first times, containing astrometrical and photometrical data; c) a variety of ancient books and papers; d) administrative documents. The state of conservation of this patrimony was varied: since well-conserved books and letters, to highly degraded logs. The observation logs written by B. Gould and the astronomers who followed him had been stocked in a safe with a permanent humidity of about 70 %, without any ventilation and exposed to the attack of insects of the family ``dermestidae." These conditions could not be worse for the conservation of paper. In order to stop the proccess of degradation and create a healthy environment for written-paper conservation, a team was formed with personnel belonging to the Cultural Area of the Municipality. The tasks being performed on the observation logs are: 1) an initial, mechanical cleaning, performed once the material is extracted from the contaminated safe: by these means, adult insects and pupas are removed 2) a stage of about two weeks of duration, in which the logs are mantained in a vacuum chamber, in orden to completely eliminate the adult, pupa and egg stage insects by anoxia 3) the final mechanical cleaning 4) storage in a clean location. In order to perform these tasks, we work in collaboration with the Environmental Observatory of the City, and the group of Material-Science Research of Fa.M.A.F. Regarding the letters, a mechanical cleaning was performed. After that, the letters were digitized by means of a scanner, inventoried, put inside acid-free polipropylene envelops and filed for conservation, protected from intense light and external sources of contamination. Copies of these letters will be included as exhibits.

  15. Catalysts for Change: Three Case Studies of Quality Education Worldwide = Catalizadores del Cambio: Tres Casos de Estudio sobre la Educacion de Calidad en el Mundo

    ERIC Educational Resources Information Center

    Puriefoy, Wendy D.

    2007-01-01

    Public education is the cornerstone of democracy and is absolutely fundamental to a democratic, civil and prosperous society. Beyond the boundaries of the United States, other countries are working to provide quality education to their children through civil society institutions. In particular, there are three extraordinary organizations in Peru,…

  16. Teorí­as de primer y segundo orden sobre el potencial de ciertas figuras de equilibrio de cuerpos celestes

    NASA Astrophysics Data System (ADS)

    Gumbau, Manuel Forner

    2010-11-01

    Uno de los problemas que aborda la Mecánica Celeste es la determinación de las figuras de equilibrio de los cuerpos celestes. Para investigar su solución mediante métodos directos, se precisa evaluar el potencial generado por su autogravitación, el generado por su fuerza centrí­fuga y el generado por la fuerza de atracción entre los cuerpos. Los métodos clásicos de Finlay y Kopal que afrontan estos problemas, para determinar el potencial autogravitatorio en las configuraciones de equilibrio, emplean desarrollos en serie de los potenciales interior y exterior del potencial autogravitatorio. Estos métodos incurren en el error de suponer la convergencia en capas donde resulta cuestionable dicha convergencia para estos desarrollos en serie. En este trabajo se han elaborado unos algoritmos que contemplan toda la casuí&stica y que permiten una manipulación efic iente del producto de polinomios de Legendre, del producto de funciones asociada s de Legendre y del producto de armónicos esféricos como combinacióon lineal de ellos mismos, respectivamente. Se han obtenido, para primer y segundo orden en las amplitudes, los desarrollos correctos para los potencial es interior y exterior del potencial autogravitatorio para configuraciones de equilibrio aisladas, y , en primer orden de amplitudes, los mismos potenciales para los sistemas binarios próximos. Se ha elaborado un método analítico, en primer orden respecto de las amplitudes, para la determinación del potencial de marea en sistemas binarios próximos en el cual se manifiesta la forma de la componente secundaria del sistema

  17. Etnografía acelerada para transformar normas sociales sobre género y sexualidad en hombres puertorriqueños heterosexuales1,2

    PubMed Central

    Ortiz-Torres, Blanca; Rivera-Ortiz, Rafael J.; Mendoza, Sigrid

    2014-01-01

    Resumen La construcción de roles de género dominantes contribuyen al riesgo de contraer VIH, y por tal razón se ha urgido a que se integren las normas sociales relativas al género en las intervenciones preventivas del VIH. Este estudio pretende adaptar y desarrollar una intervención que facilite la transformación de normas sociales del género y de prácticas sexuales en hombres puertorriqueños. La intervención propone transformar normas sociales relacionadas al género y sexualidad en barras comunitarias utilizando el modelo de líderes de opinión. Luego de ser elegidos/as, los/as líderes de opinión diseminan mensajes integrando la importancia de relaciones equitativas entre parejas para la prevención del VIH. La primera fase de esta intervención es discutida en este artículo, la cual incluye un proceso de etnografía acelerada para identificar los escenarios comunitarios en los que podemos desarrollar esta intervención y permitirnos entender la cultura de las barras comunitarias. A partir de las observaciones etnográficas, pudimos: desarrollar un protocolo de seguridad para realizar las observaciones, desarrollar un perfil de la cultura de las barras, elegir las barras a participar en las dos condiciones del estudio y adaptar los instrumentos de la intervención para que respondieran a la particularidad de los/as participantes. PMID:25530828

  18. Que Sucede? Manual Informativo Sobre Rehabilitacion y Educacion Especial en Costa Rica (What's Happening? Informative Manual on Rehabilitation and Special Education in Costa Rica).

    ERIC Educational Resources Information Center

    de Mezerville, Gaston; And Others

    The manual, in Spanish, provides descriptions of rehabilitation, medical, and special education services; centers and institutions which offer physical and mental rehabilitation services; and lists of professionals and advocacy organizations in Costa Rica. Part 1 includes an overview of rehabilitation and special education, a short history of…

  19. Conversacion sobre "Tres tristes tigres". Una entrevista de Rita Guibert (A Conversation about "Three Sad Tigers". An Interview with Rita Guibert)

    ERIC Educational Resources Information Center

    Cabrera Infante, Guillermo

    1971-01-01

    Interview took place in London, England, on October 5, 1970 between Cuban writer Guillermo Cabrera Infante and journalist Rita Guibert. Special issue dedicated to contemporary Spanish American literature. (DS)

  20. Ahorre Energía: Consejos sobre el ahorro de dinero y energía en el hogar (Spanish Brochure), Energy Savers Guide

    SciTech Connect

    2014-09-01

    La versión en castellano de la guía del Departamento de Energía de los Estados Unidos que ayuda a consumidores a ahorrar energía y dinero en el hogar y en las carreteras. The Spanish-language version of U.S. Department of Energy's consumer guide to saving energy and money at home and on the road.

  1. The Dyslexia Handbook: Procedures Concerning Dyslexia and Related Disorders = Manual sobre la dislexia: Procedimientos relacionados con la dislexia y otros desordenes.

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin.

    This handbook, available in English and Spanish, contains the Texas State Board of Education's approved procedures concerning dyslexia and related disorders and information regarding the state's dyslexia statutes and their relation to the federal Rehabilitation Act of 1973, Section 504, and the Individuals with Disabilities Education Act. Chapters…

  2. Guia para Madres y Padres de Familia sobre Educacion Pre-Escolar a Temprana Edad (A Parents' Guide to Early Childhood Education).

    ERIC Educational Resources Information Center

    Dodge, Diane Trister; Phinney, Joanna

    This booklet for parents explains what children learn in preschools that employ the Creative Curriculum for Early Childhood and the ways in which learning can be reinforced at home. The first sections of the booklet explain the goals and philosophy of experience-based preschools. Goals include teaching children to love reading and school and to be…

  3. A+chieving Excellence. A Parent's Guide to Site-Based Decision Making. Noteworthy = A+lcanzar la Excelencia. Un manual para padres sobre como hacer decisiones. Notable.

    ERIC Educational Resources Information Center

    Hutchins, C. L.

    The parents' guide in English and Spanish versions, offers a synthesis of the Mid-Continent Regional Educational Laboratory's (McRel) "A+chieving Excellence," a 480-page manual on educational decision-making and management. Four sections examine four broad areas in which policies must be established for improving student achievement--efficiency,…

  4. A Parent's Guide to Infant/Toddler Programs = Guia para los padres sobre los programas de cuidado infantil de 0-3 anos.

    ERIC Educational Resources Information Center

    Dodge, Diane Trister; Dombro, Amy Laura; Colker, Laura J.

    Information on how warm and responsive care can help shape infants' and toddlers' development and their ability to learn can be reassuring for concerned parents. This guide, in English and Spanish versions, presents quality child care as a partnership between the child caregiver and the parents with the primary goal of benefiting the child. The…

  5. Pick and Choose: A Videotape Series on Nutrition for Migrant Families (Coja y Escoja: Peliculas para Television Sobre la Nutricion para las Familias Migratorias).

    ERIC Educational Resources Information Center

    1979

    One of the major problems faced by migrant workers throughout the United States is a lack of awareness of the relationship between proper diet and an individual's general health and well being. To help solve this problem was the major objective of the series "Pick and Choose." The three 15-minute programs in the series present information related…

  6. Borrowing Basics. FDIC Money Smart Financial Education Curriculum = Conceptos Basicos sobre Prestamos. FDIC Money Smart Plan de Educacion para Capacitacion en Finanzas.

    ERIC Educational Resources Information Center

    Federal Deposit Insurance Corp., Washington, DC.

    This module, an introduction to credit, is one of ten in the Money Smart curriculum, and includes an instructor guide and a take-home guide. It was developed to help adults outside the financial mainstream enhance their money skills and create positive banking relationships. It is designed to enable participants to decide when and how to use…

  7. Check It Out. FDIC Money Smart Financial Education Curriculum = Conceptos Basicos sobre Cuentas Corientes. FDIC Money Smart Plan de Educacion para Capacitacion en Finanzas.

    ERIC Educational Resources Information Center

    Federal Deposit Insurance Corp., Washington, DC.

    This module on how to choose and keep a checking account is one of ten in the Money Smart curriculum, and includes an instructor guide and a take-home guide. It was developed to help adults outside the financial mainstream enhance their money skills and create positive banking relationships. It is designed to enable participants to open and keep a…

  8. Effects of Fe oxide on N transformations in subtropical acid soils

    PubMed Central

    Jiang, Xianjun; Xin, Xiaoping; Li, Shiwei; Zhou, Junchao; Zhu, Tongbin; Müller, Christopher; Cai, Zucong; Wright, Alan L.

    2015-01-01

    Subtropical ecosystems are often characterized by high N cycling rates, but net nitrification rates are often low in subtropical acid soils. NO3−-N immobilization into organic N may be a contributing factor to understand the observed low net nitrification rates in these acid soils. The effects of Fe oxide and organic matter on soil N transformations were evaluated using a 15N tracing study. Soil net nitrification was low for highly acidic yellow soil (Ferralsols), but gross ammonia oxidation was 7 times higher than net nitrification. In weakly acidic purple soil (Cambisols), net nitrification was 8 times higher than in Ferralsols. The addition of 5% Fe oxide to Cambisols, reduced the net nitrification rate to a negative rate, while NO3−-N immobilization rate increased 8 fold. NO3−-N immobilization was also observed in Ferralsols which contained high Fe oxides levels. A possible mechanism for these reactions could be stimulation of NO3−-N immobilization by Fe oxide which promoted the abiotic formation of nitrogenous polymers, suggesting that the absence of net nitrification in some highly acid soils may be due to high rates of NO3−-N immobilization caused by high Fe oxide content rather than a low pH. PMID:25722059

  9. Evaluating the importance of surface soil contributions to reservoir sediment in alpine environments: a combined modelling and fingerprinting approach in the Posets-Maladeta Natural Park

    NASA Astrophysics Data System (ADS)

    Palazón, L.; Gaspar, L.; Latorre, B.; Blake, W.; Navas, A.

    2014-05-01

    Soil in alpine environments plays a key role in the development of ecosystem. Identify, maintain and preserve its resources, as well as recognize processes that would affect them are important and of practical interest. Environmental concerns about these fragile systems which are threatened by the human pressure and climatic change have stressed the need to gather information in soil erosion processes. As most mountain alpine environment the Benasque catchment is characterized by temperatures below freezing that can last from November to April, strong rainfall events and rugged topography. Indirect studies, such as combined model approaches, could be an alternative to evaluate soil erosion on these areas. In this study the complementary tools of Soil and Water Assessment Tool (SWAT) and fingerprinting procedure were used to assess an initial approach on soil erosion processes which take place in the area of the Posets-Maladeta National Park (Central Spanish Pyrenees). Soil erosion rates and sediment contribution of potential sediment sources (Kastanozem/Phaeozem; Fluvisol; Cambisol and channel bed sediments) were assessed. SWAT model identified Cambisols as the main source of sediment of the Benasque catchment with the highest specific sediment yields and Phaeozems and Fluvisols were identified as the lowest sediment contributors. Spring and winter performed the highest and lowest specific sediment yield, respectively. Fingerprinting procedure identified channel bed sediment and Fluvisols as the main sediment sources indicating the main influence of connectivity. The combined approach enabled us to better understand soil erosion processes in the Benasque alpine catchment.

  10. Thallium contamination of soils as affected by sphalerite weathering: A model rhizospheric experiment

    NASA Astrophysics Data System (ADS)

    Vaněk, Aleš; Grösslová, Zuzana; Mihaljevič, Martin

    2015-04-01

    The environmental stability of Tl-rich sphalerite in two contrasting soils was studied. Rhizospheric conditions were simulated to assess the risk associated with sulfide microparticles entering agricultural (top)soils. The data presented here clearly demonstrate a significant effect of 500 μM citric acid, a model rhizospheric solution, on ZnS alteration followed by enhanced Tl and Zn release. The relative ZnS mass loss after 28 days of citrate incubation reached 0.05 and 0.03 wt.% in Cambisol and Leptosol samples respectively, and was up to 4 times higher, compared to H2O treatments. Incongruent (i.e., substantially increased) mobilization of Tl from ZnS was observed during the incubation time. Generally higher (long-term) stability of ZnS with lower Tl release is predicted for soils enriched in carbonates. Furthermore, the important role of illite in the stabilization of mobilized Tl, linked with structural (inter)layer Tl-K exchange, is suggested. Thallium was highly bioavailable, as indicated by its uptake by white mustard; maximum Tl amounts were detected in biomass grown on the acidic Cambisol. Despite the fact that sulfides are thought as relatively stable phases in soil environments, enhanced sulfide dissolution and Tl/trace metal release (and bioaccumulation) can be assumed in rhizosphere systems.

  11. Impact of climate change on soil thermal and moisture regimes in Serbia: An analysis with data from regional climate simulations under SRES-A1B.

    PubMed

    Mihailović, D T; Drešković, N; Arsenić, I; Ćirić, V; Djurdjević, V; Mimić, G; Pap, I; Balaž, I

    2016-11-15

    We considered temporal and spatial variations to the thermal and moisture regimes of the most common RSGs (Reference Soil Groups) in Serbia under the A1B scenario for the 2021-2050 and 2071-2100 periods, with respect to the 1961-1990 period. We utilized dynamically downscaled global climate simulations from the ECHAM5 model using the coupled regional climate model EBU-POM (Eta Belgrade University-Princeton Ocean Model). We analysed the soil temperature and moisture time series using simple statistics and a Kolmogorov complexity (KC) analysis. The corresponding metrics were calculated for 150 sites. In the future, warmer and drier regimes can be expected for all RSGs in Serbia. The calculated soil temperature and moisture variations include increases in the mean annual soil temperature (up to 3.8°C) and decreases in the mean annual soil moisture (up to 11.3%). Based on the KC values, the soils in Serbia are classified with respect to climate change impacts as (1) less sensitive (Vertisols, Umbrisols and Dystric Cambisols) or (2) more sensitive (Chernozems, Eutric Cambisols and Planosols). PMID:27473773

  12. Composition and hydrophobic properties of organic matter in the densimetric fractions of soils from the Subpolar Urals

    NASA Astrophysics Data System (ADS)

    Dymov, A. A.; Milanovskii, E. Yu.; Kholodov, V. A.

    2015-11-01

    Organic matter features in the upper mineral horizons have been studied for four soils in the Subpolar Urals: humus-illuvial podbur (Entic Podzol), gleyic humus-illuvial podbur (Stagnic Entic Podzol), iron-illuvial podzol (Albic Podzol), and eluviated burozem (Leptic Cambisol). Organic matter pools have been separated by densimetric fractionation. The concentrations of carbon and nitrogen and the relative contributions of separate densimetric fractions to the total content of elements in the upper soil horizons reflect the genetic features of formation of the studied soils. The saturation of organic matter with nitrogen increases with increasing density of the fractions. The proportion of heavy fraction HF1 characterized by a high content of fine silt particles increases in the upper horizons of podburs (Entic Podzol, Stagnic Entic Podzol) and burozem (Leptic Cambisol). The contact wetting angles, which characterize the hydrophobic properties of soils, have been determined for the densimetric fractions and horizons of gleyic humus-illuvial podbur (Stagnic Entic Podzol) and iron-illuvial podzol (Albic Podzol). These values vary from 60 to 88° among the soil horizons and from 22 to 137° among the densimetric fractions. It has been found that the hydrophobic properties of the studied soil horizons are largely determined by the contents of free and occluded organic matter fractions.

  13. Soil Type-Dependent Responses to Phenanthrene as Revealed by Determining the Diversity and Abundance of Polycyclic Aromatic Hydrocarbon Ring-Hydroxylating Dioxygenase Genes by Using a Novel PCR Detection System▿ †

    PubMed Central

    Ding, Guo-Chun; Heuer, Holger; Zühlke, Sebastian; Spiteller, Michael; Pronk, Geertje Johanna; Heister, Katja; Kögel-Knabner, Ingrid; Smalla, Kornelia

    2010-01-01

    A novel PCR primer system that targets a wide range of polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenase (PAH-RHDα) genes of both Gram-positive and Gram-negative bacteria was developed and used to study their abundance and diversity in two different soils in response to phenanthrene spiking. The specificities and target ranges of the primers predicted in silico were confirmed experimentally by cloning and sequencing of PAH-RHDα gene amplicons from soil DNA. Cloning and sequencing showed the dominance of phnAc genes in the contaminated Luvisol. In contrast, high diversity of PAH-RHDα genes of Gram-positive and Gram-negative bacteria was observed in the phenanthrene-spiked Cambisol. Quantitative real-time PCR based on the same primers revealed that 63 days after phenanthrene spiking, PAH-RHDα genes were 1 order of magnitude more abundant in the Luvisol than in the Cambisol, while they were not detected in both control soils. In conclusion, sequence analysis of the amplicons obtained confirmed the specificity of the novel primer system and revealed a soil type-dependent response of PAH-RHDα gene-carrying soil bacteria to phenanthrene spiking. PMID:20495045

  14. Specific features of the genesis of automorphic soils of the northern forest-tundra (southeast of the Bol'shezemel'skaya tundra)

    NASA Astrophysics Data System (ADS)

    Rusanova, G. V.; Deneva, S. V.; Shakhtarova, O. V.

    2015-02-01

    Automorphic soils developed from sandy materials (podzolized podburs, (Entic Podzols) and iron-illuvial podzols (Haplic Podzols)) and loamy materials (organic cryometamorphic soils (Gelic Cambisols) and iron-illuvial svetlozems (Spodi-Stagnic Cambisols)) were studied in the northern forest-tundra zone. Podzolized podburs and podzols of tundra cenoses were less podzolized in comparison with the analogous soils developed under forest cenoses. This can be explained by a higher intensity of cryogenic processes favoring the fixation of iron-humus films on skeletal grains in the sandy soils of tundra cenoses. In the organic cryometamorphic soils, the illuviation of Al-Fe-humus compounds with the formation of bleached skeletans in the upper part of the mineral horizon was identified. The eluvial-illuvial differentiation of the soil mass diagnosed by the analyses of intraped mass was weakly pronounced. The features attributed to the activity of cryogenic processes were also described in these soils. Iron-illuvial svetlozems were characterized by the migration of iron compounds within the microprofile of podzol in the topsoil and by the specific well-structured cryometamorphic horizons in the lower part of the profile. The features inherited from the previous stages of soil development were identified in these soils.

  15. Effects of Fe oxide on N transformations in subtropical acid soils.

    PubMed

    Jiang, Xianjun; Xin, Xiaoping; Li, Shiwei; Zhou, Junchao; Zhu, Tongbin; Müller, Christopher; Cai, Zucong; Wright, Alan L

    2015-01-01

    Subtropical ecosystems are often characterized by high N cycling rates, but net nitrification rates are often low in subtropical acid soils. NO3(-)-N immobilization into organic N may be a contributing factor to understand the observed low net nitrification rates in these acid soils. The effects of Fe oxide and organic matter on soil N transformations were evaluated using a (15)N tracing study. Soil net nitrification was low for highly acidic yellow soil (Ferralsols), but gross ammonia oxidation was 7 times higher than net nitrification. In weakly acidic purple soil (Cambisols), net nitrification was 8 times higher than in Ferralsols. The addition of 5% Fe oxide to Cambisols, reduced the net nitrification rate to a negative rate, while NO3(-)-N immobilization rate increased 8 fold. NO3(-)-N immobilization was also observed in Ferralsols which contained high Fe oxides levels. A possible mechanism for these reactions could be stimulation of NO3(-)-N immobilization by Fe oxide which promoted the abiotic formation of nitrogenous polymers, suggesting that the absence of net nitrification in some highly acid soils may be due to high rates of NO3(-)-N immobilization caused by high Fe oxide content rather than a low pH. PMID:25722059

  16. Facilitated transport in European soils from the Euro-soil project

    SciTech Connect

    Dolfing, J.; Scheltens, S.D.

    1999-07-01

    The authors studied the response of five reference soils from the European Union (a vertic cambisol, rendzina, dystric cambisol, orthic luvisol, and orthic podzol, also known as Euro-soils 1 to 5) to the addition of HCl and NaOH. For all soils, which were incubated as soil slurries, the amount of organic carbon in solution remained essentially constant upon addition of HCl but increased upon addition of NaOH; that is, it was not the pH of the soil that determined changes in the solubilization of dissolved organic carbon but {Delta}pH. This observation has implications for the design of active soil management strategies, because increased amounts of dissolved organic carbon in the soil solution pose a risk for leaching of contaminants to deeper soil layers and eventually to the groundwater. In the past, much attention has been paid to the reaction of soils to acidification and changing land use as practiced when agricultural land is taken out of production. The observations reported here indicate that soil alkalization is not necessarily without environmental and toxicological risks.

  17. Thallium contamination of soils/vegetation as affected by sphalerite weathering: a model rhizospheric experiment.

    PubMed

    Vaněk, Aleš; Grösslová, Zuzana; Mihaljevič, Martin; Ettler, Vojtěch; Chrastný, Vladislav; Komárek, Michael; Tejnecký, Václav; Drábek, Ondřej; Penížek, Vít; Galušková, Ivana; Vaněčková, Barbora; Pavlů, Lenka; Ash, Christopher

    2015-01-01

    The environmental stability of Tl-rich sphalerite in two contrasting soils was studied. Rhizospheric conditions were simulated to assess the risk associated with sulfide microparticles entering agricultural (top)soils. The data presented here clearly demonstrate a significant effect of 500 μM citric acid, a model rhizospheric solution, on ZnS alteration followed by enhanced Tl and Zn release. The relative ZnS mass loss after 28 days of citrate incubation reached 0.05 and 0.03 wt.% in Cambisol and Leptosol samples respectively, and was up to 4 times higher, compared to H2O treatments. Incongruent (i.e., substantially increased) mobilization of Tl from ZnS was observed during the incubation time. Generally higher (long-term) stability of ZnS with lower Tl release is predicted for soils enriched in carbonates. Furthermore, the important role of silicates (mainly illite) in the stabilization of mobilized Tl, linked with structural (inter)layer Tl-K exchange, is suggested. Thallium was highly bioavailable, as indicated by its uptake by white mustard; maximum Tl amounts were detected in biomass grown on the acidic Cambisol. Despite the fact that sulfides are thought as relatively stable phases in soil environments, enhanced sulfide dissolution and Tl/trace element release (and bioaccumulation) can be assumed in rhizosphere systems. PMID:25265594

  18. Effect of soil weathering degree on the increase of cotton biomass and silicon mineralomass after amendment with biochar highly concentrated in phytoliths

    NASA Astrophysics Data System (ADS)

    Li, Zimin; Delvaux, Bruno; Yans, Johan; Dufour, Nicolas; Houben, David; Cornelis, Jean-Thomas

    2016-04-01

    Silicon (Si) is beneficial for plants, but not essential. It plays a crucial role in improving the yields of Si-accumulator crops through alleviating various biotic and abiotic stresses. The demand of Si fertilizers will likely increase due to soil desilication and removal of harvested biomass. Since plants accumulate Si in the form of readily soluble phytoliths, plant-derived biochar is considered as a Si source for Si accumulator crops. In addition to its beneficial effects on soil fertility and carbon sequestration, biochar is a promising cost-effective and environmentally friendly alternative to conventional Si amendments. Here, we study the impact of biochar materials with different phytolith concentrations on the bioavailability of Si in soils differing in weathering stage, and its effect on cotton biomass and Si mineralomass. Two biochar materials were used: Miscanthus x giganteus (Si concentration: 34.6 g/kg) and soft woody material (Si concentration: 0.9 g/kg). A conventional wollastonite (CaSiO3) treatment was carried for comparison purpose. The concentration of bioavailable Si was determined through 0.01 M CaCl2 extraction. Biochars were incorporated at the rate of 3% (w/w) in two soils: a slightly weathered Cambisol and a highly weathered Nitisol. The Miscanthus biochar ability to release bioavailable Si in the Cambisol (CaCl2 extractable Si/total Si concentration) is significantly smaller (0.9%) than the one of wollastonite (5.2%). In the highly weathered Nitisol, the Miscanthus biochar ability to release bioavailable Si is much larger (1.4%) than that of wollastonite (0.7%). Miscanthus biochar significantly increases the cotton biomass and Si mineralomass relative to soft wood biochar. The increase is larger in the highly weathered Nitisol than in the slightly weathered Cambisol. Principal component analyses and linear regression show that both the larger release rate of bioavailable Si and CEC are the main factors responsible for the increase of

  19. Stable Cu isotope fractionation in soils during oxic weathering and podzolization

    NASA Astrophysics Data System (ADS)

    Bigalke, Moritz; Weyer, Stefan; Wilcke, Wolfgang

    2011-06-01

    Copper stable isotope ratios are fractionated during various biogeochemical processes and may trace the fate of Cu during long-term pedogenetic processes. We assessed the effects of oxic weathering (formation of Cambisols) and podzolization on Cu isotope ratios (δ 65Cu). Two Cambisols (oxic weathered soils without strong vertical translocations of soil constituents) and two Podzols (soils showing vertical translocation of organic matter, Fe and Al) were analyzed for Cu concentrations, partitioning of Cu in seven fractions of a sequential extraction and δ 65Cu values in bulk soil. Cu concentrations in the studied soils were low (1.4-27.6 μg g -1) and Cu was mainly associated with strongly bound Fe oxide- and silicate-associated forms. Bulk δ 65Cu values varied between -0.57‰ and 0.44‰ in all studied horizons. The O horizons had on average significantly lighter Cu isotope compositions (-0.21‰) than the A horizons (0.13‰) which can either be explained by Cu isotope fractionation during cycling through the plants or deposition of isotopically light Cu from the atmosphere. Oxic weathering without pronounced podzolization in both Cambisols and a weakly developed Podzol (Haplic Podzol 2) caused no significant isotope fractionation in the single profiles, while a slight tendency to lower δ 65Cu values with depth was visible in all four profiles. This is the opposite depth distribution of δ 65Cu values to that we observed in hydromorphic soils (soils which show indication of redox changes because of the influence of water saturation) in a previous study. In a more pronounced Podzol (Haplic Podzol 1), δ 65Cu values and Cu concentrations decreased from Ah to E horizons and increased again deeper in the soil. Humus-rich sections of the Bhs horizon had higher Cu concentrations (2.8 μg g -1) and a higher δ 65Cu value (-0.18‰) than oxide-rich sections (1.9 μg g -1, -0.35‰) suggesting Cu translocation between E and B horizons as organo-Cu complexes. The

  20. To the soil genesis in tundra-forest ecotone belt in the Northeastern European Russia

    NASA Astrophysics Data System (ADS)

    Shakhtarova, Olga; Rusanova, Galina; Lapteva, Elena

    2013-04-01

    Ecotone belt representing the gradual transition between different bioclimatic zones (taiga and tundra) is of specific research interest. This transition zone is characterized by variety of landscapes and soil cover affected by climate changes which were accompanied with shifts of natural zones during Holocene. Paleoclimate changes had complicated the specifity of pedogenesis in the ecotone. The aim of the study was to reveal soil geneses in forest-tundra ecotone zone. The study area is characterized by drained topography and soil forming deposits represented by silty loams covering watersheds, permafrost is massive island and up to 50 m thick, permafrost table located at depths of 0,5-8 m. Vegetation cover is birch-spruce light forests where lichen-moss ground cover dominates, tree height is up to 4-6 m. Fe-illuvial svetlozoms (according to Russian classification 2004) were chosen as the study objects. According to WRB (2007) these soils are classified as Cambisols. In this soil study the complex approach was used, it includes (i) analysis of both structural organization and differentiation of functioning products on undisturbed monolith structure using mezo-micromorthologic methods; (ii) reveal of main soil-forming processes based on physical-chemical soil analysis. Quantitative chemical analysis has been conducted at an accredited laboratory "Ecoanalit" affiliated at Institute of Biology Komi SC UB RAS (Syktyvkar). Studied Cambisols are developed in upland forest sites located in the forest-tundra subzone. These soils are recognized by combination of podzolic, Fe-illuvial and cryomethamorphic horizons in the soil profile. Using of present-day methods and approaches for soil profile studies allowed to reveal the polygenesis of Cambisols which structure represents two pedogenic stages. The basis to determine these stages are the morphological features (structural organization, differentiation of cutan complex) as well as recent and inherited features of pedogenic

  1. Biotransformation of pesticides in saturated-zone materials

    NASA Astrophysics Data System (ADS)

    Hoyle, Blythe L.; Arthur, Ellen L.

    article est d'illustrer par des exemples la biotransformation des pesticides dans les nappes. Bien qu'il faille la considérer avec précaution, la base de données sur les pesticides dans les eaux souterraines de l'Agence américaine pour la protection de l'environnement a été utilisée pour centrer la discussion sur le potentiel de biotransformation du dibromoéthane (EDB), de l'atrazine, des désherbants acétanildés et de l'aldicarb, qui tous ont été détectés dans les nappes des États-Unis. Les résultats de plus de deux douzaines d'études indiquent qu'il existe un potentiel de biotransformation de ces pesticides dans les nappes, bien qu'entre chacun de ces pesticides il existe des différences très nettes dans la biotransformation. Ces variations sont en fait dues à la fois à des différences dans les méthodes expérimentales et dans les hétérogénéités dans les matériaux étudiés. Cependant, parce que les mécanismes de la biotransformation ne sont pas bien étudiés, il est en général impossible d'extrapoler les prédictions du potentiel de biotransformation à des sites d'étude spécifiques. Ces résultats soulignent la nécessité de mieux comprendre la régulation génétique microbienne des processus de biotransformation, pour que l'information génétique puisse être efficacement prise en compte dans les futures recherches sur le potentiel de biotransformation dans le sous-sol. Resumen Se han llevado a cabo un gran número de estudios para evaluar la contaminación por pesticidas en los acuíferos de los Estados Unidos de América. Sin embargo, las investigaciones sobre biotransformación de pesticidas en la zona saturada son mucho menos numerosas que en suelos. Como los resultados obtenidos en suelos no son directamente transladables a la zona saturada, el objetivo de este artículo es mostrar ejemplos de biotransformación de pesticidas en la zona saturada. Aunque debe tomarse con cautela, la base de datos "Pesticides in Ground Water

  2. Hydrogeology in North America: past and future

    NASA Astrophysics Data System (ADS)

    Narasimhan, T. N.

    2005-03-01

    'hydrogéologie est à la transition entre la volonté de découvrir de nouvelles ressources et l' exploitation la plus bénéfique au possible, et un management judicieux des ressources finies, interconnectées, qui sont vitales pour l' approvisionnement des hommes et autres formes de vie. Le futur de l' hydrogéologie sera dicté par la balance subtile dans laquelle intervient les cycles de l'hydrologie, de l'érosion, de la nutrition, et la décision d'une société technologique qui s'adapterait aux contraintes de la balance, ou qui continuerait d'exploiter les systèmes hydrologiques pour un bénéfice maximum. Par ailleurs il y a une nette tendance à inclure les aspects écologiques, les aspects environnementaux, et les changements humains qui pourraient être influencés par les modifications hydrogéologiques observées depuis une dizaine d'années. Este articulo es una retrospectiva sobre la evolución de la hidrogeología en Norte América en los pasados dos siglos, y una breve especulación de su futuro. La historia de la hidrogeología está marcada por desarrollos en muchos campos diferentes tal como hidrología de aguas subterráneas, mecánica de suelos, ciencia del suelo, geología económica, ingeniería del petróleo, geología estructural, geoquímica, geofísica, geología marina, y más recientemente, ecología. El campo se ha enriquecido por las contribuciones de investigadores distinguidos en todos esos campos. Actualmente, la hidrogeología se encuentra en transición de un estado de descubrir nuevos recursos y explotarlos eficientemente para un beneficio máximo, a un estado de gestión juiciosa de recursos finitos, interconectados, que son vitales para el sustento de humanos y otras cosas vivientes. El futuro de la hidrogeología posiblemente esté determinado por el balance sutil con el cual funcionan los ciclos nutricionales, erosionales e hidrológicos, y la decisión de una sociedad tecnológica para ya sea adaptarse a las restricciones impuestas por el

  3. Spanish Network on Effects of Wildfires on Soils. The view after 5 years of networking

    NASA Astrophysics Data System (ADS)

    Jordán, Antonio; Mataix-Solera, Jorge; Cerdà, Artemi

    2013-04-01

    incendios forestales sobre los suelos en España. El estado de la cuestión visto por los científicos españoles [Effects of wildfires on soils in Spain. The state of the question as seen by Spanish scientists; in Spanish]. Càtedra de Divulgació de la Ciència. Universitat de Valencia. 529 pp. ISBN: 978-84-370-7653-9. Díaz Raviña, M., Benito, E., Carballas, T., Fontúrbel, M.T., Vega , J.A.(Eds.). 2010. Research and post-fire Management: Soil Protection and Rehabilitation Techniques for Burnt Forest Ecosystems. IIAG (CSIC). Santiago de Compostela. 326 pp. ISBN: 978-84-8408-583-6. Jordán, A., Zavala, L.M. de la Rosa, J.M., Knicker, H., González-Pérez, J.A., González-Vila, F.J. (Eds.). 2009. Advances in forest fire effects on soils 2009. IRNAS-CSIC-Universidad de Sevilla. Sevilla. 144 pp. URI: http://hdl.handle.net/10261/18162. FUEGORED INTERNATIONAL MEETINGS FUEGORED2008. I International Meeting Effects of Wildfires son Soils. 03-05 December 2008. Valencia/Enguera/Alcoi, Spain. FUEGORED2009. II International Meeting Effects of Wildfires son Soils. 04-06 November 2009. Sevilla/Cortegana, Spain. FUEGORED2010. III International Meeting Effects of Wildfires son Soils Research and post-fire Management: Soil Protection and Rehabilitation Techniques for Burnt Forest Ecosystems 06-08 October 2010. Santiago de Compostela, Spain. FUEGORED2012. IV International Meeting Effects of Wildfires son Soils 24-27 October 2012. Puerto de la Cruz, Spain.

  4. Impacts of afforestation on groundwater resources and quality

    NASA Astrophysics Data System (ADS)

    Allen, Alistair; Chapman, Deborah

    2001-07-01

    que des pratiques forestières non coordonnées sont susceptibles d'exacerber les crues. La recharge des nappes est affectée par la foresterie, surtout à cause de prélèvements plus importants de l'eau du sol par les arbres et à cause de la capacité accrue des sols forestiers à retenir de l'eau, conduisant à de plus fortes teneurs en matières organiques. Les taux de recharge sous les forêts peuvent être réduits d'un dixième par rapport à la prairie ou à la lande. La qualité de l'eau souterraine peut être affectée par une acidification accrue et par une nitrification sous les forêts, provoquées pour une part par une fixation des polluants atmosphériques par le couvert forestier et pour une autre part par un dépôt plus important d'une litière plus fortement acide. Les taux de recharge plus lente des nappes sous les forêts conduisent à des retards importants dans la manifestation de la détérioration de la qualité de l'eau souterraine. Resumen. Se han iniciado los planes para duplicar la proporción de terrenos reforestados en Irlanda hacia el año 2035. El plan, impulsado por fines económicos, ignora los impactos potenciales medioambientales de la silvicultura, y, en particular, los impactos a los recursos de aguas subterráneas y a su calidad. Puesto que el 25 % del agua potable en Irlanda es suministrada por medio de aguas subterráneas, dichos impactos son importantes. Las investigaciones de campo indican que la reforestación lleva a una reducción de la escorrentía de hasta un 20 %, fundamentalmente por la interceptación de la lluvia en las copas de los árboles, mientras que la deforestación tiene el impacto opuesto. Las implicaciones son tales que las prácticas forestales descoordinadas pueden aumentar enormemente el riesgo de inundaciones. También la recarga a los acuíferos se ve afectada por la reforestación, debido, sobre todo, al uso del agua del suelo por los árboles y a la mayor capacidad de retención de los suelos en

  5. Soil wetting patterns of vegetation and inter-patches following single and repeated wildfires

    NASA Astrophysics Data System (ADS)

    González, Óscar; Malvar, Maruxa; van den Elsen, Erik; Hosseini, mohammadreza; Coelho, Celeste; Ritsema, Coen; Bautista, Susana; Keizer, Jan Jacob; Cerdà, Artemi

    2015-04-01

    cycles. Soil moisture content and antecedent rainfall were both correlated with SWR, although insufficient to predict the temporal variations. Antecedent and maximum soil moisture were close related with the SWR status and data analyses showed a top-down breaking mechanism on the SWR Acknowledgements. The research projects CASCADE FP7 (ENV.2011.2.1.4, www.cascade-project.eu) AND RECARE FP7 (n° 603498, http://recare-project.eu/) supported this research. References. Cerdá, A., Mataix-Solera, J., 2009. Incendios forestales en España. Ecosistemas terrestres y suelos. En: Efectos de los incendios forestales sobre los suelos en España. Cerda and Mataix-Solera (eds). Universidad de Valencia, Valencia (España). 529 pp. Keizer, J.J., Doerr, S.H., Malvar, M.C., Prats, S.A., Ferreira, R.S.V., Oñate, M.G., Coelho, C.O.A., Ferreira, A.J.D., 2008. Temporal variation in topsoil water repellency in two recently burnt eucalypt stands in north-central Portugal. Catena 74 (3), 192-204. Pausas, J., 2004. Changes in fire and climate in the eastern Iberian Peninsula (Mediterranean basin). Climatic Change, 63: 330-340. Prats, S.A., Malvar, M., Vieira, D.C.S., McDonald, L., Keizer, J.J. 2013. Effectiveness of hydromulching to reduce runoff and erosion in a recently burnt pine plantation in central Portugal. Land Degradation and Development. DOI: 10.1002/ldr.2236. Santos J.M., Verheijen F.G.A., Wahren F.T., Wahren A., Feger K.H., Bernard-Jannin L., Rial Rivas M.E., Keizer J.J., Nunes J.P. 2014. Soil Water Repellency dynamics in Pine and Eucalypt plantations in Portugal - A high resolution time series. Land Degradation & Development. DOI: 10.1002/ldr.2251.

  6. Hydrogeology in North America: past and future

    NASA Astrophysics Data System (ADS)

    Narasimhan, T. N.

    2005-03-01

    'hydrogéologie est à la transition entre la volonté de découvrir de nouvelles ressources et l' exploitation la plus bénéfique au possible, et un management judicieux des ressources finies, interconnectées, qui sont vitales pour l' approvisionnement des hommes et autres formes de vie. Le futur de l' hydrogéologie sera dicté par la balance subtile dans laquelle intervient les cycles de l'hydrologie, de l'érosion, de la nutrition, et la décision d'une société technologique qui s'adapterait aux contraintes de la balance, ou qui continuerait d'exploiter les systèmes hydrologiques pour un bénéfice maximum. Par ailleurs il y a une nette tendance à inclure les aspects écologiques, les aspects environnementaux, et les changements humains qui pourraient être influencés par les modifications hydrogéologiques observées depuis une dizaine d'années. Este articulo es una retrospectiva sobre la evolución de la hidrogeología en Norte América en los pasados dos siglos, y una breve especulación de su futuro. La historia de la hidrogeología está marcada por desarrollos en muchos campos diferentes tal como hidrología de aguas subterráneas, mecánica de suelos, ciencia del suelo, geología económica, ingeniería del petróleo, geología estructural, geoquímica, geofísica, geología marina, y más recientemente, ecología. El campo se ha enriquecido por las contribuciones de investigadores distinguidos en todos esos campos. Actualmente, la hidrogeología se encuentra en transición de un estado de descubrir nuevos recursos y explotarlos eficientemente para un beneficio máximo, a un estado de gestión juiciosa de recursos finitos, interconectados, que son vitales para el sustento de humanos y otras cosas vivientes. El futuro de la hidrogeología posiblemente esté determinado por el balance sutil con el cual funcionan los ciclos nutricionales, erosionales e hidrológicos, y la decisión de una sociedad tecnológica para ya sea adaptarse a las restricciones impuestas por el

  7. Biotransformation of pesticides in saturated-zone materials

    NASA Astrophysics Data System (ADS)

    Hoyle, Blythe L.; Arthur, Ellen L.

    article est d'illustrer par des exemples la biotransformation des pesticides dans les nappes. Bien qu'il faille la considérer avec précaution, la base de données sur les pesticides dans les eaux souterraines de l'Agence américaine pour la protection de l'environnement a été utilisée pour centrer la discussion sur le potentiel de biotransformation du dibromoéthane (EDB), de l'atrazine, des désherbants acétanildés et de l'aldicarb, qui tous ont été détectés dans les nappes des États-Unis. Les résultats de plus de deux douzaines d'études indiquent qu'il existe un potentiel de biotransformation de ces pesticides dans les nappes, bien qu'entre chacun de ces pesticides il existe des différences très nettes dans la biotransformation. Ces variations sont en fait dues à la fois à des différences dans les méthodes expérimentales et dans les hétérogénéités dans les matériaux étudiés. Cependant, parce que les mécanismes de la biotransformation ne sont pas bien étudiés, il est en général impossible d'extrapoler les prédictions du potentiel de biotransformation à des sites d'étude spécifiques. Ces résultats soulignent la nécessité de mieux comprendre la régulation génétique microbienne des processus de biotransformation, pour que l'information génétique puisse être efficacement prise en compte dans les futures recherches sur le potentiel de biotransformation dans le sous-sol. Resumen Se han llevado a cabo un gran número de estudios para evaluar la contaminación por pesticidas en los acuíferos de los Estados Unidos de América. Sin embargo, las investigaciones sobre biotransformación de pesticidas en la zona saturada son mucho menos numerosas que en suelos. Como los resultados obtenidos en suelos no son directamente transladables a la zona saturada, el objetivo de este artículo es mostrar ejemplos de biotransformación de pesticidas en la zona saturada. Aunque debe tomarse con cautela, la base de datos "Pesticides in Ground Water

  8. Anthropogenic transformation of soils in the Pokrovskoe-Streshnevo Park (Moscow) and adjacent residential areas

    NASA Astrophysics Data System (ADS)

    Prokof'eva, T. V.; Poputnikov, V. O.

    2010-06-01

    The diversity of soils within the specially protected natural territory of Pokrovskoe-Streshnevo in Moscow is discussed. The soils of this large park are not affected by the modern construction activities that delete the features inherited from the early stages of the anthropogenic transformation of soils in Moscow. They are characterized by the book-like type of soil memory, which makes it possible to trace several sequences of the anthropogenic soil transformation. The background natural soils-rzhavozems (Chromic Cambisols)—have been transformed into agrogenic soils (agrosols) and postagrogenic soils (postagrosols) under abandoned plowlands, into urbo-soils and urbanozems in the areas of former or modern settlements, and into techno-soils in the areas of active excavation works and engineering reclamation. The change in the character of the land use without the accumulation of osediments on the surface leads to the development of polygenetic soil horizons.

  9. Determinants of soil organic carbon pools in oak stands in northeastern Austria

    NASA Astrophysics Data System (ADS)

    Bruckman, Viktor J.; Hochbichler, Eduard; Yan, Shuai; Glatzel, Gerhard

    2010-05-01

    Recently deciduous forests in northeastern Austria received increased attention as potential sources of biomass for energetic utilisation. There are still substantial deficits in the knowledge on carbon pools, -sequestration and -dynamics at these forest sites. The aim of our study was therefore to identify the main determinants which control soil organic carbon (SOC) pools in differently managed Quercus petraea dominated stands. We used the chronosequence approach to test the influence of stand age and management on the SOC pool. Soil samples were systematically collected from 14 plots by means of a 70mm hand auger to a depth of max. 60cm and separated into five geometric horizons. Narrow O-layers and signs of active bioturbation on most sites suggest rapid carbon mineralisation. Carbon pools of the aboveground biomass, the O horizon as well as fine and coarse roots and decay were determined. Soils in our study are cambisols derived from fossil alluvial deposits and loess and calcic chernozems derived from loess. Total soil carbon was determined by means of dry combustion and subtraction of soil inorganic carbon (SIC, by means of the Scheibler-method) if present. Mean SOC contents ranged from 5.3 kg.m-2 to10.4 kg.m-2 in the entire study area. The highest contents were found in calcic chernozem sites (7.2-10.4 kg.m-2) followed by loamy cambisol (6.1-6.8 kg.m-2) and sandy cambisol sites (5.3-6.9 kg.m-2). Among three chronosequence sets, we found strong positive correlations with total nitrogen (Pearson correlation coefficients of +0.91 to +0.93, p<0.01) and medium strong positive correlations with fine root content (+0.27 to +0.42, p<0.01). In both cases, stronger correlations were observed at cambisol sites. Further medium correlations were found between SOC and decay (+0.23 to +0.42, p<0.01), but no influence of the soil type was observed. As expected, SOC contents decreased significantly with increasing soil depth. Tighter C/N ratios in deeper horizons suggest

  10. Kinetics of methane oxidation in selected mineral soils

    NASA Astrophysics Data System (ADS)

    Walkiewicz, A.; Bulak, P.; Brzeziñska, M.; Włodarczyk, T.; Polakowski, C.

    2012-10-01

    The kinetic parameters of methane oxidation in three mineral soils were measured under laboratory conditions. Incubationswere preceded by a 24-day preincubationwith 10%vol. of methane. All soils showed potential to the consumption of added methane. None of the soils, however, consumed atmospheric CH4. Methane oxidation followed the Michaelis-Menten kinetics, with relatively low values of parameters for Eutric Cambisol, while high values for Haplic Podzol, and especially for Mollic Gleysol which showed the highest methanotrophic activity and much lower affinity to methane. The high values of parameters for methane oxidation are typical for organic soils and mineral soils from landfill cover. The possibility of the involvement of nitrifying microorganisms, which inhabit the ammonia-fertilized agricultural soils should be verified.

  11. Determination of molybdenum in extracts of soil and sewage sludge CRMs after fractionation by means of BCR modified sequential extraction procedure.

    PubMed

    Zemberyová, M; Hagarová, I; Zimová, J; Barteková, J; Kuss, H-M

    2010-07-15

    A modified three-step sequential extraction procedure proposed by the Commission of European Communities Bureau of Reference (BCR) was applied to certified reference materials of three different soil groups (rendzina, luvisol, and cambisol) and sewage sludge of different compositions originating from a municipal water treatment plant in order to assess potential mobility and the distribution of molybdenum in the resulting fractions. In the soils examined, molybdenum was present almost entirely in the mineral lattice, the content of molybdenum in the fractions of the studied reference materials of sludges was predominant in the fraction, represents Mo bound to organic matter and sulphide. The internal check of accuracy was performed on the results of the sequential extraction by comparing of the extractable amounts of molybdenum in the sequential procedure with the results of the pseudototal digestion of original samples. The recovery ranged from 96 to 101% and the precision (RSD) in the extracts was below 10%. PMID:20602939

  12. Aspects of agricultural land use in Ireland

    NASA Astrophysics Data System (ADS)

    Lee, J.

