WorldWideScience

Sample records for tetrachne dregei nees

  1. Genetic diversity and gene flow in the morphologically variable, rare endemics Begonia dregei and Begonia homonyma (Begoniaceae).

    Science.gov (United States)

    Matolweni, L O; Balkwill, K; McLellan, T

    2000-03-01

    Begonia dregei and B. homonyma (Begoniaceae), rare plants endemic to coastal forests of eastern South Africa, are two closely related species with high levels of variation among populations in the shape of leaves. Distribution of genetic variation and genetic relatedness were investigated in 12 populations of B. dregei and seven of B. homonyma using polyacrylamide gel electrophoresis. Twelve of the 15 enzyme loci examined were polymorphic, but only seven loci were polymorphic within at least one population. Genetic diversity measures indicated that the among-population gene differentiation represents >90% of the total genetic component in both species considered individually or combined. This indicated restricted gene flow, consistent with the limited dispersal abilities of Begonia generally and the ancient separation of isolated forest patches. Genetic distances among populations are much higher than usually found within species. Allozyme data provide no support for the recognition of B. dregei and B. homonyma as distinct species.

  2. Correlated evolution of leaf shape and trichomes in Begonia dregei (Begoniaceae).

    Science.gov (United States)

    McLellan, Tracy

    2005-10-01

    Structural features of leaves, including size, shape, and surfaces, vary greatly throughout the plant kingdom. In both functional and phylogenetic analyses of leaves, the various morphological aspects are often considered independently of each other, although it is likely that many combinations of features do not occur at random due to either functional constraint or genetic correlation. The distribution of variation in leaf morphology in the highly variable Begonia dregei species complex was examined in natural populations and in F(2) offspring from a cross between plants from two populations. Leaf shape was quantified using several morphometric measures, and trichomes on leaves were counted and measured. Correlations between leaf shape and the numbers and size of trichomes were examined. There were significant correlations between the shapes of leaves and the presence, number, and size of trichomes among populations and in hybrid plants. Deeply incised leaves had larger numbers of longer trichomes at the sinuses. Higher numbers of trichomes on upper leaf surfaces occurred together with trichomes at the petiole and on the abaxial surface. The potential for independent evolution of leaf shape and trichomes in this group is limited. Hypotheses to explain the correlated development of leaf shape and trichomes are discussed.

  3. Nanostructures for Electrical Energy Storage (NEES) EFRC

    Data.gov (United States)

    Federal Laboratory Consortium — The Nanostructures for Electrical Energy Storage (NEES) EFRC is a multi-institutional research center, one of 46 Energy Frontier Research Centers established by the...

  4. New alkaloids from Phoebe grandis (Nees) Merr.

    Science.gov (United States)

    Awang, Khalijah; Mukhtar, Mat Ropi; Hadi, A Hamid A; Litaudon, Marc; Latip, Jalifah; Abdullah, Noor Rain

    2006-05-20

    The alkaloidal extract of the leaves of Phoebe grandis (nees) merr. have provided two new minor alkaloids; phoebegrandine D (1), a proaporphine-tryptamine dimer, and phoebegrandine E (2), an indoloquinolizidine. This is the first report on the occurrence of an indoloquinolizidine in the Phoebe species. The crude extract also exhibited antiplasmodial activity (IC50<8 microg mL-1). The structures of the novel compounds were elucidated by spectroscopic methods, notably 2D NMR and HRMS.

  5. New compounds from Commiphora myrrha (Nees) Engl.

    Science.gov (United States)

    Ahmed, F; Ali, M; Singh, O

    2006-08-01

    Phytochemical investigation of Commiphora myrrha (Nees) Engl. has afforded six new compounds identified as cadina-3-en-15-ol (myrracadinol A) (1), 7, 8-seco-2, 5-dihydroxy-12-acetoxycalam-8-ene (myrracalamene A) (2), 7, 8-seco-2, 3, 5-hydroxy-12-acetoxycalame-8-ene (myrracalamene B) (3), 7, 8-seco-cadin-3, 8-dien-2beta, 12-diol (myrracadinol B) (4), 7, 8-seco-12-hydroxycalam-8-ene (myrracalamene C) (6), 7, 8-seco-cadin-3,7(12)-dien-5alpha,10alpha-diol (myrracadinol C) (7) along with a known compound tria-cont-1-ene (5). Their structures were elucidated on the basis of spectral and chemical analyses.

  6. NeeMDB: Convenient Database for Neem Secondary Metabolites

    OpenAIRE

    Hatti, Kaushik S; Muralitharan, Lakshmi; Hegde, Rajendra; Kush, Anil

    2014-01-01

    Indian Neem tree is known for its pesticidal and medicinal properties for centuries. Structure elucidation of large number of secondary metabolites responsible for its diverse properties has been achieved. However, this data is spread over various books, scientific reports and publications and difficult to access. We have compiled and stored structural details of neem metabolites in NeeMDB, a database which can be easily accessed, queried and downloaded. NeeMDB would be central in dissipating...

  7. NeeMDB: Convenient Database for Neem Secondary Metabolites.

    Science.gov (United States)

    Hatti, Kaushik S; Muralitharan, Lakshmi; Hegde, Rajendra; Kush, Anil

    2014-01-01

    Indian Neem tree is known for its pesticidal and medicinal properties for centuries. Structure elucidation of large number of secondary metabolites responsible for its diverse properties has been achieved. However, this data is spread over various books, scientific reports and publications and difficult to access. We have compiled and stored structural details of neem metabolites in NeeMDB, a database which can be easily accessed, queried and downloaded. NeeMDB would be central in dissipating structural information of neem secondary metabolites world over.

  8. Lignoids Isolated from Nectandra turbacensis (Kunth Nees (Lauraceae

    Directory of Open Access Journals (Sweden)

    Víctor Macías-Villamizar

    2016-03-01

    Full Text Available A new 7,8-secolignan, as well as seven known compounds; were isolated from Nectandra turbacensis (Kunth Nees (Lauraceae (leaves and root bark. These compounds were identified as, one secolignan, turbacenlignan A (1; four diaryldimethylbutane lignans: meso-monomethyl dihydroguaiaretic acid (2, threo-dihydroguaiaretic acid (3, schineolignin B (4, and austrobailignan-5 (5;and three 7,7' -epoxylignans: henricine (6 and the identifiable mixture of veraguensin (7 and galgravin (8. Compounds 1-8, were first isolated from Nectandra turbacensis (Kunth Nees (Lauraceae (leaves and root bark and compounds 1, 6-8, were isolated for the first time from Nectandra genus.

  9. Regeneration of Andrographis paniculata Nees: Analysis of genetic ...

    African Journals Online (AJOL)

    Andrographis paniculata Nees is a valuable medicinal plant which yields the therapeutic compound andrographolide. The objective of the present study was to develop reliable in vitro propagation techniques in this plant species. The efficiency of shoot regeneration in A. paniculata was tested on the Murashige and Skoog ...

  10. A decade of continuous NEE measurements at a Scottish peatland

    Science.gov (United States)

    Helfter, Carole; Campbell, Claire; Coyle, Mhairi; Anderson, Margaret; Drewer, Julia; Levy, Peter; Famulari, Daniela; Twigg, Marsailidh; Skiba, Ute; Billett, Michael; Dinsmore, Kerry; Nemitz, Eiko; Sutton, Mark

    2013-04-01

    Eddy-covariance measurements of carbon dioxide (CO2) fluxes have been running continuously at the Auchencorth Moss peatland site in Scotland (55o47'32N, 3o14'35W, 267 m a.s.l.) since the spring of 2002 which makes this study one of the longest ones to date on a peatland system. Auchencorth Moss is a low-lying, ombrotrophic peatland situated ca. 20 km south-west of Edinburgh. Peat depth ranges from 0.5 m and the site has a mean annual precipitation of 1155 mm. The open moorland site has an extensive uniform fetch of blanket bog to the south, west and north. The vegetation present within the flux measurement footprint comprises mixed grass species, heather and substantial areas of moss species (Sphagnum spp. and Polytrichum spp.). The eddy-covariance system consists of a Licor 7000 closed-path infrared gas analyser operating at 10 Hz for the simultaneous measurement of carbon dioxide and water vapour and of a Gill Windmaster Pro ultrasonic anemometer, operating at 20 Hz, and mounted atop a 3 m mast. The effective measurement height is 3.5 m with a vertical separation of 20 cm between the anemometer and the inlet of the sampling line. Air is sampled at 20 litres per minute through a 40 m long Dekabon line (internal diameter 4 mm). In addition to eddy-covariance measurements, the site is equipped with a weather station, soil temperature measurements, total solar radiation and photosynthetically active radiation (PAR) sensors, a tipping bucket for rainfall and, since April 2007, water table depth has been recorded at half-hourly interval. On an annual basis, the peatland at Auchencorth Moss has consistently been a net sink of CO2 in the study period 2002-2012 with a mean net ecosystem exchange (NEE) of - 69.1 ± 33.6 g C-CO2 m-2 yr-1. This value is at the high end of other recent studies as is the inter-annual range of NEE (-31.4 to -135.9 g C-CO2 m-2 yr-1). Inter-annual variations in NEE are significant and strongly correlated to the length of the growing seasons

  11. sciARTbooklet: Rachael Nee / Potato Powered Cosmos

    CERN Multimedia

    Hoch, Michael

    2017-01-01

    Rachael Nee rachaelnee@gmail.com graduated from MA Fine Art at Chelsea College of Arts, UK with Distinction in 2015, her art practice is concerned with energy, entropy and matter. www.rachaelnee.comart@CMS_sciARTbooklet: web page : http://artcms.web.cern.ch/artcms/ A tool to support students with their research on various scientific topics, encourage an understanding of the relevance of expression through the arts, a manual to recreate the artwork and enable students to define and develop their own artistic inquiry in the creation of new artworks. The art@CMS sciART booklet series directed by Dr. Michael Hoch, michael.hoch@cern.ch scientist and artist at CERN, in collaboration with the HST 2017 participants (S. Bellefontaine, S. Chaiwan, A. Djune Tchinda, R. O’Keeffe, G. Shumanova)

  12. Leaf anatomy of Odontonema strictum (Nees O. Kuntze (Acanthaceae

    Directory of Open Access Journals (Sweden)

    Maria Regina T. Boeger

    2006-12-01

    Full Text Available This study investigated the leaf anatomy of Odontonema strictum (Nees O. Kuntze (Acanthaceae, with emphasis on cystoliths, which are very abundant in this species. Leaves fully expanded from five mature individuals were collected in the teaching garden of the “Setor de Ciências Biológicas” (UFPR and fixed in FAA 70. The cystoliths were located in the epidermal cells of the adaxial face (litocysths and also among the collenchyma cells of the midrib and petiole. The cystoliths were cylindrical, long, with several small projections. They sometimes occurred in pairs and varied greatly in size, with an average length of 163.4±68.8 µm and a density of 23±9.97 cystoliths.mm-2 (n=10. The foliar lamina presented a uniseriate epidermis, dorsiventral mesophyll, and palisade parenchyma, which was continuous along the lamina. In the midrib, arc-shaped vascular veins were surrounded by fundamental parenchyma. Glandular trichomes occurred on both faces of the leaf, while non-glandular trichomes and diacytic stomata were present only on the abaxial face. The great number and size of the cystoliths observed could be related to defenses against herbivory and to mechanisms of removal of excess calcium absorbed from the soil.

  13. NACP VPRM NEE Parameters Optimized to North American Flux Tower Sites, 2000-2006

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides Vegetation Photosynthesis Respiration Model (VPRM) net ecosystem exchange (NEE) parameter values optimized to 65 flux tower sites across North...

  14. AirMOSS: L4 Modeled Net Ecosystem Exchange (NEE), Continental USA, 2012-2014

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides Level 4 estimates of Net Ecosystem Exchange (NEE) of CO2 across the conterminous USA at a spatial resolution of 50 km. Modeled estimates are...

  15. Nee omingud, päävad ja õhtad / Enda Naaber

    Index Scriptorium Estoniae

    Naaber, Enda, 1938-

    2006-01-01

    Järvesalu, Irma. Nänne kink oo nee õhtad : murdeluulet / toimetaja Kadri Tüür ; illustratsioonid: Viire Jagomägi ; kujundanud Riina Uisk. Tupenurme : I. Järvesalu, 2006. Sisaldab katkendeid luuletustest "Nänne kink", "Me jõudsime mere juure", "Kuoruke" ja "Meri"

  16. Crescimento de canela-lageana, Ocotea pulchella Nees et Mart. ex Nees, na Depressão Central do estado do Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    Luciano Scheeren Weber

    2003-01-01

    Full Text Available This work had as objectives the study of the growth in DBH, commercial volume (CV, current annual increment in percentage of the commercial volume (CAI and the determination of the commercial form factor (f for Ocotea pulchella Nees et Mart. ex Nees, in the Central Depression of the Rio Grande do Sul State. The growth data were tested with three mathematical equations, for the adjustment of diameter and commercial volume without bark. The quadratic equation resulted as a more efficient model, for the CV and DBH estimate, adjusted in function of the age of the trees. The Backman equation was selected for the CAI and for the f estimate. The values were determined in function of the DBH to facilitate practical application. The commercial form factor varied from 0,40 for a DBH of 5 cm to a maximum value of 0,85 for a DBH from 22 to 32 cm, decreasing up to 0,78 at 51 cm of DBH, between the ages of 10 and 100 years. The average annual increment in percentage of the commercial volume varied from 17,48% for 10 years to 1,33% for 100 years of age. The species presented a good growth potential, that associated with management practices can increase its productivity.

