Science.gov

Sample records for sobre suelos cambisoles

  1. Clay fraction mineralogy of a Cambisol in Brazil

    NASA Astrophysics Data System (ADS)

    Anastacio, A. S.; Fabris, J. D.; Stucki, J. W.; Coelho, F. S.; Pinto, I. V.; Viana, J. H. M.

    2005-11-01

    Clay minerals having a 2:1 (tetrahedral:octahedral sheet) structure may be found in strongly weathering soils only if the local pedo-climatic environment prevents them from further weathering to other minerals such as iron oxides. The clay minerals impart important chemical properties to soils, in part by virtue of changes in the redox state of iron in their crystal structures. Knowing the chemical nature of soil clays is a first step in evaluating their potential reactivity with other soil constituents and processes, such as the chemical decomposition of organic substrates to be potentially used in environmental remediation. The purpose of this work was to characterize the iron oxides and iron-bearing clay minerals from a B horizon of a Cambisol developed on tuffite in the State of Minas Gerais, Brazil, using chemical analysis, powder X-ray diffraction, Mössbauer spectroscopy, and thermal analysis. The iron oxides of this NaOH-treated clay-fraction were found to contain mainly maghemite (γFe2O3) and superparamagnetic goethite (αFeOOH). Kaolinite (Al2Si2O5(OH)4), smectite, and minor portions of anatase (TiO2) were identified in the CBD-treated sample.

  2. Microbial responses to southward and northward Cambisol soil transplant.

    PubMed

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

    2015-12-01

    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.

  3. Colloid-bound and dissolved phosphorus species in topsoil water extracts along a grassland transect from Cambisol to Stagnosol

    NASA Astrophysics Data System (ADS)

    Jiang, Xiaoqian; Bol, Roland; Cade-Menun, Barbara J.; Nischwitz, Volker; Willbold, Sabine; Bauke, Sara L.; Vereecken, Harry; Amelung, Wulf; Klumpp, Erwin

    2017-03-01

    Phosphorus (P) species in colloidal and dissolved soil fractions may have different distributions. To understand which P species are potentially involved, we obtained water extracts from the surface soils of a gradient from Cambisol, Stagnic Cambisol to Stagnosol from temperate grassland in Germany. These were filtered to < 450 nm, and divided into three procedurally defined fractions: small-sized colloids (20-450 nm), nano-sized colloids (1-20 nm), and dissolved P (< 1 nm), using asymmetric flow field-flow fractionation (AF4), as well as filtration for solution 31P-nuclear magnetic resonance (NMR) spectroscopy. The total P of soil water extracts increased in the order Cambisol < Stagnic Cambisol < Stagnosol due to increasing contributions from the dissolved P fraction. Associations of C-Fe/Al-PO43-/pyrophosphate were absent in nano-sized (1-20 nm) colloids from the Cambisol but not in the Stagnosol. The 31P-NMR results indicated that this was accompanied by elevated portions of organic P in the order Cambisol > Stagnic Cambisol > Stagnosol. Across all soil types, elevated proportions of inositol hexakisphosphate (IHP) species (e.g., myo-, scyllo- and D-chiro-IHP) were associated with soil mineral particles (i.e., bulk soil and small-sized soil colloids), whereas other orthophosphate monoesters and phosphonates were found in the dissolved P fraction. We conclude that P species composition varies among colloidal and dissolved soil fractions after characterization using advanced techniques, i.e., AF4 and NMR. Furthermore, stagnic properties affect P speciation and availability by potentially releasing dissolved inorganic and ester-bound P forms as well as nano-sized organic matter-Fe/Al-P colloids.

  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. 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).

  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. 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.

  8. 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

  9. Sobre el estado evolutivo de β Pictoris

    NASA Astrophysics Data System (ADS)

    Brunini, A.; Benvenuto, O. G.

    Desde el descubrimiento de fuertes excesos infrarrojos en β Pictoris, esta estrella ha sido muy estudiada y es considerada candidata a poseer un sistema planetario propio. β Pic está rodeada de un disco asimétrico de polvo que se observa de canto y que esta vacío a distancias <= 40 AU. Esto se considera una fuerte evidencia en favor de la presencia de (al menos) un planeta gigante. Recientemente se han observado líneas de material circunestelar que se han interpretado como consecuencia de la caída de objetos cometarios sobre esta estrella. Recientemente se ha utilizado la existencia del disco de polvo para atribuir una edad corta (pre - secuencia principal) a βPic. Sin embargo, la evaporación de estos cometas provee suficiente polvo como para explicar la presencia del disco observado sin necesidad de edades cortas. En este trabajo mostramos que la comparación entre la tasa de impactos cometarios estimada en el Sistema Solar para diferentes etapas de su evolución y los datos observados en β Pic indica edades avanzadas para β Pic. Esta estimación debe tomarse con cautela ya que depende de la estructura de los sistemas planetarios. Además mostramos que, desde el punto de vista de la evolución estelar y con las incertezas presentes en la luminosidad y la temperatura efectiva, existe un continuo de edades posible para β Pic. Sin embargo, empleando los datos provenientes de los flujos cometarios encontramos que una edad prolongada es consistente con ambos tratamientos.

  10. Sobre os sistemas de referência celeste

    NASA Astrophysics Data System (ADS)

    Poppe, P. C. R.; Martin, V. A. F.

    2003-02-01

    Apresentamos neste trabalho, algumas discussões sobre os sistemas de referência utilizados em Astronomia. Claramente, não é possível esgotar todo este assunto num único texto, mas esperamos, contudo, que o presente material possa ser apreciado nos cursos de Introdução à Astronomia, que estão cada vez mais presentes nas atuais propostas curriculares das graduações de Física. As discussões pertinentes às "Bases de Referência Celeste", serão apresentadas em um outro trabalho.

  11. Avisos de salud sobre el PFOA y PFOS en el agua potable

    EPA Pesticide Factsheets

    La EPA estableció avisos de salud sobre el ácido perfluorooctanoico (PFOA) y el sulfonato de perfluorooctano (PFOS) para proporcionar información a los operadores de sistemas de agua potable y funcionarios estatales, tribales y locales sobre los riesgos de

  12. Obtenga más información sobre la etiqueta Safer Choice

    EPA Pesticide Factsheets

    Entérese más acerca del programa EPA Diseño para el medio ambiente, incluyendo información sobre su historia, proyectos anteriores y otros programas de la EPA que están relacionados con este programa.

  13. 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…

  14. 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

  15. 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

  16. 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

  17. 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.

  18. 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

  19. Standard Penetration Test and Relative Density

    DTIC Science & Technology

    1971-02-01

    Se OPSeS Debido a que el agua subterranea granclemente influve la resistencia a suelo, se establecio una relacion empirica entre el nurmero de golpes ...sobre el nivel freatico) con la misma densidad relativa. Asimisnmo, porque se encontr6 que el nu.- mero de golpes depende no solo de la densidad

  20. Human breast milk and adipokines--A potential role for the soluble leptin receptor (sOb-R) in the regulation of infant energy intake and development.

    PubMed

    Zepf, F D; Rao, P; Moore, J; Stewart, R; Ladino, Yuli Martinez; Hartmann, B T

    2016-01-01

    Concentrations of different adipokines in human breast milk are thought to be able to affect energy intake of the infant. Leptin is a hormone synthesized by adipose tissue and the human placenta and favors satiety. The availability of leptin in breast milk is influenced by epithelial cells of the mammary gland that are known to be able to produce leptin, as well as leptin from maternal circulation that is transported to the breast milk, and which can thus in turn reach neonatal blood after absorption. Research so far as mainly focused on leptin concentrations in breast milk. However, evidence suggests that in addition to leptin concentrations levels of the so-called soluble leptin receptor (sOb-R), the main high-affinity binding protein for leptin in humans, are necessary in order to calculate the free leptin index (FLI) and to assess function of the leptin axis. FLI is calculated from the ratio of leptin to the sOb-R, and serves as the main parameter for assessing function of the leptin axis throughout maturation and development. Here we propose that assessing sOb-R levels in addition to leptin concentrations in breast milk could serve as a valuable tool to investigate effects of the leptin axis in breast milk because sOb-R concentrations can impact available leptin levels, and which in turn can have significant implications for infant energy intake and related development.

  1. 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

  2. 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.

  3. Genesis of petroduric and petrocalcic horizons in Latinamerica volcanic soils

    NASA Astrophysics Data System (ADS)

    Quantin, Paul

    2010-05-01

    -arid climate. A complex soil profile of petrocalcic Phaeozem, derived from 4 pyroclastic layers, shows among its successive horizons: in layer 3 the 'upper cangahua' with petrocalcic features and in layer 4 the 'lower cangahua' with hard fragipan properties. The features of the petrocalcic cangahua differ from a Mexican fragipan (Hidalgo & al 1997) by: a hard calcrete, higher alkalinity, stability in water after HCl and NaOH treatment, 2-4% of 'free silica'. The macro and micro-morphology shows: the laminar calcite crust, at the top of cangahua, with alternate micrite-sparite layers; downwards, microcalcite infillings in the voids of a prismatic structure, invading the groundmass by epigenesis of clay sheets, together whith microcrystalline opal. From these data this scenario is inferred: after a former weathering of volcanic glass to form a clayey matrix, as well amorphous silica and microcalcite coatings and infillings, then a second process, perhaps due to drier climate, produced the laminar crust formation, by invasion of microcalcite in the matrix. Conclusion. The petrocalcic horizon in Ecuador was produced by two processes: from a former phase of weathering giving a fragic horizon to a second producing the accumulation of calcite and some opal over and inside the matrix, due to climate change. The petroduric horizon in Mexico, is the product of a very complex soil transformation, from a former clayey Nitisol, through four successive processes: clay eluviation-illuviation, alternate redoximorphy, clay degradation, finally a progressive silicification over and inside the groundmass, probably due to pedoclimate change. References F. Elsass, D. Dubroeucq & M. Thiry. 2000. Clay Minerals, 35, 477-489. C. Hidalgo, P. Quantin & F. Elsass. 1997. Memorias del III Simposio Internacional sobre Suelos volcanicos endurecidos (Quito 1996), p. 65-72. - P. Quantin & C. Zebrowski. 1997. idem, p. 29-47.- J.P. Rossignol & P. Quantin. 1997. idem, p. 73-82.

  4. Un analisis de la influencia de las fricciones de los campos no militares sobre las fricciones del campo militar presentes en la operacion de rescate de rehenes Chavin de Huantar (An Analysis of the Influence that Friction in Non-Military Fields of Action Had Upon Military Friction in the Hostage Rescue Operation Chavin de Huantar)

    DTIC Science & Technology

    2012-05-16

    necesidad inmediata de eliminar la incertidumbre de lo que ocurría al interior de la residencia, por lo que el empleo de micrófonos era vital, a fin...en rarísimas ocasiones se pronuncia sobre hechos políticos y que esta solicitud directa significó una tremenda presión internacional sobre un

  5. Concepciones y concepciones alternativas de estudiantes universitarios/as de biologia y futuros maestros/as de Ciencia de escuela secundaria sobre la teoria de evolucion biologica por seleccion natural

    NASA Astrophysics Data System (ADS)

    Morales Ramos, Egda M.

    La teoria de evolucion biologica (TEB) por seleccion natural es uno de los conceptos unificadores mas importantes del curriculo de Biologia. En Puerto Rico se han hecho pocas investigaciones que abunden sobre las concepciones y concepciones alternativas (CA) que tienen los estudiantes universitarios/as de Biologia y los maestros/as de Ciencia del nivel secundario sobre esta teoria. La politica publica educativa actual establece mediante documentos normativos como los Estandares de contenido y Expectativas de grado del Programa de Ciencias [Puerto Rico Core Standards] la ensenanza de esta teoria. Sin embargo, no se encontraron preguntas sobre la seleccion natural en los ejercicios de practica provistos por el Departamento de Educacion para las pruebas estandarizadas lo cual puede influir para que no se ensene adecuadamente. Las preguntas de investigacion fueron 1. ¿Cuales son las concepciones y concepciones alternativas de estudiantes universitarios/as y de los futuros maestros y maestras de Ciencia sobre la TEB? 2. ¿Cuales conceptos que seleccionan los estudiantes universitarios/as y los futuros maestros y maestras de Ciencia sobre la TEB coinciden con lo aceptado como valido por la comunidad cientifica? y 3. ¿Como comparan las respuestas de la prueba original. v. Entendiendo el cambio biologico que mide concepciones y CA sobre la TEB por seleccion natural, con las de la traducida al idioma espanol? Se utilizo el metodo cuantitativo con un diseno de investigacion transversal por encuesta. La tecnica principal para recopilar los datos fue una prueba con doce items, que formo parte de un instrumento para el cual se recopilaron diversas fuentes de evidencia acerca de su validez. Las muestras estuvieron formadas por 69 estudiantes de Ciencias Naturales y por 16 estudiantes futuros maestros y maestras del nivel secundario de la UPR-RP. Se utilizaron estadisticas descriptivas, analisis de Ji cuadrado y se calcularon los coeficientes alfa de Cronbach y de Spearman

  6. 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

  7. 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.

  8. 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

  9. Conceptos Basicos Sobre el Propano

    SciTech Connect

    2016-08-01

    El propano provee energia a mas de 143.000 vehiculos en los Estados Unidos y 23 millones en todo el mundo. Flotas de todos los Estados Unidos han implementado con exito el uso de vehiculos que funcionan con gas propano, y en la actualidad varios funcionan gracias a este gas, incluyendo autobuses escolares, lanzaderas y autobuses publicos, asi como tambien furgonetas, taxis, vehiculos utilizados por las fuerzas del orden, barredoras de calles y camiones para uso profesional. El propano tambien se utiliza con frecuencia en aplicaciones fuera de la carretera, tales como montacargas, podadoras y equipos de uso profesional y otros equipos agricolas. Las ventajas del propano incluyen la disponibilidad interna, su rendimiento y el hecho de que genera menos emisiones de gases contaminantes que otras alternativas energeticas.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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

  15. [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.

  16. 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.

  17. 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

  18. Investigaciones sobre cascadas electromagnéticas

    NASA Astrophysics Data System (ADS)

    Orellana, M.; Pellizza, L.; Romero, G. E.

    Results from the latest generations of telescopes have revealed a rich sky at high and very high energies with more than a thousand sources at GeV energies and more than a hundred sources at TeV energies. The sources are galactic and extra-galactic natural particle accelerators where emission processes operate efficiently at the gamma-ray domain. The development of pair-photon cascades within the source or along the line of sight may modify the originally emitted spectrum. This effect should be included in our interpretation of the observations in order to progress in the understanding of the physical origin of the emission. Through numerical simulations; we follow the three-dimensional trajectories of such cascades. I here report on the status of our investigations; with focus on the propagation through the background photon fields. FULL TEXT IN SPANISH

  19. 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)

  20. 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…

  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. 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)

  3. Conceptos Basicos Sobre el Gas Natural

    SciTech Connect

    2016-08-01

    El gas natural abastece cerca de 150.000 vehiculos en los Estados Unidos y aproximadamente 22 millones de vehiculos en todo el mundo. Los vehiculos de gas natural (NGV, por sus siglas en ingles) son una buena opcion para las flotas de vehiculos de alto kilometraje, tales como autobuses, taxis, vehiculos de recoleccion de basura, los cuales son alimentados centralmente u operan dentro de un area limitada o a lo largo de una ruta con estaciones de servicio de gas natural. Las ventajas del gas natural como combustible alternativo incluyen su disponibilidad interna, la red de distribucion establecida, un costo relativamente bajo, y los beneficios de las emisiones.

  4. 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.

  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. WSA index as an indicator of soil degradation due to erosion

    NASA Astrophysics Data System (ADS)

    Jaksik, Ondrej; Kodesova, Radka; Schmidtova, Zuzana; Kubis, Adam; Fer, Miroslav; Klement, Ales; Nikodem, Antonin

    2014-05-01

    Knowledge of spatial distribution of soil aggregate stability as an indicator of soil degradation vulnerability is required for many scientific and practical environmental studies. The goal of our study was to assess predisposition of different soil types to change aggregate stability due to erosion. Five agriculture arable lands with different soil types were chosen. The common feature of these sites is relatively large slope and thus soils are impacted by water erosion. The first studied area was in Brumovice. The 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 described at other four locations Vidim, Sedlcany, Zelezna and Hostoun, where the original soil types were Haplic Luvisol on loess and Haplic Cambisol on gneiss, Haplic Cambisol on shales, and Calcaric Cambisol on marlstone, respectively. The regular and semi-regular soil sampling grids were set at all five sites. The basic soil properties were measured and stability of soil aggregates (WSA index) was evaluated. In all cases, the higher aggregates stability was observed in soils, which were not (or only slightly) affected by water erosion and at base slope and the tributary valley (eroded soil particle accumulation). The lowest aggregate stability was measured at the steepest parts. When comparing individual sites, the highest WSA index, e.g. aggregate stability, was found in Sedlcany (Cambisol). Lower WSA indexes were measured on aggregates from Hostoun (Cambisol), Zelezna (Cambisol), Vidim (Luvisol) and the lowest values were obtained in Brumovice (Chernozem). The largest WSA indexes for Cambisols in comparison to Luvisols and Chernozem could be attributed to higher organic matter content and presence of iron oxides. Slightly higher aggregate stability of Luvisols in comparison to Chernozem, could be explained by the positive influence of clay (especially in

  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

    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.

  9. 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

  10. 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.

  11. 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

  12. 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…

  13. Gobierno Federal Contina Investigacin Cientfica Sobre Erupciones en Flint

    EPA Pesticide Factsheets

    Flint, MICH. (24 de marzo, 2016) - Los expertos federales, del estado y del condado de salud y agua entienden que los residentes de Flint están preocupados por la calidad general de su agua-tanto como para beber y para bañarse. En este momento, el an

  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. [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…

  16. Pensamientos Sobre (Thoughts on) Teaching English as a Second Language.

    ERIC Educational Resources Information Center

    Ulibarri, Mari-Luci

    This document presents ideas on various topics in teaching English as a second language. Some of the problems of English orthography and semantics are illustrated. The role of contrastive analysis is mentioned with Spanish-English illustrations. A list of second-language-acquisition principles and techniques is provided, and suggestions for…

  17. Primeros resultados sobre el estudio de oscilaciones no radiales

    NASA Astrophysics Data System (ADS)

    Córsico, A.; Benvenuto, O. G.

    En el Observatorio de La Plata se ha comenzado a elaborar un código de pulsaciones el cual resuelve el problema de las oscilaciones no radiales en el caso adiabático. Dicho código está basado en la técnica de diferencias finitas ampliamente usado en cálculos de estructura y evolución estelar. En este trabajo se presentan los primeros resultados encontrados aplicando el código mencionado al caso de una polítropa de índice n=3. Se presentan los valores de las autofrecuencias y las autofunciones para diferentes modos de pulsación de dicha configuración politrópica. En un futuro próximo, se aplicará este programa al estudio de las pulsaciones no radiales de estrellas enanas blancas.

  18. Sobre prestamos y clasificaciones linguisticas (Regarding Borrowing and Linguistic Classification).

    ERIC Educational Resources Information Center

    Key, Mary Ritchie

    1988-01-01

    This article explores the traditionally accepted etymologies of several lexical borrowings in the indigenous languages of the Americas within the framework of comparative linguistics and linguistic classification. The first section presents a general discussion of the problem of tracing lexical borrowings in this context. The section features a…

  19. 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)

  20. 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…

  1. 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)…

  2. Posible influencia de exoplanetas sobre la actividad estelar

    NASA Astrophysics Data System (ADS)

    Flores, M.; Saffe, C.; Buccino, A. P.; Jaque Arancibia, M.; Mauas, P.

    2016-08-01

    The aim of this work is to analize the possible difference in the levels of activity showed by stars with and without planets. Several authors have suggested that stars with planets, in particular those with hot-Jupiter-like planets, have activity levels greater than those showed for stars of the same spectral class, but without planets. In this contribution we present the analysis of chromospheric activity indexes for 353 objects. To do so, we used high-resolution spectra () of F-, G-, and K-type stars taken with the High Accuracy Radial velocity Planet Searcher spectrograph, installed at the 3.6 m ESO telescope. We do no find a significant difference in the activity indexes of stars with and without planets.

  3. 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…

  4. 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…

  5. 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…

  6. 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;…

  7. 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...

  8. 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.

  9. 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…

  10. 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

  11. Effect of forest and soil type on microbial biomass carbon and respiration

    NASA Astrophysics Data System (ADS)

    Habashi, Hashem

    2016-09-01

    The aim of study was to evaluate the variation of soil microbial biomass carbon (Cmic) and microbial respiration (MR) in three types soil (Chromic Cambisols, Chromic Luvisols and Eutric Leptosols) of mixed beech forest (Beech- Hornbeam and Beech- Maple). Soil was randomly sampled from 0-10 cm layer (plant litter removed), 90 soil samples were taken. Cmic determined by the fumigation-extraction method and MR by closed bottle method. Soil Corg, Ntot and pH were measured. There are significant differences between the soil types concerning the Cmic content and MR. These parameters were highest in Chromic Cambisols following Chromic Luvisols, while the lowest were in Eutric Leptosols. A similar trend of Corg and Ntot was observed in studied soils. Two-way ANOVA indicated that soil type and forest type have significantly effect on the most soil characteristics. Chromic Cambisols shows a productive soil due to have the maximum Cmic, MR, Corg and Ntot. In Cambisols under Beech- Maple forest the Cmic value and soil C/N ratio were higher compared to Beech-Hornbeam (19.5 and 4.1 mg C g-1, and 16.3 and 3.3, respectively). This fact might be indicated that Maple litter had more easy decomposable organic compounds than Hornbeam. According to regression analysis, 89 and 68 percentage of Cmic variability could explain by soil Corg and Ntot respectively.

  12. 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

  13. 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

  14. Design of Airport Pavements for Expansive Soils.

    DTIC Science & Technology

    1981-01-01

    34 .’. . , . Vol. 57:437-444. Nunez, E., and Carrillo, A., (1977) " Suelos Especiales: Colapsibles, Expansivo , Preconsolidados por Desecacion...1975) "Las Arcillas Expansivas: Su Estudio y Trataniento," Laboratorio del Transporte y Mechanica del Suelo , i.,’. ". pp. 3-30. Russam, Kenneth

  15. 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)

  16. 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

  17. ¿Origen dinámico del polvo sobre la superficie de Iapetus?

    NASA Astrophysics Data System (ADS)

    Leiva, A. M.; Briozzo, C. B.

    We implement the three-dimensional Circular Restricted Three Body Prob- lem for low energy particles entering the Saturn­Iapetus system from the recently discovered dust ring. The distribution of impacts with the surface of Iapetus so obtained shows features resembling that of the dark regions observed in this satellite. FULL TEXT IN SPANISH

  18. Informe sobre el proyecto contrastivo hispano-hungaro (Report on the Spanish-Hungarian Contrastive Project)

    ERIC Educational Resources Information Center

    Fulei-Szanto, Andres

    1974-01-01

    A description of a contrastive linguistics project in Hungary aiming to augment linguistic theories in the Spanish language and propound theories for scientific and artistic translation. (Text is in Spanish.) (CK)

  19. 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…

  20. 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…

  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. 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,…

  3. Sobre Algumas Tecnicas de Perturbacao Utilizadas no Problema Ressonante 3/1

    NASA Astrophysics Data System (ADS)

    Balthazar, J. M.; Sagnier, J. L.; Ferraz Mello, S.; Koiller, J.; Yokoyama, T.

    1987-05-01

    ABSTRACT. This work concerns with the study of a particular 3/1 resonant problem for which we have determined formal solutions according to the model belonging to the domain of the Restricted Elliptic Problem of Three Bodies. Key & : ASTEROIDS

  4. 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…

  5. 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.

  6. 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)

  7. 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…

  8. 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…

  9. SOBR: A High-Performance Shared Output Buffered Router for Networks-on-Chip

    NASA Astrophysics Data System (ADS)

    Chen, Yancang; Xie, Lunguo

    This paper presents a single-cycle shared output buffered router for Networks-on-Chip. In output ports, each input port always has an output virtual-channel (VC) which can be exchanged by VC swapper. Its critical path is only 24 logic gates, and it reduces 9.4% area overhead compared with the classical router.

  10. 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…

  11. 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…

  12. 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…

  13. 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)

  14. 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…

  15. 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:…

  16. 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…

  17. Sobre o uso das séries de Puiseux em mecanica celeste

    NASA Astrophysics Data System (ADS)

    Miloni, O. I.

    2003-08-01

    Neste trabalho é apresentada uma demonstração do uso dos diferentes desenvolvimentos em séries para as equações de perturbação em Mecânica Celeste no marco Hamiltoniano. Em trabalhos clássicos como os de Poincaré (Poincaré, 1893) por exemplo, já esta planteado o uso de potências não inteiras no pequeno parâmetro, o que evidencia a não analiticidade das funções quando uma ressonância ocorre. Nestes trabalhos os desenvolvimentos são na raíz quadrada da massa de Júpiter (o pequeno parâmetro). Mais recentemente (Ferraz-Mello, 1985) outros tipos de desenvolvimentos foram aplicados modificando substancialmente as ordens de grandeza e a velocidade de convergência das séries. Com esta abordagem, os desenvolvimentos foram expressados em termos da raíz cúbica do pequeno parâmetro. Neste trabalho apresentamos um enfoque geral, onde os diferentes tipos de desenvolvimentos em séries de Puiseux (Valiron, 1950) são obtidos a partir da aplicação de Teorema de Preparação de Weierstrass (Goursat, 1916) considerando a equação de Hamilton-Jacobi como uma equação algébrica. Os resultados são aplicados ao problema restrito dos três corpos em ressonância de primeira ordem e, dependendo da grandeza da excentricidade do asteróide em relação à de Júpiter, obtemos os diferentes desenvolvimentos, em raíz quadrada ou raíz cúbica da massa de Júpiter.

  18. 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…

  19. 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.

  20. 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)

  1. Perspectiva General sobre la Sordo-Ceguera (Overview on Deaf-Blindness). DB-LINK.

    ERIC Educational Resources Information Center

    Miles, Barbara

    This overview provides basic information on the causes of deaf-blindness and the particular challenges faced by individuals who are deaf-blind. Causes of deaf-blindness include various syndromes, multiple congenital anomalies, prematurity, congenital prenatal dysfunction, and various postnatal causes. Differences between people deaf-blind from…

  2. 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…

  3. 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,…

  4. 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…

  5. 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…

  6. 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…

  7. Sobre las soluciones acotadas del problema instantáneo de dos cuerpos

    NASA Astrophysics Data System (ADS)

    Altavista, C.

    La demostración se basa en el hecho de que las integrales del problema de los N-cuerpos admiten componentes en el campo complejo según las raíces n-ésimas de la unidad. Definida la matriz unitaria correspondiente, la fórmula de Cayley permite transformar la matriz unitaria en una matriz hermitiana. Utilizando como parámetros los cosenos direccionales de un sistema de coordenadas orbitales referidos a un sistema de referencia fijo, puede construirse, utilizando el operador hermitiano antes definido, una forma cuadrática cuyas raíces mínima y máxima definen las cotas respectivas de los movimientos de los mencionados cosenos direccionales.

  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. 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.

  10. Ecotoxicity of benzo[a]pyrene assessed by soil microbial indicators.

    PubMed

    Cheng, Jinjin; Song, Jing; Ding, Changfeng; Li, Xiaogang; Wang, Xingxiang

    2014-09-01

    The ecotoxicity of benzo[a]pyrene (BaP) to soil microorganisms was evaluated using the following microbial indicators: soil microbial biomass, respiration, nitrification, and Shannon index. Two soil types, udic ferrosols and aquic cambisols, were amended with 0 mg/kg, 1 mg/kg, 10 mg/kg, 100 mg/kg, 500 mg/kg, or 1000 mg/kg BaP; incubated at 25 °C; and tested on days 28, 60, and 180. The Shannon index was extremely insensitive to BaP. Microbial biomass and respiration could not be classified as sensitive indicators because of their relatively high 10% effect concentration (EC10) values. Nitrification was the most sensitive indicator in both soils and could be the preferred microbial indicator for testing the ecotoxicity of BaP. Higher toxicity of BaP was exhibited in udic ferrosols than in aquic cambisols, and the ecotoxicity of BaP decreased with incubation time. Extending the 28-d incubation time, which is suggested in the International Organization for Standardization and Organisation for Economic Co-operation and Development guidelines, to 60 d was recommended for future microbial toxicity tests of BaP. On day 28, the EC10 values for microbial biomass, respiration, and nitrification were 71 mg/kg, 43 mg/kg, and 3.4 mg/kg in aquic cambisols and 51 mg/kg, 22 mg/kg, and 1.3 mg/kg in udic ferrosols, respectively. On day 60, these values were 106 mg/kg, 59 mg/kg, and 19 mg/kg in aquic cambisols and 77 mg/kg, 40 mg/kg, and 6.9 mg/kg in udic ferrosols. These values could be used in combination to derive ecotoxicological soil screening levels of BaP.

  11. 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.

  12. Effects of soil type and genotype on cadmium accumulation by rootstalk crops: implications for phytomanagement.

    PubMed

    Ding, Changfeng; Zhang, Taolin; Wang, Xingxiang; Zhou, Fen; Yang, Yiru; Yin, Yunlong

    2014-01-01

    The variations of Cd accumulation in three rootstalk crop species (radish, carrot and potato) were investigated by using twelve cultivars grown in acidic Ferralsols and neutral Cambisols under two Cd treatments (0.3 and 0.6 mg kg(-1)) in a pot experiment The result showed that the total Cd uptake was significantly affected by genotype, soil type and interaction between them, suggesting the importance of selecting proper cultivars for phytoextraction in a given soil type. Among the cultivars tested, potato cultivar Luyin No.1 in Ferralsols and radish cultivar Zhedachang in Cambisols exhibited the highest Cd phytoextraction efficiency in aerial parts (4.45% and 0.59%, respectively) under 0.6 mg kg-1 Cd treatment. Furthermore, the Cd concentrations in their edible parts were below the National Food Hygiene Standard of China (0.1 mg kg(-1), fresh weight). Therefore, phytomanagement of slightly Cd-contaminated soils using rootstalk crops for safe food production combined with long-term phytoextraction was feasible, and potato cultivar Luyin No.1 for Ferralsols and radish cultivar Zhedachang for Cambisols were promising candidates for this approach.