    1986-02-01

    Ireland's soil regions consist largely of Luvisols, Cambisols, and Gleysols. Approximately 60% of Ireland's land area is subject to varying degrees of soil limitations. Twenty-five percent of the land area comprises wet lowland mineral soils. Ninety percent of Ireland's agricultural area comprises pasture, hay, and silage. Approximately 30% of the agricultural area is devoted to dairying, and 55% to cattle production. is devoted to dairying, and 55% to cattle production. Trends in agricultural land use indicate that tillage declined substantially while livestock showed a substantial increase particularly in the decade 1965 1975. Research concludes that over 2.8 million ha has a capacity to carry at least 100 LU/40 ha (100 acres). Levels of fertilizer use in Ireland are below EEC levels. The highest fertilizer use levels are associated with the eastern and southern areas of Ireland. Tillage crops occupy only 10% of the agricultural area, while they account for 26% of tertilizer and lime use.

  13. Delineation of colluvial soils in different soil regions

    NASA Astrophysics Data System (ADS)

    Zádorová, Tereza; Penížek, Vít; Vašát, Radim

    2015-04-01

    Colluvial soils are considered to be the direct result of accelerated soil erosion in agricultural landscape, resulting in accumulation of humus-rich soil material in terrain depressions and toe slopes. They represent an important soil cover element in landscapes influenced by soil erosion and form an important soil organic carbon (SOC) pool. Delineation of colluvial soils can identify areas with high sediment input and potential deep organic carbon storage and thus improve our knowledge on soil mass and SOC stock redistribution in dissected landscapes. Different prediction methods (ordinary kriging, multiple linear regression, supervised fuzzy classification, artificial neural network, support vector machines) for colluvial soils delineation have been tested in three different soil regions (Cambisol, Luvisol and Chernozem) at two scales (plot and watershed) in the Czech Republic. The approach is based on exploitation of relationship between soil and terrain units and assumes that colluvial soil can be defined by particular range of terrain attributes values. Terrain attributes derived from precise DEMs were used as predictors in applied models. The soil-terrain relationship was assessed using a large dataset of field investigations (300 cores at each plot and 100 cores at each watershed). Models were trained at plot scale (15-33 ha) and the best performing model was then calibrated and validated at watershed scale (25-55 km2). The study proved high potential of terrain variables as predictors in colluvial soil delineation. Support vector machines method was the best performing method for colluvial soil occurrence prediction at all the three sites. However, significant differences in performance have been identified among the studied plots. The best results were obtained in Luvisol region where both determination coefficient and prediction accuracy reached the highest values. The model performance was satisfactory also in Chernozem region. The model showed its

  14. Temporal variability of selected chemical and physical properties of topsoil of three soil types

    NASA Astrophysics Data System (ADS)

    Jirku, Veronika; Kodesova, Radka; Nikodem, Antonin; Muhlhanselova, Marcela; Zigova, Anna

    2013-04-01

    Temporal variability of soil properties measured in surface horizons of three soil types (Haplic Cambisol, Greyic Phaeozem, Haplic Luvisol) was studied in years 2007, 2008, 2009 and 2010. Undisturbed soil samples were taken every month to evaluate the actual field soil-water content, bulk density, porosity and hydraulic properties. The grab soil samples were taken every month to evaluate aggregate stability using the WSA (water stable aggregates) index, pHH2O and pHKCl, soil organic matter content and quality. Unsaturated hydraulic conductivity for pressure head of -2 cm was measured directly in the field using the minidisk tension infiltrometer. In addition soil structure was documented on micromorphological images. In some cases, the similar trends of the pHH2O , pHKCl , A400/A600, rod, P, θfield or WSA values were observed in different soils. Interestingly, the similar trends were found mostly for the Haplic Cambisol and the Greyic Phaeozem despite the fact that these soils considerably differed (different soil substrate, pedogenetic processes, etc.) and that variable crops (winter wheat and spring wheat) were planted at both locations during two years (2007 and 2006). Mostly different trends were observed for the Haplic Luvisol and the Greyic Phaeozem (soil of the same substrate). The reason could be attributed to a high vulnerability of the Haplic Luvisol to soil degradation in comparison to that of the Greyic Phaeozem. Parameters of hydraulic properties were highly variable and did not show similar trends for different soils (except the saturated soil water content and the slope of the retention curve at the inflection point for Haplic Cambisol and Greyic Phaeozem). Soil structure, aggregate stability and soil hydraulic properties were interrelated and depended on plant growth, rainfall compaction and tillage. The drier conditions in some soils positively influenced the soil aggregate stability, the slope of the retention curve at the inflection point and

  15. Exchangeable Cations in the Soils of Quercus Dominated Forests in Northeastern Austria

    NASA Astrophysics Data System (ADS)

    Yan, Shuai; Bruckman, Viktor J.; Glatzel, Gerhard

    2010-05-01

    In northeastern Austria there is a growing interest in increased utilisation of forest biomass for energy. This study focuses on soil properties and nutrient pool characteristics in deciduous forests in order to provide advice for forest management. We (i) quantified selected exchangeable cations in the soils of our study area and (ii) identified the effects of stand age, soil type, soil depth and soil pH on exchangeable cations and cation exchange capacity (CEC). Nine permanent Quercus petraea dominated plots on sandy, clayey cambisols and calcic chernozem were selected for our study. From each plot 18 soil samples were collected in a systematic grid by means of a soil corer with 70 mm diameter to a maximum depth of 60 cm. Soil pH, exchangeable mineral elements K, Ca, Mg, Na, Mn, Al, and Fe were determined in five geometric soil horizons. Statistical analysis showed that (i) forest age did not influence the exchangeable K content of the sandy soils; (ii) the exchangeable K content decreased with increasing stand age in clayey cambisols; (iii) exchangeable K, Na and Mg were higher in calcic chernozems and clayey cambisols (iv) exchangeable Fe was significantly higher in sandy forest soils except in the 60-80 years old stand; (v) exchangeable Fe was below detection limit in calcic chernozem soils. A comparison of exchangeable cations revealed that (i) Ca is the key element of base cations (ii) the content of base cations is strongly significantly higher in calcic chernozem soils (iii) calcic chernozem soils have the highest CEC. CEC ranged from 38 to 190 μmol/g in the entire research area. Base cations, acid cations and CEC differ with soil depth as followed (i) in sandy and clayey cambisols, CEC had a minimum in 20 cm depth and then increased with soil depth to 50 cm; (ii) CEC decreased steadily with soil depth in calcic chernozems. As expected, CEC is significantly positively correlated (Pearson correlation coefficient 0.661, P<0.01) with the pH of the soil. The

  16. Sound Wave Energy Resulting from the Impact of Water Drops on the Soil Surface

    PubMed Central

    Ryżak, Magdalena; Bieganowski, Andrzej; Korbiel, Tomasz

    2016-01-01

    The splashing of water drops on a soil surface is the first step of water erosion. There have been many investigations into splashing–most are based on recording and analysing images taken with high-speed cameras, or measuring the mass of the soil moved by splashing. Here, we present a new aspect of the splash phenomenon’s characterization the measurement of the sound pressure level and the sound energy of the wave that propagates in the air. The measurements were carried out for 10 consecutive water drop impacts on the soil surface. Three soils were tested (Endogleyic Umbrisol, Fluvic Endogleyic Cambisol and Haplic Chernozem) with four initial moisture levels (pressure heads: 0.1 kPa, 1 kPa, 3.16 kPa and 16 kPa). We found that the values of the sound pressure and sound wave energy were dependent on the particle size distribution of the soil, less dependent on the initial pressure head, and practically the same for subsequent water drops (from the first to the tenth drop). The highest sound pressure level (and the greatest variability) was for Endogleyic Umbrisol, which had the highest sand fraction content. The sound pressure for this soil increased from 29 dB to 42 dB with the next incidence of drops falling on the sample The smallest (and the lowest variability) was for Fluvic Endogleyic Cambisol which had the highest clay fraction. For all experiments the sound pressure level ranged from ~27 to ~42 dB and the energy emitted in the form of sound waves was within the range of 0.14 μJ to 5.26 μJ. This was from 0.03 to 1.07% of the energy of the incident drops. PMID:27388276

  17. Sediment yield from gullies, riparian mass wasting and bank erosion in the Upper Konto catchment, East Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Rijsdijk, Anton; Bruijnzeel, L. A. (Sampurno); Prins, Th. M.

    2007-06-01

    Upland watershed rehabilitation programmes in Indonesia have faced increased scrutiny for not delivering the desired reductions in downstream sedimentation rates. Partly this reflects the fact that conservation measures have not been widely adopted or maintained by upland farmers, mainly for socio-economic reasons. Another potential explanation is that sediment contributions by gullying, (riparian) mass wasting and bank erosion have been seriously underestimated or even ignored. This paper presents estimates of sediment contributions by gullies, riparian mass wasting and bank erosion in the upland volcanic Konto catchment, East Java. Runoff and sediment yield from gullies were studied in two areas with contrasting soils and land use. Gullies in the Maron area (few gullies, Andic Cambisols, maize and rice cultivation on stable broad-based terraces) were related to improper drainage of trails, roads and yards. In the Binangsri area (more widespread gullying, Eutric Cambisols, onion cultivation on forward-sloping terraces), gullying was further enhanced by the practice of downslope furrowing to promote field drainage. Estimated annual sediment yields from the two areas were strikingly different at 22-26 and 50-87 Mg ha - 1 , respectively. Riparian mass wasting was estimated to contribute ca. 4% of total sediment yield at Maron and 8-19% in the main gully system at Binangsri, with the higher value in the latter case representing the effect of extreme rainfall in the latter half of the rainy season. Short-term wet season rates of gully wall retreat at Binangsri suggested a contribution by bank erosion of ca. 3% (8% including extreme events). As such, 11-27% of the annual sediment yield at Binangsri was estimated to have come from sources other than surface erosion. Substantial volumes of sediment (29-107 Mg km - 1 of river length) were also added to streams bordered by irrigated rice fields ( sawah) in non-gullied areas, mainly through the collapse of the lowermost

  18. Organic carbon distribution, speciation, and elementalcorrelations within soil microaggregates: applications of STXM and NEXAFSspectroscopy

    SciTech Connect

    Wan, Jiamin; Tyliszczak, Tolek; Tokunaga, Tetsu K.

    2007-03-15

    Soils contain the largest inventory of organic carbon on the Earth's surface. Therefore, it is important to understand how soil organic carbon (SOC) is distributed in soils. This study directly measured SOC distributions within soil microaggregates and its associations with major soil elements from three soil groups (Phaeozem, Cambisol, and Ultisol), using scanning transmission X-ray microscopy (STXM) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy at a spatial resolution of 30 nm. Unlike previous studies, small intact soil microaggregates were examined directly in order to avoid preparatory procedures that might alter C speciation. We found that SOC exists as distinct particles (tens to hundreds of nm) and as ubiquitous thin coatings on clay minerals and iron-oxides coatings. The distinct SOC particles have higher fractions of aromatic C than the coatings. NEXAFS spectra of the C coatings within individual microaggregates were relatively similar. In the Phaeozem soil, the pervasive spectral features were those of phenolic and carboxylic C, while in the Cambisol soil the most common spectral feature was the carboxyl peak. The Ultisol soil displayed a diffuse distribution of aromatic, phenolic, and carboxylic C peaks over all surfaces. In general, a wide range of C functional groups coexist within individual microaggregates. In this work we were able to, for the first time, directly quantify the major mineral elemental (Si, Al, Ca, Fe, K, Ti) compositions simultaneously with C distribution and speciation at the nm to {mu}m scale. These direct microscale measurements will help improve understanding on SOC-mineral associations in soil environments.

  19. Disturbances can control fine-scale pedodiversity in old-growth forests: is the soil evolution theory disturbed as well?

    NASA Astrophysics Data System (ADS)

    Šamonil, P.; Vašíčková, I.; Daněk, P.; Janík, D.; Adam, D.

    2014-10-01

    Biota-soil interactions in natural ecosystems are the subject of considerable research. Our hypothesis is that individual trees play a significant role through biomechanical and biochemical disturbances affecting soil formation in temperate forests, resulting in a complex spatial pattern of disturbance regimes and a close relationship between disturbance histories and soil units. In Žofínský Prales (Czech Republic) - the fourth oldest, continuously protected reserve in Europe and the first site of global research network SIGEO (Smithsonian Institution Global Earth Observatories) in continental Europe - we compared extensive dendrochronological, soil and pit-mound microtopography data both temporally and spatially from an area of anthropogenically unaffected 42 ha collected from 2008-2012. These data sets differ in terms of information complexity and length of memory: tree cores contain complex information about the disturbance history of the past 350 years, footprints of disturbances from the uprooting of a specific tree can persist 1700 years, and soils represent an extensive composite phenotype that has been developing for at least the entire postglacial period (10 500 years). On average, 6.18-13.41% of the canopy on individual soil units was disturbed per decade. Even though the "backbone" of key events in the development of the forest ecosystem remained the same (e.g. the 1870s, 1880s and 1980s), the internal structure of disturbance history often differed among soil units; the most exceptional were Gleysols and Histosols, where important feedback from soil to trees was expected. However, the characteristics of treethrow dynamics as well as the frequencies of stronger releases in core series also significantly differed along a gradient of terrestrial soil weathering and leaching (Haplic Cambisols - Dystric Cambisols - Entic Podzols - Albic Podzols). These results suggest the existence of several disturbance regimes within the forest, controlling fine

  20. Trace element concentrations in leachates and mustard plant tissue (Sinapis alba L.) after biochar application to temperate soils.

    PubMed

    Kloss, Stefanie; Zehetner, Franz; Oburger, Eva; Buecker, Jannis; Kitzler, Barbara; Wenzel, Walter W; Wimmer, Bernhard; Soja, Gerhard

    2014-05-15

    Biochar application to agricultural soils has been increasingly promoted worldwide. However, this may be accompanied by unexpected side effects in terms of trace element (TE) behavior. We used a greenhouse pot experiment to study the influence of woodchip-derived biochar (wcBC) on leaching and plant concentration of various TEs (Al, Cd, Cu, Pb, Mn, As, B, Mo, Se). Three different agricultural soils from Austria (Planosol, Cambisol, Chernozem) were treated with wcBC at application rates of 1 and 3% (w/w) and subsequently planted with mustard (Sinapis alba L.). Soil samples were taken 0 and 7 months after the start of the pot experiment, and leachate water was collected twice (days 0 and 54). The extractability (with NH4NO3) of cationic TEs was decreased in the (acidic) Planosol and Cambisol after wcBC application, whereas in the (neutral) Chernozem it hardly changed. In contrast, anionic TEs were mobilized in all three soils, which resulted in higher anion concentrations in the leachates. The application of wcBC had no effect on Al and Pb in the mustard plants, but increased their B and Mo concentrations and decreased their Cd, Cu and Mn concentrations. A two-way analysis of variance showed significant interactions between wcBC application rate and soil type for most TEs, which indicates that different soil types may react differently upon wcBC application. Correlation and partial correlation analyses revealed that TE behavior was primarily related to soil pH, whereas the involvement of other factors such as electrical conductivity (EC), organic carbon (OC) content and dissolved organic carbon (DOC) was found to be more soil and TE-specific. The application of wcBC may be a useful strategy for the remediation of soils with elevated levels of cationic TEs, but could lead to deficiencies of cationic micronutrients and enhance short-term translocation of anionic TEs towards the groundwater at high leaching rates. PMID:24631613

  1. Sound Wave Energy Resulting from the Impact of Water Drops on the Soil Surface.

    PubMed

    Ryżak, Magdalena; Bieganowski, Andrzej; Korbiel, Tomasz

    2016-01-01

    The splashing of water drops on a soil surface is the first step of water erosion. There have been many investigations into splashing-most are based on recording and analysing images taken with high-speed cameras, or measuring the mass of the soil moved by splashing. Here, we present a new aspect of the splash phenomenon's characterization the measurement of the sound pressure level and the sound energy of the wave that propagates in the air. The measurements were carried out for 10 consecutive water drop impacts on the soil surface. Three soils were tested (Endogleyic Umbrisol, Fluvic Endogleyic Cambisol and Haplic Chernozem) with four initial moisture levels (pressure heads: 0.1 kPa, 1 kPa, 3.16 kPa and 16 kPa). We found that the values of the sound pressure and sound wave energy were dependent on the particle size distribution of the soil, less dependent on the initial pressure head, and practically the same for subsequent water drops (from the first to the tenth drop). The highest sound pressure level (and the greatest variability) was for Endogleyic Umbrisol, which had the highest sand fraction content. The sound pressure for this soil increased from 29 dB to 42 dB with the next incidence of drops falling on the sample The smallest (and the lowest variability) was for Fluvic Endogleyic Cambisol which had the highest clay fraction. For all experiments the sound pressure level ranged from ~27 to ~42 dB and the energy emitted in the form of sound waves was within the range of 0.14 μJ to 5.26 μJ. This was from 0.03 to 1.07% of the energy of the incident drops. PMID:27388276

  2. Impact of varying soil structure on transport processes in different diagnostic horizons of three soil types.

    PubMed

    Kodesová, Radka; Vignozzi, Nadia; Rohosková, Marcela; Hájková, Tereza; Kocárek, Martin; Pagliai, Marcello; Kozák, Josef; Simůnek, Jirka

    2009-02-16

    When soil structure varies in different soil types and the horizons of these soil types, it has a significant impact on water flow and contaminant transport in soils. This paper focuses on the effect of soil structure variations on the transport of pesticides in the soil above the water table. Transport of a pesticide (chlorotoluron) initially applied on soil columns taken from various horizons of three different soil types (Haplic Luvisol, Greyic Phaeozem and Haplic Cambisol) was studied using two scenarios of ponding infiltration. The highest infiltration rate and pesticide mobility were observed for the Bt(1) horizon of Haplic Luvisol that exhibited a well-developed prismatic structure. The lowest infiltration rate was measured for the Bw horizon of Haplic Cambisol, which had a poorly developed soil structure and a low fraction of large capillary pores and gravitational pores. Water infiltration rates were reduced during the experiments by a soil structure breakdown, swelling of clay and/or air entrapped in soil samples. The largest soil structure breakdown and infiltration decrease was observed for the Ap horizon of Haplic Luvisol due to the low aggregate stability of the initially well-aggregated soil. Single-porosity and dual-permeability (with matrix and macropore domains) flow models in HYDRUS-1D were used to estimate soil hydraulic parameters via numerical inversion using data from the first infiltration experiment. A fraction of the macropore domain in the dual-permeability model was estimated using the micro-morphological images. Final soil hydraulic parameters determined using the single-porosity and dual-permeability models were subsequently used to optimize solute transport parameters. To improve numerical inversion results, the two-site sorption model was also applied. Although structural changes observed during the experiment affected water flow and solute transport, the dual-permeability model together with the two-site sorption model proved to be

  3. La Ninez en Puerto Rico: Resultados del Censo 2000. Un informe de KIDS COUNT/PRB sobre el Censo 2000 (Children in Puerto Rico: Results from the 2000 Census. A KIDS COUNT/PRB Report on Census 2000).

    ERIC Educational Resources Information Center

    Mather, Mark

    This Spanish-language report provides data on children in Puerto Rico based on the 2000 U.S. Census. It compares the situation of Puerto Rico's children with that of children living in the 50 states and the District of Columbia, noting how characteristics of Puerto Rican children have changed over time. Between 1990-2000, the number of Puerto…

  4. [The EMECAM project: a discussion of the results in the participating cities. Estudio Multicéntrico Español sobre la Relación entre la Contaminación Atmosférica y la Mortalidad].

    PubMed

    Ballester Díez, F; Sáez Zafra, M; Pérez-Hoyos, S; Daponte Codina, A; Bellido Blasco, J B; Cañada Martínez, A; Abad Díez, J M; Pérez Boíllos, M J; Alonso Fustel, M E; Taracido Trunk, M; Aguinaga Ontoso, I; Guillén Pérez, J J; Ordóñez Iriarte, J M; Saurina Canals, C; Tenías Burillo, J M

    1999-01-01

    This article draws a comparison and provides a discussion of the findings resulting from the local analyses of the 14 cities participating in the EMECAM Project. An analysis is made of the time series related to mortality, pollutants (particles in suspension, SO2, NO2, O3 and CO), temperature and other factors taken from records of public institutions. By using Poisson autoregressive regression, an estimate has been made of the short-term relationship between the number of deaths and the air pollution indicators in each one of the following cities: Barcelona, metropolitan area of Bilbao, Cartagena, Castellón, Gijón, Huelva, Madrid, Pamplona, Seville, Oviedo, Valencia, Vigo, Vitoria and Saragossa. The findings reveal the air pollution figures in our country to be similar to those of other European cities. The levels of the different pollutants point toward road traffic as being the main source of most of this pollution. A relationship has been found between the mortality and different pollutants in most cities, although the results are not homogeneous among the cities and show variability in the different causes under study. In some cities, especially in those having smaller populations, there have been no findings providing any evidence of a relationship, or the findings themselves are not highly consistent. The meta-analysis will provide estimates for all of the cities as a whole and will allow the possibility of making a more clear-cut assessment of the time lag impact of air pollution on the mortality. Worthy of special mention is the participation in this project of public health officers as actively involved researchers. PMID:10410614

  5. Distintas Modalidades de Aproximar la Educacion al Mundo Productivo: Efectos sobre Variables Psico-Sociales en los Alumnos (Distinct Modalities in Approaching Education for the Productive World: Effects of Socio-psychological Variables on Students).

    ERIC Educational Resources Information Center

    Hidalgo, Abelardo Castro; Carrasco, Decler Martinez; Alegria, Jorge Alegria; Elevancini, Cecilia Maldonado

    2000-01-01

    States that since the 1990s, professional technical education has produced profound transformations in the relationship between education and work in Chile. Examines in a study how modalities of bringing students to the world of work have affected students' socio-psychological characteristics in comparison to training received from traditional…

  6. A Look at the Decisions Hispanic Families Make after the Diagnosis of Deafness = Un estudio sobre las decisiones que toman las familias hispanas despues de un diagnostico de sordera.

    ERIC Educational Resources Information Center

    Steinberg, Annie; Bain, Lisa; Li, Yuelin; Montoya, Louise; Ruperto, Vivian

    This study, written in both English and Spanish, examined the decision-making process of Hispanic families living in the United States who have a child with a hearing loss. Twenty-nine families in four different geographical areas shared their experiences in learning about their child's disability, searching for appropriate interventions, and…

  7. Can We Talk? Helping Families Talk about Self-Esteem, Sex, and Peer Pressure. Training Package = Conversamos? Ayudando a Familias a Hablar sobre la Autoestima, el Sexo, y la Presion de los Amigos. Paquete de Capacitacion.

    ERIC Educational Resources Information Center

    Cappello, Dominic; Newberry, Jerald

    This English and Spanish language multimedia packet comprises an educational curriculum designed to help families talk about self-esteem, sex, and peer pressure with their children in grades 4 through 8. The packet consists of a planning and training manuals, family activity books, and a videotape. The curriculum is comprised of four parent…

  8. A Baseline Study of Strategies to Promote Critical Thinking in the Preschool Classroom (Un Estudio de Base sobre Estrategias para la Promoción de Pensamiento Critico en las Aulas de Preescolar)

    ERIC Educational Resources Information Center

    León, Jenny Melo

    2015-01-01

    The purpose of this study was to identify the different incidents of critical thinking in five preschool classrooms in one school, and the instructional strategies preschool teachers employed in the development of children's critical thinking. The participants in this study were five self-contained preschool teachers and their corresponding…

  9. Sobre un Cambio Sintactico en el Espanol Canario: del Indicativo al Subjuntivo y Condicional (Concerning a Syntactic Change in the Spanish of the Canary Islands: From the Indicative to the Subjunctive and Conditional).

    ERIC Educational Resources Information Center

    Serrano, Maria Jose

    1995-01-01

    Many sociolinguistic studies validate the importance of the relationship among social variables that satisfactorily explain the correlation between linguistic and social phenomena. The intersection of sex, sociocultural level, and age initiates syntactic change that first appears in the vernacular and progresses to the accepted standard. (52…

  10. Directory of Adult Education Periodicals. Seventh Revised Edition. = Repertoire des Periodiques sur l'Education des Adultes. Septieme Edition Revisee. = Repertorio de Periodicos sobre Educacion de Adultos. Septima Edicion Revisada.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France). Div. of Primary Educ., Literacy & Adult Educ., Educ. in Rural Areas

    Intended as a reference for persons seeking documentation on adult education, this directory provides a list of professional journals and newsletters--international, national, and regional--appearing regularly and dealing either exclusively or substantially with information and activities relating to adult education. This seventh revised edition…

  11. Directory of Adult Education Periodicals. Sixth Revised Edition = Repertoire des Periodiques sur l'Education des Adultes. Sixieme Edition Revisee = Repertorio de Periodicos sobre Educacion de Adultos. Sexta Edicion Revisada.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France). Div. of Literacy, Adult Education and Rural Development.

    This directory lists approximately 175 adult education periodicals published in Africa, Arab states, Asia and the Pacific, Europe, North America, Latin America and the Caribbean, and other international areas. Within each category, periodicals are further divided into the individual countries in which they are published. Each entry may provide…

  12. [Treatment of type 2 diabetes mellitus in patients with chronic kidney disease. Grupo de Trabajo para el Documento de Consenso sobre el tratamiento de la diabetes tipo 2 en el paciente con enfermedad renal crónica].

    PubMed

    Gómez-Huelgas, Ricardo; Martínez-Castelao, Alberto; Artola, Sara; Górriz, José Luis; Menéndez, Edelmiro

    2014-01-21

    Chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM) are highly prevalent chronic diseases, which represent an important public health problem and require a multidisciplinary management. T2DM is the main cause of CKD and it also causes a significant comorbidity with regard to non-diabetic nephropathy. Patients with diabetes and kidney disease represent a special risk group as they have higher morbi-mortality as well as higher risk of hypoglycemia than diabetic individuals with a normal kidney function. Treatment of T2DM in patients with CKD is controversial because of the scarcity of available evidence. The current consensus report aims to ease the appropriate selection and dosage of antidiabetic treatments as well as the establishment of safety objectives of glycemic control in patients with CKD. PMID:24268912

  13. Adolescents' Awareness of Environmental Care: Experiences When Writing Short Descriptive Texts in English (Concientización de los adolescentes sobre el cuidado ambiental: experiencias al escribir textos descriptivos cortos en inglés)

    ERIC Educational Resources Information Center

    Jaramillo Urrutia, Lorena; Medina Gutiérrez, Ana Stella

    2011-01-01

    Today it is necessary to approach environmental topics with students in an interdisciplinary manner to mitigate the environmental damages that the Earth is suffering. In this paper we report an action-research and innovation study aimed at sensitizing students with respect to the care and preservation of the environment through the writing of…

  14. Guia para Evaluar y Ubicar a Estudiantes de Idiomas Minoritarios. Para Padres/sobre Padres (A Guide to Assessing and Placing Language Minority Students. For Parents/about Parents).

    ERIC Educational Resources Information Center

    Schwartz, Wendy

    This guide helps parents understand how schools assess their child's English language ability and suggests ways for them to help schools place their children in the most useful language program. All districts must decide which students to test, and then how to test them. Some schools attempt to find out the English skills of all students, and…

  15. Regulando la Enfermedad a través de la Definición y la Restricción: Profesionales de la Salud Hablan sobre el VIH/SIDA1

    PubMed Central

    Rivera, Souhail Malavé; Díaz, Nelson Varas

    2009-01-01

    Resumen Las profesiones de la salud tienen un papel social dual. Por un lado, velan por el mantenimiento de la salud de la población protegiendo el bien común. Por el otro, dictaminan las formas saludables, y por lo tanto socialmente apropiadas, de ser, actuar y pensar. Este último papel, está más ligado al control social de la población que a una preocupación altruista hacia la misma. A través de esta supervisión y control, se construyen los sujetos a los cuales todos/as debemos aspirar a ser para gozar de aceptación social. Los/as profesionales de la salud han jugado un rol protagónico en dicho proceso, siendo los agentes que delimitan y definen lo que es enfermo vs. saludable, útil vs. inútil, apropiado vs. inapropiado. En el caso de la epidemia del VIH, este esfuerzo se ha hecho cada vez más vigente ya que estos/as profesionales juegan un papel importante en el tratamiento de las personas que viven con VIH/SIDA (PVVS). Sin embargo, su función está plasmada de definiciones que sirven para criminalizar a las PVVS. El objetivo de este estudio fue explorar la manera en que una muestra de profesionales de la salud en Puerto Rico construyen a las PVVS. Con este propósito, entrevistamos 80 profesionales de la salud y estudiantes de estas profesiones. Estas entrevistas fueron grabadas, transcritas y sometidas a un análisis de discurso. Los resultados reflejaron que según las personas participantes: 1) la PVVS no es una persona “normal” o funcional bajo los estándares sociales debido a que su salud no se los permite, 2) representa una carga para la sociedad incluyendo familiares, amigos/as, el mundo del trabajo, e incluso para el gobierno, 3) debe ser vigilada porque representa un riesgo para la persona seronegativa que es descrita como saludable y productiva, y 4) necesita que su salud y conducta sexual sean controladas por vía legal y/o por las personas que representan las instituciones sociales, como lo son los/as profesionales de la salud. En este artículo abordamos el potencial rol de la psicología para servir como vehículo de reconstrucción de dichas nociones, tomando en consideración su propio rol en la formación y mantenimiento de dicho sujeto socialmente deseable. PMID:22025907

  16. Mision Informacion: Entrevista a Empleados en el Lugar donde Trabajan; Observar a Obreros mientras Trabajan; Programa sobre Experiencia Laboral (Mission Information: Worksite Interview, Shadow Community Workers, Work Experience Program). CHOICE (Challenging Options in Career Education).

    ERIC Educational Resources Information Center

    Putnam and Northern Westchester Counties Board of Cooperative Educational Services, Yorktown Heights, NY.

    The work-study guide is the third volume in the advanced level of a career education curriculum for elementary-secondary migrant children. Complementing the secondary level job information text and a workbook about decision making and self-awareness, the work-study guide is designed to accompany work exploration and experience programs. It…

  17. Grupo de Trabajo Para la Preparacion del Proyecto Sobre el Desarrolo de Servicias de Bibliotecas y de Informacion Cientifica y Tecnica (Working Group for the Preparation of the Proposal on the Development of Library Services and Scientific and Technical Information).

    ERIC Educational Resources Information Center

    Oficina de Educacion Iberoamericana, Madrid (Spain).

    The Office of Iberoamerican Education, an intergovernmental body based on educational and cultural cooperation for the purpose of disseminating information, documentation, advice, and assistance in the field of education, co-sponsors (with UNESCO) the work represented in this study of library and information planning and facilities in the Andean…

  18. The Latinas' Guide to the Information Superhighway: A Bilingual Guide for Latinas by Latinas = Guia para Mujeres Latinas sobre la Supercarretera de la Informacion: Una Guia Bilingue para Latinas por medio de Latinas.

    ERIC Educational Resources Information Center

    MANA, A National Latina Organization, Washington, DC.

    This guide to the Internet is designed to give Latinas basic information on computers and the information superhighway. Written in both Spanish and English, the guide begins by defining the Internet and making some suggestions about acquiring access to a computer. Among the topics discussed are how to choose an Internet service provider, how to…

  19. Students' Perceptions of the Impact of CLIL in a Mexican BA Program (Percepciones de los estudiantes sobre el impacto de la enseñanza de contenido-lengua integrados en un programa de pregrado en México)

    ERIC Educational Resources Information Center

    Asomoza, Alejandra Nuñez

    2015-01-01

    Content and language integrated learning is an innovative pedagogical approach used in educational institutions worldwide. This study considers information and experiences from various settings in order to explore content and language integrated learning within the Mexican context. This study reports the perceptions of students in a BA program.…

  20. Como Promover el Exito de las Ninas y las Minorias en las Ciencias y en las Matematicas. Para Padres/sobre Padres (How To Promote the Science and Mathematics Achievement of Females and Minorities. For Parents/about Parents).

    ERIC Educational Resources Information Center

    Schwartz, Wendy

    Some minority and female students traditionally have not been given the help they need to enroll and succeed in mathematics and science classes. Now, however, various approaches are available to give these students the extra attention they need. Parents can help children develop an interest in science and mathematics by: (1) identifying role…

  1. Receta para el Exito. Una Guia Actualizada para Padres sobre el Mejoramiento de las Escuelas de Colorado y Logros Estudiantiles (Recipe for Success: An Updated Parents' Guide to Improving Colorado Schools and Student Achievement).

    ERIC Educational Resources Information Center

    Taher, Bonnie; Durr, Pamela

    This Spanish language guide describes ways that parents can help improve student achievement and school quality. It answers such questions as: how to choose the right early-education opportunity for a preschooler; how to make sure a 5-year-old is ready for school; how to help a daughter do well in school; how to work with a daughter's or son's…

  2. International Symposium on Visually Handicapped Infants and Young Children: Birth to Seven (2nd, Aruba, 1987). "The First Steps." Proceedings = Simpasio Internacional sobre Ninos Visualmente Deficientes de Nacimiento hasta Siete Anos (2nd, Aruba, 1987). "Los Primeros Pasos."

    ERIC Educational Resources Information Center

    Palmer, Lillian, Ed.; And Others

    This symposium focused on the special needs of visually handicapped infants and young children. Texts of 48 papers are presented, including keynote addresses by W. Aubrey Webson ("The First Steps") and Heather Hewitt ("First Steps--Parenting, Prevention and Programming"). Regional reports are provided for Japan, Bangladesh, the Middle East, the…

  3. Kathy Talks with Other Mothers about Breastfeeding an Older Baby. Mother-to-Mother Support = Josefa Habla con Otras Mamas sobre el Amamantar a un Bebe Mayorcito. Apoyo Madre a Madre.

    ERIC Educational Resources Information Center

    Magalhaes, Rebecca; Stone-Jimerez, Maryanne; Allen de Smith, Paulina; Smith, Natalia

    These magazine-sized booklets, one in English, one in Spanish, are in cartoon format and designed to be used by people with limited literacy in English or Spanish. The book explains that a 1- or 2-year old breastfed baby is comforted by breastfeeding, breast milk continues to have nutritional value (even if the mother becomes pregnant), and that…

  4. Actas de la 4th mesa redonda sobre investigacion en "Lenguas Extranjeras" en la Universidad Autonoma Metropolitana 1996. (Proceedings from the 4th Roundtable on Investigation in Foreign Languages in the Autonomous Metropolitan University 1996).

    ERIC Educational Resources Information Center

    Zoreda, Margaret Lee, Comp.; Diop, Mamoudou Si, Comp.; Vivaldo Lima, Javier, Comp.

    The articles included in this volume were selected as exemplary papers from the conference in Mexico. The goal of the forum was to provide an opportunity for researchers from the three branches of the Universidad Autonoma Metropolitana (UAM) to meet and discuss research projects currently in progress at the university. The works presented here…

  5. Edades y metalicidades de cinco cúmulos estelares proyectados en dirección a la Nube Menor de Magallanes: implicaciones sobre los procesos de formación y evolución de estos sistemas

    NASA Astrophysics Data System (ADS)

    Piatti, A. E.; Santos, J. F. C.; Clariá, J. J.; Bica, E.; Sarajedini, A.; Geisler, D.

    Washington photometry of the 5 star clusters Lindsay 32, Lindsay 38, Kron 28, Kron 44 and Lindsay 116 and their surrounding fields located towards the Small Magellanic Cloud (SMC) is presented for the first time. From the color-magnitude diagrams, cleaned from field stars contamination, the cluster and SMC field reddenings, ages and metallicities are determined. The ages - derived from the difference in the T1 magnitude betweem the giant clump and the Main Sequence turnoff point - vary between 2 and 6 Gyr, and the metallicities ([Fe/H]) between -1.65 and -1.10. Lindsay 116 is located closer to the Large Magellanic Cloud (LMC) than to the SMC and its fundamental parameters suggests a higher probability of belonging to the LMC. The results obtained in this work, combined with previous estimates of age and metallicity for other seven clusters, allow us to draw the following conclusions: (1) There does not exist an age-position relation in the SMC, but a age-metallicity one. (2) The chemical enrichment in the SMC has been very efficient during the last 5 Gyr. (3) The SMC clusters formation and evolution can be better represented by a bursting star formation process than by a continuum star formation mechanism.

  6. Head Start Program Performance Standards on Services for Children with Disabilities (45-CFR 1308) [and] Normas de Ejecucion del Programa Head Start Sobre Servicios para Ninos con Discapacidades (45-CFR 1308).

    ERIC Educational Resources Information Center

    Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

    This document consolidates, clarifies, and updates federal regulations on Head Start services for children with disabilities. The regulations are designed to complement the Head Start Program Performance Standards governing services to all enrolled children. Specifically, these regulations require Head Start programs to: (1) design comprehensive…

  7. Manual de Adiestramiento sobre Terapia de Rehidratacion Oral y Control de las Enfermedades Diarreicas (Oral Rehydration Therapy and the Control of Diarrheal Diseases). Training for Development. Peace Corps Information Collection & Exchange Training Manual No. T-53.

    ERIC Educational Resources Information Center

    Clark, Mari; And Others

    This Spanish-language manual was developed to train Peace Corps volunteers and other community health workers in Spanish-speaking countries in oral rehydration therapy (ORT) and the control of diarrheal diseases. Using a competency-based format, the manual contains three training modules (organized in seven sessions) that focus on interrelated…

  8. La Seccion de Investigacion sobre Educacion Medica de la Facultad de Medicina de la Universidad National Autonoma de Mexico (The Medical Education Investigation Section of the School of Medicine of UNAM).

    ERIC Educational Resources Information Center

    Campillo Sainz, Carlos; Alvarez, Tostado, Juan

    This document is an English-language abstract (approximately 1,500 words) of a survey of Mexican medical education needs for the future. To plan for these needs, SISEM of UNAM was formed with the objectives of carrying out and promoting investigations in the different areas of medical education. It also wants to distribute the information…

  9. The Effect of Direct and Indirect Corrective Feedback on Students' Spelling Errors (El efecto de la retroalimentación directa e indirecta sobre los errores de ortografía de los estudiantes)

    ERIC Educational Resources Information Center

    Baleghizadeh, Sasan; Dadashi, Mehdi

    2011-01-01

    The study presented here is an attempt to examine the role of indirect feedback in promoting junior high school students' spelling accuracy in English. It compares the effect of direct feedback with indirect feedback on students' written work dictated by their teacher from their textbooks. Two classes were selected from the Zanjanrood…

  10. Memorias Conferencia Internacional IEEE Mexico 1971, Sobre Sistemas, Redes Y Computadoras. Volumen I and Volumen II. (Proceedings of International Conference of IEEE Concerning Systems, Networks, and Computers. Volume I and Volume II.

    ERIC Educational Resources Information Center

    Concheiro, A. Alonso, Ed.; And Others

    The following papers in English from this international conference may be of particular interest to those in the field of education. T. Nakahara, A. Tsukamota, and M. Matsumoto describe a computer-aided design technique for an economical urban cable television system. W. D. Wasson and R. K. Chitkara outline a recognition scheme based on analysis…

  11. Developing Mathematical Resilience: Students' Voice about the Use of ICT in Classroom (El desarrollo de la capacidad de resiliencia matemática: La voz de los estudiantes sobre el uso de las TIC en la aula)

    ERIC Educational Resources Information Center

    Mota, Ana Isabel; Oliveira, Hélia; Henriques, Ana

    2016-01-01

    Introduction: Mathematical resilience is assumed as one of the most important areas in school context and whose focus should be given priority, due to the distress exhibited by students when learning and understanding basic knowledge in mathematics year after year. The main goal of this research was to study how students attending middle schools…

  12. Fortalecete! Pensamientos e ideas sobre el desarrollo de curriculo para maestras de educacion basica en espanol ("Get Energized! Thoughts and Ideas on Curriculum Development for Spanish Basic Education Teachers").

    ERIC Educational Resources Information Center

    Holyoke JUNTOS Adult Basic Education Collaborative, MA.

    This booklet outlines approaches to adult basic education Spanish literacy. It includes the following: explanatory note for English (non-Spanish) readers; general goals of a Spanish language literacy (SLL) program in Holyoke, Massachusetts; checklists; learning objectives for reading and writing; SLL lesson plan guide; outline for SLL curriculum…

  13. Exploring Authorship Development among Mexican EFL Teacher-Researchers (Exploración sobre el desarrollo de la autoría en los profesores-investigadores de inglés como lengua extranjera)

    ERIC Educational Resources Information Center

    Trujeque Moreno, Eva Estefania; Encinas Prudencio, Fátima; Thomas-Ruzic, Maria

    2015-01-01

    This article presents a multi-theoretical model to address processes of "authorship development" in the English as a foreign language teaching profession. Working within a sociocultural perspective of second-language teacher education, the authors examined six experienced nonnative English-speaking teacher-researchers. Perceptions of…

  14. Western Hemisphere Conference on Persons with Disabilities. Conference Proceedings (Washington, D.C., March 14-18, 1993) = Conferencia Hemisferica Occidental sobre Personas con Discapacidades. Actas de la Conferencia. (Washington, D.C., 14 al 18 de Marzo de 1993).

    ERIC Educational Resources Information Center

    Kelley, Jerry D., Ed.; And Others

    This document presents the proceedings of a conference which brought together delegates and First Ladies representing western hemisphere nations to address needs and issues affecting people with disabilities in the Americas. It presents the texts of two keynote addresses: "Small Triumphs, Big Victories: A Global View of Persons with Disabilities,"…

  15. Aspectos de biología y tablas de vida de Cephalonomia stephanoderis y Prorops nasuta (Himenoptera: Bethilidae) sobre su hospedero la broca del café criada en la dieta artificial Cenibroca modificada.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological aspects and demographic parameters of the African bethylid wasps Cephalonamia stephanoderis Betrem and Prorops nasuta Waterson (Hymenopterans: Bethylidae) were investigated using diet-reared hosts of Hypothenemus hampei Ferrari (Coleoptera: Scolytidae). The life cycle (28.40 ± SE 0.486 a...

  16. Educacion, Salud y Bienestar para el Nino Preescolar y la Familia (7 de Enero--29 de Febrero de 1996). Informe Curso sobre (Education, Health and Welfare for Small Children. January 7 - February 29, 1996. Report of a Course.)

    ERIC Educational Resources Information Center

    Golda Meir Mount Carmel International Training Centre, Haifa (Israel).

    This Spanish-language report (with an English summary) describes a course on interagency cooperation held at the Golda Meir Mount Carmel International Training Center in Haifa, Israel. The course, with 30 Central and South American participants, discusses the necessity of pooling resources and sharing responsibility among institutions in various…

  17. Percepciones de los estudiantes de education en Venezuela sobre su preparacion e intervencion en violencia domestica. [Perceptions of Education Students in Venezuela about Their Preparation and Intervention in Domestic Violence].

    ERIC Educational Resources Information Center

    McArthur, Anna P.; Cellitti, Anarella; Perez de Linares, Sonia

    1999-01-01

    This study investigated Venezuelan university students' perceptions regarding domestic violence and possible encounters with domestic violence in programs for young children. Students indicated that they expected to encounter only those situations they were prepared to confront, indicating needs for curriculum changes in teacher-training programs.…

  18. The Use of Blogs in English Language Learning: A Study of Student Perceptions (El uso de bitácoras o "blogs" en el aprendizaje del idioma inglés: un estudio sobre las percepciones del estudiante)

    ERIC Educational Resources Information Center

    Ahluwalia, Gurleen; Gupta, Deepti; Aggarwal, Deepak

    2011-01-01

    In this article we present an investigation that focused on the students' perception of using Blogs as a means to supplement in-class language learning activities. Blogs are easy to manage and enable students to publish their work in a chronological manner. They help students to engage in online exchanges and promote learner autonomy. This…

  19. Reaching Higher. A Parent's Guide to the Washington Assessment of Learning. Revised = Para llegar mas arriba. Una guia para padres sobre la evaluacion del aprendizaje de los estudiantes del estado de Washington (Washington Assessment of Student Learning). Revisado.

    ERIC Educational Resources Information Center

    Washington Office of the State Superintendent of Public Instruction, Olympia.

    This guide in English and Spanish is designed to answer questions parents may have about the Washington Assessment of Student Learning (WASL), including how it will help improve their children's education, how it is scored, and how to use the information it provides. In Washington, clear educational goals for subject content, thinking skills, and…

  20. Role of Systematic Formative Assessment on Students' Views of Their Learning (El papel de la evaluación formativa en las percepciones de los estudiantes sobre su aprendizaje)

    ERIC Educational Resources Information Center

    Areiza Restrepo, Hugo Nelson

    2013-01-01

    This article presents a partial report of a small qualitative research study that explored the students' views of their learning during and after the implementation of formative procedures such as self-assessment, feedback, and conferences. The article also includes their perceptions about this implementation. The research was carried out with a…

  1. Essays on Eclipses, Transits and Occultations as Teaching Tools in the Introductory Astronomy College Course. (Spanish Title: Ensayos sobre Eclipses, Tránsitos y Ocultaciones Como Herramientas de Enseñanza en el Curso Universitario Introductorio a la Astronomía.) Ensaios sobre Eclipses, Trânsitos e Ocultações Como Ferramentas de Ensino em um Curso Universitário Introdutório de Astromomia

    NASA Astrophysics Data System (ADS)

    Dcruz, Noella L.