  17. Anti-inflammatory activity of the leaf extacts of Gendarussa vulgaris Nees.

    Science.gov (United States)

    Saleem, T K Mohamed; Azeem, A K; Dilip, C; Sankar, C; Prasanth, N V; Duraisami, R

    2011-04-01

    To evaluate the anti-inflammatory property of the leaf exacts of Gendarussa vulgaris (G. vulgaris) Nees. G. vulgaris Nees of the family Apocynaceae is a medium sized tree grown in semishade or no shade and is common in the Ernad and Nilambur taluks of Kerala.Various parts of this plant have been used in the treatment of ulcers, sores, inflammation, dyspepsia, healing of wounds, etc. The present study aimed at the evaluation of anti-inflammatory property of the aqueous and alcoholic extracts of the leaves by both in vitro and in vivo methods. In vitro method was estimated by human red blood cell membrane stabilisation (HRBC) method and in vivo method was estimated on the carrageenan induced paw oedima. Both the methods showed significant anti-inflammatory property of the different extracts tested. The alcoholic extract at a concentration of 300 mg/mL showed potent activity on comparing with the standard drug diclofenac sodium.

  18. Asteracantha longifolia (L. Nees, Acanthaceae: chemistry, traditional, medicinal uses and its pharmacological activities - a review

    Directory of Open Access Journals (Sweden)

    Nagendra Singh Chauhan

    2010-09-01

    Full Text Available Asteracantha longifolia (L. Nees, Acanthaceae, is a source of the ayurvedic drug, 'Kokilaaksha' and the Unani drug, Talimakhana. The seeds are acrid, bitter, aphrodisiac, tonic, sedative, used for diseases of the blood. The plant is known to possess antitumor, hypoglycemic, aphrodisiac, antibacterial, free radical scavenging and lipid peroxidation, hepatoprotective and haematopoietic activity. It contains lupeol, stigmasterol, butelin, fatty acids, and alkaloids. The present review article is focused on phytochemical, pharmacological and other important aspects of Talimakhana.

  19. "Antik? Oh, nee.": Antigone und die Folgen: Sophokles, Hegel, Freud, Butler

    OpenAIRE

    Frei Gerlach, Franziska

    2017-01-01

    Based on a comprehensive cultural-history approach, this essay argues that the selection of Oedipus as the basic model for psychoanalytical theory represents a negation of Antigone, the relevant sibling relation, and the horizontally structured family model. This negation will also be identified in Sigmund Freud's punch line "Antik? Oh, nee.” Taking Sophocles's play as a point of reference, this article reviews different interpretations of Antigone around 1800, 1900, and 2000. They are given ...

  20. AirMOSS: L4 Daily Modeled Net Ecosystem Exchange (NEE), AirMOSS sites, 2012-2014

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides Level 4 daily estimates of Net Ecosystem Exchange (NEE) of CO2 at a spatial resolution of 30 arc-seconds (~1 km) for seven of the sites...

  1. PRELIMINARY PHYTOCHEMICAL SCREENING AND ACUTE ORAL TOXICITY STUDY OF THE FLOWER OF PHLOGACANTHUS THYRSIFLORUS NEES IN ALBINO MICE

    OpenAIRE

    Chakravarty Sharmistha; Kalita Jogen Chandra

    2012-01-01

    Medicinal plants contains a variety of chemical substances with important therapeutic properties that can be utilised in the treatment of human diseases. Phlogacanthus thyrsiflorus Nees of family Acanthaceae is used in folklore remedies for treatment of Cough, Bronchitis, Fever, Asthama, Cancer and many other ailments. The present investigation was carried out to assess the qualitative phytochemical analysis of aqueous extract of the flower of Phlogacanthus thyrsiflorus Nees. The phytochemica...

  2. Using model-data fusion to analyze the interannual variability of NEE of an alpine grassland

    Science.gov (United States)

    Scholz, Katharina; Hammerle, Albin; Hiltbrunner, Erika; Wohlfahrt, Georg

    2017-04-01

    To understand the processes and magnitude of carbon dynamics of the biosphere, modeling approaches are an important tool to analyze carbon budgets from regional to global scale. Here, a simple process-based ecosystem carbon model was used to investigate differences in CO2 fluxes of a high mountain grassland near Furka Pass in the Swiss central Alps at an elevation of about 2400 m a.s.l. during two growing seasons differing in snow melt date. Data on net ecosystem CO2 exchange (NEE) as well as meteorological conditions was available from 20.06.2013 - 08.10.2014 covering two snow free periods. The NEE data indicates that the carbon uptake during the growing season in 2013 was considerably lower than in 2014. To investigate whether the lower carbon uptake in 2013 was mainly due to the short growing season, an effect of biotic response to spring environmental conditions, or the direct effect of the weather conditions during the growing season, a modeling approach was applied. For this purpose, an ecosystem mass balance C model with 13 unknown parameters was constructed based on the DALEC model to represent the major C fluxes among six carbon pools (foliage, roots, necromass, litter, soil organic carbon and a labile pool to support leaf onset in spring) of the grassland ecosystem. Daily gross primary production was estimated by use of a sun/shade big-leaf model of canopy photosynthesis. By calibrating the model with NEE data from individual years, two sets of parameters were retrieved which were then used to run the model under environmental conditions of the same as well as the other year. The parameter estimation was done using DREAM, an algorithm for statistical inference of parameters using Bayesian statistics. In order to account for non-normality, heteroscedasticity and correlation of model residuals, a common problem in ecological modeling, a generalized likelihood function was applied. The results indicate that the late growing season start in 2013 led to a

  3. La atención a los padres con hijos con necesidades educativas especiales (NEE)

    OpenAIRE

    Claudia María Pernas Pico

    2011-01-01

    Los padres que tienen hijos con necesidades educativas especiales (NEE) necesitan al igual que sus hijos de la intervención del maestro de Audición y Lenguaje con el objetivo primordial de mejorar la comunicación y el lenguaje de los niños. Se pretende en este artículo dar un abanico de posibilidades de cómo se puede intervenir con los padres desde las escuelas: con largas horas de reuniones, con formación, con talleres, con actividades y juegos, con libretas viajeras, con pequeñas pautas, et...

  4. Morfo-anatomia da flor de Ocotea puberula (Rich. Nees (Lauraceae Morphology and anatomy of the flower of Ocotea puberula (Rich. Nees (Lauraceae

    Directory of Open Access Journals (Sweden)

    Ismar Sebastião Moscheta

    1999-07-01

    Full Text Available A flor de Ocotea puberula (Rich. Nees foi estudada morfo-anatomicamente de plantas de floresta secundária de Maringá, Paraná, Brasil, uma região crítica com menos de 1% de cobertura vegetal. O estudo também consistiu de observações sobre antese e insetos visitadores de flores dessa espécie. A antese é diurna e a flor pode ser visitada por insetos pertencentes às ordens Hymenoptera, Lepidoptera, Diptera, Thysanoptera e Hemiptera. As tépalas têm epiderme simples e mesofilo parenquimático homogêneo. Os nectários são globosos, parenquimáticos, com predominância de tecido vascular floemático. As anteras são tetrasporangiadas e sua estrutura revela epiderme, endotécio, duas ou três camadas médias e tapete secretor. O gineceu possui estigma com papilas uni ou bicelulares, ovário de parede estruturalmente simples e óvulo anátropo bitegumentado. As flores femininas têm anteras estéreis e as masculinas pistilódio, o que caracteriza a espécie tipicamente como dióica.The morphology and anatomy of the flower of Ocotea puberula (Rich. Nees (Lauraceae are studied in the secondary forest of Maringá, state of Paraná, Brazil, a critical region with less than 1% of its area covered by forests. The study also consists of observations about anthesis and pollination of the species. The anthesis is diurnal and the flower may be visited by insects belonging to the Hymenoptera, Lepidoptera, Diptera, Thysanoptera and Hemiptera orders. The tepals have simple epidermis and homogeneous parenchymatous mesophyll. The nectaries are globose, parenchymatous and the terminal branches closest to the nectary consist principally of phloem. The anthers have four pollen sacs, endothecium, two or three middle layers and secretory tapetum. The gynoecium has stigma with uni or bicellular epidermic papillae, simple ovary wall and anatropous ovule with two integuments. The female flowers have sterile anthers and the male flowers have pistilode, which

  5. EXPERIMENTAL AND COMPUTATIONAL ACTIVITIES AT THE OREGON STATE UNIVERSITY NEES TSUNAMI RESEARCH FACILITY

    Directory of Open Access Journals (Sweden)

    S.C. Yim

    2009-01-01

    Full Text Available A diverse series of research projects have taken place or are underway at the NEES Tsunami Research Facility at Oregon State University. Projects range from the simulation of the processes and effects of tsunamis generated by sub-aerial and submarine landslides (NEESR, Georgia Tech., model comparisons of tsunami wave effects on bottom profiles and scouring (NEESR, Princeton University, model comparisons of wave induced motions on rigid and free bodies (Shared-Use, Cornell, numerical model simulations and testing of breaking waves and inundation over topography (NEESR, TAMU, structural testing and development of standards for tsunami engineering and design (NEESR, University of Hawaii, and wave loads on coastal bridge structures (non-NEES, to upgrading the two-dimensional wave generator of the Large Wave Flume. A NEESR payload project (Colorado State University was undertaken that seeks to improve the understanding of the stresses from wave loading and run-up on residential structures. Advanced computational tools for coupling fluid-structure interaction including turbulence, contact and impact are being developed to assist with the design of experiments and complement parametric studies. These projects will contribute towards understanding the physical processes that occur during earthquake generated tsunamis including structural stress, debris flow and scour, inundation and overland flow, and landslide generated tsunamis. Analytical and numerical model development and comparisons with the experimental results give engineers additional predictive tools to assist in the development of robust structures as well as identification of hazard zones and formulation of hazard plans.

  6. Anti-inflammatory activity of the leaf extacts of Gendarussa vulgaris Nees

    Science.gov (United States)

    Saleem, TK Mohamed; Azeem, AK; Dilip, C; Sankar, C; Prasanth, NV; Duraisami, R

    2011-01-01

    Objective To evaluate the anti-inflammatory property of the leaf exacts of Gendarussa vulgaris (G. vulgaris) Nees. Methods G. vulgaris Nees of the family Apocynaceae is a medium sized tree grown in semishade or no shade and is common in the Ernad and Nilambur taluks of Kerala.Various parts of this plant have been used in the treatment of ulcers, sores, inflammation, dyspepsia, healing of wounds, etc. The present study aimed at the evaluation of anti-inflammatory property of the aqueous and alcoholic extracts of the leaves by both in vitro and in vivo methods. In vitro method was estimated by human red blood cell membrane stabilisation (HRBC) method and in vivo method was estimated on the carrageenan induced paw oedima. Results Both the methods showed significant anti-inflammatory property of the different extracts tested. Conclusions The alcoholic extract at a concentration of 300 mg/mL showed potent activity on comparing with the standard drug diclofenac sodium. PMID:23569746

  7. Rebrotamento de capim caninha (Andropogon lateralis Nees sob o efeito do fogo Budding of "caninha" grass (Andropogon lateralis Nees under burning effect

    Directory of Open Access Journals (Sweden)

    José Pedro Pereira Trindade

    2001-12-01

    Full Text Available O presente trabalho foi conduzido com o objetivo de determinar o efeito de disponibilidade de matéria seca de uma pastagem natural, no momento da queima, na posterior taxa de crescimento foliar de Andropogon lateralis Nees. Foi realizado de 1995 a 1996, em área pertencente ao Departamento de Zootecnia da Universidade Federal de Santa Maria. O delineamento experimental utilizado foi o blocos completamente casualisados, com 40 plantas por tratamento. A queima foi realizada em agosto de 1995. Em maio de 1996, na área experimental, foram simulados níveis de disponibilidade de matéria seca através de roçadas com segadeira. Os tratamentos de pastagem foram testemunha sem queima (2.860kg de matéria seca (MS/ha e tratamentos de queima com disponibilidades de 2.580, 5.000, 5.690 e 6.480kg MS/ha. A avaliação do crescimento foliar foi feita em 600 afilhos marcados de A. lateralis e a metodologia utilizada para determinar o crescimento foliar foi o índice Haun. Houve efeito de queima na forma do aumento da taxa de alongamento de lâminas foliares (TA de A. lateralis quando a disponibilidade de matéria seca foi de 6.480kg MS/ha. Os demais tratamentos proporcionaram TA semelhantes aos de área não queimada. A. lateralis demonstrou ser uma espécie adaptada ao manejo com fogo, com rápido crescimento após a queima. A escala decimal de Haun demonstrou ser metodologia útil no estudo do rebrotamento de plantas.The present task was carried out with the objective of determining the effect of available dry matter of a natural grassland during burning in the post Andropogon lateralis Nees leaf growth rate. The work was executed during the years of 1995 and 1996 in an area belonging to the Department of Animal Science of the Universidade Federal de Santa Maria. The experimental design was randomized blocks with 40 plants per treatments. Burning was applied in August of 1995. In May of 1996 levels of dry matter were simulated in the experimental area

  8. A satellite view of riverine turbidity plumes on the NE-E Brazilian coastal zone

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    Eduardo Negri de Oliveira

    2012-09-01

    Full Text Available Turbidity plumes of São Francisco, Caravelas, Doce, and Paraiba do Sul river systems, located along the NE/E Brazilian coast, are analyzed for their dispersal patterns of Total Suspended Solids (TSS concentration using Landsat images and a logarithmic algorithm proposed by Tassan (1987 to convert satellite reflectance values to TSS. The TSS results obtained were compared to in situ collected TSS data. The analysis of the satellite image data set revealed that each river system exhibits a distinct turbidity plume dispersal pattern. The behavior, dimension and degree of turbidity of the São Francisco River plume have been greatly altered by the construction of a cascade of hydroelectric dam reservoirs in its hydrological basin. The plume has lost its typical unimodal seasonal pattern of material dispersion and its turbidity has decreased due to the regulation of river flow by the dams and TSS retainance by the reservoirs. In contrast, the Doce and Paraíba do Sul river plumes are still subject to seasonal pulsations and show more turbid conditions than the SF plume, as dams are less numerous, set in the middle river sections and the natural river flow has been maintained. The Caravelas Coastal System river plume is restricted to near shore shallow waters dominated by resuspension processes. During austral spring and summer when NE-E winds prevail, all plumes generally disperse southward. Short-term northward reversals may occur in winter with the passage of atmospheric cold fronts. The São Francisco and Doce river plumes tend to disperse obliquely to the coast and transport materials further offshore, while the Caravelas and Paraíba do Sul plumes tend to disperse mainly parallel to the coast, enhancing TSS retention nearshore.O presente estudo analisa as plumas de turbidez dos sistemas dos rios São Francisco, Caravelas, Doce, e Paraiba do Sul localizados na costa NE/E do Brasil utilizando imagens Landsat e o algoritmo logarítmico para Total

  9. Overview of the NEES-Soft Experimental Program for Seismic Risk Reduction of Soft-Story Woodframe Buildings

    Science.gov (United States)

    John W. van de Lindt; Pouria Bahmani; Steven E. Pryor; Gary Mochizuki; Mikhail Gershfeld; Weichiang Pang; Ershad Ziaei; Elaina N. Jennings; Michael D. Symans; Xiaoyun Shao; Jingjing Tian; Doug Rammer

    2014-01-01

    The existence of thousands of soft-story woodframe buildings in California has been recognized as a disaster preparedness problem resulting in mitigation efforts throughout the state. The considerable presence of these large multi-family buildings in San Francisco prompted the city to mandate their retrofitting over the next seven years. The NEES-Soft project, whose...