  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. Effect of long-term phosphorus fertilization on soil Se and transfer of soil Se to crops in northern Japan.

    PubMed

    Altansuvd, Javkhlantuya; Nakamaru, Yasuo M; Kasajima, Shinya; Ito, Hirotake; Yoshida, Hozumi

    2014-07-01

    Phosphorus (P) fertilizer can potentially serve as a source for Se accumulation in croplands. Furthermore, it has been reported that the addition of P fertilizer to soil may enhance Se availability. Japanese agricultural soils are typically enriched in P as a result of long-term, excessive P fertilization. Therefore, we conducted a three-year field experiment in order to evaluate the effect of P fertilization on the Se content of soils and crops. Potato, wheat and barley were cultivated with and without P fertilization at two field sites in Hokkaido (northern Japan) with different levels of historical P accumulation. The first field site consisted of an Andosol soil with low available P and the second site, a Cambisol soil with high available P. The three years of continuous P fertilization over the course of the experiment did not result in a significant increase in the Se content of soils or plants. The Se content of soils and plants, however, was higher in soil samples from the Cambisol field site than from the Andosol field site, and total soil Se was significantly correlated with available soil P. Soluble soil Se and the soil-plant transfer factor for Se were not affected by P fertilization. Thus, we concluded that the higher plant Se content at the Cambisol field site was primarily due to the higher levels of accumulated Se in the soil at the site and that historical excess P fertilization typical of agricultural soils in Japan contributes to increased Se uptake by crops.

  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. [A pilot study on the living with a chronic process scale in patients with Parkinson's disease].

    PubMed

    Ambrosio, Leire; Portillo, M Carmen; Rodríguez-Blázquez, Carmen; Carvajal, Ana; Martínez-Martín, Pablo

    2015-11-16

    Introduccion. Para proporcionar un cuidado individualizado e integral a los pacientes con una enfermedad cronica es necesario conocer como conviven con su trastorno. En la actualidad, no existe una escala validada que evalue este aspecto. Objetivo. Presentar el estudio piloto de la version preliminar de la escala de convivencia con un proceso cronico (EC-PC) realizado en pacientes con enfermedad de Parkinson (EP) en España. Pacientes y metodos. Se elaboro una version preliminar de la escala a partir de una revision bibliografica y la participacion de expertos en procesos cronicos y en EP. Quince pacientes, en todos los estadios de la EP, cumplimentaron la version preliminar de la EC-PC (39 items) y un cuestionario sobre la EC-PC. Se analizaron la viabilidad/aceptabilidad y aspectos preliminares de consistencia interna. Resultados. Ningun dominio presento efecto suelo o techo, pero un 43,6% de los items tenia efecto techo. La correlacion item-total corregida fue satisfactoria, excepto en cinco items. La consistencia interna de los cinco dominios resulto satisfactoria, con indices alfa de 0,81-0,92 y coeficientes de homogeneidad de los items de 0,19-0,43. Los pacientes identificaron tres items como ambiguos y dificiles de responder. A partir de estos resultados, se eliminaron 12 items y se elaboro la version final de la EC-PC, cuyo contenido fue considerado satisfactorio tras su evaluacion por profesionales expertos. Conclusiones. La EC-PC, pendiente de validacion, es una escala viable, de interes potencial en el ambito clinico y sociosanitario para evaluar la convivencia con un proceso cronico como la EP.

  17. 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

  18. 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

  19. 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...

  20. 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

  1. 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.

  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. 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.

  4. 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.

    2015-10-23

    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.

  5. 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.…

  6. 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

  7. 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…

  8. 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 and external…

  9. 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…

  10. 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'…

  11. [Sobre la (No) Responsabilidad de la Tecnociencia en los Problemas Ambientales y la Búsqueda de Política].

    PubMed

    Martínez Barrera, Jorge

    2016-01-01

    In this paper I propose to reflect upon modern configuration of technique, i.e., technoscience, and our responsibility towards environmental management. I show that the technological products of our world imply a certain attitude of aggression towards nature, contrasting with the attitude of protection from her, which was peculiar of the pre-technological world. Finally I suggest recovering the classical notion of politics as a possible alternative for controlling techno-scientific imperatives.

  12. 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…

  13. 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…

  14. DISYUNTIVAS EN LAS CONCEPCIONES SOBRE AUTONOMÍA Y BENEFICENCIA QUE AFECTAN LA TERAPÉUTICA DEL INTENTO SUICIDA.

    PubMed

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

    2010-06-01

    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.

  15. 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)

  16. Impacto de la emisión de axiones sobre las propiedades evolutivas y pulsacionales de enanas blancas DB

    NASA Astrophysics Data System (ADS)

    Battich, T.; Althaus, L. G.; Córsico, A. H.

    2016-08-01

    White dwarfs are found to be good laboratories for studying the properties of fundamental particles such as the hypothetical axions. If these particles exist and interact with electrons, they would be emitted from the dense interior of white dwarfs, abandoning these stars without interact again, becoming an important energy sink. This would have a detectable effect on the evolutionary and pulsational properties of white dwarfs. This effect was already studied for DA white dwarfs (white dwarfs with a surface rich in hydrogen), but not for DB white dwarfs (hydrogen-deficient white dwarfs). We studied the general effect of axion emission on the evolution of DB white dwarfs and on the pulsational properties of DBV white dwarfs (pulsating DBs) with the aim of determining the potential of these stars to study the physics of axions. Moreover, we use an estimation of the rate of change of period of the DBV white dwarf PG 1351489 corresponding to the dominant period to derive a new limit on axion mass.

  17. 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

  18. 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...

  19. 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.

  20. Effects of soil type and genotype on lead concentration in rootstalk vegetables and the selection of cultivars for food safety.

    PubMed

    Ding, Changfeng; Zhang, Taolin; Wang, Xingxiang; Zhou, Fen; Yang, Yiru; Yin, Yunlong

    2013-06-15

    Lead (Pb) contamination of soil poses severe health risks to humans through vegetable consumption. The variations of Pb concentration in different parts of rootstalk vegetables (radish, carrot and potato) were investigated by using twelve cultivars grown in acidic Ferralsols and neutral Cambisols under two Pb treatments (125 mg kg(-1) and 250 mg kg(-1) for Ferralsols; 150 mg kg(-1) and 300 mg kg(-1) for Cambisols) in a pot experiment. The Pb concentration in edible parts was higher in Ferralsols under two Pb treatments, with range from 0.28 to 4.14, 0.42-10.66 mg kg(-1) (fresh weight) respectively, and all of them exceeded the food safety standard (0.1 mg kg(-1)) recommended by the Codex Alimentarius Commission of FAO and WHO. The Pb concentration in edible parts was significantly affected by genotype, soil type and the interaction between these two factors. The variation of Pb concentration in different cultivars was partially governed by Pb absorption and the transfer of Pb from aerial to edible part. The results revealed that caution should be paid to the cultivation of rootstalk vegetables in Pb-contaminated Ferralsols without any agronomic management to reduce Pb availability and plant uptake. For Cambisols with slight to moderate Pb contamination, growing potato cultivar Shandong No.1 and Chongqing No.1 was effective in reducing the risk of Pb entering human food chain. The results suggest the possibility of developing cultivar- and soil-specific planting and monitoring guidelines for the cultivation of rootstalk vegetables on slight to moderate Pb-contaminated soils.

  1. 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.

  2. 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.

  3. Heavy metal sorption and desorption capacity of soils containing endogenous contaminants.

    PubMed

    Covelo, Emma Fernández; Vega, Flora Alonso; Andrade, M Luisa

    2007-05-08

    Soils on serpentinites in some regions of northwestern Spain have been the subject of agricultural management practices involving the use of fertilizers and various types of organic waste containing heavy metals. Although such practices have facilitated crop growth, they have also raised the natural contents in heavy metals of the soils. In this work, three ferralic Cambisols and another three mollic Leptosols with high Cr and Ni contents were used to study competitive sorption and desorption of six heavy metals via K(d100), which was employed as a measure of the ability of the soils to adsorb and retain each metal. Lead was found to be the metal sorbed and retained to the greatest extent, and Cd, Ni and Zn those sorbed and retained in the smallest amounts. Although the ferralic Cambisols were found to contain greater amounts of natural heavy metals, they exhibited an increased ability to adsorb and retain the body of metals relative to the mollic Leptosols by effect of their increased contents in clay and Fe, Mn and Al oxides, in addition to their higher ion-exchange capacity. Based on the results, Pb and Cu are strongly bound, and Zn, Cd and Ni weakly bound, to the soils. The ferralic Cambisols exhibited an increased capacity to adsorb and retain Cd, Ni, Zn and--especially--Cr than the mollic Leptosols; the latter, however, proved more effective in adsorbing and retaining Cu and Pb by virtue of their increased organic matter contents. Copper sorption and retention, and Pb retention, were found to be correlated with the content in organic matter and that in vermiculite--which was only present in the mollic Leptosols--in the clay fraction.

  4. 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.

  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. 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

  8. 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

  9. 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.

  10. 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).

  11. 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.

  12. 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

  13. The diversity changes of soil microbial communities stimulated by climate, soil type and vegetation type analyzed via a functional gene array.

    PubMed

    Chen, Fu; Tan, Min; Yang, Yongjun; Ma, Jing; Zhang, Shaoliang; Li, Gang

    2015-11-01

    The aim of this study was to analyze the changes of soil microbial communities stimulated by climate, soil type and vegetation type using a functional gene array. The dataset GSE51592 was obtained from Gene Expression Omnibus, including 54 soil samples. Genetic diversity variation of samples under different sites, soil and vegetation types was examined by calculating the percentage of specific gene number in each sample. Furthermore, gene functional categories and microorganism species in samples under different environmental factors were respectively divided. Gene number in samples with cropping was higher than in samples without cropping. When site, soil type and vegetation type were as the sole variable, respectively, the percentage of specific genes in samples from Yingtan, in phaeozem samples and in samples with cropping was higher. Furthermore, the percentage of gene number in organic remediation for phaeozem and cambisol samples was significant at p < 0.05, comparing with that for acrisol samples. At superkingdom level of microorganisms, for the same category, there was no significant difference (p < 0.05) between the samples. At phylum level, for the categories of Bacteroidetes and Cyanobacteria, the percentage of gene number in cambisol samples was significantly higher (p < 0.05). Conversely, in the category of Proteobacteria, the percentage of gene number in phaeozem and acrisol samples was markedly higher (p < 0.05). Microbial diversity of soil was cooperatively driven by climate, soil type and vegetation type.

  14. 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

  15. Using the dye tracer for visualization of preferential flow in macro and micro-scale

    NASA Astrophysics Data System (ADS)

    Kodesova, Radka; Nemecek, Karel; Kodes, Vit; Fer, Miroslav; Jirku, Veronika; Nikodem, Antonin; Zigova, Anna; Jaksik, Ondrej; Kocarek, Martin

    2010-05-01

    Study is focused on the visualization of the preferential flow in different soil types and their horizons using the dye tracer experiment. Study was performed in the Haplic Luvisol in Hněvčeves and the Haplic Cambisol in Humpolec in the Czech Republic. The 100 (Haplic Luvisol) and 50 (Haplic Cambisol) liters of solute of dye Brilliant Blue FCF (5g/litr) was infiltrated on a 1 x 1 m plot (applying an initial ponding depth of 10 and 5 cm, respectively) immediately after the wheat harvest. On the next day, one half of the plot was sliced horizontally and another half vertically to study the dye distribution within the soil profile to the depth of 100 cm (macro-scale). The 3-D image of the dye distribution was created. In addition, the thin soil sections were made and micromorphological images were used to study a soil aggregate structure and dye distribution in micro-scale. The staining patterns within the vertical and horizontal sections documented very different nature of the preferential flow in different soil types and also within the soil profiles. Images of the Haplic Luvisol showed that while dye tracer was partly regularly transported and only some isolated domains were visible in the surface Ap1 horizon, the preferential flow occurred in the subsurface horizons. The preferential flow in the upper subsurface Ap2 horizon (plow pan) was caused by the gravitational biopores in the very compact matrix structure, which considerably slowed down the dye transport. In the case of deeper horizons (Bt1 and Bt2), the preferential flow occurred due to the gravitational biopores and extensively developed prismatic structure (small and very large aggregates in the Bt1 and Bt2 horizon respectively), which was highly affected by clay coatings. Even better characterization of the preferential flow particularly in these two horizons was obtained, when the same ponding dye infiltration experiment was performed directly on the top of the Bt1 horizon. Images of the Haplic

  16. Investigation of K(o) Testing in Cohesionless Soils

    DTIC Science & Technology

    1975-12-01

    Figure 13. Sketch of the field hydraulic fracture apparatus (courtesy of Sociedad EspaJfola de Mecan- ica del Suelo Cimentaciones2^) outer...Hendron have reported that K is inversely proportional to the angle of internal friction 0 . 29 6 51. In an effort to verify Jaky’s and Hendron’s

  17. 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…

  18. 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…

  19. 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…

  20. Informe sobre el avance del proyecto de determinaciones de V sen i para todas las estrellas B más brillantes que 6.5 mag.

    NASA Astrophysics Data System (ADS)

    Abt, H.; Levato, H.

    Se ha finalizado con la determinación de V sen i para todas las estrellas B más brillantes que 6.5 mag y al norte de -30 grados de declinación. Esta muestra involucra casi 1000 estrellas. Las observaciones fueron realizadas desde KPNO. Mientras tanto, se ha completado desde CASLEO la observación de 350 estrellas B más brillantes que 6.5 mag. al sur de -30 grados. Además de la determinación de la rotación axial se determinan, en los casos posibles, los anchos equivalentes de las líneas 4471 Ådel He I y 4481 Ådel Mg II.

  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. 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)

  3. 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…

  4. Investigación observacional sobre el papel de las estrellas binarias en la ecología de cúmulos estelares

    NASA Astrophysics Data System (ADS)

    González, J. F.; Levato, H.; Grosso, M.

    We present preliminary results of a long-term project devoted to the observational study of the binary star population in open clusters and its connection with the dynamical and evolutionary properties of the clusters. We report the discovery of 17 double-lined spectroscopic binaries, 30 radial velocity variables and about 30 suspected variables. In the 17 clusters of our sample the binary frequency ranges between 20 and 40 %, and reaches typically 60 % if all suspected binaries are included. We study the spatial distribution of the binary stars with respect to the cluster center and we discuss the statistical correlation of the mass-ratio distribution with the cluster age.

  5. Lo Que los Padres y los Maestros Deberian Saber sobre la...Aceleraction (What Parents and Teachers Should Know about Academic Acceleration).

    ERIC Educational Resources Information Center

    Guenther, Alex

    Designed for Spanish-speaking educators and parents, this pamphlet discusses academic acceleration for gifted children. Major types of academic acceleration and their benefits are described. These include: (1) early admission to kindergarten that saves parents of gifted children the expenses of a year of preschool, allows children to be…

  6. 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...

  7. 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…

  8. 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…

  9. 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…

  10. 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…

  11. 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.

  12. 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…

  13. Otra perspectiva sobre lo que los ninos deben estar aprendiendo (Another Look at What Young Children Should Be Learning). ERIC Digest.

    ERIC Educational Resources Information Center

    Katz, Lilian G.

    This Spanish-language ERIC Digest addresses the question of what young children should be learning that will best serve their development and learning in the long term. Two major dimensions of development--normative and dynamic--are explored, and four categories of learning goals are discussed: (1) knowledge; (2) skills; (3) dispositions; and (4)…

  14. 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,…

  15. Nuevos resultados sobre la cinemática global y nuclear de NGC 253: movimientos no circulares y emisión en Br γ

    NASA Astrophysics Data System (ADS)

    Camperi, J. A.; Gunthardt, G. I.; Díaz, R. J.; Agüuero, M. P.; Gimeno, G.; Pessev, P.

    Continuing with previous research (Camperi et al., BAAA, 54, 377, 2011), new heliocentric radial velocity distributions are presented for the nearby galaxy NGC 253, obtained from the ionized hydrogen recombination line Hα. These distributions have been derived from long-slit spectroscopy for various position angles. It is also shown the heliocentric radial velocity distribution corresponding to part of the infrared data (ionized hydrogen recombination line Brγ) observed with the Phoenix spectrograph of the Gemini South Observatory. Sequential mapping with the long slit using this instrument will enable to study in detail the kinematics of the galaxy's core, which is strongly obscured by dust. FULL TEXT IN SPANISH

  16. 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

  17. 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…

  18. 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…

  19. 8 de noviembre de 2006: Mercurio pasea sobre el disco solar (Micro eclipse anular de Sol o el segundo tránsito de Mercurio del siglo XXI)

    NASA Astrophysics Data System (ADS)

    Mallamaci, C. C.

    On Wendsday November 8, 2006, the second transit of Mercury over the Sun of the 21st. Century, took place. In this work we present the principal characteristics of the phenomenon ocurrence, the visibility region and the local circumstances for some locations of Argentina and other countries of the world. Full TEXT IN SPANISH

  20. 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…

  1. 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

  2. Development and Initial Validation of a Questionnaire to Assess the Reading Beliefs of Undergraduate Students: The "Cuestionario de Creencias Sobre la Lectura"

    ERIC Educational Resources Information Center

    Lordán, Eva; Solé, Isabel; Beltran, Francesc S.

    2017-01-01

    The aim of this research was to develop a new questionnaire for exploring the reading beliefs of undergraduate students, because the only currently available instrument has conceptual and methodological limitations. The paper describes the process of developing the instrument and presents a range of psychometric data obtained from a sample of 558…

  3. 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.

  4. 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…

  5. 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…

  6. Sobre la posible existencia de un bulbo o núcleo de población II en la Nube Mayor de Magallanes

    NASA Astrophysics Data System (ADS)

    Clariá, J. J.; Dutra, D. M.; Bica, E.; Piatti, A. E.

    Based on recent results obtained with the Hubble Space Telescope, we present a census of genuine globular clusters in the Large Magellanic Cloud (LMC) and we examine their spatial distribution. Spectroscopic observations carried out at Complejo Astronómico El Leoncito (CASLEO, Argentina) allow us to add two new clusters (NGC 1928 and NGC 1939) to the list of genuine LMC globular clusters. We present evidence that old clusters projected on the LMC bar region may constitute a population II core, probably reminiscent of an ancient bulge, which together with a central disc could have evolved into the observed LMC bar by SMC and/or Galaxy interactions. A detailed discussion was given in MNRAS 305, 373 (1999).

  7. 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…

  8. 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.

  9. 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.

  10. 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…

  11. 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,…

  12. 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…

  13. Estudio Sobre Portadores Cronicos de Salmonellas en Manipuladores de Alimentos de la Ciudad de Iquitos (Study of Chronic Salmonella Carriers in Food Handlers in the City of Iquitos)

    DTIC Science & Technology

    1990-01-01

    manipuladores de alimentos en estudio. 779 (77.90%) fueron del sexo femcnino y 221 (22.10%) del sexo masculino. siendo el mayor porcentaje mujeres (234 - 30.04...papel de ios portadlores cr6- Woos en 460 mujeres dadas de alt. del hospital de Chile, encontrandose 34 porta- dores o sea 7.4 % excediindose las...4 sujetos 3.6 % portadores cr6nicos de Salmoncilas. 1S0 En Argentina 1974, se inves:,16 la frecuencia de Saiimoncilas en 146 manipulado- res de

  14. 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…

  15. 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…

  16. 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.

  17. 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.

  18. 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…

  19. 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.…

  20. 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

  1. Monitoring heavy metal concentrations in leachates from a forest soil subjected to repeated applications of sewage sludge.

    PubMed

    Egiarte, G; Pinto, M; Ruíz-Romera, E; Camps Arbestain, M

    2008-12-01

    The aim of the study was to establish whether the repeated application of sewage sludge to an acid forest soil (Dystric Cambisol) would lead to short-term groundwater contamination. Sludge was applied at four loading rates (0, 2.4, 17 and 60 Mg ha(-1)) in two consecutive years and leachates were analysed. Heavy metal inputs to soils at the lowest dose were below EC regulations but, at higher doses, limits for Zn, Cd, Cr and Ni were exceeded. Repeated application of sludge at 60 Mg ha(-1) resulted in significantly (P<0.05) higher concentrations of Zn, Cd, Cr and Ni in the leachates than with other treatments. The drinking water standards for Cd and Ni were surpassed in all treatments. Control plots were contaminated by groundwater flow despite the existence of buffer zones between plots. This complicated interpretation of the results, highlighting the importance of careful design of this type of experiment.

  2. Changes in the agrochemical properties of major arable soils in the south of the Far East of Russia under the impact of their long-term agricultural use

    NASA Astrophysics Data System (ADS)

    Burdukovskii, M. L.; Golov, V. I.; Kovshik, I. G.

    2016-10-01

    Agrochemical properties of meadow-brown (Gleyic Cambisols (Clayic, Aric)) and meadow-chernozemic (Luvic Gleyic Chernic Phaeozems (Loamic, Aric, Pachic)) soils under the impact of long-term application of mineral and organic fertilizers were studied. The investigations were performed at the agrochemical experimental stations of the Primorskii region and Amur oblast founded in 1941 and 1962, respectively. It was shown that the long-term crop cultivation without fertilizers or with great rates of mineral fertilizers and lime resulted in the soil dehumification, a rise in the soil acidity, and a decrease of the content of exchangeable bases. These processes were slowed down by the application of organic fertilizers. Agrochemical parameters of meadow-chernozemic and floodplain meadow (Fluvic Phaeozems (Loamic, Aric, Oxyaquic)) soils of Amur oblast (Russia) and the Heilongjiang border province (China) were compared.

  3. 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.

  4. 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

  5. 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

  6. Seasonal variability of soil aggregate stability

    NASA Astrophysics Data System (ADS)

    Rohoskova, M.; Kodesova, R.; Jirku, V.; Zigova, A.; Kozak, J.

    2009-04-01

    Seasonal variability of soil properties measured in surface horizons of three soil types (Haplic Luvisol, Greyic Phaeozem, Haplic Cambisol) was studied in years 2007 and 2008. Undisturbed and disturbed soil samples were taken every month to evaluate field water content, bulk density, porosity, ration of gravitational and capillary pores, pHKCl and pHH2O, organic matter content and its quality, aggregate stability using WSA index. In addition, micromorphological features of soil aggregates were studied in thin soil sections that were made from undisturbed large soil aggregates. Results showed that soil aggregate stability depended on stage of the root zone development, soil management and climatic conditions. Larger aggregate stabilities and also larger ranges of measure values were obtained in the year 2007 then those measured in 2008. This was probably caused by lower precipitations and consequently lower soil water contents observed in 2007 than those measured in 2008. The highest aggregate stability was measured at the end of April in the years 2007 and 2008 in Haplic Luvisol and Greyic Phaeozem, and at the end of June in the year 2007 and at the beginning of June in 2008 in Haplic Cambisol. In all cases aggregate stability increased during the root growth and then gradually decreased due to summer rainfall events. Aggregate stability reflected aggregate structure and soil pore system development, which was documented on micromorphological images and evaluated using the ration of gravitational and capillary pores measured on the undisturbed sol samples. Acknowledgement: Authors acknowledge the financial support of the Grant Agency of the Czech Republic grant No. 526/08/0434, and the Ministry of Education, Youth and Sports grant No. MSM 6046070901.

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    Biota-soil interaction in natural ecosystems is an area of considerable research. Our hypothesis is that individual trees play a significant role through biomechanical and biochemical disturbances in soil formation in temperate forest resulting in 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 only SIGEO site in continental Europe - in time and space we compared extensive dendrochronological, soil and pit-mound microtopography data on an area of 42.01 ha collected in 2008-2012. The datasets differ in terms of information complexity and length of memory. Tree cores contain complex information about disturbance history of the past 350 years, footprints of the specific tree uprooting disturbance can persist 1700 years, and soils representing extensive composite phenotype have been developing for at least the entire postglacial period (10 500 years). On average, 6.18-13.41% of the canopy was disturbed on individual soil units 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 characteristics of treethrow dynamics as well as frequencies of stronger releases in core series significantly differed also along a gradient of terrestrial soil weathering and leaching (Haplic Cambisols - Dystric Cambisols - Entic Podzols - Albic Podzols). Results suggest the existence of several disturbance regimes within the forest controlling fine-scale pedodiversity.

  8. 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

  9. 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.

  10. Variation in Soil Respiration across Soil and Vegetation Types in an Alpine Valley

    PubMed Central

    Rubin, Aurélie

    2016-01-01

    Background and Aims Soils of mountain regions and their associated plant communities are highly diverse over short spatial scales due to the heterogeneity of geological substrates and highly dynamic geomorphic processes. The consequences of this heterogeneity for biogeochemical transfers, however, remain poorly documented. The objective of this study was to quantify the variability of soil-surface carbon dioxide efflux, known as soil respiration (Rs), across soil and vegetation types in an Alpine valley. To this aim, we measured Rs rates during the peak and late growing season (July-October) in 48 plots located in pastoral areas of a small valley of the Swiss Alps. Findings Four herbaceous vegetation types were identified, three corresponding to different stages of primary succession (Petasition paradoxi in pioneer conditions, Seslerion in more advanced stages and Poion alpinae replacing the climactic forests), as well as one (Rumicion alpinae) corresponding to eutrophic grasslands in intensively grazed areas. Soils were developed on calcareous alluvial and colluvial fan deposits and were classified into six types including three Fluvisols grades and three Cambisols grades. Plant and soil types had a high level of co-occurrence. The strongest predictor of Rs was soil temperature, yet we detected additional explanatory power of sampling month, showing that temporal variation was not entirely reducible to variations in temperature. Vegetation and soil types were also major determinants of Rs. During the warmest month (August), Rs rates varied by over a factor three between soil and vegetation types, ranging from 2.5 μmol m-2 s-1 in pioneer environments (Petasition on Very Young Fluvisols) to 8.5 μmol m-2 s-1 in differentiated soils supporting nitrophilous species (Rumicion on Calcaric Cambisols). Conclusions Overall, this study provides quantitative estimates of spatial and temporal variability in Rs in the mountain environment, and demonstrates that estimations of

  11. Travel times in the vadose zone: Variability in space and time

    NASA Astrophysics Data System (ADS)

    Sprenger, Matthias; Seeger, Stefan; Blume, Theresa; Weiler, Markus

    2016-08-01

    Water travel times reflect hydrological processes, yet we know little about how travel times in the unsaturated zone vary with time. Using the soil physical model HYDRUS-1D, we derived time variable travel time distributions for 35 study sites within the Attert catchment in Luxembourg. While all sites experience similar climatic forcing, they differ with regard to soil types (16 Cambisols, 12 Arenosols, and 7 Stagnosols) and the vegetation cover (29 forest and 6 grassland). We estimated site specific water flow and transport parameters by fitting the model simulations to observed soil moisture time series and depth profiles of pore water stable isotopes. With the calibrated model, we tracked the water parcels introduced with each rainfall event over a period of several years. Our results show that the median travel time of water from the soil surface to depths down to 200 cm is mainly driven by the subsequent rainfall amounts. The median time until precipitation is taken up by roots is governed by the seasonality of evapotranspiration rates. The ratio between the amount of water that leaves the soil profile by on the one hand and evaporation and transpiration on the other hand also shows an annual cycle. This time variable response due to climatic forcing is furthermore visible in the multimodal nature of the site specific master transit time distribution representing the flow-averaged probability density for rainwater to become recharge. The spatial variability of travel times is mainly driven by soil texture and structure, with significant longer travel times for the clayey Stagnosols than for the loamy to sandy Cambisols and Arenosols.

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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

  18. Soil erosion after forest fires in the Valencia region

    NASA Astrophysics Data System (ADS)

    González-Pelayo, Óscar; Keizer, Jan Jacob; Cerdà, Artemi

    2014-05-01

    31, 219-236. Boix-Fayos, C., Martínez-Mena, M., Calvo-Cases, A., Castillo, V.M., Albadalejo, J. 2005. Concise review of interrill erosion studies in SE Spain (Alicante and Murcia): erosion rates and progress of knowledge from the 1980s. Land Degradation and Developement 16, 517-528. Calvo-Cases, A., Boix-Fayós, C., Imeson, A.C. 2003. Runoff generation, sediment movement and soil water behaviour on calcareous (limestone) slopes of some Mediterranean environments in southeast Spain. Geomorphology 50, 269-291. Campo, J., Andreu, V., Gimeno-García, E., González-Pelayo, O., Rubio, J.L. 2008. Aggregation of under canopy and bare soils in a Mediterranean environment affected by different fire intensities. Catena 74 (3), 212-218. Campo, J., Andreu, V., Gimeno-García, E., González, O., Rubio, J.L. 2006. Occurrence of soil erosion after repeated experimental fires in a Mediterranean environment. Geomorphology 82, 376-387. Cerdà A. 2001. Erosión hídrica del suelo en el territorio Valenciano. El estado de la cuestión a través de la revisión bibliográfica. Geoforma Ediciones: Logronho. A. 2001. Cerdá, A, Mataix-Solera, J. 2009. Incendios forestales en España. Ecosistemas terrestres y suelos. En: Cerdá y Mataix-Solera (Eds.), Efectos de los incendios forestales sobre los suelos en España. Universidad de Valencia, 2009. Cerdà, A. 1998a. Postfire dynamics of erosional processes under mediterranean climatic conditions. Zeitschrift für Geomorphologie, 42 (3) 373-398. Cerdà, A. 1998b. Changes in overland flow and infiltration after a rangeland fire in a Mediterranean scrubland. Hydrological Processes, 12, 1031-1042. Cerdà, A., Doerr, S.H. 2008. The effect of ash and needle cover on surface runoff and erosion in the immediate post-fire period. Catena, 74 , 256- 263. doi:10.1016/S0341-8162(02)00027-9 Cerdà, A., Imeson, A.C., Calvo, A. 1995. Fire and aspect induced differences on the erodibility and hydrology of soils at La Costera, Valencia, Southeast Spain. Catena

  19. Breast Cancer Epidemiology in Puerto Rico

    DTIC Science & Technology

    2012-06-01

    residencial, el uso de vitaminas y medicinas , informacion sobre Ia menstruaci6n y los hijos que ha tenido, al igual que algunas preguntas sobre diagnostico y...historial residencial, uso de vitaminas y medicinas , informacion sobre Ia menstruacion y los embarazos y alguna informacion sobre el diagnostico y

  20. 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…

  1. 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…

  2. 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 District in…

  3. 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...