    2014-07-01

    We occasionally include projects in our learner-centered introductory astronomy college course to enable non-science major students explore some astronomical concepts in more detail than otherwise. Such projects also highlight ongoing or upcoming astronomical events. We hope that students will feel more interested in astronomy through projects tied to astronomical events. In Spring 2012, we offered short essays focused on eclipses, transits and occultations to promote the rare transit of Venus that occurred on June 5th, 2012. We asked students to write two short essays from three that were offered. The essays contained descriptive and conceptual parts. They were meant to serve as teaching tools. 62% of 106 essays from 55 students earned A, B or C grades. 21% of 47 feedback survey respondents felt the essays increased their interest in astronomy. 49% of respondents felt that the essays were not educationally beneficial and should not be offered again. The most common written response to our survey indicated that students need more guidance and better preparation in writing successful essays. Since students found the conceptual parts of the essays difficult, in the future we will provide relevant activities prior to essay deadlines to help students create successful essays. Ocasionalmente, incluimos proyectos en nuestro curso de introducción a la astronomía universitario centrado en el alumno para permitir que los estudiantes de carreras no científicas exploren algunos conceptos astronómicos en más detalle que lo habitual. Estos proyectos también ponen en relevancia eventos astronómicos en curso o futuros. Esperamos que los estudiantes se sientan más interesados en la astronomía a través de proyectos vinculados a eventos astronómicos. En el período de primavera de 2012 (EUA), propusimos breves ensayos centrados en los eclipses, tránsitos y ocultaciones para promover el raro tránsito de Venus que se produjo el 5 de junio de 2012. Le pedimos a los estudiantes que escribieran dos ensayos cortos de tres que se proponían. Los ensayos contenían partes descriptivas y conceptuales. Los mismos estaban destinados a servir como herramientas de enseñanza. 62% de los 106 ensayos de 55 estudiantes obtuvo grados A, B o C. 21% de los 47 encuestados que respondieron al cuestionario posterior consideró que los ensayos aumentaron su interés por la astronomía. 49% de los encuestados consideró que los ensayos no eran educacionalmente útiles y que no deben ser propuestos de nuevo. Las respuestas escritas más comunes a nuestra encuesta indicaran que los estudiantes necesitan más orientación y una mejor preparación en la redacción de ensayos exitosos. Dado que los estudiantes encontraron las piezas conceptuales de los ensayos difíciles, en el futuro vamos a ofrecer actividades pertinentes antes de los plazos de redacción para ayudar a los estudiantes a crear ensayos de mayor calidad. Nós ocasionalmente incluímos projetos em nosso curso universitário introdutório centrado no aluno para permitir aos estudantes que pertencem às carreiras não científicas explorar alguns conceitos astronômicos em mais detalhes do que o normal. Tais projetos também enfatizam eventos astronômicos em curso ou futuros. Esperamos que os alunos se sintam mais interessados na astronomia através de projetos ligados a eventos astronômicos. No termo de Primavera de 2012 (EUA), propomos ensaios curtos focados em eclipses, trânsitos e ocultações para promover o raro trânsito de Vênus que ocorreu no dia 5 de junho de 2012. Pedimos aos alunos que escrevessem dois ensaios curtos dentre três que foram propostos. Os ensaios continham partes descritivas e conceituais. Eles foram feitos para servir como ferramentas de ensino. 62% de 106 ensaios de 55 alunos ganhou graus A, B ou C. 21% dos 47 entrevistados que responderam ao levantamento posterior sentiu que os ensaios aumentaram seu interesse na astronomia. 49% dos inquiridos consideraram que os ensaios não eram benéficos para a educação e que não devem ser propostos novamente. As resp

  2. Providing Meaningful Learning for Students of the Sixth Grade of Middle School: a Study on the Moon Phases. (Breton Title: Propiciando Aprendizagem Significativa Para Alunos do Sexto Ano do Ensino Fundamental: um Estudo sobre as Fases da Lua.) Propiciando el Aprendizaje Significativo Para Alumnos del Sexto Nivel de la Educación General Básica: un Estudio sobre Las Fases de la Luna

    NASA Astrophysics Data System (ADS)

    Darroz, Luiz Marcelo; Samudio Pérez, Carlos Ariel; da Rosa, Cleci Werner; Heineck, Renato

    2012-07-01

    We relate in this article a didactic experience studying the moon phases with a group of middle school students of a private school of the municipality of Passo Fundo, RS. Based on David Ausubel's Meaningful Learning Theory, we have sought to develop a proposal following a didactic model which simulates the phases of the Moon, as based on the previous conceptions of the students. The signs of learning were evidenced by means of memory registries of the activity. From the obtained results we believe that the proposal achieved its goals, since the students were able to identify, differentiate and transfer the phenomenon of the moon phases to new contexts. Thus, it is concluded that a methodology focused on a meaningful content for the students is fundamental to the construction and genuine grasping of what is being learned. Neste artigo, relata-se uma experiência didática de estudo das fases da Lua com uma turma do 6° ano do Ensino Fundamental, de uma escola privada do município de Passo Fundo, RS. Tendo como fundamentação teórica a Teoria da Aprendizagem Significativa de David Ausubel, buscou-se desenvolver a proposta a partir de um modelo didático que simula as fases da Lua e com base nas concepções prévias dos estudantes. Os indícios da aprendizagem foram constatados através de registros de memórias da atividade. Pelos resultados apresentados, acredita-se que a proposta alcançou seus objetivos, uma vez que os estudantes conseguiram identificar, diferenciar e transferir o fenômeno das fases da Lua para novos contextos. Assim, conclui-se que uma metodologia com enfoque em um conteúdo significativo ao estudante é fundamental para a construção e compreensão genuína do que está sendo aprendido. En este artículo se relata una experiencia didáctica de estudio de las fases de la Luna con una clase de 6º año de la educación general básica de una escuela privada del municipio de Passo Fundo, RS. Teniendo como fundamentación teórica la Teoría del Aprendizaje Significativo de David Ausubel, se buscó desenvolver la propuesta a partir de un modelo didáctico que simula las Fases de la Luna, usando como base las concepciones previas de los estudiantes. Los indicios del aprendizaje fueron verificados a través de registros de memorias de la actividad. Por los resultados obtenidos creemos que la propuesta alcanzó sus objetivos, una vez que los estudiantes consiguieron identificar y transferir el fenómeno de las fases de la Luna para nuevos contextos. Así, se concluye que una metodología con enfoque en un contenido significativo para el estudiante es fundamental para la construcción y comprensión genuina de lo que está siendo aprendido.

  3. Ash wettability conditions splash erosion in the postfire

    NASA Astrophysics Data System (ADS)

    Gordillo-Rivero, Ángel J.; de Celis, Reyes; García-Moreno, Jorge; Jiménez-Compán, Elizabeth; Alanís, Nancy; Cerdà, Artemi; Pereira, Paulo; Zavala, Lorena M.; Jordán, Antonio

    2015-04-01

    ; Neuenschwander LF.(Eds.), Management and productivity of western-montane forest soils. General Technical Report INT-280. Intermountain Forest and Range Experimental Station, United States Department of Agriculture, Forest Service. Ogden, UT. DeBano LF. 2000. Water repellency in soils: a historical overview. Journal of Hydrology 231-232, 4-32. Doerr SH, Shakesby RA, Walsh RPD. 2000. Soil water repellency: its causes, characteristics and hydro-geomorphological significance. Earth-Science Reviews 51, 33-65. Larsen I, MacDonald LH, Brown E, Rough D, Welsh MJ, Pietraszek JH, Libohava Z, Benavides-Solorio JD, Schaffrath K. 2009. Causes of post-fire runoff and erosion: water repellency, cover or soil heating?. Soil Science Society of America Journal 73, 1393-1407. Mataix-Solera J, Guerrero C. 2007. Efecto de los incendios forestales sobre las propiedades edáficas. In: J. Mataix-Solera (Ed.) Incendios Forestales, Suelos y Erosión Hídrica. Caja Mediterráneo CENACAM Font Roja-Alcoi. Alicante. Pp.: 5-40. Mataix-Solera J, Guerrero C, Arcenegui V, Bárcenas G, Zornoza R, Pérez-Bejarano A, Bodí MB, Mataix-Beneyto J, Gómez I, García-Orenes F, Navarro-Pedreño J, Jordán MM, Cerdà A, Doerr SH, Úbeda X, Outeiro L, Jordán A, Zavala LM. 2009. Los incendios forestales y el suelo: un resumen de la investigación realizada por el Grupo de Edafología Ambiental de la UMH en colaboración con otros grupos. In: Cerdà A, Mataix-Solera J. (Eds.). El efecto de los incendios forestales sobre los suelos en España. El estado de la cuestión visto por los científicos españoles. Universitat de Valencia. Valencia. Pp.: 185-218. Mataix-Solera J, Cerdà A, Arcenegui V, Jordán A, Zavala LM. 2011. Fire efects on soil aggregation: a review. Earth-Science Reviews 109, 44-60 Neary DG, Klopatek CC, DeBano LF, Ffolliott PF. 1999. Fire effects on belowground sustainability: a review and synthesis. Forest Ecology and Management 122, 51-71. Pausas JG, Verdú M. 2005. Plant persistence traits in fire

  4. Prevención del cáncer de cavidad oral y orofaringe (PDQ®)—Versión para pacientes

    Cancer.gov

    Sumario de información revisada por expertos sobre factores que pueden influir en el riesgo de presentar cáncer de labio, cavidad oral y orofaringe, y sobre las investigaciones dirigidas a prevenir esta enfermedad.

  5. Upper Extremity Radiography

    MedlinePlus

    ... los anillos, pulseras y se acueste sobre la mesa de rayos X relojes, para que las áreas ... alhajas puedan radiografiarse. Si el brazo sobre la mesa. Se colocarán no puede sacarse un anillo porque ...

  6. 48 CFR 252.229-7005 - Tax exemptions (Spain).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Transfer Tax). (4) Impuesto Sobre el Lujo (Luxury Tax). (5) Actos Juridocos Documentados (Legal Official Transactions). (6) Impuesto Sobre el Trafico de Empresas (Business Trade Tax). (7) Impuestos Especiales de Fabricacion (Special Products Tax). (8) Impuesto Sobre el Petroleo y Derivados (Tax on Petroleum and its...

  7. Té y prevencìón de cáncer

    Cancer.gov

    Hoja informativa que resume los resultados de estudios realizados sobre el té y la prevención del cáncer. Incluye información sobre los ingredientes del té y las consideraciones de seguridad sobre el consumo de esta bebida.

  8. Biochar application to temperate soils - effects on soil fertility and crop yield

    NASA Astrophysics Data System (ADS)

    Kloss, S.; Zehetner, F.; Feichtmair, S.; Wimmer, B.; Zechmeister-Boltenstern, S.; Kitzler, B.; Watzinger, A.; Soja, G.

    2012-04-01

    Biochar (BC) application to soil as a potential soil amendment is currently intensively explored. Depending on feedstock and highest treatment temperature (HTT), BC application to soil may contribute to the soil nutrient status by directly adding nutrients to the soil as well as by increasing pH, cation exchange and water holding capacity. These parameters are known to play an important role in the soil nutrient status and nutrient availability. A positive effect on plant growth after BC application to tropical soils has been observed repeatedly; however, the effect of BC application to soils in temperate climate regions is much less explored. We investigated the effect of BC to temperate soils and crop yield using a randomized pot experiment in a greenhouse with three agricultural soils (Planosol, Cambisol, Chernozem) and four BC types (from straw, mixed woodchips and vineyard pruning, all pyrolyzed at 525°C). In order to analyze the effect of pyrolysis temperature, we additionally applied vineyard pruning BC pyrolyzed at 400°C. Selected treatments were planted with mustard (Sinapis alba L.), followed by barley (Hordeum vulgare). Soil sampling was carried out after barley harvest. Investigated soil parameters included pH, electrical conductivity (EC), C/N ratio, cation exchange capacity (CEC), CAL-extractable P and K, EDTA extractable Cu, Fe, Mn, Zn as well as nitrogen supplying potential (NSP). Biomass production of the two crops was determined as well as its elemental composition. Biochar application (3% wood-based BC) caused a considerable pH increase for the acidic Planosol. The effect of BC application on CEC was dependent on the original status of the soil, notably soil pH and texture. 3 % BC application (wood) decreased CEC by 3.5 % and 10 % for the Chernozem and Cambisol, respectively, but increased CEC by 35 % for the acidic, sandy Planosol, which may be due to the strong liming effect found for the Planosol. BC application significantly raised CAL

  9. Stable isotope signatures in bulk samples from two soils with contrasting characteristics. What do they tell about ongoing pedogenic processes?

    NASA Astrophysics Data System (ADS)

    Jiménez-Morillo, Nicasio T.; dos Anjos Leal, Otávio; Knicker, Heike; Pinheiro Dick, Deborah; González-Vila, Francisco J.; González-Pérez, José A.

    2014-05-01

    Isotopic ratio mass spectrometry (IRMS) has been proven as a promising tool for the monitoring of biogeochemical processes in soil. In this work, stable isotope signatures of light elements δ15N, δ13C, δ18O and δD were determined for two soils with contrasting characteristics in terms of climate, vegetation, land use and management. The studied soils were a Cambisol from a subtropical area (Paraná region, South Brazil) and an Arenosol from a Mediterranean climate (Andalusia, South Spain). A Flash 2000 HT (N, C, S, H and O) elemental analyzer (Thermo Scientific) coupled to a Delta V Advantage IRMS (Thermo Scientific) was used. Isotopic ratios are reported as parts per thousand (o ) deviations from appropriate standards recognized by the international atomic energy agency (IAEA). In a first approach we took advantage of the well-known different δ13C signature between plants using either the C4 or C3 carbon fixation pathway (O'Leary, 1981). The Arenosol (Spain) revealed a δ13C signature which is clearly in the range of C3 plants (-26 to -30 o ). Different plant canopies (tree, shrubs or ferns) caused only slight variations δ13C (STD= 0.98). In contrast, the Cambisol (Brazil) showed less depletion of the heavier carbon isotope corresponding to C4 predominant vegetation. In addition an increase from -19 o in the soil surface (0 - 5 cm) to -16 o in the subsoil (20 - 30 cm) was observed in line with a recent (2 years old) shift of the land use from the predominant C4 grassland to eucalypt (C3) cultivation. Crossplots of δ15N vs. δ18O may provide information about nitrate (NO3-) sources and N cycling (Kendall, 1998). In the Mediterranean Arenosol this signal (δ18O = 30o δ15N = 2o ) was found compatible with a predominant nitrate atmospheric deposition, whereas the signal in the Brazilian Cambisol pointed to the use of a mineral N fertilization with signs of denitrification processes (δ18O = 13o δ15N = 9o ). No conclusive results could be obtained from the

  10. Soil and substrate morphology as witnesses of present and former agricultural landscape management

    NASA Astrophysics Data System (ADS)

    Chartin, C.; Salvador-Blanes, S.; Hinschberger, F.; Bourennane, H.; Macaire, J.-J.

    2009-04-01

    Water and tillage erosion, combined with the effect of successive regrouping of the land campaigns, have sensibly modified the morphology of cultivated hillslopes. Nowadays, we can still observe over cultivated landscapes various anthropogenic structures (e.g. lynchets) that correspond to former and/or present field limits. The aim of this work is to spatially characterise the geometry of these various structures, and to assess their relation with soil variability. The 10 ha studied site corresponds to an hillslope located in a small calcareous watershed near Tours in the Parisian Basin (France). Soils are mainly Cambisols (calcaric), Epileptic cambisols (calcaric) and Colluvic cambisols. This watershed is characterised by the presence of many soil accumulation structures and has been submitted to an important regrouping of the lands since the 1960's. The existing structures were accurately located and defined through a topographical analysis (slope, profile curvature...), and then related to past and present field limits using aerial photographies and cadastral maps. Two main morphological structures, deeply marked in the topography, are identified. The most remarkable type corresponds to well developed lynchets located at the lower part of field limits. Secondary structures, less marked than lynchets, are linked to field limits which existed at least since 1836, but that disappeared from the 1960's. These secondary structures look like longitudinal bulges placed perpendicularly to the direction of the main slope. A soil survey on these two geomorphic structure types has been performed in order to determine their specific geometry. Lynchets are characterised by a large increase in the thickness of soils: from 35 cm at 24 m upslope to more than 120 cm on its top. But, in some cases, the elevation study shows a topographical discontinuity between the top of the accumulation and the field or road below, discontinuity that is more important than the maximum soil

  11. Uncertainties and Solutions Related to Use of WRB (2007) in the Boreo-nemoral zone, Case of Latvia

    NASA Astrophysics Data System (ADS)

    Kasparinskis, Raimonds; Nikodemus, Olgerts; Rolavs, Nauris

    2014-05-01

    Relatively high diversity of soils groups according to the WRB (2007) classification is observed in forest ecosystems in the boreo-nemoral zone in Latvia. This is due to the geological genesis of area and environmental conditions (Kasparinskis, Nikodemus, 2012), as well as historical land use and management (Nikodemus et al., 2013). Due to the relatively young soils, Albic, Spodic and Cambic horizons are relatively weakly expressed in many cases. Relatively well developed Albic horizons occur in sandy forest soils, but unusually well expressed Spodic features are observed. In some cases there is a Cambic horizon, however location of Cambisols in the WRB (2007) soil classification sequence does not provide an opportunity to classify these soils as Cambisols, but they are classified as Arenosols. This sequence does not reflect the logical sheme of soil development, and therefore raises the question about location of Podzols, Arenosols and Cambisols in the sequence of WRB (2007) soil classification. Soils with two parent materials (abrupt textural change) are relatively common in Latvia, where conceptually on the small scale mapping results in classification as the soil group Planosols, but in many cases there is occurrence of Fluvic materials, as parent material in the upper part of the soil profile is formed by Baltic Ice lake sandy sediments - this leads to question about the location of Fluvisols and Planosols in the sequence of the WRB (2007) soil classification. Soil research has found cases, where a relatively well developed Spodic horizon was established as the result of ground water table depth in areas of abrupt textural change. In this case the profile corresponds to the soil group of Podzols, however in some cases - Gleysols not Planosols due to a high ground water table. Therefore there is a need for discussion also about the location of Podzols and Planosols in the sequence of the WRB (2007) soil classification. The above mentioned questions raise

  12. About soil cover heterogeneity of agricultural research stations' experimental fields

    NASA Astrophysics Data System (ADS)

    Rannik, Kaire; Kõlli, Raimo; Kukk, Liia

    2013-04-01

    Depending on local pedo-ecological conditions (topography, (geo) diversity of soil parent material, meteorological conditions) the patterns of soil cover and plant cover determined by soils are very diverse. Formed in the course of soil-plant mutual relationship, the natural ecosystems are always influenced to certain extent by the other local soil forming conditions or they are site specific. The agricultural land use or the formation of agro-ecosystems depends foremost on the suitability of soils for the cultivation of feed and food crops. As a rule, the most fertile or the best soils of the area, which do not present any or present as little as possible constraints for agricultural land use, are selected for this purpose. Compared with conventional field soils, the requirements for the experimental fields' soil cover quality are much higher. Experimental area soils and soil cover composition should correspond to local pedo-ecological conditions and, in addition to that, represent the soil types dominating in the region, whereas the fields should be as homogeneous as possible. The soil cover heterogeneity of seven arable land blocks of three research stations (Jõgeva, Kuusiku and Olustvere) was studied 1) by examining the large scale (1:10 000) digital soil map (available via the internet), and 2) by field researches using the transect method. The stages of soils litho-genetic and moisture heterogeneities were estimated by using the Estonian normal soils matrix, however, the heterogeneity of top- and subsoil texture by using the soil texture matrix. The quality and variability of experimental fields' soils humus status, was studied more thoroughly from the aspect of humus concentration (g kg-1), humus cover thickness (cm) and humus stocks (Mg ha-1). The soil cover of Jõgeva experimental area, which presents an accumulative drumlin landscape (formed during the last glacial period), consist from loamy Luvisols and associated to this Cambisols. In Kuusiku area

  13. Within-field and regional-scale accuracies of topsoil organic carbon content prediction from an airborne visible near-infrared hyperspectral image combined with synchronous field spectra for temperate croplands

    NASA Astrophysics Data System (ADS)

    Vaudour, Emmanuelle; Gilliot, Jean-Marc; Bel, Liliane; Lefevre, Josias; Chehdi, Kacem

    2016-04-01

    This study was carried out in the framework of the TOSCA-PLEIADES-CO of the French Space Agency and benefited data from the earlier PROSTOCK-Gessol3 project supported by the French Environment and Energy Management Agency (ADEME). It aimed at identifying the potential of airborne hyperspectral visible near-infrared AISA-Eagle data for predicting the topsoil organic carbon (SOC) content of bare cultivated soils over a large peri-urban area (221 km2) with intensive annual crop cultivation and both contrasted soils and SOC contents, located in the western region of Paris, France. Soils comprise hortic or glossic luvisols, calcaric, rendzic cambisols and colluvic cambisols. Airborne AISA-Eagle images (400-1000 nm, 126 bands) with 1 m-resolution were acquired on 17 April 2013 over 13 tracks. Tracks were atmospherically corrected then mosaicked at a 2 m-resolution using a set of 24 synchronous field spectra of bare soils, black and white targets and impervious surfaces. The land use identification system layer (RPG) of 2012 was used to mask non-agricultural areas, then calculation and thresholding of NDVI from an atmospherically corrected SPOT4 image acquired the same day enabled to map agricultural fields with bare soil. A total of 101 sites, which were sampled either at the regional scale or within one field, were identified as bare by means of this map. Predictions were made from the mosaic AISA spectra which were related to SOC contents by means of partial least squares regression (PLSR). Regression robustness was evaluated through a series of 1000 bootstrap data sets of calibration-validation samples, considering those 75 sites outside cloud shadows only, and different sampling strategies for selecting calibration samples. Validation root-mean-square errors (RMSE) were comprised between 3.73 and 4.49 g. Kg-1 and were ~4 g. Kg-1 in median. The most performing models in terms of coefficient of determination (R²) and Residual Prediction Deviation (RPD) values were the

  14. Comparison of PLSR and SVM methods for predicting the organic carbon content using VNIR DRS at five locations with different soil types

    NASA Astrophysics Data System (ADS)

    Klement, Ales; Kodesova, Radka; Vasat, Radim; Fer, Miroslav; Brodsky, Lukas; Jaksik, Ondrej

    2015-04-01

    Visible and near-infrared diffuse reflectance spectroscopy (VNIR DRS) is cost- and time-effective and environmentally friendly techniques method used for prediction of soil properties. There are many studies dealing with this approach for particular conditions (single locality, different area size, etc.). This study was therefore focused on evaluating the suitability of VNIR DRS (400 - 2500 nm) for predicting organic carbon content, using samples collected at 5 agricultural lands from the municipalities of Brumovice (107 samples), Hostoun (58 samples), Sedlcany (78 samples), Vidim (86 samples) and Zelezna (69 samples). In Brumovice original soil type was Haplic Chernozem on loess, which was due to erosion changed into Regosol (steep parts) and Colluvial soil (base slope and the tributary valley). A similar process has been observed at other four locations Hostoun, Sedlcany, Vidim and Zelezna where the original soil types were Calcaric Leptosol, Haplic Cambisol on gneiss, Haplic Luvisol on loess and Haplic Cambisol on shales, respectively. Samples were taken from the topsoil within regular grid covering studied areas. Variable approaches may be applied to relate reflectance spectral data to particular soil property. Here were used Partial Least Square Regression (PLSR) and Support Vector Machine (SVM) with cross-validation to relate organic carbon content data to the reflectance spectral data by applying different preprocessing strategies. According to the criteria of minimal Root Mean Square Error of Prediction of Cross Validation (RMSEPcv) and maximal coefficient of determination (R2cv), the PLSR and SVMR models with raw spectra, the first and second derivative pretreatment provided the most accurate prediction for the organic carbon content from Brumovice (SVM, 1st. derivative, R2cv = 0.87, RMSEPcv = 0.11) and decreased as follows: Hostoun (PLSR, 2nd. derivative, R2cv = 0.69, RMSEPcv = 0.11), Sedlcany (SVM, 2nd. derivative, R2cv = 0.66, RMSEPcv = 0.17), Zelezna

  15. Regional prediction of soil organic carbon content over temperate croplands using visible near-infrared airborne hyperspectral imagery and synchronous field spectra

    NASA Astrophysics Data System (ADS)

    Vaudour, E.; Gilliot, J. M.; Bel, L.; Lefevre, J.; Chehdi, K.

    2016-07-01

    This study aimed at identifying the potential of Vis-NIR airborne hyperspectral AISA-Eagle data for predicting the topsoil organic carbon (SOC) content of bare cultivated soils over a large peri-urban area (221 km2) with both contrasted soils and SOC contents, located in the western region of Paris, France. Soil types comprised haplic luvisols, calcaric cambisols and colluvic cambisols. Airborne AISA-Eagle data (400-1000 nm, 126 bands) with 1 m-resolution were acquired on 17 April 2013 over 13 tracks. Tracks were atmospherically corrected then mosaicked at a 2 m-resolution using a set of 24 synchronous field spectra of bare soils, black and white targets and impervious surfaces. The land use identification system layer (RPG) of 2012 was used to mask non-agricultural areas, then calculation and thresholding of NDVI from an atmospherically corrected SPOT image acquired the same day enabled to map agricultural fields with bare soil. A total of 101 sites sampled either in 2013 or in the 3 previous years and in 2015 were identified as bare by means of this map. Predictions were made from the mosaic AISA spectra which were related to topsoil SOC contents by means of partial least squares regression (PLSR). Regression robustness was evaluated through a series of 1000 bootstrap data sets of calibration-validation samples, considering 74 sites outside cloud shadows only, and different sampling strategies for selecting calibration samples. Validation root-mean-square errors (RMSE) were comprised between 3.73 and 4.49 g Kg-1 and were ∼4 g Kg-1 in median. The most performing models in terms of coefficient of determination (R2) and Residual Prediction Deviation (RPD) values were the calibration models derived either from Kennard-Stone or conditioned Latin Hypercube sampling on smoothed spectra. The most generalizable model leading to lowest RMSE value of 3.73 g Kg-1 at the regional scale and 1.44 g Kg-1 at the within-field scale and low bias was the cross-validated leave

  16. Organic matter composition of matrix-macropore interfaces in structured subsoils

    NASA Astrophysics Data System (ADS)

    Leue, M.; Gerke, H. H.; Ellerbrock, R. H.

    2012-04-01

    In structured soils, the interaction of percolating water and reactive solutes with the soil matrix is mostly restricted to surfaces of preferential flow paths. Surfaces of flow paths that are formed by cracks, decayed root channels or worm burrows are often covered by clay-organic coatings (i.e., cutanes), in which the outermost layer is mainly organic matter (OM). The composition of OM finally controls wettability, sorption, and transfer properties and thus may influence the water movement in structured soils. However, the in-situ local distribution of OM properties along such surfaces is largely unknown to date because experimental techniques to study the relatively thin and vulnerable coatings at intact structure surfaces were not available. The objective of this study was to analyze the local mm-scale OM distribution and composition at preferential flow paths of structured subsoils. We took samples from different soil types (Luvisol, Regosol, Stagnosol, Cambisol), of different geological provenance (till, loess, mudstone, limestone), and of different land use (arable, forest). The Fourier transformed infrared spectroscopy in diffuse reflectance mode (DRIFT) was used to determine spectral information in 1 mm steps along transects of 15 up to 65 mm length along the intact structural surfaces (cracks and biopores). The distribution of OM composition was characterized by evaluating the ratios of the absorption band intensities of the alkyl- (C-H-) and carbonyl (C=O-) functional groups (CH/CO), which represent a measure of the potential wettability of the OM of the surface. In general the CH/CO-ratios were higher for earthworm burrows and root channels as compared to crack surfaces and the soil matrix. Earthworm burrows of soils developed on loess (Haplic Luvisol) showed higher CH/CO-ratios than soils developed on till (Haplic Regosol, Albic Luvisol); the highest CH/CO-ratios occurred at worm burrows of both a Vertic Stagnosol and a Vertic Cambisol (mudstone

  17. Quantifying water and air redistribution in heterogeneous sand sample by neutron imaging

    NASA Astrophysics Data System (ADS)

    Šácha, Jan; Sobotková, Martina; Jelínková, Vladimíra; Sněhota, Michal; Vontobel, Peter; Hovind, Jan

    2014-05-01

    Significant temporal variation of quasi saturated hydraulic conductivity (Kqs) has been observed to date in number of infiltration experiments conducted mainly on heterogeneous soil of Cambisol. The change of quasi-saturated hydraulic conductivity cannot be precisely described by existing models. The Kqs variations has been recently attributed to a changing distribution of the entrapped air and water within the sample. It is expected that air is moved to the preferential pathway and acts as a barrier there. To support this assumption a ponded infiltration experiment was conducted on a soil sample packed into the quartz glass column of inner diameter of 34 mm. The sample composition represents simplified heterogeneity of the natural soil but also allow the easy quantitative water content determination in individual subdomains of the sample. The matrix formed by a fine sand was surrounded with regions of coarse sand representing preferential flow pathways. The Kqs was determined from the known hydraulic gradient and measured volume flux. The experiment was monitored by neutron radiography. Volume of water in the sample calculated from neutron projections matched very well with actually infiltrated volume in the sample during first 40 second after beginning of infiltration. From the acquired radiographic images the 3D tomography images were reconstructed to obtain the spatial distribution of the water content within the sample. Difference between water volume calculated from radiography and tomography images was no more than 5%. While the total amount of water determined by NR within the sample during the quasi steady state flow remains practically constant (27.9 cm3 at the beginning and 28.6 cm3 on the end of infiltration) the water content in the coarse fraction decreases (from 0.333 to 0.324) and the water content in the fine fraction increases (from 0.414 to 0.436) in 5 hours. Similarly to previous experiments performed on natural Cambisols, the results support

  18. Aggregate size distribution of the soil loss

    NASA Astrophysics Data System (ADS)

    Szabó, Judit Alexandra; Jakab, Gergely; Szabó, Boglárka; Józsa, Sándor; Szalai, Zoltán; Centeri, Csaba

    2016-04-01

    In agricultural areas the soil erosion and soil loss estimation is vital information in long-term planning. During the initial period of the erosion a part of the soil particles and aggregates get transportable and nutrients and organic matter could be transported due to the effect of water or wind. This preliminary phase was studied with laboratory-scale rainfall simulator. Developed surface crust and aggregate size composition of the runoff was examined in six different slope-roughness-moisture content combination of a Cambisol and a Regosol. The ratio of micro- and macro aggregates in the runoff indicate the stability of the aggregates and determine the transport capacity of the runoff. Both soil samples were taken from field where the water erosion is a potential hazard. During the experiment the whole amount of runoff and sediment was collected through sieve series to a bucket to separate the micro- and macro aggregates. In case of both samples the micro aggregates dominate in the runoff and the runoff rates are similar. Although the runoff of the Regosol - with dominant >1000μm macro aggregate content - contained almost nothing but <50μm sized micro aggregates. Meanwhile the runoff of the Cambisol - with more balanced micro and macro aggregate content - contained dominantly 50-250μm sized micro aggregates and in some case remarkable ratio 250-1000μm sized macro aggregates. This difference occurred because the samples are resistant against drop erosion differently. In case of both sample the selectivity of the erosion and substance matrix redistribution manifested in mineral crusts in the surface where the quartz deposited in place while the lighter organic matter transported with the sediment. The detachment of the aggregates and the redistribution of the particles highly effect on the aggregate composition of the runoff which is connected with the quality of the soil loss. So while the estimation of soil loss quantity is more or less is easy, measuring

  19. Regional prediction of soil organic carbon content over croplands using airborne hyperspectral data

    NASA Astrophysics Data System (ADS)

    Vaudour, Emmanuelle; Gilliot, Jean-Marc; Bel, Liliane; Lefebvre, Josias; Chehdi, Kacem

    2015-04-01

    This study was carried out in the framework of the Prostock-Gessol3 and the BASC-SOCSENSIT projects, dedicated to the spatial monitoring of the effects of exogenous organic matter land application on soil organic carbon storage. It aims at identifying the potential of airborne hyperspectral AISA-Eagle data for predicting the topsoil organic carbon (SOC) content of bare cultivated soils over a large peri-urban area (221 km2) with both contrasted soils and SOC contents, located in the western region of Paris, France. Soils comprise hortic or glossic luvisols, calcaric, rendzic cambisols and colluvic cambisols. Airborne AISA-Eagle data (400-1000 nm, 126 bands) with 1 m-resolution were acquired on 17 April 2013 over 13 tracks which were georeferenced. Tracks were atmospherically corrected using a set of 22 synchronous field spectra of both bare soils, black and white targets and impervious surfaces. Atmospherically corrected track tiles were mosaicked at a 2 m-resolution resulting in a 66 Gb image. A SPOT4 satellite image was acquired the same day in the framework of the SPOT4-Take Five program of the French Space Agency (CNES) which provided it with atmospheric correction. The land use identification system layer (RPG) of 2012 was used to mask non-agricultural areas, then NDVI calculation and thresholding enabled to map agricultural fields with bare soil. All 18 sampled sites known to be bare at this very date were correctly included in this map. A total of 85 sites sampled in 2013 or in the 3 previous years were identified as bare by means of this map. Predictions were made from the mosaic spectra which were related to topsoil SOC contents by means of partial least squares regression (PLSR). Regression robustness was evaluated through a series of 1000 bootstrap data sets of calibration-validation samples. The use of the total sample including 27 sites under cloud shadows led to non-significant results. Considering 43 sites outside cloud shadows only, median

  20. Effects of future climate change on grape and wine quality: a case study for the Aglianico grape, Campania. Italy.

    NASA Astrophysics Data System (ADS)

    Bonfante, Antonello; Gambuti, Angelita; Monaco, Eugenia; Langella, Giuliano; Manna, Piero; Orefice, Nadia; Albrizio, Rossella; Basile, Angelo; Terribile, Fabio

    2016-04-01

    Water deficits limit yields and this is one of the negative aspects of climate change. However, this applies particularly when emphasis is on biomass production (e.g. for crops like maize, wheat, etc.) but not for plants where quality, not quantity is most relevant. For example, water stress occurring during specific phenological phases of grapevine development is an important factor when producing good quality wines. It induces, for example, the production of anthocyanins and aroma precursors. Water stress due to future increases of temperature and decreases of rainfall due to climate change can, therefore, represent an opportunity to increase winegrowers' incomes. This study was carried out in Campania region (Southern Italy), an area well known for high quality wine production. Growth of the Aglianico grapevine cultivar, with a standard clone population on 1103 Paulsen rootstocks, was studied on two different types of soil: Calcisols and Cambisols occurring along a slope of 90 m length with 11% gradient. The agro-hydrological model SWAP was calibrated and applied to estimate soil-plant water status at the various crop phenological phases for three vintages (2011-2013). Then, the Crop water stress index (CWSI), as estimated by the model, was related to physiological measurements (e.g. leaf water potential), grape bunches measurements (e.g. sugar content) and wine quality (e.g. tannins). For both soils, the correlation between measurements and CWSI were high (e.g. -0.97** with sugar; 0.895* with anthocyanins in the skins). Next, the model was applied to future climate conditions (2021-2051) obtained from statistical downscaling of Global Circulation Models (AOGCM) in order to estimate the effect of the climate on CWSI and hence on vine quality. Results show that the effects of climate change on grape and wine quality are not expected to be significant for this particular grape variety when grown on these Calcisols and Cambisols. However, significant differences

  1. Mapping within-field variations of soil organic carbon content using UAV multispectral visible near-infrared images

    NASA Astrophysics Data System (ADS)

    Gilliot, Jean-Marc; Vaudour, Emmanuelle; Michelin, Joël

    2016-04-01

    This study was carried out in the framework of the PROSTOCK-Gessol3 project supported by the French Environment and Energy Management Agency (ADEME), the TOSCA-PLEIADES-CO project of the French Space Agency (CNES) and the SOERE PRO network working on environmental impacts of Organic Waste Products recycling on field crops at long time scale. The organic matter is an important soil fertility parameter and previous studies have shown the potential of spectral information measured in the laboratory or directly in the field using field spectro-radiometer or satellite imagery to predict the soil organic carbon (SOC) content. This work proposes a method for a spatial prediction of bare cultivated topsoil SOC content, from Unmanned Aerial Vehicle (UAV) multispectral imagery. An agricultural plot of 13 ha, located in the western region of Paris France, was analysed in April 2013, shortly before sowing while it was still bare soil. Soils comprised haplic luvisols, rendzic cambisols and calcaric or colluvic cambisols. The UAV platform used was a fixed wing provided by Airinov® flying at an altitude of 150m and was equipped with a four channels multispectral visible near-infrared camera MultiSPEC 4C® (550nm, 660nm, 735 nm and 790 nm). Twenty three ground control points (GCP) were sampled within the plot according to soils descriptions. GCP positions were determined with a centimetric DGPS. Different observations and measurements were made synchronously with the drone flight: soil surface description, spectral measurements (with ASD FieldSpec 3® spectroradiometer), roughness measurements by a photogrammetric method. Each of these locations was sampled for both soil standard physico-chemical analysis and soil water content. A Structure From Motion (SFM) processing was done from the UAV imagery to produce a 15 cm resolution multispectral mosaic using the Agisoft Photoscan® software. The SOC content was modelled by partial least squares regression (PLSR) between the

  2. Spatial variability of cv Tempranillo phenology within the Ribera del Duero DO (Spain) related to soil type and plot characteristics

    NASA Astrophysics Data System (ADS)

    Ramos, Maria C.; Jones, Gregory V.; Yuste, Jesús

    2014-05-01

    Vineyards in the Ribera del Duero area (Spain) date back to the roman time, with significant fluctuations throughout the centuries, reaching consolidation and stable production in the 10th and 11th centuries. The present Ribera del Duero Designation of Origen (DO) started in 1980 and has increased from less than 6,000 ha planted to more than 21,000 ha planted by 2010 and becoming one the top regions for wine production in Spain with success in the global wine market. Vineyards of Ribera del Duero are found along 115 km of the Duero River. Within this distance, differences in elevation and topography produce differences in climate, which provide the means by which a zonification for vineyard management can be assessed. In this work, the differences in phenological growth characteristics for the Tempranillo variety were analyzed within the Ribera del Duero DO and related to soil and plot characteristics. Phenology dates, referenced to different Baggiolini classification stages, were evaluated in 20 control plots distributed throughout the Ribera del Duero DO during the period 2004-2012. These years presented different climatic characteristics, which were analyzed from daily temperature and precipitation series recorded from 1980 to 2012 at five stations located along the Duero River. Most vineyards were cultivated under rainfed conditions. In order to evaluate the spatial variability in phenology, climate and soils, the plots were classified using a hierarchical cluster multivariate analysis. Parameters such as the elevation, the distance to river and the soil type were taken into account in the classification. According to the WRB classification (2006) the main soil types in the area are Calcaric Cambisols, Eutric Cambisols, Calcic Luvisol, Calcaric fluvisols, Eutric fluvisols and in less proportion Lithic Leptosols and Calcaric Rogosols. Four different groups were observed, with differences in elevation, distance to the Duero River and the soil type. The

  3. Analysis of the maximum discharge of karst springs

    NASA Astrophysics Data System (ADS)

    Bonacci, Ognjen

    2001-07-01

    ) la dimension limitée du conduit karstique, (2) l'écoulement en charge, (3) le débordement dans un autre bassin, (4) le débordement du réseau s'écoulant vers la source principale par des sources temporaires dans le même bassin, (5) le stockage d'eau dans la zone surmontant l'aquifère karstique ou la zone épikarstique du bassin, et (6) des facteurs tels que le climat, le sol et le couvert végétal, l'altitude et la géologie du bassin d'alimentation. Le phénomène de capacité limitée du débit maximal des sources karstiques n'est pas pris en compte dans la modélisation des processus de précipitation-ruissellement, ce qui est probablement une des principales raisons de l'actuelle médiocre qualité de la modélisation hydrologique du karst. Resumen. Se presenta un análisis de las condiciones que limitan la descarga de algunos manantiales kársticos. Un elevado número de los manantiales estudiados muestra que, bajo condiciones de precipitación extremadamente intensa, hay un valor máximo para la descarga de los manantiales principales de la cuenca, independientemente del tamaño de ésta y del volumen de precipitación. La modelación de la descarga de manantiales kársticos no es fácil de generalizar y esquematizar debido a la existencia de numerosas características que son inherentes a los sistemas kársticos de flujo. A partir del estudio detallado de los datos publicados sobre cuatro manantiales kársticos, se identificó las posibles causas de la existencia de un caudal máximo de descarga: (1) el tamaño limitado del conducto kárstico, (2) el caudal surgente, (3) la descarga a otras cuencas, (4) el desbordamiento del sistema de flujo principal hacia manantiales intermitentes dentro de la misma cuenca, (5) el almacenamiento de agua en la zona superior del acuífero kárstico o zona epikárstica de la cuenca, y (6) factores tales como el clima, suelo y cubierta vegetal, y la altitud y geología de la zona de captación. La limitación de la

  4. Groundwater evolution beneath Hat Yai, a rapidly developing city in Thailand

    NASA Astrophysics Data System (ADS)

    Lawrence, A. R.; Gooddy, D. C.; Kanatharana, P.; Meesilp, W.; Ramnarong, V.

    2000-09-01

    de l'aquifère plus profond, ce qui aura, à long terme, des implications sur la qualité de l'eau. Les résultats fournis par des forages carottés et des piézomètres peu profonds sont présentés. La combinaison entre une concentration élevée en matières organiques, provenant de la recharge par les eaux usées domestiques, et la faible profondeur de la nappe a produit des conditions fortement réductrices dans le niveau supérieur et une mobilisation de l'arsenic. Un modèle analytique simple montre que les échelles de temps pour la drainance vers le bas, à partir de la surface au travers de l'imperméable supérieur vers l'aquifère semi-captif, sont de l'ordre de quelques dizaines d'années. Resumen. Muchas ciudades en el sur y sudeste de Asia carecen de sistemas de saneamiento, por lo que las aguas residuales urbanas son a menudo vertidas bien directamente al suelo o bien a canales de aguas superficiales. Esta práctica puede provocar la contaminación difusa de las aguas subterráneas someras. En Hat Yai, al sur de Tailandia, la percolación de aguas residuales urbanas ha producido un deterioro substancial de la calidad del acuífero somero sobre el que se sitúa la ciudad. Por ello, la mayor parte del suministro de agua potable se obtiene a partir de aguas subterráneas de acuíferos semiconfinados más profundos, localizados entre 30 y 50 m bajo la superficie. No obstante, el goteo desde el acuífero freático constituye una fracción importante de la recarga al acuífero profundo, hecho que tiene implicaciones en lo que respecta a la calidad del agua a largo plazo. Se presentan en este artículo los resultados de testigos de sondeos y de multi-piezómetros someros. El alto contenido en materia orgánica de las aguas urbanas, unido a la cercanía del nivel freático, ha producido la movilización de arsénico al crearse condiciones altamente reductoras. Un modelo matemático sencillo indica que el tiempo de tránsito desde la superficie hasta el acu

  5. Scheme for development of monitoring networks for springs in Bavaria, Germany

    NASA Astrophysics Data System (ADS)

    Bender, Steffen; Einsiedl, Florian; Wohnlich, Stefan

    2001-03-01

    constituer un jeu de données de base pour guider la future surveillance. Une procédure de sélection a été développée autour de quatre paramètres: (1) les unités géologiques, comprenant les principaux aquifères, (2) le débit des sources, (3) l'occupation du sol dans le bassin, et (4) la dimension approximative du bassin d'alimentation souterrain. Toutefois, dans la phase initiale de l'étude, seuls les trois premiers paramètres ont été étudiés. Ces paramètres constituent une matrice d'évaluation de chaque région hydrogéologique de Bavière pour aider à la sélection de sources supplémentaires destinées au réseau de surveillance proposé. Resumen. La red de muestreo actual de aguas subterráneas en Bavaria (Alemania) está formada sobre todo por pozos, mientras que apenas hay unos pocos manantiales naturales. Los análisis incluyen, principalmente, los parámetros físico-químicos habituales. Con el objeto de desarrollar un plan de gestión de las aguas subterráneas en Bavaria a largo plazo, el Consejo del Estado para la Gestión del Agua pretende establecer una red de muestreo de manantiales diferenciada en las once regiones en que se divide el estado desde el punto de vista de las aguas subterráneas. Como primer paso, se determinaron los parámetros físico-químicos significativos que mostraban una fluctuación anual considerable (tras un muestreo de 1 a 3 años), con la finalidad de crear una base de datos elemental que canalizara los muestreos futuros. Se desarrolló un procedimiento de selección con base en cuatro parámetros: (1) unidades geológicas y acuíferos principales; (2) caudal del manantial; (3) uso del suelo dentro de la cuenca; y (4) tamaño aproximado de la zona de captación subterránea. Sin embargo, sólo se investigaron los tres primeros parámetros durante la fase inicial del estudio. Con ellos, se estableció una matriz para evaluar cada zona acuífera dentro de Bavaria y ayudar en la inclusión de otros manantiales en la

  6. Operational tools and applications of EO satellite data to retrieve surface fluxes in semi-arid countries

    NASA Astrophysics Data System (ADS)

    Tanguy, Maliko

    ítulo 4), se evalúa la fiabilidad de una nueva parametrización para estimar el flujo de calor en el suelo (G) con el fin de ser utilizado en métodos de estimación de la evapotranspiración (ET) usando datos de teledetección. La parametrización de G se optimiza usando datos de flujo de energía obtenido durante las campañas del proyecto AMMA, y muestra buenos resultados y una mejora de las estimaciones del flujo de calor sensible (H) y de ET cuando se utiliza conjuntamente con el método del triángulo (Jiang & Islam, 2001). En una segunda parte (Capítulo 5), el método del triángulo se compara con valores de ET estimado por un modelo de superficie terrestre (JULES). Se intenta calibrar JULES usando el método del triángulo mediante simulaciones de Monte Carlo, pero los dos métodos muestran resultados muy diferentes, indicando que se necesita tareas de comparación profundizadas para poder evaluar la eficacia de estos modelos (de superficie terrestre y basados en la teledetección) para estimar los flujos de energía a la superficie. El capítulo 6 presenta un conjunto de ejemplos de aplicaciones operacionales para estimar los flujos de superficie usando datos de teledetección. El primer ejemplo consiste en el estudio de la evolución temporal de mapas de ET en África occidental bajo la influencia del monzón africano. En el segundo ejemplo, se aplica la nueva parametrización de G descrita en el capítulo 4 para calcular y analizar la evolución a largo plazo (2000-2009) de los componentes del balance de energía a la superficie, G, H y ET, en diferentes puntos de la cuenca del río Segura (Sureste español) utilizando datos del sensor MODIS-Terra (temperatura superficial y NDVI). La distribución temporal y espacial de ET revela diferentes controles sobre ET. En el último ejemplo, datos de temperatura superficial del mar del sensor MODIS-Aqua se utilizaron para validar un modelo matemático para calcular los flujos superficiales de una laguna costera del

  7. Enhanced Degradation of Diesel in the Rhizosphere of after Inoculation with Diesel-Degrading and Plant Growth-Promoting Bacterial Strains.

    PubMed

    Balseiro-Romero, María; Gkorezis, Panagiotis; Kidd, Petra S; Vangronsveld, Jaco; Monterroso, Carmen

    2016-05-01

    The association of plants and rhizospheric bacteria provides a successful strategy to clean up contaminated soils. The purpose of this work was to enhance diesel degradation in rhizosphere by inoculation with selected bacterial strains: a diesel degrader (D), plant growth-promoting (PGP) strains, or a combination (D+PGP). Plants were set up in pots with the A or B horizon of an umbric Cambisol (A and B) spiked with diesel (1.25%, w/w). After 1 mo, the dissipation of diesel range organics (DRO) with respect to = 0 (i.e., 1 wk after preparing the pots with the seedlings) concentration was significantly higher in inoculated than in noninoculated (NI) pots: The highest DRO losses were found in A D+PGP pots (close to 15-20% higher than NI) and in B D pots (close to 10% higher). The water-extractable DRO fraction was significantly higher at = 30 d (15-25%) compared with = 0 (<5%), probably due to the effects of plant root exudates and biosurfactants produced by the degrader strain. The results of this experiment reflect the importance of the partnerships between plants and bacterial inoculants and demonstrate the relevance of the effect of bacterial biosurfactants and plant root exudates on contaminant bioavailability, a key factor for enhancing diesel rhizodegradation. The association of lupine with D and PGP strains resulted in a promising combination for application in the rhizoremediation of soils with moderate diesel contamination. PMID:27136159

  8. Community Level Physiological Profiles (CLPP), Characterization and Microbial Activity of Soil Amended with Dairy Sewage Sludge

    PubMed Central

    Frąc, Magdalena; Oszust, Karolina; Lipiec, Jerzy

    2012-01-01

    The aim of the present work was to assess the influence of organic amendment applications compared to mineral fertilization on soil microbial activity and functional diversity. The field experiment was set up on a soil classified as an Eutric Cambisol developed from loess (South-East Poland). Two doses of both dairy sewage sludge (20 Mg·ha−1 and 26 Mg·ha−1) and of mineral fertilizers containing the same amount of nutrients were applied. The same soil without any amendment was used as a control. The soil under undisturbed native vegetation was also included in the study as a representative background sample. The functional diversity (catabolic potential) was assessed using such indices as Average Well Color Development (AWCD), Richness (R) and Shannon–Weaver index (H). These indices were calculated, following the community level physiological profiling (CLPP) using Biolog Eco Plates. Soil dehydrogenase and respiratory activity were also evaluated. The indices were sensitive enough to reveal changes in community level physiological profiles due to treatment effects. It was shown that dairy sewage amended soil was characterized by greater AWCD, R, H and dehydrogenase and respiratory activity as compared to control or mineral fertilized soil. Analysis of variance (ANOVA) and principal component analysis (PCA) were used to depict the differences of the soil bacterial functional diversity between the treatments. PMID:22737006

  9. Planting increases the abundance and structure complexity of soil core functional genes relevant to carbon and nitrogen cycling

    NASA Astrophysics Data System (ADS)

    Wang, Feng; Liang, Yuting; Jiang, Yuji; Yang, Yunfeng; Xue, Kai; Xiong, Jinbo; Zhou, Jizhong; Sun, Bo

    2015-09-01

    Plants have an important impact on soil microbial communities and their functions. However, how plants determine the microbial composition and network interactions is still poorly understood. During a four-year field experiment, we investigated the functional gene composition of three types of soils (Phaeozem, Cambisols and Acrisol) under maize planting and bare fallow regimes located in cold temperate, warm temperate and subtropical regions, respectively. The core genes were identified using high-throughput functional gene microarray (GeoChip 3.0), and functional molecular ecological networks (fMENs) were subsequently developed with the random matrix theory (RMT)-based conceptual framework. Our results demonstrated that planting significantly (P < 0.05) increased the gene alpha-diversity in terms of richness and Shannon - Simpson’s indexes for all three types of soils and 83.5% of microbial alpha-diversity can be explained by the plant factor. Moreover, planting had significant impacts on the microbial community structure and the network interactions of the microbial communities. The calculated network complexity was higher under maize planting than under bare fallow regimes. The increase of the functional genes led to an increase in both soil respiration and nitrification potential with maize planting, indicating that changes in the soil microbial communities and network interactions influenced ecological functioning.