  10. The genus Spathius Nees (Hymenoptera, Braconidae, Doryctinae in Mexico: occurrence of a highly diverse Old World taxon in the Neotropics

    Directory of Open Access Journals (Sweden)

    Sergey Belokobylskij

    2014-07-01

    Full Text Available Two new species of the parasitoid wasp genus Spathius Nees (Braconidae: Doryctinae from Mexico, S.mexicanus sp. n. and S. chamelae sp. n., are described and illustrated. These represent the second and third described species of this highly diverse Old World genus in the Neotropics, and the first described species recorded for the Mexican territory.

  11. The genus Spathius Nees (Hymenoptera, Braconidae, Doryctinae) in Mexico: occurrence of a highly diverse Old World taxon in the Neotropics

    Science.gov (United States)

    Belokobylskij, Sergey A.; Zaldívar-Riverón, Alejandro

    2014-01-01

    Abstract Two new species of the parasitoid wasp genus Spathius Nees (Braconidae: Doryctinae) from Mexico, S. mexicanus sp. n. and S. chamelae sp. n., are described and illustrated. These represent the second and third described species of this highly diverse Old World genus in the Neotropics, and the first described species recorded for the Mexican territory. PMID:25147464

  12. Lignanos diarildimetilbutanos y otros constituyentes aislados de Nectandra turbacensis (kunth nees (lauraceae

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    Víctor Macías Villamizar

    2014-01-01

    Full Text Available Ocho compuestos conocidos fueron aislados del extracto etanólico de corteza de Nectandra turbacensis (Kunth Nees (Lauraceae. Estos fueron identificados como ácido meso-dihidroguayarético 1, ácido treo-dihidroguayarético 2, sauriol B 3, y treo-austrobailignano-6 4; vitexina (8-C-β-D-glucopiranosil-5,7,4’-trihidroxiflavona 5; estigmast-4-en-3-ona 6 y la mezcla sitosterol 7 / estigmasterol 8. Las estructuras de los compuestos fueron elucidadas por métodos espectroscópicos, que incluyeron técnicas de RMN en 1D y 2D, CG/EM y por comparación de los datos espectroscópicos, reportados en la literatura de compuestos relacionados. Este es el primer reporte de la presencia de este tipo de compuestos en la especie. Se describen también las implicaciones quimiotaxonómicas; relacionadas con la presencia frecuente de lignanos en especies del género Nectandra.

  13. ADAPTAÇÕES CURRICULARES PARA ALUNOS COM NECESSIDADES EDUCACIONAIS ESPECIAIS (NEE: FORMAÇÃO NO ENSINO SUPERIOR

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    Maria de Lurdes Cró

    2009-06-01

    Full Text Available A Escola Inclusiva pressupõe um atendimento a uma população cada vez mais diversa e heterogênea, onde todos devem obter uma resposta qualificada para as suas necessidades educativas, através das adaptações curriculares ao Currículo formal. Deste modo, as escolas devem incluir nos seus projetos educativos as adaptações curriculares relativas ao processo de ensino e aprendizagem, necessárias para responder adequadamente às crianças e jovens com Necessidades Educativas Especiais (NEE, com vista a optimizar a sua participação nas actividades. Atualmente tornou-se um desafio determinar com exactidão quais os alunos com NEE e, consequentemente, quais os alunos a serem intervencionados pela Educação Especial, nomeadamente alunos com NEE de caráter permanente. Neste contexto, surge a Classificação Internacional de Funcionabilidade, Incapacidade e Saúde (CIF, preconizada pela OMS (2001 e actualizada em 2003, que constitui uma ferramenta pedagógica no processo de elegibilidade, avaliação e intervenção de alunos com NEE. Observa-se uma mudança de paradigma, onde se pretende não só classificar os níveis de funcionalidade do indivíduo, como também os factores ambientais que podem funcionar como barreiras ou facilitadores dessa mesma funcionalidade. Nesta perspectiva a formação de professores, é assim considerada como um factor importante para o sucesso. Deste modo a formação contínua deve preconizar e permitir uma mudança de práticas dos professores e educadores, isto é, uma mudança de prática na educação, na intervenção educativa.

  14. Prevention of natural grassland invasion by Eragrostis plana Nees using ecological management practices

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    Telmo Focht

    2012-08-01

    Full Text Available The objective of this research was to evaluate the effects of different types of disturbance on the ability of the natural grassland to avoid the invasion of Eragrostis plana Nees (South African lovegrass. The experiment was carried out in Dom Pedrito, Rio Grande do Sul, Brazil, in an area free of South African lovegrass, from Feb. 2004 to Apr. 2007. The treatments were: 1 grassland management regimes: exclusion; low grazing intensity (rotational grazing, ±10 cm; and high grazing intensity (continuous grazing, ±5 cm; 2 initial levels of soil disturbance: high grassland, ±10 cm; low grassland, ±5 cm height; and low grassland with scarified soil; 3 fertilization regimes: without fertilization; phosphorus; and nitrogen. The experimental design was a split-split-plot type in complete blocks, with three replicates. Three winter cultivated species - Trefoil repens L., Lotus corniculatus L., Lolium multiflorum Lam. and South African lovegrass -were sown in 54 split-splitplots (split-plots: low grassland, and low grassland with scarified soil. The other 27 split-split-plots (split-plots: high grassland were sown only with South African lovegrass. The grassland height, plant number of South African lovegrass, grassland dry mass and photosynthetic active radiation intercepted (FARint at the soil level were recorded. The fertilization regimes did not influence the South African lovegrass plant number. The initial levels of soil disturbance and grassland management regimes influenced the invasion of South African lovegrass. The invasion was favored by the lower grassland height and lower forage mass, higher intensity of the soil disturbance, and higher FARint due to the continuous grazing. On the contrary, higher grassland height, higher forage mass, lower soil disturbance and lower FARint, associated with rotational grazing or exclusion, showed higher potential to control the invasion of South African lovegrass in the natural grassland.

  15. Germination of Ocotea pulchella (Nees Mez (Lauraceae seeds in laboratory and natural restinga environment conditions

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    LA. Pires

    Full Text Available The germination response of Ocotea pulchella (Nees Mez seeds to light, temperature, water level and pulp presence is introduced. The laboratory assays were carried out in germination chambers and thermal-gradient apparatus, whereas the field assays were performed in environments with distinct light, temperature and soil moisture conditions within a permanent parcel of Restinga forest of the Parque Estadual da Ilha do Cardoso, Cananéia, São Paulo. The seeds do not exhibit dormancy, they are non photoblastic, and a loss of viability in dry stored seeds can be related to a decrease in water content of the seed. The presence of the pulp and the flooded substratum influenced negatively the germination of O. pulchella seeds tested in the laboratory. Otherwise, light and temperature probably are not limiting factors of the germination of O. pulchella seeds in the natural environment of Restinga. The optimum temperature range for germination of Ocotea pulchella seeds was 20 to 32 ºC, the minimum or base temperature estimated was 11 ºC and the maximum ranged between 33 and 42 ºC. The isotherms exhibited a sigmoidal pattern well described by the Weibull model in the sub-optimal temperature range. The germinability of O. pulchella seeds in the understorey, both in wet and dry soil, was higher than in gaps. Germination was not affected by fluctuations in soil moisture content in the understorey environment, whereas in gaps, germination was higher in wet soils. Thus, the germination of this species involves the interaction of two or more factors and it cannot be explained by a single factor.

  16. Potential NEE Budget and Prediction of Future Emissions under Climate Change in an Arctic Wet Sedge Tundra, Barrow, Alaska .

    Science.gov (United States)

    Kalhori, A. A. M.; Oechel, W. C.; Burba, G. G.; Gioli, B.; Zona, D.; Murphy, P.; Goodrich, J. P.

    2015-12-01

    Arctic ecosystems are critically affected by climate change and also play an important role in the global carbon budget. Presented here is a 14-year study of growing season CO2 fluxes in an Alaskan wet sedge tundra ecosystem -which is about 2 km south of the Arctic Ocean and is adjacent to the NOAA Climate Monitoring & Diagnostic Laboratory (CMDL)- and the key environmental controls on these fluxes. We have measured net ecosystem exchange of CO2 (NEE) using the eddy covariance technique from 1998 to 2014 in order to quantify the long-term seasonal and inter-annual variability in the CO2 budget over this period. The WPL correction and the surface heating correction were applied to all CO2 flux data from the open-path instrument (Burba et al., 2008). Despite several gaps in measurement years, we found that growing season net CO2 uptake has significantly increased since the 2000s and that NEE is sensitive to dry conditions in tundra. Our data suggest this increase in CO2 uptake (larger than -6 μmol m-2 s-1) occurred during the initial thawing period and during the June-August growing season. However, there is a decreasing trend in total summer uptake beginning in 2011, continuing until the end of 2014. The mean diurnal pattern for the summer period over the course of 14 years (Figure below), indicates inter-annual variability associated with the key environmental controls on these CO2 fluxes. Monthly trends in Photosynthetically Active Radiation (PAR), net radiation, relative humidity as well as air temperature and soil temperature have consistently simultaneous effects on the variation in NEE. More significant effect of PAR than temperature on summer NEE had been observed for the first period of this study, however our ANOVA, multiple regression and t-test results showed a stronger effect of temperature than PAR in the recent years assuming that Arctic warming will be greater than average global warming. Also the diurnal pattern shows that the maximum daily carbon

  17. Asteracantha longifolia (L. Nees, Acanthaceae: chemistry, traditional, medicinal uses and its pharmacological activities - a review Asteracantha longifolia (L. Nees, Acanthaceae: química, usos tradicionais e medicinais e suas atividades farmacológicas - uma revisão

    Directory of Open Access Journals (Sweden)

    Nagendra Singh Chauhan

    2010-11-01

    Full Text Available Asteracantha longifolia (L. Nees, Acanthaceae, is a source of the ayurvedic drug, 'Kokilaaksha' and the Unani drug, Talimakhana. The seeds are acrid, bitter, aphrodisiac, tonic, sedative, used for diseases of the blood. The plant is known to possess antitumor, hypoglycemic, aphrodisiac, antibacterial, free radical scavenging and lipid peroxidation, hepatoprotective and haematopoietic activity. It contains lupeol, stigmasterol, butelin, fatty acids, and alkaloids. The present review article is focused on phytochemical, pharmacological and other important aspects of Talimakhana.Asteracantha longifolia (L. Nees, Acanthaceae, é a fonte do medicamento ayurvédico "Kokilaaksha", e da droga Unani, Talimakhana. As sementes têm de sabor acre e amargas, são afrodisíacas, tônicas, calmantes, e usadas para doenças do sangue. A planta é conhecida por possuir propriedades antitumorais, hipoglicêmica, afrodisíaca, anti-bacteriana, na eliminação de radicais livres e peroxidação lipídica, atividade hepatoprotetora e hematopoiéticas. Ele contém lupeol, estigmasterol, butelina, ácidos graxos e alcaloides. Este trabalho apresenta estudos químicos, farmacológicos e outros aspectos importantes da Talimakhana.

  18. Herb-drug interaction of Andrographis paniculata (Nees) extract and andrographolide on pharmacokinetic and pharmacodynamic of naproxen in rats.

    Science.gov (United States)

    Balap, Aishwarya; Lohidasan, Sathiyanarayanan; Sinnathambi, Arulmozhi; Mahadik, Kakasaheb

    2017-01-04

    Andrographis paniculata Nees (Acanthacae) have broad range of pharmacological effects such as hepatoprotective, antifertility, antimalarial, antidiabetic, suppression of various cancer cells and anti-inflammatory properties and is widely used medicinal plant in the traditional Unani and Ayurvedic medicinal systems. Andrographolide (AN) is one of the active constituent of the A. paniculata Nees extract (APE). They have been found in many traditional herbal formulations in India and proven to be effective as anti-inflammatory drug. To evaluate the pharmacokinetic and pharmacodynamic (anti arthritic) herb-drug interactions of A. paniculata Nees extract (APE) and pure andrographolide (AN) with naproxen (NP) after oral co-administration in wistar rats. After oral co-administration of APE (200mg/Kg) and AN (60mg/kg) with NP (7.5mg/kg) in rats, drug concentrations in plasma were determined using HPLC method. The main pharmacokinetic parameters of C max , t max , t 1/2 , MRT, Vd, CL, and AUC were calculated by non-compartment model. Change in paw volume, mechanical nociceptive threshold, mechanical hyperalgesia, histopathology and hematological parameters were evaluated to study antiarthritic activity. Co-administration of NP with APE and pure AN decreased systemic exposure level of NP in vivo. The C max , t max, AUC 0-t of NP was decreased. In pharmacodynamic study, NP (10mg/kg) alone and NP+AN (10+60mg/kg) groups exhibited significant synergistic anti-arthritic activity as compared to groups NP+APE, APE and AN alone. The results obtained from this study suggested that NP, APE and pure AN existed pharmacokinetic herb-drug interactions in rat which is correlated with anti-arthritic study. The knowledge regarding possible herb-drug interaction of NP might be helpful for physicians as well as patients using AP. So further studies should be done to understand the effect of other herbal ingredients of APE on NP as well as to predict the herb-drug interaction in humans

  19. What have we Learned after a Decade of Experiments and Monitoring at the NEES@UCSB Permanently Instrumented Field Sites?