  4. Todo Alumno: Un Manual de Recursos de PEER sobre Educacion Basada en Normas y Alumnos con Discapacidades (Every Single Student: A PEER Resource Manual on Standards-Based Education and Students with Disabilities).

    ERIC Educational Resources Information Center

    Landau, Julia K., Ed.; Romano, Carolyn A., Ed.; Vohs, Janet R., Ed.

    This manual in Spanish covers thirteen different topics relevant to the education of students with disabilities in the era of educational reform and standards-based education. Sections include: (1) "Raising Standards of Learning: Standards-Based Education and Students with Disabilities" (Janet R. Vohs, Julia K. Landau, and Carolyn…

  5. Relatorio Final Sobre o Ensino Bilingue: Resultados da Avaliacao Externa da Experiencia de Escolarizacao Bilingue em Mocambique (PEBIMO) (Final Report on Bilingual Education: Results of External Evaluation of an Experiment in Bilingual Education in Mozambique).

    ERIC Educational Resources Information Center

    Benson, Carolyn J.

    The PEBIMO project was designed to determine whether bilingual education could improve the quality of primary education in Mozambique, recognizing that Portuguese is not the native language of the majority of Mozambican students. The project began in 1992 with 8 cohorts of first grade in 2 provinces; during this investigation, students were in…

  6. 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 study…

  7. 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…

  8. 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…

  9. 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…

  10. Ten Facts Every Parent Should Know about the No Child Left Behind Act = Diez datos que cada padre debe saber sobre La Ley. Que Ningun Nino Se Quede Atras.

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC.

    The No Child Left Behind Act (NCLB) is President George W. Bush's education reform law passed by Republicans and Democrats in Congress. This flier, in both English and Spanish, details 10 facts concerning NCLB to inform parents as to the goals of the Act and how they will affect their child's school. The flier highlights how the Act: (1) gives…

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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…

  19. 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…

  20. 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…

  1. 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.…

  2. [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.

  3. 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…

  4. 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…

  5. 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…

  6. 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.

  7. 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…

  8. 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…

  9. 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…

  10. 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…

  11. 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…

  12. 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

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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.…

  19. [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.

  20. 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 respostas escritas mais comuns da nossa pesquisa indicaram que os alunos precisam de mais orientação e melhor preparação para escrever ensaios bem sucedidos. Como os alunos consideraram difíceis os aspectos conceituais dos ensaios, no futuro iremos fornecer atividades relevantes antes dos ensaios para ajudar os alunos a escrevê-los com sucesso.

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. Soil wind erosion in ecological olive trees in the Tabernas desert (southeastern Spain): a wind tunnel experiment

    NASA Astrophysics Data System (ADS)

    Asensio, Carlos; Lozano, Francisco Javier; Gallardo, Pedro; Giménez, Antonio

    2016-08-01

    Wind erosion is a key component of the soil degradation processes. The purpose of this study is to find out the influence of material loss from wind on soil properties for different soil types and changes in soil properties in olive groves when they are tilled. The study area is located in the north of the Tabernas Desert, in the province of Almería, southeastern Spain. It is one of the driest areas in Europe, with a semiarid thermo-Mediterranean type of climate. We used a new wind tunnel model over three different soil types (olive-cropped Calcisol, Cambisol and Luvisol) and studied micro-plot losses and deposits detected by an integrated laser scanner. We also studied the image processing possibilities for examining the particles attached to collector plates located at the end of the tunnel to determine their characteristics and whether they were applicable to the setup. Samples collected in the traps at the end of the tunnel were analyzed. We paid special attention to the influence of organic carbon, carbonate and clay contents because of their special impact on soil crusting and the wind-erodible fraction. A principal components analysis (PCA) was carried out to find any relations on generated dust properties and the intensity and behavior of those relationships. Component 1 separated data with high N and OC contents from samples high in fine silt, CO3= and available K content. Component 2 separated data with high coarse silt and clay contents from data with high fine sand content. Component 3 was an indicator of available P2O5 content. Analysis of variance (ANOVA) was carried out to analyze the effect of soil type and sampling height on different properties of trapped dust. Calculations based on tunnel data showed overestimation of erosion in soil types and calculation of the fraction of soil erodible by wind done by other authors for Spanish soils. As the highest loss was found in Cambisols, mainly due to the effect on soil crusting and the wind

  12. 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

  13. [Protocol for neurophysiological studies of the pelvic floor to appraise anorectal dysfunction in patients with multiple sclerosis].

    PubMed

    Álvarez-Guerrico, Ion; Royo, Inmaculada; Andreu, Montserrat; Roquer-González, Jaume; Munteis, Elvira

    2016-03-01

    Introduccion. Los pacientes con esclerosis multiple (EM) frecuentemente desarrollan disfuncion anorrectal. Las estructuras neuromusculares del suelo pelvico y los mecanismos de control voluntario de la defecacion pueden afectarse por las lesiones parcheadas de la EM o secundarias a la discapacidad del paciente. La implicacion multifactorial limita la comprension de la fisiopatologia de la disfuncion anorrectal en la EM. Tests neurofisiologicos especificos valoran la funcionalidad de los elementos del sistema nervioso central y periferico implicados en las disfunciones anorrectales. Objetivo. Proponer un protocolo diagnostico de estudios neurofisiologicos estandarizados del suelo pelvico para caracterizar la fisiopatologia de la disfuncion anorrectal en los pacientes con EM. Pacientes y metodos. Se realizaron estudios de electromiografia de esfinter anal externo, potenciales evocados somatosensoriales desde el nervio pudendo interno, registro de reflejos sacros anales y neurografia del nervio pudendo a 16 pacientes con EM definida y criterios de estreñimiento o incontinencia fecal. Resultados. Las caracteristicas clinicas y neurofisiologicas fueron heterogeneas. Nueve pacientes presentaron estreñimiento; dos, incontinencia fecal aislada; y cinco, combinacion de ambos. La abolicion o el retraso de la latencia de los potenciales evocados somatosensoriales fue el hallazgo mas frecuente (n = 12), seguido de la deteccion de contraccion paradojica (n = 11) y de reclutamiento deficitario (n = 8) en la electromiografia de esfinter anal externo. Conclusiones. La correcta interpretacion de cada test neurofisiologico disponible y la correlacion de los hallazgos en conjunto permiten comprender la fisiopatologia de la disfuncion anorrectal. La protocolizacion de estudios neurofisiologicos del suelo pelvico permite ajustar el diagnostico al identificar la lesion nerviosa, central o periferica, determinante de disfuncion anorrectal en los pacientes con EM.

  14. Characterization and validation of a Portuguese natural reference soil to be used as substrate for ecotoxicological purposes.

    PubMed

    Caetano, A L; Gonçalves, F; Sousa, J P; Cachada, A; Pereira, E; Duarte, A C; Ferreira da Silva, E; Pereira, R

    2012-03-01

    This study describes the first attempt to validate a Portuguese natural soil (PTRS1) to be used as reference soil for ecotoxicological purposes, aimed to both: (i) obtain ecotoxicological data for the derivation of Soil Screening Values (SSVs) with regional relevance, acting as a substrate to be spiked with ranges of concentrations of the chemicals under evaluation and (ii) act as control and as substrate for the dilution of contaminated soils in ecotoxicological assays performed to evaluate the ecotoxicity of contaminated soils, in tier 2 of risk assessment frameworks, applied to contaminated lands. The PTRS1 is a cambisol from a granitic area integrated in the Central Iberian Zone. After chemical characterization of the soil in terms of pseudo-total metals, PAHs, PCBs and pesticide contents, it was possible to perceive that some metals (Ba, Be, Co, Cr and V) surpass the Dutch Target Values (Dtvs) corrected for the percentage of organic matter and clay of the PTRS1. Nevertheless, these metals displayed total concentrations below the background total concentrations described for Portuguese soils in general. The same was observed for aldrin, endosulfan I, endosulfan II, heptachlor epoxide, and heptachlor; however the Dtvs corrected become negligible. The performance of invertebrate and plant species, commonly used in standard ecotoxicological assays, was not compromised by both soil properties and soil metal contents. The results obtained suggest that the PTRS1 can be used as a natural reference soil in ecotoxicological assays carried out under the scope of ecological risk assessment.

  15. The effects of worms, clay and biochar on CO2 emissions during production and soil application of co-composts

    NASA Astrophysics Data System (ADS)

    Barthod, Justine; Rumpel, Cornélia; Paradelo, Remigio; Dignac, Marie-France

    2016-12-01

    In this study we evaluated CO2 emissions during composting of green wastes with clay and/or biochar in the presence and absence of worms (species of the genus Eisenia), as well as the effect of those amendments on carbon mineralization after application to soil. We added two different doses of clay, biochar or their mixture to pre-composted green wastes and monitored carbon mineralization over 21 days in the absence or presence of worms. The resulting co-composts and vermicomposts were then added to a loamy Cambisol and the CO2 emissions were monitored over 30 days in a laboratory incubation. Our results indicated that the addition of clay or clay/biochar mixture reduced carbon mineralization during co-composting without worms by up to 44 %. In the presence of worms, CO2 emissions during composting increased for all treatments except for the low clay dose. The effect of the amendments on carbon mineralization after addition to soil was small in the short term. Overall, composts increased OM mineralization, whereas vermicomposts had no effect. The presence of biochar reduced OM mineralization in soil with respect to compost and vermicompost without additives, whereas clay reduced mineralization only in the composts. Our study indicates a significant role of the conditions of composting on mineralization in soil. Therefore, the production of a low CO2 emission amendment requires optimization of feedstocks, co-composting agents and worm species.

  16. Effect of application of phosphate and organic manure-based fertilizers on arsenic transformation in soil columns.

    PubMed

    Sisr, Ludek; Mihaljevic, Martin; Ettler, Vojtech; Strnad, Ladislav; Sebek, Ondrej

    2007-12-01

    The mobility of arsenic in Cambisol under the influence of added barnyard manure and application of a phosphate solution to the soil was described on the basis of column experiments. A soil sample containing 126 mg/kg total As and 3.72 mg/kg specifically-sorbed As was extracted using demineralized water (DIW) or a 28 micromol/l phosphate solution in a column containing untreated soil and in a column with added barnyard fertilizer. The pH, Eh, alkalinity, main components, including DOC, and selected trace elements (Al, Mn, Pb, Cu, Zn, Cd, Cr, Co, Ni, Ba and As) were determined in the extracts. Hydrodynamic tests of the flow and transport of the substances in the columns were carried out. The addition of barnyard manure was manifested in elevated concentrations of the main inorganic components, DOC and Al and a decrease in the Eh value and Mn concentration. Application of a phosphate solution was manifested in a decrease in the NO(3) and SO(4) concentrations, probably as a result of the effect of increased biological fixation. The As concentration in extracts varied from 8.8 to 15.5 microg/l and was not dependent on the composition of the extracting solution or the addition of barnyard fertilizer.

  17. Characteristics of a paleosol and its implication for the Critical Zone development, Rocky Mountain Front Range of Colorado, USA.

    NASA Astrophysics Data System (ADS)

    Leopold, M.; Völkl, J.; Dethier, D.; Huber, J.; Steffens, M.

    2012-04-01

    Activity and stability phases as well as geomorphic processes within the Critical Zone are well known. Erosion and deposition of sediments represent activity; soils represent geomorphic stability phases. We present data from a 4 m deep sediment section that was dated by luminescence techniques. Upslope erosion and resulting sedimentation started in the late Pleistocene around 18 ka until 12 ka. Environmental conditions at the study site then changed, which led to the formation of a well-developed soil. Radiocarbon dating of the organic matter yielded ages between 8552 - 8995 cal. BP. From roughly 6.2 - 5.4 ka another activity phase accompanied by according sediment deposition buried the soil and a new soil, a Cambisol, was formed at the surface. The buried soil is a strongly developed Luvisol. The black colors in the upper part of the buried soil are not the result of pedogenic accumulation of normal organic matter within an A-horizon. Nuclear magnetic resonance spectroscopy (NMR) clearly documents the high amount of aromatic components (charcoal), which is responsible for the dark color. It is corroborated by charcoal pieces seen in then sections. This indicates severe burning events at the site and the smaller charcoal dust (black carbon) was transported in deeper parts of the profile during the process of clay translocation. We present further NMR data from overlaying horizons that may indicate actual lessivation of clay and black carbon in this kind of environment.

  18. 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

  19. Short-term effects on soil properties and wheat production from secondary paper sludge application on two Mediterranean agricultural soils.

    PubMed

    Rato Nunes, J; Cabral, F; López-Piñeiro, A

    2008-07-01

    This study was conducted under greenhouse conditions to evaluate the potential use of SPS as a fertilizer, amendment and/or liming agent for wheat (Triticum aestivum L.). Two representative Mediterranean agricultural soils, a Cambic Arenosol (cmAR) and a Cromic Cambisol (crCM) were used. Treatments included four sludge rates ranging from 0 to 40 g kg(-1) (equivalent of 0, 38, 88 and 120 Mg ha(-1)). A significant increment in soil pH, organic carbon, N total, available P and exchangeable K were observed in both soils. Sludge application significantly increased N and decreased Zn, Mn and Cu concentrations in wheat. Wheat grain yields were reduced by 33% and 37% when 120 Mg SPS ha(-1) was applied to cmAR and crCM soils, respectively, due apparently to unavailability of Mg. However, straw yields, with much lower Mg requirements, increased significantly with SPS rates. Secondary pulp mill sludge seems to be a potential source of organic matter, N, P, K and a potential soil amendment liming agent for acid soils, when appropriate supplemental fertilizer was provided. For grain crops grown in these soils, addition of Mg is required for proper nutrient balance.

  20. Electrothermal atomic absorption spectrometric determination of vanadium in extracts of soil and sewage sludge certified reference materials after fractionation by means of the Communities Bureau of Reference modified sequential extraction procedure

    NASA Astrophysics Data System (ADS)

    Žemberyová, M.; Jankovič, R.; Hagarová, I.; Kuss, H.-M.

    2007-05-01

    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, cambisol) and sewage sludge of different composition originating from a municipal water treatment plant in order to assess potential mobility and the distribution of vanadium in the resulting fractions. Analysis of the extracts was carried out by electrothermal atomic absorption spectrometry with Zeeman background correction using transversely heated graphite atomizers. Extracts showed significant matrix interferences which were overcome by the standard addition technique. The original soil and sludge certified reference materials (CRMs) and the extraction residue from the sequential extraction were decomposed by a mixture of HNO 3-HClO 4-HF in an open system. The content of V determined after decomposition of the samples was in very good agreement with the certified total values. The accuracy of the sequential extraction procedure was checked by comparing the sum of the vanadium contents in the three fractions and in the extraction residue with the certified total content of V. The amounts of vanadium leached were in good correlation with the certified total contents of V in the CRMs of soils and sewage sludge. In the soils examined, vanadium was present almost entirely in the mineral lattice, while in the sewage sludge samples 9-14% was found in the oxidizable and almost 25% in the reducible fractions. The recovery ranged from 93-106% and the precision (RSD) was below 10%.

  1. 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

  2. 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.

  3. 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).

  4. 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

  5. Coatings in cryoaridic soils and other records of landscape and climate changes in the Ak-Khol Lake basin (Tyva)

    NASA Astrophysics Data System (ADS)

    Bronnikova, M. A.; Konoplianikova, Yu. V.; Agatova, A. R.; Zazovskaya, E. P.; Lebedeva, M. P.; Turova, I. V.; Nepop, R. K.; Shorkunov, I. G.; Cherkinsky, A. E.

    2017-02-01

    An assemblage of coatings in cryoaridic soils (Skeletic Cambisols Protocalcic) of southwestern Tyva is considered as a key block of soil memory, which is an intrasoil archive of landscape and climate changes in regional geosystems in the Holocene. The results of hierarchical macro-, meso-, and micromorphological studies of a large assemblage of coatings and the data on the X-ray microanalysis of coatings and composition of stable carbon and oxygen isotopes, as well as on radiocarbon dating of coatings are presented. The synthesis of the results made it possible to reconstruct the main evolutionary phases of cryoaridic soils in the Holocene and landscape and climate changes that induced their alteration. The following climatogenic evolutionary phases of pedogenesis were distinguished: (1) formation of microsparite-micritic dense silica-containing coatings due to short-term fluctuations of the shallow alkaline bicarbonate groundwater level in the semiarid-arid climate; (2) formation of sparitic dense coatings under the slow accumulation of carbonates from low-mineralized bicarbonate water at the higher lake level as compared to the present one in the less arid conditions; (3) the eluvial-illuvial formation of micritic loose coatings under stable automorphic semiarid conditions; (4) formation of Fe-humus coatings in cool humid climate (Al-Fe-humus phase of pedogenesis); (5) the recommencement of the eluvial-illuvial formation of micritic loose coatings under aridization of the last thousand years of the Holocene.

  6. 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.

  7. 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

  8. Total and available soil trace element concentrations in two Mediterranean agricultural systems treated with municipal waste compost or conventional mineral fertilizers.

    PubMed

    Baldantoni, Daniela; Leone, Anna; Iovieno, Paola; Morra, Luigi; Zaccardelli, Massimo; Alfani, Anna

    2010-08-01

    The temporal dynamics of some trace elements in two different types of Mediterranean soils were studied in order to evaluate the possible long-term contamination following compost amendments. Total and available (DTPA-extractable) concentrations of Cd, Cu, Pb and Zn were determined. The study was carried out on two agricultural soils in Campania region (southern Italy), a Sandy Loam Calcaric Cambisol (SG) and a Clay Gleyc Luvisol (CO), during 3 years of organic amendment with compost. The compost, produced from the organic fraction of municipal solid waste and urban yard trimmings, in accordance with the Italian law for agricultural use, was applied at annually rates of 15, 30, and 45 t ha(-1) (on dry weight basis). Wide variations in total and available Cd, Cu, Pb and Zn concentrations were observed over time, but appeared to be in many cases unrelated to the treatments, occurring also in control plots. After 3 years of compost application the amended SG soil showed the highest and significant increase in total Cd and Zn concentrations; in addition, the available Cd, Pb and Zn concentrations increased in accordance with the compost rates. The CO soil, characterized by a higher clay content, lower organic matter content and lower cation exchange capacity, exhibited a lower increase in available metal fractions. Our findings show that compost amendment affects more the available than the total metal concentrations in the two types of soils studied and thus it is important into legislation that metal "bioavailability" may be considered in defining threshold metal values.

  9. Influence of plant root exudates on the mobility of fuel volatile compounds in contaminated soils.

    PubMed

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

    2014-01-01

    Vegetation and its associated microorganisms play an important role in the behaviour of soil contaminants. One of the most important elements is root exudation, since it can affect the mobility, and therefore, the bioavailability of soil contaminants. In this study, we evaluated the influence of root exudates on the mobility of fuel derived compounds in contaminated soils. Samples of humic acid, montmorillonite, and an A horizon from an alumi-umbric Cambisol were contaminated with volatile contaminants present in fuel: oxygenates (MTBE and ETBE) and monoaromatic compounds (benzene, toluene, ethylbenzene and xylene). Natural root exudates obtained from Holcus lanatus and Cytisus striatus and ten artificial exudates (components frequently found in natural exudates) were added to the samples, individually and as a mixture, to evaluate their effects on contaminant mobility. Fuel compounds were analyzed by headspace-gas chromatography-mass spectrometry. In general, the addition of natural and artificial exudates increased the mobility of all contaminants in humic acid. In A horizon and montmorillonite, natural or artificial exudates (as a mixture) decreased the contaminant mobility. However, artificial exudates individually had different effects: carboxylic components increased and phenolic components decreased the contaminant mobility. These results established a base for developing and improving phytoremediation processes of fuel-contaminated soils.

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

    PubMed

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

    2015-09-23

    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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Metal oxides, clay minerals and charcoal determine the composition of microbial communities in matured artificial soils and their response to phenanthrene.

    PubMed

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

    2013-10-01

    Microbial communities in soil reside in a highly heterogeneous habitat where diverse mineral surfaces, complex organic matter and microorganisms interact with each other. This study aimed to elucidate the long-term effect of the soil mineral composition and charcoal on the microbial community composition established in matured artificial soils and their response to phenanthrene. One year after adding sterile manure to different artificial soils and inoculating microorganisms from a Cambisol, the matured soils were spiked with phenanthrene or not and incubated for another 70 days. 16S rRNA gene and internal transcribed spacer fragments amplified from total community DNA were analyzed by denaturing gradient gel electrophoresis. Metal oxides and clay minerals and to a lesser extent charcoal influenced the microbial community composition. Changes in the bacterial community composition in response to phenanthrene differed depending on the mineral composition and presence of charcoal, while no shifts in the fungal community composition were observed. The abundance of ring-hydroxylating dioxygenase genes was increased in phenanthrene-spiked soils except for charcoal-containing soils. Here we show that the formation of biogeochemical interfaces in soil is an ongoing process and that different properties present in artificial soils influenced the bacterial response to the phenanthrene spike.

  17. 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.

  18. Influence of mineral and organic components on copper, lead, and zinc sorption by acid soils.

    PubMed

    Vega, Flora A; Covelo, Emma F; Vázquez, Juan J; Andrade, Luisa

    2007-12-01

    Sorption isotherms were constructed for the sorption of Cu, Pb and Zn by the surface horizons of three soils [a Humic Cambisol (G1), a Haplic Podzol (G2) and an Umbric Gleysol (G3)] and by fractions obtained by sequential removal of organic matter and oxides. All were of L-type except the H-type isotherms recorded for sorption of lead by whole G2, and all were fitted well by the Langmuir model, with determination coefficients > 0.91. Langmuir equation parameter beta correlated well (r(2) = 0.985) with experimentally maximum sorption capacity. For all soils, metal sorption capacities decreased in the order Zn > Cu > Pb. Sorption by organic matter was one of the main contributions to total sorption. Sorption by oxides was generally most substantial in G1, which had the largest total oxides content, while the sorption of lead by G3 was attributable to its high Mn oxides content. The clayey residue contributed significantly to sorption of zinc by G1, and G3 (due to their respective vermiculite and gibbsite contents) and to sorption of copper by G1 due to its vermiculite content.

  19. Morphogenetic features of soils in the Cat Tien National Park, southern Vietnam

    NASA Astrophysics Data System (ADS)

    Khokhlova, O. S.; Myakshina, T. N.; Kuznetsov, A. N.; Gubin, S. V.

    2017-02-01

    Morphogenetic features of soils on the selected plots in the Cat Tien National Park in southern Vietnam have been studied with the use of a set of morphological, analytical, and instrumental methods. The lithological factor and topographic position play the leading role in the development of the particular genetic soil features. The soils can be subdivided into four groups according to these factors. The soils developing from volcanic deposits with a predominance of tephra can be classified as thin clayey brown tropical soils (Dystric Skeletic Rhodic Cambisols (Clayic)), and the soils developed from less weathered colluvial derivatives of basalts with some admixture of tephra can be classified as dark-humus clayey tropical soils (Skeletic Greyzemic Umbrisols (Clayic)). Very poor soils developed from the eluvium of argillites are classified as thin weakly developed clayey tropical soils (Dystric Regosols (Clayic)). The soils forming from the alluvial sediments of different textures are classified as alluvial loamy sandy soils (Dystric Fluvisols (Arenic, Drainic)) and as alluvial clay loamy soils (Eutric Fluvisols (Episiltic, Endoclayic)).

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. [Analysis of food service and opinion of its users in a Catalan prison].

    PubMed

    Sáiz Izquierdo, María Elena; Fornons Fontdevila, David; Medina Luque, F Xavier; Aguilar Martínez, Alicia

    2014-07-01

    INTRODUCCIÓN: Los estudios sobre restauración colectiva se encuentran viviendo un cierto auge en España. Sin embargo, se dispone de muy poca información sobre cómo se organiza este servicio en las instituciones penitenciarias, y mucho menos aún sobre cómo es percibido por sus usuarios.

  5. Teaching Kids About Using Medicine Safely

    MedlinePlus

    ... videos for consumers on YouTube Enseñando a los Niños Sobre el Uso de Medicamentos Seguramente Vea este ... de la FDA sobre la enseñanza de los niños mayores sobre el uso de medicinas seguramente. back ...

  6. 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

  7. 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

  8. 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

  9. 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

  10. ...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…

  11. 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)…

  12. 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.

  13. 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…

  14. 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…

  15. 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.

  16. 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…

  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. 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…

  19. 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…

  20. 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…

  1. 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…

  2. 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)

  3. 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…

  4. 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…

  5. "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…

  6. 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…

  7. [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.

  8. 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)…

  9. 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…

  10. 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…

  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. 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…

  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. 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…

  15. 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…

  16. 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…

  17. 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…

  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…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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…

  4. 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…

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  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. 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.

  15. 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.

  16. 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.

  17. Use of plant growth promoting bacterial strains to improve Cytisus striatus and Lupinus luteus development for potential application in phytoremediation.

    PubMed

    Balseiro-Romero, María; Gkorezis, Panagiotis; Kidd, Petra S; Van Hamme, Jonathan; Weyens, Nele; Monterroso, Carmen; Vangronsveld, Jaco

    2017-03-01

    Plant growth promoting (PGP) bacterial strains possess different mechanisms to improve plant development under common environmental stresses, and are therefore often used as inoculants in soil phytoremediation processes. The aims of the present work were to study the effects of a collection of plant growth promoting bacterial strains on plant development, antioxidant enzyme activities and nutritional status of Cytisus striatus and/or Lupinus luteus plants a) growing in perlite under non-stress conditions and b) growing in diesel-contaminated soil. For this, two greenhouse experiments were designed. Firstly, C. striatus and L. luteus plants were grown from seeds in perlite, and periodically inoculated with 6 PGP strains, either individually or in pairs. Secondly, L. luteus seedlings were grown in soil samples of the A and B horizons of a Cambisol contaminated with 1.25% (w/w) of diesel and inoculated with best PGP inoculant selected from the first experiment. The results indicated that the PGP strains tested in perlite significantly improved plant growth. Combination treatments provoked better growth of L. luteus than the respective individual strains, while individual inoculation treatments were more effective for C. striatus. L. luteus growth in diesel-contaminated soil was significantly improved in the presence of PGP strains, presenting a 2-fold or higher increase in plant biomass. Inoculants did not provoke significant changes in plant nutritional status, with the exception of a subset of siderophore-producing and P-solubilising bacterial strains that resulted in significantly modification of Fe or P concentrations in leaf tissues. Inoculants did not cause significant changes in enzyme activities in perlite experiments, however they significantly reduced oxidative stress in contaminated soils suggesting an improvement in plant tolerance to diesel. Some strains were applied to non-host plants, indicating a non-specific performance of their plant growth promotion

  18. Partitioning CO2 effluxes from an Atlantic pine forest soil between endogenous soil organic matter and recently incorporated 13C-enriched plant material.

    PubMed

    Fernandez, Irene; Cabaneiro, Ana; González-Prieto, Serafín J

    2006-04-15

    Soil CO2 effluxes from recently added 13C-labeled phytomass versus endogenous soil organic matter (SOM) were studied in an acid soil from Atlantic pine forests (NW Spain). After several cultures to incorporate fresh 13C-enriched Lolium perenne to a Humic Cambisol with predominance of humus--Al over humus--Fe complexes, potential soil C mineralization was determined by laboratory aerobic incubation (84 days). Isotopic 13C analyses of SOM fractions were assessed to know in which organic compartments the 13C was preferentially incorporated. Although in the 13C-labeled soil the C mineralization coefficient totalized less than 3% of soil C, the 13C mineralization coefficient exceeded 14%, indicating a greater lability of the newly incorporated organic matter. Organic compounds coming from added phytomass showed a higher lability and contributed considerably to the total soil CO2 effluxes (52% of total soil CO2 evolved during the first decomposition stages and 27% at the end), even though added-C comprised less than 4% of total soil C. Good determination coefficients, when values of CO2--C released were fitted to a first-order double exponential kinetic model, support the existence of two C pools of different lability. Kinetic parameters obtained with this model indicated that phytomass addition augmented the biodegradability of the labile pool (instantaneous mineralization rate k increased from 0.07 d(-1) to 0.12 d(-1)) but diminished that of the recalcitrant pool (instantaneous mineralization rate h decreased from 2.7 x 10(-4) d(-1) to 1.6 x 10(-4) d(-1)). Consequently, the differentiation between both SOM pools increased, showing the importance of SOM quality on CO2 emissions from this kind of soil to the atmosphere.