  10. Tracing the sources and spatial distribution of organic carbon in subsoils using a multi-biomarker approach

    PubMed Central

    Angst, Gerrit; John, Stephan; Mueller, Carsten W.; Kögel-Knabner, Ingrid; Rethemeyer, Janet

    2016-01-01

    Soil organic carbon (SOC) from aboveground and belowground sources has rarely been differentiated although it may drive SOC turnover and stabilization due to a presumed differing source dependent degradability. It is thus crucial to better identify the location of SOC from different sources for the parameterization of SOC models, especially in the less investigated subsoils. The aim of this study was to spatially assess contributions of organic carbon from aboveground and belowground parts of beech trees to subsoil organic carbon in a Dystric Cambisol. Different sources of SOC were distinguished by solvent-extractable and hydrolysable lipid biomarkers aided by 14C analyses of soil compartments <63 μm. We found no effect of the distance to the trees on the investigated parameters. Instead, a vertical zonation of the subsoil was detected. A high contribution of fresh leaf- and root-derived organic carbon to the upper subsoil (leaf- and root-affected zone) indicate that supposedly fast-cycling, leaf-derived SOC may still be of considerable importance below the A-horizon. In the deeper subsoil (root-affected zone), roots were an important source of fresh SOC. Simultaneously, strongly increasing apparent 14C ages (3860 yrs BP) indicate considerable contribution of SOC that may be inherited from the Pleistocene parent material. PMID:27380728

  11. Buried palaeosols of the Nevado de Toluca: an alternative record of Late Quaternary environmental change in central Mexico

    NASA Astrophysics Data System (ADS)

    Sedov, Sergey; Solleiro-Rebolledo, Elizabeth; Gama-Castro, Jorge E.; Vallejo-Gómez, Ernestina; González-Velázquez, Arelia

    2001-05-01

    Buried palaeosols of central Mexico, not previously analysed from a palaeopedological standpoint, have helped to develop a reliable regional model of Late Quaternary climatic change. This paper focuses upon morphological and micromorphological properties, particle-size distribution, and extractable Fe, Al and Si of seven palaeosols (named PT1-PT7) in the vicinity of the Nevado de Toluca volcano. The characteristics of Andic Cambisol PT1, similar to those of modern soils in semi-arid environments, indicate a drier climate in the first half of the Holocene. Humic Andosols PT2-PT4 are analogous to modern volcanic soils of humid forest environments. They show evidence that a moist palaeoclimate prevailed during marine oxygen isotope stages (OIS) 2 and 3. Luvisols PT5 and PT6, which are assumed to have formed at the end of marine OIS 5 to marine OIS 4, also indicate humid conditions. We attribute the differences between Andosols PT2-PT4 and Luvisols PT5-PT7 to variations in the duration in the pedogenesis rather than to changes in palaeoclimate. Micromorphological features of Andosol to Luvisol transition confirm that these soils form an evolutionary sequence. Being for the most part consistent with lacustrine records, the palaeosol properties do not reflect the episodes of drier climate during the Last Glacial Maximum, however, as shown by diatom and palynological data from lake sediments. Mesoclimate variations and/or incompleteness of soil memory, reflecting mostly periods of humid pedogenesis, probably provide the reason for this disagreement.

  12. The climosequence approach: Experiences from three continents, lessons learned and future challenges

    NASA Astrophysics Data System (ADS)

    Zehetner, F.; Djukic, I.; Miller, W. P.; Ottner, F.; Tsai, C.-C.; Mentler, A.; Chen, Z.-S.; Gerzabek, M. H.

    2009-04-01

    Soil climosequences are, by definition, sequences of soils whose variations are caused by differences in climatic conditions. In the real world, vegetation almost always co-varies along climatic gradients. Therefore, most soil climosequences are implicitly also vegetation-sequences. Here, we report results from three soil climosequence studies along altitudinal / climatic gradients in South America, Asia and Europe. On 3000-yr-old volcanic parent material in Ecuador, we observed precipitation of amorphous materials and accumulation of organic matter at high elevations, whereas halloysite dominated the clay mineralogy at low elevations. The different pedogenic pathways strongly affect the soils' present fertility and erodibility. On 200,000-yr-old volcanic deposits in Taiwan, the high-elevation soils also contained high amounts of amorphous materials and organic matter, whereas the low-elevation soils were dominated by gibbsite, kaolinite and hematite. On both volcanic climosequences, "andic" soil properties increased with elevation, resulting in taxonomic sequences from low-elevation Cambisols to high-elevation Andosols. In the Austrian Limestone Alps, we studied a climosequence of organic matter-dominated soils (Histosols) and found altitudinal trends in organic carbon stocks, organic matter quality as well as microbial community composition. Despite the wealth of information we can obtain from soil climosequence studies, this approach faces several challenges that need to be tackled by the scientific community in the future.

  13. Edaphic factors affecting the vertical distribution of radionuclides in the different soil types of Belgrade, Serbia.

    PubMed

    Dragović, Snežana; Gajić, Boško; Dragović, Ranko; Janković-Mandić, Ljiljana; Slavković-Beškoski, Latinka; Mihailović, Nevena; Momčilović, Milan; Ćujić, Mirjana

    2012-01-01

    The specific activities of natural radionuclides ((40)K, (226)Ra and (232)Th) and Chernobyl-derived (137)Cs were measured in soil profiles representing typical soil types of Belgrade (Serbia): chernozems, fluvisols, humic gleysols, eutric cambisols, vertisols and gleyic fluvisols. The influence of soil properties and content of stable elements on radionuclide distribution down the soil profiles (at 5 cm intervals up to 50 cm depth) was analysed. Correlation analysis identified associations of (40)K, (226)Ra and (137)Cs with fine-grained soil fractions. Significant positive correlations were found between (137)Cs specific activity and both organic matter content and cation exchange capacity. Saturated hydraulic conductivity and specific electrical conductivity were also positively correlated with the specific activity of (137)Cs. The strong positive correlations between (226)Ra and (232)Th specific activities and Fe and Mn indicate an association with oxides of these elements in soil. The correlations observed between (40)K and Cr, Ni, Pb and Zn and also between (137)Cs and Cd, Cr, Pb and Zn could be attributed to their common affinity for clay minerals. These results provide insight into the main factors that affect radionuclide migration in the soil, which contributes to knowledge about radionuclide behaviour in the environment and factors governing their mobility within terrestrial ecosystems. PMID:22072061

  14. Leptospirosis Outbreaks in Nicaragua: Identifying Critical Areas and Exploring Drivers for Evidence-Based Planning

    PubMed Central

    Schneider, Maria Cristina; Nájera, Patricia; Aldighieri, Sylvain; Bacallao, Jorge; Soto, Aida; Marquiño, Wilmer; Altamirano, Lesbia; Saenz, Carlos; Marin, Jesus; Jimenez, Eduardo; Moynihan, Matthew; Espinal, Marcos

    2012-01-01

    Leptospirosis is an epidemic-prone zoonotic disease that occurs worldwide. In Central America, leptospirosis outbreaks have been reported in almost all countries; Nicaragua in particular has faced several outbreaks. The objective of this study was to stratify the risk and identify “critical areas” for leptospirosis outbreaks in Nicaragua, and to perform an exploratory analysis of potential “drivers”. This ecological study includes the entire country (153 municipalities). Cases from 2004 to 2010 were obtained from the country’s health information system, demographic and socioeconomic variables from its Census, and environmental data from external sources. Criteria for risk stratification of leptospirosis were defined. Nicaragua reported 1,980 cases of leptospirosis during this period, with the highest percentage of cases (26.36%) in León, followed by Chinandega (15.35%). Among the 153 municipalities, 48 were considered critical areas, 85 were endemic and 20 silent. Using spatial and statistical analysis, the variable presenting the most evident pattern of association with critical areas defined by top quintile of incidence rate is the percentage of municipal surface occupied by the soil combination of cambisol (over pyroclastic and lava bedrock) and andosol (over a volcanic ashes foundation). Precipitation and percentage of rural population are also associated with critical areas. This methodology and findings could be used for Nicaragua’s Leptospirosis Intersectoral Plan, and to identify possible risk areas in other countries with similar drivers. PMID:23202822

  15. Long-term organic-inorganic fertilization ensures great soil productivity and bacterial diversity after natural-to-agricultural ecosystem conversion.

    PubMed

    Xun, Weibing; Xu, Zhihui; Li, Wei; Ren, Yi; Huang, Ting; Ran, Wei; Wang, Boren; Shen, Qirong; Zhang, Ruifu

    2016-09-01

    Natural ecosystems comprise the planet's wild plant and animal resources, but large tracts of land have been converted to agroecosystems to support the demand for agricultural products. This conversion limits the number of plant species and decreases the soil biological diversity. Here we used high-throughput 16S rRNA gene sequencing to evaluate the responses of soil bacterial communities in long-term converted and fertilized red soils (a type of Ferralic Cambisol). We observed that soil bacterial diversity was strongly affected by different types of fertilization management. Oligotrophic bacterial taxa demonstrated large relative abundances in chemically fertilized soil, whereas copiotrophic bacterial taxa were found in large relative abundances in organically fertilized and fallow management soils. Only organic-inorganic fertilization exhibited the same local taxonomic and phylogenetic diversity as that of a natural ecosystem. However, the independent use of organic or inorganic fertilizer reduced local taxonomic and phylogenetic diversity and caused biotic homogenization. This study demonstrated that the homogenization of bacterial communities caused by natural-to-agricultural ecosystem conversion can be mitigated by employing rational organic-inorganic fertilization management. PMID:27572510

  16. High-temporal resolution radiocarbon analyses of dissolved organic matter in soils from a mountainous and temperate ecosystem

    NASA Astrophysics Data System (ADS)

    van der Voort, Tessa Sophia; Graf Pannatier, Elisabeth; McIntyre, Cameron; Hagedorn, Frank; Eglinton, Timothy

    2016-04-01

    A better understanding of the stability and turnover of soil dissolved organic matter (DOM) is key in order to predict the behavior and response of this dynamic carbon pool to climate and land use change. Radiocarbon is increasingly used to determine carbon turnover in carbon cycle studies. However, due to the nature of radiocarbon measurement as well as complexity of in-situ DOM collection, little comprehensive radiocarbon and turnover data is currently available. This project combines a high-resolution temporal DOM sequence for a mountainous (podzol) and temperate (cambisol) forest ecosystem with additional bulk- and fraction-specific soil organic matter analyses. DOM was collected bi-weekly on two sites of the Long-Term Forest Ecosystem Research (LWF) program of the Swiss Federal Institute for Forest, Snow and Landscape research (WSL) at four depths, and measured for radiocarbon content. These initial results indicate bi-weekly variation in radiocarbon signatures over the summer season and a strong soil-type dependent pattern in DO14C trend. Overall, these initial radiocarbon results indicate that DOM dynamics are seasonally variable, and thus could potentially be sensitive to future climate change. Furthermore, the DO14C trend helps to better understand the trends as can be seen in the bulk 14C signature of the soil organic matter. Detailed radiocarbon investigations of soil DOM may yield key insights into the complex carbon transport dynamics in different soil systems and their potential behavior under climate change scenarios.

  17. The impact of vegetation on humus formation and morphology of brown forest soils in coastal areas of the southeastern part of Russian far east

    NASA Astrophysics Data System (ADS)

    Pshenichnikov, B. F.; Pshenichnikova, N. F.

    2015-04-01

    Specific features of brown forest soils (burozems, Cambisols) in coastal areas of the southeastern part of Russian Far East are discussed. It is shown that the color of the illuvial horizons in these soils depends on the character of vegetation; it is reddish brown under oak forests and dark gray under herb-shrub and post-pyrogenic communities. These soils combine the features shaped by the humus-accumulative and humus-illuvial processes. In the soils under oak forests, the humate-fulvate type of humus predominates; in the soils under herb-shrub and post-pyrogenic communities, the fulvate-humate humus is formed. The dynamics of humus and its separate fractions in the soil profiles control the morphochromatic differentiation of brown forest soils under different vegetation communities. In the soils under oak forests, the maximum precipitation of the aggressive fraction of fulvic acids (fraction FA-1a) in the illuvial-humus horizons coincides with the maximum concentration of oxalate-extractable iron oxides; these substances ensure the reddish brown color of the illuvial horizons in these soils. In the brown forest soils under herb-shrub and post-pyrogenic communities, the illuvial horizon is the zone of accumulation of not only the aggressive fraction of fulvic acids but also the second (Ca-bound) fractions of fulvic and humic acids ensuring the dark gray color of this horizon.

  18. Vertical nutrient and trace element migration in cambisoils after application of residues from anaerobic digestion of pig manure

    NASA Astrophysics Data System (ADS)

    Sager, Manfred; Unterfrauner, Hans

    2013-04-01

    Cambisols sampled in alpine pastures were packed into soil columns in order to monitor downward migration of nutrient and trace elements, applied within the residue from anaerobic digestion of a pig manure. 2 rain events per week were simulated. The manure added substantial amounts of K, ammonium, Na, Ca, P, S, Cl, B, Zn and Cu to the soil, whereas Mg, Mn, Ni, Cr, Pb, Cd and V were at the same level. In the eluates, total elemental composition as well as nitrate and ammonium were monitored. Addition of soluble Fe (at 1000 mg/l as FeCl3) decreased the release of soluble sulphate, but had no significant effect on the release of Fe and P. During subsequent rain events, exchangeable K remained enriched in the topsoil, wheras total sulfur moved to deeper layers. After 8 weeks, the columns were dismantled and analyzed for quasi-total and mobile fractions. Both in topsoils and subsoils, manure addition finally increased soil pH in case of low P soils, but decreased soil pH in case of high pH soils. Effects of manure applications on groundwater formation processes will be discussed.

  19. Animal-powered tillage erosion assessment in the southern Andes region of Ecuador

    NASA Astrophysics Data System (ADS)

    Dercon, G.; Govers, G.; Poesen, J.; Sánchez, H.; Rombaut, K.; Vandenbroeck, E.; Loaiza, G.; Deckers, J.

    2007-06-01

    While water erosion has been the focus of past research in the Andes, former studies show that soil erosion could also be related to the methods used in cultivating the fields. The main objective of the present study was to assess (i) tillage erosion caused by the traditional animal-powered "yunta" or ard plough in the Andes and the factors controlling the process and (ii) the implications for soil conservation. Erosion rates were experimentally measured on 27 sites, having slopes from ca. 0% to 60% and soils ranging from Andosols to Cambisols, in the Andes region of Ecuador (Gima, Azuay). Different tillage methods were assessed: (i) tillage parallel to the contour lines ('Paralelo') and (ii) tillage at an angle with the contour lines. Statistical analysis points out that erosion caused by animal-powered tillage is gravity-driven. A strong correlation exists between slope and downslope displacement: furthermore, tillage depth and initial soil condition are important. For the 'Paralelo' tillage method the tillage transportation coefficient ( k) is below 100 kg m - 1 Tillage Pass - 1 , for the combined 'Arado'-'Cruzado' tillage method k may exceed 300 kg m - 1 . Tillage erosion is responsible for the reduction of the slope between the contour strips over a relatively short time period of 20 years, resulting in the formation of terraces and therefore the reduction of the water erosion risk. However, at the same time it may negatively affect soil quality.

  20. Validation of TOF-SIMS and FE-SEM/EDS Techniques Combined with Sorption and Desorption Experiments to Check Competitive and Individual Pb2+ and Cd2+ Association with Components of B Soil Horizons

    PubMed Central

    Andrade, María Luisa; Vega, Flora A.

    2015-01-01

    Sorption and desorption experiments were performed by the batch method on the B horizons of five natural soils: Umbric Cambisol, Endoleptic Luvisol, Mollic Umbrisol, Dystric Umbrisol, and Dystric Fluvisol. Individual and competitive sorption and desorption capacity and hysteresis were determined. The results showed that Pb2+ was sorbed and retained in a greater quantity than Cd2+ and that the hysteresis of the first was greater than that of the second. The most influential characteristics of the sorption and retention of Pb2+ were pH, ECEC, Fe and Mn oxides and clay contents. For Cd2+ they were mainly pH and, to a lesser extent, Mn oxides and clay content. The combined use of TOF-SIMS, FE-SEM/EDS and sorption and desorption analyses was suitable for achieving a better understanding of the interaction between soil components and the two heavy metals. They show the preferential association of Pb2+ with vermiculite, chlorite, Fe and Mn oxides, and of Cd2+ with the same components, although to a much lesser extent and intensity. This was due to the latter’s higher mobility as it competed unfavourably with the Pb2+ sorption sites. TOF-SIMS and FE-SEM/EDS techniques confirmed the results of the sorption experiments, and also provided valuable information on whether the soil components (individually or in association) retain Cd2+ and / or Pb2+; this could help to propose effective measures for the remediation of contaminated soils. PMID:25893518

  1. Tracing the sources and spatial distribution of organic carbon in subsoils using a multi-biomarker approach.

    PubMed

    Angst, Gerrit; John, Stephan; Mueller, Carsten W; Kögel-Knabner, Ingrid; Rethemeyer, Janet

    2016-01-01

    Soil organic carbon (SOC) from aboveground and belowground sources has rarely been differentiated although it may drive SOC turnover and stabilization due to a presumed differing source dependent degradability. It is thus crucial to better identify the location of SOC from different sources for the parameterization of SOC models, especially in the less investigated subsoils. The aim of this study was to spatially assess contributions of organic carbon from aboveground and belowground parts of beech trees to subsoil organic carbon in a Dystric Cambisol. Different sources of SOC were distinguished by solvent-extractable and hydrolysable lipid biomarkers aided by (14)C analyses of soil compartments <63 μm. We found no effect of the distance to the trees on the investigated parameters. Instead, a vertical zonation of the subsoil was detected. A high contribution of fresh leaf- and root-derived organic carbon to the upper subsoil (leaf- and root-affected zone) indicate that supposedly fast-cycling, leaf-derived SOC may still be of considerable importance below the A-horizon. In the deeper subsoil (root-affected zone), roots were an important source of fresh SOC. Simultaneously, strongly increasing apparent (14)C ages (3860 yrs BP) indicate considerable contribution of SOC that may be inherited from the Pleistocene parent material. PMID:27380728

  2. Effect of the Entrapped air on Water Flow in Heterogeneous Soil: Experimental Set- up

    NASA Astrophysics Data System (ADS)

    Snehota, M.; Sobotkova, M.; Cislerova, M.

    2008-12-01

    Temporal variations of steady state water flow rates were observed in laboratory infiltration experiments done on a sample of compacted sand and on an undisturbed soil sample (Eutric Cambisol). These variations are found to be in relation with entrapped air content. Infiltration-outflow experiments consisted of a series of ponded infiltration runs with seepage face boundary condition at the lower end of columns. The amount of the entrapped was derived from continuous weighing of the sample. The initial water contents were different for each run, which led to different amount of the air trapped in the soil during the first stages of infiltrations. The results of the experiments done on undisturbed soil showed that the flux rates and water contents varied during quasi-steady state. This finding contradicts the standard theory. The fluctuations of the water content during the steady state flow can be ascribed to the variations in volume of the entrapped air. Similarly, shape of the bromide breakthrough curve, which were performed simultaneously during the quasi-steady state varied for undisturbed soil. The same behaviour was not observed in the sample of homogeneous sand. Computer tomography was used to characterize the structure of the undisturbed soil sample with focus on potential preferential flow pathways, which are likely to host the entrapped air. To formulate more general conclusions, an extended series of infiltration outflow and bromide breakthrough experiments is in progress. This research has been supported by research project GACR 103/08/1552 and MSMT CEZ MSM 6840770002.

  3. Tracing the sources and spatial distribution of organic carbon in subsoils using a multi-biomarker approach

    NASA Astrophysics Data System (ADS)

    Angst, Gerrit; John, Stephan; Mueller, Carsten W.; Kögel-Knabner, Ingrid; Rethemeyer, Janet

    2016-07-01

    Soil organic carbon (SOC) from aboveground and belowground sources has rarely been differentiated although it may drive SOC turnover and stabilization due to a presumed differing source dependent degradability. It is thus crucial to better identify the location of SOC from different sources for the parameterization of SOC models, especially in the less investigated subsoils. The aim of this study was to spatially assess contributions of organic carbon from aboveground and belowground parts of beech trees to subsoil organic carbon in a Dystric Cambisol. Different sources of SOC were distinguished by solvent-extractable and hydrolysable lipid biomarkers aided by 14C analyses of soil compartments <63 μm. We found no effect of the distance to the trees on the investigated parameters. Instead, a vertical zonation of the subsoil was detected. A high contribution of fresh leaf- and root-derived organic carbon to the upper subsoil (leaf- and root-affected zone) indicate that supposedly fast-cycling, leaf-derived SOC may still be of considerable importance below the A-horizon. In the deeper subsoil (root-affected zone), roots were an important source of fresh SOC. Simultaneously, strongly increasing apparent 14C ages (3860 yrs BP) indicate considerable contribution of SOC that may be inherited from the Pleistocene parent material.

  4. Release of aged 14C-atrazine residues from soil facilitated by dry-wet cycles

    NASA Astrophysics Data System (ADS)

    Jablonowski, N. D.; Yu, K.; Koeppchen, S.; Burauel, P.

    2012-04-01

    Intermittent dry-wet cycles may have an important effect on soil structure and aged pesticide residues release (1). A laboratory study was conducted to assess the maximum potential of water extractable aged atrazine residues influenced by soil drying and wetting. The used soil was obtained from an outdoor lysimeter (gleyic cambisol; Corg: 1.45%), containing environmentally aged (22 years) 14C-atrazine residues. For the experiment, soil from 0-10 cm depth was used since most residual 14C activity was previously found in this layer (2,3). Triplicate soil samples with a residual water content of approx. 8% were either dried (45° C) prior water addition or directly mixed with distilled water (soil+water: 1+2, w:w). The samples were shaken (150 rmp, 60 min, at 21° C), centrifuged (approx. 2000 g), and the supernatants were filtered. Water-extracted residual 14C activity was detected via liquid scintillation counter. The total water-extracted 14C activity (the amount of residual 14C activity in a sample equals 100%) was significantly higher (p

  5. Analysis of the sorption properties of different soils using water vapour adsorption and potentiometric titration methods

    NASA Astrophysics Data System (ADS)

    Skic, Kamil; Boguta, Patrycja; Sokołowska, Zofia

    2016-07-01

    Parameters of specific surface area as well as surface charge were used to determine and compare sorption properties of soils with different physicochemical characteristics. The gravimetric method was used to obtain water vapour isotherms and then specific surface areas, whereas surface charge was estimated from potentiometric titration curves. The specific surface area varied from 12.55 to 132.69 m2 g-1 for Haplic Cambisol and Mollic Gleysol soil, respectively, and generally decreased with pH (R=0.835; α = 0.05) and when bulk density (R=-0.736; α = 0.05) as well as ash content (R=-0.751; α = 0.05) increased. In the case of surface charge, the values ranged from 63.00 to 844.67 μmol g-1 Haplic Fluvisol and Mollic Gleysol, respecively. Organic matter gave significant contributions to the specific surface area and cation exchange capacity due to the large surface area and numerous surface functional groups, containing adsorption sites for water vapour molecules and for ions. The values of cation exchange capacity and specific surface area correlated linearly at the level of R=0.985; α = 0.05.

  6. Soil type recognition as improved by genetic algorithm-based variable selection using near infrared spectroscopy and partial least squares discriminant analysis.

    PubMed

    Xie, Hongtu; Zhao, Jinsong; Wang, Qiubing; Sui, Yueyu; Wang, Jingkuan; Yang, Xueming; Zhang, Xudong; Liang, Chao

    2015-01-01

    Soil types have traditionally been determined by soil physical and chemical properties, diagnostic horizons and pedogenic processes based on a given classification system. This is a laborious and time consuming process. Near infrared (NIR) spectroscopy can comprehensively characterize soil properties, and may provide a viable alternative method for soil type recognition. Here, we presented a partial least squares discriminant analysis (PLSDA) method based on the NIR spectra for the accurate recognition of the types of 230 soil samples collected from farmland topsoils (0-10 cm), representing 5 different soil classes (Albic Luvisols, Haplic Luvisols, Chernozems, Eutric Cambisols and Phaeozems) in northeast China. We found that the PLSDA had an internal validation accuracy of 89% and external validation accuracy of 83% on average, while variable selection with the genetic algorithm (GA and GA-PLSDA) improved this to 92% and 93%. Our results indicate that the GA variable selection technique can significantly improve the accuracy rate of soil type recognition using NIR spectroscopy, suggesting that the proposed methodology is a promising alternative for recognizing soil types using NIR spectroscopy. PMID:26086823

  7. Experimental Investigation of Preferential Flow in a Near-saturated Intact Soil Sample

    NASA Astrophysics Data System (ADS)

    Snehota, Michal; Jelinkova, Vladimira; Sacha, Jan; Frycova, Martina; Cislerova, Milena; Vontobel, Peter; Hovind, Jan

    Hydraulic conductivity in an intact sample of coarse sandy loam from the Cambisol series containing a naturally developed, vertically connected macropore was investigated during a recurrent ponding infiltration (RPI) experiment performed over a period of 30 hours, in combination with neutron tomography imaging. The RPI experiment consisted of two consecutive ponded infiltration runs, each followed by free gravitational draining of the sample. Three-dimensional neutron tomography (NT) imaging of the dry sample was acquired before the infiltration began. The dynamics of the advancement of the wetting front was investigated using a sequence of neutron radiography (NR) images. Analysis of these images showed that the water front moved preferentially through the macropore at an approximate speed of 2 mm/s, significantly faster than the 0.3 mm/s wetting advancement in the surrounding soil matrix. After outflow started temporal changes in the local water content distribution were evaluated quantitatively by subtracting the NT image of the dry sample from the particular tomography images generated during infiltration runs. The neutron tomography data quantitatively showed the transfer of air from the soil matrix to the macropore. Accumulation of air bubbles in the macropore then affected the hydraulic conductivity of the sample reducing it to 50% of the initial value.

  8. Modeling the impact of conservation agriculture on crop production and soil properties in Mediterranean climate

    NASA Astrophysics Data System (ADS)

    Moussadek, Rachid; Mrabet, Rachid; Dahan, Rachid; Laghrour, Malika; Lembiad, Ibtissam; ElMourid, Mohamed

    2015-04-01

    In Morocco, rainfed agriculture is practiced in the majority of agricultural land. However, the intensive land use coupled to the irregular rainfall constitutes a serious threat that affect country's food security. Conservation agriculture (CA) represents a promising alternative to produce more and sustainably. In fact, the direct seeding showed high yield in arid regions of Morocco but its extending to other more humid agro-ecological zones (rainfall > 350mm) remains scarce. In order to promote CA in Morocco, differents trials have been installed in central plateau of Morocco, to compare CA to conventional tillage (CT). The yields of the main practiced crops (wheat, lentil and checkpea) under CA and CT were analyzed and compared in the 3 soils types (Vertisol, Cambisol and Calcisol). Also, we studied the effect of CA on soil organic matter (SOM) and soil losses (SL) in the 3 different sites. The APSIM model was used to model the long term impact of CA compared to CT. The results obtained in this research have shown favorable effects of CA on crop production, SOM and soil erosion. Key words: Conservation agriculture, yield, soil properties, modeling, APSIM, Morocco.

  9. Conventional tillage vs. organic farming in relation to soil organic carbon stock in olive groves in Mediterranean rangelands (Southern Spain)

    NASA Astrophysics Data System (ADS)

    Parras-Alcántara, L.; Lozano-García, B.

    2014-01-01

    Soil organic carbon (SOC) concentration is a soil variable subject to changes. In agricultural soils, the management system is a key factor that influence to these changes. For determine the management system effects on SOC stocks (SOC-S) in olive groves, 114 soil profiles were studied in the Los Pedroches Valley (Mediterranean rangelands - southern Spain) for long-term (20 yr). The management practices were conventional tillage (CT) and organic farming (OF) in four soil types: Cambisols (CM), Regosols (RG), Luvisols (LV) and Leptosols (LP). Soil properties were statistically analyzed by management techniques, soil types and horizons. The principal components analyses identified four factors that explained 65% of the variance. Also, significant differences (p < 0.05) were found between soil types and management techniques. Equally was observed that the management system affected to SOC-S. In addition, the total SOC-S for 20 yr increased in OF with respect to CT by 72% and 66% in CM and LV respectively. The SOC showed significant differences for horizons (p < 0.05) in relation to the management types. The stratification ratio index of SOC was >2 in all studied soils. These results indicate high soils quality, and that management practices affect to SOC store in the Los Pedroches Valley.

  10. Long-term fertilization effects on soil organic carbon fractions in a red soil of southern China

    NASA Astrophysics Data System (ADS)

    Tong, X.; Xu, M.; Wang, X.; Zhang, W.; Cong, R.

    2010-12-01

    This paper presents a study of long-term (17 years) fertilization effects on soil organic carbon (SOC) fractions in a typical red soil (Ferralic Cambisol) under intensive cropping with maize-wheat with various fertilizations in Hunan, China. The fertilization treatments include non-fertilization (Control), mineral nitrogen (N), mineral nitrogen-phosphorus (NP), nitrogen-phosphorus-potassium combination (NPK), and mineral NPK combined with organic amendments (e.g., pig manure and straw). Two sets of soil samples were used: (1) collected in 1990, and (2) collected in 2007. Soil samples were separated to measure free particulate organic C (fPOC), intra-microaggregate particulate organic C (iPOC), and mineral associated organic C (MOC) with physical fractionation. The percentage of SOC fractions in all treatments follows an order: MOC (45-89%) >fPOC (7-35%) >iPOC (11-20%), suggesting that MOC is the primary organic carbon pool in the red soil. Compared with the control, there is no increase in iPOC and MOC under imbalanced mineral fertilizer applications (i.e., N, NP). However, all SOC fractions show a significant increase under balanced mineral fertilizer application (NPK), and mineral NPK applied with organic amendments. Particularly, manure application results in an increase of 290.6-408.3 kg ha-1 yr-1 for fPOC, 162.0-179.2 kg ha-1 yr-1 for iPOC and 322.9-514.5 kg ha-1 yr-1 for MOC.

  11. Validation of TOF-SIMS and FE-SEM/EDS Techniques Combined with Sorption and Desorption Experiments to Check Competitive and Individual Pb2+ and Cd2+ Association with Components of B Soil Horizons.

    PubMed

    Cerqueira, Beatriz; Arenas-Lago, Daniel; Andrade, María Luisa; Vega, Flora A

    2015-01-01

    Sorption and desorption experiments were performed by the batch method on the B horizons of five natural soils: Umbric Cambisol, Endoleptic Luvisol, Mollic Umbrisol, Dystric Umbrisol, and Dystric Fluvisol. Individual and competitive sorption and desorption capacity and hysteresis were determined. The results showed that Pb2+ was sorbed and retained in a greater quantity than Cd2+ and that the hysteresis of the first was greater than that of the second. The most influential characteristics of the sorption and retention of Pb2+ were pH, ECEC, Fe and Mn oxides and clay contents. For Cd2+ they were mainly pH and, to a lesser extent, Mn oxides and clay content. The combined use of TOF-SIMS, FE-SEM/EDS and sorption and desorption analyses was suitable for achieving a better understanding of the interaction between soil components and the two heavy metals. They show the preferential association of Pb2+ with vermiculite, chlorite, Fe and Mn oxides, and of Cd2+ with the same components, although to a much lesser extent and intensity. This was due to the latter's higher mobility as it competed unfavourably with the Pb2+ sorption sites. TOF-SIMS and FE-SEM/EDS techniques confirmed the results of the sorption experiments, and also provided valuable information on whether the soil components (individually or in association) retain Cd2+ and/or Pb2+; this could help to propose effective measures for the remediation of contaminated soils. PMID:25893518

  12. Ephemeral Fe(II)/Fe(III) layered double hydroxides in hydromorphic soils: A review

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.; Shoba, S. A.

    2015-03-01

    Ephemeral green rust is formed seasonally in some hydromorphic soils. It consists of Fe(II)/Fe(III) layered double hydroxides with different types of interlayer anions and different oxidation degrees of iron ( x). In synthetized stoichiometric green rust, x = 0.25-0.33; in soil fougerite, it may reach 0.50-0.66. The mineral stability is provided by the partial substitution of Mg2+ for Fe2+. The ephemeral properties of the green rust are manifested in the high sensitivity to the varying redox regime in hydromorphic soils. Green rust disappears during oxidation stages, which complicates its diagnostics in soils. For green rust formation, excessively moist mineral soil needs organic matter as a source of energy for the vital activity of iron-reducing bacteria. In a gleyed Cambisol France, where fougerite is formed in the winter, the index of hydrogen partial pressure rH2 is 7.0-8.2, which corresponds to highly reducing conditions; upon the development of oxidation, fougerite is transformed into lepidocrocite. In the mineral siderite horizon of peatbogs in Belarus, where green rust is formed in the summer, rH2 is 11-14, which corresponds to the lower boundary of reducing conditions ( rH2 = 10-18); magnetite is formed in these soils in the winter season upon dehydration of the soil mass.

  13. Planting increases the abundance and structure complexity of soil core functional genes relevant to carbon and nitrogen cycling

    PubMed Central

    Wang, Feng; Liang, Yuting; Jiang, Yuji; Yang, Yunfeng; Xue, Kai; Xiong, Jinbo; Zhou, Jizhong; Sun, Bo

    2015-01-01

    Plants have an important impact on soil microbial communities and their functions. However, how plants determine the microbial composition and network interactions is still poorly understood. During a four-year field experiment, we investigated the functional gene composition of three types of soils (Phaeozem, Cambisols and Acrisol) under maize planting and bare fallow regimes located in cold temperate, warm temperate and subtropical regions, respectively. The core genes were identified using high-throughput functional gene microarray (GeoChip 3.0), and functional molecular ecological networks (fMENs) were subsequently developed with the random matrix theory (RMT)-based conceptual framework. Our results demonstrated that planting significantly (P < 0.05) increased the gene alpha-diversity in terms of richness and Shannon – Simpson’s indexes for all three types of soils and 83.5% of microbial alpha-diversity can be explained by the plant factor. Moreover, planting had significant impacts on the microbial community structure and the network interactions of the microbial communities. The calculated network complexity was higher under maize planting than under bare fallow regimes. The increase of the functional genes led to an increase in both soil respiration and nitrification potential with maize planting, indicating that changes in the soil microbial communities and network interactions influenced ecological functioning. PMID:26396042

  14. Raindrop induced crust formation

    NASA Astrophysics Data System (ADS)

    Szabó, Judit Alexandra; Jakab, Gergely; Józsa, Sándor; Németh, Tibor; Kovács, Ivett; Szalai, Zoltán

    2016-04-01

    Rainfall simulators are wildly used to study soil erosion because all parts of the erosion process can be simulated with them. Small-scale laboratory rainfall simulator was used to examine the detachment phase of the erosion and study the redistribution trend of the organic and mineral components of the soil. Splash erosion often creates crust on the soil surface that decreases porosity and infiltration. Crusts have crucial role in physical soil degradation processes, erosion and crop production fall. Intensive rainfall on a recently tilled Regosol and a Cambisol plots detached the aggregates and the occurred runoff scattered the individual particles on the surface. Oriented thin sections from the various morphological types of surface crusts were made similar as a thin section from any rock but during the preparation the samples were saturated often with dilute two-component adhesive to solidify the soil to preserve the crust. Raman spectroscopy and XRD analysis measurements are in progress in order to identify spatial changes in organic matter and mineralogical composition among the crust layers. Preliminary results suggest the separation of the mineral and organic soil components. The lighter organic matter seems to be enriched in the soil loss while the heavier minerals are deposited and stratified in the deeper micromorphological positions of the surface. The understanding of this selectivity is necessary in soil loss estimation.

  15. Bruno Braunerde und die Bodentypen - Learning about soil diversity and soil functions with cartoon characters

    NASA Astrophysics Data System (ADS)

    Hofmann, Anett

    2015-04-01

    "Bruno Braunerde und die Bodentypen" is a German-language learning material that fosters discovery of soil diversity and soil functions in kids, teens and adults who enjoy interactive learning activities. The learning material consists of (i) a large poster (dimensions 200 x 120 cm) showing an imaginative illustrated landscape that could be situated in Austria, Switzerland or southern Germany and (ii) a set of 15 magnetic cards that show different soil cartoon characters, e.g. Bruno Braunerde (Cambisol), Stauni Pseudogley (Stagnic Luvisol) or Heidi Podsol (Podzol) on the front and a fun profession and address (linked to the respective soil functions) on the back side. The task is to place the soil cartoon characters to their 'home' in the landscape. This learning material was developed as a contribution to the International Year of Soils 2015 and is supported by the German, Austrian and Swiss Soil Sciences Societies and the Swiss Federal Office for the Environment. The soil cartoon characters are an adaptation of the original concept by the James Hutton Institute, Aberdeen, Scotland (www.hutton.ac.uk/learning/dirt-doctor).

  16. In situ visualisation and characterisation of the capacity of highly reactive minerals to preserve soil organic matter (SOM) in colloids at submicron scale.

    PubMed

    Xiao, Jian; Wen, Yongli; Li, Huan; Hao, Jialong; Shen, Qirong; Ran, Wei; Mei, Xinlan; He, Xinhua; Yu, Guanghui

    2015-11-01

    Mineral-organo associations (MOAs) are a mixture of identifiable biopolymers associated with highly reactive minerals and microorganisms. However, the in situ characterization and correlation between soil organic matter (SOM) and highly reactive Al and Fe minerals are still unclear for the lack of technologies, particularly in the long-term agricultural soil colloids at submicron scale. We combined several novel techniques, including nano-scale secondary ion mass spectrometry (NanoSIMS), X-ray absorption near edge structure (XANES) and confocal laser scanning microscopy (CLSM) to characterise the capacity of highly reactive Al and Fe minerals to preserve SOM in Ferralic Cambisol in south China. Our results demonstrated that: (1) highly reactive minerals were strongly related to SOM preservation, while SOM had a more significant line correlation with the highly reactive Al minerals than the highly reactive Fe minerals, according to the regions of interest correlation analyses using NanoSIMS; (2) allophane and ferrihydrite were the potential mineral species to determine the SOM preservation capability, which was evaluated by the X-ray photoelectron spectroscopy (XPS) and Fe K-edge XANES spectroscopy techniques; and (3) soil organic biopolymers with dominant compounds, such as proteins, polysaccharides and lipids, were distributed at the rough and clustered surface of MOAs with high chemical and spatial heterogeneity according to the CLSM observation. Our results also promoted the understanding of the roles played by the highly reactive Al and Fe minerals in the spatial distribution of soil organic biopolymers and SOM sequestration. PMID:26091865

  17. Leachability of volatile fuel compounds from contaminated soils and the effect of plant exudates: A comparison of column and batch leaching tests.

    PubMed

    Balseiro-Romero, María; Kidd, Petra S; Monterroso, Carmen

    2016-03-01

    Volatile fuel compounds such as fuel oxygenates (FO) (MTBE and ETBE) and BTEX (benzene, toluene, ethylbenzene and xylene) are some of the most soluble components of fuel. Characterizing the leaching potential of these compounds is essential for predicting their mobility through the soil profile and assessing the risk of groundwater contamination. Plant root exudates can play an important role in the modification of contaminant mobility in soil-plant systems, and such effects should also be considered in leaching studies. Artificially spiked samples of A and B horizons from an alumi-umbric Cambisol were leached in packed-columns and batch experiments using Milli-Q water and plant root exudates as leaching agents. The leaching potential and rate were strongly influenced by soil-contaminant interactions and by the presence of root exudates. Organic matter in A horizon preferably sorbed the most non-polar contaminants, lowering their leaching potential, and this effect was enhanced by the presence of root exudates. On the other hand, the inorganic components of the B horizon, showed a greater affinity for polar molecules, and the presence of root exudates enhanced the desorption of the contaminants. Column experiments resulted in a more realistic protocol than batch tests for predicting the leaching potential of volatile organic compounds in dissimilar soils. PMID:26619047

  18. Combining neutron and X-ray imaging to study air and water behaviour in the soil macropores

    NASA Astrophysics Data System (ADS)

    Snehota, Michal; Sobotkova, Martina; Jelinkova, Vladimira; Kaestner, Anders

    2016-04-01

    Infiltration of water and gas trapping in soil macropores were investigated on intact sample of coarse sandy loam soil (Cambisol series) taken from the B horizon by combined X-ray and neutron tomography imaging. The soil under study is known for the occurrence of the preferential flow, in which a majority of the water flux is conducted through small, highly conductive, fraction of the soil volume. Experiment performed in the NEUTRA beamline of Paul Scherrer Institut consisted of two infiltration episodes during which a layer of heavy and light water mixture was maintained on the sample surface created a ponding boundary condition. The initial state of the sample was recorded by one X-ray and two neutron scans prior to the first infiltration. Another 20 neutron tomograms were acquired during the following 25 hours of the experiment. Fine co-registration of the reconstructed X-ray and neutron tomograms was performed. Then, bi-variate histograms helped to identify the thresholds that were subsequently used for segmentation of the macropores from the X-ray tomograms. The segmented regions served as a binary mask for calculating the water volume using the neutron tomograms. Volume of water and subsequently the average water content in the macropore system were calculated. Results then quantitatively show the extent of the water content reduction in the macropores during the second infiltration that was caused by enhanced air trapping in the wet soil.

  19. Conventional tillage versus organic farming in relation to soil organic carbon stock in olive groves in Mediterranean rangelands (southern Spain)

    NASA Astrophysics Data System (ADS)

    Parras-Alcántara, L.; Lozano-García, B.

    2014-05-01

    Soil organic carbon (SOC) concentration is a soil variable subject to changes. The management system is a key factor that influences these changes. To determine the long-term effects of the management system on SOC stocks (SOCS) in olive groves, 114 soil profiles were studied in the Los Pedroches Valley (Mediterranean rangelands - southern Spain) for 20 years. The management practices were conventional tillage (CT) and organic farming (OF) in four soil types: Cambisols (CMs), Regosols (RGs), Luvisols (LVs) and Leptosols (LPs). Soil properties were statistically analysed by management techniques, soil types and horizons. Significant differences (p < 0.05) were found between soil types and management practices. It was equally observed that the management system affected SOCS. In addition, the total SOCS during the 20-year experiment increased in OF with respect to CT by 72 and 66% in CMs and LVs respectively. SOC showed significant differences for horizons (p < 0.05) in relation to the management type. The stratification ratio (SR) was used as an indicator of soil quality based on the influence of surface SOC levels on erosion control, water infiltration and nutrient conservation with respect to deep layers. The SR of SOC from the surface to depth was greater in CT compared to OF with the exception of RGs. In all cases, the SR of SOC was >2. These results indicate high soil quality and that management practices affect SOC storage in the Los Pedroches Valley.

  20. Soil type recognition as improved by genetic algorithm-based variable selection using near infrared spectroscopy and partial least squares discriminant analysis

    PubMed Central

    Xie, Hongtu; Zhao, Jinsong; Wang, Qiubing; Sui, Yueyu; Wang, Jingkuan; Yang, Xueming; Zhang, Xudong; Liang, Chao

    2015-01-01

    Soil types have traditionally been determined by soil physical and chemical properties, diagnostic horizons and pedogenic processes based on a given classification system. This is a laborious and time consuming process. Near infrared (NIR) spectroscopy can comprehensively characterize soil properties, and may provide a viable alternative method for soil type recognition. Here, we presented a partial least squares discriminant analysis (PLSDA) method based on the NIR spectra for the accurate recognition of the types of 230 soil samples collected from farmland topsoils (0–10 cm), representing 5 different soil classes (Albic Luvisols, Haplic Luvisols, Chernozems, Eutric Cambisols and Phaeozems) in northeast China. We found that the PLSDA had an internal validation accuracy of 89% and external validation accuracy of 83% on average, while variable selection with the genetic algorithm (GA and GA-PLSDA) improved this to 92% and 93%. Our results indicate that the GA variable selection technique can significantly improve the accuracy rate of soil type recognition using NIR spectroscopy, suggesting that the proposed methodology is a promising alternative for recognizing soil types using NIR spectroscopy. PMID:26086823

  1. Mineral composition and charcoal determine the bacterial community structure in artificial soils.

    PubMed

    Ding, Guo-Chun; Pronk, Geertje Johanna; Babin, Doreen; Heuer, Holger; Heister, Katja; Kögel-Knabner, Ingrid; Smalla, Kornelia

    2013-10-01

    To study the influence of the clay minerals montmorillonite (M) and illite (I), the metal oxides ferrihydrite (F) and aluminum hydroxide (A), and charcoal (C) on soil bacterial communities, seven artificial soils with identical texture provided by quartz (Q) were mixed with sterilized manure as organic carbon source before adding a microbial inoculant derived from a Cambisol. Bacterial communities established in artificial soils after 90 days of incubation were compared by DGGE analysis of bacterial and taxon-specific 16S rRNA gene amplicons. The bacterial community structure of charcoal-containing soils highly differed from the other soils at all taxonomic levels studied. Effects of montmorillonite and illite were observed for Bacteria and Betaproteobacteria, but not for Actinobacteria or Alphaproteobacteria. A weak influence of metal oxides on Betaproteobacteria was found. Barcoded pyrosequencing of 16S rRNA gene amplicons done for QM, QI, QIF, and QMC revealed a high bacterial diversity in the artificial soils. The composition of the artificial soils was different from the inoculant, and the structure of the bacterial communities established in QMC soil was most different from the other soils, suggesting that charcoal provided distinct microenvironments and biogeochemical interfaces formed. Several populations with discriminative relative abundance between artificial soils were identified. PMID:23289489

  2. Relationship between fire temperature and changes in chemical soil properties: a conceptual model of nutrient release

    NASA Astrophysics Data System (ADS)

    Thomaz, Edivaldo L.; Doerr, Stefan H.

    2014-05-01

    The purpose of this study was to evaluate the effects of fire temperatures (i.e., soil heating) on nutrient release and aggregate physical changes in soil. A preliminary conceptual model of nutrient release was established based on results obtained from a controlled burn in a slash-and-burn agricultural system located in Brazil. The study was carried out in clayey subtropical soil (humic Cambisol) from a plot that had been fallow for 8 years. A set of three thermocouples were placed in four trenches at the following depths: 0 cm on the top of the mineral horizon, 1.0 cm within the mineral horizon, and 2 cm within the mineral horizon. Three soil samples (true independent sample) were collected approximately 12 hours post-fire at depths of 0-2.5 cm. Soil chemical changes were more sensitive to fire temperatures than aggregate physical soil characteristics. Most of the nutrient response to soil heating was not linear. The results demonstrated that moderate temperatures (< 400°C) had a major effect on nutrient release (i.e., the optimum effect), whereas high temperatures (> 500 °C) decreased soil fertility.