    Science.gov (United States)

    Steidl, J. H.; Civilini, F.; Seale, S. H.; Hegarty, P.

    2013-12-01

    The Wildlife Liquefaction Array (WLA) and Garner Valley Downhole Array (GVDA) located in southern California are facilities that for the last decade have been supported under the National Science Foundations George E. Brown, Jr., Network for Earthquake Engineering Simulation (NEES) program. These densely instrumented geotechnical and structural engineering field sites continuously record both acceleration and pore pressure, with accelerometers located on the surface and at various depths below the surface, and pore pressure transducers installed at depth within the liquefiable layers. Permanently instrumented structures for examining soil-foundation-structure interaction and a permanent cross-hole array at the sites have transformed these sites into multi-disciplinary earthquake engineering research facilities. Over the last decade, local and regional seismic activity, including multiple extremely active earthquake swarms, have produced a valuable new data set providing a unique opportunity to observe site response and the evolution of pore pressure generation with time throughout the liquefiable layer at an unprecedented level of detail. In addition to the earthquakes provided by nature, active testing experiments using the mobile shakers from NEES@UTexas and NEES@UCLA have produced an equally valuable data set on both site characterization studies and soil-foundation-structure interaction. The new observations of pore pressure and acceleration with depth are providing in situ empirical evidence documenting the range of ground motion levels at which the onset of nonlinear behavior and excess pore pressure begins, augmenting previous case history data, and laboratory data from cyclic tri-axial and centrifuge testing. The largest static pore pressure increases observed in the 'NEES' decade of monitoring were generated by four events at the WLA site, ranging in magnitude from 4.6 to 5.4 and all at distances less than 10km from the site. The largest peak horizontal

  20. Inter-annual variability of year-round NEE over 18 years, and environmental controls on seasonal patterns at an arctic wet sedge tundra, CMDL Barrow, Alaska

    Science.gov (United States)

    Kalhori, A. A. M.; Oechel, W. C.; Goodrich, J. P.; Gioli, B.; Burba, G. G.; Shen, S. S. P.; Murphy, P.; Zona, D.

    2016-12-01

    To refine understanding of the total annual carbon balance in the Arctic, it is critical to extend long-term site-level CO2 flux data collection. These data are critical to addressing the environmental controls and processes responsible for temporal variability and seasonal patterns of net ecosystem exchange of CO2 (NEE). This dataset represents the longest running eddy covariance tower in the Arctic, which is located in an Alaskan wet sedge tundra ecosystem and is adjacent to the NOAA Climate Monitoring & Diagnostic Laboratory (CMDL). In addition to analyzing the year-to-year controls on NEE and its long-term trends, this work will complement a parallel study of the 40 year record of CO2 concentration measurements from the NOAA Barrow synoptic sampling station. For long-term, retrospective measurements, missing values are unavoidable, resulting from system failure, sensors icing-up during winter, losing network connections due to the harsh conditions, necessary instrument repairs, etc. Therefore, to analyze the annual sums, diurnal patterns, and seasonal vs. annual fluxes, the choice of gap-filling approach is critical and can dominate the magnitude of uncertainties, especially for periods with long gaps (> 1 month). We have applied different gap-filling methods such as artificial neural networks (ANN), and multiple linear regression (MLR) driven by micrometeorological parameters in an effort to minimize the associated uncertainties. Following gap-filling, a stepwise multiple regression against meteorological drivers including average summer PAR, average air and soil temperature, growing season length, duration of the zero curtain, growing degree days (GDD), date of snow melt, date of freeze up, and length of the summer was applied to determine the parameters that best explain the magnitude and sign of NEE in different seasons. These statistical analyses show that growing degree days were strongly correlated with summer NEE, which increased with higher GDD

  1. Eragrostis plana Nees as a novel eco-friendly adsorbent for removal of crystal violet from aqueous solutions.

    Science.gov (United States)

    Filho, Augusto Cezar D; Mazzocato, Ana C; Dotto, Guilherme L; Thue, Pascal S; Pavan, Flávio A

    2017-08-01

    Eragrostis plana Nees (EPN) was used as new and eco-friendly adsorbent for the removal of crystal violet dye (CV) from aqueous solution. Specific surface area (BET), scanning electron microscopy (SEM), infrared spectroscopy (ATR-FTIR), point of zero charge (pHPZC), and modified Boehm titration method were used to characterize the EPN material. The effects of initial pH of solution, adsorbent mass, contact time and initial dye concentration, and temperature were studied in batch adsorption mode. Kinetic data were evaluated by pseudo-first-order and pseudo-second-order models. The result exhibited that pseudo-second-order model well described the adsorption kinetics of CV onto EPN. Langmuir, Freundlich, and Sips isotherm models were used for analysis of the isothermal data. The equilibrium data of adsorption of CV onto EPN was better fitted with the Sips isotherm. Based on the Sips isotherm model, the maximum adsorption capacity was 76.20 ± 1.20 mg g-1 at 333 K. A high desorption of CV from EPN was obtained using 1.00 mol L-1 of CH3COOH as eluent. The thermodynamic data indicated that the adsorption was spontaneous, endothermic, and physical process. EPN can be used as alternative adsorbent to remove CV from aqueous solution.

  2. Aporphine alkaloids from the leaves of Phoebe grandis (Nees) Mer. (Lauraceae) and their cytotoxic and antibacterial activities.

    Science.gov (United States)

    Omar, Hanita; Hashim, Najihah Mohd; Zajmi, Asdren; Nordin, Noraziah; Abdelwahab, Siddiq Ibrahim; Azizan, Ainnul Hamidah Syahadah; Hadi, A Hamid A; Ali, Hapipah Mohd

    2013-07-29

    The oxoaporphine alkaloid lysicamine (1), and three proaporphine alkaloids, litsericinone (2), 8,9,11,12-tetrahydromecambrine (3) and hexahydromecambrine A (4) were isolated from the leaves of Phoebe grandis (Nees) Merr. (Lauraceae). Compounds 2 and 3 were first time isolated as new naturally occurring compounds from plants. The NMR data for the compounds 2-4 have never been reported so far. Compounds 1 and 2 showed significant cytotoxic activity against a MCF7 (human estrogen receptor (ER+) positive breast cancer) cell line with IC₅₀ values of 26 and 60 µg/mL, respectively. Furthermore, in vitro cytotoxic activity against HepG2 (human liver cancer) cell line was evaluated for compounds 1-4 with IC₅₀ values of 27, 14, 81 and 20 µg/mL, respectively. Lysicamine (1) displayed strong antibacterial activity against Bacillus subtilis (B145), Staphylococcus aureus (S1434) and Staphylococus epidermidis (a clinically isolated strain) with inhibition zones of 15.50 ± 0.57, 13.33 ± 0.57 and 12.00 ± 0.00 mm, respectively. However, none of the tested pathogenic bacteria were susceptible towards compounds 2 and 3.

  3. Aporphine Alkaloids from the Leaves of Phoebe grandis (Nees Mer. (Lauraceae and Their Cytotoxic and Antibacterial Activities

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    A. Hamid A. Hadi

    2013-07-01

    Full Text Available The oxoaporphine alkaloid lysicamine (1, and three proaporphine alkaloids, litsericinone (2, 8,9,11,12-tetrahydromecambrine (3 and hexahydromecambrine A (4 were isolated from the leaves of Phoebe grandis (Nees Merr. (Lauraceae. Compounds 2 and 3 were first time isolated as new naturally occurring compounds from plants. The NMR data for the compounds 2–4 have never been reported so far. Compounds 1 and 2 showed significant cytotoxic activity against a MCF7 (human estrogen receptor (ER+ positive breast cancer cell line with IC50 values of 26 and 60 µg/mL, respectively. Furthermore, in vitro cytotoxic activity against HepG2 (human liver cancer cell line was evaluated for compounds 1–4 with IC50 values of 27, 14, 81 and 20 µg/mL, respectively. Lysicamine (1 displayed strong antibacterial activity against Bacillus subtilis (B145, Staphylococcus aureus (S1434 and Staphylococus epidermidis (a clinically isolated strain with inhibition zones of 15.50 ± 0.57, 13.33 ± 0.57 and 12.00 ± 0.00 mm, respectively. However, none of the tested pathogenic bacteria were susceptible towards compounds 2 and 3.

  4. In vitro antioxidant activity of dewberry (Rubus caesius L. var. aquáticus Weihe. & Nees. leaf extracts

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    Veličković Ivona

    2015-01-01

    Full Text Available In this study, the antioxidant properties and total phenolic and flavonoid contents of Rubus caesius L. var. aquáticus Weihe & Nees leaf extracts were examined. The radical scavenging capacity of four leaf extracts (methanol, ethanol, acetone and aqueous was estimated against 2,2-diphenyl-1-picrylhydrazil (DPPH and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS assays. Total antioxidant capacity was tested by ferric reducing ability of plasma (FRAP and total reducing capacity (TRC procedures. Total contents of phenols and flavonoids were also determined. Total phenol content in the extracts was determined using Folin-Ciocalteu reagent and amounts ranged between 263.74 for ethanol to 366.27 mg gallic acid (GA/g for acetone extracts. The amounts of flavonoids varied from 10.73 mg quercetin equivalent (QE/g for aqueous to 75.83 mg QE/g for acetone extract. The highest antioxidant activity against DPPH and ABTS●+ radicals was that of the acetone extract. Values for FRAP varied between 3.00 μmol Fe+2/mg for the ethanol extract and 5.31 μmol Fe+2/mg for the methanol extract. The results obtained for total reducing capacity indicate that the acetone extract has the highest antioxidant potential. [Projekat Ministarstva nauke Republike Srbije, br. 173029

  5. Light, Soil Temperature, and VPD as controls of flux-tower NEE partitioning into gross photosynthesis and respiration in grassland and agricultural ecosystems

    Science.gov (United States)

    Gilmanov, T. G.

    2010-12-01

    Partitioning of the flux-tower net CO2 exchange measurements (NEE) into gross photosynthesis (Pg) and ecosystem respiration (Re) components is an essential step in post-processing flux tower data for analysis and modeling. We have developed a method of NEE = Pg - Re partitioning using photosynthetically active radiation (Q), soil temperature at 5 cm depth (Ts), and vapor pressure deficit at 2 m height (VPD) as factors in a nonrectangular hyperbolic model of net CO2 exchange in terrestrial ecosystems (Gilmanov et al. 2003, Bas. Appl. Ecol. 4: 167-183) modified to include the effect of vapor pressure deficit. In contrast to other VPD-based methods of NEE partitioning suggested in the literature, our method (i) describes combined effect of VPD on photosynthetic capacity (Amax) and apparent quantum yield (ALPHA) due to the special functional properties of the nonrectangular hyperbolic equation; (ii) delivers less biased estimates of light-response parameters due to explicit description of the convexity of the light-response compared to rectangular hyperbolic model, and (iii) generates more numerically robust and statistically significant estimates than methods using highly correlated predictors such as incoming radiation, air temperature and VPD. We demonstrate application of the method to flux-tower NEE data sets from grassland and agro-ecosystems of North America as a tool to estimate numerical values and uncertainty characteristics of productivity, respiration, and ecophysiological parameters (apparent quantum yield ALPHA, photosynthetic capacity Amax, gross ecological light-use efficiency LUE, carbon use efficiency CUE, and others). On a representative statistical material our results confirm earlier findings that gross photosynthesis estimates derived through partitioning of flux-tower NEE are significantly closer related to remote sensing indices (e.g., eMODIS NDVI) than variables directly provided by tower measurements such as day-time net CO2 flux totals. We

  6. EFEK EKSTRAK SAMBILOTO (ANDROGRAPHIS PANICULATA NEES PADA EKSPRESI TELOMERASE DARI KANKER PAYUDARA TIKUS YANG DIINDUKSI DENGAN DMBA

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    Yurika Sastyarina

    2010-12-01

    penelitian efek ekstrak sambiloto (Andrographis paniculata Nees pada ekspresi telomerase terhadap kanker payudara tikus betina (Sprague dawley yang diinduksi dengan 7,12 dimethylbenz(aanthracene (DMBA menggunakan metode imunohistokimia. Diketahui model kanker payudara dengan induksi DMBA untuk menginvestigasi perubahan dari sel epitel yang terjadi selama prorses karsinogenesis kanker payudara. Pemberian ekstrak sambiloto pada tikus yang mengalami kanker payudara menyebabkan penurunan volume tumor dan ditinjau dari aspek hispatologi dan imunohistokimia adanya ekstrak sambiloto menyebabkan penghambatan proliferasi sel, penurunan ekspresi telomerase dan meningkatkan apoptosis.   Kata Kunci : Andrographis paniculata,DMBA, kanker payudara, proliferasi sel

  7. Divergent NEE balances from manual-chamber CO2 fluxes linked to different measurement and gap-filling strategies: A source for uncertainty of estimated terrestrial C sources and sinks?

    DEFF Research Database (Denmark)

    Huth, Vytas; Vaidya, Shrijana; Hoffmann, Mathias

    2017-01-01

    -study comparisons and meta analyses. The aim of this study was to compare common approaches for quantifying CO2 exchange at three methodological levels. (1) The first level included two different CO2 flux measurement methods: one via measurements during mid-day applying net coverages (mid-day approach) and one via......Manual closed-chamber measurements are commonly used to quantify annual net CO2 ecosystem exchange (NEE) in a wide range of terrestrial ecosystems. However, differences in both the acquisition and gap filling of manual closed-chamber data are large in the existing literature, complicating inter...... of the agricultural field diverged strongly (–200 to 425 g CO2-C m−2). NEE balances were most similar to previous studies when derived from sunrise measurements and indirect GPP modeling. Overall, the large variation in NEE balances resulting from different data-acquisition or gap-filling strategies indicates...