  19. Microbially-mediated transformation and mobilization of soil Fe-organic associations

    NASA Astrophysics Data System (ADS)

    Poggenburg, Christine; Mikutta, Robert; Schippers, Axel; Dohrmann, Reiner; Kaufhold, Stephan; Guggenberger, Georg

    2014-05-01

    Soil organic matter (OM) has been proposed to be stabilized in the long term via sorption to iron((oxy)hydr)oxides under aerobic conditions. However, in an anaerobic environment, Fe-organic associations may be subject to microbial reduction and mobilization, which counteract the suggested stabilizing effect of Fe compounds. Desorption of OM can result in its microbial decomposition causing the emission of greenhouse gases (CO2, CH4, N2O) or release of associated contaminants into the soil solution and groundwater. While the reductive dissolution of pure iron((oxy)hydr)oxides by dissimilatory FeIII reducing bacteria is well established, little is known about the influence of natural OM on microbially mediated mobilization of Fe-organic associations. Therefore, this study aims to elucidate the effect of adsorbed OM on microbial FeIII reduction of Fe-organic associations with regard to (i) the composition of OM, (ii) the carbon loading, and (iii) surface coverage and/or pore blockage by adsorbed OM. Mineral-organic associations with varying carbon contents were synthesized using several iron((oxy)hydr)oxides (Goethite, Lepidocrocite, Ferrihydrite, Hematite, Magnetite) and OM of different origin (dissolved OM extracted from the Oa horizon of a Podzol and Oi horizon of a Cambisol, extracellular polymeric substance extracted from Bacillus subtilis). Incubation experiments under anaerobic conditions were conducted for 16 days using two different strains of dissimilatory FeIII reducing bacteria (Shewanella putrefaciens, Geobacter metallireducens). At five sampling points in time the solution phase was analyzed for pH, Fetotal, and FeII. The initial mineral-organic associations and post-incubation phase were characterized by N2 gas adsorption, FTIR, XRD, and XPS. The results indicate that the composition of OM and carbon loading significantly influence the rate and extend of microbial reduction of Fe-organic associations depending on the type of microbial strain and iron

  20. 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.

  1. 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.

  2. 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

  3. 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.

  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.

  5. 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.

  6. 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.

  7. 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.

  8. Sequestration of manure-applied sulfadiazine residues in soils.

    PubMed

    Förster, M; Laabs, V; Lamshöft, M; Groeneweg, J; Zühlke, S; Spiteller, M; Krauss, M; Kaupenjohann, M; Amelung, W

    2009-03-15

    It is not the total but the (bio)accessible concentration of veterinary medicines that determines their toxicity in the environment. We elucidate the changes in (bio)accessibility of manure-applied sulfadiazine (SDZ) with increasing contact time in soil. Fattening pigs were medicated with 14C-labeled SDZ, and the contaminated manure (fresh and aged) was amended to 2 soil types (Cambisol, Luvisol) and incubated for 218 days at 10 degrees C in the dark. Antibiotic residues of different bioaccessibility were approached by sequential extractions with 0.01 M CaCl2 (CaCl2 fraction), methanol (MeOH fraction), and finally acetonitrile/water (residual fraction, microwave extraction at 150 degrees C). In each fraction, total radioactivity, SDZ, and its major metabolites were quantified. The results showed that both SDZ and,to a lesser extent 4-hydroxysulfadiazine (4-OH-SDZ) were rapidly reformed from N-acetylsulfadiazine (N-ac-SDZ) during the first 2-4 weeks after fresh manure application, i.e., the N-acetylated metabolite does not sequester in soil to a significant extent Yet, the water and methanol extractable SDZ and 4-OH-SDZ also dissipated rapidly (DT50 = 6.0-32 days) for the fresh manure treatment with similar rate constants for both soil types. In the residual fractions, however, the concentrations of both compounds increased with time. We conclude that the residual fraction comprises the sequestered pool of SDZ and its hydroxylated metabolite. There they are entrapped and may persist in soil for several years. Including the residual fraction into fate studies thus yields dissipation half-lives of SDZ which exceed those previously reported for sulfonamides by a factor of about 100.

  9. 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).

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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.

  15. A conceptual model describing the fate of sulfadiazine and its metabolites observed in manure-amended soils.

    PubMed

    Zarfl, Christiane; Klasmeier, Jörg; Matthies, Michael

    2009-10-01

    Sulfadiazine (SDZ) belongs to the chemical class of sulfonamides, one of the most important groups of antibiotics applied in animal husbandry in Europe. These antibiotics end up in the soil after manure from treated animals is applied as fertilizer. They can inhibit soil microbial functions and enhance the spread of resistance genes among soil microorganisms. In order to assess the exposure of soil microorganisms to SDZ, a conceptual kinetic model for the prediction of temporally resolved antibiotic concentrations in soil was developed. The model includes transformation reactions, reversible sequestration and the formation of non-extractable residues (NER) from SDZ and its main metabolites N(4)-acetyl-sulfadiazine (N-ac-SDZ) and 4-hydroxy-sulfadiazine (OH-SDZ). The optimum model structure and rate constants of SDZ kinetics and its metabolites were determined by fitting different model alternatives to sequential extraction data of a manure-amended Cambisol soil. N-ac-SDZ is degraded to SDZ with a half-life of 4d, whereas OH-SDZ is not. Though, based on the available data, the hydroxylation of SDZ seems to be negligible, it is still included in the model structure since this process has been observed in recent studies. Sequestration into a residual fraction has similar kinetics for SDZ, N-ac-SDZ and OH-SDZ and is one order of magnitude faster than the reverse translocation. The irreversible formation of NER is restricted to SDZ and OH-SDZ. The model shows good agreement when applied to extraction data measured independently for a Luvisol soil. The combination of sequential extraction data and the conceptual kinetic model enables us to gain further insight into the long-term fate and exposure of sulfonamides in soil.

  16. Simultaneous sorption of four ionizable pharmaceuticals in different horizons of three soil types.

    PubMed

    Kočárek, Martin; Kodešová, Radka; Vondráčková, Lenka; Golovko, Oksana; Fér, Miroslav; Klement, Aleš; Nikodem, Antonín; Jakšík, Ondřej; Grabic, Roman

    2016-11-01

    Soils may be contaminated by human or veterinary pharmaceuticals. Their behaviour in soil environment is largely controlled by sorption of different compounds in a soil solution onto soil constituents. Here we studied the sorption affinities of 4 pharmaceuticals (atenolol, trimethoprim, carbamazepine and sulfamethoxazole) applied in solute mixtures to soils taken from different horizons of 3 soil types (Greyic Phaeozem on loess, Haplic Luvisol on loess and Haplic Cambisol on gneiss). In the case of the carbamazepine (neutral form) and sulfamethoxazole (partly negatively charged and neutral), sorption affinity of compounds decreased with soil depth, i.e. decreased with soil organic matter content. On the other hand, in the case of atenolol (positively charged) and trimethoprim (partly positively charged and neutral) compound sorption affinity was not depth dependent. Compound sorption affinities in the four-solute systems were compared with those experimentally assessed in topsoils, and were estimated using the pedotransfer rules proposed in our previous study for single-solute systems. While sorption affinities of trimethoprim and carbamazepine in topsoils decreased slightly, sorption affinity of sulfamethoxazole increased. Decreases in sorption of the two compounds could be attributed to their competition between each other and competition with atenolol. Differences between carbamazepine and atenolol behaviour in the one- and four-solute systems could also be explained by the slightly different soil properties in this and our previous study. A great increase of sulfamethoxazole sorption in the Greyic Phaeozem and Haplic Luvisol was observed, which was attributed to elimination of repulsion between negatively charged molecules and particle surfaces due to cation sorption (atenolol and trimethoprim) on soil particles. Thus, our results proved not only an antagonistic but also a synergic affect of differently charged organic molecules on their sorption to soil

  17. 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.

  18. A long-term field experiment of soil transplantation demonstrating the role of contemporary geographic separation in shaping soil microbial community structure.

    PubMed

    Sun, Bo; Wang, Feng; Jiang, Yuji; Li, Yun; Dong, Zhixin; Li, Zhongpei; Zhang, Xue-Xian

    2014-04-01

    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.

  19. 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

  20. Soil organic carbon stocks assessment in Mediterranean natural areas: a comparison of entire soil profiles and soil control sections.

    PubMed

    Parras-Alcántara, L; Lozano-García, B; Brevik, E C; Cerdá, A

    2015-05-15

    Soil organic carbon (SOC) is an important part of the global carbon (C) cycle. In addition, SOC is a soil property subject to changes and highly variable in space and time. Over time, some researches have analyzed entire soil profile (ESP) by pedogenetic horizons and other researches have analyzed soil control sections (SCS) to different thickness. However, very few studies compare both methods (ESP versus SCS). This research sought to analyze the SOC stock (SOCS) variability using both methods (ESP and SCS) in The Despeñaperros Natural Park, a nature reserve that consists of a 76.8 km(2) forested area in southern Spain. Thirty-four sampling points were selected in the study zone. Each sampling point was analyzed in two different ways, as ESP (by horizons) and as SCS with different depth increments (0-25, 25-50, 50-75 and 75-100 cm). The major goal of this research was to study the SOCS variability at regional scale. The soils investigated in this study included Phaeozems, Cambisols, Regosols and Leptosols. Total SOCS in the Despeñaperros Natural Park was over 28.2% greater when SCS were used compared to ESP, ranging from 0.8144 Tg C (10,604.2 Mg km(-2)) to 0.6353 Tg C (8272.1 Mg km(-2)) respectively (1 Tg = 10(12) g). However, when the topsoil (surface horizon and superficial section control) was analyzed, this difference increased to 59.8% in SCS compared to ESP. The comparison between ESP and SCS showed the effect of mixing pedogenetic horizons when depth increments were analyzed. This indicates an overestimate of T-SOCS when sampling by SCS.

  1. 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.

  2. 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.

  3. 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.

  4. Utilization of W/Mg(NO 3) 2 modifiers for the direct determination of As and Sb in soils, sewage sludge and sediments by solid sampling electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Török, Peter; Žemberyová, Mária

    2010-04-01

    A simple method has been developed for the determination of arsenic and antimony in environmental samples by solid sampling electrothermal atomic absorption spectrometry, which was validated using certified reference materials of soils (S-VM — Soil Eutric Cambisol; S-MS — Soil Orthic Luvisols; S-SP — Soil Rendzina), sewage sludge (WT-L; WT-M) and sediments (NIES2; GBW07906). The analytical procedure combines solid sampling with utilization of a matrix modifier admixture containing 5 µg of W and 5 µg of Mg. The tungsten in the admixture serves to stabilize the solid matrix during atomisation, which results in dramatically reduced non-specific absorption compared with the conventional palladium modifier. Magnesium was efficient in reducing the accumulation of the matrix residue on the platform. An alternative resonance line of 197.2 nm for arsenic and 206.8 nm for Sb was used in order to eliminate the spectral interferences caused by aluminum compounds, and silicon and iron compounds, respectively. Under optimized experimental conditions, the effective in situ analyte/matrix separation was achieved so that the use of aqueous standards for calibration became possible. With the modifier, a 3 SD detection limit of 0.5 µg g -1 As and 0.1 µg g -1 Sb and 10 SD quantification limit of 1.7 µg g -1As and 0.3 µg g -1 Sb and a characteristic mass of 65 pg As and 53 pg Sb were obtained. For all the matrices under scrutiny, a good agreement with certified values was achieved with RSD values less than 10%.

  5. Monitoring soil volume wetness in heterogeneous soils by electrical resistivity. A field-based pedotransfer function

    NASA Astrophysics Data System (ADS)

    Brillante, Luca; Bois, Benjamin; Mathieu, Olivier; Bichet, Vincent; Michot, Didier; Lévêque, Jean

    2014-08-01

    Modern irrigation techniques require accurate, rapid, cost-effective, spatial measurement of soil moisture. Electrical Resistivity Tomography (ERT) meets most of these requirements, but needs to be calibrated for each use because it is very sensitive to differences in soil characteristics. In this study, a pedotransfer function approach is used to remove the need for site-specific calibration, allowing ERT to be used directly to measure soil moisture. The study site was a hillslope vineyard, where eight calcaric-cambisol soil profiles were identified. From 2012 to 2013, 23 000 soil volume wetness measurements were acquired by Time Domain Reflectometry, and over 100 000 electrical resistivity data were collected in 160 ERT acquisitions. To better understand the ERT signal, soil texture, gravel content, cation exchange capacity, CaCO3, pH, organic carbon and total nitrogen were analysed in 64 soil samples from the study site. The sensitivity of ERT to differences in soil characteristics makes it difficult to establish a unique model linking electrical resistivity and soil moisture in heterogeneous soils. This study presents two possible solutions to overcome this problem, which are differentiated by the availability of data on soil characteristics. When these data are not available, it is possible to fit a number of different models for each homogeneous soil layer, but a site-specific calibration is necessary at least once. Conversely, when soil characteristics are available, they can be integrated into the model to build a pedotransfer function. A unique, accurate model is obtained in this way for all samples. In soils with similar characteristics to those observed, the function can be used directly to measure soil moisture by ERT. Developing pedotransfer functions such the one presented here could greatly improve, simplify and develop the use of electrical resistivity to measure soil moisture.

  6. 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.

  7. Pesticide volatilization from soil: lysimeter measurements versus predictions of European registration models.

    PubMed

    Wolters, André; Linnemann, Volker; Herbst, Michael; Klein, Michael; Schäffer, Andreas; Vereecken, Harry

    2003-01-01

    A comparison was drawn between model predictions and experimentally determined volatilization rates to evaluate the volatilization approaches of European registration models. Volatilization rates of pesticides (14C-labeled parathion-methyl, fenpropimorph, and terbuthylazine and nonlabeled chlorpyrifos) were determined in a wind-tunnel experiment after simultaneous soil surface application on Gleyic Cambisol. Both continuous air sampling, which quantifies volatile losses of 14C-organic compounds and 14CO2 separately, and the detection of soil residues allow for a mass balance of radioactivity of the 14C-labeled pesticides. Recoveries were found to be > 94% of the applied radioactivity. The following descending order of cumulative volatilization was observed: chlorpyrifos > parathion-methyl > terbuthylazine > fenpropimorph. Due to its high air-water partitioning coefficient, nonlabeled chlorpyrifos was found to have the highest cumulative volatilization (44.4%) over the course of the experiment. Volatilization flux rates were measured up to 993 microg m(-2) h(-1) during the first hours after application. Parameterization of the Pesticide Emission Assessment at Regional and Local Scales (PEARL) model and the Pesticide Leaching Model (PELMO) was performed to mirror the experimental boundary conditions. In general, model predictions deviated markedly from measured volatilization rates and showed limitations of current volatilization models, such as the uppermost compartment thickness, making an enormous influence on predicted volatilization losses. Experimental findings revealed soil moisture to be an important factor influencing volatilization from soil, yet its influence was not reflected by the model calculations. Future versions of PEARL and PELMO ought to include improved descriptions of aerodynamic resistances and soil moisture dependent soil-air partitioning coefficients.

  8. N use efficiencies and N2O emissions in two contrasting, biochar amended soils under winter wheat—cover crop—sorghum rotation

    NASA Astrophysics Data System (ADS)

    Hüppi, Roman; Neftel, Albrecht; Lehmann, Moritz F.; Krauss, Maike; Six, Johan; Leifeld, Jens

    2016-08-01

    Biochar, a carbon-rich, porous pyrolysis product of organic residues, is evaluated as an option to tackle major problems of the global food system. Applied to soil, biochar can sequester carbon and have beneficial effects on nitrogen (N) cycling, thereby enhancing crop yields and reducing nitrous oxide (N2O) emissions. There is little understanding of the underlying mechanisms, but many experiments indicated increased yields and manifold changes in N transformation, suggesting an increase in N use efficiency. Biochar’s effects can be positive in extensively managed tropical agriculture, however less is known about its use in temperate soils with intensive fertilisation. We tested the effect of slow pyrolysis wood chip biochar on N use efficiency, crop yields and N2O emissions in a lysimeter system with two soil types (sandy loamy Cambisol and silty loamy Luvisol) in a winter wheat—cover crop—sorghum rotation. 15N-labelled ammonium nitrate fertiliser (170 kg N ha-1 in 3 doses, 10% 15N) was applied to the first crop to monitor its fate in three ecosystem components (plants, soil, leachate). Green rye was sown as cover crop to keep the first year’s fertiliser N for the second year’s sorghum crop (fertilised with 110 kg N ha-1 in two doses and natural abundance 15N). We observed no effects of biochar on N fertiliser use efficiency, yield or N uptake for any crop. Biochar reduced leaching by 43 ± 19% but only towards the end of the experiment with leaching losses being generally low. For both soils N2O emissions were reduced by 15 ± 4% with biochar compared to the control treatments. Our results indicate that application of the chosen biochar induces environmental benefits in terms of N2O emission and N leaching but does not substantially affect the overall N cycle and hence crop performance in the analyzed temperate crop rotation.

  9. 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.

  10. Thermal treatment and leaching of biochar alleviates plant growth inhibition from mobile organic compounds.

    PubMed

    Gale, Nigel V; 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

  11. The use of Mediterranean shrub to flight against the land degradation. The rainfall partitioning fluxes

    NASA Astrophysics Data System (ADS)

    García-Estringana, Pablo; Nieves Alonso-Blazquez, M.; Alegre, Jesús; Cerdà, Artemi

    2014-05-01

    abandonment. Acknowledgements TThe research projects 07 M/0077/1998, 07 M/0023/2000 and RTA01-078-C2- 2, GL2008-02879/BTE, LEDDRA243857 and RECARE FP7 project 603498 supported this research. References: Belmonte Serrato, F., Romero Díaz, A. 1998. A simple technique for measuring rainfall interception by small shrub: "interception flow collection box. Hydrological Processes 12, 471-481. Cerdà, A. 1998. Relationship between climate and soil hydrological and erosional characteristics along climatic gradients in Mediterranean limestone areas. Geomorphology, 25, 123-134. Cerdà, A., Doerr, S.H. 2007. Soil wettability, runoff and erodibility of major dry-Mediterranean land use types on calcareous soils. Hydrological Processes, 21, 2325-2336. doi: 10.1016/j.catena.2008.03.010. Cerdà, A., Lasanta, A. 2005. Long-term erosional responses after fire in the Central Spanish Pyrenees: 1. Water and sediment yield. Catena, 60, 59-80. Garcia-Estringana, P. 2011. Efectos de diferentes tipos de vegetación mediterránea sobre la hidrología y la pérdida de suelo. Tesis Doctoral, Universidad de Alcalá, Facultad de Ciencias, pp. 170. Garcia-Estringana, P., Alonso-Blázquez, N., Marques, M.J., Bienes, R., Alegre, J. 2010. Direct and indirect effects of Mediterranean vegetation on runoff and soil loss. European Journal of Soil Science 61, 174-185. Izzo, M., Araujo, N., Aucelli, P. P. C., Maratea, A., and Sánchez, A. 2013. Land sensitivity to Desertification in the Dominican Republic: an adaptation of the ESA methodology. Land Degradation & Development, 24: 486- 498. DOI 10.1002/ldr.2241 Lasanta, A., Cerdà, A. 2005. Long-term erosional responses after fire in the Central Spanish Pyrenees: 2. Solute release. Catena, 60, 80-101 Miao, C. Y., Yang, L., Chen, X. H., Gao, Y. 2012. The vegetation cover dynamics (1982-2006) in different erosion regions of the Yellow River Basin, China. Land Degradation & Development, 23: 62- 71. DOI 10.1002/ldr.1050 Prokop, P., Poręba, G. J. 2012. Soil erosion

  12. Is Brazil Actually Ready to be a World Economic Power? (CSL Issue Paper, Volume 13-11, July 2011)

    DTIC Science & Technology

    2011-07-01

    Brazil, Porto Brasil : Economic Sectors, http://www.brasil.gov.br/sobre/economy/economy-sectors/agriculture-and-cattle- raising-agropecuaria (accessed...April 15, 2011); Federal Government of Brazil, “Porto Brasil : Federal Government Budget,” http://www.brasil.gov.br/sobre/ brazil/government/federal

  13. PFOA y PFOS - PREGUNTAS Y RESPUESTAS

    EPA Pesticide Factsheets

    Preguntas y respuestas sobre la decisión de la EPA de publicar avisos de salud sobre el ácido perfluorooctanoico (PFOA) y el sulfonato de perfluorooctano (PFOS) para proporcionar información a los operadores de sistemas de agua potable y funcionarios estat

  14. Annual 1921 : The Reasons for a Disaster

    DTIC Science & Technology

    2013-04-17

    Las Responsabilidades del Desastre. Ecce Homo: prueba documental y aportes inéditos sobre las causas del derrumbamiento. Madrid: Biblioteca Nueva...documental y aportes inéditos sobre las causas del derrumbamiento. Madrid: Biblioteca Nueva. 1922 Usborne, C.V. The conquest of Morocco. London

  15. Breast Cancer Epidemiology in Puerto Rico

    DTIC Science & Technology

    2013-06-30

    familiar de enfermedades cronicas, su historial residencial, el uso de vitaminas y medicinas , informacion sobre la menstruacion y los hijos que ha...cronicas, direccion actual e historial residencial, uso de vitaminas y medicinas , informacion sobre la menstruacion y los Consent Formed Approved by the

  16. Breast Cancer Epidemiology in Puerto Rico

    DTIC Science & Technology

    2010-06-01

    historial personal y familiar de enfermedades cronicas, su historial residencial, el uso de vitaminas y medicinas , informacion sobre la menstruacion y los...cronicas, direccion actual e historial residencial, uso de vitaminas y medicinas , informacion sobre Ia menstruacion y los embarazos y alguna

  17. Novel Regulatory Mechanisms for Generation of the Soluble Leptin Receptor: Implications for Leptin Action

    PubMed Central

    Schaab, Michael; Kausch, Henriette; Klammt, Juergen; Nowicki, Marcin; Anderegg, Ulf; Gebhardt, Rolf; Rose-John, Stefan; Scheller, Juergen; Thiery, Joachim; Kratzsch, Juergen

    2012-01-01

    Background The adipokine leptin realizes signal transduction via four different membrane-anchored leptin receptor (Ob-R) isoforms in humans. However, the amount of functionally active Ob-R is affected by constitutive shedding of the extracellular domain via a so far unknown mechanism. The product of the cleavage process the so-called soluble leptin receptor (sOb-R) is the main binding protein for leptin in human blood and modulates its bioavailability. sOb-R levels are differentially regulated in metabolic disorders like type 1 diabetes mellitus or obesity and can, therefore, enhance or reduce leptin sensitivity. Methodology/Principal Findings To describe mechanisms of Ob-R cleavage and to investigate the functional significance of differential sOb-R levels we established a model of HEK293 cells transiently transfected with different human Ob-R isoforms. Using siRNA knockdown experiments we identified ADAM10 (A Disintegrin And Metalloproteinase 10) as a major protease for constitutive and activated Ob-R cleavage. Additionally, the induction of lipotoxicity and apoptosis led to enhanced shedding shown by increased levels of the soluble leptin receptor (sOb-R) in cell supernatants. Conversely, high leptin concentrations and ER stress reduced sOb-R levels. Decreased amounts of sOb-R due to ER stress were accompanied by impaired leptin signaling and reduced leptin binding. Conclusions Lipotoxicity and apoptosis increased Ob-R cleavage via ADAM10-dependent mechanisms. In contrast high leptin levels and ER stress led to reduced sOb-R levels. While increased sOb-R concentrations seem to directly block leptin action, reduced amounts of sOb-R may reflect decreased membrane expression of Ob-R. These findings could explain changes of leptin sensitivity which are associated with variations of serum sOb-R levels in metabolic diseases. PMID:22545089

  18. 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…

  19. 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

  20. Soils and landforms from Fildes Peninsula and Ardley Island, Maritime Antarctica

    NASA Astrophysics Data System (ADS)

    Michel, Roberto F. M.; Schaefer, Carlos E. G. R.; López-Martínez, Jerónimo; Simas, Felipe N. B.; Haus, Nick W.; Serrano, Enrique; Bockheim, James G.

    2014-11-01

    cryoturbic) are the most important soil classes; Leptosols/Entisols, Gleysols/Aquents and Cambisols/Inceptisols also occur, all with gelic properties, and with varying faunal influences. Both soil classification systems are adequate to distinguish the local pedogenesis processes. The WRB system is broader, since it was designed to be applied in all Polar Regions; the family classes adopted by the ST were effective in separating soils with important differences with regard to texture and gravel content, all important attributes accounting for the ecological succession and periglacial processes. An altitudinal organization of landforms and processes can be recognized from geomorphological mapping. Periglacial features are dominant above 50 m a.s.l. although are present at lower altitude.

  1. [Effect of temperature, rainfall and soil properties on farmland soil nitrification].

    PubMed

    Sun, Bo; Zheng, Xian-qing; Hu, Feng; Li, Hui-xin; Kong, Bin; Wang, Lian-li; Sui, Yue-yu

    2009-01-01

    Climate conditions, soil properties and management practices control soil nitrification process which affects nitrogen cycling and balance in agro-ecosystems. The interaction of temperature, rainfall, soil type and fertilization on the soil nitrification process was studied by a soil transplantation experiment installed in 3 experiment stations of Chinese Ecological Research Network, i.e., Hailun, Fenqiu and Yingtan Agroecological Experiment Station, which represents middle temperature, warm temperature and middle subtropical zone, respectively. Three types of cropland soils were selected, i.e., neutral black soil (Phaeozem), alkaline Chao soil (Cambisol) and acidic red soil (Acrisol). Then one-meter depth soil profiles for each soil were transplanted in 3 stations to build the field experiment. The two-year experimental results (2006-2007) showed soil nitrification intensity (SNI) changed with the temperature and rainfall during the maize tasseling stage. From Hailun to Yingtan, with an increase of monthly average temperature from 22.3 degrees C to 26.8 degrees C and the monthly rainfall from 100.8 mm to 199.6 mm, SNI decreased by 64.2%-67.2% for black soil, 52.1%-52.5% for Chao soil, and 41.7%-75.2% for red soil, respectively. There were significant negative correlations between SNI and temperature and rainfall, with a correlation coefficient of r = -0.354 (p < 0.01) and r = -0.290 (p < 0.01), respectively. The total number of soil nitrobacteria and the intensity of soil nitrification was affected by soil types, which increased in a sequence of Chao soil > black soil > red soil. Among soil properties, pH affected SNI significantly, with a correlation coefficient of r = 0.551 (p < 0.01). In generally, climate condition (temperature and rainfall), soil type and fertilization present an integrated impact on soil nitrification process, and there were significant interactions of climate x soil type, climate x fertilization, soil type x fertilization, and climate x

  2. Automated multi-point mini-disk infiltrometer measurements of unsaturated hydraulic conductivity

    NASA Astrophysics Data System (ADS)

    Klipa, Vladimir; Sacha, Jan; Snehota, Michal; Dohnal, Michal; Zumr, David; Tacheci, Pavel

    2014-05-01

    Unsaturated hydraulic conductivity function K(h) is one of hydraulic characteristics needed for numerical modeling of water flow and solute transport in the vadose zone. Tension infiltrometer is advantageous tool to conduct the measurement of unsaturated hydraulic conductivity in field under near saturated conditions. Manually operated minidisk infiltrometers are often used for performing infiltration experiments, but their disadvantage is that permanent attendance is needed during experiments. Therefore automatization of the tension infiltrometer is desirable. A new automated multi-disk tension infiltrometer has been designed at the Faculty of Civil Engineering, Czech Technical University in Prague to facilitate the measurements of near-saturated hydraulic conductivity. Infiltration experiment performed by device is simultaneously carried out by six tension mini-disk infiltrometer modules forming a fixed matrix as they are held by a lightweight aluminum frame. This setup is divided into the two groups of three infiltrometers. Each triplet of modules is controlled by Mariotte`s bottle. Therefore it is possible to conduct six simultaneous infiltration experiments at two different pressure heads. Amount of infiltrated water is registered via changes of buoyant force of vertical bar attached to the weighing sensor in each infiltrometer module and recorded automatically using datalogger. Cumulative infiltration and volumetric flux are calculated and displayed in real time. Near saturated hydraulic conductivity is determined from cumulative infiltration data using nonlinear optimization and improved procedure of Zhang. Device developed was to date tested on four experimental locations. Two sites were arable land (Nucice and Kopaninsky stream) and two located in headwater catchments (Sumava and Jizera Mountains). Soils at experimental sites were classified as Cambisols (empirical van Genuchten parameters α and n ranged from 0.007 to 0.043 cm-1 and from 1.13 to 1

  3. 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

  4. 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

  5. Water repellence assessment in humid mediterranean carbonated environments: influence of shrubland species

    NASA Astrophysics Data System (ADS)

    Oscar, Gonzalez-Pelayo; Vicente, Andreu; Luis, Rubio Jose; Carla Sofia, Ferreira; Dinis, Ferreira Antonio Jose

    2010-05-01

    The importance of natural or induced (fire) water repellence in terms of water redistribution in the soil profile, reduction in soil infiltration capacity and thus, in runoff magnification, is well established. Hydrophobicity has been identified around the world in different climatic conditions, land covers, soil and vegetation types. Regarding soil and vegetation, many studies are based on coarse acidic soils with pine forest, eucalyptus, deciduous trees, grassland, cropland, chaparral vegetation type, and lately in shrublands. However, few studies are related to shrubland in wet Mediterranean carbonated environments. This work is oriented to the study of soil water repellence in these environments by means of WDPT. The study was carried out in Podentes (Coimbra), central Portugal, on 4 ha of shrubland (mainly Quercus coccifera, Pistacia lentiscus and Arbutus unedo), developed on Umbric leptosol and Calcaric cambisol soil types (WRB). The WDPT was assessed depending on the shrubland type, slope orientation, soil depth (0-2 cm and 2-5 cm) and on different soil fractions (<2 mm, 2-1 mm, 1-0.25 mm and <0.25 mm). Soil organic matter, pH and carbonate content were also determined. The largest hydrophobicity (56% strong persistence and 44% slight persistence) was measured on the soil fraction of <0.25 mm of the soil surface layer under A. unedo. Soil water repellence decreased with depth. The studied shrubland species showed an increasing trend on the soil hydrophobicity persistence: A. unedo > Q. coccifera ≈ P. lentiscus; and depending on the orientation: NE > SW. Direct relationships were obtained between the soil organic matter content and the log WDPT on almost all the surface soil samples. The soil pH and carbonate content did not display correlation with soil water repellence. The different hydrophobic compounds generated by waxes and resins of the different shrubland types, which could be incorporated to the soil as binding agents, seem to be the explanation