  3. Effect of Soil Moisture Content on the Splash Phenomenon Reproducibility

    PubMed Central

    Ryżak, Magdalena; Bieganowski, Andrzej; Polakowski, Cezary

    2015-01-01

    One of the methods for testing splash (the first phase of water erosion) may be an analysis of photos taken using so-called high-speed cameras. The aim of this study was to determine the reproducibility of measurements using a single drop splash of simulated precipitation. The height from which the drops fell resulted in a splash of 1.5 m. Tests were carried out using two types of soil: Eutric Cambisol (loamy silt) and Orthic Luvisol (sandy loam); three initial pressure heads were applied equal to 16 kPa, 3.1 kPa, and 0.1 kPa. Images for one, five, and 10 drops were recorded at a rate of 2000 frames per second. It was found that (i) the dispersion of soil caused by the striking of the 1st drop was significantly different from the splash impact caused by subsequent drops; (ii) with every drop, the splash phenomenon proceeded more reproducibly, that is, the number of particles of soil and/or water that splashed were increasingly close to each other; (iii) the number of particles that were detached during the splash were strongly correlated with its surface area; and (iv) the higher the water film was on the surface the smaller the width of the crown was. PMID:25785859

  4. Dynamics of Bacterial Communities in Two Unpolluted Soils after Spiking with Phenanthrene: Soil Type Specific and Common Responders

    PubMed Central

    Ding, Guo-Chun; Heuer, Holger; Smalla, Kornelia

    2012-01-01

    Considering their key role for ecosystem processes, it is important to understand the response of microbial communities in unpolluted soils to pollution with polycyclic aromatic hydrocarbons (PAH). Phenanthrene, a model compound for PAH, was spiked to a Cambisol and a Luvisol soil. Total community DNA from phenanthrene-spiked and control soils collected on days 0, 21, and 63 were analyzed based on PCR-amplified 16S rRNA gene fragments. Denaturing gradient gel electrophoresis (DGGE) fingerprints of bacterial communities increasingly deviated with time between spiked and control soils. In taxon specific DGGE, significant responses of Alphaproteobacteria and Actinobacteria became only detectable after 63 days, while significant effects on Betaproteobacteria were detectable in both soils after 21 days. Comparison of the taxonomic distribution of bacteria in spiked and control soils on day 63 as revealed by pyrosequencing indicated soil type specific negative effects of phenanthrene on several taxa, many of them belonging to the Gamma-, Beta-, or Deltaproteobacteria. Bacterial richness and evenness decreased in spiked soils. Despite the significant differences in the bacterial community structure between both soils on day 0, similar genera increased in relative abundance after PAH spiking, especially Sphingomonas and Polaromonas. However, this did not result in an increased overall similarity of the bacterial communities in both soils. PMID:22934091

  5. Comparative study on carbon accumulation in soils under managed and unmanaged forests in Central Balkan Mountains

    NASA Astrophysics Data System (ADS)

    Naydenova, Lora; Zhiyanski, Miglena; Leifeld, Jens

    2014-05-01

    Each soil has a carbon storage capacity, which depends on many factors including type of soil, vegetation, precipitation and temperature. The aim of this work is to compare the carbon accumulation in forest floor layers and mineral soil horizons under managed and unmanaged spruce and beech forest ecosystems developed on Cambisols in Central Balkan Mountains, Bulgaria. We have investigated two managed and two unmanaged forests - pure stands of European beech (Fagus sylvatica L.) and Norway spruce (Picea abies Karst.). In each experimental site one representative soil profile was prepared with additional 4 sampling profiles for more precise determination of spatial variability of soil characteristic at site level. The forest floor was sampled in 3 repetitions per site, by a plastic frame (25:25 cm). The textural composition of soil, bulk density, coarse fraction content, pH, carbon and nitrogen content were analysed for forest floor layers and soil at different soil depths (0-10 cm, 10-20 cm, 20-30 cm and 30-50 cm). Both European beech and Norway spruce stands had higher accumulation of organic matter in the forest floor and the Ah horizon under unmanaged conditions. When managed, carbon contents tended to be higher in deeper horizons of the mineral soil, probably due to differences in microclimate after cutting. However, the variability in carbon storage was higher in managed sites which may reflect a higher degree of disturbance. Further work will analyse the soil carbon dynamics using radiocarbon as a tracer.

  6. Una Guia para Los Padres sobre La Educacion Especial: El Derecho de Su Hijo(a) a Adquirir una Educacion en el Estado de Nueva York (A Parent's Guide to Special Education: Your Child's Right to an Education in New York State).

    ERIC Educational Resources Information Center

    New York State Education Dept. Albany. Office for the Education of Children with Handicapping Conditions.

    This guide provides information to help parents of special needs children in New York become active partners in the planning and implementation of special education programs. The first part of the guide provides in-depth information related to the special education process in New York State public schools. A historical view of children's rights to…

  7. Efectos Especiales de Anclaje (Estudio sobre Regresiones de Juicios Condicionales). Parte 1: Distincion entre Efectos Aditivos y Efectos Multiplicativos en el Fenomeno de Anclaje (Special Effects of Anchoring (Study on Regression of Conditional Judgements) Part 1: Distinction Between Additive Effects and Multiplicative Effects in the Phenomenon of Anchoring). Publication No. 17.

    ERIC Educational Resources Information Center

    Lopez Alonso, A. O.

    A linear relationship was found between judgements given by 160 subjects to 7 objects presented as single stimuli (alpha judgements) and judgements given to the same objects presented with a condition (gamma judgements). This relationship holds for alpha judgements and the gamma judgements that belong to a family of constant stimulus and varying…

  8. What Providers Should Know about Child Care Assistance for Families: A Targeted Effort to Reach Hispanic Families and Providers = Lo que Deben Saber los Proveedores Sobre el Programa de Ayuda de Cuidado Infantil para las Familias: Un Esfuerzo Especial para Alcanzar Familias y Proveedores Hispanos

    ERIC Educational Resources Information Center

    Child Care Bureau, 2004

    2004-01-01

    Federal and State governments can help families pay for child care. The families one serves may be eligible for this assistance, and one may receive this funding for services one provides, thus becoming a "participating provider." This paper provides answers to the following questions: (1) How can parents receive child care assistance?; (2) How do…

  9. "Estudia para que no te pase lo que a mi": Narrativas Culturales Sobre el Valor de la Escuela en Familias Mexicanas ("Study So That What Happened to Me Doesn't Happen to You": Cultural Narratives about the Value of Schooling in Mexican Families).

    ERIC Educational Resources Information Center

    Ramos, Claudia Saucedo

    2003-01-01

    Narratives used by parents in Mexican working-class families to motivate their children to study are examined for the advice offered and parental attitudes about the importance of school. The integration of contemporary pressures about the value of schooling is investigated, as well as the ways in which the value of schooling is being…

  10. Que Tal la Justicia Social en los Alumnos de la UIA (Universidad Iberoamericana)? Investigacion sobre los Logros en la Formacion Valoral (What about Social Justice among the Students of the Iberoamerican University? Survey on the Achievements in the Acquisition of Values).

    ERIC Educational Resources Information Center

    Bazdresch Parada, Juan E.

    This survey investigates how the students of social philosophy modify their criteria on basic questions of social justice. A questionnaire of 30 questions, with 5 options, was developed. The five answer/options correspond to the following five schools of social philosophy (five ways of thinking): (1) liberal individualism; (2) humanitarianism; (3)…

  11. Identity-Forming Discourses: A Critical Discourse Analysis on Policy Making Processes Concerning English Language Teaching in Colombia (Discursos que forjan identidades: un análisis crítico de discursos en la formulación de políticas sobre la enseñanza del inglés en Colombia)

    ERIC Educational Resources Information Center

    Escobar Alméciga, Wilder Yesid

    2013-01-01

    This article addresses a critical problem about asymmetrical power relationships and uneven conditions in English language education exerted via identity shaping discourses in the document Educación: "Visión 2019" issued by the Colombian Ministry of National Education. The study follows the critical discourse analysis method. It…

  12. Lo que los educadores necesitan saber sobre...El agrupamiento por habilidad [y] La compactacion del curriculum [y] Los alumnos dotados y el aprendizaje cooperativo [y] La actividad tutoral. Guias practica (What Educators Need To Know about...Ability Grouping [and] Curriculum Compacting [and] Gifted Students and Cooperative Learning [and] Mentoring. Practitioners' Guides).

    ERIC Educational Resources Information Center

    Siegle, Del, Ed.

    These four pamphlets in Spanish offer guidelines supported by theory-driven quality research that is problem-based, practice-relevant, and consumer-oriented. Each pamphlet has a section summarizing research from the literature or topic notes as well as implications for the classroom. The first guide offers principles for teachers concerning the…

  13. Proyecto Curricular Sobre la Herencia Iberoamericana. Latinos en la Formacion de los Estados Unidos de American: Ayer, Hoy y Manana. Procedimientos de la Conferencia Sequnda Conferencia Anual del Panel Consultivo Internacional en Santillana del Mar, Espana (The Ibero-American Heritage Curriculum Project. Latinos in the Making of the United States of America: Yesterday, Today, and Tomorrow).

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany.

    The Ibero-American Heritage Curriculum Project is an interdisciplinary curriculum development project designed to integrate the study of Ibero-American heritage and culture into classroom instructional programs, kindergarten through grade 12. The project was initiated by the New York State Education Department and involves the Spanish National…

  14. Using Case Study Methodology to Approach the Views of Teachers of English on Classroom Disciplinary Strategies (Uso de la metodología de estudio de casos para aproximarse a las concepciones de profesores de inglés sobre las estrategias disciplinarias en el aula)

    ERIC Educational Resources Information Center

    Díaz Larenas, Claudio

    2012-01-01

    This qualitative study aims at identifying the disciplinary strategies claimed to be used by a group of five secondary classroom teachers of English in public or semi-public schools in Chile. To conduct this research, a semi-structured interview was applied to participants. The data were analyzed using the principles of semantic content analysis…

  15. El juego entre el nacimiento y los 7 anos: Un manual para ludotecarias. Investigacion-accion sobre la Familia y la Primera Infancia. UNESCO Sector de Educacion Monografia (Play between Birth and 7 Years: A Manual for Preschool Teachers. Action Research in Family and Early Childhood. UNESCO Education Sector Monograph).

    ERIC Educational Resources Information Center

    Grellet, Carolina

    The purpose of this Spanish-language manual is to help preschool teachers better understand theoretical concepts related to children's play. Following a preface that discusses UNESCO's activities related to early childhood education, the two main sections of the manual discuss children's play between 0-2 years and 2-7 years. Each section includes…

  16. [The EMECAM protocol: an analysis of the short-term effect of air pollution on mortality. Estudio Multicéntrico Español sobre la Relación entre la Contaminación Atmosférica u la Mortalidad].

    PubMed

    Pérez-Hoyos, S; Sáez Zafra, M; Barceló, M A; Cambra, C; Figueiras Guzmán, A; Ordóñez, J M; Guillén Grima, F; Ocaña, R; Bellido, J; Cirera Suárez, L; López, A A; Rodríguez, V; Alcalá Nalvaiz, T; Ballester Díez, F

    1999-01-01

    The aim of this study is to Mortality show the protocol of analysis which was set out as part of the EMECAM Project, illustrating the application thereof to the effect of pollution has on the mortality in the city of Valencia. The response variables considered will be the daily deaths rate resulting from all causes, except external ones. The explicative variables are the daily series of different pollutants (black smoke, SO2, NO2, CO, O3). As possible confusion variables, weather factors, structural factors and weekly cases of flu are taken into account. A Poisson regression model is built up for each one of the four deaths series in two stages. In the first stage, a baseline model is fitted using the possible confusion variables. In the second stage, the pollution variables or the time legs thereof are included, controlling the residual autocorrelation by including mortality time lags. The process of fitting the baseline model is as follows: 1) Include the significant sinusoidal terms up to the sixth order. 2) Include the significant temperature or temperature squared terms with the time lags thereof up to the 7th order. 3) Repeat this process with the relative humidity. 4) Add in the significant terms of calendar years, daily tendency and tendency squared. 5) The days of the week as dummy variables are always included in the model. 6) Include the holidays and the significant time lags of up to two weeks of flu. Following the reassessment of the model, each one of the pollutants and the time lags thereof up to the fifth order are proven out. The impact is analyzed by six-month periods, including interaction terms. PMID:10410600

  17. Human Relations Activities for the Single Parent To Develop More Effective Parent/Child Relations. Bilingual Guide = Actividades sobre relaciones humanas para ayudar al padre-soltero o madre-soltera a desarrollar una relacion efectiva entre padre e hijo Guia bilingue.

    ERIC Educational Resources Information Center

    Peterson, Susan

    Written in English and Spanish, this bilingual guide offers 10 activities which single parents can use to improve their relationships with their children. Objectives of activities include: (1) developing children's responsibility for work tasks in the home; (2) improving sibling relationships; (3) discussing emergencies with children; (4)…

  18. Viviremos! On the Road to Healthy Living: A Bilingual Curriculum on AIDS and HIV Prevention for Migrant Students (Grades 6-12) = El Camino Hacia la Salud: Un Programa de Estudio Bilingue sobre la Prevencion del SIDA y del VIH para Estudiantes Migrantes (Grados 6-12).

    ERIC Educational Resources Information Center

    VAMOS (Villarreal Analytical Management and Organizational Services), San Marcos, TX.

    This curriculum provides the basic information everyone needs to avoid HIV infection, but was specifically designed for Latino farmworker students in grades 6-7. The student materials are written in Spanish and English and may be used with older student or young adults, or in English-as-a-second-language courses. An introduction provides…

  19. Mirando al Futuro del Desarrollo Humano en America Latina y el Caribe. Seminario Regional sobre Universalization de la Educacion (Sucre, Bolivia, 4-10 mayo 1987) (Looking at the Future of Human Development in Latin America and the Caribbean. Regional Seminar on the Universalization of Education [Sucre, Bolivia, May 4-10, 1987]).

    ERIC Educational Resources Information Center

    United Nations Children's Fund, Santiago (Chile). Oficina Regional para les Americas.

    One of every two children in developing nations does not complete primary school and four out of ten adults do not read or write. Of these ten, six are women. There were 44 million illiterate adults in Latin America in 1985, and of the 66 million school age children, 8.5 million were not in school. Thirty million of these children lived in…

  20. Consulta regional sobre investigacion en educacion y toma de decisiones en America Latina: Informe final (Lima, Peru, 11-15 de mayo de 1987) (Regional Meeting on Research in Education and Decision Making in Latin America: Final Report [Lima, Peru, May 11-15, 1987]).

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Santiago (Chile). Regional Office for Education in Latin America and the Caribbean.

    This report presents the highlights of a United Nations Educational, Scientific, and Cultural Organization (UNESCO) conference that was convened to give impetus to and encourage research programs, to analyze research policy formation, and to establish research priorities in the field of educational planning and administration. The document…

  1. Lo que los Padres Necesitan Saber sobre...Reconocer y Animar los Intereses, las Capacidades, y los Talentos de los Ninos Dotados de la Escuela Primaria. Guia Practica B0213 (What Parents Need To Know about...Recognizing and Encouraging Interests, Strengths, and Talents of Gifted Elementary School Children. Practitioners' Guide B0213).

    ERIC Educational Resources Information Center

    Delcourt, Marcia A. B.

    This brochure, written in Spanish, discusses strategies that Spanish-speaking parents can use to support the interests of their children and how to recognize and extend their children's talents. Parents are urged to: (1) be aware of what their child likes to do and be patient with the changing patterns as the child explores areas of interests and…

  2. Lo Que los Padres Necesitan Saber sobre...Reconocer y Animar los Intereses, las Capacidades, y los Talentos de los Ninos Dotados Jovenes. Guia Practica B0212 (What Parents Need To Know about...Recognizing and Encouraging Interests, Strengths, and Talents of Young Gifted Children. Practitioners' Guide B0212).

    ERIC Educational Resources Information Center

    Delcourt, Marcia A. B.

    This pamphlet, written in Spanish, is designed to help Spanish-speaking parents recognize and encourage their gifted preschool children. It begins by discussing some of the interests of very young children and lists strategies for facilitating and supporting those interests, including: provide the child with opportunities to find out about a…

  3. Lo Que los Padres Necesitan Saber sobre...Reconocer y Animar los Intereses, las Capacidades, y los Talentos de los Adolescentes. Guia Practica B0214 (What Parents Need To Know about...Recognizing Interests, Strengths, and Talents of Gifted Adolescents. Practitioners' Guide B0214).

    ERIC Educational Resources Information Center

    Delcourt, Marcia A. B.

    This brochure, written in Spanish, for Spanish-speaking parents of gifted adolescents discusses strategies to use to support the interests of their children and how to recognize and extend their children's talents. Parents are urged to: (1) increase their knowledge about the child's areas of interest; (2) discuss the child's present and future…

  4. ...And That's How It All Began: Putting Information about Your Child's Growth, Health and Safety All within Your Reach...Because the First Years Last Forever! = ...Y asi es como empezo todo: Ponemos a su alcance en forma conjunta la informacion sobre el crecimiento, la salud y la seguridad de su hijo...Porque los primeros anos duran para siempre!

    ERIC Educational Resources Information Center

    North Carolina Partnership for Children, Raleigh.

    Smart Start is North Carolina's model early childhood initiative to help all North Carolina children enter school healthy and prepared for success. This resource guide, in Spanish and English versions, is designed to provide parents with information on infant and child development, health care, and resources for further assistance. Presented in an…

  5. Consejos para los Padres Sobre la Lectura: Informacion e Ideas para Ayudar a los Ninos Desde la Infancia Hasta Octavo Grado a Tener Exito en la Lectura (Tips for Parents about Reading: Information and Ideas for Helping Children through Grade Eight Succeed with Reading).

    ERIC Educational Resources Information Center

    Davis, Deborah; Lewis, Jan Patricia

    Noting that all parents want the best school experience for their children, this booklet, in Spanish, gives parents some ideas about what to expect at different ages and stages of reading development, suggestions for what parents can do at home, and a list of favorite books parents can find in most libraries for parents and children to read.…

  6. The Role of English Pre-Service Teachers' Beliefs about Teaching in Teacher Education Programs (El papel de las creencias de los profesores de inglés en formación sobre la enseñanza en los programas de formación docente)

    ERIC Educational Resources Information Center

    Castellanos Jaimes, Judith

    2013-01-01

    This paper presents a review of studies on pre-service teachers' beliefs about teaching. The purpose of the article is to show teacher educators the relevance of exploring such issue in the classroom. Preservice teachers come into the teaching profession with beliefs about teaching; sometimes they are aware of them, other times they are not. The…

  7. Tabla de Especificaciones e Instructivo sobre Elaboracion de Pruebas Objetivas en la Ensenanza Primaria, para las asignaturas de Estudios Sociales, Idioma Espanol, Matematicas y Ciencias Naturales (Specification Tables and Instructions for the Construction of Objective Tests in the Primary Grades in Social Studies, Spanish, Mathematics, and Natural Sciences).

    ERIC Educational Resources Information Center

    Ministerio de Educacion, Guatemala City (Guatemala). Direccion de Bienestar Estudiantil y Educacion Especial.

    This booklet presents specification tables illustrating the relative importance given to topics on tests within a particular subject area. The general subject areas are social studies, Spanish, mathematics, and natural sciences. Tables are provided for final exams in each of these areas for several primary grades, illustrating the importance of…

  8. How To Talk to Your Doctor (and Get Your Doctor To Talk to You!). An Educational Workshop on Doctor Patient Communication = Como Hablarle a su Doctor (iY que su doctor le hable a usted!). Un seminario educativo sobre la comunicacion entre el doctor y el paciente.

    ERIC Educational Resources Information Center

    Baylor Coll. of Medicine, Houston, TX.

    This workshop, written in both English and Spanish, focuses on improving communication between physician and patient. In the workshop, the trainers will talk about "building bridges" between patient and doctor by understanding the doctor's role and his/her duty to the patient. According to the workshop, a person's doctor should communicate…

  9. Novice Non-Native English Teachers' Reflections on Their Teacher Education Programmes and Their First Years of Teaching (Reflexiones de profesores novatos y no nativos del inglés sobre sus programas de formación y sus primeros años de instrucción)

    ERIC Educational Resources Information Center

    Akcan, Sumru

    2016-01-01

    This study investigates novice non-native English teachers' opinions about the effectiveness of their teacher education programme and the challenges during their initial years of teaching. The results of a survey administered to fifty-five novice teachers and follow-up interviews identify strengths and weaknesses in their teacher education…

  10. Vínculos sobre um modelo de quartessência de Chaplygin usando observações do satélite chandra da fração de massa de gás em aglomerados de galáxias

    NASA Astrophysics Data System (ADS)

    de Souza, R. S.

    2003-08-01

    Observações de Supernovas do tipo Ia mostram que a expansão do Universo está acelerando. Segundo as equações de Einstein uma componente com pressão negativa (energia escura) é necessária para explicar a aceleração cósmica. Além da energia escura é usualmente admitido que no Universo há também uma matéria exótica com pressão zero, que é chamada de matéria escura. Essa componente possui um papel fundamental na formação de estruturas no Universo. Recentemente tem se explorado a possibilidade de que matéria e energia escura poderiam ser unificadas através de uma única componente, que tem sido denominada de quartessência. Um exemplo de fluido com essas características é o Gás de Chaplygin Generalizado, que possui uma equação de estado da forma p = -A/ra. Inicialmente consideramos o caso especial a = 1 (gás de Chaplygin) e vinculamos parâmetros do modelo utilizando observações em raios-X do satélite Chandra da fração de massa de gás em aglomerados de galáxias. Uma comparação dos vínculos obtidos com esse teste com outros testes, tais como supernovas e idade do Universo, mostra que esse teste é bastante restritivo. Exibiremos ainda resultados para o caso em que a curvatura é nula e o parâmetro a está compreendido no intervalo -1 < a 1.

  11. Students and Teachers' Reasons for Using the First Language within the Foreign Language Classroom (French and English) in Central Mexico (Razones de alumnos y maestros sobre el uso de la primera lengua en el salón de lenguas extranjeras (francés e inglés) en el centro de México)

    ERIC Educational Resources Information Center

    Mora Pablo, Irasema; Lengeling, M. Martha; Rubio Zenil, Buenaventura; Crawford, Troy; Goodwin, Douglas

    2011-01-01

    The present study explores the use of the first language in a context of foreign language teaching. This qualitative research presents the classroom practice and points of view of French and English teachers and students within a public educational institute in central Mexico using the techniques of questionnaires and semi-structured interviews.…

  12. Lo que Piensan los Estudiantes y Profesores Sobre la Calidad de la Educacion Superior. Estudio Comparativo en 5 Instituciones de Educacion Superior--dos publicas y tres privadas--en Guadalajara, Jalisco, Mexico (What Students and Faculties Think about the Quality of Higher Education. Comparative Study of 5 Higher Education Institutions--Two Public and Three Private--in Guadalajara, Jalisco, Mexico).

    ERIC Educational Resources Information Center

    Yanez, Maria Lorena Hernandez

    This study, written in Spanish, compared attitudes of students (N=302) and faculty (N=28) at five institutions of higher education (two public and three private) in Guadalajara, Jalisco, Mexico. The study explored first, whether respondents believed there are significant quality differences between private and public universities and, second, what…

  13. Exploring EFL Pre-Service Teachers' Experience with Cultural Content and Intercultural Communicative Competence at Three Colombian Universities (Indagación sobre la experiencia con el contenido cultural y la competencia comunicativa intercultural de docentes de inglés en formación, en tres universidades colombianas)

    ERIC Educational Resources Information Center

    Olaya, Alba; Gómez Rodríguez, Luis Fernando

    2013-01-01

    This article reports the findings of a qualitative research project that explored pre-service English teachers' perceptions of and attitudes toward the aspects of culture and intercultural competence addressed in their English classes in the undergraduate programs at three Colombian universities. Findings reveal that pre-service teachers are…

  14. Algunas Premisas Metodologicas y Conceptuales sobre el Desarrollo de los Movimientos en el Primer Ano de Vida (0-12 Meses) (Some Methodological and Conceptual Premises about the Development of Movement in the First Year of Life (0-12 Months)).

    ERIC Educational Resources Information Center

    Bequer Diaz, Gladys

    1997-01-01

    Examined the emergence of principal and secondary movements in Cuban children in their first year of life. Based on 35 examples of observed movements, an integrated program of activity is developed to assist in the development of physical skills which are essential to the development of a well-rounded personality. (AS)

  15. Attending School and Learning or Repeating and Leaving. A Study about the Determinants of Grade Repetition and Dropout in Primary School in Honduras. Synthesis of the Study = Asistir y Aprender o Repetir y Desertar. Un Estudio sobre los Factores que Contribuyen a la Repitencia en la Escuela Primaria en Honduras. Sintesis del Informe.

    ERIC Educational Resources Information Center

    McGinn, Noel F.; And Others

    This paper synthesizes a study designed to identify the factors that contribute to primary school repetition and dropout in Honduras. Data were collected by record reviews; teacher, student, and parent interviews; and a test of Spanish. The sample included 1,253 students in grades 1 and 3 in 40 schools in rural Honduras. The main findings of the…

  16. Manual for ERLE (Energy-Related Laboratory Equipment). Instructions and information for institutions of higher learning concerning used energy-related laboratory equipment grants; Manual para ERLE [Equipo de Laboratorio Relacionado con la Energia]. Instrucciones e informacion para instituciones de educacion superior sobre subvenciones de equipo de laboratorio usado relacionado con la energia

    SciTech Connect

    Not Available

    1994-10-01

    This is a listing of energy related equipment available through the Energy-Related Laboratory Equipment Grant Program which grants used equipment to institutions of higher education for energy-related research. Information included is an overview of the program, how to apply for a grant of equipment, eligibility requirements, types of equipment available, and the costs for the institution.

  17. Educacion, Salud y Bienestar para el Nino Preescolar y la Familia. (5 de Enero--28 de Febrero, 1997) Informe Curso sobre (Education, Health, and Well-Being of Preschool Children and the Family. January 5 - February 28, 1997. Report of a Course).

    ERIC Educational Resources Information Center

    Golda Meir Mount Carmel International Training Centre, Haifa (Israel).

    This report describes a course held in Spanish at the Golda Meir Mount Carmel International Training Center in Haifa, Israel. The course considered various themes related to the education, health, and well-being of preschool children. Participants were 30 individuals from Central and South American countries who held decision-making positions in…

  18. Una guia para los padres sobre lo mas importante: el logro academico plan de educacion de Maryland desde preescolar hasta el 12 grado, 2002-2003. (A Parent's Guide to Achievement Matters Most: Maryland's Plan for PreK-12 Education, 2002-2003).

    ERIC Educational Resources Information Center

    Maryland State Dept. of Education, Baltimore.

    To raise the achievement of every student in the state, Maryland implemented "Achievement Matters Most," a new plan for public elementary and secondary schools that sets goals in the areas of achievement, teaching, testing, safety, and family involvement in schools. This Spanish-language guide for parents outlines the goals and characteristics of…

  19. Efectos Especiales de Anclaje (Estudio sobre Regresiones de Juicios Condicionales). Parte 2: Invariancia del Juicio No-Condicional Como Valor Estandar Para el Juicio Condicional (Special Effects of Anchoring (Study of Regression of Conditional Judgements) Part 2: Invariance of Unconditional Judgments as Standard Value for the Conditional Judgment). Publication No. 31.

    ERIC Educational Resources Information Center

    Lopez Alonso, A. O.

    From the best-fit lines corresponding to sets of families of conditional judgements, the constant stimulus family and the constant condition family, both defined for a same scale object, the coordinate values of the point of intersection of both lines (indifference point) are obtained. These values are studied in relation to the mean values of the…

  20. Los Hispanos: Problemas y Oportunidades. Resumen de la Actual Situacion Demografica, Economica, Social y Politica de los Hispanos en los Estados Unidos y de las Iniciativas Tomadas por la Fundacion Ford Para Hacer Frente a las Necesidades de esta Poblacion en Aumento y Determinar sus Efectos Sobre la Sociedad Estadounidense. Documento de Trabajo de la Fundacion Ford, No. 436.

    ERIC Educational Resources Information Center

    Ford Foundation, New York, NY.

    The Hispanic population's growing impact on American society has caused the Ford Foundation to explore new Foundation initiatives. The 1980 census revealed 14.6 million Hispanics: 60% Mexican American; 14% Puerto Rican; 6% Cuban, and 20% Other. The Hispanic population in the United States is growing and is characterized by diversity; rapid growth…

  1. Exploring Conceptions about Writing and Learning: Undergraduates' Patterns of Beliefs and the Quality of Academic Writing (Acercamiento a las concepciones sobre la escritura y el aprendizaje: patrones de creencias de los universitarios y la calidad de su redacción académica)

    ERIC Educational Resources Information Center

    Martínez-Fernández, J. R.; Corcelles, M.; Bañales, G.; Castelló, M.; Gutiérrez-Braojos, C.

    2016-01-01

    Introduction: In this study, the conceptions of learning and writing of a group of undergraduates enrolled in a teacher education programme were identified. The relationship between them were analysed, and a set of patterns of beliefs about learning and writing were defined. Finally, the relation between these patterns and the quality of a text…

  2. Instantánea del cáncer de riñón

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de riñón; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  3. Prevención del cáncer de ovario (PDQ®)—Versión para pacientes

    Cancer.gov

    Sumario de información revisada por expertos sobre factores que pueden influir en el riesgo de presentar cáncer de ovario, de trompas de Falopio y primario de peritoneo y sobre las investigaciones dirigidas a prevenir los mismos.

  4. Instantánea del melanoma

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el melanoma; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  5. 76 FR 34296 - Proposed Collection; Comment Request for Forms 1040-PR and 1040-SS

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-13

    ... para la Declaraci n de la Contribuci n Federal sobre el Trabajo por Cuenta Propia (Incluyendo el Cr... para la Declaraci n de la Contribuci n Federal sobre el Trabajo por Cuenta Propia (Incluyendo el Cr... collection techniques or other forms of information technology; and (e) estimates of capital or...

  6. 77 FR 72268 - Rules Relating to Additional Medicare Tax

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-05

    ... associated with the proposed collection of information; and Estimates of capital or start-up costs and costs... Declaraci n de la Contribuci n Federal sobre el Trabajo por Cuenta Propia (Incluyendo el Cr dito Tributario... Declaraci n de la Contribuci n Federal sobre el Trabajo por Cuenta Propia (Incluyendo el Cr dito...

  7. Calcio y la prevención del cáncer

    Cancer.gov

    Hoja informativa que resume los resultados de estudios sobre el calcio y la prevención del cáncer. Incluye información sobre las recomendaciones dietéticas para calcio y la cantidad de calcio en los alimentos y en complementos de calcio.

  8. Terapia hormonal para la menopausia y el cáncer

    Cancer.gov

    Hoja informativa acerca de los resultados de los estudios sobre el uso de la terapia hormonal para la menopausia. Incluye información sobre el efecto de esta terapia en el cuerpo y explica los riesgos y beneficios del uso de hormonas.

  9. Instantánea del cáncer de seno (mama)

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de seno (mama); así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  10. Instantánea de los cánceres de hígado

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre los cánceres de hígado y de las vías biliares; así como ejemplos de actividades del NCI y adelantos en la investigación de estos tipos de cáncer.

  11. Prevención del cáncer de estómago (gástrico) (PDQ®)—Versión para pacientes

    Cancer.gov

    Sumario de información revisada por expertos sobre factores que pueden influir en el riesgo de presentar cáncer de estómago y sobre las investigaciones dirigidas a la prevención de esta enfermedad.

  12. Instantánea del cáncer de tiroides

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de tiroides; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  13. Instantánea del cáncer de vejiga

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de vejiga; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  14. Neuropatía periférica inducida por quimioterapia

    Cancer.gov

    Artículo sobre un efecto secundario de la quimioterapia que causa dolor y malestar en las manos y los pies. También incluye información sobre los esfuerzos para mejorar las opciones de detección, tratamiento y prevención.

  15. Instantánea del sarcoma de Kaposi

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el sarcoma de Kaposi; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  16. Instantánea del linfoma

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el linfoma; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  17. Prevención del cáncer de ovario, trompas y peritoneo (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Sumario de información revisada por expertos sobre factores que influirían en el riesgo de presentar cáncer de ovario, de trompas de Falopio y primario de peritoneo y sobre las investigaciones dirigidas a la prevención de los mismos.

  18. Hacer frente - Obtener cuidados médicos de seguimiento

    Cancer.gov

    Información sobre los cuidados médicos de seguimiento después del tratamiento del cáncer. Trata sobre su plan de cuidados de seguimiento, cómo obtener un plan para el bienestar e incluye una guía para una vida saludable.

  19. Instantánea del mieloma

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el mieloma; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  20. Instantánea del cáncer de pulmón

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de pulmón; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  1. Control del dolor: Apoyo para las personas con cáncer

    Cancer.gov

    Contiene información sobre las medicinas contra el dolor para pacientes con cáncer, los planes para controlarlo, cómo hablar con su equipo de atención médica sobre el dolor que usted siente y qué hacer para controlar los efectos físicos y emocionales del

  2. Instantánea del cáncer de páncreas

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de páncreas; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  3. Instantánea de los cánceres de cabeza y cuello

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre los cánceres de cabeza y cuello; así como ejemplos de actividades del NCI y adelantos en la investigación de estos tipos de cáncer.

  4. Instantánea del cáncer de cuello uterino

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de cuello uterino; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  5. Prevención del cáncer de cavidad oral y orofaringe (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Sumario de información revisada por expertos sobre factores que pueden influir en el riesgo de presentar cáncer de labio, cavidad oral y orofaringe, y sobre las investigaciones dirigidas a la prevención de esta enfermedad.

  6. Instantánea de los cánceres de cerebro y del sistema nervioso central

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre los cánceres de cerebro y del sistema nervioso central; así como ejemplos de actividades del NCI y adelantos en la investigación de estos tipos de cáncer.

  7. Prevención del cáncer de estómago (gástrico) (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Sumario de información revisada por expertos sobre factores que pueden influir en el riesgo de presentar cáncer de estómago y sobre las investigaciones dirigidas a la prevención de esta enfermedad.

  8. Instantánea del cáncer de esófago

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de esófago; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  9. Instantánea del cáncer colorrectal

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer colorrectal; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  10. Instantánea del cáncer de estómago

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de estómago; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  11. Capacitación del personal y de los pacientes en torno a los cuidados terminales

    Cancer.gov

    Artículo sobre programas innovadores de base científica para ayudar a médicos y pacientes a hablar sobre la transición de un tratamiento activo para el cáncer a los cuidados en la etapa final de la vida.

  12. Instantánea del cáncer de ovario

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de ovario; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  13. Instantánea del cáncer de endometrio

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de endometrio; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  14. Instantánea del cáncer de próstata

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el cáncer de próstata; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  15. Instantánea del sarcoma

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre el sarcoma; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  16. Instantánea de la leucemia

    Cancer.gov

    Información sobre las tendencias de incidencia, mortalidad y financiamiento del NCI sobre la leucemia; así como ejemplos de actividades del NCI y adelantos en la investigación de este tipo de cáncer.

  17. The creation of a digital soil map for Cyprus using decision-tree classification techniques

    NASA Astrophysics Data System (ADS)

    Camera, Corrado; Zomeni, Zomenia; Bruggeman, Adriana; Noller, Joy; Zissimos, Andreas

    2014-05-01

    classes with a success percentage included between 88% (calcaric fluvic Cambisols and vertic Cambisols) and 96% (skeletric calcaric Regosols and calcaric lithic Leptosols). In a parallel study, characteristic profiles are assigned to every soil class. The soil classes will be field checked with mapped and unmapped areas including points with new soil properties. This study is part of the AGWATER project (AEIFORIA/GEORGO/0311(BIE)/06), co-financed by the European Regional Development Fund and the Republic of Cyprus through the Research Promotion Foundation. Cohen, D.R., Rutherford, N.F., Morisseau, E., and Zissimos, A.M.: Geochemical Atlas of Cyprus. Sydney: UNSW Press; 2011. McBratney, A.B., Mendonça Santos, M.L., and Minasny, B.: On digital soil mapping. Geoderma 117, 3-52, 2003 Noller, J.: The Geomorphology of Cyprus. Cyprus Geological Survey, Open File Report, 269 p, 2009.

  18. The Italian contribution to the World Soils Book Series: The Soils of Italy

    NASA Astrophysics Data System (ADS)

    Costantini, Edoardo; Dazzi, Carmelo

    2015-04-01

    Passing to the age of "Anthropocene", man has forgotten the ancient bond that ties him to the soil, and turning from "homo sapiens" to "homo technologicus" he has stopped considering how much his well-being and the quality of life on Earth are fundamentally linked to the quality of soils. Yet today, as never before, maintaining the quality of soils is of paramount relevance for the sustainable development of humanity. Unfortunately, as soils are a crypto-resource, not many lay-people recognize its importance in the biosphere equilibrium and, unfortunately, seldom consider it among the environmental resources that must be protected! To fill such a gap in knowledge, the Springer editor, under the leading of professor Alfred Hartemink, has published the World Soils Book Series, whose aim is to spread the knowledge on the soils in a particular country in a concise and highly reader-friendly way. The volume "The Soils of Italy" belongs to this international series of books. Its ambitious goals are to establish a broad base for the knowledge of the soils of Italy, and to give useful information on i) their characteristics, diffusion and fertility, ii) the main threats they are subjected, and iii) the future scenarios of relationships between soil sciences and the disciplines, which are not traditionally linked to the world of agriculture, such as urban development, medicine, economics, sociology, archaeology. In Italy there is about 75% of the global pedodiversity. A vast majority of the WRB reference soil groups (25 out of 32), as well as soil orders of Soil Taxonomy (10 out of 12) are represented in the main Italian soil typological units (STUs). More than a fourth of STUs belongs to Cambisols, more than a half to only four reference soil groups (Cambisols, Luvisols, Regosols, Phaeozems), and 88% to nine RSGs (the former plus Calcisols, Vertisols, Fluvisols, Leptosols, and Andosols), while the remaining 16 RSGs are represented in 12% of STUs. The clear skewness and

  19. Effect of soil type and soil management on soil physical, chemical and biological properties in commercial organic olive orchards in Southern Spain

    NASA Astrophysics Data System (ADS)

    Gomez, Jose Alfonso; Auxiliadora Soriano, Maria; Montes-Borrego, Miguel; Navas, Juan Antonio; Landa, Blanca B.

    2014-05-01

    One of the objectives of organic agriculture is to maintain and improve soil quality, while simultaneously producing an adequate yield. A key element in organic olive production is soil management, which properly implemented can optimize the use of rainfall water enhancing infiltration rates and controlling competition for soil water by weeds. There are different soil management strategies: eg. weed mowing (M), green manure with surface tillage in spring (T), or combination with animal grazing among the trees (G). That variability in soil management combined with the large variability in soil types on which organic olive trees are grown in Southern Spain, difficult the evaluation of the impact of different soil management on soil properties, and yield as well as its interpretation in terms of improvement of soil quality. This communications presents the results and analysis of soil physical, chemical and biological properties on 58 soils in Southern Spain during 2005 and 2006, and analyzed and evaluated in different studies since them. Those 58 soils were sampled in 46 certified commercial organic olive orchards with four soil types as well as 12 undisturbed areas with natural vegetation near the olive orchards. The four soil types considered were Eutric Regosol (RGeu, n= 16), Eutric Cambisol (CMeu, n=16), Calcaric Regosol (RGca, n=13 soils sampled) and Calcic Cambisol (CMcc), and the soil management systems (SMS) include were 10 light tillage (LT), 16 sheep grazing (G), 10 tillage (T), 10 mechanical mowing (M), and 12 undisturbed areas covered by natural vegetation (NV-C and NV-S). Our results indicate that soil management had a significant effect on olive yield as well as on key soil properties. Among these soil properties are physical ones, such as infiltration rate or bulk density, chemical ones, especially organic carbon concentration, and biological ones such as soil microbial respiration and bacterial community composition. Superimpose to that soil

  20. Nutrient uptake by agricultural crops from biochar-amended soils: results from two field experiments in Austria

    NASA Astrophysics Data System (ADS)

    Karer, Jasmin; Zehetner, Franz; Kloss, Stefanie; Wimmer, Bernhard; Soja, Gerhard

    2013-04-01

    The use of biochar as soil amendment is considered as a promising agricultural soil management technique, combining carbon sequestration and soil fertility improvements. These expectations are largely founded on positive experiences with biochar applications to impoverished or degraded tropical soils. The validity of these results for soils in temperate climates needs confirmation from field experiments with typical soils representative for intensive agricultural production areas. Frequently biochar is mixed with other organic additives like compost. As these two materials interact with each other and each one may vary considerably in its basic characteristics, it is difficult to attribute the effects of the combined additive to one of its components and to a specific physico-chemical parameter. Therefore investigations of the amendment efficacy require the study of the pure components to characterize their specific behavior in soil. This is especially important for adsorption behavior of biochar for macro- and micronutrients because in soil there are multiple nutrient sinks that compete with plant roots for vital elements. Therefore this contribution presents results from a field amendment study with pure biochar that had the objective to characterize the macro- and microelement uptake of crops from different soils in two typical Austrian areas of agricultural production. At two locations in North and South-East Austria, two identical field experiments on different soils (Chernozem and Cambisol) were installed in 2011 with varying biochar additions (0, 30 and 90 t/ha) and two nitrogen levels. The biochar was a product from slow pyrolysis of wood (SC Romchar SRL). During the installation of the experiments, the biochar fraction of <2 mm was mixed with surface soil to a depth of 15 cm in plots of 33 m2 each (n=4). Barley (at the Chernozem soil) and maize (at the Cambisol) were cultivated according to standard agricultural practices. The highest crop yields at both

  1. Soil as one of the Istrian terroir attributes

    NASA Astrophysics Data System (ADS)

    Mileusnić, Marta; Tomašić, Elizabeta; Durn, Goran; Ottner, Franz; Wriessnig, Karin; Gracin, Leo; Husnjak, Stjepan

    2014-05-01

    The first written document of viniculture and wine production in Istria dates from antiquity, indicating a very long tradition. Istrian wines are very well known for its quality. It has been commonly accepted that quality, taste and style of wine depends on terroir, i.e. the local environment (eg. soil, bedrock, climate). Good terroirs are those permitting complete but quite slow maturation of cultivars. Although nowadays a strong debate arises concerning the concept of terroir, mainly referring to the relationship between soil properties and wine quality, our goal was to define different soils in Istrian vineyards, to compare their composition and properties and to explain how they could indirectly influence wine quality. As Istrian Malvasia, an indigenous grapevine variety, is the most widespread cultivar in Istria (1,858.8ha, i.e. about 60% of total vineyard surface), soils on different bedrock in vineyards of these variety were chosen for investigation. The studied vineyards, held by the three most prominent Istrian viticulturists known for high and constant quality of this sort of wine with some difference in taste and style, are as follows: (1) Monte Coronichi characterised by soil developed on Cretaceous limestone and wine of characteristic gentle fruit aroma and nice roundness and saltines; (2) Sveta Lucija characterised by soil developed on Eocene flysch and wine with fruit flavour, good body and extract; and (3) Grimalda characterised by soil developed of Eocene flysch and wine with delicate ripe fruit aroma, very good balance and saltines. The study comprised of field soil characterization and collection of disturbed and undisturbed samples from each soil horizon, as well as comprehensive pedological, mineralogical and geochemical soil analyses. It was determined that terra rossa soil is present on limestone at Monte Coronichi; while two different soils are developed on Eocene flysch, vertic cambisol at Sveta Lucija and eutric brown soil at Grimalda

  2. Projected dynamics of abiotic risks in boreal forest ecosystems (SRES A1B, B1)

    NASA Astrophysics Data System (ADS)

    Panferov, O.; Ahrends, B.; Doering, C.; Sogachev, A.

    2009-04-01

    The ongoing climate change causes an increasing frequency of weather extremes (Leckebusch et al., 2008), which can result in wide area damage events (drought, windthrows/breaks) within boreal forest ecosystem. The damage effects, however, depend not only on the strength of a driving force itself (e.g. wind speed) but also on combinations of effecting agents and forest structure. Thus, the present study investigates the projected future developments of abiotic risks in different boreal forests during the 21st Century under conditions of SRES scenarios A1B and B1. Climate scenario data of coupled ECHAM5-MPIOM were downscaled by the regional climate model (CLM) to the spatial resolution of 0.2° x 0.2°, using daily time- steps. With these input data the small-scale modelling with coupled process based sub-models (Jansen et al., 2008) was carried out e.g. for Solling region, (Germany) calculating the water and energy balance of forest ecosystems with modified BROOK 90 (Ahrends et al., 2009) and wind loading on trees with 3D ABL model SCADIS (Panferov and Sogachev, 2008). Norway spruce and Scots pine of various ages were chosen as typical tree species for boreal forest ecosystems and cambisols, podzolic cambisols and stagnosols as typical soil types. The risks of drought and windthrow/breaks for a certain forest stand result from daily combinations of soil water characteristics, static and gust wind loads and soil texture. Damaged stands show higher vulnerability and thus - positive feedback to climate forcing (Vygodskaya et al., 2008). Therefore differences of microclimatological conditions in the remaining stand after changes in forest structure (Radler et al, 2008) were taken into account. Modell output was aggregated to 30-years periods and compared to "present conditions" of 1981-2010. The results show an increment of drought risks towards 2100 caused by changes in precipitation pattern and increase of mean air temperature, whereas the A1B scenario is

  3. Stability of amorphous hydrous manganese oxide in contrasting soils and implications for its use in chemical stabilization of metals/metalloids in contaminated soil environments

    NASA Astrophysics Data System (ADS)

    Ettler, V.; Knytl, V.; Komarek, M.; Della Puppa, L.; Mihaljevic, M.; Sebek, O.

    2012-04-01

    Amorphous manganese oxides are known to be efficient sorbents in soils and thus useful in remediation technologies. A novel amorphous hydrous manganese oxide (HMO) was prepared by a modified procedure generally used for birnessite synthesis. Its long-term stability in view of possible applications for chemical stabilization of metals/metalloids in polluted soils was evaluated. HMO was sealed in experimental bags prepared from polyamide fabric (pore size 1 um) and placed in the pots containing 200 g of soil. Three contrasting soils were used (two cambisols with pH values of 4.2 and 5.4, respectively, and a chernozem with a pH of 7.3). Each pot was equipped with a rhizon pore water sampler and the water content was maintained at 80% WHC throughout the experiment. HMO and pore waters were sampled after 1, 7, 15, 30, 45, 60, 75 and 90 days of incubation. Up to 113 mg Mn/L was released into pore water at the beginning of the experiment in more acidic soils indicating a slight dissolution of HMO surfaces. Manganese release into the pore water stabilized after 15 days in agreement with mass loss measurements. Mass loss decreased again after 60 days of the incubation for the neutral soil due to the formation of secondary rhodochrosite (MnCO3) detected on the HMO surfaces by X-ray diffraction analysis (XRD) and transmission electron microscopy (TEM). The efficiency of HMO for trace metal retention in soils (e.g., Zn) slightly decreased after 60 days, probably due to the mineralogical transformation of the sorbent leading to decrease of binding surfaces. Nevertheless, only approximately 10% of HMO dissolved after 90 days of experiment showing that this sorbent can be relatively stable in the studied soils. Its binding capacity for metals/metalloids should be further tested in soils with elevated contaminant concentrations.

  4. Fluorescence fingerprints and Cu2+-complexing ability of individual molecular size fractions in soil- and waste-borne DOM.