  8. Protective Effect of Adhatoda vascia Nees against Radiation-Induced Damage at Cellular, Biochemical and Chromosomal Levels in Swiss Albino Mice

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    Meenal Kumar

    2007-01-01

    Full Text Available Extract of Adhatoda vasica (L Nees leaves has been used for treatment of various diseases and disorders in Ayurved and Unani medicine. Modulatory effect of ethanolic extract of A. vasica (L Nees against radiation-induced changes in terms of histological alterations in testis, reduced glutathione (GSH, lipid peroxidation (LPO, acid and alkaline phosphatases levels, and chromosomal alterations in Swiss albino mice was studied at various post-irradiation intervals between 1 and 30 days. Mice exposed to 8 Gy radiation showed radiation-induced sickness including marked changes in histology of testis and chromosomal aberrations in bone marrow cells with 100% mortality within 22 days. When ethanolic leaf extract of A. vasica was given orally at a dose of 800 mg kg−1 body weight per mouse for 15 consecutive days and then exposed to radiation, death of Adhatoda-pretreated irradiated mice was reduced to 70% at 30 days. The radiation dose reduction factor was 1.43. There was significantly lesser degree of damage to testis tissue architecture and various cell populations including spermatogonia, spermatids and Leydig cells. Correspondingly, a significant decrease in the LPO and an increase in the GSH levels were observed in testis and liver of Adhatoda-pretreated irradiated mice. Similarly, a significant decrease in level of acid phosphatase and increase in level of alkaline phosphatase were observed. Adhatoda pretreatment significantly prevented radiation-induced chromosomal damage in bone marrow cells. The study suggests that Adhatoda plant extract has significant radioprotective effects on testis that warrants further mechanistic studies aimed at identifying the role of major ingredients in the extract.

  9. Control of anthracnose caused by Colletotrichum species in guava, mango and papaya using synergistic combinations of chitosan and Cymbopogon citratus (D.C. ex Nees) Stapf. essential oil.

    Science.gov (United States)

    Lima Oliveira, Priscila Dinah; de Oliveira, Kataryne Árabe Rimá; Vieira, Willie Anderson Dos Santos; Câmara, Marcos Paz Saraiva; de Souza, Evandro Leite

    2018-02-02

    This study assessed the efficacy of chitosan (Chi) and Cymbopogon citratus (D.C. ex Nees) Stapf. essential oil (CCEO) combinations to control the mycelial growth of five pathogenic Colletotrichum species (C. asianum, C. siamense, C. fructicola, C. tropicale and C. karstii) in vitro, as well as the anthracnose development in guava (Psidium guajava L.) cv. Paluma, mango (Mangifera indica L.) cv. Tommy Atkins and papaya (Carica papaya L.) cv. Papaya artificially inoculated with these species. Combinations of Chi (2.5, 5 or 7.5mg/mL) and CCEO (0.15, 0.3, 0.6 or 1.25μL/mL) inhibited the mycelial growth of all tested fungal species in vitro. Examined Chi-CCEO combinations showed additive or synergistic interactions to inhibit the target Colletotrichum species based on the Abbott index. Coatings formed by synergistic Chi (5mg/mL) and CCEO (0.15, 0.3 or 0.6μL/mL) combinations decreased anthracnose lesion development in guava, mango and papaya inoculated with any of the tested Colleotrichum species during storage. Overall, anthracnose lesion development inhibition in fruit coated with synergistic Chi-CCEO combinations was higher than that observed in fruit treated with synthetic fungicides. These results show that the application of coatings formed by Chi-CCEO synergistic combinations could be effective to control postharvest anthracnose development in fruit. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Hybrids and backcross progenies between wheat (Triticum aestivum L.) and apomictic Australian wheatgrass [Elymus rectisetus (Nees in Lehm.) A. Löve & Connor]: karyotypic and genomic analyses.

    Science.gov (United States)

    Liu, Z W; Wang, R R; Carman, J G

    1994-11-01

    Wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) florets were emasculated and pollinated using two apomictic wheatgrass [Elymus rectisetus (Nees in Lehm.) A. Love & Connor, 2n = 6x = 42, SSYYWW] accessions, one of which produces 2n pollen. A 2n = 42 (BII) hybrid and four 2n = 63 (B III) hybrids were obtained. The spike morphology of the B II hybrid was intermediate to that of its parents. The pollen mother cells (PMCs) of this hybrid contained on average 38.361 and 1.62 II, which was consistent with its disparate genome composition (ABDSYW). Its pollen failed to stain and no BC1 progeny was obtained. The B III hybrids (reduced egg fertilized with unreduced sperm) were grasslike and had a full complement of E. rectisetus chromosomes, the synapsis of which was slightly impaired by wheat haplome and/or cytoplasm. Their PMCs contained on average 16.30 II, 25.72 I, and 1.54 multivalents (III plus IV). Pollen stainability in these hybrids was low (<1%), and when they were used as females, one 54- and 60-chromosome BC1 were obtained. A mean of 13.25 II was observed in PMCs of the 54-chromosome BC1 and pollen stainability was 10%. Pollen stainability in the 60-chromosome BC1 was only 5%. The use of 2n-pollen-producing E. rectisetus accession accelerated hybrid and BC1 formation and may accelerate the ultimate transfer of apomixis to wheat.

  11. Ocorrência de Salmonella e coliformes de origem fecal na canela em pó (Cinnamomum cassia Blume a Cinnamomum zeylanicum Nees comercializada em Florianópolis, Santa Catarina, Brasil Salmonella and fecal coliforms in cinnamon (Cinnamomum cassia Blume and Cinnamomum zeylanicum Nees sold in the city of Florianópolis, Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Jane Maria de S. Philippi

    1995-12-01

    Full Text Available Cem amostras de canela em pó de dez marcas diferentes comercializadas na cidade de Florianópolis, SC, foram submetidas à análise microbiológica, pesquisando-se Salmonella e coliformes de origem fecal. Em nenhuma amostra foi detectada Salmonella. Coliformes de origem fecal foram encontrados entre os valores The microbiological quality of a hundred samples of ten differents commercial brands of a ground cinnamon (Cinnamomum cassia Blume and Cinnamomum zeylanicum Nees from supermarkets in the city of Florianópolis, Brazil, was assessed. Salmonella and fecal coliforms were determined. Results were negative for Salmonella Fecal coliforms values ranged from 100 MPN per g. Fecal coliforms were detected in 37% of the cinnamon samples.

  12. Hybrid analysis (barcode-high resolution melting) for authentication of Thai herbal products, Andrographis paniculata (Burm.f.) Wall.ex Nees.

    Science.gov (United States)

    Osathanunkul, Maslin; Suwannapoom, Chatmongkon; Khamyong, Nuttaluck; Pintakum, Danupol; Lamphun, Santisuk Na; Triwitayakorn, Kanokporn; Osathanunkul, Kitisak; Madesis, Panagiotis

    2016-01-01

    Andrographis paniculata Nees is a medicinal plant with multiple pharmacological properties. It has been used over many centuries as a household remedy. A. paniculata products sold on the markets are in processed forms so it is difficult to authenticate. Therefore buying the herbal products poses a high-risk of acquiring counterfeited, substituted and/or adulterated products. Due to these issues, a reliable method to authenticate products is needed. High resolution melting analysis coupled with DNA barcoding (Bar-HRM) was applied to detect adulteration in commercial herbal products. The rbcL barcode was selected to use in primers design for HRM analysis to produce standard melting profile of A. paniculata species. DNA of the tested commercial products was isolated and their melting profiles were then generated and compared with the standard A. paniculata. The melting profiles of the rbcL amplicons of the three closely related herbal species (A. paniculata, Acanthus ebracteatus and Rhinacanthus nasutus) are clearly separated so that they can be distinguished by the developed method. The method was then used to authenticate commercial herbal products. HRM curves of all 10 samples tested are similar to A. paniculata which indicated that all tested products were contained the correct species as labeled. The method described in this study has been proved to be useful in aiding identification and/or authenticating A. paniculata. This Bar-HRM analysis has allowed us easily to determine the A. paniculata species in herbal products on the markets even they are in processed forms. We propose the use of DNA barcoding combined with High Resolution Melting analysis for authenticating of Andrographis paniculata products.The developed method can be used regardless of the type of the DNA template (fresh or dried tissue, leaf, and stem).rbcL region was chosen for the analysis and work well with our samplesWe can easily determine the A. paniculata species in herbal products tested

  13. The anti-inflammatory effect of Andrographis paniculata (Burm. f.) Nees on pelvic inflammatory disease in rats through down-regulation of the NF-κB pathway.

    Science.gov (United States)

    Zou, Wei; Xiao, Zuoqi; Wen, Xiaoke; Luo, Jieying; Chen, Shuqiong; Cheng, Zeneng; Xiang, Daxiong; Hu, Jian; He, Jingyu

    2016-11-25

    Andrographis paniculata (Burm. f.) Nees (APN), a principal constituent of a famous traditional Chinese medicine Fukeqianjin tablet which is used for the treatment of pelvic inflammatory disease (PID), has been reported to have anti-inflammatory effect in vitro. However, whether it has pharmacological effect on PID in vivo is unclear. Therefore, the aim of this study is to test the anti-inflammatory effect of APN and illuminate a potential mechanism. Thirty-six female specific pathogen-free SD rats were randomly divided into control group, PID group, APN1 group, APN2 group, APN3 group and prednisone group. Pathogen-induced PID rats were constructed. The APN1, APN2 and APN3 group rats were orally administrated with APN extract at different levels. The prednisone group rats were administrated with prednisone. Eight days after the first infection, the histological examination of upper genital tract was carried out, and enzyme-linked immunosorbent assay (ELISA) was carried out using homogenate of the uterus and fallopian tube. Furthermore, immunohistochemical evaluations of NF-κB p65 and IκB-α in uterus was conducted. APN obviously suppressed the infiltrations of neutrophils and lymphocytes, and it could significantly reduce the excessive production of cytokines and chemokines including IL-1β, IL-6, CXCL-1, MCP-1 and RANTES in a dose-dependent manner. Furthermore, APN could block the pathogen-induced activation of NF-κB pathway. APN showed potent anti-inflammatory effect on pathogen-induced PID in rats, with a potential mechanism of inhibiting the NF-κB signal pathway.

  14. Assessing NEE and Carbon Dynamics Among European Forestecosystems: Development and Validation of a New Phenology and Soil Carbon Routines within the Process Oriented 3D-Cmcc-Forest-Ecosystem Model

    Science.gov (United States)

    Marconi, S.; Collalti, A.; Santini, M.; Valentini, R.

    2014-12-01

    The two main processes involved in forest ecosystems carbon balance are photosynthesis and respiration. Ecosystem respiration is determined by heterotrophic and autotrophic respiration, the former driven by microbial decomposition of soil organic matter (SOM), the latter by growth and maintenance of plant tissues. Thus it is extremely important to reliably quantify ecosystem respiration in order to estimate the global carbon budget of a forest ecosystem, namely the Net Ecosystem Exchange (NEE). For the very same reason we have improved the 6.1 version of the 3D-CMCC-Forest Ecosystem Model (3D-CMCC-FEM) with both a multilayer soil Carbon dynamics routine and several modifications in phenology and littering. Bud burst phenology has been improved with a new "Nonstructural Carbon injection function" representing the quantity of Carbon destined to new leaves and fineroots growth; fall phenology has been improved with a novel physical driven logistic function to simulate leaf falling. Soil carbon dynamics throughout the Residues, Microbial and Humads pools follow a zero order kinetics equation, representing microbial decomposition activity. The sum of CO2 oxidized at each decomposition step form Heterotrophic respiration.The present work focuses on the presentation of the 6.1 version of the 3D-CMCC-FEM and its validation against six FLUXNET sites representing a transect throughout the main European forest Ecosystems. The validation on about 10 years of simulation involved NEE, GPP and Reco: - Seasonal trends; - Daily, monthly and annual fluxes; - Interannual anomalies (annual and MJJ).