  6. 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

  7. Relief-induced soil zones at the Cretaceous sandstone-mudstone contact in the Stolowe Mountains, SW Poland

    NASA Astrophysics Data System (ADS)

    Kabala, Cezary; Waroszewski, Jaroslaw; Jezierski, Pawel

    2014-05-01

    Regolith translocation on mountain slope built of stratified rocks creates mixed or layered covers which may obliterate the actual transitions of rocks. The covers are seldom delineated on geological maps due to their insignificant thickness; however, enough large to influence the soil morphology and ecological functions. A toposequence of six soil sections situated at the contact of Cretaceous sandstone and mudstone was investigated to evaluate the influence of relief-position and morphological processes on slope cover formation, as well as soil and forest habitat arrangement. At least four distinct soil zones were distinguished in the 400 m long catena: (1) Arenosols and sand Regosols zone, on active fluvial cones and blocky covers directly below sandstone cliffs; (2) upper mid-slope zone of Podzols developed from sandstone-derived materials with periglacial features (solifluction) in the subsoil; (3) lower mid-slope and foot-slope zone of Stagnosols and Planosols with prolonged water stagnation over the impermeable subsoil developed from sandstone or mixed sandstone-mudstone regolith; excess of water is also the sign of mudstone bedrock that forces lateral water flow; and (4) toe-slope zone of Cambisols developed from the mudstone regolith. Past and present-day morphological processes have broadened the area mantled by sandstone-derived materials from upper-slope and created transitional materials that enhanced soil variability and multi-step zonality over the presumably sharp contact of sandstone and mudstone bedrocks. Financed in part by the Ministry of Science and Higher Education of Poland (project number: N N310 435938) and National Science Centre (project OPUS 2012/05/B/NZ9/03389). Lorz, C., Heller, K., Kleber, A. (2011): Stratification of the regolith continuum - a key property for processes and functions of landscapes. Z Geomorphol 55, 3: 277-292. Sauer, D., Felix-Heningsen, P. (2006): Saprolite, soils and sediments in the Rhenish Massif as records of

  8. Combining geomorphological mapping and near surface geophysics (GPR and ERT) to study piping systems

    NASA Astrophysics Data System (ADS)

    Bernatek-Jakiel, Anita; Kondracka, Marta

    2016-12-01

    This paper aims to provide a more comprehensive characterization of piping systems in mountainous areas under a temperate climate using geomorphological mapping and geophysical methods (electrical resistivity tomography - ERT and ground penetrating radar - GPR). The significance of piping in gully formation and hillslope hydrology has been discussed for many years, and most of the studies are based on surface investigations. However, it seems that most surface investigations underestimate this subsurface process. Therefore, our purpose was to estimate the scale of piping activity based on both surface and subsurface investigations. We used geophysical methods to detect the boundary of lateral water movement fostering pipe development and recognize the internal structure of the underlying materials. The survey was carried out in the Bereźnica Wyżna catchment, in the Bieszczady Mountains. (Eastern Carpathians, Poland), where pipes develop in Cambisols at a mean depth of about 0.7-0.8 m. The geophysical techniques that were used are shown to be successful in identifying pipes. GPR data suggest that the density of piping systems is much larger than that detectible from surface observations alone. Pipe length can be > 6.5-9.2% (maximum = 49%) higher than what surface mapping suggests. Thus, the significance of piping in hillslope hydrology and gully formation can be greater than previously assumed. These results also draw attention to the scale of piping activity in the Carpathians, where this process has been neglected for many years. The ERT profiles reveal areas affected by piping as places of higher resistivity values, which are an effect of a higher content of air-filled pores (due to higher soil porosity, intense biological activity, and well-developed soil structure). In addition, the ERT profiles show that the pipes in the study area develop at the soil-bedrock interface, probably above the layers of shales or mudstones which create a water restrictive layer

  9. 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

  10. Long-term retention of (137)Cs in three forest soil types with different soil properties.

    PubMed

    Suchara, Ivan; Sucharová, Julie; Holá, Marie; Pilátová, Helena; Rulík, Petr

    2016-07-01

    Current (137)Cs activity concentrations were studied at three localities in individual soil horizons of Stagnosol, Arenic Podzol and Haplic Cambisol soil units in soil blocks with dimensions of 20 × 20 × 40 cm situated below pine canopies (n = 3) and spruce canopies (n = 3), and below small canopy gaps, at least 15 × 15 m in area (n = 3 + 3), which have probably endured since 1986. The main zone of (137)Cs accumulation in all the localities was found to be in the organic horizons (H and F). No significant transport and accumulation of (137)Cs into illuvial soil horizons (Bm, Bs or Bhs, Bv and Bv/IIC) was found. The estimated current total (137)Cs activity concentrations in the soil blocks 40 cm in depth were only slightly higher below the coniferous canopy than they were below nearby canopy gaps. The inventory of (137)Cs in the soils was found to be in accordance with the estimated (137)Cs inputs from the Chernobyl fallout and from global fallout. The low amounts of (137)Cs found accumulated in the aboveground biomass (mosses, grasses, needles) did not substantially bias the studied radiocaesium balance in the soils. The vertical migration rate of (137)Cs in soils (cm/year) had a tendency to be higher below canopies than below canopy gaps and below pine canopies than below spruce canopies. We expected the current (137)Cs activity concentrations in the individual soil horizons to be related to the studied soil parameters: pH (H2O), pH (CaCl2), content of organic matter and mineral portion and portion of humic and fulvic acid contents (Q4/6). However, this was not confirmed. Similarly, we observed a weak tendency toward higher (137)Cs activity in soils below the canopy than in soils below canopy gaps. The available gaps used in our study may have been too small, and they may have been affected by an accumulation of litter and humus containing (137)Cs from the surrounding plots situated below neighbouring canopies.

  11. Temperature response of denitrification rate and greenhouse gas production in agricultural river marginal wetland soils.

    PubMed

    Bonnett, S A F; Blackwell, M S A; Leah, R; Cook, V; O'Connor, M; Maltby, E

    2013-05-01

    Soils are predicted to exhibit significant feedback to global warming via the temperature response of greenhouse gas (GHG) production. However, the temperature response of hydromorphic wetland soils is complicated by confounding factors such as oxygen (O2 ), nitrate (NO3-) and soil carbon (C). We examined the effect of a temperature gradient (2-25 °C) on denitrification rates and net nitrous oxide (N2 O), methane (CH4 ) production and heterotrophic respiration in mineral (Eutric cambisol and Fluvisol) and organic (Histosol) soil types in a river marginal landscape of the Tamar catchment, Devon, UK, under non-flooded and flooded with enriched NO3- conditions. It was hypothesized that the temperature response is dependent on interactions with NO3--enriched flooding, and the physicochemical conditions of these soil types. Denitrification rate (mean, 746 ± 97.3 μg m(-2)  h(-1) ), net N2 O production (mean, 180 ± 26.6 μg m(-2)  h(-1) ) and net CH4 production (mean, 1065 ± 183 μg m(-2)  h(-1) ) were highest in the organic Histosol, with higher organic matter, ammonium and moisture, and lower NO3- concentrations. Heterotrophic respiration (mean, 127 ± 4.6 mg m(-2)  h(-1) ) was not significantly different between soil types and dominated total GHG (CO2 eq) production in all soil types. Generally, the temperature responses of denitrification rate and net N2 O production were exponential, whilst net CH4 production was unresponsive, possibly due to substrate limitation, and heterotrophic respiration was exponential but limited in summer at higher temperatures. Flooding with NO3- increased denitrification rate, net N2 O production and heterotrophic respiration, but a reduction in net CH4 production suggests inhibition of methanogenesis by NO3- or N2 O produced from denitrification. Implications for management and policy are that warming and flood events may promote microbial interactions in soil between distinct microbial communities and increase

  12. Assessment of forest nutrient pools in view of biomass potentials - a case study from Austria oak stands

    NASA Astrophysics Data System (ADS)

    Yan, S.; Bruckman, V. J.; Glatzel, G.; Hochbichler, E.

    2012-04-01

    As one of the renewable energy forms, bio-energy could help to relieve the pressure which is caused by growing global energy demand. In Austria, large area of forests, traditional utilization of biomass and people's desire to live in a sound environment have supported the positive development of bio-energy. Soil nutrient status is in principle linked with the productivity of the aboveground biomass. This study focuses on K, Ca and Mg pools in soils and aboveground biomass in order to learn more on the temporal dynamics of plant nutrients as indicators for biomass potentials in Quercus dominated forests in northeastern Austria. Three soil types (according to WRB: eutric cambisol, calcic chernozem and haplic luvisol) were considered representative for the area and sampled. We selected nine Quercus petraea dominated permanent plots for this study. Exchangeable cations K, Ca and Mg in the soils were quantified in our study plots. Macronutrients pools of K, Ca and Mg in aboveground biomass were calculated according to inventory data and literature review. The exchangeable cations pool in the top 50 cm of the soil were 882 - 1,652 kg ha-1 for K, 2,661 to 16,510 kg ha-1 for Ca and 320 - 1,850 kg ha-1 for Mg. The nutrient pool in aboveground biomass ranged from 29 to 181 kg ha-1 for K, from 56 to 426 kg ha-1 for Ca and from 4 to 26 kg ha-1 for Mg. The underground exchangeable pools of K, Ca and Mg are generally 10, 22 and 58 times higher than aboveground biomass nutrient pools. Our results showed that the nutrient pools in the mineral soil are sufficient to support the tree growth. The levels of soil nutrients in particular K, Ca and Mg in our study areas are reasonably high and do not indicate the necessity for additional fertilization under current silvicultural practices and biomass extraction rate. The forest in our study areas is in favorable condition to supply biomass as raw material for energy utilization.

  13. The Precision Field Lysimeter Concept

    NASA Astrophysics Data System (ADS)

    Fank, J.

    2009-04-01

    The understanding and interpretation of leaching processes have improved significantly during the past decades. Unlike laboratory experiments, which are mostly performed under very controlled conditions (e.g. homogeneous, uniform packing of pre-treated test material, saturated steady-state flow conditions, and controlled uniform hydraulic conditions), lysimeter experiments generally simulate actual field conditions. Lysimeters may be classified according to different criteria such as type of soil block used (monolithic or reconstructed), drainage (drainage by gravity or vacuum or a water table may be maintained), or weighing or non-weighing lysimeters. In 2004 experimental investigations have been set up to assess the impact of different farming systems on groundwater quality of the shallow floodplain aquifer of the river Mur in Wagna (Styria, Austria). The sediment is characterized by a thin layer (30 - 100 cm) of sandy Dystric Cambisol and underlying gravel and sand. Three precisely weighing equilibrium tension block lysimeters have been installed in agricultural test fields to compare water flow and solute transport under (i) organic farming, (ii) conventional low input farming and (iii) extensification by mulching grass. Specific monitoring equipment is used to reduce the well known shortcomings of lysimeter investigations: The lysimeter core is excavated as an undisturbed monolithic block (circular, 1 m2 surface area, 2 m depth) to prevent destruction of the natural soil structure, and pore system. Tracing experiments have been achieved to investigate the occurrence of artificial preferential flow and transport along the walls of the lysimeters. The results show that such effects can be neglected. Precisely weighing load cells are used to constantly determine the weight loss of the lysimeter due to evaporation and transpiration and to measure different forms of precipitation. The accuracy of the weighing apparatus is 0.05 kg, or 0.05 mm water equivalent

  14. Long term impact of different tillage practices on soil C sequestration potential

    NASA Astrophysics Data System (ADS)

    Valboa, Giuseppe; Lagomarsino, Alessandra; Papini, Rossella; Brandi, Giorgio; Elio Agnelli, Alessandro; Simoncini, Stefania; Vignozzi, Nadia; Pellegrini, Sergio

    2013-04-01

    Long-term experiments provide important information on the impact of agricultural management practices on soil quality. In 1994, a trial was started to investigate the effects of four different tillage systems on organic carbon and physical properties of a Calcari Fluvic Cambisol loam soil under continuous maize. The tillage practices compared were: conventional tillage by mould-board ploughing to 40 cm depth (DP); ripper sub-soiling to 40-45 cm (RS); shallow tillage by mould-board ploughing to 20 cm depth (SP); minimum tillage by disk harrowing to 10-15 cm (DH). Soil carbon pool, bulk density, macroporosity and aggregate stability were studied at different depth increments (0-10, 10-20, 20-30 and 30-40 cm) and by two repeated samplings (in 1999 and 2011), in order to evaluate their temporal evolution under the different tillage systems. For a better understanding of mechanisms leading to C sequestration, a qualitative characterization of soil organic matter (OM) was performed by acid hydrolysis (HCl 6N), in order to separate the labile and the recalcitrant fractions. After 18 years of treatments we hypothesized changes in OM content and quality, as well as in its vertical distribution, due to tillage practices. At the end of the trial, soil total organic carbon (TOC) stock increased in the surface layers under DH (to 10 cm depth), RS (to 20 cm depth) and SP (to 10 cm depth), while it was unchanged under DP. When considering the whole 0-40 cm layer, all tillage treatments resulted in no significant variation in TOC stock. OM quality and its evolution over time showed well defined differences among treatments: the OM recalcitrant fraction increased under RS (up to 30 cm depth), decreased under DP (up to 40 cm depth) and showed no significant changes under DH and SP. The negative impact of DP on C stabilization was confirmed by a significant decrease of the recalcitrant to TOC ratio in the whole sampled layer. In conclusion, DP showed the worst impact on C storage

  15. Soil respiration in tropical seasonal forest of Southern Vietnam

    NASA Astrophysics Data System (ADS)

    Avilov, Vitaly; Anichkin, Alexandr; Descherevskaya, Olga; Evdokimova, Elena; Nguyen Van, Thinh; Novichonok, Artyom; Do Phong, Luu; Kurbatova, Julia; Lopes de Gerenyu, Valentin

    2013-04-01

    Soil respiration was monitored as a part of a complex research of carbon balance in Nam Cat Tien National Park in Southern Vietnam (NCT site in AsiaFlux index). The study area is described as a tropical monsoon valley tall-stand forest at altitude about 156 m above sea level, mean annual air temperature is 26.2°C, with fluctuations of monthly averaged temperatures within 4°C; mean annual precipitation is 2470 mm with a distinct alternation of wet and dry seasons (Dong Phu weather station, 1976-1990). Measurements were made every 10-15 days during year 2012 at 6 plots that differ in soil and forest type, mostly in Lagerstroemia- or Dipterocarpus-dominated tree stands. Five chambers Ø162 mm were installed at each plot. CO2 concentration was defined with LI-820 gas analyser and 20 ml syringes (three syringes/samples per chamber) up to August 2012, and by means of closed-loop continuous field analysis from August on. Our studies have shown significant temporal and spatial variability of soil respiration in tropical rainforest. Namely, highest annual CO2 efflux rates were calculated for cambisols under lagerstroemia-dominated tree stand and for light sandy fluvisols under dipterocarpus-dominated tree stand (1694.3±546.0 and 1628.1±442.7 gC•m-2•y-1 respectively). Noteworthy is that the content of organic carbon in these soils varies utterly. Lowest annual CO2 efflux rate was calculated for clay-slate leptosols under dipterocarpus-dominated tree stand (972.7±716.5 gC•m-2•y-1). We also observed a significant impact of termites activity on site-scale spatial variability of soil respiration. Seasonal patterns of soil respiration rates were conformed for all plots except one on sandy soils. The beginning of rainy season in April did not result in higher soil respiration rates, but rates did rise in August - October, at the end of rainy season. Apparently this pattern is related to the accumulation of decomposed organic matter in soil and to the deficient

  16. Using semivariogram scaled to the sample design of heavy metals

    NASA Astrophysics Data System (ADS)

    Medeiros Bezerra, Joel; Machado Siqueira, Glécio; Dafonte Dafonte, Jorge; Vidal Vazquez, Eva; Paz González, Antonio

    2013-04-01

    The "sampling intensity" issue is of important application to precision agriculture. About 80%-85 % of the total error in precision in agriculture results from the field sampling preceding the application of fertilizers and corrective practices. The spatial sampling design used to characterize the spatial variability of soil attributes is crucial to science studies. The sample planning for interpolation of a regionalized variable may use several criteria, which could be best selected from the estimated semivariogram from a previously established grid. The objective of this study was to evaluate the use of the semivariogram scaled to improve the sample design of heavy metals in an experimental plot. The study area surface is 6 ha and is located at Castro Ribeiras de Lea, Lugo, Spain. The geographical coordinates of the study area are: latitude 43° 09 '49''N and longitude 7° 29' 47''W, with average elevation of 410 m and average slope of 2 %. The mean annual temperature is 11.2 °C and mean annual rainfall is 930 mm (data 1961-1990). The soil is classified with Cambisol and the parent material are sediments from tertiary and quaternary. Heavy metals were initially sampled at 40 points randomly distributed in the study area. The heavy metals analyzed in this study were: Pb, Cd, Cu and Ni. Data were initially analyzed using descriptive statistics and geostatistical tools. The scaled semivariogram was built with the aim of setting a single theoretical semivariogram all elements studied. Subsequently, the software SANOS was used to determine the sampling optimization of new sampling points of the heavy metals. The spatial variability analysis of the studied elements using the scaled semivariogram showed the existence of a relationship between the spatial variability of these elements. The gaussian model was adjusted for Pb, Cd and Ni, and spherical models for the Cu element. The semivariogram scaled theoretical adjusted to elements in four study was Gaussian, with a

  17. Conversion of cropland to grassland: increasing or decreasing soil organic carbon?

    NASA Astrophysics Data System (ADS)

    Ammann, Christof; Leifeld, Jens; Calanca, Pierluigi; Neftel, Albrecht; Fuhrer, Jürg

    2010-05-01

    Conversion of cropland to permanent grassland is often expected to sequester atmospheric CO2 by increasing soil organic carbon (SOC) stocks. We investigated this possibility under realistic management conditions on the field scale. We compared the development of the carbon (C) balance and SOC stocks of intensively (high nitrogen input and frequent cutting) and extensively (no nitrogen input, infrequent cutting) managed grassland after conversion from an arable rotation. The study was carried out at a site in the northern lowlands of Switzerland with a temperate climate and a soil classified as Eutri-Stagnic Cambisol. As a first approach, C balance was assessed by measuring C fluxes in and out of the ecosystem including net CO2 exchange by eddy flux measurements, as well as C import by organic fertilizer and C export by harvest. In a second approach, SOC stocks (0-45 cm depth) were quantified at the beginning (2001) and at the end (2006) of a 5-year observational period. An equivalent soil mass of 500 kg m-2 was sampled. Results showed very similar SOC stocks in 2001 of 13-14 kg C m-2 for the intensive and extensive field. Over the 5-year period, the observed mean annual increase for the intensive field was small and not significant, whereas for the extensive field a significant decrease of 0.22 kg C m-2 yr-1 was found. The other approach (flux budget) also indicated a generally positive carbon balance (C accumulation) for the intensive field and a negative balance (C loss) for the extensive field, with substantial inter-annual variations in relation to growing season length and soil moisture. Both, stock and flux measurements, revealed a consistent difference between the C balance of the two management types (about 0.25 kg C m-2 yr-1), which also appeared in simulations with the mechanistic grassland model PROGRASS. However, absolute values for the C balance differed between the two experimental approaches. The flux measurements indicated higher gains to the

  18. 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

  19. Short and mid-term effects of different biochar additions on soil GHG fluxes

    NASA Astrophysics Data System (ADS)

    Maier, Regine; Soja, Gerhard; Friesl-Hanl, Wolfgang; Dunst, Gerald; Kitzler, Barbara

    2015-04-01

    The application of biochar (BC) to soils may have a positive influence on physico-chemical soil properties and the mitigation of greenhouse gas (GHG) emissions. Furthermore, biochar contributes to a long-term soil carbon sequestration. The aim of this study is to explore short and mid-term effects (one day up to six months) of different BC-compost applications on soil GHG emissions, particularly CO2, CH4, N2O and NOx. In addition, compounds of the nitrogen cycle like NH4+, NO3- and the microbial biomass nitrogen (Nmic) were measured. For this purpose a field experiment in Kaindorf (Styria/Austria, gleyic Cambisol, loamy, 376 m.a.s.l.) with 16 plots and four different treatments was conducted. K = no BC-compost mixture but fertilized (NH4SO4) corresponding to T3 in 2013; T1 = 1 % BC-compost mixture, no addition of N in 2013 and 2014; T2 = 0.5 % BC-compost mixture, + 175 kg N ha-1 in 2013 and 2014; T3 = 1% BC-compost mixture, + 350 kg N ha-1 in 2013. Nitrogen was added as (NH4)2SO4 directly to the freshly produced biochar before mixing it with compost. Greenhouse gas fluxes (CO2, CH4, N2O) were measured monthly from closed chambers in the field over a period of six months, starting 30 days before BC application and ended shortly before harvesting in September. For the analysis of nitric oxide (NO) fluxes intact soil cylinders were taken from each plot and incubated at the laboratory at ambient air temperature. Mineral N contents were measured by the extraction with KCl-solution and the microbial biomass with chloroform-fumigation extraction (CFE). Biochar application to our agricultural soil showed no reduction potential of NO emissions, but N2O fluxes were significantly lower at T1 and T3 compared to treatment K. Gaseous N fluxes of the pure BC-compost mixture and the additional N fertilization with (NH4)2SO4 led to enormous gaseous N losses in form of N2O and NO. However, after application to the soil, fluxes were only higher for a short time period. We suggest

  20. 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

  1. Greenhouse gas emissions and stocks of soil carbon and nitrogen from a 20-year fertilised wheat-maize intercropping system: A model approach.

    PubMed

    Zhang, Xubo; Xu, Minggang; Liu, Jian; Sun, Nan; Wang, Boren; Wu, Lianhai

    2016-02-01

    Accurate modelling of agricultural management impacts on greenhouse gas emissions and the cycling of carbon and nitrogen is complicated due to interactions between various processes and the disturbance caused by field management. In this study, a process-based model, the Soil-Plant-Atmosphere Continuum System (SPACSYS), was used to simulate the effects of different fertilisation regimes on crop yields, the dynamics of soil organic carbon (SOC) and total nitrogen (SN) stocks from 1990 to 2010, and soil CO2 (2007-2010) and N2O (2007-2008) emissions based on a long-term fertilisation experiment with a winter-wheat (Triticum Aestivum L.) and summer-maize (Zea mays L.) intercropping system in Eutric Cambisol (FAO) soil in southern China. Three fertilisation treatments were 1) unfertilised (Control), 2) chemical nitrogen, phosphorus and potassium (NPK), and 3) NPK plus pig manure (NPKM). Statistical analyses indicated that the SPACSYS model can reasonably simulate the yields of wheat and maize, the evolution of SOC and SN stocks and soil CO2 and N2O emissions. The simulations showed that the NPKM treatment had the highest values of crop yields, SOC and SN stocks, and soil CO2 and N2O emissions were the lowest from the Control treatment. Furthermore, the simulated results showed that manure amendment along with chemical fertiliser applications led to both C (1017 ± 470 kg C ha(-1) yr(-1)) and N gains (91.7 ± 15.1 kg N ha(-1) yr(-1)) in the plant-soil system, while the Control treatment caused a slight loss in C and N. In conclusion, the SPACSYS model can accurately simulate the processes of C and N as affected by various fertilisation treatments in the red soil. Furthermore, application of chemical fertilisers plus manure could be a suitable management for ensuring crop yield and sustaining soil fertility in the red soil region, but the ratio of chemical fertilisers to manure should be optimized to reduce C and N losses to the environment.

  2. The effect of biochar amendment on the soil microbial community - PLFA analyses and 13C labeling results

    NASA Astrophysics Data System (ADS)

    Watzinger, A.; Feichtmair, S.; Rempt, F.; Anders, E.; Wimmer, B.; Kitzler, B.; Zechmeister-Boltenstern, S.; Horacek, M.; Zehetner, F.; Kloss, S.; Richoz, S.; Soja, G.

    2012-04-01

    The effects of biochar amendment on plant growth and on the chemical / physical soil characteristics are well explored but only few studies have investigated the impact on soil microorganisms. The response of the soil microbial community to biochar amendment was investigated by phospholipid fatty acid (PLFA) analysis in (i) a large scale pot experiment, (ii) a small scale pot experiment using 13C labeled biochar and (iii) an incubation study using 13C labeled biochar. In the large scale pot experiment, three different agricultural soils from Austria (Planosol, Cambisol, Chernozem) and four different types of biochar were investigated. In total, 25 treatments with 5 replicates each were set up and monitored over a year. The results from the pot experiments showed no significant influence of biochar amendment on the total microbial biomass in the first 100 days after biochar addition. However, discriminant analysis showed a distinction of biochar and control soils as well as a strong effect of the pyrolysis temperature on the microbial composition. The effect of biochar was dependent on the type of soil. In the Planosol, some PLFAs were affected positively, especially when adding biochar with a low pyrolysis temperature, in the first month. In the long term, microbial community composition altered. Growth of fungi and gram negative bacteria was enhanced. In the Chernozem, PLFAs from various microbial groups decreased in the long term. Variability in the incubation study was low. Consequently, many PLFAs were significantly affected by biochar amendment. Again, in the Planosol, gram negative bacteria, actinomycetes and, after 2 weeks, gram positive bacteria increased under biochar amendment whereas in the chernozem total microbial biomass and gram positive bacteria were negatively affected in the long term. The 13C labeling studies confirmed the low degradability of the biochar, i.e. no alteration of the content and the δ13C in the soil organic matter within 100 days

  3. Long term drainage alters plant biodiversity and soil C- and N-storage

    NASA Astrophysics Data System (ADS)

    Wolf, K.; Bol, R.; Dungait, J. A. J.; Dixon, L.; Dhanoa, D.; Beaumont, D.; Wiesenberg, G. L. B.

    2012-04-01

    Moisture and slope position can have a strong influence on soil properties and plant communities. In a long term permanent grassland experiment, sub-surface drainage was introduced in 1982 on some plots of Rowden Moor at North Wyke (SW UK). The soil is a Stagnic vertic Cambisol with a dense clay layer at shallow depth. After drainage the plant community had shifted from a Lolium perenne dominated grassland with patches of Juncus sp. towards a typical grassland plant community dominated by Lolium perenne and Trifolium sp. In addition, soil carbon and nitrogen concentrations significantly decreased. This is related to a smaller contribution of plant-derived organic matter to soil due to the change in plant community structure, and the enhanced mineralization of soil organic matter (SOM) under lower soil moisture. However, for C:N ratios neither plants nor soil did reveal any drainage related change arguing for an identical degradability of plant and soil organic matter. Furthermore the δ13C values tend to get more negative in soil, which could be related to the changing plant community. For δ15N no changes were observed, which was surprising as increase δ15N values were expected due to the increase in legumes on the drained plot. Changes in the chemical composition of SOM were also examined using compositional changes of soil n-alkanes. A shift in the alkane abundance occurs from the upper part of the slope (dominated by n-C31), to the bottom parts (n-C29 enriched). The carbon preference index and average chain length of alkanes correlated between undrained and drained plots and decreased down slope. Similarly, several alkane ratios like n-C27/n-C31 declined, due to the enhanced mineralization. Hence, the molecular pattern changed on the one hand due to changing contribution of plant derived organic matter and on the other hand because of changing preservation of organic matter in soil. The study showed that drainage has a long term effect on the plant community

  4. Chronostratigraphical investigations on Pleistocene fluvioglacial terraces of NW-Austria

    NASA Astrophysics Data System (ADS)

    Terhorst, B.

    2009-04-01

    Investigations on paleopedology and Quaternary stratigraphy were carried out in the area of fluvioglacial terraces of the rivers Inn and Traun/Enns. Research projects have been financed by the German Research Foundation (DFG) and the ICSU Grant Programme. Detailed studies were carried out on paleosols and loess sequences of different ages. The investigations of the research group were focused on loess/paleosol sequences located on top of Riss terraces (OIS 6 and older) as well as in areas with Mindel and Günz terraces. Loess records of the last glacial/interglacial cycle can be well observed in the study areas. Generally, the Eemian soil (O/S 5e) is developed as a reddish Bt-horizon in fluvioglacial gravels. U/Th-datings of calcites in the fluvioglacial sediments are indicating that soil formation took place in the catchment area about 113.000 ± 4.400 ka (Terhorst et al., 2002). The interglacial paleosol was truncated and a redeposited colluvial layer was deposited on top of the Bt-horizons containing charcaol with characteristic relicts of coniferous trees. After this land surface destabilisation phase, sedimentation of loess became the predominant process. Pedogenesis in form of a brown paleosol occurred, which partly has been redeposited. The pedocomplex is characterized by intense bioturbation of steppe animals. OSL-datings show that this part of the sequence belong to the Middle Würmian stage. The pedocomplex is overlain by a Cambisol corresponding to the youngest Middle Würmian interstadial. The paleosol is covered by thick loess deposits of the Upper Pleniglacial. Well-developed Tundragleysols subdivide the loess deposits. The uppermost soil corresponds to the Holocene Luvisol that includes hydromorphic properties. Older fluvioglacial terraces of Mindel and Günz age (in the classical stratigraphy) show a completely different structure of the covering layers (c.f. Kohl, 1999). In this case, several thick interglacial paleosols are embedded within records

  5. Is it efficient to co-compost and co-vermicompost green waste with biochar and/or clay to reduce CO2 emissions? A short-term laboratory experiment on (vermi)composts with additives.