    PubMed

    Knoth de Zarruk, K; Scholer, G; Dudal, Y

    2007-09-01

    Land spreading of organic materials introduces large amounts of dissolved organic matter (DOM) into the soil. DOM has the ability to form stable complexes with heavy metals and can facilitate their transport towards the groundwater. The effects on soil processes are difficult to assess, because different DOM components might react differently towards metal ions. The objective of this study was to investigate the fluorescence signature and the Cu2+-binding capacity of individual molecular size fractions of DOM from various sources. DOM extracted from leaf compost, chicken manure, sugar cane vinasse and a fulvic hypercalcaric cambisol was fractionated by the means of dialysis into four molecular size classes: MW<500, 50012000-14000 Da. Vinasse and leaf compost contained around 80% and 70%, respectively, of the total organic carbon in the fractions with low molecular weight (MW<3500 Da); in chicken manure and soil these fractions accounted for 40% and 50% only. Fluorescence was highest in the fraction MW>12000 Da for leaf compost, chicken manure and soil. The opposite result was obtained for vinasse, where the fractions with low molecular weight showed highest fluorescence intensities, distinguishing it from all other samples. Vinasse showed the greatest ability to bind Cu2+ with a resulting complex concentration of 6.31mgl(-1) while in contact with an excess of Cu2+. Leaf compost, soil and chicken manure followed with 2.69, 1.12, and 0.85mgl(-1), respectively. Within vinasse, the fraction MW<500 Da was able to form the most DOM-Cu complexes, indicating the importance of low molecular weight fractions in metal binding. PMID:17498777

  5. Cosmic Ray Neutron Probe Soil Water Measurements over Complex Terrain in Austria

    NASA Astrophysics Data System (ADS)

    Vreugdenhil, Mariette; Weltin, Georg; Kheng Heng, Lee; Wahbi, Ammar; Oismueller, Markus; Dercon, Gerd

    2014-05-01

    The importance of surface soil water (rooting zone) has become evident with climate change affecting rainfall patterns and crop production. The use of Cosmic Ray Neutron Probe (CRNP) for measuring surface soil water has become increasingly popular. The advantage of CRNP is that it is a non-invasive technique for measuring soil water content at an area-wide scale, in contrast to more conventional, techniques which measure mainly at field scale (point level). The CRNP integrates over a circular area of ca. 600 meters in diameter, to a depth of 70 cm, giving an average value for soil water content. Cosmic radiation interacting with the Earth's atmosphere continuously generates neutrons. At Earth's surface, these neutrons interact with surface water, and are slowed down. At sub-micrometer geometrics, these neutrons affect semiconductor devices, so they can be counted, slow and fast ones separately. From the difference in numbers between fast and slow neutrons, soil water content is calculated. As first in Austria, a CRNP (CRS 1000/B model) consisting of two neutron counters (one tuned for slow, the other one for fast neutrons), data logger and an Iridium modem, has been installed at Petzenkirchen research station of the Doctoral Programme for Water Resource Systems (TU Vienna) at 48.14 latitude and 15.17 longitude, 100 km west of Vienna, in late autumn 2013. The research station is located in an undulating agricultural landscape, characterized by heavy Cambisols and Planosols, and winter wheat and barley as main crops in winter, and maize and sunflower in summer. In addition, an in-situ soil moisture network consisting of 32 stations of Time Domain Transmissivity (TDT) sensors measuring soil water at 4 depths (0.05, 0.10,0.20 and 0.50 m) over an area of 64 ha has been established. This TDT network is currently being used to validate the use of the innovative CRNP technique. First results will be shown at the EGU 2014.

  6. Determination of Preferential Flow Parameters by Means of Inverse Simulation of Tension Disc Experiment

    NASA Astrophysics Data System (ADS)

    Zumr, D.; Snehota, M.; Nemcova, R.; Cislerova, M.

    2008-12-01

    The field tension and ponded infiltration experiments were conducted to estimate the soil hydraulic properties of the soils with preferential pathways (Distric Cambisol, Sumava). Zones of preferential flow were determined through analyses of photographs taken during laboratory dye tracer infiltration experiments performed on undisturbed soil samples. Connectivity, volumetric ratio and spatial development of preferential pathways were evaluated as the necessary information for numerical simulations of flow using dual-permeability approach. The field infiltration experiment was carried out in a shallow pit for a period of one day. The upper boundary condition was controlled by the tension disk infiltrometer, the propagation of a water front was monitored by two tensiometers installed in two depths below the infiltration disk. 2D axisymetric numerical simulations were conducted to evaluate the results of the experiment. Two different approaches were used: 1. Single-domain approach based on Richards' equation. 2. Dual-permeability approach based on two interacting water flow domains (matrix and preferential domains), each governed by one Richards' equation. In the first simulation, the reference parameters derived from retention curves obtained by standard pressure extractor method were taken as properties of the soil matrix. The input hydraulic parameters were subsequently inversely optimized. In the second approach, the saturated hydraulic conductivities of the preferential flow domain were optimized to fit rapid response of the tensiometers after the start of ponded infiltration. Objective function consisted of infiltration fluxes and suction pressure head data. The parameter estimator PEST coupled with the simulation code S2D_DUAL (Vogel et al.,2000) were used. Concerning the existence of preferential flow on investigated soil, the dual-permeability model gives a better picture of the flow regime. The research has been carried out within the projects VZ03 CEZ MSM

  7. Inverse Simulation of Field Infiltration Experiment Counting Preferential Flow

    NASA Astrophysics Data System (ADS)

    Zumr, David; Snehota, Michal; Nemcova, Renata; Dohnal, Michal; Cislerova, Milena

    2010-05-01

    The field tension and ponded infiltration experiments were conducted to monitor and describe irregularities of moisture propagation and to estimate the soil hydraulic properties (Distric Cambisol, Korkusova Hut, Sumava). On these soils the preferential pathways have been observed in several scales with the use of dye tracers, MRI and CT imaging. Preferential behavior was detected also during laboratory infiltration experiments. The flow irregularities are credited to variable air entrapment at the beginning of infiltrations. The field infiltration experiment was carried out in a shallow pit for a period of one day. The upper boundary condition was controlled by the tension disk infiltrometer, the propagation of a water front was monitored by two tensiometers installed in two depths below the infiltration disk. The propagation of saline solution front during ponded infiltration was visualized with high resolution electrical resistivity tomography (ERT). Infiltration experiments were monitored with TDR probes, tensiometers and ERT. Zones of preferential flow were determined through analyses of photographs taken during laboratory dye tracer infiltration experiments performed on undisturbed soil samples. Connectivity, volumetric ratio and spatial development of preferential pathways were evaluated as the necessary information for numerical simulations of flow using dual-permeability approach. 2D axisymetric numerical simulations were conducted to evaluate the results of the experiment. The parameter estimator PEST coupled with the simulation code S2D_DUAL (Vogel et al., 2000) were employed. Two different approaches were used: 1. Single-domain approach based on Richards' equation. 2. Dual-permeability approach based on two interacting water flow domains (matrix and preferential domains), each governed by one Richards' equation. Concerning the existence of preferential flow on investigated soil, the dual-permeability model gives a better picture of the flow regime. The

  8. Si cycling in a forest biogeosystem - the importance of transient state biogenic Si pools

    NASA Astrophysics Data System (ADS)

    Sommer, M.; Jochheim, H.; Höhn, A.; Breuer, J.; Zagorski, Z.; Busse, J.; Barkusky, D.; Meier, K.; Puppe, D.; Wanner, M.; Kaczorek, D.

    2013-07-01

    The relevance of biological Si cycling for dissolved silica (DSi) export from terrestrial biogeosystems is still in debate. Even in systems showing a high content of weatherable minerals, like Cambisols on volcanic tuff, biogenic Si (BSi) might contribute > 50% to DSi (Gerard et al., 2008). However, the number of biogeosystem studies is rather limited for generalized conclusions. To cover one end of controlling factors on DSi, i.e., weatherable minerals content, we studied a forested site with absolute quartz dominance (> 95%). Here we hypothesise minimal effects of chemical weathering of silicates on DSi. During a four year observation period (05/2007-04/2011), we quantified (i) internal and external Si fluxes of a temperate-humid biogeosystem (beech, 120 yr) by BIOME-BGC (version ZALF), (ii) related Si budgets, and (iii) Si pools in soil and beech, chemically as well as by SEM-EDX. For the first time two compartments of biogenic Si in soils were analysed, i.e., phytogenic and zoogenic Si pool (testate amoebae). We quantified an average Si plant uptake of 35 kg Si ha-1 yr-1 - most of which is recycled to the soil by litterfall - and calculated an annual biosilicification from idiosomic testate amoebae of 17 kg Si ha-1. The comparatively high DSi concentrations (6 mg L-1) and DSi exports (12 kg Si ha-1 yr-1) could not be explained by chemical weathering of feldspars or quartz dissolution. Instead, dissolution of a relictic, phytogenic Si pool seems to be the main process for the DSi observed. We identified canopy closure accompanied by a disappearance of grasses as well as the selective extraction of pine trees 30 yr ago as the most probable control for the phenomena observed. From our results we concluded the biogeosystem to be in a transient state in terms of Si cycling.

  9. Si cycling in a forest biogeosystem - the importance of anthropogenic perturbation and induced transient state of biogenic Si pools

    NASA Astrophysics Data System (ADS)

    Sommer, M.; Jochheim, H.; Höhn, A.; Breuer, J.; Zagorski, Z.; Busse, J.; Barkusky, D.; Puppe, D.; Wanner, M.; Kaczorek, D.

    2012-12-01

    The relevance of biological Si cycling for dissolved silica (DSi) export from terrestrial biogeosystems is still in debate. Even in systems showing a high content of weatherable minerals, like Cambisols on volcanic tuff, biogenic Si (BSi) might contribute > 50% to total DSi (Gerard et~al., 2008). However, the actual number of biogeosystem studies is rather limited for generalised conclusions. To cover one end of controlling factors on DSi - weatherable minerals content - we studied a~forested site with absolute quartz dominance (> 95%). Hence, we hypothesise minimal effects of chemical weathering of silicates on DSi. During a~four year observation period (May 2007-April 2011) we quantified (i) internal and external Si fluxes of a temperate-humid biogeosystem (beech, 120 yr) by BIOME-BGC (vers. ZALF), (ii) related Si budgets, and, (iii) Si pools in soil and beech, chemically as well as by SEM-EDX. For the first time both compartments of biogenic Si in soils were analysed, i.e. phytogenic and zoogenic Si pool (testate amoebae). We quantified an average Si plant uptake of 35 kg Si ha-1 yr-1 - most of which is recycled to the soil by litterfall - and calculated an annual biosilicification from idiosomic testate amoebae of 17 kg Si ha-1. High DSi concentrations (6 mg l-1) and DSi exports (12 kg Si ha-1 yr-1) could not be explained by chemical weathering of feldspars or quartz dissolution. Instead, dissolution of a relictic phytolith Si pool seems to be the main process for the DSi observed. We identified forest management, i.e. selective extraction of pine trees 20 yr ago followed by a disappearance of grasses, as the most probable control for the phenomena observed and hypothesised the biogeosystem to be in a transient state in terms of Si cycling.

  10. The Weichselian (Würmian) Pleniglacial chronology of the Nussloch loess section/Germany revisited. Implications for the matching of pedosedimentary units with Greenland stadial and interstadial periods.

    NASA Astrophysics Data System (ADS)

    Kadereit, A.; Kind, C.-J.; Wagner, G. A.

    2012-04-01

    The loess section of Nussloch in SW-Germany is a key profile for the reconstruction of the terrestrial palaeoenvironment of central Europe for the time of the Weichselian (Würmian) Pleniglacial (e.g. Antoine et al., 2009). In this period, the earliest modern humans invaded SW-Germany as documented in unique cultural remains from karst caves of the Swabian Jura (e.g. Conard et al., 2009). The Nussloch profile includes a Middle Pleniglacial Cambisol remain (Lohne Soil), which serves as an important loess marker horizon throughout Europe. Greenland interstadial (GIS) 8 was hitherto regarded as the likely period of soil formation for the Lohne Soil and a suite of partly soliflucted Cryosols in the hanging wall is interpreted to represent warm climate excursions of the Upper Pleniglacial period, starting with GIS8 or GIS7 (e.g. Antoine et al., 2001, 2009; Rousseau et al., 2011). However, revaluation of available chronometric data from Nussloch suggests (GIS7 to) GIS5 as the likely period of soil formation for the Lohne Soil. GIS8 is documented by deposits from thermokarst dynamics, stratigraphically several units below the marker soil. Consequences of a revised chronology for correlations of Pleniglacial Cryosols below and above the Lohne Soil with Greenland interstadials are discussed. The implications are important for European loess research as the Nussloch section serves as a reference base throughout Europe. The revised chronology suggests also that the Lohne Soil postdates the immigration of the earliest modern humans in SW-Germany and central Europe. This finding is in contrast to the earlier age-model for the Nussloch site.

  11. Spatial variability of the dehydrogenase activity in forest soils

    NASA Astrophysics Data System (ADS)

    Błońska, Ewa; Lasota, Jarosław

    2014-05-01

    The aim of this study was to assess the spatial variability of the dehydrogenase activity (DH) in forest soils using geostatistics. We have studied variability soil dehydrogenase and their relationship with variability of some physic-chemical properties. Two study areas (A and B) were set up in southern Poland in the Zlotoryja Forest District. Study areas were covered by different types of vegetation (A- broadleaf forest with beech, ash and sycamore), B- coniferous forest with Norway spruce). The soils were classified as Dystric Cambisols (WRB 2006). The samples for laboratory testing were collected from 49 places on each areas. 15 cm of surface horizon of soil were taken (with previously removed litter). Dehydrogenase activity was marked with Lenhard's method according to the Casida procedure. Soil pH, nitrogen (N) and soil organic carbon (C) content (by LECO CNS 2000 carbon analyzer) was marked. C/N ratio was calculated. Particle size composition was determined using laser diffraction. Statistical analysis were performed using STATISTICA 10 software. Geostatistical analysis and mapping were done by application of GS 9+ (Gamma Design) and Surfer 11 (Golden Software). The activity of DH ranged between 5,02 and 71,20 mg TPP• kg-1 •24 h-1 on the A area and between 0,94 and 16,47 mg TPP• kg-1 •24 h-1. Differences in spatial variability of the analised features were noted. The variability of dehydrogenase activity on the A study area was described by an exponential model, whereas on the B study area the spatial correlation has not been noted. The relationship of dehydrogenase activity with the remaining parameters of soil was noted only in the case of A study area. The variability of organic carbon content on the A and B study areas were described by an exponential model. The variability of nitrogen content on both areas were described by an spherical model.

  12. Black locust--successful invader of a wide range of soil conditions.

    PubMed

    Vítková, Michaela; Tonika, Jaroslav; Müllerová, Jana

    2015-02-01

    Black locust (Robinia pseudoacacia, BL), a species native to North America, has successfully invaded many types of habitats over the world. This study provides an overall assessment of BL soil conditions to determine the range of physical-chemical soil properties it can tolerate. 511 BL stands (for the soil types) and 33 permanent plots (for the soil chemistry) were studied in the Czech Republic. Relationships among different environmental variables (physical-chemical soil properties, vegetation characteristics and habitat conditions) were investigated and variables with the highest effect on species composition were detected. The results were compared with data in the literature for other parts of the secondary and native distributions of this species. This assessment showed that BL is able to tolerate extremely diverse soil physical-chemical conditions, from extremely acid to strongly alkaline, and from medium to highly base saturated soils with a gradient of different subsurface stoniness. Soil nitrate, N mineralization and nitrification rates also varied considerably and the concentrations of exchangeable phosphorus and ammonium were consistently low. N mineralization rate, incubated inorganic nitrogen and nitrates were positively correlated with base saturation and cation exchange capacity. The most common soil types were young soils (Cambisols, Leptosols, Arenosols, and coarsely textured Fluvisols). BL seems to be limited by water supply and soil aeration and prefers well aerated and drained soils, and tolerates desiccation but avoids compact soils and areas where the soils are frequently waterlogged. On steep slopes, BL was less vigorous, stunted and less competitive. By contrast, the tallest BL trees were found on sandy soils in a flat landscape. Number and share of nitrophytes in the herb layer were positively related to basic bedrock, soil reaction and N-NO3/N ratio. Soil reaction was determined as the most important environmental characteristic

  13. Thermal treatment and leaching of biochar alleviates plant growth inhibition from mobile organic compounds

    PubMed Central

    Sackett, Tara E.; Thomas, Sean C.

    2016-01-01

    Recent meta-analyses of plant responses to biochar boast positive average effects of between 10 and 40%. Plant responses, however, vary greatly across systems, and null or negative biochar effects are increasingly reported. The mechanisms responsible for such responses remain unclear. In a glasshouse experiment we tested the effects of three forestry residue wood biochars, applied at five dosages (0, 5, 10, 20, and 50 t/ha) to a temperate forest drystic cambisol as direct surface applications and as complete soil mixes on the herbaceous pioneers Lolium multiflorum and Trifolium repens. Null and negative effects of biochar on growth were found in most cases. One potential cause for null and negative plant responses to biochar is plant exposure to mobile compounds produced during pyrolysis that leach or evolve following additions of biochars to soil. In a second glasshouse experiment we examined the effects of simple leaching and heating techniques to ameliorate potentially phytotoxic effects of volatile and leachable compounds released from biochar. We used Solid Phase Microextraction (SPME)–gas chromatography–mass spectrometry (GC-MS) to qualitatively describe organic compounds in both biochar (through headspace extraction), and in the water leachates (through direct injection). Convection heating and water leaching of biochar prior to application alleviated growth inhibition. Additionally, growth was inhibited when filtrate from water-leached biochar was applied following germination. SPME-GC-MS detected primarily short-chained carboxylic acids and phenolics in both the leachates and solid chars, with relatively high concentrations of several known phytotoxic compounds including acetic acid, butyric acid, 2,4-di-tert-butylphenol and benzoic acid. We speculate that variable plant responses to phytotoxic organic compounds leached from biochars may largely explain negative plant growth responses and also account for strongly species-specific patterns of plant

  14. Contents and composition of organic matter in subsurface soils affected by land use and soil mineralogy

    NASA Astrophysics Data System (ADS)

    Ellerbrock, Ruth H.; Kaiser, Michael

    2010-05-01

    Land use and mineralogy affect the ability of surface as well as subsurface soils to sequester organic carbon and their contribution to mitigate the greenhouse effect. This study aimed to investigate the long-term impact of land use (i.e., arable and forest) and soil mineralogy on contents and composition of soil organic matter (SOM) from subsurface soils. Seven soils different in mineralogy (Albic and Haplic Luvisol, Colluvic and Haplic Regosol, Haplic and Vertic Cambisol, Haplic Stagnosol) were selected within Germany. Soil samples were taken from forest and adjacent arable sites. First, particulate and water soluble organic matter were separated from the subsurface soil samples. From the remaining solid residues the OM(PY) fractions were separated, analyzed for its OC content (OCPY) and characterized by FTIR spectroscopy. For the arable subsurface soils multiple regression analyses indicate significant positive relationships between the soil organic carbon contents and the contents of i) exchangeable Ca and oxalate soluble Fe, and Alox contents. Further for the neutral arable subsurface soils the contents OCPY weighted by its C=O contents were found to be related to the contents of Ca indicating interactions between OM(PY) and Ca cations. For the forest subsurface soils (pH <5) the OCPY contents were positively related with the contents of Na-pyrophosphate soluble Fe and Al. For the acidic forest subsurface soils such findings indicate interactions between OM(PY) and Fe3+ and Al3+ cations. The effects of land use and soil mineralogy on contents and composition of SOM and OM(PY) will be discussed.

  15. Effects of cattle-slurry treatment by acidification and separation on nitrogen dynamics and global warming potential after surface application to an acidic soil.

    PubMed

    Fangueiro, David; Pereira, José; Bichana, André; Surgy, Sónia; Cabral, Fernanda; Coutinho, João

    2015-10-01

    Cattle-slurry (liquid manure) application to soil is a common practice to provide nutrients and organic matter for crop growth but it also strongly impacts the environment. The objective of the present study was to assess the efficiency of cattle-slurry treatment by solid-liquid separation and/or acidification on nitrogen dynamics and global warming potential (GWP) following application to an acidic soil. An aerobic laboratory incubation was performed over 92 days with a Dystric Cambisol amended with raw cattle-slurry or separated liquid fraction (LF) treated or not by acidification to pH 5.5 by addition of sulphuric acid. Soil mineral N contents and NH3, N2O, CH4 and CO2 emissions were measured. Results obtained suggest that the acidification of raw cattle-slurry reduced significantly NH3 emissions (-88%) but also the GWP (-28%) while increased the N availability relative to raw cattle-slurry (15% of organic N applied mineralised against negative mineralisation in raw slurry). However, similar NH3 emissions and GWP were observed in acidified LF and non-acidified LF treatments. On the other hand, soil application of acidified cattle-slurry rather than non-acidified LF should be preferred attending the lower costs associated to acidification compared to solid-liquid separation. It can then be concluded that cattle-slurry acidification is a solution to minimise NH3 emissions from amended soil and an efficient strategy to decrease the GWP associated with slurry application to soil. Furthermore, the more intense N mineralisation observed with acidified slurry should lead to a higher amount of plant available N and consequently to higher crop yields. PMID:26217884

  16. Temporal changes of topsoil hydraulic conductivity studied by multiple-point tension disk infiltrometer

    NASA Astrophysics Data System (ADS)

    Klipa, Vladimir; Zumr, David; Snehota, Michal; Dohnal, Michal

    2015-04-01

    Hydraulic conductivity of cultivated soils is strongly affected by agrotechnical procedures, soil compaction, plant growth etc. This contribution is focused on series of measurement of topsoil unsaturated hydraulic conductivity using automated multipoint tension infiltrometer developed at CTU in Prague. The apparatus consists of two triplets of minidisk infiltrometers that are supported by a light aluminum frame. Therefore it allows simultaneous measurement of six tension infiltrations at two different pressure heads. Experiments were conducted at the experimental agricultural catchment Nučice (Central Bohemia, Czech Republic) as a part of the broader research of rainfall-runoff and soil erosion processes. The soil in the catchment is classified as Cambisol with texture that is ranging from loam to clay loam and is conservatively tilled. Series of ten infiltration campaigns (56 individual infiltration experiments) were carried out on a single experimental plot during period of two years. Dataset involves measurement under various agricultural activities and crop phenophases. The hydraulic conductivities were determined using extended semiempirical estimation procedure of Zhang. Additionally, large undisturbed soil samples were analyzed with use of X-ray computed tomography to assess the soil structure morphology in detail. Results show that unsaturated hydraulic conductivity was the lowest in early spring and did increase at beginning of summer. Unsaturated soil hydraulic conductivity was higher when the soil bulk density was high. During the summer and autumn the unsaturated hydraulic conductivity remained relatively unchanged. The impact of agricultural procedures was not apparent in the dataset.. The study has been supported by the Czech Science Foundation Project No. 13-20388P and by CTU in Prague funding via Student's Grant Competition SGS No. SGS14/131/OHK1/2T/11. The MultiDisk infiltrometer was developed within the framework of the project supported by the

  17. A long-term field experiment of soil transplantation demonstrating the role of contemporary geographic separation in shaping soil microbial community structure

    PubMed Central

    Sun, Bo; Wang, Feng; Jiang, Yuji; Li, Yun; Dong, Zhixin; Li, Zhongpei; Zhang, Xue-Xian

    2014-01-01

    The spatial patterns of microbial communities are largely determined by the combined effects of historical contingencies and contemporary environmental disturbances, but their relative importance remains poorly understood. Empirical biogeographic data currently available are mostly based on the traditional method of observational survey, which typically involves comparing indigenous microbial communities across spatial scales. Here, we report a long-term soil transplantation experiment, whereby the same two soils (red Acrisol and purple Cambisol from Yingtan) were placed into two geographic locations of ∼1000 km apart (i.e., Yingtan in the mid-subtropical region and Fengqiu in warm-temperate region; both located in China). Twenty years after the transplantation, the resulting soil microbial communities were subject to high-throughput 454 pyrosequencing analysis of 16S and 18S rRNA genes. Additionally, bacteria and archaea involved in nitrogen cycling were estimated using clone library analysis of four genes: archaeal amoA, bacterial amoA,nirK, and nifH. Data of subsequent phylogenetic analysis show that bacteria, fungi, and other microbial eukaryotes, as well as the nitrogen cycling genes, are grouped primarily by the factor of geographic location rather than soil type. Moreover, a shift of microbial communities toward those in local soil (i.e., Chao soil in Fengqiu) has been observed. The results thus suggest that the historical effects persistent in the soil microbial communities can be largely erased by contemporary disturbance within a short period of 20 years, implicating weak effects of historical contingencies on the structure and composition of microbial communities in the soil. PMID:24772284

  18. Assessment of land use in protected areas of the state of Sao Paulo, Brazil

    NASA Astrophysics Data System (ADS)

    Iori, P.; da Silva, R. B.; Dias Junior, M. S.; Paz González, A.

    2012-04-01

    It is of universal knowledge that the soil, a basic natural resource, is renewable only if conserved or used correctly(Primavesi, 2002). It is salient for Araújo et al. (2007) that the establishment of index of soil quality is an important tool in the functions of control, supervision and monitoring of areas for environmental protection. The objective of this study was to compare the quality of the soil by means of a comparative diagram in different soil uses in permanent preservation areas (APP). The study was conducted in areas near the Ribeira de Iguape river in the city of Registro - São Paulo - Brazil, belonging to the Atlantic Forest domain, a Haplic Cambisol. The following uses of the soil had been evaluated: a) banana culture (CBAN) without agricultural traffic of machines; b) degraded pasture (PDEG) with extensive system predominantly Brachiaria decumbens L. c) use silvopastoral (MPIs), consisted in a kills with a traffic free for the animals, and d) native vegetation (MNAT), proposed in this study as a reference area.The following physical indicators were analyzed: bulk density (BD), total soil porosity (TP), macroporosity (Ma), microporosity (Mi), water dispersible clay (ADA), flocculation index (FI), preconsolidation pressure (PP), soil shear strength (SS), soil resistance to penetration (RP). To construct the comparative diagram the values for each attribute of the soil in each land use were related to the values of the native forest. It was feasible to use the comparative model in the qualitative evaluation of soil use, allowing separate environments under different uses. According to the comparative diagram of banana culture is the use that most negatively impacts the physical and mechanical soil due to the smaller size of the lower polygon.

  19. Characterization of sorption properties of selected soils from Lublin region by using water vapour adsorption method

    NASA Astrophysics Data System (ADS)

    Skic, Kamil; Boguta, Patrycja; Sokołowska, Zofia

    2016-04-01

    *The studies were carried out within the framework of a research project. The project was financed from funds of National Science Center on the base of decision number DEC-2013/11/D/NZ9/02545 Among many methods proposed to study sorption properties of soils an analysis of adsorption/ desorption isotherm is probably the easiest and most convenient one. It characterizes both quantity and quality of mineral and organic components and also their physical and physicochemical properties. The main aim of this study is comparison of sorption properties of selected Polish soils by using water vapour adsorption method. Samples were taken from the depth of 0-20 cm, from the Lublin region, eastern Poland. Soils were selected on the basis of their different physicochemical properties and were classified as: Haplic Fluvisol, Haplic Chernozem, Mollic Gleysol, Rendzic Phaeozem, Stagnic Luvisol, Haplic Cambisol (WG WRB 2006). Data taken from experimental adsorption isotherms were used to determine parameters of monolayer capacity, specific surface area and the total amount of vapour adsorbed at relative pressure of 0.974. Obtained adsorption and desorption isotherms reviled that adsorbate molecules interacted with the soil particles in different extent. Similar monolayer capacity was observed for Haplic Fluvisol, Haplic Chernozem and Stagnic Luvisol, while for Mollic Gleysol was more than 4 times higher. Mollic Gleysol was also characterized by highest values of specific surface area as well as quantity of adsorbed vapour at relative pressure of 0.974. Higher sorption was caused by presence of soil colloids which contains functional groups of a polar nature (mainly hydroxyls, phenolic and carboxyls). These groups similarly to silicates, oxides, hydratable cations as well as electric charge form adsorption centres for water vapour molecules.

  20. Inverse modelling of multiple infiltration-outflow experiments

    NASA Astrophysics Data System (ADS)

    Sobotková, M.; Snehota, M.; Dohnal, M.; Cislerova, M.

    2009-04-01

    Changes of (quasi)steady state water flow rates were observed in laboratory infiltration experiments done on columns of compacted sand and on two undisturbed soil columns of sandy loam and loamy sand cambisol soil. Infiltration-outflow experiments consisted of series of ponded infiltration runs with seepage face boundary condition at the lower end of columns. The initial water contents were different for each run. The results of the experiment done on an undisturbed soil column showed that the flux rates and water contents measured during quasi-steady state differ between infiltration runs. This finding contradicts the standard theory. The fluctuations of the water content during the steady state flow can be ascribed to the variations in volume of the entrapped air. The same behaviour was not observed in the sample of homogeneous sand. Computer tomography was used to characterize the structure of the undisturbed soil sample with focus on potential preferential flow pathways. In order to asses the changes between runs quantitatively, hydraulic characteristics were estimated for each infiltration run separately by inverse modelling. Experimental outflow data and tensiometric pressure head data were used as an input for inverse modelling. Numerical code based on dual permeability approach was coupled with parameter estimator. Result of the inverse modelling for each column is specific set of hydraulic properties for each infiltration run of particular soil column. Since we hypothesise that the steady state flow is affected by soil water content at the beginning of the infiltration run, we will study the relationships between initial moistures and hydraulic parameters values. Furthermore we will test if the above phenomena can be ascribed to hysteresis of hydraulic functions.

  1. GEMAS results from the Pannonian Basin - geochemical signatures in a transnational geological structure

    NASA Astrophysics Data System (ADS)

    Haslinger, Edith; Jordan, Gyozo; Slaninka, Igor; Sorsa, Ajka; Gulan, Aleksandra; Gosar, Mateja; Hratovic, Hazim; Klos, Volodymyr

    2014-05-01

    The Pannonian Basin, also referred to as Carpathian Basin, has its geological origins in the Pannonian Sea which was part of the Parathetys Sea, from which it was separated around 10 Ma ago. It spreads over large part of the southeastern part of Central Europe. The centre of the Pannonian Basin is located in Hungary and extends to the adjoining countries Austria, Slovakia, Romania, Ukraine, Croatia, Serbia, Slovenia and Bosnia-Herzegovina. The basin is surrounded by the Carpathian Mountains, the Alps, the Dinarides and the Balkan mountains. The Pannonian Basin is filled by Molasse sediments, which were deposited during the Alpine orogenesis and originating from the rising Alpine and Carpathian Mountain chains. The orogenesis continued during the sedimentation into the Molasse basin. The tectonic movements resulted in several cycles of trans- and regressions of the Parathetys, the sedimentation of marine and freshwater sediments as well as a multitude of fractures and cleavages during the orogensis and the subsidence of different parts of the basin. Even if the Pannonian Basin was formed during a complex orogenesis, it can be regarded as a geo- and hydrodynamic unit. In accordance with the geological history, the soils in the Pannonian Basin developed on loose sediments - including significant loess deposits - and are dominated by soil types which also reflect the continental and steppe climate in this area - Planosols, Luvisols, Cambisols, Calcisols, Chernozems and Phaeozems. The basin is extensively used for agricultural purposes. The geochemical patterns Pannonian Basin are considerably different compared to its surroundings due to its geological development. The spatial distribution of some elements (REE (La, Ce), Y, Th, V, Cd, Pb) are clearly different inside and outside the basin area. For this transnational geological and geographical area, the GEMAS results are compiled and multivariate statistics are applied to find common geochemical signatures in relation

  2. As, Cd, Cr, Ni and Pb pressurized liquid extraction with acetic acid from marine sediment and soil samples

    NASA Astrophysics Data System (ADS)

    Moreda-Piñeiro, Jorge; Alonso-Rodríguez, Elia; López-Mahía, Purificación; Muniategui-Lorenzo, Soledad; Prada-Rodríguez, Darío; Moreda-Piñeiro, Antonio; Bermejo-Barrera, Adela; Bermejo-Barrera, Pilar

    2006-12-01

    Rapid leaching procedures by Pressurized Liquid Extraction (PLE) have been developed for As, Cd, Cr, Ni and Pb leaching from environmental matrices (marine sediment and soil samples). The Pressurized Liquid Extraction is completed after 16 min. The released elements by acetic acid Pressurized Liquid Extraction have been evaluated by inductively coupled plasma-optical emission spectrometry. The optimum multi-element leaching conditions when using 5.0 ml stainless steel extraction cells, were: acetic acid concentration 8.0 M, extraction temperature 100 °C, pressure 1500 psi, static time 5 min, flush solvent 60%, two extraction steps and 0.50 g of diatomaceous earth as dispersing agent (diatomaceous earth mass/sample mass ratio of 2). Results have showed that high acetic acid concentrations and high extraction temperatures increase the metal leaching efficiency. Limits of detection (between 0.12 and 0.5 μg g - 1 ) and repeatability of the over-all procedure (around 6.0%) were assessed. Finally, accuracy was studied by analyzing PACS-2 (marine sediment), GBW-07409 (soil), IRANT-12-1-07 (cambisol soil) and IRANT-12-1-08 (luvisol soil) certified reference materials (CRMs). These certified reference materials offer certified concentrations ranges between 2.9 and 26.2 μg g - 1 for As, from 0.068 to 2.85 μg g - 1 for Cd, between 26.4 and 90.7 μg g - 1 for Cr, from 9.3 to 40.0 μg g - 1 for Ni and between 16.3 and 183.0 μg g - 1 for Pb. Recoveries after analysis were between 95.7 and 105.1% for As, 96.2% for Cd, 95.2 and 100.6% for Cr, 95.7 and 103% for Ni and 94.2 and 105.5% for Pb.

  3. Characterization of soil organic matter composition at intact preferential flow path surfaces

    NASA Astrophysics Data System (ADS)

    Leue, M.; Gerke, H. H.; Ellerbrock, R. H.

    2012-04-01

    In structured soils, the interaction of percolating water and reactive solutes with the soil matrix is mostly restricted to surfaces of preferential flow paths. Surfaces of flow paths that are formed by cracks, decayed root channels or worm burrows are often covered by clay-organic coatings (i.e., cutanes), in which the outermost layer is mainly organic matter (OM). The composition of OM finally controls wettability, sorption, and transfer properties. However, the in-situ local distribution of OM properties along such surfaces is largely unknown to date because experimental techniques to study the relatively thin and vulnerable coatings at intact structure surfaces were not available. The objective of this study was to analyze the local mm-scale distribution and composition of SOM at preferential flow paths. The Fourier transformed infrared spectroscopy in diffuse reflectance mode (DRIFT) was used to determine spectral information of the intact structural surfaces (cracks and biopores). With the DRIFT-mapping technique, potential flow path types, such as earthworm burrows, root channels, and cracks of structured subsoil horizons were analyzed in 1 mm steps along transects of 15 up to 65 mm length. The distribution of OM composition was characterized by evaluating the ratios of the absorption band intensities of the alkyl- (C-H-) and carbonyl (C=O-) functional groups (CH/CO), which represent a measure of the potential wettability of the OM of the surface. Samples of different soil types (Luvisol, Regosol, Stagnosol, Cambisol), of different geological provenance (till, loess, mudstone, limestone), and of different land use (arable, forest) were analyzed. The CH/CO-ratio was generally higher for earthworm burrows and root channels as compared to crack surfaces and the soil matrix. Differences between flow path types could be observed with respect to soil type, parent material, and land use. The local distribution of the OM properties may affect sorption and mass

  4. Does biochar with organic amendments affect denitrification in an agricultural soil?

    NASA Astrophysics Data System (ADS)

    Maier, Regine; Soja, Gerhard; Friesl Hanl, Wolfgang; Dunst, Gerald; Kitzler, Barbara

    2016-04-01

    In this laboratory experiment we investigated the influence of biochar (BC) application on dinitrogen (N2) and nitrous oxide (N2O) emissions from an agricultural soil in Austria. We produced BC at 550°C from fiber sludge and husk, partly enriched with ammonium sulfate and mixed with garden green compost at a 50/50 ratio (w/w). The gleyic Cambisol originates from an experimental site in Kaindorf, Austria. For the incubation experiment we established three different treatments in 2014: K (control plots); T1 (1 % BC-compost mixture) and T2 (0.5 % BC-compost mixture enriched with 175 kg N ha-1). We used the helium gas flow soil core technique to quantify N2 and N2O fluxes simultaneously. Therefore, we incubated soil cores at ambient air temperature (20 and 24°C) at 20 and 50% water filled pore space (WFPS). Results show that before BC addition N2 and N2O fluxes were similar at all treatments. Measurements of pure nitrogen-enriched BC show very high gaseous losses in form of N2 and N2O. Raising temperature promotes N2 production at all treatments. Application of N-enriched BC led to significantly higher N2 fluxes compared to K. N2O fluxes increased significantly at fertilized BC plots (T2) compared to K and T1 at both water contents. Raising WFPS supports higher N2 production at all treatments but lowers N2 fluxes at BC plots.

  5. Effect of polyacrylamide as a post-fire erosion mitigation treatment during consecutive rainstorms

    NASA Astrophysics Data System (ADS)

    Inbar, Assaf; Ben-Hur, Meni; Sternberg, Marcelo; Liñares, Marcos

    2014-05-01

    Anionic polyacrylamide (PAM) has been proven to be an effective chemical soil amendment for reducing erosion in arable lands and infrastructure projects, but few attempts have been made to use it as a post-fire mitigation measure. Moreover, the mechanisms by which PAM reduces soil erosion are not fully understood. In this study, we tested the use of 50 kg/ha granular PAM as a post-fire amendment on infiltration rate (IR), runoff and soil loss both in laboratory and field experiments involving multiple rainstorms. In the laboratory experiments, three consecutive storms separated by drying periods were applied by means of a rainfall simulator to two contrasting soils affected by fire (Humic Cambisol and Calcic Regosol). During the 1st rainstorm, PAM decreased IR and increased runoff in both soils due to an increase in viscosity of the runoff and soil solution. At the same time, a reduction in soil loss was observed in both PAM-treated soils compared to the untreated controls. During the first drying period, PAM was irreversibly adsorbed to soil particles, and in the following storms PAM-induced soil loss reduction persisted while the effect of the polymer on IR and runoff was reversed. Differences in the effect of PAM on soil erosion between soils were attributed to changes in the electrolyte concentration of runoff and soil solution. The positive effect of PAM on post-fire soil loss was confirmed in field experiments with erosion plots constructed in the burnt Calcic Regosol. The application of 25 and 50 kg/ha of granular PAM reduced soil erosion by 23 and 57%, respectively, compared to the untreated control. Runoff was reduced only in the 50 kg/ha treatment. It is suggested that the application of PAM could be a good alternative to current post-fire erosion mitigation measures.

  6. Experimental investigation of infiltration in soil with occurrence of preferential flow and air trapping

    NASA Astrophysics Data System (ADS)

    Snehota, Michal; Jelinkova, Vladimira; Sacha, Jan; Cislerova, Milena

    2015-04-01

    Recently, a number of infiltration experiments have not proved the validity of standard Richards' theory of the flow in soils with wide pore size distribution. Water flow in such soils under near-saturated conditions often exhibits preferential flow and temporal instability of the saturated hydraulic conductivity. An intact sample of coarse sandy loam from Cambisol series containing naturally developed vertically connected macropore was investigated during recurrent ponding infiltration (RPI) experiments conducted during period of 30 hours. RPI experiment consisted of two ponded infiltration runs, each followed by free gravitational draining of the sample. Three-dimensional neutron tomography (NT) image of the dry sample was acquired before the infiltration begun. The dynamics of the wetting front advancement was investigated by a sequence of neutron radiography (NR) images. Analysis of NR showed that water front moved preferentially through the macropore at the approximate speed of 2 mm/sec, which was significantly faster pace than the 0.3 mm/sec wetting advancement in the surrounding soil matrix. After the water started to flow out of the sample, changes in the local water content distribution were evaluated quantitatively by subtracting the NT image of the dry sample from subsequent tomography images. As a next stage, the experiment was repeated on a composed sample packed of ceramic and coarse sand. Series of infiltration runs was conducted in the sample with different initial water contents. The neutron tomography data quantitatively showed that both in natural soil sample containing the macropore and in the composed sample air was gradually transported from the region of fine soil matrix to the macropores or to the coarser material. The accumulation of the air bubbles in the large pores affected the hydraulic conductivity of the sample reducing it up to 50% of the initial value. This supports the hypothesis on strong influence of entrapped air amount and

  7. Infiltration in heterogeneous soil monitored by neutron imaging

    NASA Astrophysics Data System (ADS)

    Snehota, Michal; Sobotkova, Martina; Jelinkova, Vladimira; Sacha, Jan; Vontobel, Peter; Cislerova, Milena

    2014-05-01

    The process of infiltration in near-saturated soil and fate of residual air bubbles was studied using neutron imaging. It is the continuation of previous study on flow instability. Ponding infiltration-outflow experiment conducted at NEUTRA beamline of the Spallation Neutron Source Division, Paul Scherrer Institut aimed at i) characterizing the types of structures susceptible to air trapping, ii) monitoring of entrapped air and water redistribution during steady state flow iii) imaging the process of entrapped air dissolution. Experiments were conducted on series of undisturbed samples of soil from the Cambisol series and on an artificially prepared sample. The latter was composed of coarse sand (representing pathways of fast preferential flow), which surrounded blocks of fine ceramic. Cumulative infiltration and outflow fluxes of water were measured gravimetrically by two precision digital scales thus the full water balance data were obtained. Small samples (30 mm in diameter) were used to achieve good spatial resolution of neutron images. Degassed water was used to dissolve bubbles of entrapped air at the end of infiltration experiments. The neutron radiography and tomography data show quantitatively exchange of water and air between domains of fine and coarse materials during quasi-steady state flow in the sample. The redistribution of the entrapped air directly affected the hydraulic conductivity. On neutron tomography images the gradual dissolving of trapped air bubbles was clearly detected. The effect also led to significant increase of hydraulic conductivity. The obtained data show clearly that air as a non-wetting phase should not be overlooked in case of near-saturated infiltration in soil with preferential flow. The research was supported by the Czech Science Foundation Project No. 14-03691S.

  8. Soil-plant water status and wine quality: the case study of Aglianico wine (the ZOViSA project)

    NASA Astrophysics Data System (ADS)

    Bonfante, Antonello; Manna, Piero; Albrizio, Rossella; Basile, Angelo; Agrillo, Antonietta; De Mascellis, Roberto; Caputo, Pellegrina; Delle Cave, Aniello; Gambuti, Angelita; Giorio, Pasquale; Guida, Gianpiero; Minieri, Luciana; Moio, Luigi; Orefice, Nadia; Terribile, Fabio

    2014-05-01

    The terroir analysis, aiming to achieve a better use of environmental features with respect to plant requirement and wine production, needs to be strongly rooted on hydropedology. In fact, the relations between wine quality and soil moisture regime during the cropping season is well established. The ZOViSA Project (Viticultural zoning at farm scale) tests a new physically oriented approach to terroir analysis based on the relations between the soil-plant water status and wine quality. The project is conducted in southern Italy in the farm Quintodecimo of Mirabella Eclano (AV) located in the Campania region, devoted to quality Aglianico red wine production (DOC). The soil spatial distribution of study area (about 3 ha) was recognized by classical soil survey and geophysics scan by EM38DD; then the soil-plant water status was monitored for three years in two experimental plots from two different soils (Cambisol and Calcisol). Daily climate variables (temperature, solar radiation, rainfall, wind), daily soil water variables (through TDR probes and tensiometers), crop development (biometric and physiological parameters), and grape must and wine quality were monitored. The agro-hydrological model SWAP was calibrated and applied in the two experimental plots to estimate soil-plant water status in different crop phenological stages. The effects of crop water status on crop response and wine quality was evaluated in two different pedo-systems, comparing the crop water stress index with both: crop physiological measurements (leaf gas exchange, leaf water potential, chlorophyll content, LAI measurement), grape bunches measurements (berry weight, sugar content, titratable acidity, etc.) and wine quality (aromatic response). Finally a "spatial application" of the model was carried out and different terroirs defined.

  9. Short-term bioavailability of carbon in soil organic matter fractions of different particle sizes and densities in grassland ecosystems.

    PubMed

    Breulmann, Marc; Masyutenko, Nina Petrovna; Kogut, Boris Maratovich; Schroll, Reiner; Dörfler, Ulrike; Buscot, François; Schulz, Elke

    2014-11-01

    The quality, stability and availability of organic carbon (OC) in soil organic matter (SOM) can vary widely between differently managed ecosystems. Several approaches have been developed for isolating SOM fractions to examine their ecological roles, but links between the bioavailability of the OC of size-density fractions and soil microbial communities have not been previously explored. Thus, in the presented laboratory study we investigated the potential bioavailability of OC and the structure of associated microbial communities in different particle-size and density fractions of SOM. For this we used samples from four grassland ecosystems with contrasting management intensity regimes and two soil types: a Haplic Cambisol and a typical Chernozem. A combined size-density fractionation protocol was applied to separate clay-associated SOM fractions (CF1, <1 μm; CF2, 1-2 μm) from light SOM fractions (LF1, <1.8 g cm(-3); LF2, 1.8-2.0 g cm(-3)). These fractions were used as carbon sources in a respiration experiment to determine their potential bioavailability. Measured CO2-release was used as an index of substrate accessibility and linked to the soil microbial community structure, as determined by phospholipid fatty acids (PLFA) analysis. Several key factors controlling decomposition processes, and thus the potential bioavailability of OC, were identified: management intensity and the plant community composition of the grasslands (both of which affect the chemical composition and turnover of OC) and specific properties of individual SOM fractions. The PLFA patterns highlighted differences in the composition of microbial communities associated with the examined grasslands, and SOM fractions, providing the first broad insights into their active microbial communities. From observed interactions between abiotic and biotic factors affecting the decomposition of SOM fractions we demonstrate that increasing management intensity could enhance the potential bioavailability of

  10. Soil cover by natural trees in agroforestry systems

    NASA Astrophysics Data System (ADS)

    Diaz-Ambrona, C. G. H.; Almoguera Millán, C.; Tarquis Alfonso, A.