  15. Adaptações curriculares para alunos com necessidades educacionais especiais (nee: formação no ensino superior / Curriculum adaptations for students with special education needs (sen: training in higher education

    Directory of Open Access Journals (Sweden)

    Maria de Lurdes Cró

    2009-01-01

    Full Text Available A Escola Inclusiva pressupõe um atendimento a uma população cada vez mais diversa e heterogênea, onde todos devem obter uma resposta qualificada para as suas necessidades educativas, através das adaptações curriculares ao Currículo formal. Deste modo, as escolas devem incluir nos seus projetos educativos as adaptações curriculares relativas ao processo de ensino e aprendizagem, necessárias para responder adequadamente às crianças e jovens com Necessidades Educativas Especiais (NEE, com vista a optimizar a sua participação nas actividades. Atualmente tornou-se um desafio determinar com exactidão quais os alunos com NEE e, consequentemente, quais os alunos a serem intervencionados pela Educação Especial, nomeadamente alunos com NEE de caráter permanente. Neste contexto, surge a Classificação Internacional de Funcionabilidade, Incapacidade e Saúde (CIF, preconizada pela OMS (2001 e actualizada em 2003, que constitui uma ferramenta pedagógica no processo de elegibilidade, avaliação e intervenção de alunos com NEE. Observa-se uma mudança de paradigma, onde se pretende não só classificar os níveis de funcionalidade do indivíduo, como também os factores ambientais que podem funcionar como barreiras ou facilitadores dessa mesma funcionalidade. Nesta perspectiva a formação de professores,é assim considerada como um factor importante para o sucesso. Deste modo a formação contínua deve preconizar e permitir uma mudança de práticas dos professores e educadores, isto é, uma mudança de prática na educação, na intervenção educativa.Abstract The inclusive school requires a service provided to a population increasingly diverse and heterogeneous, by which everyone must get a qualified response to their educational needs through curriculum adaptations to the formal curriculum. Thus, schools should include the required curricular adaptations in their educational projects regarding the teaching and learning process, to

  16. ED-XRF spectrometric analysis of comparative elemental composition of in vivo and in vitro roots of Andrographis paniculata (Burm.f.) Wall. ex Nees-a multi-medicinal herb

    Energy Technology Data Exchange (ETDEWEB)

    Behera, P.R., E-mail: priyaranjan2004@gmail.co [Plant Cell and Tissue culture Facility, Post-Graduate Department of Botany, Utkal University, Vani Vihar, Bhubaneswar 751004, Orissa (India); Plant Biotechnology Lab, Institute of Minerals and Materials Technology (CSIR), Bhubaneswar 751013, Orissa (India); Nayak, P., E-mail: pranati_nayak_23@yahoo.co.i [Plant Cell and Tissue culture Facility, Post-Graduate Department of Botany, Utkal University, Vani Vihar, Bhubaneswar 751004, Orissa (India); Plant Biotechnology Lab, Institute of Minerals and Materials Technology (CSIR), Bhubaneswar 751013, Orissa (India); Barik, D.P., E-mail: barikdp@yahoo.co [Plant Cell and Tissue culture Facility, Post-Graduate Department of Botany, Utkal University, Vani Vihar, Bhubaneswar 751004, Orissa (India); Rautray, T.R., E-mail: trrautray@gmail.co [Ion Beam Laboratory, Institute of Physics, Bhubaneswar 751013, Orissa (India); Thirunavoukkarasu, M., E-mail: mtarasu@yahoo.co [Plant Biotechnology Lab, Institute of Minerals and Materials Technology (CSIR), Bhubaneswar 751013, Orissa (India); Chand, P.K., E-mail: pkchanduubot@yahoo.co.i [Plant Cell and Tissue culture Facility, Post-Graduate Department of Botany, Utkal University, Vani Vihar, Bhubaneswar 751004, Orissa (India)

    2010-12-15

    The multi-elemental composition of in vitro-proliferated root tissues of Andrographis paniculata (Burm.f.) Wall. ex Nees was compared with that of the naturally grown in vivo plants. Trace elements namely Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Rb, Sr and Pb in addition to two macro-elements K and Ca were identified and quantified in root tissues of both sources using the energy dispersive X-ray fluorescence (ED-XRF) technique. ED-XRF analysis was performed using Mo K X-rays generated from a secondary molybdenum target. The elemental content of in vitro roots was found to be at par with that of naturally grown plants of the same species. This opens up a possibility of exploiting in vitro root cultures as a viable, alternative and renewable source of phytochemicals of relevance, besides providing a means for conservation of the valuable natural resources.

  17. Micropropagation of Ocotea porosa (Nees & Martius) Barroso

    African Journals Online (AJOL)

    user

    2011-02-28

    Feb 28, 2011 ... The objective of this work was the establishment of a micropropagation protocol for Ocotea porosa by multiplication of shoots from axillary buds. Different concentration of BAP (0; 2.5; 5 or 10 µM) or. BAP+KIN (0; 1.25; 2.5 or 5 µM) were investigated to optimize the multiplication. Shoot growth was stimulated ...

  18. Quality Control Tests on Andrographis paniculata Nees (Family ...

    African Journals Online (AJOL)

    Purpose: To characterize the aerial parts of Andrographis paniculata, a bitter Indian herb grown in Nigeria, for the purpose of quality control. Methods: The determination of bitterness value and of various physicochemical characteristics; tests for key phytochemicals; and thin layer chromatography (TLC) of the air-dried herb, ...

  19. Climatic and edaphic conditions at Eragrostis lehmanniana Nees ...

    African Journals Online (AJOL)

    Climatic and edaphic conditions in central Botswana and north-eastern Namibia generally range between those in south-eastern Arizona and the Cape Province, RSA and we expect that seeded Lehmann lovegrass stands in these areas would enhance semi-desert grassland productivity. Keywords: arizona; botany ...

  20. Replacing Stipa trichotoma Nees (nasella) in the Eastern Cape | le ...

    African Journals Online (AJOL)

    The most effective grasses were Dactylis glomerata (cocksfoot), Phalaris tuberosa, Lolium multiflorum (Italian ryegrass), Lolium hybridum (Ariki ryegrass), Agrostis tenuis and Festuca arundinacea (Tall fescue). The most effective legumes were Vicia villosa (hairy vetch) and Trifolium pratense (red clover) Overseeding and ...

  1. Entrenament en atenció : Treball amb alumnat amb NEE

    OpenAIRE

    Páez Ballesteros, Irene

    2013-01-01

    The purpose of this project was to analyze the attention span of students with mental retardation with Autism Spectrum Disorder (Asperger Syndrome) and with mild intellectual disabilities and behavioral disorders of an USEE class in a secondary school. El motiu principal d'aquest projecte ha estat analitzar la capacitat d'atenció d'alumnes amb retard mental, amb Trastorn de l'Espectre Autista (síndrome d'Asperger) i amb discapacitats intel·lectuals lleus i Trastorns de Conducta d'una US...

  2. Growth and regrowth of tough lovegrass (Eragrostis plana Nees

    Directory of Open Access Journals (Sweden)

    Simone Meredith Scheffer-Basso

    2012-02-01

    Full Text Available This study evaluated the morphological development of two populations of tough lovegrass during 120 days of continuous growth (Experiment I, and the regrowth of one population under the combination of cutting height (5 cm and 10 cm and phenological stage at the first cutting (vegetative and beginning of flowering; Experiment II. In Experiment I, plants were harvested at 30, 60, 90 and 120 days of growth; in Experiment II, three cuttings were carried out at every 30 days, and the plants were harvested four weeks after the previous one. In Experiment I, the populations did not differ for morphological development, showing a linear increase in height and tiller number, and a quadratic trend for root and shoot dry matter (DM. At 120 days of growth, plants presented 10 basal tillers and 80 leaves, strongly compressed at the base and no sign of senescence. In Experiment II, there was no significant cutting height × phenological stage interaction, but cuttings at 5 cm reduced plant size and yield. Cuttings started at the vegetative stage decreased the root (3.06 g DM/plant and stubble dry matter (1.17 g DM/plant, compared with 6.84 g and 3.99 g DM/plant, respectively, with cuttings started at the flowering stage. Tough lovegrass shows basal architecture, basal bud renovation, leaves densely compressed in the tiller base, high belowground allocation, and elongation of internodes only in reproductive stage. Mechanical control is an alternative method to minimize its growth, especially if it is carried out early in the growing season and at low cutting height.

  3. Spectrophotometric determination of total lactones in Andrographis paniculata Nees

    Directory of Open Access Journals (Sweden)

    Napaporn Jantakun

    2005-11-01

    Full Text Available A spectrophotometric method for determination of total lactones in Andrographis paniculata was established by using dinitrobenzoic acid and potassium hydroxide solutions as colour forming agents. The absorbance of the solution was determined at 536 nm. The linearity range was 12-72 × 10-6 g.ml-1. The detection limit was 1.2 μg, the quantitation limit was 4.23 μg. The intraday variation had an average of slope 6082.97 g.ml-1, % RSD 0.10; an average intercept 0.2786, %RSD 3.66 (n=3. The interday variation had an average of 6146 g.ml-1 with the %RSD of 6.30 and an average intercept 0.2628, %RSD 4.95 (n=4. The coefficients of determination were 0.998-0.999. The total lactones content, calculated as andrographolide, determined by this method was 8.61±0.52% (n=4 and by the official method, Thai Herbal Pharmacopoeia, was 8.12±0.34% (n=2. The results of the two methods do not differ significantly at P=0.05 (P(|t|>0.903 = 0.53

  4. ANÁLISE DENDROECOLÓGICA DE Ocotea pulchella Nees et Mart. ex Nees (CANELA LAGEANA NA SERRA GERAL DE SANTA MARIA, RS, BRASIL

    Directory of Open Access Journals (Sweden)

    Peter Spathelf

    2000-06-01

    Full Text Available Foram estudadas as relações entre variáveis climáticas e o incremento em diâmetro do tronco de cinco árvores de Ocotea pulchella localizadas às margens de uma barragem no município de Itaára, RS. Os dados de crescimento, em diâmetro, foram obtidos mediante análise de tronco, utilizando-se seções transversais retiradas na altura de 1,3 m (DAP, sendo os incrementos radiais determinados por meio da média de quatro raios, diametralmente, opostos. As seqüências médias dos incrementos foram estandartizadas para salientar a variação a curto prazo. Os dados climáticos são oriundos da estação meteorológica do município de Santa Maria, RS. Foram calculadas grandezas climáticas compostas, como a evapotranspiração e o balanço hídrico, para melhor descrever as condições hídricas de crescimento das árvores. Foram determinados anéis de crescimento característicos e sensitividades das seqüências de crescimento. Possíveis mudanças no estado de competição das árvores e seu efeito no crescimento foram estudados. Além disso, foram relacionados o incremento radial e as variáveis climáticas selecionadas por intermédio de análise de correlação. Não foi possível identificar nenhuma variável climática que, coerentemente, tenha influenciado no incremento durante o período observado. Os resultados mostram que o excesso de água influencia no crescimento diamétrico das árvores.

  5. Evaluation of pollen production in Bromus catharticus Vahl and Guadua trinii (Nees Nees ex Rupr. (Poaceae for interpretation of fossil data

    Directory of Open Access Journals (Sweden)

    Jefferson Nunes Radaeski

    2016-12-01

    Full Text Available We evaluated pollen production per anther, per flower, and per spikelet of the grassland species Bromus catharticus and the forest taxon Guadua trinii (Poaceae, which have divergent pollination syndrome. We collected ten anthers of each taxon to determine differences in pollen production based on pollination system. Anthers were macerated and pollen grains were counted in a Neubauer chamber. Pollen morphology was observed using optical and scanning electron microscopy to establish relationships between pollen grain production and morphology. The anemophilous species Bromus catharticus (2,556,000 pollen grains/spikelet has twice the pollen production per anther and per spikelet compared to Guadua trinii (1,716,000 pollen grains/spikelet, a species that requires biotic assistance for pollination. Pollen grain size is inversely proportional to production. Microechinate ornamentation, which is not expected to occur in anemophilous species, was observed on pollen of both taxa. Our results indicate that the frequency of forest Poaceae in the quaternary records may be underestimated while frequency of grassland taxa may be overestimated, leading to misrepresentation of the respective flora in this period.

  6. Patienten met diabetes Mellitus type 1 screenen op coeliakie; Ja of nee

    NARCIS (Netherlands)

    Greijdanus, T.

    2005-01-01

    Diabetes mellitus type 1 is een veelvoorkomende ziekte. Deze ziekte blijkt niet op zichzelf te staan maar is onder andere geassocieerd met coeliakie. Coeliakie wordt behandeld middels een glutenvrij dieet. De diabetespatiënten die aan coeliakie lijden blijken zich niet altijd bij de huisarts met

  7. Antiinflammatory, Diuretic and Antimicrobial Activities of Rungia pectinata Linn. and Rungia repens Nees.

    Science.gov (United States)

    Swain, S R; Sinha, B N; Murthy, P N

    2008-09-01

    The hydroalcoholic extracts prepared from leaves of Rungia pectinata and Rungia repens were investigated for antiinflammatory and diuretic activity in wistar rats. The results obtained were compared with that of standard drug aspirin and frusemide for their antiinflammatory and diuretic activity respectively. The acute toxicity study was also carried out using adult swiss albino mice of either sex which indicates the safety of the extracts even at a dose of 4000 mg/kg. R. pectinata showed better anti-inflammatory activity than R. repens. In the present study, it was demonstrated that hydroalcoholic extracts of both R. repens and R. pectinata produce diuretic effect by increasing the excretion of Na(+), K(+) and Cl(-). Results showed that R. repens is most effective in increasing urinary electrolyte concentration of Na(+) and K(+) ions. The antimicrobial potency of the aerial parts of Rungia pectinata and Rungia repens have been studied using the petroleum ether, benzene, chloroform, acetone and ethanol extract against a wide number of bacteria and fungi by disc diffusion method. The ethanol extract at a concentration of 30 to 60 μg/disc showed significant activity against the bacteria and fungus investigated. All the extracts of R. pectinata and R. repens have got moderate action but chloroform and acetone extracts of R. repens and ethanol extract of R. pectinata have got significant activity against Trichophyton mentagrophytes.

  8. Leaf anatomic characterization of populations of Bromus auleticus Trin. Ex Nees (Poaceae

    Directory of Open Access Journals (Sweden)

    Miguel Dall’Agnol

    2008-09-01

    Full Text Available This work was carried out to characterize the leaf anatomy of eight Bromus auleticus populations collected in Rio Grande do Sul, Brazil, and called A5, A6, A8, A17, A23, A26 and A27. Totally expanded leaves were collected from plants in the vegetative stage and were sectioned and stained with basic fuchsine and alcian blue. A single layer of epidermis with a smooth and fine cuticle on both surfaces, short tricomes, vascular bundles in three sizes, and the presence of cells with lignified walls along the bundles and on the leaf edge were observed in all populations. The number of bulliform cells varied from three to five, with the exception of population A25, which ranged from five to eight cells. Three populations presented long tricomes (A6, A23 and A27 and palisade chlorenchyma (A6, A7 and A26, five had grooves on the leaf surface (A8, A17, A23, A26, A27 and homogeneous chlorenchyma (A5, A8, A17, A23, A27, two presented a large intercellular space in the mesofile (A7 and A17, and two showed a more visible cuticle on the abaxial surface (A7 and A8. These variations could reflect differences in relation to the nutritive value of the populations and be used in plant breeding programs for the genetic improvement of bromegrass.