    NASA Astrophysics Data System (ADS)

    Barthod, Justine; Rumpel, Cornélia; Paradelo, Remigio; Dignac, Marie-France

    2016-04-01

    Intensive farming practices can lead to a depletion of soil organic matter, negatively impacting important soil properties such as structural stability, fertility and C storage. The addition of organic amendments such as compost and vermicompost, rich in carbon, helps maintaining soil organic matter levels or restoring degraded soils. Composting and vermicomposting are based on stabilization of organic matter through the mineralization of easily decomposable organic matter compounds, therefore releasing greenhouse gases, including CO2. The aim of this study was to evaluate the global potential reduction of such emissions by the use of additives (2:1 clay and/or biochar): during (vermi)composting processes and after use of the final products as soil amendments. We hypothesized that the interactions between the additives and organic matter may lead to carbon stabilization and that such interactions may be enhanced by the presence of worms (Eisenia). We added in different proportions clay (25% or 50%), biochar (10%) and a mixture of biochar (10%) with clay (25%) to pre-composted green waste. The CO2 emissions of the composting and vermicomposting processes were measured during 21 days. After that, the amendments were added to a loamy cambisol soil and the CO2 emissions were monitored during 30 days of a laboratory experiment. The most efficient treatments in terms of reducing global CO2 emissions were the co-vermicomposting process with 25% clay followed by co-composting with 50% clay and with 10% biochar plus 25% clay. In this treatment (vermicompost with 25% clay), the carbon emissions were decreased by up to 44% compared to regular compost. Addition of biochar reduced CO2 emissions only during composting. Co-composting with biochar could be a promising avenue to limit global CO2 emissions whereas in presence of worms clay additions are better suited. These findings suggest that the presence of worms increased the formation of organo-mineral associations and thus C

  6. 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

  7. 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

  8. 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

  9. Amount, determining factors and spatial distribution of soil organic carbon storage in the Dano catchment (Southwest Burkina-Faso)

    NASA Astrophysics Data System (ADS)

    Hounkpatin, O.; Op de Hipt, F.; Bossa, A. Y.; Welp, G.; Amelung, W.

    2015-12-01

    The ability to project and to mitigate the impacts of climate change is closely related to the evaluation of soil organic carbon (SOC) content and stock across different types of land use and soil groups. Therefore, this study aimed at estimating the surface and subsoil organic carbon stocks in different land use systems and across various soil groups. A further aim was to assess the spatial variability of SOC content and stocks and how this is controlled by climate and site properties. The Random Forest (RF) modelling was used and compared to Ordinary Kriging interpolation (OK) for the topsoil SOC and stock. About 70 soil profiles were described along 16 transects with 197 samples collected from different horizons up to 1 m depth where possible. In addition, 1205 samples were collected within an intensive auger grid mapping. Mid-infrared spectroscopy and partial least-squares analysis were used as a fast and low-cost technique to handle the large amount of samples for the SOC estimation. The natural/semi natural vegetation recorded the highest SOC stock in the topsoil (28.6 t C ha-1) as compared to the cropland (25.5 t C ha-1). Over 1 m depth, Gleysols (87.4 t C ha-1) stored the highest amount of SOC stock followed by the Cambisols (76. t C ha-1) and the Plinthosols (73.1 t C ha-1) while the lowest were found in the Lixisols (57.8 t C ha-1). For the topsoil, the RF model revealed soil properties such as cation exchange capacity (CEC) and stone content as main factors affecting SOC content variability while CEC and bulk density were the major drivers for the subsoil. The carbon stock variability was mainly affected by the CEC and the reference soil group in the topsoil while horizon thickness and bulk density constituted the main factors for the subsoil. The geostatistical evaluation proved that the SOC content in the Dano catchment has a moderate spatial autocorrelation while the carbon stock was strongly spatially dependent. The RF gave a better prediction for

  10. 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

  11. Numerical modeling of shallow subsurface runoff on cultivated soil with temporary variable structure

    NASA Astrophysics Data System (ADS)

    Zumr, David; Klípa, Vladimír; Dušek, Jaromír; Dostál, Tomáš

    2014-05-01

    Temporary variable properties of periodically cultivated soils are one of the crucial factors that must be taken into account to understand flow processes on agriculture catchments. Soil structure is a property that is often considered as a static rather than dynamic. This could be a reasonable assumption for compacted subsoil, but not for the plough layer. The man-made and natural processes such as an overuse of heavy machinery, tillage, plowing, harvest, quick vegetation and root growth, edaphon activity, raindrops kinetic energy, freezing, thawing etc. cause recurrent cycles of the topsoil loosening, compaction and surface sealing. Deformation of the structure causes reduction of volume and connectivity of inter-aggregate voids and eroded fine particles clog the macropores and preferential pathways, the infiltration capacity decreases. Originally connected large pores normally serve as a quick bypass for infiltrating water, therefore, based on the state of the topsoil structure one can expect different runoff mechanisms ranging from hypodermic to surface flow. The aim of the contribution is to examine the runoff dynamics along the inclined slope under different structural properties of the topsoil. We will present a numerical analysis of the effect of variable preferential domain ratio on subsurface runoff, the simulation results will be qualitatively compared to measured hydrographs at the catchment. We used a combination of physically based macroscopic models S1D and HYPO. In the S1D the dual permeability approach with two coupled Richards equations is used, the simultaneously operating HYPO code is based on a diffusion wave (Boussinesq eq.). The study is based on monitoring of water regime of the cultivated soils on experimental catchment Nucice (Central Bohemia, Czech Republic). The soil is classified as Cambisol, texture ranges from loam to clay loam classes. Soil is conservatively tilled till depth of approximately 17 cm, below that a compacted subsoil was

  12. Investigation of the main causes of forest decay in a Hungarian Pinus forest

    NASA Astrophysics Data System (ADS)

    Gulyás, Krisztina; Bidló, András; Horváth, Adrienn

    2015-04-01

    Hungary has several places where the changing conditions (climate, water or soil) have an influence on the natural ecosystems. Lack of the adaptation capacity can lead to the mortality of the affected forests. In our study we try to find the reasons of the decay of a Hungarian old-growth forest (150-200 years old) in Fenyőfő - which is growing on protected area - whether it is caused by the soil properties and other abiotic variables or it is the result of the drying climate. On the studied area 119 samples from 20 soil profiles have been collected to find the causes of the tree mortality. The characteristic soil types are Luvisols, Cambisols, Arenosols mainly sand (56%) or loam (42%) by the physical assessment, but we found buried humus layer in a few cases that improves the water and nutrient supply of soils. Due to this favourable property the CaCO3 content appeared near to the surface, which hinders the vegetation in water utilization or water uptake. The average pH(H2O) of topsoil was between 4.2 and 5.5, where the leaching was characteristic and we found CaCO3 in deeper layers. The effects of climate change on the Pinus forest were also analysed. We used gridded station data from the Hungarian Meteorological Service for the time period 1961-2013. It contains daily, monthly and yearly time series for precipitation and temperature means and extremes. The meteorological data clearly show, that the mean annual temperature of the research plot increased drastically (~1°C). We also analysed the frequency of extreme high temperatures such as the total number of summer days (daily maximum temperature Tmax>25°C), hot days (Tmax>30°C) and extremely hot days (Tmax>35°C). This frequency of these days showed an increase in Fenyőfő, which caused higher water utilization and water deficiency. The annual precipitation sum decreased in the last few decades but this signal is not significant. The intensity and the variability of the precipitation in the vegetation

  13. 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

  14. The role of tree uprooting dynamics on the dynamics of Fe (Mn, Al and Si) forms in different forest soils

    NASA Astrophysics Data System (ADS)

    Tejnecký, V.; Samonil, P.; Boruvka, L.; Nikodem, A.; Drabek, O.; Valtera, M.

    2013-12-01

    Tree uprooting dynamics plays an important role in the development of forest ecosystems. This process causes bioturbation of soils and creates new microenvironments which consist of pits and mounds. These microtopographical forms could persist for some thousands of years. Pits and mounds undergo different pedogenesis in comparison to adjacent undisturbed soils. The stage of pedogenesis can be assessed according to the results of fractionation of Fe and also partially Mn, Al and Si. The main aim of this contribution is to assess the fractionation of Fe, Mn, Al and Si for three different soil regions. Soil samples were collected at three localities occurred along hypothetical gradient of soil weathering and leaching processes: The first was a (spruce)-fir-beech natural forest in the Razula region. The second location is the same type of natural forest in Zofin; however it has contrasting lithology. Both these natural forests are located in the Czech Republic (CZ). The third forest was a northern hardwood forest in Upper Peninsula, Michigan, USA. The prevailing soil types - Haplic Cambisols have formed on flysch parent materials in the Razula reserve; Entic Podzols have developed on granite residuum at the Zofin reserve, and Albic Podzols occurred in outwash parent materials at the Michigan sites (Šamonil et al., in press). In total 790 soil samples were analysed. These samples were collected from 5 depths (0-10, 15, 30, 50 and 100 cm) within the pit, mound and control, currently undisturbed position. For each sample, content of Fe (and Mn, Al, Si) forms: exchangeable, crystalline, and amorphous together with organically complexed Fe were determined. We generally observed an increased content of Fe soil forms in the pits of studied treethrows. The content of Fe forms increased along depth gradient at the disturbed sites. However, exchangeable Fe was most abundant in the 0-10cm layer which corresponds to the A horizon. Naturally, if present, the E horizon exhibited

  15. Assessment of fluorescence EEM vs. Liquid-state 1H-NMR spectroscopy for the characterization of natural OM in agricultural soils from the UK and Spain

    NASA Astrophysics Data System (ADS)

    Fernandez, Maria Luisa; Collins, Chris; Clark, Joanna; Parras-Alcantara, Luis; Lozano-Garcia, Beatriz

    2014-05-01

    Humification is the group of biological and chemical reactions that leads to the formation of humus, which contributes to nutrient and water retention, as well as to the accumulation of carbon. Here, we assess the potential to measure the degree of humification of organic matter by fluorescence spectroscopy, by comparing indices calculated from the fluorescence emission-excitation matrix (EEM) with measurements of aromaticity determined by Nuclear Magnetic Resonance (NMR). In this study, two contrasting European soils were compared: cambisols with from agricultural land in eastern Andalusia (South Spain, Mediterranean climate) and Reading, (South-East England, Temperate climate). Both the Mediterranean and British soils were managed with conventional tillage. Samples were collected at depths ranging from 13.3cm to 60cm down the soil profiles. All samples were then dried and sieved to 2mm. Fluorescence measurements were taken for the whole soil profile. Prior to fluorescence, the supernatant of the samples was extracted with the Ghani et al. (2003) method. This was followed by a hot water extraction (80oC) which is considered more exhaustive. Fluorescence was measured at an emission wavelength from 300 to 600nm at 5-nm increments and an excitation of 240-450nm at 5-nm increments. Fluorescence indexes were calculated as the ratio of intensities at 450 over 500nm with an excitation of 370nm, as described by Cory et al. (2010), NMR was applied to the first horizon (A depth between 5.7cm and 12cm in this case), due to time constraints. The method for extracting the supernatant was the same as per the hot extraction for the fluorescence samples. The aromaticity of isolated fulvic acid samples was calculated as the ratio of the area of aromatic hydrogen region to the total area of the H-NMR spectrum (% aromaticity). Other soil parameters measured were dissolved organic carbon (DOC), absorbance, texture, carbonates, pH, total carbon, and total nitrogen. Assessment of

  16. Influence of vegetation, soil and antecedent soil moisture on the variability of surface runoff coefficients at the plot scale in the eastern alps

    NASA Astrophysics Data System (ADS)

    Chifflard, P.; Kohl, B.; Markart, G.; Kirnbauer, R.

    2009-04-01

    very high surface runoff coefficients, independent of the antecedent soil moisture. Cambisols show a great variance of surface runoff coefficients. These results are the basis for the characterisation of different soil-vegetation complexes by their surface runoff coefficient and they also describe the potential surface runoff of a catchment.

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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

  2. Seasonal changes of principal anions contents and other soil properties in acidified forest soils

    NASA Astrophysics Data System (ADS)

    Drabek, O.; Tejnecky, V.; Bradová, M.; Němeček, K.; Šebek, O.; Zenáhlíková, J.; Boruvka, L.

    2011-12-01

    Acidification of forest soil is a natural degradation process enhanced by anthropogenic activities. The depositions of principal inorganic anions are the main external acidity inputs to forest ecosystems. The aim of the study was to describe seasonal changes of sulphate and nitrate behaviour in soils and influence of their depositions on the selected forest soil properties. The following soil properties were investigated: soil pH, DOC, selected elements contents and Al species content. The Jizera Mountains area (Czech Republic) was chosen as a representative soil mountainous ecosystem affected by acidification. Soil and precipitation samples were collected at monthly intervals from April to October during the years 2008-2010 under beech and spruce stands. Prevailing soil types were classified as Alumic Cambisols under beech and Entic Podzols under spruce stands (according to FAO classification). Soil samples were collected from surface fermentation (F) and humified (H) organic horizons and subsurface B horizons (cambic or spodic). The collected soil samples were analyzed immediately in a "fresh" state. Unsieved fresh samples were extracted by deionised water and content of anions (sulphate, nitrate, chloride and fluoride) in these extracts were determined by ion-exchange chromatography (IC); the Al speciation was performed by means of HPLC/IC. The extracts were also used for determination of main elements content (Al, Ca, Mg, Ca, Na and Fe) by means of ICP-OES. Content of anions and main elements content, pH and conductivity were determined also in the precipitation samples (throughfall, stemflow and bulk). Statistically significant differences in distributions of monitored anions between the tested soil horizons were observed. The highest content of sulphate was determined in F and B horizons. On the contrary, contents of nitrate were highest in F horizons and lowest in B horizons. Higher annual variability in the investigated characteristics was proven for

  3. 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

  4. Measurements of heat fluxes and soil moisture patterns in the field conditions

    NASA Astrophysics Data System (ADS)

    Sanda, M.; Snehota, M.; Haase, T.; Wild, J.

    2011-12-01

    New combined thermal and soil moisture unit coded TMS2 is presented. It is a prototype designed on good experience with TMS1. The device combines three thermometers for use approximately at -10, 0 and +15 cm relative to soil surface when installed vertically. Soil moisture measurement is performed based on time domain transmission (TDT) principle for the full range of soil moisture. Presented new version incorporates lifetime power supply for approximately 5 year operation and life time permanent data storage (0.5 mil logs) if values are acquired every 10 minutes. Lifetime operation log accompanies lifetime data storage with lockable data blocks. Data are retrieved by contact portable pocket collector. Both vertical/surface or buriable/subsurface installation is possible thanks to additional communication interface on demand. Original model TMS1, proved durability in harsh outdoor environment with good functioning in wet conditions withstanding mechanical destruction. Extended testing in the sandstone area of the National Park Bohemian Switzerland, Czech Republic is performed since 2009 by the Institute of Botany of the ASCR. Results of long-term measurement at hundreds of localities are successfully used for i) evaluation of species-specific environmental requirements (for different species of plants, bryophytes and fungi) and ii) extrapolation of microclimatic conditions over large areas of rugged sandstone relief with assistance of accurate, LiDAR based, digital terrain model. TMS1 units are also applied for continuous measurement of temperature and moisture of coarse woody debris, which serves as an important substrate for establishment and growth of seedlings and is thus crucial for natural regeneration of many forest ecosystems. The TMS1 sensors have been tested and calibrated in soil laboratories of Czech Technical University in Prague for three soil materials: arenic cambisol, podzol and quartz sand, showing good linearity and minor influence of the

  5. Assessment of factors related to heavy metals distribution in abandoned mining soils in Madrid, central Spain

    NASA Astrophysics Data System (ADS)

    Torres, Manuel; Carral, Pilar; Alvarez, Ana M.; Hernández, Zulimar; Lorena, Recio-Vázquez; Marques, Maria J.; Almendros, Gonzalo

    2013-04-01

    Exploitation of metallic mineral deposits and its subsequent abandonment in last decades has lead to significant environmental hazard for natural systems. The present study concerns the distribution and mobility of heavy metals and trace elements mainly As, Cu, Cd, Co, Mn and V, in sulphide-rich soils. The site studied (Sierra de Guadarrama, Garganta de los Montes, Madrid) is at 1200 m asl. Soils are Humic and Dystric Cambisols (WRB) developed on gneisses; the main minerals consist of sulphides and include chalcopyrite, pyrite, marcasite, galena and arsenopyrite. Concentration data of the different species of heavy metals as dependent variables in addition to a series of independent variables mainly soil organic matter were subjected to multivariate chemometric treatments including multidimensional scaling (MDS), principal component analysis (PCA) and support vector machine (SVM) for a preliminary survey on the possible role of soil organic matter in the distribution and speciation of heavy metals in soils. The soil heavy metals speciation was determined using the BCR (Community Bureau of Reference, European Commission) sequential extraction procedure and analysed by ICP-MS. The total contents of these elements were calculated as the sum of the four BCR fractions. The results showed element concentrations decreasing with the distance from the source of pollution. The highest amounts of As and Mn, and Cu, Cd, Co and V were found at 10 and 100 m respectively. These values exceed the allowed limits of the environmental regulation. The percentages of extractable elements (step one of BCR) in relation to total elements show that Cu and Cd were significantly more easily extractable than the other elements. Metal availability in soils was generally controlled by total metal concentration. Data processing techniques coincided in pointing out the association of high levels of organic matter with the concentrations of elements extracted just in the most available forms: i

  6. Transfer of hexazinone and glyphosate through undisturbed soil columns in soils under Christmas tree cultivation.

    PubMed

    Dousset, S; Chauvin, C; Durlet, P; Thévenot, M

    2004-10-01

    Field studies monitoring pesticide pollution in the Morvan region (France) have revealed surface water contamination by some herbicides. The purpose of this study was to investigate in greater detail the transport of two herbicides, used in Christmas tree production in the Morvan, under controlled laboratory conditions. Thus, the leaching of hexazinone (3-cyclohexyl-6-dimethyl-amino-1-methyl-1,3,5-triazine-2,4 (1H,3H) dione) and glyphosate (N-(phosphono-methyl-glycine)) through structured soil columns was studied using one loamy sand and two sandy loams from sites currently under Christmas tree cultivation in the Morvan. The three soils were cultivated sandy brunisol [Sound reference base for soils, D. Baize, M.C. Girard (Coord.), INRA, Versailles, 1998, 322 p] or, according to the FAO [FAO, World reference base for soil resources, ISSS-ISRIC-FAO, FAO, Rome, Italy, 1998], the La Garenne was an arenosol and the two other soils were cambisols. The clay contents of the soils ranged from 86 to 156 g kg(-1) and the organic carbon ranged from 98 to 347 g kg(-1). After 160 mm of simulated rainfall applied over 12 days, 2-11% of the applied hexazinone was recovered in the leachate. The recovery was much higher than that of glyphosate, which was less than 0.01%. The greater mobility of hexazinone might be related to its much lower adsorption coefficient, K(oc), 19-300 l kg(-1), compared with 8.5-10231 l kg(-1) for glyphosate (literature values). Another factor that may explain the higher amounts of hexazinone recovered in the leachates of the three soil columns is its greater persistence (19.7-91 days) relative to that of glyphosate (7.9-14.4 days). The mobility of both herbicides was greater in the soils with higher gravel contents, coarser textures, and lower organic carbon contents. Moreover, glyphosate migration seems negatively correlated not only to soil organic carbon, but also to aluminium and iron contents of soils. This soil column study suggests that at the

  7. Multiscale Analysis of Soil Porosity from Hg Injection Curves in Soils from Minas Gerais, Brazil

    NASA Astrophysics Data System (ADS)

    Vidal Vázquez, E.; Miranda, J. G. V.; Paz-Ferreiro, J.

    2012-04-01

    The soil pore space is a continuum extremely variable in size, including structures smaller than nanometres and as large as macropores or cracks with millimetres or even centimetres size. Pore size distributions (PSDs) affects important soil functions, such as transmission and storage of water, and root growth. Direct and indirect measurements of PSDs are currently used to characterize soil structure. Mercury injection porosimetry is useful for assessing equivalent pore size diameters in the range from about 0,5 nm to 100 μm. Here, the multifractal formalism was employed to describe Hg injection curves measured in duplicate samples collected on 54 horizons from 19 profiles in Minas Gerais state, Brazil. Ten of the studied profiles were classified as Ferralsols (Latosols, Oxisols). Besides these, other wide different soil groups were sampled, including Nitisol, Acrisol, Alisol, Luvisol, Planosol, Cambisol, Andosol and Leptosol. Clay content varied from 4 to 86% and pore volume in the range from 100 to 0.005 μm was between 5.52 a 53.76 cm3100g-1. All the horizons taken on Ferralsols and Nitisols as well as in Bt argic horizons from Acrisol Alisol, Luvisol and Planosol clearly showed a bimodal pore size distribution. Pore volume in the range from 100 to 0.005 μm and microporosity (0,2-0.005 μm) showed a significant relationship with clay content an Al2O3. All the Hg injection data sets studied soil showed remarkably good scaling trends and could be fitted reasonably well with multifractal models. The capacity dimensions, D0, was not significantly different from the Euclidean dimension. The entropy dimension, D1, varied from 0.590 to 0.946 , whereas the Hölder exponent of order zero, α0was between 1.027 and 1.451, and these two parameters showed a lineal negatives relationship, as expected. The highest D1 values, ranging from 0.913 to 0.980, were obtained for the Leptosol, whereas the lowest D1 values, ranging from 0.641 to 0.766 corresponded to the Nitisol. This

  8. 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.

  9. 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

  10. [Improvement of the knowledge on allergic cross-reactions between two drug groups: beta-lactams and NSAIDS].

    PubMed

    Sánchez-Quiles, I; Nájera-Pérez, M D; Calleja-Hernández, M Á; Martinez-Martínez, F; Belchí-Hernández, J; Canteras, M

    2013-01-01

    Objetivos: Identificar oportunidades de mejora, sobre el conocimiento disponible del personal sanitario (en concreto a personal médico, farmacéutico y de enfermería), sobre reacciones alérgicas cruzadas (RAC) de penicilinas y AINEs. Método: Estudio prospectivo cuasiexperimental pre-exposición en un hospital de 412 camas. Se realizó una valoración del conocimiento sobre RAC de penicilinas y AINEs, a través de encuestas anónimas, antes (1a encuesta) y después (2a encuesta) de la implantación de una serie de medidas de mejora: protocolo “paciente alérgico a medicamentos”, tarjeta de bolsillo, póster resumen de información y charlas divulgativas. Las propias encuestas sirvieron de hoja de recogida de datos y el análisis estadístico se llevó a cabo con el programa SPSS v18.0. Resultados: La media de errores en las 1as encuestas sobre “RAC en paciente alérgico a penicilinas” y sobre “RAC en paciente alérgico a AINEs”, fue de 20,53 y 27,62, respectivamente. La media de errores en las 2as encuestas sobre “RAC en paciente alérgico a penicilinas” y sobre “RAC en paciente alérgico a AINEs”, fue de 2,27 y 7,26, respectivamente. Todos los resultados se consideraron significativos para un nivel 945;< 0,05. Conclusiones: - No se dispone de un nivel adecuado de conocimiento sobre RAC de penicilinas y AINEs, lo que justifica la realización de un ciclo de mejora. - Tras la implantación de las medidas de mejora se aprecia un aumento en el nivel de conocimiento sobre RAC en penicilinas y AINEs, en los grupos de estudio.

  11. 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

  12. Modelling global change impacts on soil carbon contents of agro-silvo-pastoral Mediterranean systems

    NASA Astrophysics Data System (ADS)

    Lozano-García, Beatriz; Muñoz-Rojas, Miriam; Parras-Alcántara, Luis

    2016-04-01

    To assess the impact of climate change on soil organic C (SOC) stocks in agro-silvo-pastoral environments, different models have been applied worldwide at local or regional scales, such as as RothC (Francaviglia et al., 2012) or CENTURY (Alvaro-Fuentes et al., 2012). However, some of these models may require a high number of input parameters or can underestimate the effect of soil depth. CarboSOIL (Muñoz-Rojas et al., 2013) is an empirical model based on regression techniques and developed to predict SOC contents at standard soil depths (0-25, 25-50 and 50-75 cm) under a range of climate and/or land use change scenarios. CarboSOIL has been successfully applied in different Mediterranean areas ,e.g. Southern Spain (Muñoz-Rojas et al., 2013; Abd-Elmabod et al., 2014), Northern Egypt (Muñoz-Rojas et al., 2014) and Italy (Muñoz-Rojas et al., 2015). In this study, CarboSOIL was applied in the Cardeña and Montoro mountain range Natural Park. This area covers 385 km2 and is located within Sierra Morena (Córdoba, South Spain) and has a semiarid Mediterranean climate. It is characterized by agro-silvo-pastoral systems. The Mediterranean evergreen oak woodland (MEOW-dehesa) is savanna-like open woodland ecosystem characterized by silvopastoral uses, being an ancient human modified Mediterranean landscape (Corral-Fernández et al., 2013; Lozano-García and Parras-Alcántara 2013). The most representative soils in the Cardeña and Montoro mountain range Natural Park are Cambisols, Regosols, Leptosols and Fluvisols. These soils are characterized by low fertility, poor physical conditions and marginal capacity for agricultural use, together with low organic matter (OM) content due to climate conditions (semiarid Mediterranean climate) and soil texture (sandy). The model was applied at different soil depths: 0-25, 25-50 and 50-75 cm (Parras-Alcántara et al., 2015) considering land use and climate changes scenarios based on available global climate models (IPPC, 2007). A

  13. Vegetative filter strips efficiency controlling soil loss and trapping herbicides in two olive orchards at the short-term

    NASA Astrophysics Data System (ADS)

    de Luna, Elena; Guzmán, Gema; Gómez, José A.

    2014-05-01

    The optimization of water use in a semi-arid climate is based on an optimal use of rainwater adopting management practices that prevent and/or control runoff. This is a key point for increasing the economic and environmental sustainability of agriculture due to the minimization of diffuse pollution associated to runoff and to sediment and chemical transport. One strategy is the establishment of vegetative filters strips that prevent pesticides (Stehle et al. 2011), herbicides (Vianello et al. 2005), fertilizers (Withers et al. 2009) and runoff-sediment (Campo-Bescós et al. 2013) from entering streams or surface water reservoirs. To evaluate the short-term risks associated with the use of herbicides a trial was designed in two olive groves located in Benacazón (Sevilla) and Cabra (Córdoba) both with an average steepness of 11%. Two different management systems were evaluated, bare soil and bare soil with vegetative filter strips. Pre-emergence herbicides were applied and analysed at the beginning of the trial by chromatography GC-MS and after each rainfall event both in soil and sediment. Runoff and soil losses were measured, as well. The results obtained from this study show that soil management practices such as, the use of vegetative filter strips results in a reduction of soil losses and runoff. This it is translated in the improvement of soil quality and a reduction of water pollution caused by the use of herbicides. This information will improve the understanding of insufficiently known aspects and it will help to increase the knowledge for a better implementation of sustainable management practices at a farm scale and at larger temporal scale. References: Campo-Bescós, M. A., Muñoz-Carpena, R., & Kiker, G. (2013) Influencia del suelo en la eficiencia de la implantación de filtros verdes en un distrito de riego por superficie en medio árido. En Estudios de la Zona no Saturada del Suelo, Vol. XI: 183-187. Stehle, S., Elsaesser, D., Gregoire, C., Imfeld

  14. Conózcanos

    EPA Pesticide Factsheets

    Principal de la EPA: información sobre el Administrador o la Administradora, los altos directivos; ubicaciones y direcciones de las oficinas; presupuesto, la planificación y los resultados de rendimiento

  15. Materiales en Marcha para el Esfuerzo Bilingue-Bucultural (Materials on the March for the Promotion of Bilingualism/Biculturalism), December 73.

    ERIC Educational Resources Information Center

    San Diego City Schools, CA.

    This newsletter is designed to promote bilingual/bicultural education. Articles in this issue include: "Una Mejor Comprension de la Cultura Hispanoamericans" ("A Better Understanding of Hispanoamerican Culture"), "Portuguese Science Materials,""Comentario Sobre Materiais Portugueses" ("Commentary on…

  16. 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.

  17. 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 ...

  18. 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.

  19. 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.

  20. Ventilation Guidance To Promote the Safe Use of Spray Polyurethane Foam (SPF) Insulation, Incluyendo la Versión de Español

    EPA Pesticide Factsheets

    This guidance describes basic ventilation principles and strategies to help protect workers and building occupants and promote the safe use of spray polyurethane foam (SPF) insulation. Guia para la ventilacion sobre la application del aerosol de espuma.

  1. PubMed

    Conroy-Ferreccio, Gabriel

    2017-02-01

    En relación con el artículo "Influencia del sobrepeso y obesidad sobre el tiempo de equilibrio del deuterio, pero no en el agua corporal total y la composición corporal en mujeres mayores de 60 años", es necesario discutir sobre cuál es la mejor definición de sobrepeso y obesidad en adultos mayores en este tipo de estudios.