    2009-04-01

    The dehesa is common agroforestry system in the Iberian Peninsula. These open oak parklands with silvo-pastoral use cover about two million hectares. Traditionally annual pastures have been grazed by cows, sheep and also goats while acorns feed Iberian pig diet. Evergreen oak (Quercus ilex L.) has other uses as fuelwood collection and folder after tree pruning. The hypothesis of this work is that tree density and canopy depend on soil types. We using the spanish GIS called SIGPAC to download the images of dehesa in areas with different soil types. True colour images were restoring to a binary code, previously canopy colour range was selected. Soil cover by tree canopy was calculated and number of trees. Processing result was comparable to real data. With these data we have applied a dynamic simulation model Dehesa to determine evergreen oak acorn and annual pasture production. The model Dehesa is divided into five submodels: Climate, Soil, Evergreen oak, Pasture and Grazing. The first three require the inputs: (i) daily weather data (maximum and minimum temperatures, precipitation and solar radiation); (ii) the soil input parameters for three horizons (thickness, field capacity, permanent wilting point, and bulk density); and (iii) the tree characterization of the dehesa (tree density, canopy diameter and height, and diameter of the trunk). The influence of tree on pasture potential production is inversely proportional to the canopy cover. Acorn production increase with tree canopy cover until stabilizing itself, and will decrease if density becomes too high (more than 80% soil tree cover) at that point there is competition between the trees. Main driving force for dehesa productivity is soil type for pasture, and tree cover for acorn production. Highest pasture productivity was obtained on soil Dystric Planosol (Alfisol), Dystric Cambisol and Chromo-calcic-luvisol, these soils only cover 22.4% of southwest of the Iberian peninssula. Lowest productivity was

  11. National magnetic database for the topsoil samples from Bulgaria

    NASA Astrophysics Data System (ADS)

    Jordanova, Diana; Jordanova, Neli; Petrov, Petar

    2015-04-01

    Establishment of topsoil magnetic database on a national scale provides important source of information, necessary for the purposes of soil classification; soil drainage; as an indirect estimate of the total soil carbon and initial planning in precision agriculture. Five hundred and ten topsoil samples from the upper 20cm of natural unpolluted soils from the territory of Bulgaria have been characterized by detailed magnetic measurements, including mass-specific magnetic susceptibility; frequency dependent magnetic susceptibility, Anhysteretic remanence, Isothermal remanence and their ratios; hysteresis parameters and ratios; as well as soil reaction (pH). Histograms of the measured parameters per soil type and for the whole database reveal specific peculiarities and dependence from different factors. According to the results from the factor analysis, 77% from the total variance can be explained by four factors. The main factor is dominated by the contribution from concentration-dependent magnetic parameters. The second factor reflects the role of fine-grained pedogenic magnetic fraction; while the third one is determined by the properties of the parent material. The fourth factor is governed by the effects from the internal structural peculiarities of the magnetic particles. The results from cluster analysis reveal the role of soil type and geology for the observed magnetic characteristics. The first two clusters separate soils, developed on volcanogenic/volcanic rocks and loess sediments. The third cluster is dominated by the soil type variable and includes mainly Cambisols, developed on different parent rocks. The fourth cluster separates soils developed on sedimentary rocks. The results emphasize the major role of geology (parent material) for the magnetic signature of topsoil samples on a national scale using sampling density of 1sample/200km2.

  12. Initial Effects of Differently Treated Biogas Residues from Municipal and Industrial Wastes on Spring Barley Yield Formation.

    PubMed

    Prays, Nadia; Kaupenjohann, Martin

    2016-01-01

    Soil application of biogas residues (BGRs) is important for closing nutrient cycles. This study examined the efficiency and impact on yields and yield formation of solid-liquid separated residues from biodegradable municipal and industrial wastes (bio-waste) in comparison to complete BGRs, nitrification inhibitor, agricultural BGRs, mineral fertilizer and unfertilized plots as control. The experiment was set up as a randomized block design on silt loam Cambisol. Biogas residues from four biogas plants were evaluated. Plants per m², ears per plant, grains per ear and thousand grain weight (TGW) were measured at harvest. Fertilization with BGRs resulted in similar biomass yields compared with mineral fertilizer. Mineral fertilizer (71 dt/ha) and plots fertilized with liquid fraction (59-62 dt/ha) indicated a trend to higher yields than solid fraction or complete BGR due to its high ammonia content. Liquid fractions and fraction with nitrification inhibitor induced fewer plants per m² than corresponding solid and complete variants due to a potential phytotoxicity of high NH4-N concentration during germination. However, barley on plots fertilized with liquid fraction compensated the disadvantages at the beginning during the vegetation period and induced higher grain yields than solid fraction. This was attributable to a higher number of ears per plant and grains per ear. In conclusion, BGRs from biodegradable municipal and industrial wastes can be used for soil fertilization and replace considerable amounts of mineral fertilizer. Our study showed that direct application of the liquid fraction of BGR is the most suitable strategy to achieve highest grain yields. Nevertheless potential phytotoxicity of the high NH4-N concentration in the liquid fraction should be considered. PMID:27116355

  13. Initial Effects of Differently Treated Biogas Residues from Municipal and Industrial Wastes on Spring Barley Yield Formation

    PubMed Central

    Prays, Nadia; Kaupenjohann, Martin

    2016-01-01

    Soil application of biogas residues (BGRs) is important for closing nutrient cycles. This study examined the efficiency and impact on yields and yield formation of solid-liquid separated residues from biodegradable municipal and industrial wastes (bio-waste) in comparison to complete BGRs, nitrification inhibitor, agricultural BGRs, mineral fertilizer and unfertilized plots as control. The experiment was set up as a randomized block design on silt loam Cambisol. Biogas residues from four biogas plants were evaluated. Plants per m², ears per plant, grains per ear and thousand grain weight (TGW) were measured at harvest. Fertilization with BGRs resulted in similar biomass yields compared with mineral fertilizer. Mineral fertilizer (71 dt/ha) and plots fertilized with liquid fraction (59–62 dt/ha) indicated a trend to higher yields than solid fraction or complete BGR due to its high ammonia content. Liquid fractions and fraction with nitrification inhibitor induced fewer plants per m² than corresponding solid and complete variants due to a potential phytotoxicity of high NH4-N concentration during germination. However, barley on plots fertilized with liquid fraction compensated the disadvantages at the beginning during the vegetation period and induced higher grain yields than solid fraction. This was attributable to a higher number of ears per plant and grains per ear. In conclusion, BGRs from biodegradable municipal and industrial wastes can be used for soil fertilization and replace considerable amounts of mineral fertilizer. Our study showed that direct application of the liquid fraction of BGR is the most suitable strategy to achieve highest grain yields. Nevertheless potential phytotoxicity of the high NH4-N concentration in the liquid fraction should be considered. PMID:27116355

  14. Weathering and dissolution rates among Pb shot pellets of differing elemental compositions exposed to various aqueous and soil conditions.

    PubMed

    Takamatsu, Takejiro; Murata, Tomoyoshi; Koshikawa, Masami K; Watanabe, Mirai

    2010-07-01

    The present study was performed to investigate the weathering and dissolution rates of Pb shot pellets differing in elemental composition (Pb, Sb, and As) exposed under various aqueous and soil conditions using five commercial shot pellet preparations. Upon immersion in distilled water, the dissolution rates of shot pellets, calculated from the difference in weight before versus after immersion, decreased with increasing Sb + As contents and the dominant precipitate was hydrocerussite. These subsidiary ingredients may be related to the difficulty of metallic Pb oxidation (transformation to PbO). Weight losses standardized by the amount of rainfall upon exposure to rainfall on open grassland and under canopies of Japanese cedar (Cryptomeria japonica) and bamboo-leafed oak (Quercus myrsinaefolia) were 1.11, 1.07, and 7.35 mg g pellets(-1) year(-1) L(-1), respectively, and was also related to Sb + As contents in shot pellets. However, annual dissolution rates of Pb standardized by the amount of rainfall as the soluble fraction at the same sites were 0.72, 0.33, and 0.40 mg Pb g pellets(-1) year(-1) L(-1) in the same order. These trends seemed to be related to the rainfall pH, which induces precipitation of Pb dissolved as PbCO(3) under conditions of higher pH at the Q. myrsinaefolia site or organic matter released from leaves, etc., which can form metal complexes. Dissolution rates of shot pellets buried in soils (Cambisol, Fluvisol, Regosol, Andosol) also seemed to be related to the soil pH and dissolved organic matter contents but were about sixfold faster than those with exposure to rainfall. PMID:20039167

  15. Modeling the environmental fate of cadmium in a large wastewater irrigation area.

    PubMed

    Ingwersen, Joachim; Streck, Thilo

    2006-01-01

    The fate of cadmium in soils is governed by spatially heterogeneous processes that proceed from decades to centuries. This study aimed at modeling the fate of Cd within the wastewater irrigation area (WIA) of Braunschweig (Germany). The sandy soils (mainly Dystric Cambisol or Typic Haplumbrept) at this site (28 km2) have received considerable loads of heavy metals by irrigation of municipal wastewater for up to 40 yr. The soils of the WIA are in agricultural use. The main crops are sugar beet (Beta vulgaris L.), potato (Solanum tuberosum L.), and wheat (Triticum aestivum L.). As a result of asparagus (Asparagus officinalis L.) cropping, about 15% of the soils have been converted to Rigosols. In 1996, we measured the vertical distribution (0 to 1.2 m) of soil pH, organic carbon content, and the EDTA-extractable content and the solution phase concentration of Cd at 153 sites. At sites not used for asparagus cultivation, Cd has migrated on average to a depth of about 0.5 m. Due to deep plowing, which accelerates migration, Cd has been displaced on average to about 0.7 m at the Rigosol sites. To model the fate of Cd at the scale of the WIA, we used different parallel soil column approaches. In each column the local model SEFAH was used to simulate both displacement and plant uptake of Cd. The model was fed with measured or randomly generated soil data. The results of retrospective simulations from 1957 to 1996 agreed well with observed Cd profiles. The better the spatial variability of sorption was described, the better the performance. Our simulation results show that Cd pollution of soil at first affects the soil-plant pathway. The breakthrough of Cd to the groundwater is dampened and is delayed for many decades. PMID:16899742

  16. Response of soil microbial communities to fire and fire-fighting chemicals.

    PubMed

    Barreiro, A; Martín, A; Carballas, T; Díaz-Raviña, M

    2010-11-15

    Worldwide, fire-fighting chemicals are rapidly gaining acceptance as an effective and efficient tool in wildfires control and in prescribed burns for habitat management. However, despite its widespread use as water additives to control and/or slow the spread of fire, information concerning the impact of these compounds on soil ecosystems is scarce. In the present work we examine, under field conditions, the response of the microbial communities to three different fire-chemicals at normal doses of application. The study was performed with a Humic Cambisol over granite under heath, located in the temperate humid zone (Galicia, NW Spain) with the following treatments: unburned soil (US) and burned soil added with water alone (BS) or mixed with the foaming agent Auxquímica RFC-88 at 1% (BS+Fo), Firesorb at 1.5% (BS+Fi) and FR Cross ammonium polyphosphate at 20% (BS+Ap). The microbial mass (microbial C), activity (β-glucosidase, urease) and community structure [phospholipids fatty acids (PLFA) pattern] were measured on soil samples collected at different sampling times during a 5year period after a prescribed fire. The results showed a negative short-term effect of the fire on the microbial properties. The microbial biomass and activity levels tended to recover with time; however, changes in the microbial community structure (PLFA pattern) were still detected 5years after the prescribed fire. Compared to the burned soil added with water, the ammonium polyphosphate and the Firesorb treatments were the fire-fighting chemicals that showed a higher influence on the microbial communities over the whole study period. Our data indicated the usefulness of the PLFAs analysis to detect the long-term impact of both fire and fire-fighting chemicals on the soil microbial communities and hence on the soil quality of forest ecosystems. PMID:20888616

  17. Bruno Braunerde und die Bodentypen - The German-speaking friends of the Scottish soil characters

    NASA Astrophysics Data System (ADS)

    Hofmann, Anett

    2014-05-01

    Cartoon figures of soil profiles with faces, legs, arms and funny names: the Scottish soil characters Rusty (Cambisol), Heather (Podzol), Pete (Histosol) and five others were developed at the James Hutton Institute in Aberdeen for outreach activities. They represent eight soil types that are common in Scotland. Recently they have become movie stars in an animated film, where they speak with a Scottish accent. The Scottish soil characters are a true soil science communication success story and it would be great if they had friends in many places to tell some stories from the underground in the respective native languages. This contribution will introduce the draft for 13 German-speaking soil characters that represent the most common soil types in Austria, Germany and Switzerland. Each name is a play on words with respect to German soil classification terms and serves as a mnemonic for typical characteristics of these soils. The 'hair' shows detailed vegetation and the context with common land use. For non-soil scientists the soil characters can be used as story-tellers, e.g. about their life (soil evolution), home (spatial distribution), job (function), fears (threats) and joys (best-practice land use, restoration). Because the International Year of Soil (2015) is an excellent opportunity for new outreach activities, the aim is to publish the German-speaking soil characters as a collaboration of the Austrian, German and Swiss Soil Science Societies. The soil characters could be used in print or online formats, and even - as can be seen in Aberdeen - as human-sized walking soil profiles.

  18. Significant alteration of soil bacterial communities and organic carbon decomposition by different long-term fertilization management conditions of extremely low-productivity arable soil in South China.

    PubMed

    Xun, Weibing; Zhao, Jun; Xue, Chao; Zhang, Guishan; Ran, Wei; Wang, Boren; Shen, Qirong; Zhang, Ruifu

    2016-06-01

    Different fertilization managements of red soil, a kind of Ferralic Cambisol, strongly affected the soil properties and associated microbial communities. The association of the soil microbial community and functionality with long-term fertilization management in the unique low-productivity red soil ecosystem is important for both soil microbial ecology and agricultural production. Here, 454 pyrosequencing analysis of 16S recombinant ribonucleic acid genes and GeoChip4-NimbleGen-based functional gene analysis were used to study the soil bacterial community composition and functional genes involved in soil organic carbon degradation. Long-term nitrogen-containing chemical fertilization-induced soil acidification and fertility decline and significantly altered the soil bacterial community, whereas long-term organic fertilization and fallow management improved the soil quality and maintained the bacterial diversity. Short-term quicklime remediation of the acidified soils did not change the bacterial communities. Organic fertilization and fallow management supported eutrophic ecosystems, in which copiotrophic taxa increased in relative abundance and have a higher intensity of labile-C-degrading genes. However, long-term nitrogen-containing chemical fertilization treatments supported oligotrophic ecosystems, in which oligotrophic taxa increased in relative abundance and have a higher intensity of recalcitrant-C-degrading genes but a lower intensity of labile-C-degrading genes. Quicklime application increased the relative abundance of copiotrophic taxa and crop production, although these effects were utterly inadequate. This study provides insights into the interaction of soil bacterial communities, soil functionality and long-term fertilization management in the red soil ecosystem; these insights are important for improving the fertility of unique low-productivity red soil. PMID:26486414

  19. Water repellency in an Alpine forest soil and its impact on hydraulic characteristics under simulated climate change

    NASA Astrophysics Data System (ADS)

    Schwen, Andreas; Zimmermann, Michael; Lamparter, Axel; Woche, Susanne; Bachmann, Jörg

    2014-05-01

    The climate of Alpine environments is expected to change dramatically as a consequence of global climate change. In this ecologically sensitive environment, prolonged dry periods and an increased occurence of extreme rainfall events is forecasted by many climate change models. On the other hand, soil water repellency (SWR) is known to affect hydraulic processes in soils, particularly in acidic forest soils and as a consequence of prolonged dry periods. By changing the soil surface properties, SWR also changes the hydraulically effective properties of soils. The quantification of the spatial occurence and degree of hydrophobicity is a crucial prerequirement for ecological and hydrological impact assessment and developing new models. Therefore, the objective of the present study was to quantify soil water repellency in an Alpine forest with respect to its spatial variability and affected by different simulated climatic regimes. The study was accomplished in the Rosalian mountains, some 60 km south of Vienna, Austria. The vegetation was a mature beech forest and the soil was a Podsolic Cambisol over weathered granitic rock debris. As parts of the experimental plot were covered by plastic roofs and artificially irrigated, three different treatments were tested: Compared to the natural precipitation (control), the irrigation amount was reduced with two drought degrees (moderate and extreme). Within a small grid, 9 samples were taken per treatment in two depths (surface and 0.10 m). The contact angle was determined with the modified sessile drop method. Additionally, total and organic carbon contents and the hydraulic soil properties were quantified. Infiltration experiments were performed with a tension infiltrometer using water and ethanol. The results showed considerable water repellency with at least subcritical contact angles for all treatments. Contact angles increased to above 90 degree at the moderate and extreme drought treatments. Differences between intrinsic

  20. Soil erosion survey using remote sensing images

    NASA Astrophysics Data System (ADS)

    Jakab, Gergely; Kertész, Ádám; Madarász, Balázs; Pálinkás, Melinda; Tóth, Adrienn

    2016-04-01

    Soil erosion is one of the most effective soil degradation processes reducing crop production on arable fields significantly. It also leads to serious environmental hazards such as eutrophication, mud and flesh floods. Beyond the processes there is an urgent need to survey and descript the current degree of erosion of arable lands in order to provide adequate land use techniques and mitigate the harmful effects. Surveying soil erosion is a very time consuming process since soil loss and deposition take place next to each other resulting a rather diverse erosion pattern even within a plot. Remote sensing is a possible way to determine the degree of soil erosion without special efforts taken in the field. The application of images can provide high resolution erosion maps of almost any type of arable fields. The method is based on the identification of the origin of the surface soil layer, i.e. whether it represents an originally deeper laying horizon (e.g. B horizon), or the parent material. A case study was carried out on a Cambisol formed on loess parent material. The soil and the parent rock have various reflectance spectra in the visible range, so this strip was used for the investigations. For map creation "training sites" were used in ArcMap environment. The obtained results suggest that the method is highly effective and useful, however, other properties like moisture content and plant cover can limit automated application. In this case new training sites are needed. The study was supported by the National Research, Development and Innovation Office (NKFIH),), project Nr. 108755 and the support is gratefully acknowledged here. G. Jakab was supported by the János Bolyai Fellowship.

  1. Small scale variability of transport and composition of dissolved organic matter in the subsoil

    NASA Astrophysics Data System (ADS)

    Leinemann, Timo; Kalbitz, Karsten; Mikutta, Robert; Guggenberger, Georg

    2016-04-01

    Dissolved organic matter (DOM) is the most mobile fraction of carbon in the soil and connects the carbon-rich topsoil with the subsoil where translocated OM may get stabilized. The water flux in soil is highly heterogeneous, both temporarily and spatially. We, therefore, hypothesize that at high flow velocities, DOM can bypass possible mineral binding sites and microorganisms, thus leading to less degraded DOM under high flow velocities. To address this question, we investigated water and DOM fluxes in situ using segmented suction plates (4 x 4 segments on 24 x 24 cm) installed into three soil observatories at three depths (10 cm, 50 cm, and 150 cm) in a Podzolic Cambisol under Beech (Fagus sylvatica) near Hannover, Germany. To follow the transport of carbon from the litter layer through the soil, an in situ 13C-labelling experiment has been conducted in January 2015. Concentration of dissolved organic carbon (DOC) and DOM composition was analyzed using high temperature combustion and photometric methods. The amount of transported DOC decreased by ca. 80% from 10 to 50 cm depth and by 40% from 50 to 150 cm depth. Different flow patterns existed at the centimeter scale, which were stable over time for individual suction plate segments. The specific UV280 nm absorbance of DOM decreased with increasing soil depth. This indicates a selective loss of aromatic compounds. The influence of different flow regimes on the DOM quality became apparent in the subsoil samples (>50 cm depth) showing a correlation of increasing UV280 nm absorbance with increasing water flux. Together with juvenile DO14C up to 150 cm depth this can be an indication for the importance of preferential flow on carbon transport to subsoil.

  2. Carbosoil, a land evaluation model for soil carbon accounting

    NASA Astrophysics Data System (ADS)

    Anaya-Romero, M.; Muñoz-Rojas, M.; Pino, R.; Jordan, A.; Zavala, L. M.; De la Rosa, D.

    2012-04-01

    The belowground carbon content is particularly difficult to quantify and most of the time is assumed to be a fixed fraction or ignored for lack of better information. In this respect, this research presents a land evaluation tool, Carbosoil, for predicting soil carbon accounting where this data are scarce or not available, as a new component of MicroLEIS DSS. The pilot study area was a Mediterranean region (Andalusia, Southern Spain) during 1956-2007. Input data were obtained from different data sources and include 1689 soil profiles from Andalusia (S Spain). Previously, detailed studies of changes in LU and vegetation carbon stocks, and soil organic carbon (SOC) dynamic were carried out. Previous results showed the influence of LU, climate (mean temperature and rainfall) and soil variables related with SOC dynamics. For instance, SCS decreased in Cambisols and Regosols by 80% when LU changed from forest to heterogeneous agricultural areas. Taking this into account, the input variables considered were LU, site (elevation, slope, erosion, type-of-drainage, and soil-depth), climate (mean winter/summer temperature and annual precipitation), and soil (pH, nitrates, CEC, sand/clay content, bulk density and field capacity). The available data set was randomly split into two parts: training-set (75%), and validation-set (25%). The model was built by using multiple linear regression. The regression coefficient (R2) obtained in the calibration and validation of Carbosoil was >0.9 for the considered soil sections (0-25, 25-50, and 50-75 cm). The validation showed the high accuracy of the model and its capacity to discriminate carbon distribution regarding different climate, LU and soil management scenarios. Carbosoil model together with the methodologies and information generated in this work will be a useful basis to accurately quantify and understanding the distribution of soil carbon account helpful for decision makers.

  3. Estimating hydraulic conductivity of internal drainage for layered soils in situ

    NASA Astrophysics Data System (ADS)

    Mavimbela, S. S. W.; van Rensburg, L. D.

    2013-11-01

    The soil hydraulic conductivity (K function) of three layered soils cultivated at Paradys Experimental Farm, near Bloemfontein (South Africa), was determined from in situ drainage experiments and analytical models. Pre-ponded monoliths, isolated from weather and lateral drainage, were prepared in triplicate on representative sites of the Tukulu, Sepane and Swartland soil forms. The first two soils are also referred to as Cutanic Luvisols and the third as Cutanic Cambisol. Soil water content (SWC) was measured during a 1200 h drainage experiment. In addition soil physical and textural data as well as saturated hydraulic conductivity (Ks) were derived. Undisturbed soil core samples of 105 mm with a height of 77 mm from soil horizons were used to measure soil water retention curves (SWRCs). Parameterization of SWRC was through the Brooks and Corey model. Kosugi and van Genuchten models were used to determine SWRC parameters and fitted with a RMSE of less 2%. The SWRC was also used to estimate matric suctions for in situ drainage SWC following observations that laboratory and in situ SWRCs were similar at near saturation. In situ K function for horizons and the equivalent homogeneous profiles were determined. Model predictions based on SWRC overestimated horizons K function by more than three orders of magnitude. The van Genuchten-Mualem model was an exception for certain soil horizons. Overestimates were reduced by one or more orders of magnitude when inverse parameter estimation was applied directly to drainage SWC with HYDRUS-1D code. Best fits (R2 ≥ 0.90) were from Brooks and Corey, and van Genuchten-Mualem models. The latter also predicted the profiles' effective K function for the three soils, and the in situ based function was fitted with R2 ≥ 0.98 irrespective of soil type. It was concluded that the inverse parameter estimation with HYDRUS-1D improved models' K function estimates for the studied layered soils.

  4. Spatial variability of microbial activity and substrate utilization patterns in top- and subsoils under European beech

    NASA Astrophysics Data System (ADS)

    Niebuhr, Jana; Heinze, Stefanie; Mikutta, Robert; Mueller, Carsten W.; Preusser, Sebastian; Marschner, Bernd

    2014-05-01

    The role of subsoils in the global carbon cycle is poorly understood and probably underestimated. This is due to an incomplete understanding of processes and mechanisms that influence carbon storage and decomposition in deeper soil horizons. Microbial communities play an important role in these processes, as their presence, structure and function are crucial for the decomposition and/or stabilization of organic compounds. In this study, carried out in a European beech (Fagus sylvatica L.) forest on a podzolic Cambisol near Hannover, the spatial variability of microbial activity and substrate utilization patterns were investigated in the subsoil. For this purpose, samples were taken from regular grids at dm distances in three soil profiles of 1.85 m depth and 3.15 m length, totaling 192 soil samples. Activities of 9 extracellular enzymes of the C-, S-, P- and N-cycle were determined with a multi-substrate enzymatic assay and for substrate utilization patterns the MicroRespTM method was applied. The results showed a strong decline of microbial activity from topsoil to subsoil. Enzyme activities varied greatly at the dm scale. The correlation of the variability of both microbial activity and substrate utilization patterns with depth and soil parameters such as pH, soil water content, total and dissolved organic carbon was tested with a principal component analysis. Existing dependencies of the variabilities on these parameters help to verify the hypotheses that microbial activity is spatially highly variable in the subsoil and this variability is due to the existence of certain hot spots of substrate availability and that outside these 'hot spots' the microbial activity and thus the decomposition of SOM are mainly limited by substrate availability.

  5. Effect of cropland management and slope position on soil organic carbon pool at the North Appalachian Experimental Watersheds

    SciTech Connect

    Hao, Yueli; Lal, Rattan; Owens, Lloyd; Izaurralde, R Cesar C.; Post, W M.; Hothem, Daniel

    2002-12-01

    Soil organic matter is strongly related to soil type, landscape morphology, and soil and crop management practices. Therefore, long-term (15-36-years) effects of six cropland management systems on soil organic carbon (SOC) pool in 0-30 cm depth were studied for the period of 1939-1999 at the North Appalachian Experimental Watersheds (<3 ha, Dystric Cambisol, Haplic Luvisol, and Haplic Alisol) near Coshocton, OH, USA. Six management treatments were: (1) no tillage continuous corn with NPK (NC); (2) no tillage continuous corn with NPK and manure (NTC-M); (3) no tillage corn?soybean rotation (NTR); (4) chisel tillage corn?soybean rotation (CTR); (5) moldboard tillage with corn?wheat?meadow?meadow rotation with improved practices (MTR-I); (6) moldboard tillage with corn?wheat?meadow?meadow rotation with prevalent practices (MTR-P). The SOC pool ranged from 24.5Mgha?1 in the 32-years moldboard tillage corn (Zea mays L.)?wheat (Triticum aestivum L.)?meadow?meadow rotation with straight row farming and annual application of fertilizer (N:P:K = 5:9:17) of 56?112 kg ha?1 and cattle (Bos taurus) manure of 9Mg ha?1 as the prevalent system (MTR-P) to 65.5Mgha?1 in the 36-years no tillage continuous corn with contour row farming and annual application of 170?225 kgNha?1 and appropriate amounts of P and K, and 6?11Mgha?1 of cattle manure as the improved system (NTC-M).

  6. Effect of land use and land cover changes on carbon sequestration in vegetation and soils between 1956 and 2007 (southern Spain)

    NASA Astrophysics Data System (ADS)

    Muñoz-Rojas, M.; Jordán, A.; Zavala, L. M.; de la Rosa, D.; Abd-Elmabod, S. K.; Anaya-Romero, M.

    2012-04-01

    Land use has significantly changed during the last decades at global and local scale, while the importance of ecosystems as sources/sinks of C has been highlighted, emphasizing the global impact of land use changes. The aim of this research was to improve and test methodologies to assess land use and land cover change dynamics and temporal and spatial variability in C stored in soils and vegetation at a wide scale. A Mediterranean region (Andalusia, Southern Spain) was selected for this pilot study in the period 1956-2007. Land use changes were detected by comparison of data layers, and soil information was gathered from available spatial databases. Data from land use and land cover change were reclassified according to CORINE Land Cover legend, according to land cover flows reported in Europe. Carbon vegetation stocks for 1956 and 2007 were calculated by multiplying C density for each land cover class and area. Soil carbon stocks were determined for each combination of soil and land use type at different standard depths (0-25, 25-50 and 50-75 cm). Total current carbon stocks (2007) are 156.1 Tg in vegetation and 415 Tg in soils (in the first 75 cm). Southern Spain has supported intense land cover changes affecting more than one third of the study area, with significant consequences for C stocks. Vegetation carbon increased 17.24 Mt since 1956 after afforestation practices and intensification of agriculture. Soil C stock decreased mainly in Cambisols and Regosols (above 80%) after forest areas were transformed into agricultural areas. The methodologies and information generated in this project constitute a basis for modelling of C sequestration and analysis of potential scenarios, as a new component of MicroLEIS DSS. This study highlights the importance of land cover changes for C sequestration in Mediterranean areas, highlighting possible trends for management policies in Europe in order to mitigate climate change.

  7. Examining Sediment-bound Radiocesium Dynamics in Two Fukushima Coastal Catchments with Sediment Fingerprinting Techniques

    NASA Astrophysics Data System (ADS)

    Laceby, J. P.; Lepage, H.; Bonté, P.; Joron, J. L.; Onda, Y.; Lefèvre, I.; Ayrault, S.; Evrard, O.

    2015-12-01

    The Fukushima Dai-ichi nuclear power plant accident resulted in the significant fallout of radiocesium (137Cs and 134Cs) over the Fukushima region. After deposition on the soil surface, radiocesium is primarily bound to fine soil particles. Subsequently, rainfall and snow melt run-off events result in the downstream migration of radiocesium. Understanding the spatial distribution and relative contribution of different sediment sources is therefore fundamental to the management of radiocesium migration. Sediment fingerprinting techniques were used to determine the location and relative contributions of different sediment sources in the Mano and Niida Rivers, in the Fukushima region. First, we modelled the relative contributions of radiocesium from the upstream portions of the catchment, that received greater proportions of the fallout (e.g. >20 kBq kg-1), to sediment sampled in the downstream coastal regions. Second, we examined the elemental geochemistry of the major soil types (e.g. Andosols, Cambisols, Fluvisols) within these catchments and modelled their relative contribution to sediment sampled throughout these catchments. Elemental composition was measured with neutron activation analysis, radiocesium with gamma-spectrometry and a distribution modelling approach quantified source contributions. In the Mano River ~20% of the radiocesium sampled was modelled to be derived from the upstream area compared to ~50% in the Niida River. The highest contribution of upstream radiocesium was modelled after the typhoon seasons in 2011 and 2013. Fluvisols were found to be the dominant source of sediment (76%). The dominance of Fluvisols indicates that sediments are likely derived from sources that are highly connected to the river network (e.g. rice paddy fields). Understanding the relative contributions of these different sediment sources will allow for more direct management of sediment and thus radiocesium transfers in these Fukushima coastal catchments.

  8. Estimation on soil erosion dynamics using stable isotope ratios of soil organic matter

    NASA Astrophysics Data System (ADS)

    Jakab, Gergely; Zacháry, Dóra; Szalai, Zoltán; Ringer, Marianna; Szabó, Judit

    2016-04-01

    Stable isotopes are a powerful and widely used tool for tracing biogeochemical processes across the ecosystem. Measuring the stable carbon, oxygen and hydrogen isotope composition of CO2 and H2O compounds and organic matter is useful for examining the soil, plant and atmospheric carbon and water pools as they isotopic composition is altered during vegetation-soil-atmosphere exchange processes (e.g., evapotranspiration, carbon assimilation and respiration). Stable carbon and nitrogen isotopes can serve as a tracer for C and N input by plants into the soil, C turnover and soil organic matter studies. In addition, coupling of isotopic tracers with molecular biology approaches and biomarkers can lead to a better understanding of the soil ecosystem processes. This study aims to estimate soil erosion deposition and redistribution processes at catena scale on the basis of stable isotope results. Soil samples were taken from the total depth of the solum along two catenas on an intensively tilled arable Cambisol. Highest δC13 values were found on the most eroded spots, while on the deposition areas significant differences were measured among the sedimented layers. The lowest δC13 value was in the buried horizon at around 120 cm depth. From this horizon δC13 values slightly increased in both upward and downward directions. However the total organic carbon concentration was highly fluctuated in the deposited profiles and have not reached its maximum in this horizon isotope results suggest that this horizon could have been the original soil surface prior to the main erosion events. In this way the use of stable isotope changes in space can provide additional information on soil redistribution due to tillage erosion. National Hungarian Research Found K100180, G. Jakab was supported by the János Bolyai fellowship of the HAS.

  9. An analysis of the dissipation of pharmaceuticals under thirteen different soil conditions.

    PubMed

    Kodešová, Radka; Kočárek, Martin; Klement, Aleš; Golovko, Oksana; Koba, Olga; Fér, Miroslav; Nikodem, Antonín; Vondráčková, Lenka; Jakšík, Ondřej; Grabic, Roman

    2016-02-15

    The presence of human and veterinary pharmaceuticals in the environment is recognized as a potential threat. Pharmaceuticals have the potential to contaminate soils and consequently surface and groundwater. Knowledge of contaminant behavior (e.g., sorption onto soil particles and degradation) is essential when assessing contaminant migration in the soil and groundwater environment. We evaluated the dissipation half-lives of 7 pharmaceuticals in 13 soils. The data were evaluated relative to the soil properties and the Freundlich sorption coefficients reported in our previous study. Of the tested pharmaceuticals, carbamazepine had the greatest persistence (which was mostly stable), followed by clarithromycin, trimethoprim, metoprolol, clindamycin, sulfamethoxazole and atenolol. Pharmaceutical persistence in soils was mostly dependent on the soil-type conditions. In general, lower average dissipation half-lives and variability (i.e., trimethoprim, sulfamethoxazole, clindamycin, metoprolol and atenolol) were found in soils of better quality (well-developed structure, high nutrition content etc.), and thus, probably better microbial conditions (i.e., Chernozems), than in lower quality soil (Cambisols). The impact of the compound sorption affinity onto soil particles on their dissipation rate was mostly negligible. Although there was a positive correlation between compound dissipation half-life and Freundlich sorption coefficient for clindamycin (R=0.604, p<0.05) and sulfamethoxazole (R=0.822, p<0.01), the half-life of sulfamethoxazole also decreased under better soil-type conditions. Based on the calculated dissipation and sorption data, carbamazepine would be expected to have the greatest potential to migrate in the soil water environment, followed by sulfamethoxazole, trimethoprim and metoprolol. The transport of clindamycin, clarithromycin and atenolol through the vadose zone seems less probable. PMID:26657382

  10. Human impact on the geomorphic evolution of the HOAL catchment, Lower Austria

    NASA Astrophysics Data System (ADS)

    Pöppl, Ronald; Kraushaar, Sabine; Strauss, Peter; Fuchs, Markus

    2016-04-01

    Since the beginning of human settlement extensive land cover and land use changes have induced significant geomorphic landscape changes as water and sediment dynamics have been transformed. The presented project focuses on the reconstruction of Holocene geomorphic landscape evolution and the assessment of recent geomorphic processes in the Northern foothills of the Eastern Alps in Austria - an area intensively agriculturally used since the middle ages and often overlooked in its geomorphic evolution. The study area is a small catchment (ca. 66 ha) which is located in the western part of Lower Austria comprising a land use history as well as environmental settings typical for wide regions across the Northern foothills of the Eastern Alps in Austria. The catchment elevation ranges from 268 to 323 m a.s.l. and has a mean slope angle of 8%. The climate in this region can be characterized as humid. The lithology mainly consists of Tertiary marly to sandy deposits which are superimposed by Quaternary sediments (e.g. loesses). Dominant soil types are Cambisols, Luvisols, and Planosols. Furthermore, the catchment is used as a Hydrological Open Air Laboratory (HOAL) implemented for the long-term research of water-related flow and transport processes in the landscape (http://hoal.hydrology.at). The main objective of this research project is to reconstruct Holocene landscape evolution by analyzing physical parameters of sediment cores taken from colluvial and alluvial sediment archives with additional 14C and OSL dating as well as by the measurement of truncated and covered standardized Luvisol profiles. First results will be presented at the EGU General Assembly 2016.

  11. XANES spectroscopy as a tool to trace phosphorus transformation during soil genesis and mountain ecosystem development from lake sediments

    NASA Astrophysics Data System (ADS)

    Giguet-Covex, C.; Poulenard, J.; Chalmin, E.; Arnaud, F.; Rivard, C.; Jenny, J.-P.; Dorioz, J.-M.

    2013-10-01

    The aim of this study is to investigate phosphorus (P) species modifications triggered by soil genesis and mountain ecosystem development after glacial retreat using a lake sediment archive (Lake Anterne, North French Alps). Five lake sediment samples, representative of different stages of soil and ecosystem development, were selected for P speciation analyses. Furthermore, a sequence of current soils from the catchment was analyzed to better constrain our interpretations of the lacustrine archive. Synchrotron techniques (X-ray Fluorescence (XRF) mapping and P K-edge X-ray absorption near edge structure (XANES) spectroscopy) were applied to lake sediments, soils, and standards (mineral and organic) to distinguish between different P species. The results show that soil development during the first millennia of the Holocene triggered increased P species diversity. At the onset of the Holocene, P was present as apatite when rocks and leptosols dominated the catchment. Pedogenic processes then led to apatite dissolution and the formation of large amounts of P on metal/clay-organic complexes. P geochemistry during the main step of soil genesis (early leptosols dominated by apatite, low weathered cambisols with P mainly adsorbed on iron oxides, highly weathered podzols with large amounts of P on Al/Fe/clay organic complexes) is thus clearly recorded in lake sediments. P K-edge XANES spectroscopy is particularly relevant as qualitative method to study P species in soils and lake sediments at high spatial resolution. Such resolution is needed to reveal the diversity of small P particles and like this better characterize the P cycle and improve our understanding of ecosystem evolution.

  12. Circulating soluble leptin receptor and free leptin index during childhood, puberty, and adolescence.

    PubMed

    Kratzsch, J; Lammert, A; Bottner, A; Seidel, B; Mueller, G; Thiery, J; Hebebrand, J; Kiess, W

    2002-10-01

    Leptin is bound in human blood by a high affinity binding protein, which appears to be identical with the soluble leptin receptor (sOB-R). Using a ligand-mediated immunofunctional assay for the determination of serum sOB-R, we investigated its course during childhood, puberty, and adolescence in a large cohort of 581 healthy children and adolescents and a small group of 13 patients with anorexia nervosa. In the first years of life, sOB-R is detectable in remarkably high concentrations. Thereafter, a continuous decline of sOB-R levels was found. Consequently, correlation analyses demonstrated significant inverse relationships (P < 0.001) of sOB-R with age, IGF-I levels, pubertal stage, auxological and body composition parameters, as well as with leptin concentrations. Multiple regression analysis revealed that height, IGF-I, and age (only in girls) were independent predictors of sOB-R levels; these variables account for approximately 65% and 48% of the variation of sOB-R levels in boys and girls, respectively. The courses of age-dependent median values for the free leptin index (FLI, ratio between leptin and sOB-R levels) and for leptin levels were parallel in both genders. Correlation analyses demonstrated that in particular parameters of growth and sexual maturation are more closely related to the FLI than to leptin alone; this closer relationship is more pronounced among boys. Weight gains of patients with anorexia nervosa resulted in a significant increase in leptin and IGF-I levels (P < 0.01), whereas the median of sOB-R values decreased (P < 0.01). sOB-R and IGF-I levels were again significantly correlated (r = -0.55, P < 0.01). These findings suggest that high levels of sOB-R in emaciation may reflect an up-regulation of the sOB-R to suppress leptin action during energy deficiency. Furthermore, determinations of sOB-R and FLI are additional valuable tools to investigate the leptin axis during growth and sexual maturation. PMID:12364439

  13. Seminario Tecnico Regional Sobre Alternativas de Educacion Basica de Adultos en el Marco de la REDALF del Proyecto Principal de Educacion en America Latina y el Caribe (Colonia Tovar, Venezuela, 29 de Septiembre al 3 de Octubre, 1986). Documento Final. (Regional Seminar on Alternatives for Basic Adult Education in the REDALF Project for Education in Latin America and the Caribbean (Colonia Tovar, Venezuela, September 29-October 3, 1986). Final Document.)

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Santiago (Chile). Regional Office for Education in Latin America and the Caribbean.

    The final report of a conference concerning adult basic education de Adultos en el Marco de la REDALF del related to innovative projects in adult education in nine countries. A wide spectrum of issues related to adult basic education, curriculum, methodology, evaluation, and research are analyzed in the context of educational planning. Among the…

  14. Pasado, presente y futuro de la epidemiología. Una perspective latinoamericana

    PubMed Central

    Morabia, Alfredo

    2015-01-01

    Este artículo intenta contestar tres preguntas. Sobre el pasado: ¿Por qué no existió una epidemiología precolombina? Sobre el presente: ¿Cuáles son los orígenes de la epidemiología moderna, incluyendo sus raíces sudamericanas? Y sobre el futuro, escogí un título surrealista para enfatizar el hecho que estoy consciente de que es siempre delicado hacer predicciones: ¿Por qué fenómenos complejos son los “objetos oscuros del deseo” epidemiológico? PMID:25124247

  15. Explore medicamentos | Smokefree Español

    Cancer.gov

    Aprenda sobre los medicamentos que lo ayudarán a dejar de fumar, incluso el tratamiento de reemplazo de la nicotina. El uso de estos medicamentos puede duplicar sus probabilidades de dejar de fumar definitivamente.

  16. El estrés y fumar | Smokefree Español

    Cancer.gov

    Muchas personas fuman cuando se sienten estresadas. Una parte importante de dejar de fumar es encontrar maneras de manejar el estrés. Reciba recomendaciones sobre formas de disminuir el estrés en su vida.

  17. 26 CFR 31.6402(a)-2 - Credit or refund of tax under Federal Insurance Contributions Act or Railroad Retirement Tax Act.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... social security tax due to having received wages or compensation from multiple employers, the employee... Contribución Federal sobre el Trabajo por Cuenta Propia (Incluyendo el Crédito Tributario Adicional por...

  18. Polio Vaccine: What You Need to Know

    MedlinePlus

    ... Spanish and other languages. See www. immunize. org/ vis Hojas de información sobre vacunas están disponibles en ... en muchos otros idiomas. Visite www. immunize. org/ vis 1 Why get vaccinated? Vaccination can protect people ...

  19. Observing Sites in NW Argentina

    NASA Astrophysics Data System (ADS)

    Muriel, H.

    En esta comunicacion se propone revisar la importancia que los grandes relevamientos de galaxias y los diferentes catalogos que de ellos se derivan, tienen en los estudios sobre estructura y evolucion del Universo.

  20. Frequently Asked Questions about Genetic Testing

    MedlinePlus

    ... sobre las pruebas genéticas Frequently Asked Questions About Genetic Testing What is genetic testing? What can I ... find more information about genetic testing? What is genetic testing? Genetic testing uses laboratory methods to look ...

  1. Progreso con el "Telescopio de Nueva Tecnologia" de 3.5 m (NTT)

    NASA Astrophysics Data System (ADS)

    1982-09-01

    Desde septiembre de 1980 cuando el primer artlculo sobre el Telescopio ESO de Nueva Tecnologla de 3.5 m fue publicado en "EI Mensajero", el diserio para este instrumento ha hecho progresos satisfactorios.

  2. My Friend Is Talking about Suicide

    MedlinePlus

    ... Friend Who Cuts? My Friend Is Talking About Suicide. What Should I Do? KidsHealth > For Teens > My ... sobre suicidio. ¿Qué debo hacer? Warning Signs of Suicide Everyone feels sad, depressed, or angry sometimes — especially ...

  3. Tumores carcinoides gastrointestinales—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del tumor carcinoide gastrointestinal, así como referencias a estudios clínicos y otros temas relacionados.

  4. Celiac Disease: What You Need to Know

    MedlinePlus

    ... iniciativa del National Digestive Diseases Information Clearinghouse, un servicio del National Institute of Diabetes and Digestive and ... Nacional de Información sobre las Enfermedades Digestivas, un servicio del National Institute of Diabetes and Digestive and ...

  5. Carcinoma de tumor primario desconocido—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del carcinoma de tumor primario desconocido, así como referencias a estudios clínicos y otros temas relacionados.

  6. Muchos adolescentes y adultos jóvenes supervivientes de cáncer tienen problemas crónicos de salud

    Cancer.gov

    Artículo sobre los resultados de un estudio realizado en 2012 que subrayan la importancia de abordar las necesidades especiales e inquietudes de los adolescentes y adultos jóvenes supervivientes de cáncer.

  7. Neoplasias mieloproliferativas y síndromes mielodisplásicos—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento de las neoplasias mieloproliferativas, así como referencias a estudios clínicos y otros temas relacionados.

  8. Grados de comprobación de estudios de terapias integrales (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Información acerca de cómo sopesar la fuerza de los datos probatorios obtenidos de los estudios de investigación sobre terapias integrales, alternativas y complementarias en seres humanos con cáncer.

  9. 76 FR 73017 - Submission for OMB Review; Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-28

    ... Return; Form 1040-PR, Planilla Para La Declaracion De La Contribucion Federal Sobre El Trabajo Por Cuenta..., and provide credit to the taxpayer's social security account. Anejo H-PR is used to compute...

  10. Líneas Vitales: Programas y servicios del NCI

    Cancer.gov

    Artículos y videos sobre los programas y servicios del Instituto Nacional del Cáncer de la serie educativa Líneas Vitales del NCI, la cual está dirigida especialmente a poblaciones multiculturales.

  11. Leptin as well as Free Leptin Receptor Is Associated with Polycystic Ovary Syndrome in Young Women

    PubMed Central

    Rizk, Nasser M.; Sharif, Elham

    2015-01-01

    Background and Aim. Leptin has two forms in the circulation: free and bound forms. The soluble leptin receptor (sOB-R) circulates in the blood and can bind to leptin. The aim of this study is to assess the concentrations of the leptin and the sOB-R in PCOS and its relation to adiposity, insulin resistance, and androgens. Methods. A cross-sectional study included 78 female students aged 17–25 years. Fasting serum leptin and sOB-R concentrations were measured. The anthropometric variables and the hormonal profile such as insulin, female and male sex hormones, and prolactin were assessed. Results. In PCOS, leptin level (ng/ml) and free leptin index (FLI) increased significantly while sOB-R (ng/ml) significantly decreased compared to control subjects. In age-matched subjects, obese PCOS had increased leptin level in ng/ml (median level with interquartile levels) of 45.67 (41.98–48.04) and decreased sOB-R in ng/ml 11.47 (7.59–16.44) compared to lean PCOS 16.97 (10.60–45.55) for leptin and 16.62 (11.61–17.96) for sOB-R with p values 0.013 and 0.042, respectively. However, body mass index (BMI) is significantly correlated with leptin and s-OBR, while no significant correlations with parameters of insulin resistance were detected. Conclusion. PCOS is associated with hyperleptinemia and increased free leptin index. Decreased sOB-R could be a compensatory mechanism for the defective action of leptin. PMID:26180527

  12. Inventario mundial de la calidad del carbon mineral (WoCQI) [The world coal quality inventory (WoCQI)

    USGS Publications Warehouse

    Finkelman, R.B.; Lovern, V.S.

    2001-01-01

    Los oficiales encargados de la politica comercial de cada pais requieren informacion clara y precisa sobre el recurso del carbon mineral, particularmente sobre sus propiedades y caracteristicas, para tomar decisiones bien fundamentadas con respecto al mejor uso de los recursos naturales, necesidades de importacion y oportunidades de exportacion, objetivos de politica interna y externa, oportunidades de transferencia tecnologica, posibilidades de inversion externa, estudios ambientales y de salud, y asuntos relacionados con el uso de productos secundarios y su disposicion.

  13. Cuando uno de tus papás tiene cáncer

    Cancer.gov

    Sugerencias para saber qué decir a los amigos, cómo superar la tensión y en dónde encontrar apoyo; también, información sobre el cáncer y sobre los tratamientos de cáncer, para jóvenes que tienen a uno de sus papás con cáncer.

  14. Tracing subsoil organic matter compositional changes by radiocarbon and plant leaf wax distributional changes

    NASA Astrophysics Data System (ADS)

    John, Stephan; Angst, Gerrit; Mueller, Carsten W.; Heinze, Stefanie; Marschner, Bernd; Rethemeyer, Janet

    2014-05-01

    The carbon pool in subsoils is thought to be considerably larger than in the upper 30 cm. However, factors like turnover, stabilization and distribution of organic matter (OM) are less well understood than in topsoils. The investigation of changes in OM composition with depth enables a better understanding of the peculiarity of subsoil OM in contrast to the already extensively studied topsoil OM. Analysis of long chained n-alkanes and n-fatty acids in soil profiles sampled in high resolution, combined with radiocarbon data of bulk soil, is a tool to demonstrate spatial distribution and the degradation of plant leaf wax-derived material as a defined source of soil organic. We analysed the OM in 3.15 m long soil transects under an even aged European beech (Fagus sylvatica L.) forest in Northern Germany (Grinderwald, Lower Saxony) for lipid and radiocarbon analysis. Samples were taken from a grid raster with eight sampling points increasing in distance to the main tree (45cm grid dimension) and from five depths (10, 35, 60, 85, 110 cm) resulting 40 samples per transect. Organic carbon contents in the podzolic Cambisol decrease from 1.69 % in the A-horizon to 0.02 % in the C-horizon at 110 cm depth. The distribution of organic carbon contents shows no significant trend with increasing distance to the beeches in all transects. We compare the distribution of long-chain n-alkanes (C27, C29 and C31) and n-fatty acids (>C20), known as components mainly derived from leaf waxes of higher plants, in the different transect/depth intervals. Distributional and quantitative changes in the transects, combined with bulk soil 14C-analyses, reflecting apparent mean residence time of OM, are used to identify how fast OM is degraded from surface to subsoil horizons. Furthermore, spatial OM heterogeneity in the transects is investigated. We expect a more significant heterogeneity in the lipid distribution and nearly similar decreasing contents for n-alkanes as well as n-fatty acids

  15. Soil properties in different types of Eucalypt Plantations in a small forested watershed, north-central Portugal

    NASA Astrophysics Data System (ADS)

    Santos, J. M.; van Beersum, S.; van Hall, I.; Bernard-Jannin, L.; Rial-Rivas, M. E.; Nunes, J. P.; Keizer, J. J.