  9. Analysis of the Anticancer Phytochemicals in Andrographis paniculata Nees. under Salinity Stress

    Science.gov (United States)

    Valdiani, Alireza; Maziah, Mahmood; Saad, Mohd Said

    2013-01-01

    Salinity causes the adverse effects in all physiological processes of plants. The present study aimed to investigate the potential of salt stress to enhance the accumulation of the anticancer phytochemicals in Andrographis paniculata accessions. For this purpose, 70-day-old plants were grown in different salinity levels (0.18, 4, 8, 12, and 16 dSm−1) on sand medium. After inducing a period of 30-day salinity stress and before flowering, all plants were harvested and the data on morphological traits, proline content and the three anticancer phytochemicals, including andrographolide (AG), neoandrographolide (NAG), and 14-deoxy-11,12-didehydroandrographolide (DDAG), were measured. The results indicated that salinity had a significant effect on the aforementioned three anticancer phytochemicals. In addition, the salt tolerance index (STI) was significantly decreased, while, except for DDAG, the content of proline, the AG, and NAG was significantly increased (P ≤ 0.01). Furthermore, it was revealed that significant differences among accessions could happen based on the total dry weight, STI, AG, and NAG. Finally, we noticed that the salinity at 12 dSm−1 led to the maximum increase in the quantities of AG, NAG, and DDAG. In other words, under salinity stress, the tolerant accessions were capable of accumulating the higher amounts of proline, AG, and NAG than the sensitive accessions. PMID:24371819

  10. A Classical Genetic Solution to Enhance the Biosynthesis of Anticancer Phytochemicals in Andrographis paniculata Nees

    Science.gov (United States)

    Talei, Daryush; Abdul Kadir, Mihdzar; Rafii, Mohd Yusop; Sagineedu, Sreenivasa Rao

    2014-01-01

    Andrographolides, the diterpene lactones, are major bioactive phytochemicals which could be found in different parts of the medicinal herb Andrographis paniculata. A number of such compounds namely andrographolide (AG), neoandrographolide (NAG), and 14-deoxy-11,12-didehydroandrographolide (DDAG) have already attracted a great deal of attention due to their potential therapeutic effects in hard-to-treat diseases such as cancers and HIV. Recently, they have also been considered as substrates for the discovery of novel pharmaceutical compounds. Nevertheless, there is still a huge gap in knowledge on the genetic pattern of the biosynthesis of these bioactive compounds. Hence, the present study aimed to investigate the genetic mechanisms controlling the biosynthesis of these phytochemicals using a diallel analysis. The high performance liquid chromatography analysis of the three andrographolides in 210 F1 progenies confirmed that the biosynthesis of these andrographolides was considerably increased via intraspecific hybridization. The results revealed high, moderate and low heterosis for DDAG, AG and NAG, respectively. Furthermore, the preponderance of non-additive gene actions was affirmed in the enhancement of the three andrographolides contents. The consequence of this type of gene action was the occurrence of high broad-sense and low narrow-sense heritabilities for the above mentioned andrographolides. The prevalence of non-additive gene action suggests the suitability of heterosis breeding and hybrid seed production as a preferred option to produce new plant varieties with higher andrographolide contents using the wild accessions of A. paniculata. Moreover, from an evolutionary point of view, the occurrence of population bottlenecks in the Malaysian accessions of A. paniculata was unveiled by observing a low level of additive genetic variance (VA) for all the andrographolides. PMID:24586262

  11. A study of seed production in Eragrostis curvula (Schrad.) Nees. | J ...

    African Journals Online (AJOL)

    Results are reported of a series of experiments designed to study the management of E. curvula for seed production in the Natal Region. The following are the main points which arose from this investigation: (a) approximately 90% of the seedheads present at harvest in December were produced by tillers which emerged in ...

  12. Trabajando el arteterapia con el alumnado con N.E.E (TDAH)

    OpenAIRE

    V??lez Borja, Eva

    2015-01-01

    Presentaci??n y descripci??n del Arteterapia en el aula a trav??s de diferentes actividades art??sticas hacia alumnos con ???TDAH?????? (Trastorno con D??ficit de Atenci??n con o sin Hiperactividad), donde se recogen los resultados para obtener una conclusi??n final, entendiendo como Arteterapia utilizar las creaciones art??sticas para mejorar el proceso de desarrollo de la persona. En el presente trabajo har?? menci??n a numerosos profesores e investigadores de la educaci??n y el arte que...

  13. Neonicotinoid-induced resurgence of rice leaffolder, Cnaphalocrocis medinalis (Guénee).

    Science.gov (United States)

    Chintalapati, Padmavathi; Katti, Gururaj; Puskur, Raghuveer Rao; Nagella Venkata, Krishnaiah

    2016-01-01

    Among the neonicotinoids, imidacloprid and thiamethoxam have been frequently used in planthopper endemic areas. Wherever leaffolder incidence occurs along with planthoppers in rice fields, use of neonicotinoids has resulted in increase in leaffolder population. The present study was carried out to verify and confirm the resurgence, as well as to identify factors contributing to resurgence. In imidacloprid- and thiamethoxam-applied plots, a 17.5-217.5% increase in leaffolder population over the untreated control was observed. Neonicotinoids showed moderate toxicity to eggs with 60% survival, while 37-60% of larvae reached adult stage. The larval duration was also reduced. Fecundity was stimulated, with a 6.2-37.21% increase over the untreated control. A significant positive correlation was observed between larval population and total soluble sugars in thiamethoxam treatment (r = 0.9984, P ≤ 0.01). Stimulated fecundity on neonicotinoid-sprayed plants, coupled with reduced larval duration and low egg toxicity, could be the major factors contributing to the upsurge of leaffolder. This study aids in cautioning farmers to be more vigilant while using imidacloprid and thiamethoxam, particularly in rice fields where leaffolder exists alongside planthoppers. © 2015 Society of Chemical Industry.

  14. Amauroderma rugosum (Blume & T. Nees Torrend: Nutritional Composition and Antioxidant and Potential Anti-Inflammatory Properties

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    Pui-Mun Chan

    2013-01-01

    Full Text Available Amauroderma rugosum is a wild mushroom that is worn as a necklace by the indigenous communities in Malaysia to prevent fits and incessant crying by babies. The aim of this study was to investigate the nutritive composition and antioxidant potential and anti-inflammatory effects of A. rugosum extracts on LPS-stimulated RAW264.7 cells. Nutritional analysis of freeze-dried mycelia of A. rugosum (KUM 61131 from submerged culture indicated a predominant presence of carbohydrates, proteins, dietary fibre, phosphorus, potassium, and sodium. The ethanol crude extract (EE, its hexane (HF, ethyl acetate (EAF, and aqueous (AF fractions of mycelia of A. rugosum grown in submerged culture were evaluated for antioxidant potential and anti-inflammatory effects. EAF exhibited the highest total phenolic content and the strongest antioxidant activity based on 2,2-diphenyl-1-picrylhydrazyl (DPPH and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS assays. HF showed dose-dependent inhibition of NO production in LPS-stimulated RAW264.7 cells and NO radical scavenging activity. Gas chromatographic analysis of HF revealed the presence of ethyl linoleate and ergosterol, compounds with known anti-inflammatory properties. In conclusion, the nutritive compositions and significant antioxidant potential and anti-inflammatory effects of mycelia extracts of A. rugosum have the potential to serve as a therapeutic agent or adjuvant in the management of inflammatory disorders.

  15. Diazepam (valium) als premedicatie bij keel- nees- oorheelkundige ingrepen onder locaal anesthesie

    NARCIS (Netherlands)

    Wesseling, Harm

    1972-01-01

    The study reported in this thesis began with the case history of a patient who died during an operation for nasas leptumcorrection. Deat was attributed to the local anaesthetic ussed, though many other drugs had also been given. This case report led us to look for a drug that could be used on its

  16. Andrographis paniculata (Burm. f. Wall. ex Nees: A Review of Ethnobotany, Phytochemistry, and Pharmacology

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    Md. Sanower Hossain

    2014-01-01

    Full Text Available As aboriginal sources of medications, medicinal plants are used from the ancient times. Andrographis paniculata is one of the highly used potential medicinal plants in the world. This plant is traditionally used for the treatment of common cold, diarrhoea, fever due to several infective cause, jaundice, as a health tonic for the liver and cardiovascular health, and as an antioxidant. It is also used to improve sexual dysfunctions and serve as a contraceptive. All parts of this plant are used to extract the active phytochemicals, but the compositions of phytoconstituents widely differ from one part to another and with place, season, and time of harvest. Our extensive data mining of the phytoconstituents revealed more than 55 ent-labdane diterpenoids, 30 flavonoids, 8 quinic acids, 4 xanthones, and 5 rare noriridoids. In this review, we selected only those compounds that pharmacology has already reported. Finally we focused on around 46 compounds for further discussion. We also discussed ethnobotany of this plant briefly. Recommendations addressing extraction process, tissue culture, and adventitious rooting techniques and propagation under abiotic stress conditions for improvement of phytoconstituents are discussed concisely in this paper. Further study areas on pharmacology are also proposed where needed.

  17. Ecologia da polinização de Raphiodon echinus (Nees & Mart. Schauer (Lamiaceae em Petrolina, PE, Brasil Pollination ecology of Raphiodon echinus (Nees & Mart. Schauer (Lamiaceae in Petrolina, Pernambuco State, Brazil

    Directory of Open Access Journals (Sweden)

    Carla Tatiana de Vasconcelos Dias

    2007-12-01

    Full Text Available Raphiodon echinus é uma espécie de hábito rasteiro, que ocorre espontaneamente em áreas de caatinga. No presente trabalho foram observados a biologia reprodutiva desta espécie com o objetivo de contribuir com informações sobre sua ecologia da polinização. As observações foram feitas em áreas de caatinga da Embrapa Semi-Árido, em Petrolina, PE. Para os experimentos de autopolinização espontânea, autopolinização manual, apomixia, geitonogamia, xenogamia, botões foram ensacados, emasculados e polinizados, quando necessário. Flores foram marcadas para estimar a polinização em condições naturais. Os visitantes florais foram observados das 7h30 min às 16h00, totalizando 45 horas de observações. As flores de R. echinus são infundibuliformes, de coloração violeta, exalam odor adocicado e estão reunidas em glomérulos. A antese é diurna, assincrônica, sendo mais freqüente no período da manhã, por volta das 07h00. A duração das flores é de aproximadamente 10 horas e cada inflorescência apresenta número variado de flores/dia. As flores são visitadas por abelhas e borboletas. Centris hyptidis foi responsável por 26% do total das visitas e, de acordo com o comportamento e freqüência de visitas, foi considerada como polinizador efetivo desta espécie. Quanto ao sistema de reprodução, R. echinus é autógama facultativa, produzindo frutos por autopolinização manual (70%, geitonogamia (63% e xenogamia (40%.Raphiodon echinus is a prostrate weedy species that occurs in the Caatinga. In this work, floral biology and reproductive system were observed in order to understand the pollination ecology of this species. Observations were made at Embrapa Semi-Árido, in Petrolina, Pernambuco. For the self-pollination, apomixis, geitonogamy and xenogamy experiments, buds were protected, emasculated, and pollinated when necessary. Flowers were tagged to estimate pollination success under natural conditions. Floral visitors were observed on different days from 7:30 a.m. to 4:00 p.m., for a total of 45 hours. The violet flowers of R. echinus are infundibuliform and give off a sweet scent; they are grouped in long-pedunculate spherical heads. Anthesis is diurnal and is more frequent in the morning around 7:00 a.m. Flowers last for about ten hours and the number of flowers that open daily on each inflorescence varies. The flowers are visited by bees and butterflies. Centris hyptidis was responsible for 26% of total visits. Based on behavior and frequency of visits, this bee was considered to be the effective pollinator of R. echinus. As regards the reproductive system, R. echinus is self-compatible and produces fruits by manual self-pollination (70%, geitonogamy (63% and xenogamy (40%.

  18. Estudo espectroscópico em elucidação estrutural de flavonoides de Solanum jabrense Agra & Nee e S. paludosum Moric Spectroscopy study on structural elucidation of flavonoids from Solanum jabrense Agra & Nee e S. paludosum Moric

    Directory of Open Access Journals (Sweden)

    Tania Maria Sarmento da Silva

    2009-01-01

    Full Text Available The NMR (RMN¹H, 13C, COSY, HMQC, HMBC, NOE-DIFF, NOESY and mass spectra data analysis of sixteen flavonoids, including nine natural, 7-O-methylkanferol (ramnocitrin, 3,7-di-O-methylkanferol (kumatakenin, 3-O-methylquercetin, 3,7,3',4'-tetra-O-methylquercetin (retusin, 3,7,8,4'-tetra-O-methylgossipetin, 3,7,8,3',4'-penta-O-methylgossipetin, 7-O-methylapigenin (genkwanin, 3,7,8-tri-O-methylherbacetin, 7,4'- di-O-methylquercetin (ombuine, isolated from Solanum paludosum and S. jabrense, and seven prepared methyl and acetyl derivatives, are discussed according the substitution on the rings A, B and C.

  19. Spectroscopy study on structural elucidation of flavonoids from Solanum jabrense Agra and Nee and S. paludosum Moric; Estudo espectroscopico em elucidacao estrutural de flavonoides de Solanum jabrense Agra and Nee e S. paludosum Moric

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Tania Maria Sarmento da [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Dept. de Quimica], e-mail: sarmento@pesquisador.cnpq.br; Carvalho, Mario Geraldo de [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Inst. de Ciencias Exatas. Dept. de Quimica; Braz-Filho, Raimundo [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacazes, RJ (Brazil). Setor de Quimica de Produtos Naturais

    2009-07-01

    The NMR (RMN{sup 1}H, {sup 13}C, COSY, HMQC, HMBC, NOE-DIFF, NOESY) and mass spectra data analysis of sixteen flavonoids, including nine natural, 7-O-methylkanferol (rhamnocitrin), 3,7-di-O-methylkanferol (kumatakenin), 3-O-methylquercetin, 3,7,3',4'-tetra-O-methylquercetin (retusin), 3,7,8,4'-tetra-O-methylgossipetin, 3,7,8,3',4'-penta-O-methylgossipetin, 7-O-methylapigenin (genkwanin), 3,7,8-tri-O-methylherbacetin, 7,4'- di-O-methylquercetin (ombuine), isolated from Solanum paludosum and S. jabrense, and seven prepared methyl and acetyl derivatives, are discussed according the substitution on the rings A, B and C. (author)

  20. Matemáticas: aprendizaje del alumnado con N.E.E. mediante el uso de materiales manipulativos

    OpenAIRE

    Zugasti Videgain, Adriana

    2017-01-01

    No cabe duda de que las Matemáticas son una ciencia compleja caracterizada principalmente por su abstracción. Esto provoca que, ya desde la etapa de Educación Primaria, los niños y niñas presenten dificultades para su aprendizaje. Concretamente, este trabajo se centra en el alumnado de Necesidades Educativas Especiales y dificultades de aprendizaje, quienes presentan dificultades mayores que el resto del alumnado para acceder a los aprendizajes que se determinan en el currículo...