  2. Chinese Economic Coercion Against Taiwan: A Tricky Weapon to Use

    DTIC Science & Technology

    2007-01-01

    UNISCI discussion papers, Madrid: Unidad de Investigación sobre Seguridad y Cooperación Internacional, January 2004. 3 The National People’s Congress is...disruption as a result of such Internet attacks. Since 2000, mainland hackers have attempted numerous cyberattacks designed to harass, disrupt, or...papers, Madrid: Unidad de Investigación sobre Seguridad y Cooperación Internacional, January 2004. Online at http://www.ucm.es/info/unisci/TUNG4M.pdf

  3. A Revision of the Argyritarsis Section of the Subgenus Nyssorhynchus of Anopheles (Diptera: Culicidae)

    DTIC Science & Technology

    1988-01-01

    Middle America. Contrib. Am. Entomol. Inst. (Ann Arbor) 1(2):1-17. 1967. Estudios sobre mosquitos (Diptera, Culicidae). Ia. Un proyecto para un estudio...N) pessoai na fase larvaria. Rev. Bras. Malariol. 2:38-48. Galvao, A. L. A. and F. A. D. Amaral 1938. Sobre urn novo anofelino de Campos do Jordao...Salubr. Taxonomia y distribution. Mex., D. F., P* identification de larvas en cuarta fase de Rev. Biol. Trop. 4:27-34. identification de larvas

  4. Behavioral and Physiological Response of Musca domestica to Colored Visual Targets

    DTIC Science & Technology

    2012-01-01

    1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty...OF PAGES 8 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev...Observaciones sobre la busqueda de sitios de reposo y estudio experimental sobre la seleccion de colores porMusca domestica en el ambiente natural. M.S

  5. Taxonomy and Biology of Phlebotomine Vectors of Human Disease

    DTIC Science & Technology

    1987-12-31

    Diptera, Psychodidae). Rev. Med. Exp., Lima 13:125-134. Blancas, F. & A. Herrer. 1959-1960. Estudios sobre la enfermedad de Carrion en el valle...distribuipo geografica e da incidencia por tipo de capture de 64 especies identificadas. Revta Ser. Exp. Saude Pub. 2:817-842. Damasceno, R. G., 0. R...verruga en el Departamento de Cajamarca. II. Observaciones entomologicas. Rev. Med.3 exp., Lima 2:354-361. 1949-1951. Estudios sobre leishmaniasis

  6. 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.

  7. Life Cycle Evolution and Systematics of Campanulariid Hydrozoans

    DTIC Science & Technology

    2004-09-01

    development, and pattern. W.H. Freeman and Company, San Francisco. Blanco OM. 1967. Estudio critico sobre las especies del genero Silicularia Meyen...Estudio critico sobre las especies del genero Silicularia Meyen 1834. Revista del Museo de La Plata (Nueva Serie) IX (70): 217-241. Blanco OM. 1968. Nueva...diagnosis del genero . Neotropica 13(42): 117-120. Blanco OM. 1968. Nueva contribucion al conocimiento de la fauna marina hidroide. Revista del Museo de

  8. Evidence of exposure to cytostatic drugs in healthcare staff: a review of recent literature.

    PubMed

    Martín Lancharro, Pablo; De Castro-Acuña Iglesias, Nuria; González-Barcala, Francisco-Javier; Moure González, José Domingo

    2016-11-01

    Objetivo: Disponer de la evidencia mas actual y conocer las medidas a aplicar para evitar la exposicion laboral a citostaticos. Método: Se realizo una busqueda bibliografica en las bases de datos MEDLINE, COCHRANE PLUS y WEB OF SCIENCE con los terminos “surface contamination”, “antineoplastic drug”, “drug preparation”, “occupational exposure”, “safe handling” y “closed-system transfer device” para el periodo 2010- 2015. Resultados: Se seleccionaron 13 articulos para la revision. Estos articulos corresponden a hospitales de USA, Canada, Japon, Australia, Espana, Portugal y Alemania. En todos ellos se ha encontrado contaminacion por farmacos citostaticos en mas de 15 superficies distintas con concentraciones que van desde los 1,69 ng/cm2 hasta 4,784 μg/cm2. Los farmacos determinados han sido ciclofosfamida, ifosfamida, 5-fluorouracilo, metotrexato, paclitaxel, cisplatino, gemcitabina y docetaxel. El sistema cerrado reduce la contaminacion de las superficies de trabajo significativamente, pero no la elimina. Conclusiones: Se verifica la presencia de contaminacion por farmacos citostaticos en numerosos hospitales de los 5 continentes. En todos los casos se ha encontrado contaminacion en la cabina, en el suelo frente a la cabina y en otros lugares de la farmacia. El farmaco mas frecuentemente encontrado es la ciclofosfamida. El sistema empleado mas eficaz para reducir la contaminacion es el uso de dispositivos cerrados de transferencia (CSTD-closed system transfer device).

  9. Hydrodynamic characteristics of the western Doñana Region (area of El Abalario), Huelva, Spain

    NASA Astrophysics Data System (ADS)

    Trick, Thomas; Custodio, Emilio

    espacialmente y juega un papel importante; disminuye el valor neto de la recarga al acuífero para dejarlo en 0,4 a 0,6 de lo que se calcula mediante un balance de agua en el suelo. La sección modelada sirve para estudiar el efecto de la extracción de agua subterránea sobre la profundidad del nivel freático mediante la substracción del flujo vertical, que se calcula mediante una fórmula de hidráulica de pozos para el acuífero semiconfinado profundo. El resultado es una disminución de la evapotranspiración freática, del flujo al arroyo de la Rocina y de la frecuencia de inundación de las lagunas. La substitución del bosque de eucaliptus por vegetación nativa puede elevar los niveles freáticos e incluso reactivar antiguos "caños" tributarios al arroyo de La Rocina.

  10. ANALYSIS OF INFORMATION CONTENT AND GENERAL QUALITY OF OBESITY AND EATING DISORDERS WEBSITES.

    PubMed

    Hernández-Morante, Juan José; Jiménez-Rodríguez, Diana; Cañavate, Rubén; Conesa-Fuentes, María del Carmen

    2015-08-01

    Introducción: actualmente, el uso de Internet como fuente de información sobre temas de salud, y más concretamente sobre trastornos alimentarios, está aumentando enormemente. Sin embargo, al no existir una regulación precisa, la información disponible puede variar en calidad y fiabilidad. Objectivo: el objetivo del presente trabajo fue determinar tanto la calidad general como la información contenida en las páginas web sobre obesidad y trastornos de la alimentación más visitadas en España. Métodos: se introdujeron consecutivamente los términos ‘obesidad’, ‘anorexia’ y ‘bulimia’ en el buscador Google®. La calidad general de las páginas web se analizó mediante dos test, la certificación internacional HonCode ® y el test de Bermúdez-Tamayo et al.; la calidad de la información se analizó específicamente con el test DISCERN. Resultados: no observamos diferencias significativas en la calidad general entre las diferentes patologías estudiadas (p = 0,197), aunque las páginas web sobre anorexia obtuvieron las menores puntuaciones. Además, todas las páginas web mostraron deficiencias significativas respecto a la calidad de la información (p = 0,032). No obstante, las páginas sobre obesidad mostraron mayor calidad que las de anorexia. Discusión: la calidad general de las páginas sobre trastornos nutricionales es moderada, pero la calidad de la información que contienen es bastante deficiente. Hay que destacar que las páginas web sobre anorexia mostraron tanto la peor calidad como la peor información.

  11. Acceptability of an Embodied Conversational Agent-based Computer Application for Hispanic Women

    PubMed Central

    Wells, Kristen J.; Vázquez-Otero, Coralia; Bredice, Marissa; Meade, Cathy D.; Chaet, Alexis; Rivera, Maria I.; Arroyo, Gloria; Proctor, Sara K.; Barnes, Laura E.

    2015-01-01

    There are few Spanish language interactive, technology-driven health education programs. Objectives of this feasibility study were to: 1) learn more about computer and technology usage among Hispanic women living in a rural community; and 2) evaluate acceptability of the concept of using an embodied conversational agent (ECA) computer application among this population. A survey about computer usage history and interest in computers was administered to a convenience sample of 26 women. A sample video prototype of a hospital discharge ECA was administered followed by questions to gauge opinion about the ECA. Data indicate women exhibited both a high level of computer experience and enthusiasm for the ECA. Feedback from community is essential to ensure equity in state of the art dissemination of health information. Hay algunos programas interactivos en español que usan la tecnología para educar sobre la salud. Los objetivos de este estudio fueron: 1) aprender más sobre el uso de computadoras y tecnología entre mujeres Hispanas que viven en comunidades rurales y 2) evaluar la aceptabilidad del concepto de usar un programa de computadora utilizando un agente de conversación encarnado (ECA) en esta población. Se administro una encuesta sobre el historial de uso y del interés de aprender sobre computadoras fue a 26 mujeres por muestreo de conveniencia. Un ejemplo del prototipo ECA en forma de video de un alta hospitalaria fue administrado y fue seguido por preguntas sobre la opinión que tenían del ECA. Los datos indican que las mujeres mostraron un alto nivel de experiencia con las computadoras y un alto nivel de entusiasmo sobre el ECA. La retroalimentación de la comunidad es esencial para asegurar equidad en la diseminación de información sobre la salud con tecnología de punta. PMID:26671558

  12. [Screening and early care programmes in children with autism spectrum disorders].

    PubMed

    Canal-Bedia, Ricardo; García-Primo, Patricia; Santos-Borbujo, José; Bueno-Carrera, Gloria; Posada-De la Paz, Manuel

    2014-02-24

    Introduccion. La necesidad de la deteccion y de tratamientos eficaces de forma temprana para los trastornos del espectro autista es algo actualmente aceptado tanto por las sociedades profesionales como por la administracion sanitaria. Una informacion actualizada y sintetizada sobre los procedimientos de cribado y las tecnicas de atencion temprana para niños con trastornos del espectro autista facilitara la puesta en marcha de mejores dispositivos de deteccion y la labor de asesoramiento a familias y profesionales sobre la atencion e intervencion a edades tempranas de los niños. Desarrollo. Se proporciona una revision actualizada de los procedimientos de deteccion precoz y de atencion temprana en el autismo, reflejando los aspectos mas relevantes que se deducen de las experiencias y estudios llevados a cabo hasta el momento. Conclusiones. Tras la revision realizada sobre las experiencias de deteccion precoz de autismo, se obtiene un grupo de consideraciones importantes para realizar analisis criticos de programas de cribado en marcha, asi como recomendaciones para experiencias futuras. La revision sobre los programas de atencion temprana proporciona una vision esperanzadora porque cada vez son mas frecuentes, sistematicos y metodologicamente mas apropiados los estudios sobre la eficacia de los programas de atencion temprana.

  13. Competitive sorption of atenolol, trimetoprim, carbamazepine and sulfamethoxazole in three soil types

    NASA Astrophysics Data System (ADS)

    Kočárek, Martin; Kodešová, Radka; Klement, Aleš; Golovko, Oksana; Fér, Miroslav; Nikodem, Antonín; Vondráčková, Lenka; Jakšík, Ondřej; Grabic, Roman

    2016-04-01

    Transport of human and veterinary pharmaceuticals in soils and consequent ground-water contamination are influenced by many factors, including compound sorption on soil particles and dissipation. Batch sorption experiment for 9 soils (3 soil types with 3 (Greyic Phaeozem on loess), 4 (Haplic Luvisol on loess) and 2 (Haplic Cambisol on gneiss) horizons) and mixture of 4 pharmaceuticals (atenolol, trimetoprim, carbamazepine and sulfamethoxazole) was performed to study competitive sorption of compounds in each soil sample. Sorption affinities and dissipation half-lives of all compounds in topsoils were previously studied by Kodešová et al. (2015 and 2016). Ten grams of dry soil was placed directly into the plastic centrifuge tubes and 20 ml of solution of a known pharmaceutical concentration was added. The same concentrations (0.5, 1, 2.5, 5 and 10 mg/l) were used for all compounds. Three replicates of each concentration were applied for each soil. Tube was shaken for 24 h using the shaking apparatus at 20 C. After shaking, the analyzed soil suspension was centrifuged for 10 min at 6,000 rotations per minute. The actual initial and final equilibrium pharmaceutical concentrations were measured using two-dimensional liquid chromatography-tandem mass spectrometry LC/LC-MS/MS using isotope dilution and internal standard methods. The pharmaceutical concentration adsorbed on soil particles was calculated using the initial and final (i.e. after incubation) pharmaceutical concentrations. The Freundlich equations were used to fit data points of the measured adsorption isotherms. In the case of carbamazepine (neutral form) and sulfamethoxazole (partly negatively charged) sorption affinity of compounds decrease with soil depth. On the other hand in the case of atenolol and trimethoprim (both positively charged) compound sorption affinity was not depth dependent. Data obtained for top soils were compared with sorption affinities for single compounds published by (Kodešová et

  14. A soil map of a large watershed in China: applying digital soil mapping in a data sparse region

    NASA Astrophysics Data System (ADS)

    Barthold, F.; Blank, B.; Wiesmeier, M.; Breuer, L.; Frede, H.-G.

    2009-04-01

    , can be classified as Kastanozems. Besides the Kastanozems, Regosols are most common at the sand dune sites as well as at sites that are defined as bare soil which are characterized by little or no vegetation. Gleysols are mostly found at sites in the vicinity of the Xilin river, which are connected to the groundwater. They can also be found in small valleys or depressions where sub-surface waters from neighboring areas collect. The richest soils are found in mountain meadow areas. Pedogenetic conditions here are most favorable and lead to the formation of Chernozems with deep humic Ah horizons. Other soil types that occur in the study area are Arenosols, Calcisols, Cambisol and Phaeozems. In addition, soil taxonomic distance is implemented into the decision tree procedure as a measure of classification error. The results of incorporating taxonomic distance as a loss function in the decision tree will be compared with the standard application of the decision tree.

  15. Environmental Controls of Soil Organic Carbon in Soils Across Amazonia

    NASA Astrophysics Data System (ADS)

    Quesada, Carlos Alberto; Paz, Claudia; Phillips, Oliver; Nonato Araujo Filho, Raimundo; Lloyd, Jon

    2015-04-01

    (kaolinitic) and thus the clay plus silt fraction was the best correlate for SOC but with crystalline iron oxides (dithionite-citrate minus ammonium oxalate - oxalic acid extractable iron) being also correlated to SOC in these soils (R2 = 0.74). Most of SOC in these soils was found on the clay+silt fraction and in stable, clay rich aggregates. However, SOC of high activity clays and other less weathered soils such as Alisols, Cambisols and Plinthosols showed no correlation with particle size or iron oxides, being mostly stabilized by aluminium complexes. We found SOC of these soils to be better explained by a three way interaction among soil pH, carbon quality and dithionite-citrate extractable Al (R2 = 0.85). Consistent with this observation, SOC in the less weathered soils was mostly found in the colloidal fraction (75%). SOC of Podzols and Arenosols on the other hand had only a small but significant influence from their clay plus silt fraction (R2 = 0.31), with particulate organic matter accounting for most of its SOC.

  16. Soils derived from Pieniny andesite, Wdżar hill, Outer Carpathians (Poland)

    NASA Astrophysics Data System (ADS)

    Kajdas, Bartlomiej; Zaleski, Tomasz; Mazurek, Ryszard

    2016-04-01

    Tertiary andesite occurs in only few places in Polish part of the Outer Carpatians. The biggest andesitic body is observed at the Wdżar hill (676 m a.s.l), SE from Kluszkowce village. To the beginning of the 1970s active quarry were located at the hill slope, and from the end of 1990s Wdżar is used as a ski resort. Because Wdżar is the culmination protruding over sandstones and shales of Magura Unit of Outer Carpatians, it gives opportunity to investigate soils derived directly from the andesite. Primary, unaltered andesite contain mainly plagioclase (An28-62), amphibole (hornblende group), clinopiroxene (pigeonite group) and Fe-Ti oxides (Michalik et al., 2004). Quartz in those type of rocks is absent. Andesites from Pieniny Mts. contain low amount of silica (ca. 52-55% wt. in fresh and about 62% wt. in hydrothermally altered rocks), and high amount of CaO (5,5-9,2% wt.) and MgO (0,8-5,5% wt.) (Nejbert et al., 2012). Soils cover on Wdżar hill represents different stages of soil development. Shallow, ca. 15 cm deep, Eutric Leptosols and deeper, 60 cm and over 200 cm deep, Eutric Skeleti Cambisols (Colluvic, Humic) were distinguished. There are significant differences both between the soil groups as well as inside them. Investigated soils have sandy loam, loam and silt loam texture. Surface, organic horizons show acid reaction, but cambic and parent material horizons show neutral reaction. Cation exchange capacity ranges between 526.9 and 298.2 mmol(+)ṡkg-1 in humus horizons and between 451.4 and 225.8 mmol(+)ṡkg-1in cambic and parent material horizons. The amount of exchangeable Ca2+ ranges between 386.8 and 175.8 mmol(+)ṡkg-1 and is about 6 times higher than sum of Mg2+, Na+ and K+ in the soil horizon. Despite of the high amount of Ca2+, there were no active carbonates in investigated soil. The soils, that are developed from the andesite, usualy contain high amount of clays and very low amount of primary quartz. Andesite from Wdżar reveals minor degree

  17. Late Pleistocene to early Holocene aeolian and flash-flood sedimentation and soil formation in a small hilly catchment in SW-Germany (Palatinate forest)

    NASA Astrophysics Data System (ADS)

    Dotterweich, M.; Kühn, P.; Tolksdorf, J. F.; Müller, S.; Nelle, O.

    2012-04-01

    . The layers are overlain by very clear visible wavy and frequently distributed clay-illuviation bands typical for a Luvisol. The upper meter looks duller and more homogenous which is typical for a Bv-horizion of a Cambisol. The embedded deposition shows structures in this sediment package that are typical for a flash-flood event. Records of soil erosion during this time period are sparse and it is generally assumed that sediments were fixed by forest vegetation. In contrast, these presented results indicate that the manipulation of forest vegetation by fire by sedentary Mesolithic hunter-gatherers created an open area and enabled soil erosion with a high geomorphological impact on a local scale. This geoarchive provides first time high resolution data on a natural (and anthropogenic) soil-sediment formation during the Late Pleistocene and Early Holocene in SW-Germany.

  18. Total and available phosphorus at the field scale after long-term manure application

    NASA Astrophysics Data System (ADS)

    Machado Siqueira, Glécio; da Silva Días, Rosane; Garcia Tomillo, Aitor; Vidal Vázquez, Eva

    2013-04-01

    Application of livestock manure to agricultural fields has been shown to increase crop growth and improve the soil capacity to hold water and nutrients. However, in agricultural areas with high cattle manure and/or slurry inputs over a period of several years, soil P can accumulate to levels in excess of crop needs. Phosphate overloading in soil has the potential to enrich surface runoff causing eutrophication of water bodies. The accelerated nutrient enrichment or eutrophication of surface water by runoff has become a significant environment problem in many developed countries. This is also the case in the Atlantic temperate humid region of Galicia, north-western of Spain. Various extraction methods are used to measure available P in soils. Differences in soil phosphorus (P) concentrations measured by various techniques may have implications for agronomic and environmental testing. The aims of this study were: 1) to compare available and total P concentrations measured by various methods and 2) to assess variability of excessive P accumulated on a field with a long-term history of manure application. Forty soil samples were taken at the 0-30 cm depth on a 6 ha field with mean slope of 2%, located in Castro de Ribeira de Lea, Lugo province, Spain. The study soil had hydromorphic features and was classified as a gleyic Cambisol. Available soil P was extracted by anion-exchange resin (AER) and by Mehlich 3 (M3). Moreover, two determination methods of P contents extracted by Mehlich 3, namely molybdic acid colorimetric standard procedure (M3-COL) and inductively coupled plasma emission spectroscopy or ICP-MS (M3-ICP) were compared. Total P was determined after extraction with nitric acid combined with microwave digestion, following the USEPA method 3051, and determined by ICP-MS. Mean values for AER-P, M3-COL-P, M3-ICP-P and total-P were 160.0, 397.6, 498.2 and 1080.9 mg kg-1, respectively. Therefore a marked accumulation of P in the top soil layer occurred following

  19. Dissolved organic carbon (DOC) in soil extracts investigated by FT-ICR-MS

    NASA Astrophysics Data System (ADS)

    Hofmann, D.; Steffen, D.; Jablonowski, N. D.; Burauel, P.

    2012-04-01

    Soil drying and rewetting usually increases the release of xenobiotics like pesticides present in agricultural soils. Besides the effect on the release of two aged 14C-labeled pesticide residues we focus on the characterisation of simultaneously remobilized dissolved organic carbon (DOC) to gain new insights into structure and stability aspects of soil organic carbon fractions. The test soil (gleyic cambisol; Corg 1.2%, pH 7.2) was obtained from the upper soil layer of two individual outdoor lysimeter studies containing either environmentally long-term aged 14C residues of the herbicide ethidimuron (0-10 cm depth; time of aging: 9 years) or methabenzthiazuron (0-30 cm depth; time of aging: 17 years). Soil samples (10 g dry soil equivalents) were (A=dry/wet) previously dried (45°C) or (B=wet/wet) directly mixed with pure water (1+2, w:w), shaken (150 rpm, 1 h), and centrifuged (2000 g). This extraction procedure was repeated several individual times, for both setups. The first three individual extractions, respectively were used for further investigations. Salt was removed from samples prior analysis because of a possible quench effect in the electrospray (ESI) source by solid phase extraction (SPE) with Chromabond C18 Hydra-cartridges (Macherey-Nagel) and methanol as backextraction solvent. The so preconcentrated and desalted samples were introduced by flow injection analysis (FIA) in a fourier transform ion cyclotron resonance mass spectrometer (FT-ICR-MS), equipped with an ESI source and a 7 T supra-conducting magnet (LTQ-FT Ultra, ThermoFisher Scientific). This technique is the key technique for complex natural systems attributed by their outstanding mass resolution (used 400.000 at m/z 400 Da) and mass accuracy (≤ 1ppm) by simultaneously providing molecular level details of thousands of compounds and was successful applied for the investigations of natural organic matter (NOM) different sources like marine and surface water, soil, sediment, bog and crude oil

  20. Presenting the 3rd edition of WRB

    NASA Astrophysics Data System (ADS)

    Schad, Peter

    2014-05-01

    The third edition of the international soil classification system "World Reference Base for Soil Resources" (WRB) will be presented during der 20th World Congress of Soil Science, Jeju, Korea, June 9-12. The second edition was published in 2006 and the first in 1998, which, in turn, was based on the Legends of the FAO Soil Map of the World. Now, after eight years of experience with the second edition, time was due for a revision. The major changes are: 1. The second edition had two different qualifier sequences for naming soils (IUSS Working Group WRB, 2006, update 2007) and for creating map legends (Guidelines for creating small-scale map legends using the WRB; IUSS Working Group WRB, 2010). The third edition has one sequence for both. The qualifiers for every Reference Soil Group are subdivided into a small number of main qualifiers that are ranked and a larger number of additional qualifiers that are not ranked and given in an alphabetical order. The name of a pedon must comprise all applying qualifiers. The name of a map unit comprises a specified small number of main qualifiers, depending on scale, whereas all other qualifiers are optional. 2. For some soils, problems have been reported. Albeluvisols are difficult to detect in the field and cover only small surfaces. They have been replaced by Retisols, which have a broader definition that is easier to identify in the field. 3. The use of some diagnostics was difficult. Examples are: The argic horizon had too low limit values, so we had much more soils with argic horizons than justified. The definitions of the cambic horizon and the gleyic and stagnic properties were not precise enough. Organic material, mollic and umbric horizons had an unnecessary complicated definition. 4. Some changes in the key to the Reference Soil Groups seemed to be justified. Fluvisols were moved further down, Durisols and Gypsisols switched their position, also Arenosols and Cambisols. The soils with an argic horizon were brought

  1. Past soil erosion history recorded by lake sediments in mountain areas (north and south French Alps): complex interactions with climatic and human activities

    NASA Astrophysics Data System (ADS)

    Giguet-Covex, C.; Poulenard, J.; Arnaud, F.; Disnar, J.-R.; Sabatier, P.; Wilhelm, B.; Jouffroy-Bapicot, I.; Rey, P.-J.; David, F.; Malet, E.

    2012-04-01

    , at 5450 cal. BP affects both leptosols and developped soil surface horizons (podzols. It is thus interpreted as mainly reflecting the climatic reversal toward colder and wetter conditions, known during this period. Likewise, during the end of Iron Age and the begin of Roman period, the most important erosion phase of the Holocene firstly affects developed soil (cambisol)surface horizons (during 300 years) and then attacks the deepest horizons (during 250 years). This suggest an intensification of grazing activity. Our interpretations are also supported by palynological and archaeological data. The preliminary results of Lake Lauzanier show high terrigenous inputs during the Little Ice Age (LIA), probably due to wetter climatic conditions, as it is observed for Lake Anterne. However, during the last 1000 years, the most important phase of erosion is recorded just after the LIA, between AD 1900 and Ad 1960. This phase is interpreted as the result of intensification of human activities (probably grazing) affecting the soil stability in the catchment.

  2. Assessing soil erosion at landscape level: A step forward in the up-scaling of 137Cs measurements through the use of in-situ lanthanum bromide scintillator

    NASA Astrophysics Data System (ADS)

    Gonsalves, Basil C.; Darby, Iain G.; Toloza, Arsenio; Mabit, Lionel; Kaiser, Ralf B.; Dercon, Gerd

    2014-05-01

    Measuring Fallout Radionuclides (FRN), in particular 137Cs, is a well-established method to estimate soil erosion and deposition in agricultural landscapes. While extremely sensitive, laboratory based gamma-ray spectrometry requires careful handling and preparation of measurement samples with a lengthy measuring time (~1 day), In-situ gamma-ray spectrometry can give near instantaneous results, allowing prompt decisions to be made and identification of critical spots of soil erosion, while the equipment is in the field. The aim of this investigation was to compare the precision of the in-situ FRN measurements, made by a cost-effective lanthanum bromide (LaBr3 (Ce)) scintillation detector of 137Cs against those from conventional (high-purity germanium HPGe detector) but laborious laboratory based gamma-ray spectrometry for assessing soil erosion. As preliminary test, five cores of a gleyic Cambisol - per increments of 5 cm until 1 m depth - were collected at the experimental research station of the Austrian Agency for Health and Food Safety located in Grabenegg 130 km west of Vienna. Three soil cores were sampled at the study site and, in the vicinity of this experimental site, two additional cores were collected at two different undisturbed reference sites. Laboratory gamma analyses were carried out during 50 000 seconds using a HPGe coaxial detector. The gamma measurements performed at the laboratory confirmed the undisturbed status of the two selected reference sites (i.e. exponential decrease with depth of the 137Cs content). Using the surface area of the sampling tool, the 137Cs areal activities of the cores sampled in the study site have been established at 2134±465 Bq m-2, 1835±356 Bq m-2 and 2553±340 Bq m-2, and, for the two reference sites at 3221±444 Bq m-2 and 3946±527 Bq m-2. At the same location and prior to collect the five soil cores, in-situ measurements using a lanthanum bromide (LaBr3 (Ce)) scintillator were performed. The detector was placed

  3. Black Nitrogen or Plant-Derived Organic Nitrogen - which Form is More Efficiently Sequestered in Soils?

    NASA Astrophysics Data System (ADS)

    López-Martín, María; Velasco-Molina, Marta; Knicker, Heike

    2014-05-01

    Input of charcoal after forest fires can lead to considerable changes of the quality and quantity of organic matter in soils (SOM). This affects not only its organic C pool but also shifts its organic N composition from peptideous to N-heterocyclic structures (Knicker et al., 1996). In the present study we sought to understand how this alteration is affecting the N availability in fire affected soils. Therefore, we performed a medium-term pot experiment in which grass material (Lolium perenne) was grown on soil material (Cambisols) of a fire-affected and a fire-unaffected forest. The soils were topped with mixtures of ground fresh grass residues and KNO3 or charred grass material (pyrogenic organic matter; PyOM) with KNO3. Here, either the organic N or the inorganic N was isotopically enriched with 15N. Following the 15N concentration in the soil matrix and the growing plants as a function of incubation time (up to 16 months) by isotopic ratio mass spectrometry allowed us to indentify which N-source is most efficiently stabilized and how PyOM is affecting this process. Preliminary data indicated that only after the germination of the seeds, the concentration of the added inorganic 15N in the soil decreased considerably most likely due to its uptake by the growing plants but also due to N-losses by leaching and volatilization. Additional addition of plant residues or PyOM had no major effect on this behavior. Covering the soil with 15N-grass residues which simulates a litter layer led to a slow increase of the 15N concentration in the mineral soil during the first month. This is best explained by the ongoing incorporation of the litter into the soil matrix. After that a small decrease was observed, showing that the organic N was only slowly mobilized. Addition of 15N-PyOM showed a comparable behavior but with 15N concentration in the soil corresponding to twice of those of the pots amended with 15N-grass residues. After that the 15N concentrations decrease quickly

  4. Agricultural machineries wheeling and soil qualities mapping in climatic changes conditions

    NASA Astrophysics Data System (ADS)

    Bergonzoli, S.; Servadio, P.