    2012-04-01

    The main aim of the HIDRIA project is to improve the knowledge and understanding of factors and processes that determine the hydrological behaviour of forested foothills in the Caramulo mountain range, North-Central Portugal. The changes from natural forest cover to Eucalyptus plantations in the last decades in Portugal is present in Serra de Cima catchment, one of the four experimental catchments monitored within the framework of the project. The objectives of the present study are to determine the effects of these changes on soil properties, and to improve the parameterization of the SWAT model to simulate the impact of land-use changes associated with forestry practices on hydrological processes. The study catchment (Serra de Cima) is located in the Águeda Basin, draining the foothills of the Caramulo mountains east of Águeda (40°36'N, -8°20'E). The climate is wet Mediterranean with a mean annual precipitation of about 1600 mm at 445 m a.s.l. Soils are generally Umbric Leptosols (<30 cm depth) and Humic Cambisols. The Serra de Cima catchment has an area of 0.52 km2 and is covered by commercial eucalypt plantations (73% of the total area) and natural/degraded pine forest (27% of the total area). Eucalypts are managed as Short Rotation Coppices, with each stand growing during 30-36 years; trees are cut every 10-12 years and stems re-grow from roots afterwards. The eucalypt stands in the study area differ in tree age, undergoing their first, second or third rotations. Climate, soil moisture and streamflow are monitored at the catchment. The presentation will focus on the results of a field campaign done on June 2011 to characterize soil and vegetation properties for six points on eucalypt stands in different stages of growth, as well as pine stands. The parameters sampled in this campaign were selected based on a sensitivity analysis of the SWAT model, and included: tree density and diameter; Leaf Area Index (LAI); ground cover; profile description; dry bulk

  16. Increased belowground C release during initial plant development of Populus deltoides x nigra grown under light and C reserve limited conditions

    NASA Astrophysics Data System (ADS)

    Studer, Mirjam S.; Siegwolf, Rolf T. W.; Schmidt, Michael W. I.; Abiven, Samuel

    2014-05-01

    Plants might be a key factor for the long-term stabilisation of carbon (C) in the soil, e.g. through enhanced physical protection of root-derived C against microbial decomposition in soil aggregates. On the other hand C released by the plants into the soil might promote the decomposition of native soil organic matter (SOM) through the stimulation of microbial activity. We measured the C budget of developing plant-soil systems (Populus deltoides x nigra, Cambisol soil) in the laboratory under controlled environmental conditions. In order to distinguish plant-derived from native C in the SOM and the soil CO2 efflux, we labelled the poplar shoots continuously with 13C-CO2 from first emergence of leaves (sprouting from stem cuttings). Throughout the experiment the CO2 fluxes (photosynthetic assimilation, dark respiratory loss, soil CO2 efflux) were measured frequently (every 30 min) and the 13C was traced in the soil CO2 efflux (1-2 times a week). After 10 weeks the plant-soil systems were destructively harvested and the distribution of the 13C distribution was analysed. The plants developed slowly (compared to previous experiments), most likely due to limitation in C reserves (long term cutting storage) and C supply (low light intensities). The amount of 13C recovered in the roots, microbial biomass and soil CO2 efflux was directly correlated with the leaf area of the different plant individuals. After 3-4 weeks of plant development we observed a high peak in the total soil CO2 efflux. During this time the relative belowground C release was increased massively over the basal rate of 17 % of net C assimilated, whereby the variability between the plant individuals was large. The smallest plants, i.e. the plants that were most resource limited, obtained the highest belowground C release accounting at the peak time for up to 57 % of net assimilated C. We hypothesize that the plants released specific compounds, which either directly (enzymatically) or indirectly (priming

  17. Carbon transfer, partitioning and residence time in the plant-soil system: a comparison of two 13C-CO2 labelling techniques

    NASA Astrophysics Data System (ADS)

    Studer, Mirjam S.; Siegwolf, Rolf T. W.; Schmidt, Michael W. I.; Abiven, Samuel

    2014-05-01

    13C-CO2 labelling is a powerful tool to study the carbon (C) dynamics in plant-soil systems, whereby various approaches have been applied, differing in the duration of label exposure, the applied label strength and the sampling intervals. We made a direct comparison of the two main 13C-CO2 labelling techniques - pulse and continuous labelling - and evaluated if different approaches yield the same results regarding the C transfer time, C partitioning and the C residence time in different plant-soil compartments. We conducted a pulse labelling (exposure to 99 atom% 13C-CO2 for three hours, traced for eight days) and a continuous labelling (exposure to 10 atom% 13C-CO2, traced for 14 days) on identical plant-soil systems (Populus deltoides x nigra, Cambisol soil) and under controlled environmental conditions. The plant-soil systems were destructively harvested at five sampling dates, and the soil CO2 efflux was sampled throughout the experiments. The 13C distribution into leaves, petioles, stems, cuttings, roots, soil, microbial biomass and soil respiration was analysed and wee applied exponential (pulse labelling) and logistic (continuous labelling) functions to model the C dynamics. Our results confirm that pulse labelling is best suited to assess the minimum C transfer time, while continuous labelling can be applied to assess the C transfer through a compartment, including short-term storage pools. Both experiments yielded the same C partitioning patterns at the specific sampling days, however, the time of sampling was crucial. For example the results of belowground C partitioning were consistent only after eight days of labelling. The C mean residence times estimated by the rate constant of the exponential and logistic function were largely different for the two techniques, mostly due to the strong model assumptions (e.g. steady state). Pulse and continuous labelling techniques are both well suited to assess C cycling. With pulse labelling, the dynamics of fresh

  18. Hydrochemistry, weathering and weathering rates on Madeira island

    NASA Astrophysics Data System (ADS)

    Van der Weijden, Cornelis H.; Pacheco, Fernando A. L.

    2003-12-01

    Madeira island consists of Miocene to Pleistocene lavas and pyroclasts. Major rock types are alkali-basalts, basanites and hawaiites; principal soil types are leptosols, andosols and cambisols. Our main objective was to link the chemistry of ground waters to weathering reactions and rates. We collected 40 shallow groundwater samples, remote from human activities. With a few exceptions, the ranges of electrical conductivities were 29-176 μS/cm and of pH 5.8-8.5. The calculated PCO 2 was generally higher than the atmospheric value. The contribution of sea salt to the water chemistry was 30±9%. Corrected for sea salt, the cation concentrations (in meq/l) decrease in the order Ca 2+≈Mg 2+>Na +>>>K +. The concentrations of SO 42- and NO 3- are very low. We calculated that the total annual chemical denudation rate in the studied area amounts to 37±12 g/m 2, consuming 0.86±0.38 mol CO 2/m 2. To achieve our main objective, a set of mole balance equations— ( AX= B)—was used, where A is a composite matrix of coefficients, including ratios between stoichiometric coefficients as determined by the weathering reactions and coefficients accounting for unconstrained contributions, B is the vector with a water composition, and X is the set of mole fractions of dissolved primary minerals plus the residual concentrations of the unconstrained contributions. Olivine (Ol), pyroxene (Py) and plagioclase (Pl) were considered to be the major primary minerals, and smectite, vermiculite, halloysite, allophane, gibbsite and hematite the secondary minerals in the weathering reactions. Using iterative procedures, whereby mixtures of secondary products as well as the composition of plagioclase are allowed to change, we selected one best-fit set of weathering reactions for each spring by checking all possible solutions of the mole balances against predefined boundary conditions. At odds with Goldich (1938) sequence, our model results indicate—for most best-fit sets—a weathering rate

  19. Determination of soil organic phosphorus exchange sensitivity

    NASA Astrophysics Data System (ADS)

    Shand, Charles; Wendler, Renate; Lumsdon, David; Cooper, Pat; George, Timothy; Brown, Lawrie; Giles, Courtney; Stutter, Marc; Menezes-Blackburn, Daniel; Zhang, Hao; Wearing, Catherine; Haygarth, Philip; Blackwell, Martin; Darch, Tegan

    2015-04-01

    Soils contain both organic and inorganic phosphorus (P) species in varying proportions. Studies have shown that many soils contain substantial amounts of inositol hexaphosphate (IHP) and there is much interest worldwide in developing strategies to make some use of this recalcitrant resource for plant growth to reduce P fertilizer inputs. Little is known about the preference of ion exchange processes in the solubilisation of organic vs inorganic P forms in soils, an important first step in making P forms bioavailable. Although they do not possess biotic functions, resins provides a simple means to deplete P forms in soil allowing investigation of exchange selectivity between inorganic and organic P forms. The aim of our work was to determine new understanding of exchange selectivity in soils and provide insight into potential depletion and plant uptake of soil phosphorus, with emphasis on organic forms such as IHP. For our study we used a Cambisol sampled from an agricultural area (Tayport) near Dundee in Scotland. The soil had a high Olsen (0.5 M sodium bicarbonate at pH 8.5) extractable P status (84 mg P/kg) and P-31 nuclear magnetic resonance analysis of its NaOH/EDTA extract showed it contained a substantial proportion of IHP (21 % of total extractable P). For resin extraction we used anion exchange resin sheets (4.17 cm each side) in bicarbonate form to minimise pH related solubilisation effects. We used 3.5 g of soil in 75 ml of water and added 1, 2 or 3 resin squares. After equilibration the resin squares were removed and replaced with fresh resin squares a further 3 times. Phosphorus was recovered from the resin sheets by elution with 0.25 M sulphuric acid and analysed by inductively coupled plasma spectroscopy to determine total P, and colorimetrically with malachite green to determine inorganic P with the remainder assigned to organic P. The data showed that the resin preferentially removed inorganic P and even after four sequential extractions little or

  20. Comparison of different landform classification methods for digital landform and soil mapping of the Iranian loess plateau

    NASA Astrophysics Data System (ADS)

    Hoffmeister, Dirk; Kramm, Tanja; Curdt, Constanze; Maleki, Sedigheh; Khormali, Farhad; Kehl, Martin

    2016-04-01

    The Iranian loess plateau is covered by loess deposits, up to 70 m thick. Tectonic uplift triggered deep erosion and valley incision into the loess and underlying marine deposits. Soil development strongly relates to the aspect of these incised slopes, because on northern slopes vegetation protects the soil surface against erosion and facilitates formation and preservation of a Cambisol, whereas on south-facing slopes soils were probably eroded and weakly developed Entisols formed. While the whole area is intensively stocked with sheep and goat, rain-fed cropping of winter wheat is practiced on the valley floors. Most time of the year, the soil surface is unprotected against rainfall, which is one of the factors promoting soil erosion and serious flooding. However, little information is available on soil distribution, plant cover and the geomorphological evolution of the plateau, as well as on potentials and problems in land use. Thus, digital landform and soil mapping is needed. As a requirement of digital landform and soil mapping, four different landform classification methods were compared and evaluated. These geomorphometric classifications were run on two different scales. On the whole area an ASTER GDEM and SRTM dataset (30 m pixel resolution) was used. Likewise, two high-resolution digital elevation models were derived from Pléiades satellite stereo-imagery (< 1m pixel resolution, 10 by 10 km). The high-resolution information of this dataset was aggregated to datasets of 5 and 10 m scale. The applied classification methods are the Geomorphons approach, an object-based image approach, the topographical position index and a mainly slope based approach. The accuracy of the classification was checked with a location related image dataset obtained in a field survey (n ~ 150) in September 2015. The accuracy of the DEMs was compared to measured DGPS trenches and map-based elevation data. The overall derived accuracy of the landform classification based on the

  1. Runoff generation and flow paths on an inclined cultivated soil

    NASA Astrophysics Data System (ADS)

    Zumr, David; Strouhal, Luděk; Kavka, Petr

    2015-04-01

    The hydrology of cultivated catchments has its specific features due to the temporary variable topsoil properties and a sharp divide between topsoil and compacted subsoil. Under various conditions (actual topsoil physical properties, initial soil saturation, rainfall characteristics, surface roughness or vegetation stage) the prevailing runoff mechanisms may vary from surface runoff to subsurface runoff or deep percolation. To investigate the runoff generation and flow pathways and to quantify the runoff components on an inclined cultivated field under various rainfall and field conditions we conducted plot scale rainfall simulations. The experiments were done on the experimental plots Bykovice in Central Bohemia (Czech Republic), where the soil is classified as Cambisol with a clear divide between the topsoil and compacted subsoil at a depth of approximately 14 cm. We used a mobile rainfall simulator (designed at the CTU in Prague) equipped with four solenoid-controlled nozzles positioned 2.65 m above the soil. An inclined experimental plot (8 x 2 m, 9% slope) was successively exposed to uniform simulated rainfall with intensity ranging from 23 to 64 mm h-1 and duration ranging from 1 h to 2.5 h. These simulated rainfall parameters were selected to represent intensive rainfall events observed in the study locality, to generate surface runoff and to initiate soil erosion. The dynamics of surface and shallow subsurface runoff and the soil water regime at three soil depths were monitored. Various initial soil moisture conditions, and vegetation stages; from cultivated fallow to stubble, delimited the simulations. Variable proportions of both monitored runoff components were observed in relation to rainfall intensity and duration, ranging from zero surface runoff to a distinct dominance of surface runoff. Both components reacted very dynamically to the precipitation: shallow subsurface runoff was formed first under all tested conditions on the given soil profile. Even

  2. Spatial analysis of subsoil compaction on cultivated land by means of penetrometry, electrical resistence tomography and X-ray computed tomography

    NASA Astrophysics Data System (ADS)

    Zumr, David; Vláčilová, Markéta; Dostál, Tomáš; Jeřábek, Jakub; Sobotková, Martina; Sněhota, Michal

    2015-04-01

    Soil compaction is a well recognized phenomena in the agricultural land. Various effects can alter the degree of the compaction in the field. The topsoil is regularly loosened due to agrotechnical operations, but the subsoil remains usually compacted. Various studies show increasing bulk density and decreasing saturated hydraulic conductivity in the plough pan, even though some authors argue that it does not have to be always the case due to presence of bio-macropores. Hence the structural properties of the subsoil and the spatial distribution of the compacted layer depth within the cultivated fields are important factors influencing soil water regime, nutrients regime and runoff generation. The aim of the contribution is to present the results of the monitoring of the plough pan depth spatial distribution at the experimental catchment Nucice (Central Bohemia, Czech Republic). The soils are classified as Luvisols and Cambisols with a loamy Ap horizon (0.1 - 0.2 m deep) underlined by a silty and silty-clay B horizon. The content of clay particles in the topsoil is around 8%. The soil has low inner aggregate (soil matrix) hydraulic conductivity, with measured values of approximately 0.1 - 2 cm d-1. The bulk topsoil saturated hydraulic conductivity (Ks) is significantly higher and varies depending on the season. To observe the divide between topsoil and subsoil layers in detail and to be able to compare the soil structure and pore networks of both layers we inspected undisturbed soil samples with X-ray computed tomography. The divide between the conservatively tilled topsoil and the subsoil is clearly observable also on terrain. To identify its exact position we implemented a combination of penetrometry, soil sampling and electrical resistance tomography (ERT). The penetration tests accompanied by soil probing were done in an irregular network across the whole catchment based on the slopes and distance to the stream. Several 2D ERT measurements were done locally on a

  3. Soil formation and mass fluxes in cover beds of the Kowarski Grzbiet (eastern Karkonosze Mountains)

    NASA Astrophysics Data System (ADS)

    Waroszewski, Jaroslaw; Egli, Markus; Brandová, Dagmar; Plötze, Michael; Kabala, Cezary; Kierczak, Jakub

    2014-05-01

    The Karkonosze Mountains are a Hercynian mid-mountain range located in the Central Europe, at the border of Poland and the Czech Republic. Although granite is the dominant geology in the western and middle part of the mountain belt, the eastern part consists mainly of different types of the schists and gneiss. Small mountain glaciers that developed during the late Weichselian, periglacial conditions as well as an intense activity of slope processes during the Atlantic and at the Atlantic/Sub-Boreal transition have shaped the landscape during the Quaternary and formed sequences of cover beds which became the main parent material of soils. In our study we focused on the eastern, metamorphic part that is characterised by mica schist, amphibole schist and gneiss. A transect was studied along the slope of Skalny Stol (1281 m as.l) of the Kowarski Grzbiet having NW exposition. This transect included 5 profiles along a slope section from 1269 m asl to 1142 m asl. In all profiles, at least three layers could be distinguished: (a) a basal layer formed probably in the Younger Dryas with features of solifluction - found in almost every relief position (b) a transition periglacial zone, interpreted as a result of cryoturbation, and (c) a top cover having almost no rock fragments and most likely relatively young (Holocene) appeared in all profiles. However, in some soils, colluvial material was found in the topsoil. Within the stony cover bed, at the flat plateaus and in the upper section of slope Hyperskeletic and Skeletic Podzols have developed (the basal and transition layer contained amphibole schist and the top layer only mica schist). In the middle and lower slope position where gelisolifluction layers were detected, colluvial material was superimposed and as a consequence Cambisols and Stagnosols have developed. Consequently, the soil distribution pattern in this landscape is strongly affected by the arrangement of the slope deposits. Sediments having a different age and

  4. Carbon transfer, partitioning and residence time in the plant-soil system: a comparison of two 13CO2 labelling techniques

    NASA Astrophysics Data System (ADS)

    Studer, M. S.; Siegwolf, R. T. W.; Abiven, S.

    2013-10-01

    Various 13CO2 labelling approaches exist to trace carbon (C) dynamics in plant-soil systems. However, it is not clear if the different approaches yield the same results. Moreover, there is no consistent way of data analysis to date. In this study we compare with the same experimental setup the two main techniques: the pulse and the continuous labelling. We evaluate how these techniques perform to estimate the C transfer velocity, the C partitioning along time and the C residence time in different plant-soil compartments. We used identical plant-soil systems (Populus deltoides x nigra, Cambisol soil) to compare the pulse labelling approach (exposure to 99 atom% 13CO2 for three hours, traced for eight days) with a continuous labelling (exposure to 10 atom% 13CO2, traced for 14 days). The experiments were conducted in climate chambers under controlled environmental conditions. Before label addition and at four successive sampling dates, the plant-soil systems were destructively harvested, separated into leaves, petioles, stems, cuttings, roots and soil and the microbial biomass was extracted from the soil. The soil CO2 efflux was sampled throughout the experiment. To model the C dynamics we used an exponential function to describe the 13C signal decline after pulse labelling. For the evaluation of the 13C distribution during the continuous labelling we suggest to use a logistic function. Pulse labelling is best suited to assess the maximum C transfer velocity from the leaves to other compartments. With continuous labelling, the mean transfer velocity through a compartment, including short-term storage pools, can be observed. The C partitioning between the plant-soil compartments was similar for both techniques, but the time of sampling had a large effect: shortly after labelling the allocation into leaves was overestimated and the soil 13CO2 efflux underestimated. The results of belowground C partitioning were consistent for the two techniques only after eight days of

  5. Carbon transfer, partitioning and residence time in the plant-soil system: a comparison of two 13CO2 labelling techniques

    NASA Astrophysics Data System (ADS)

    Studer, M. S.; Siegwolf, R. T. W.; Abiven, S.

    2014-03-01

    Various 13CO2 labelling approaches exist to trace carbon (C) dynamics in plant-soil systems. However, it is not clear if the different approaches yield the same results. Moreover, there is no consistent way of data analysis to date. In this study we compare with the same experimental setup the two main techniques: pulse and continuous labelling. We evaluate how these techniques perform to estimate the C transfer time, the C partitioning along time and the C residence time in different plant-soil compartments. We used identical plant-soil systems (Populus deltoides × nigra, Cambisol soil) to compare the pulse labelling approach (exposure to 99 atom % 13CO2 for three hours, traced for eight days) with a continuous labelling (exposure to 10 atom % 13CO2, traced for 14 days). The experiments were conducted in climate chambers under controlled environmental conditions. Before label addition and at four successive sampling dates, the plant-soil systems were destructively harvested, separated into leaves, petioles, stems, cuttings, roots and soil and soil microbial biomass was extracted. The soil CO2 efflux was sampled throughout the experiment. To model the C dynamics we used an exponential function to describe the 13C signal decline after pulse labelling. For the evaluation of the 13C distribution during the continuous labelling we applied a logistic function. Pulse labelling is best suited to assess the minimum C transfer time from the leaves to other compartments, while continuous labelling can be used to estimate the mean transfer time through a compartment, including short-term storage pools. The C partitioning between the plant-soil compartments obtained was similar for both techniques, but the time of sampling had a large effect: shortly after labelling the allocation into leaves was overestimated and the soil 13CO2 efflux underestimated. The results of belowground C partitioning were consistent for the two techniques only after eight days of labelling, when the

  6. Metabolic fate of the (14)C-labeled herbicide clodinafop-propargyl in soil.

    PubMed

    Jaquet, Jasmin; Weitzel, Pascal; Junge, Thorsten; Schmidt, Burkhard

    2014-01-01

    The metabolic fate of (14)C-phenyl-labeled herbicide clodinafop-propargyl (CfP) was studied for 28 days in lab assays using a soil from Germany (Ap horizon, silt loam, and cambisol). Mineralization amounted to 12.40% of applied (14)C after 28 days showing a distinct lag phase until day 7 of incubation. Portions of radioactivity extractable by means of 0.01 M CaCl2 solution (bioavailable fraction) decreased rapidly and were 4.41% after 28 days. Even immediately after application, only 57.31% were extracted with the aqueous solvent. Subsequent extraction using accelerated solvent extraction (ASE; acetonitrile/water 4:1, v/v) released 39.91% of applied (14)C with day 0 and 26.16% with day 28 of incubation from the samples. Non-extractable portions of radioactivity thus, increased with time amounting to 11.99% (day 0) and 65.00% (day 28). A remarkable increase was observed between 14 and 28 days correlating with the distinct increase of mineralization. No correlation was found throughout incubation with general microbial activity as determined by DMSO reduction. Analysis of the CaCl2 and ASE extracts by radio-TLC, radio-HPLC and GC/MS revealed that CfP was rapidly cleaved to free acid clodinafop (Cf), which was further (bio-) transformed; DT50 values (based on radio-TLC detection of the parent compound) were far below 1 day (CfP) and about 7 days (Cf). TLC analysis pointed to 2-(4-hydroxyphenoxy)-propionic acid as further metabolite. Due to fractionation of non-extractable residues, most of the (14)C was associated with fulvic and humic acids, portions in humin fractions and non-humics were moderate and low, respectively. Using a special strategy, which included pre-incubation of the soil with CfP and then mineralization of (14)C-CfP as criterion, a microorganism was isolated from the soil examined. The microorganism grew using CfP as sole carbon source with concomitant evolution of (14)CO2. The bacterium was characterized by growth on commonly used carbon

  7. What about the regolith, the saprolite and the bedrock? Proposals for classifying the subsolum in WRB

    NASA Astrophysics Data System (ADS)

    Juilleret, Jérôme; Dondeyne, Stefaan; Hissler, Christophe

    2014-05-01

    qualifiers pertaining to bedding, cleavage, fractures and lithological features could also be considered. These definitions will be particularly useful for giving more precise information of Reference Soil Groups representing shallow and/or poorly weathered soils such as the Cambisols, Regosols and Leptosols. Our definitions should contribute to better recording and classifying information on the soil to subsoil continuum, and doing so, improve the usefulness of soil survey data in environmental applications.

  8. Airborne geophysical surveys in the north-central region of Goias (Brazil): implications for radiometric characterization of tropical soils.

    PubMed

    Guimaraes, Suze Nei P; Hamza, Valiya M; da Silva, Joney Justo

    2013-02-01

    Progress obtained in analysis aerogammaspectrometric and aeromagnetic survey data for the north-central region of the state of Goias (Brazil) are presented. The results obtained have allowed not only determination of the abundances of naturally radioactive elements but also new insights into the processes that determine the radiometric characteristics of the main soil types. There are indications that the radioelement abundances of soils are not only related to their physical properties, but also chemical characteristics of source rocks from which they are derived. For example, oxisol soils derived from the felsic source rocks of the Mara Rosa and Green stone belts have equivalent uranium (eU) values higher than 1.7 ppm, while those derived from source rocks of the relatively more basic Uruaçu Group and sediment sequences of Proterozoic age are characterized by eU contents of less than 1 ppm. Oxisol soils of the Median massif, ultisol soils of the Paranoá, Canastra and Araxá Groups, cambisol soils of the Araí Group and plintosol soils of the Bambuí Group constitute an intermediate class with eU contents in the range of 1-1.3 ppm. Equivalent thorium abundances of soil types display similar trends, the range of variation being 4-16 ppm. Potassium abundances on the other hand are rather uniform with values in the range of 1-1.3%, the only exception being the sedimentary sequences of Proterozoic age, which has a mean value of 0.7%. These observations have been considered as indicative of characteristic features of tropical soils in the study area. In this context, we point out the possibility of using results of aerogammaspectrometry surveys as a convenient complementary tool in identifying geochemical zoning of soils in tropical environments. The ratios of eU/K are found to fall in the range of 1-1.7, which is typical of common soils. The ratios of eTh/K exhibit a relatively wide interval, with values in the range of 4-16. The ratios of eTh/eU are found to have

  9. The sorption characteristics of mercury as affected by organic matter content and/or soil properties

    NASA Astrophysics Data System (ADS)

    Šípková, Adéla; Šillerová, Hana; Száková, Jiřina

    2014-05-01

    The determination and description of the mercury sorption extend on soil is significant for potential environmental toxic effects. The aim of this study was to assess the effectiveness of mercury sorption at different soil samples and vermicomposts. Mercury interactions with soil organic matter were studied using three soils with different physical-chemical properties - fluvisol, cambisol, and chernozem. Moreover, three different vermicomposts based on various bio-waste materials with high organic matter content were prepared in special fermentors. First was a digestate, second was represented by a mixture of bio-waste from housing estate and woodchips, and third was a garden bio-waste. In the case of vermicompost, the fractionation of organic matter was executed primarily using the resin SuperliteTM DAX-8. Therefore, the representation of individual fractions (humic acid, fulvic acid, hydrophilic compounds, and hydrophobic neutral organic matter) was known. The kinetics of mercury sorption onto materials of interest was studied by static sorption experiments. Samples were exposed to the solution with known Hg concentration of 12 mg kg-1 for the time from 10 minutes to 24 hours. Mercury content in the solutions was measured by the inductively coupled plasma mass spectrometry (ICP-MS). Based on this data, the optimum conditions for following sorption experiments were chosen. Subsequently, the batch sorption tests for all soil types and vermicomposts were performed in solution containing variable mercury concentrations between 1 and 12 mg kg-1. Equilibrium concentration values measured in the solution after sorption and calculated mercury content per kilogram of the soil or the vermi-compost were plotted. Two basic models of sorption isotherm - Langmuir and Freundlich, were used for the evaluation of the mercury sorption properties. The results showed that the best sorption properties from studied soil were identified in chernozem with highest cation exchange

  10. Effect of farmyard manure rate on water erosion of a Mediterranean soil: determination of the critical point of inefficacy

    NASA Astrophysics Data System (ADS)

    Annabi, Mohamed; Bahri, Haithem; Cheick M'Hamed, Hatem; Hermessi, Taoufik

    2016-04-01

    Intensive cultivation of soils, using multiple soil tillage, led to the decrease of their organic matter content and structural stability in several cultivated area of the Mediterranean countries. In these degraded soils, the addition of organic products, traditionally the animal manure, should improve soil health among them the resistance of soil to water erosion. The aim of this study was to evaluate after 1 year of the addition to a cambisoil different doses of farmyard manure on soil organic matter content, on microbial activity and on aggregate stability (proxy to soil resistance to water erosion). The statistical process (bilinear model) was used to found a point at which the addition of the organic product no longer influences the soil resistance to erosion. The farmyard manure issued from a cow breeding was composted passively during 4 months and used to amend a small plots of a cultivated cambisol (silty-clay texture, 0.9% TOC) located in the northeast of Tunisia (Morneg region). The manure was intimately incorporate to the soil. The manure organic matter content was 31%, and its isohumic coefficient was 49%. Twelve dose of manure were tested: from 0 to 220 t C.ha-1. The experiment was started on September 2011. In November 2012, soil sampling was done and soil organic carbon content (Walkley-Black method) and soil aggregate stability (wet method of Le Bissonnais) were assessed. A laboratory incubations of soil+manure mixtures, with the same proportions as tested in the field conditions, was carried at 28°C and at 75% of the mixture field capacity water retention. Carbon mineralization was monitored during three months incubation. Results show that the addition of farmyard manure stimulated the microbial activity proportionally to the added dose. This activation is due to the presence of easily biodegradable carbon in the manure, which increases with increasing manure dose. On the other hand, the addition of manure increased the aggregate stability with

  11. Extracellular enzyme activities in a tropical mountain rainforest region of southern Ecuador affected by low soil P status and land-use change

    NASA Astrophysics Data System (ADS)

    Tischer, Alexander; Blagodatskaya, Evgenia; Ute, Hamer

    2014-05-01

    Little is known about the enzymatic response of microorganisms in soils having a low P status and being subjected to global change phenomena, such as forest disturbance and land-use change. Along a land-use sequence (natural forest - young pasture - old pasture - abandoned pasture - shrubland) in the Andes of southern Ecuador mineral topsoils of Cambisols / Umbrisols were investigated. We tested whether the activities of the six hydrolytic enzymes (cellobiohydrolase, β-glucosidase, N-acetylglucosaminidase, α-glucosidase, xylanase, acid phosphomonoesterase) were affected by nutrient status and land-use induced alterations in soil pH (pHH2O from 3.7 to 5.2), resource quantity and quality (e.g. a SOC:N:P ratio from 182:13:1 to 1050:38:1) and microbial community structure (as monitored by phospholipid fatty acids). Microbial production of acid phosphatase responded to the low P status of the sites by a higher investment in the acquisition of P compared to C. We determined three major drivers of enzyme activities: 1.) Microbial demand for P regulated the production of acid phosphatase, provided that N and C were available. At the natural forest site the two-fold higher specific activity of acid phosphatase pointed to a high microbial P-demand, whereas the production of acid phosphatase was constrained by the availability of N and DOC after pasture abandonment. 2.) Microbial biomass that was controlled by pH and resource availability (total soil N (organic and inorganic N), organic P (Bray-fraction)) was the main driver for cellobiohydrolase, β-glucosidase and N-acetylglucosaminidase activities. 3.) Substrate induction due to increased litter inputs of herbaceous plant species seemed to regulate α-glucosidase and xylanase activities during secondary succession. In contrast, alterations in the abundance of microbial groups affected the variation in extracellular enzyme activities only marginally. At the level of broadly defined microbial groups (PLFA), our results

  12. Source and compositional changes of soil organic matter in an acidic forest soil - from top- to subsoil

    NASA Astrophysics Data System (ADS)

    Angst, Gerrit; John, Stephan; Rethemeyer, Janet; Kögel-Knabner, Ingrid; Mueller, Carsten W.

    2014-05-01

    Subsoils can significantly contribute to the terrestrial C pool. While processes of C turnover and storage in topsoils are generally well understood, little is known about subsoils. Our project, embedded within the DFG research group FOR 1806, aims to contribute to the knowledge about subsoil C by differentiating soil organic matter (SOM) in terms of its origin and its composition. In order to obtain a meaningful sample set we studied three soil ditches, 3.15 m in length and 2.15 m in depth, in a podzolic Cambisol under European beech (Fagus sylvatica L.) north of Hannover, Germany. In a to date unique sampling approach we took 64 soil samples in a regular vertical grid in each of the soil profiles, thus identifying possible gradients between top- and subsoil. The samples were subjected to a combined density and particle size fractionation to separate particulate organic matter (POM) from mineral compartments. We especially aimed at obtaining the combined fine silt and clay fraction which is thought to be most important in the long term stabilization of SOM. The chemical composition of the so obtained fractions and the bulk soil was revealed by C, N and 13C CPMAS NMR measurements. The source of OM in the soil was investigated by tracing the biopolymers cutin and suberin across the soil profile. Cutin occurs mainly in the cuticula of leaves while suberin mainly constitutes the endodermal cell walls of plant roots. In soils the two polymers can thus be used as proxies for above and belowground OM input respectively. To release the constituting monomers of the two biopolymers from the soil samples the latter were pretreated with organic solvents to extract free lipids. The soil residues were subsequently subjected to a base hydrolysis and the so obtained extracts were measured with GC/MS. The organic C contents of the bulk soil decrease significantly with depth in all transects from around 15 mg g-1 to 2 mg g-1. This is likely associated with the very high sand and

  13. Effect of inter-row cultivation on soil CO2 emission in a peach plantation

    NASA Astrophysics Data System (ADS)

    Tóth, E.; Farkas, Cs.; Gelybó, Gy.; Lagzi, I.

    2012-04-01

    We examined the effect of inter-row cultivation on soil CO2 emission in a peach plantation planted in 1991. The soil is Ramann type brown forest soil /Mollic Cambisol/ developed on sandy loam. Every second row in the orchard is covered with undisturbed grass, and every other row is disked (depth: 12-15cm) with a two-three-week frequency. The humus content varies from 1,69% to 2,28% in the upper 20 cm layer, where the sand, loam and clay contents are 58%, 21% and 19 %, respectively. The average annual precipitation total is 570 mm (330 mm for the growing season) at the site. During the vegetation period of 2009 soil CO2 emission measurements were carried out with static chamber method in the differently managed rows. Parallel with CO2 measurements soil volumetric water content and soil temperature were also determined. Soil microbiological properties water-extractable organic carbon (WEOC) and water-extractable nitrogen (WEN) as well as substrate-induced respiration (SIR) were determined from disturbed soil samples collected on the first measurement day. The measured soil physical properties showed that different soil management practices influence soil water content, bulk density and soil temperature as well. Soil water content was higher in the grass covered row on 10 of the 13 measurement days, the difference - which reached 10 v% - was the highest on the warmest days. Soil temperature is also different in case of disked and grass covered rows, found to be lower in the grass covered rows on every measurement days. SIR, WEOC and WEN were all higher in the grass covered row (19.45 μg CO2-C g-1 soil 36.91 μg g-1 soil, 139.36 μg g-1 soil, respectively) than in the disked row (4.88 μg CO2-C g-1 soil 25.43 μg C g-1 soil, 61.25 μg N g-1 soil, respectively) in 2009. Soil CO2 emission also differed between the two rows, grass covered rows produced higher emission in all measurements days without exemption. The difference between CO2 fluxes from the two cultivation

  14. Seasonal variability of near-saturated hydraulic conductivity on cultivated soil

    NASA Astrophysics Data System (ADS)

    Klípa, Vladimír; Zumr, David; Sněhota, Michal

    2014-05-01

    The soil structure and hydraulic properties of arable soils considerably vary during the year due to the periodical tillage and fertilization activities, soil compaction, plant and root grow, climate impact etc. The knowledge of the effect of temporal soil variability is essential when assessing water regime and associated dissolved substance transport in soils. The main aim of this contribution is to describe the temporal development of unsaturated hydraulic conductivity on arable land during a year. The experimental site is located in Nucice catchment (Central Bohemia, Czech republic), where also rainfall-runoff and soil erosion processes are studied. The soil is classified as Cambisol, typical texture ranges from loam to clay loam classes. Soil is conservatively tilled till depth of approximately 17 cm, below the topsoil a compacted subsoil was observed. Tension infiltration experiments were performed repeatedly at single location in order to determine the unsaturated hydraulic conductivity of the topsoil. So far four tension infiltration campaigns were carried out under tension h0 = -3.0 cm with different field conditions: (i) young winter barley (October 2012), (ii) between postharvest stubble breaking and seeding (April 2013), (iii) full-grown oat (June 2013) and (iv) after fresh postharvest stubble breaking (October 2013). Measurements were carried out using newly introduced automated multi minidisk tension infiltrometer (Klipa et al., EGU2014-7230). All experiments were performed on the levelled soil surface after removing upper soil layer (1 to 3 cm). A thin layer of quartz sand (thickness 1 - 2 mm, grain size 0.1 - 0.6 mm) was applied to improve contact between the infiltrometer and the soil surface. Each infiltration campaign consisted of six tension infiltration experiments, the total number of 24 infiltration data sets was obtained for this study. Results show that unsaturated hydraulic conductivity was significantly smaller in April, but rather the

  15. Linking the field to the stream: soil erosion and sediment yield in a rural catchment, NW Spain

    NASA Astrophysics Data System (ADS)

    Rodriguez-Blanco, M. L.; Taboada-Castro, M. M.; Palleiro-Suarez, L.; Taboada-Castro, M. T.

    2009-04-01

    Quantifying the linkages between field erosion, fluvial response and catchment sediment yield remains problematic, among other reasons, because of the re-deposition of eroded sediment within the catchment, which is controlled by the spatial organization of the land use and the connectivity between sediment sources and the stream network. This paper presents the results of an integrated study that considered the relationship between erosion and stream sediment yield in an agroforestry catchment (16 km2) in NW Spain. The geology consists of basic metamorphic schist. The relieve of the area is steeper, the mean slope is approximately 19%. Main soil types are classified as Umbrisol and Cambisol. Soils are acidic and rich in organic matter. The soil texture is silt and silt-loam. Land cover consists of a mixture of forest (65%) and agricultural fields (mainly grassland, pasture and maize). The study combined measurements of soil erosion by concentrate flow and sediment deposition at field scale with sediment yield measured at the catchment outlet. The hydrological data and water samples were obtained at the catchment outlet. Stream water level was monitored continuously and converted to discharge using a rating curve. The sampling for suspended sediments was supplemented by an automatic sampler. Suspended sediment load was calculated from the suspended sediment concentrations and discharge data. Eroded volume was calculated from cross-sections (measured at specific points, where the section changed abruptly) and length of the channel segments. The total sediment delivered to stream was determined as the difference between all erosion features (rills and gullies) and the sediment volumes that were deposited on the fields. The results showed that in the catchment during the period winter 2007/08 soil erosion by concentrate flow, i.e. rills and ephemeral gullies, occurred on unprotected crop field. Erosion by concentrate flow was highly discontinuous within the catchment

  16. Hyperspectral remote sensing for soil organic carbon mapping

    NASA Astrophysics Data System (ADS)

    Stevens, A.; van Wesemael, B.

    2009-04-01

    Satellite and airborne hyperspectral remote sensing is increasingly investigated as a fast and convenient tool to map soil properties. However, several research have pointed out the difficulty to obtain good calibration results over large areas due to spatial variation in soil types and surface soil conditions (moisture content, roughness, vegetation cover). These effects induce a spectral variability not directly related to the property studied and decrease the accuracy of predictions. A flight campaign was organized on 4-9th October 2007 using the AHS-160 airborne spectrometer to predict Soil Organic Carbon (SOC) in bare cropland soils in Grand-Duchy of Luxembourg. The study area consisted in a north-south transect of ~7 km width and ~60 km length and crossed 4 of the 5 agro-geological regions of Luxembourg, characterized by various soil types such as Cambisols, Luvisols, Arenosols and Calcisols. After collecting more than 300 soil samples of the soil surface, spectral data was related with SOC content using several standard multivariate calibration techniques (Partial Least Square Regression, Penalized-spline Regression, Support Vector Machine). It is shown that calibrations yield reasonably accurate predictions over large areas as long as secondary information (e.g. soil types, agro-pedological regions) are included in the models (Root Mean Square Error of Prediction: ~3 g C kg-1). Such calibration models could be applied to every soil pixel of the hyperspectral image to produce a SOC map of the area. However, predictions have been realized using statistical relationships based on a set of calibration randomly chosen from a set of samples collected during a field campaign, the rest being used for validation purposes. It means that the validation set is not completely independent from the calibration set. As a consequence, a true independent validation (over fields not covered by the calibration/validation sets) would probably give lower accuracies than the ones

  17. Soils of sinkholes: effects of slope aspect and lateral transport of sediments on soil variation

    NASA Astrophysics Data System (ADS)

    Smirnova, Maria; Tsibart, Anna; Abramova, Anna; Koshovskii, Timur; Gennadiev, Alexander

    2015-04-01

    Karst landscapes are highly fragile and particularly vulnerable to subsidence and soil erosion. In karst region there may be hundreds or even thousands of sinkholes and other karst landforms in a small area so that the flat surface is actually absent. The effect of slope aspect on karst landscapes are resulted in different amount of solar radiation and increase of moisture along slopes. In European Russia semiarid landscapes the wind transport of the snow resulted in addition moistening of the soil situated on the eastern slope of depressions. Our research is devoted to the investigation of soil catenas on the slopes of subsidence sinkhole in "Bogdo-Baskuntschak" natural reserve (semiarid landscape). It based on field research of 4 soil catenas situated on the slopes of eastern, northern, western and south exposures. The profile of the sinkhole is an inverted cone (elongated from west to east), slope length varies from 8 to 12 meters, slope gradient - between 40-55% (eastern slope is the shortest and steepest). The short slope length and soil diversity that the sinkholes provided are beneficial for investigation of slope aspect and effect of lateral transport on soil formation. The main feature of sinkhole soil cover is a considerable variety and their high complexity. The lateral transport of sediments resulted in dramatic changes of soil within catenas. Haplic calcisols and arenosols calcaric, situated on the inter-sinkhole flat surface and upper parts of the slopes are substituted by cambisols and leptosols in the middle part of the slopes and colluvic regosols humic in the lower part of the slopes and sinkhole bottom. Soil formation and accumulation of sediments occur simultaneously and lead to the weak soil formation at the middle and lower sections of sinkhole side slopes. The thickness of humus horizon increases from the top to the bottom of sinkhole notably - from 8-12 cm on the upper and middle part of the slopes to 240 cm on the bottom of the sinkhole

  18. Spatial changes in soil organic carbon density and storage of cultivated soils in China from 1980 to 2000

    NASA Astrophysics Data System (ADS)

    Yu, Yanyan; Guo, Zhengtang; Wu, Haibin; Kahmann, Julia A.; Oldfield, Frank

    2009-06-01

    We address the spatial changes in organic carbon density and storage in cultivated soils in China from 1980 to 2000 on the basis of measured data from individual studies and those acquired during the second national soil survey in China. The results show a carbon gain in ˜66% of the cultivated area of China as a whole with the increase in soil organic carbon (SOC) density mostly ranging from 10% to 30%. Soil organic carbon density increased in fluvi-aquic soils (fluvisols, Food and Agriculture Organization (FAO) of the United Nations) in north China, irrigated silting soils (calcaric fluvisols) in northwest China, latosolic red earths (haplic acrisols/alisols), and paddy soils (fluvisols/cambisols) in south China. In contrast, significant decreases are observed in black soils (phaeozems) in northeast China and latosols (haplic acrisols) in southwest China. No significant changes are detected in loessial soils (calcaric regosols) and dark loessial soils (calcisols) in the loess plateau region. The total SOC storage and average density in the upper 20 cm in the late 1990s are estimated to be ˜5.37 Pg C and 2.77 kg/m2, respectively, compared with the values of ˜5.11 Pg C and 2.63 kg/m2 in the early 1980s. This reveals an increase of SOC storage of 0.26 Pg C and suggests an overall carbon sink for cultivated soils in China, which has contributed 2-3% to the global terrestrial ecosystem carbon absorption from 1980 to 2000. Statistical analyses suggest an insignificant contribution to the observed SOC increase from climate change, and we infer that it is mostly attributable to improved agricultural practices. Despite the SOC density increases over 20 years, the SOC density of the cultivated soils in China in the late 1990s is still ˜30% lower compared to their uncultivated counterparts in comparable soil types, suggesting a considerable potential for SOC restoration through improving management practices. Assuming a restoration of ˜50% of the lost SOC in the next 30

  19. Stages of weathering mantle formation from carbonate rocks in the light of rare earth elements (REE) and Sr-Nd-Pb isotopes

    NASA Astrophysics Data System (ADS)

    Hissler, Christophe; Stille, Peter

    2015-04-01

    Weathering mantles are widespread and include lateritic, sandy and kaolinite-rich saprolites and residuals of partially dissolved rocks. These old regolith systems have a complex history of formation and may present a polycyclic evolution due to successive geological and pedogenetic processes that affected the profile. Until now, only few studies highlighted the unusual high content of associated trace elements in weathering mantles originating from carbonate rocks, which have been poorly studied, compared to those developing on magmatic bedrocks. For instance, these enrichments can be up to five times the content of the underlying carbonate rocks. However, these studies also showed that the carbonate bedrock content only partially explains the soil enrichment for all the considered major and trace elements. Up to now, neither soil, nor saprolite formation has to our knowledge been geochemically elucidated. Therefore, the aim of this study was to examine more closely the soil forming dynamics and the relationship of the chemical soil composition to potential sources. REE distribution patterns and Sr-Nd-Pb isotope ratios have been used because they are particularly well suited to identify trace element migration, to recognize origin and mixing processes and, in addition, to decipher possible anthropogenic and/or "natural" atmosphere-derived contributions to the soil. Moreover, leaching experiments have been applied to identify mobile phases in the soil system and to yield information on the stability of trace elements and especially on their behaviour in these Fe-enriched carbonate systems. All these geochemical informations indicate that the cambisol developing on such a typical weathering mantle ("terra fusca") has been formed through weathering of a condensed Bajocian limestone-marl facies. This facies shows compared to average world carbonates important trace element enrichments. Their trace element distribution patterns are similar to those of the soil

  20. Using multi-scale stable isotopes analyses to study the microbial processes of soil organic matter stabilization

    NASA Astrophysics Data System (ADS)

    Hatton, P.; Remusat, L.; Zeller, B.; Bode, S.; Brewer, E.; Boeckx, P. F.; Derrien, D.

    2012-12-01

    Soil microorganisms are increasingly recognized as important drivers for the stabilization of soil organic matter (OM) with soil assemblages, but the way they act remains not fully explored. Here, we used a multi-scale approach to investigate the attachment of microbial products with soil organo-mineral assemblages. A surface acidic Cambisol was amended with 13C15N labeled glycine and leaf fragments prior to sequential density separation of plant debris, aggregates and non-aggregates mineral grains with little OM attached. Labels were tracked using elemental analyzer coupled to isotope ratio mass spectrometry (EA-IRMS), liquid chromatography (LC) coupled to IRMS and nano-scale secondary ions MS (NanoSIMS). After 8h of glycine incubation, the comparison between γ-irradiated and non-sterile soils revealed that more than 90% and 85% of the stabilized glycine-derived 13C and 15N were found in microbial products, with a higher occurrence in aggregates than in plant debris and mineral grains. NanoSIMS images showed that these stabilized microbial products are principally not confined to the microbial cells, but evenly spread at the surface of the mineral-attached OM as extracellular products. After calibration, the comparison of their C/N ratios with the C/N ratios of the corresponding soil particles suggested that the microbial products are stabilized through physico-chemical interactions most likely mediated by the reactivity of the underlying minerals. Unlike NanoSIMS, LC-IRMS analyses allow the tracing of 13C tracers within microbial biomasses using amino sugars as biomarkers. After 3 months of incubation, freshly produced amino sugars deriving from the readily accessible glycine and finely ground leaf fragments clearly peaked in microbial aggregates and plant debris, respectively. Differences in distributions indicated that bacteria and fungi both grow where the resource is, but accumulate in microbial aggregates. These results suggested either a higher