    2012-04-01

    As argued in the Fourth Assessment Report of the UN International Panel on Climate Change (IPCC) published in 2007 the global climate is changing and will continue to change in the near future. Due to the changing in time distribution and intensity of rainfall, the available time to carry out soil tillage operations, seedbed preparation and fertilizers distribution is becoming shorter. These issues are worsened by soil compaction that is one of the major problems facing modern agriculture. Soil compaction impedes infiltration of rainfall, so the increasing scale of mechanization might well be responsible for greater runoff, soil loss by water erosion and water-logging. Overuse of machinery, intensive cropping, short crop rotations, intensive grazing and inappropriate soil management leads to compaction. The objective of this research was to study the compacting effect of two wheeled tractors fitted with different type of tires during fertilizing operations with soil water content over field capacity. Field tests were carried out in a farm near Rome (41°52'502'' Latitude (N); 12°12'866" Longitude (E)) in March 2010 on a clay soil (Vertic Cambisol) during wheat fertilizing. One tractor was fitted with very narrow and high aspect ratio tires with mounted broadcaster coded (WTN), the other tractor was equipped with extra large and low aspect ratio tires with trailed broadcaster for a total of four axles coded (WTEL). Immediately after fertilising operations, such effects have been quantified through spatial variation of some soil parameters: soil water content, soil penetration resistance (CI) and soil shear strength (SS). Soil samplings have been carried out on the tracks left by the tractors and on soil not interested by the passage (control). To monitor all tractors passes across the field and to compute the total area covered by tractors tires a DGPS receiver was placed into the tractors; to map soil parameters studied, both on tracks left by the tractors passes

  5. Former charcoal kiln sites where forest was cleared for cultivation: a case study of old biochar in cropland

    NASA Astrophysics Data System (ADS)

    Hardy, Brieuc; Dufey, Joseph E.; Cornelis, Jean-Thomas

    2014-05-01

    The use of biochar as a soil amendment is being increasingly investigated as a win-win solution for mitigating the anthropic CO2 emissions and improving soil fertility. However, data on the long term impact of chars on soil properties are scarce, although they are crucial for better understanding the implications of large scale application of highly persistent biochars to soil. In Wallonia (Belgium), old charcoal kilns are found in most of the area that was forested in the late 18th century. Since then, a non-negligible part of the forest has been cleared for cultivation. Today, old charcoal-making platforms can be seen on bare soils as circular or elliptic black spots due to charcoal enrichment. In order to assess the long-term (>200 years) effects of biochar on soil chemical properties, seventeen kiln sites were chosen in several cropland areas of Wallonia on loessic luvisols (14) and loamy cambisols (3). Composite samples were taken in the ploughing layer (0 - 25 cm) and the underlying horizon (35 - 50 cm) in and out the kiln sites. The pH, total carbon (C) and nitrogen (N) contents, oxidizable carbon (CW&B), available phosphorus (Pav), cation exchange capacity at pH 7 (CEC), exchangeable cations content (Ca++, Mg++, K+, Na+) and loss on ignition at 550°C (LI550) were measured. In order to assess the impact of cultivation on charcoal aging, we also sampled four kiln sites on loessic luvisols under forest. Here, we show that charcoal, diluted laterally by successive tillage, acts as a carbon surplus in the topsoil layer of the black spots. The charcoal-enriched horizon is characterized by higher CEC, C/N and C/LI550 ratio compared to the reference soil. Cultivation of former forest soils accelerates charcoal aging, likely due to a combined effect of mechanical (tillage splits charcoal fragments in smaller pieces and increases soil aeration) and biological actions (promoted by improved trophic conditions due to application of amendments and fertilizers over many

  6. Conservation tillage versus conventional tillage on carbon stock in a Mediterranean dehesa (southern Spain)

    NASA Astrophysics Data System (ADS)

    Parras-Alcántara, Luis; Lozano-García, Beatriz

    2014-05-01

    Understanding soil dynamics is essential for making appropriate land management decisions, as soils can affect the carbon content from the atmosphere, emitting large quantities of CO2 or storing carbon. This property is essential for climate change mitigation strategies as agriculture and forestry soil management can affect the carbon cycle. The dehesa is a Mediterranean silvopastoral system formed by grasslands with scattered oaks (Quercus ilex or Q. suber). The dehesa is a pasture where the herbaceous layer is comprised of either cultivated cereals such as oat, barley and wheat or native vegetation dominated by annual species, which are used as grazing resources. In addition, the dehesa is a practice dedicated to the combined production of Iberian swine, sheep, fuel wood, coal and cork, as well as hunting. The dehesa is characterized by the preservation of forest oaks. In this work, we compared two management practices such as organic farming (OF) and conventional tillage (CT) on soil organic carbon stocks (SOC-S) in Cambisols (CM) and Leptosols (LP), and we analyzed the quality of these soils based on stratification ratio (SR) in a Mediterranean dehesa. MATERIAL AND METHODS An analysis of 85 soil profiles was performed in 2009 in Los Pedroches Valley (Cordoba, southern Spain). Two soil management practices were selected: OF (isolated trees of variable densities —15-25— trees ha-1, mostly holm and cork oaks, and patches of shrubs — cistaceae, fabaceae and lamiaceae— with a herbaceous pasture layer mostly composed of therophytic species and livestock are introduced to provide organic fertilizer to the soil, without ploughing and animal manure from the farms may be incorporated) for 20 years and CT (similar to OF, with ploughing —annual passes with a disc harrow and/or cultivator— is aimed at growing grain for livestock or at clearing the encroaching shrubs) in CM and LP. The dehesas studied were silvopastoral systems without cropping. Soil properties

  7. Agricultural use of soil, consequences in soil organic matter and hydraulic conductivity compared with natural vegetation in central Spain

    NASA Astrophysics Data System (ADS)

    Vega, Verónica; Carral, Pilar; Alvarez, Ana Maria; Marques, Maria Jose

    2014-05-01

    When ecosystems are under pressure due to high temperatures and water scarcity, the use of land for agriculture can be a handicap for soil and water conservation. The interactions between plants and soils are site-specific. This study provides information about the influence of the preence vs. The absence of vegetation on soil in a semi-arid area of the sout-east of Madrid (Spain, in the Tagus River basin. In this area soil materials are developed over a calcareous-evaporitic lithology. Soils can be classified as Calcisols, having horizons of accumulation with powdered limestone and irregular nodules of calcium carbonate. They can be defined as Haplic Cambisols and Leptic Calcisols (WRB 2006-FAO). The area is mainly used for rainfed agriculture, olive groves, vineyards and cereals. There are some patches of bushes (Quercus sp.) and grasses (Stipa tenacissima L.) although only found on the top of the hills. This study analyses the differences found in soils having three different covers: Quercus coccifera, Stipa tenacissima and lack of vegetation. This last condition was found in the areas between cultivated olive trees. Soil organic matter, porosity and hydraulic conductivity are key properties of soil to understand its ability to adapt to climate or land use changes. In order to measure the influence of different soil covers, four replicates of soil were sampled in each condition at two soil depth, (0-10 cm and 10-20 cm). Hydraulic conductivity was measured in each soil condition and replicate using a Mini-disk® infiltrometer. There were no differences between the two depths sampled. Similarly, there were no changes in electric conductivity (average 0.1±0.03 dS m-1); pH (8.7±0.2) or calcium carbonate content (43±20 %). Nevertheless, significant differences (p>0.001) were found in soil organic matter. The maximum was found in soils under Quercus (4.7±0.5 %), followed by Stipa (2.2±1.1 %). The soil without vegetation in the areas between olive trees had only 0

  8. Temporal variation of aqueous-extractable Ca, Mg and K in acidified forest mountainous soils under different vegetation cover

    NASA Astrophysics Data System (ADS)

    Tejnecky, V.; Bradová, M.; Boruvka, L.; Vasat, R.; Nemecek, K.; Ash, C.; Sebek, O.; Rejzek, J.; Drabek, O.

    2012-12-01

    Acidification of forest soils is a natural degradation process which can be significantly enhanced by anthropogenic activities. Inputs of basic cations (BC - Ca, Mg and K) via precipitation, litter and soil organic matter decomposition and also via inter-soil weathering may partially mitigate the consequences of this degradation process. The aim of this study is to assess the temporal variation of aqueous-extractable Ca, Mg and K in acidified forest mountainous soils under different vegetation cover. The Jizera Mountains region (Czech Republic, northern Bohemia) was chosen as a representative soil mountainous ecosystem strongly affected by acidification. Soil and precipitation samples were collected at monthly basis from April till October/ November during the years 2009-2011. Study spots were delimited under two contrasting vegetation covers - beech and spruce monoculture. Prevailing soil types were classified as Alumic Cambisols under beech and Entic Podzols under spruce stands (according to FAO classification). Soil samples were collected from surface fermentation (F) and humified (H) organic horizons and subsurface B horizons (cambic or spodic). The collected soil samples were analyzed immediately under laboratory condition in a "fresh" state. Unsieved fresh samples were extracted by deionised water. The content of main elements (Ca, Mg, K, Al and Fe) was determined by ICP-OES. The content of major anions (SO42-, NO3-, Cl- and F-) was determined by ion-exchange chromatography (IC). Content of major anions and main elements were determined in the precipitation samples (throughfall, stemflow and bulk) as well. Besides computing the basic statistical parameters (mean, median, variance, maximum, minimum, etc.) we also employed other statistical methods such as T-test and ANOVA to assess the differences between beech and spruce vegetation spots. To carry out the temporal variability in the data we used the time series analysis and short-term forecasting by Holt

  9. Applicability and limitations of enzyme addition assays for the characterisation of soil organic phosphorus across a range of soil types

    NASA Astrophysics Data System (ADS)

    Jarosch, Klaus; Doolette, Ashlea; Smernik, Ronald; Frossard, Emmanuel; Bünemann, Else K.

    2014-05-01

    Solution 31P NMR spectroscopy is a powerful tool for the characterisation and quantification of organic P classes in soil. Potential limitations are due to costs, equipment accessibility and the requirement of relatively large amounts of sample. A recent alternative approach for the quantification of specific organic P classes is the use of substrate-specific phosphohydrolase enzymes which cleave the inorganic orthophosphate from the organic moiety. The released orthophosphate is detectable by colorimetry. Conclusions about the hydrolysed class of organic P can be made based on the comparison of inorganic P concentrations in enzymatically treated and untreated samples. The aim of this study was to test the applicability of enzyme addition assays for the characterisation of organic P classes on a) NaOH-EDTA extracts, b) soil:water filtrates (0.2 μm) and c) soil:water suspensions. The organic P classes in NaOH-EDTA extracts were also determined by 31P NMR spectroscopy, enabling a comparison between methods. Ten topsoil samples from four continents (five cambisols, two ferralsols, two luvisols and one lixisol) with varying total P content (83 - 1,1560 mg kg-1), pHH2O (4.2 - 8.0) and land management (grassland or cropped land) were analysed. Four different classes of organic P were determined by the enzyme addition assay: 1) monoester like-P (by an acid phosphatase known to hydrolyse simple monoesters, pyrophosphate and ATP), 2) DNA-like P (by a nuclease in combination with an acid phosphatase), 3) inositol phosphate-like P (by a phytase known to hydrolyse all monoester like-P plus myo-inositol hexakisphosphate and scyllo-inositol hexakisphosphate) and 4) enzyme stable-P (enzymatically not hydrolysed organic P forms). In the ten topsoil samples, NaOH-EDTA-extractable organic P ranged from 6 - 1,115 mg P kg-1 soil. Of this, 33 - 92 % was enzyme labile, with inositol phosphate-like P being the largest organic P class in most soils (15 - 51%), followed by monoester

  10. Impact of cattle grazing on soil and vegetation - a case study in a mountainous region of Austria

    NASA Astrophysics Data System (ADS)

    Bohner, Andreas; Foldal, Cecilie; Jandl, Robert

    2015-04-01

    In mountainous regions of Austria and of many other European countries, climate change may cause a further intensification of grassland management. Therefore, the effects of intensive cattle grazing on selected soil chemical and physical properties, above- and below-ground phytomass, forage quality, plant species composition and plant species richness at the scale of a representative paddock in a mountainous region of Austria were investigated. At the study site (Styrian Enns valley; 675 m a.s.l.), climate is relatively cool and humid, with a mean annual air temperature of 6.7°C and a mean annual precipitation of 970 mm, of which 66% falls during the vegetation period (April-October). The soil is a deep, base-rich Cambisol with a loamy sand texture. The paddock investigated has a total area of about 2 ha and had been grazed by dairy cows (Brown Swiss) five times per grazing season. The stocking density was 4 cows ha-1 during 180 days from early May to the end of October with a grazing time of about 8 hours per day. The strip grazed permanent pasture was manured annually for a long time, mostly with cattle slurry. Vegetation surveys were carried out using the method of Braun-Blanquet. Above- and below-ground phytomass, forage quality and mineral element concentration in the harvestable above-ground plant biomass were determined by using standard methods. During the grazing season surface soil samples (0-10 cm depth) for chemical analyses were collected before each grazing period (5 analyses of composite samples per site). At the beginning and the end of the grazing season also soil samples for physical analyses were taken from the topsoil (0-15 cm depth). Heavy cattle treading led to a substantial soil compaction especially in the 5-10 cm layer and to a deterioration of topsoil structure. The porous crumb structure was replaced by a compact platy structure. The topsoil was enriched with nutrients (mainly nitrogen, potassium, phosphorus and boron). The degree of

  11. Mercury in forest ecosystems near chlor-alkali plant in the Czech republic

    NASA Astrophysics Data System (ADS)

    Šimeček, Martin; Navratil, Tomas; Rohovec, Jan

    2016-04-01

    A mercury electrolysis chlor-alkali plant has been operating in Neratovice, the central Czech Republic since year 1948. We focused on the assessment of mercury contamination in the plant surroundings. To assess the contamination extent we sampled organic and mineral soils, bedrock, bark, needles and tree rings from several forest sites with variable distance from plant. The soils were predominately arenic cambisol and the vegetation cover composed of mixed to coniferous forests (majorly Pinus sylvestris). At all the sites, the highest concentrations occurred in the organic rich O horizons of the forest soils. The Hg concentrations increased from Oi horizon (up to 252 μg/kg) with fresh organic matter, through Oe horizons (up to 617 μg/kg) to the Oa horizons (up to 813 μg/kg) with relatively highly decomposed organic matter. The Hg concentrations in mineral soil were significantly lower in range from 3 to 44 μg/kg. Sandstone bedrock contained low Hg concentrations from 2.7 to 4.7 μg/kg. The difference between the high Hg in organic and low Hg in mineral horizons results from order of magnitude different content of soil organic matter. In the same time low Hg in mineral soil indicates low level of Hg migration down the soil profile. Apart from the simple comparison of Hg concentrations, insight into the patterns of soil Hg distribution can be gained by examining the stoichiometric ratios of Hg to C. Soil Hg/C should be greater in areas with greater atmospheric Hg deposition. O horizons of sites closer to plant up to 4.5 km exhibited elevated Hg/C ratios (2.0 - 2.2 μg/g) with respect to those at more distant sites (0.7 - 0.9 μg/g). Values of mineral soil Hg/C ratios varied irrespective to the distance from the plant. Organic soil Hg pool decreased from 13.6 mg/m2 in distance of 1.9 km from the plant to 2.6 mg/m2 in distance of 9 km. But the mineral soil Hg pool ranging from 7.6 to 12.3 mg/m2 exhibited no trend with distance. The polluted sites up to 2.5 km from

  12. Differences on soil organic carbon stock estimation according to sampling type in Mediterranean areas

    NASA Astrophysics Data System (ADS)

    Parras-Alcántara, Luis; Lozano-García, Beatriz

    2016-04-01

    Soil organic carbon (SOC) is an important part of the global carbon (C) cycle. In addition, SOC is a soil property subject to changes and highly variable in space and time. Consequently, the scientific community is researching the fate of the organic carbon in the ecosystems. In this line, soil organic matter configuration plays an important role in the Soil System (Parras-Alcántara and Lozano García, 2014). Internationally it is known that soil C sequestration is a strategy to mitigate climate change. In this sense, many soil researchers have studied this parameter (SOC). However, many of these studies were carried out arbitrarily using entire soil profiles (ESP) by pedogenetic horizons or soil control sections (SCS) (edaphic controls to different thickness). As a result, the indiscriminate use of both methodologies implies differences with respect to SOC stock (SOCS) quantification. This scenario has been indicated and warned for different researchers (Parras-Alcántara et al., 2015a; Parras-Alcántara et al., 2015b). This research sought to analyze the SOC stock (SOCS) variability using both methods (ESP and SCS) in the Cardeña and Montoro Natural Park (Spain). This nature reserve is a forested area with 385 km2 in southern Spain. Thirty-seven sampling points were selected in the study zone. Each sampling point was analyzed in two different ways, as ESP (by horizons) and as SCS with different depth increments (0-25, 25-50, 50-75 and 75-100 cm). The major goal of this research was to study the SOCS variability at regional scale. The studied soils were classified as Phaeozems, Cambisols, Regosols and Leptosols. The results obtained show an overestimation of SOCS when SCS sampling approach is used compared to ESP. This supports that methodology selection is very important to SOCS quantification. This research is an assessment for modeling SOCS at the regional level in Mediterranean natural areas. References Parras-Alcántara, L., Lozano-García, B., 2014

  13. Origin of enormous trace metal enrichments in weathering mantles of Jurassic carbonates: evidence from Sr, Nd and Pb isotopes

    NASA Astrophysics Data System (ADS)

    Hissler, C.; Stille, P.; Juilleret, J.; Iffly, J.; Perrone, T.; Morvan, G.

    2013-12-01

    Weathering mantels are widespread worldwide and include lateritic, sandy and kaolinite-rich saprolites and residuals of partially dissolved carbonate 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 content of associated trace elements in this type of weathering mantle. For instance, these enrichments can represent about five times the content of the underlying Bajocian to Oxfordian limestone/marl complexes, which have been relatively poorly studied compared to weathering mantle developed on magmatic bedrocks. 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 (saprolite, Bajocian silty marls and limestones, atmospheric particles deposition...). Of special interest has also been the origin of trace metals and the processes causing their enrichments. Especially Rare Earth Element (REE) distribution patterns and Sr, Nd and Pb isotope ratios 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 shall help to identify mobile phases in the soil system. This may inform on the stability of trace elements and especially on their behaviour in these Fe-enriched carbonate systems. Trace metal migration and enrichments were studied on a cambisol developing on an underlying Jurassic limestone. The base is strongly enriched among others in rare earth elements (ΣREE: 2640ppm) or redox-sensitive elements such as Fe (44 wt.%), V (920ppm), Cr (700ppm), Zn (550ppm), As (260ppm), Co (45ppm

  14. Comparision of ICP-OES and MP-AES in determing soil nutrients by Mechlich3 method

    NASA Astrophysics Data System (ADS)

    Tonutare, Tonu; Penu, Priit; Krebstein, Kadri; Rodima, Ako; Kolli, Raimo; Shanskiy, Merrit

    2014-05-01

    flammable (C2H2) gases, cylinder handling and the running costs of equipment are low. Detection limits of elements for MP-AES lays between the AAS and ICP ones. The objective of this study was to compare the results of soil analysis using two multielemental analytical methods - ICP-OES and MP-AES. In the experiment, different soil types with various texture, content of organic matter and pH were used. For the study soil samples of Albeluvisols, Leptosols, Cambisols, Regosols and Histosols were used . The plant available nutrients were estimated by Mehlich 3 extraction. The ICP-OES analysis were provided in the Estonian Agricultural Research Centre and MP-AES analysis in department of Soil Science and Agrochemistry at Estonian University of Life Sciences. The detection limits and limits of quantification of Ca, K, Mg and P in extracts are calculated and reported.

  15. Soil, vegetation and total organic carbon stock development in self-restoring abandoned vineyards

    NASA Astrophysics Data System (ADS)

    József Novák, Tibor; Incze, József; Spohn, Marie; Giani, Luise

    2016-04-01

    Abandoned vineyard's soil and vegetation development was studied on Tokaj Nagy-Hill, which is one of the traditional wine-producing regions of Hungary, it is declared as UNESCO World Heritage site as cultural landscape. Spatial distribution and pattern of vineyards were changing during the last several hundreds of years, therefore significant part of abandoned vineyards were subjected to long-term spontaneous secondary succession of vegetation and self-restoration of soils in absence of later cultivation. Two chronosequences of spontaneously regenerating vineyard abandonments, one on south (S-sequence) and one on southwest (SW-sequence) slope with differing times since their abandonment (193, 142, 101, 63, 39 and 14 years), were compiled and studied. The S-sequence was 25-35% sloped and strongly eroded, and the SW-sequence was 17-25% sloped and moderately eroded. The sites were investigated in respect of vegetation characteristics, soil physico-chemical characteristics, total organic carbon stocks (TOC stocks), accumulation rates of total organic carbon (TOC accumulation rates), and soil profiles, which were classified according to the World Reference Base (WRB) 2014. Vegetation development resulted in shrub-grassland mosaics, supplemented frequently by protected forb species and forest development at the earliest abandonment in S-sequence, and predominantly to forest vegetation in SW-sequence, where trees were only absent at the 63 and 14 years old abandonment sites. In all sites soils on level of reference groups according to WRB were classified, and Cambisols, Regosols, Calcisols, Leptosols, Chernozems and Phaeozems were found. Soils of the S-sequence show shallow remnants of loess cover with colluvic and redeposited soil materials containing 15-65% skeletal volcanic rock of weathering products coated by secondary calcium carbonates. The SW-sequence profiles are developed on deep loess or loess derivatives. The calcium-carbonate content was higher in profiles of

  16. The role of recharge zones, discharge zones, springs and tile drainage systems in peneplains of Central European highlands with regard to water quality generation processes

    NASA Astrophysics Data System (ADS)

    Dolezal, F.; Kvitek, T.

    2003-04-01

    Large areas of ploughed lands in old peneplains of Central Europe (such as the Bohemo-Moravian Highland) are located on flat tops of hills. Their soils, mostly Cambisols on weathered acid crystalline rocks (e.g., granite and gneiss) are permeable and shallow or medium-deep. These are the zones of groundwater recharge and it is through them that the local water-bearing formations (weathered rocks, colluvia and quaternary sediments in valleys) receive their portions of nitrate and other pollutants. The groundwater exfiltrates on the lower parts of slopes and in narrow valleys, creating dispersed springs and waterlogged areas. The latter were traditionally used, if at all, as forests or meadows. Since about 1960, many of the former meadows in foothill zones of Czech highlands have been drained by subsurface tile drainage systems and turned into arable lands. Field measurements in several small experimental catchments in this area proved that the water which is being discharged into the main stream either by small surface tributaries collecting water from subsurface drainage systems or by the subsurface drainage systems themselves reveals high concentrations of nitrate. Strong intraseasonal variation of water quality and the results of runoff separation suggest that the overall turnover of groundwater is fast. It is hypothesised that the redox status of the formerly waterlogged sites has been shifted toward the oxidation side due to drainage and tillage, rendering the removal of nitrogen from groundwater by denitrification less efficient. Hence, it is mainly the combination of diffuse pollution by nitrate in the recharge zones and the lack of opportunity for denitrification in the transitional and discharge zones which makes the stream water polluted. The ploughed lands in the recharge zones represent an established basis for local agriculture and cannot be set aside. Many of them have however been declared as vulnerable zones in terms of the nitrate pollution risk

  17. The Influence of Tree Species on Subsurface Stormflow at the Hillslope Scale

    NASA Astrophysics Data System (ADS)

    Jost, G.; Weiler, M.

    2006-12-01

    This study investigates the effect of Norway spruce (Picea abies (L.) Karst) and European beech (Fagus sylvatica L.), two very common tree species in Central Europe, on soil water storage and runoff response to precipitation. We postulate that on the same type of soil, spruce with its shallow rooting system leads to different soil water storage and runoff responses than the deep rooting beech. To test this hypothesis, we chose a beech and a spruce stand with comparable soil type, a stagnic cambisol with a stagnic layer in about 50 cm soil depth. In each of the two stands we sprinkled a hillslope of 6 m by 10 m with intensities of 100 mm/h and 60 mm/h for one hour each. Surface and shallow interflow as well as interflow in different soil depths was collected by inserted sheet metals and gutters in 10 cm, 30 cm and 60 cm soil depth. Soil water storage responses were measured by 48 multiplexed TDR sensors at each hillslope. TDR wave-guides (20 cm long) were installed in a 45° angle in 10 cm, 30 cm, 50 cm and 70 cm soil depth. Volumetric water content was measured in 6 minute intervals. Sprinkling experiments show that even at intensities of 100 mm/h all the applied water infiltrates, independent of the vegetation cover. The deeper soil horizons respond immediately to the applied precipitation. This vertical water flux response is larger under beech. Under spruce most of the water transport happens in the topsoil layers (upper 40 cm), whereas under beech the entire soil profile down to 80 cm soil depth reacts to sprinkling. Under spruce at intensities of 100 mm/h the whole pore space is almost filled. The larger pores in the topsoil under beech stemming from higher biogenic activity and in the subsoil from more intense rooting are still far from reaching their maximum capacity. High antecedent soil water content (around field capacity) still doesn't cause infiltration excess overland flow but the time that it takes for the soil water storage to drain to its initial

  18. Contact resistance problems applying ERT on low bulk density forested stony soils. Is there a solution?

    NASA Astrophysics Data System (ADS)

    Deraedt, Deborah; Touzé, Camille; Robert, Tanguy; Colinet, Gilles; Degré, Aurore; Garré, Sarah

    2015-04-01

    Electrical resistivity tomography (ERT) has often been put forward as a promising tool to quantify soil water and solute fluxes in a non-invasive way. In our experiment, we wanted to determine preferential flow processes along a forested hillslope using a saline tracer with ERT. The experiment was conducted in the Houille watershed, subcatchment of the Meuse located in the North of Belgian Ardennes (50° 1'52.6'N, 4° 53'22.5'E). The climate is continental but the soil under spruce (Picea abies (L.) Karst.) and Douglas fire stand (Pseudotsuga menziesii (Mirb.) Franco) remains quite dry (19% WVC in average) during the whole year. The soil is Cambisol and the parent rock is Devonian schist covered with variable thickness of silty loam soil. The soil density ranges from 1.13 to 1.87 g/cm3 on average. The stone content varies from 20 to 89% and the soil depth fluctuates between 70 and 130 cm. The ERT tests took place on June 1st 2012, April 1st, 2nd and 3rd 2014 and May 12th 2014. We used the Terrameter LS 12 channels (ABEM, Sweden) in 2012 test and the DAS-1 (Multi-Phase Technologies, United States) in 2014. Different electrode configurations and arrays were adopted for different dates (transect and grid arrays and Wenner - Schlumberger, Wenner alpha and dipole-dipole configurations). During all tests, we systematically faced technical problems, mainly related to bad electrode contact. The recorded data show values of contact resistance above 14873 Ω (our target value would be below 3000 Ω). Subsequently, we tried to improve the contact by predrilling the soil and pouring water in the electrode holes. The contact resistance improved to 14040 Ω as minimum. The same procedure with liquid mud was then tested to prevent quick percolation of the water from the electrode location. As a result, the lower contact resistance dropped to 11745 Ω. Finally, we applied about 25 litre of saline solution (CaCl2, 0.75g/L) homogeneously on the electrode grid. The minimum value of

  19. Hidden gully erosion - detection and characterization of piping systems using geomorphological and geophysical methods (GPR, ERT)

    NASA Astrophysics Data System (ADS)

    Bernatek-Jakiel, Anita; Kondracka, Marta

    2016-04-01

    The significance of piping in gully formation and hillslope hydrology has been discussed for many years. However, piping as a subsurface erosion caused by water flowing through the soil is still considered as one of the most difficult erosion processes to study, because it occurs below the soil surface and traces of piping become visible on the surface only when a pipe roof collapses, or a pipe inlet or a pipe outlet has been located. Detection of pipes and their complex characterization is still a methodological challenge. Therefore, this study aims at a better detection and characterization of piping systems in a mountainous area under a temperate climate using geomorphological mapping and geophysical methods (ground penetrating radar and electrical resistivity tomography). The survey was carried out in the Bereźnica Wyżna catchment, in the Bieszczady Mts. (Eastern Carpathians, Poland), where pipes develop in Cambisols at a depth ranging from ca 0.70 to 1.00 m. The geomorphological mapping was carried out in the in the whole catchment (2.96 km2), whereas the geophysical survey was limited to two zones (zone A - ca 32 x 82 m, zone B - ca 58 x 115 m). In this study a standard RAMAC GPR system (Malå GeoScience) with shielded 500 MHz antenna was used. The electrical resistivity tomography (ERT) was performed using electrical imaging system LUND with Terrameter SAS 4000 produced by company ABEM. The ERT and GPR data were interpreted in the RES2DINV (Geotomo Software) and RadExplorer software (DECO Geophysical Ltd) respectively. In total, 3 longitudinal and 26 transverse GPR profiles and five ERTs were performed. The used geophysical techniques are shown to be successful in identifying pipes tested in the pilot catchment. Pipes identified by GPR and ERT were verified by the surface indicators (i.e. lowering of surface above pipes). The GPR and ERT applications suggest that piping systems density is much greater than could be detected from surface observation alone

  20. Biochar contribution to soil pH buffer capacity

    NASA Astrophysics Data System (ADS)

    Tonutare, Tonu; Krebstein, Kadri; Utso, Maarius; Rodima, Ako; Kolli, Raimo; Shanskiy, Merrit

    2014-05-01

    Biochar as ecologically clean and stable form of carbon has complex of physical and chemical properties which make it a potentially powerful soil amendment (Mutezo, 2013). Therefore during the last decade the biochar application as soil amendment has been a matter for a great number of investigations. For the ecological viewpoint the trend of decreasing of soil organic matter in European agricultural land is a major problem. Society is faced with the task to find possibilities to stabilize or increase soil organic matter content in soil and quality. The availability of different functional groups (e.g. carboxylic, phenolic, acidic, alcoholic, amine, amide) allows soil organic matter to buffer over a wide range of soil pH values (Krull et al. 2004). Therefore the loss of soil organic matter also reduces cation exchange capacity resulting in lower nutrient retention (Kimetu et al. 2008). Biochar can retain elements in soil directly through the negative charge that develops on its surfaces, and this negative charge can buffer acidity in the soil. There are lack of investigations about the effect of biochar to soil pH buffering properties, The aim of our investigation was to investigate the changes in soil pH buffer capacity in a result of addition of carbonizated material to temperate region soils. In the experiment different kind of softwood biochars, activated carbon and different soil types with various organic matter and pH were used. The study soils were Albeluvisols, Leptosols, Cambisols, Regosols and Histosols . In the experiment the series of the soil: biochar mixtures with the biochar content 0 to 100% were used. The times of equiliberation between solid and liquid phase were from 1 to 168 hours. The suspension of soil: biochar mixtures was titrated with HCl solution. The titration curves were established and pH buffer capacities were calculated for the pH interval from 3.0 to 10.0. The results demonstrate the dependence of pH buffer capacity from soil type