  1. Quantification of Andrographolide Isolated from Andrographis paniculata Nees Obtained from Traditional Market in Yogyakarta Using Validated HPLC

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    Yandi Syukri

    2016-08-01

    Full Text Available This research was aimed to quantification of andrographolide isolated from A. paniculata Ness found in traditional market in Yogyakarta using validated HPLC to obtain high level content of andrographolide. The extraction of andrographolide from A. paniculata was carried out using ethanol as the solvent. Fractionation and isolation were continued using a non-polar solvent. Next, the extracts were re-crystallized to obtain isolated andrographolide. The identity of the compound was confirmed through an analysis of the melting point, IR spectra, and TLC. The purity of the compound was confirmed by the validated HPLC. The data obtained were then compared using an analytical grade of andrographolide as the standard. The isolated andrographolide confirmed melting point, IR spectra and TLC analysis were similar to the standard andrographolide. The method to determine the content of isolated andrographolide showed an adequate precision, with a relative standard deviation (RSD smaller than 1%. The accuracy showed good recovery values were obtained for all concentrations used. The HPLC method in this study showed specificity and selectivity with linearity in the working range and good precision and accuracy, making it very suitable for the quantification of andrographolide isolated in A. paniculata. When compared to the standard, the purity of the isolated andrographolide was 95.74 ± 0.29%.

  2. EFEK EKSTRAK SAMBILOTO (ANDROGRAPHIS PANICULATA NEES. PADA EKSPRESI P53 DARI KANKER PAYUDARA TIKUS YANG DIINDUKSI DMBA

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    Yurika Sastyarina

    2011-06-01

    Full Text Available ABSTRACT   It has been well documented that chemical carcinogen, 7.12 dimethylbenz-(aanthracene (DMBA,  plays a role in the incidence and growth of mammary cancer. Present study was designed to investigate the influence of Andrographis paniculata extract on telomerase activities on DMBA induced breast cancer in the female rat Sprague Dawley strain. DMBA-induced mammary cancer is a useful model to investigate the changes of epithelial cells that occur during mammary cancer progression. Mammary cancer model was induced 10 times twice a week by oral DMBA 20 mg/kg body weight. Mammary cancer occurred in 75 % animals nine weeks after oral administration of DMBA, it was represented with nodule on the mammary gland and the increasing of mammary gland volume compare with normal control F(1.8 = 731.711; p < 0.001. This study was also designed to investigate the effect of Andrographis paniculata extract mammary carcinoma induced by DMBA. Administration of three different dose of Andrographis paniculata (100 mg/kg, 300 mg/kg and 1000 mg/kg had statistically different with mammary gland volume of DMBA treated rat F (4.17 = 92.777; p<0.05. So, Andrographis paniculata has significant effect on the treatment of DMBA-induced mammary carcinoma. The Epithelial cells were harvested on day 90 and stained with routine histology staining, hematoxylineosin, for morphological qualitative analysis, immunohistochemical examination. The lesions observed from the removed samples ranged widely from benign to malignant. The results showed that DMBA induce cell proliferation, nuclear irregularities, and numerous mitoses and induced cell necrosis. On immunohistochemical examination, it shows that Andrographis paniculata can stimulate of expression of p53 protein and increase the number of epithelial cells experience apoptosis.   Key words: Sambiloto (Andrographis Paniculata Ness, DMBA, mammary cancer, p53     ABSTRAK   Telah terdokumentasi dengan baik bahwa karsinogen kimia, 7,12 dimetilbenz(aantrasena (DMBA, berperan dalam kejadian dan perkembangan kanker payudara. Penelitian ini dirancang untuk mengetahui pengaruh ekstrak Andrographis paniculata ekspresi p53 dan apoptosis pada kanker payudara tikus strain Sprague Dawley yang diinduksi DMBA. Kanker Payudara yang diinduksi DMBA adalah sebuah model yang berguna untuk mengetahui perubahan sel epitel yang terjadi selama perkembangan kanker payudara. Model Kanker Payudara diinduksi DMBA secara per oral 20 mg / kg 10 kali yaitu dua kali seminggu. Kanker Payudara terjadi pada 75% hewan pada sembilan minggu setelah pemberian oral DMBA, Hal itu diwakili dengan benjolan pada kelenjar susu dan meningkatnya volume kelenjar susu dibandingkan dengan F kontrol (1,8 = 731.711; p <0,001. Penelitian ini juga dirancang untuk mengetahui pengaruh ekstrak Andrographis paniculata pada kanker payudara yang diinduksi oleh DMBA. Pada pemeriksaan imunohistokimia, hal itu menunjukkan bahwa sambiloto dapat menurunkan enzim telomerase, meningkatkan ekspresi protein p53 dan meningkatkan jumlah apoptosis sel epitel.   Kata Kunci: Sambiloto (Andrographis Paniculata. Ness, DMBA, Kanker payudara, p53

  3. Biomasa acumulada e indicadores de calidad nutritiva en cebadilla chaqueña (Bromus auleticus Trinius ex Nees

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    BUSTAMANTE, E.G.R.

    2012-06-01

    Full Text Available Bromus auleticus (cebadilla chaqueña es considerada uno de los recursos forrajeros más promisorios delCono Sur. Presenta variación entre poblaciones que ha sido determinada para diversos caracteres vegetativos, lo cual podría traducirse en diferencias de producción y calidad de forraje. El objetivo del presente estudio fue evaluar dos procedencias de cebadilla chaqueña (Argentina y Uruguay para biomasa acumulada e indicadores de calidad nutritiva en dos períodos del año (verano-otoño y otoño-primavera. Se compararon cinco clones uruguayos (U y cinco argentinos (A, dispuestos al azar en surcos distanciados a 1 m entre sí, con 10 plantas cada uno. Se determinó biomasa acumulada por planta (B y calidad, midiendo Fibra Detergente Neutra (FDN, Proteína Bruta (PB y Digestibilidad de la Materia Seca (DMS en dos momentos del año. En general, la biomasa fue de baja calidad debido al momento en que se realizaron los cortes, lo que limita elalcance de los resultados. Sin embargo, las diferencias observadas entre los clones en este estado de desarrollo podrían indicar la existencia de variación entre genotipos de cebadilla chaqueña U y A en biomasa y calidad nutritiva. En biomasa acumulada no se observó efecto significativo de origen. En todas las variablesde calidad evaluadas en verano-otoño, se encontraron diferencias significativas entre orígenes. En otoñoprimavera, las diferencias entre orígenes fueron significativas para DMS. Los clones U presentaron mayor PB, menor FDN y mayor DMS. Dentro de cada origen, los argentinos presentaron menos diferencias que los uruguayos, tanto en biomasa acumulada como en calidad. Para ninguno de los clones A o U se encontró coincidencia entre mayor biomasa y mayor calidad.

  4. Antimicrobial activity and composition of the volatiles of Cinnamomum tamala Nees. and Murraya koenigii (L. Spreng. from Uttarakhand (India

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    Manindra Mohan

    2012-05-01

    Full Text Available Objective: To examine the composition of Cinnamomum tamala and Murraya koenigii essential oils and their antimicrobial activities against nine microbial strains. Methods: Essential oils were obtained by hydrodistillation from the leaves of two spice trees and were analyzed by GC and GC/MS. The oils were also tested for their antimicrobial activity using broth micro dilution method. Results: Cinnamaldehyde (37.85% and cis-linalool oxide (29.99% were the main components characterized in the oil of C. tamala, whereas α -pinene (39.93%, sabinene (13.31% and trans-caryophyllene (9.02% detected as the major constituents in M. koenigii oil. C. tamala oil exhibited significant antifungal activity and satisfactory antibacterial activity, while lesser antimicrobial activity was observed in M. koenigii oil. Conclusions: The present study suggested that C. tamala oil was more effective against bacterial and fungal strains as compared with M. koenghii oil.

  5. Increased delignification rate of Dendrocalamus strictus (Roxburgh nees by Schizophyllum commune Fr.; Fr. to reduce chemical consumption during pulping process

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    Vipin Kumar Saini

    2013-08-01

    Full Text Available Pulp and paper industry is traditionally known to be a large contributor to environmental pollution due its largeconsumption of energy and chemicals. To reduce the chemical consumption, rate of delignification was increased bySchizophyllum commune in destructured sample of Dendrocalamus stictus, which was destructured by Impressafiner (compression-cum dewatering process. The extent of delignification was determined and comparison was made between thenon-destructured and destructured samples. The influence of physical parameters like incubation time, moisture level, media,media concentration, pH and temperature were also examined during the study. It was found that rate of delignification wassignificantly 6.43% more in destructured sample than non-destructured sample. Kraft pulping of treated destructured sampleshows 2.59 point reduction in kappa number than untreated non-destructured sample. Thus this paper provides an insight ofthe delignification extent in Dendrocalamus strictus after mechanical operation at varying physical parameters.

  6. Inhibitory actions of Pseuderanthemum palatiferum (Nees Radlk. leaf ethanolic extract and its phytochemicals against carbohydrate-digesting enzymes

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    Pawitra Pulbutr

    2016-02-01

    Conclusions: These results indicate an inhibitory action against carbohydrate-digesting enzymes as the anti-diabetic mechanism of action of PPE. Nonetheless, further clinical study is required to justify its role in the treatment of diabetes.

  7. Validation of a method for the determination of sterols and triterpenes in the aerial part of Justicia anselliana (Nees) T. Anders by capillary gas chromatography.

    Science.gov (United States)

    Kpoviéssi, Dossou Sika Salomé; Gbaguidi, Fernand; Gbénou, Joachim; Accrombessi, Georges; Moudachirou, Mansourou; Rozet, Eric; Hubert, Philippe; Quetin-Leclercq, Joëlle

    2008-12-01

    An accurate and sensitive method, combining soxhlet extraction, solid phase-extraction and capillary gas chromatography is described for the quantitative determination of one triterpene (lupeol) and three sterols (stigmasterol, campesterol and beta-sitosterol) and the detection of another triterpene (alpha-amyrin) from the aerial part of Justicia anselliana. This is the first method allowing the quantification of sterols and triterpenes in this plant. It has been fully validated in order to be able to compare the sterol and triterpene composition of different samples of J. anselliana and therefore help to explain the allelopathic activity due to these compounds. This method showed that the aerial part of J. anselliana contained (292+/-2)mg/kg of lupeol, (206+/-1)mg/kg of stigmasterol, (266+/-2)mg/kg of campesterol and (184+/-9)mg/kg of beta-sitosterol.

  8. Improving Hatchery Effectiveness as Related to Smoltification: Proceedings of a Workshop held at Kah-Nee-Tah Lodge, Warm Springs, Oregon, May 20-23, 1985.

    Energy Technology Data Exchange (ETDEWEB)

    Bouck, Gerald R.

    1987-05-01

    The Bonneville Power Administration (BPA) intends to develop a smoltification research effort that would have broad support among the interested parties. BPA sponsored this workshop on smoltification and related research to gather leading technical experts in the field in smoltification, permit them to exchange information about the state of the art of smoltification research, and allow them to identify and rank high-priority projects. This document includes keynote speeches, technical papers, and other sessions that summarize both what is known and what information is needed.

  9. Salmonella and fecal coliforms in cinnamon (Cinnamomum cassia Blume and Cinnamomum zeylanicum Nees) sold in the city of Florianópolis, Santa Catarina, Brazil

    OpenAIRE

    Philippi, Jane Maria de S.; Moretto, Eliane

    1995-01-01

    Cem amostras de canela em pó de dez marcas diferentes comercializadas na cidade de Florianópolis, SC, foram submetidas à análise microbiológica, pesquisando-se Salmonella e coliformes de origem fecal. Em nenhuma amostra foi detectada Salmonella. Coliformes de origem fecal foram encontrados entre os valores

  10. Caracterização anatômica da lâmina foliar de populações de Bromus auleticus Trin. Ex Nees (Poaceae

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    Cercí Maria Carneiro

    2008-01-01

    Folhas totalmente expandidas foram coletadas de plantas em estádio vegetativo, seccionadas e coradas com fucsina e azul de Alcian. Verificou-se em todas as populações a presença de epiderme uniestratificada, com cutícula lisa e delgada em ambas as faces, tricomas curtos, feixes vasculares de três tamanhos e células com parede lignificada junto aos feixes e no bordo foliar. O número de células buliformes varia de três a cinco, com exceção da população A26, com cinco a oito células. Três populações possuem tricomas longos (A6, A23, A27 e clorênquima em paliçada (A6, A7, A26, cinco exibem sulcos na superfície foliar (A8, A17, A23, A26, A27 e clorênquima homogêneo (A5, A8, A17, A23, A27, duas apresentam amplos espaços intercelulares no mesofi lo (A7, A17 e duas, cutícula mais evidente na face abaxial (A7, A8. Essas variações podem refletir diferenças no valor nutritivo das populações e serem exploradas nos trabalhos de melhoramento genético da cevadilha vacariana.

  11. Germinação in vitro de eixos embrionários zigóticos de imbuia (ocotea porosa (NEES EX MARTIUS Liberato Barroso

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    Luciana Luiza Pelegrini

    2013-04-01

    Full Text Available A imbuia apresenta sementes recalcitrantes, com forte dormência tegumentar, irregularidade e baixa germinação, dificultando sua propagação natural. O objetivo deste trabalho foi avaliar a germinação in vitro de eixos embrionários de imbuia, testando o efeito de diferentes concentrações de sacarose, de carvão ativado e de formulações salinas para acelerar a produção de mudas. Eixos embrionários zigóticos foram inoculados em meio de cultura MS/2 contendo diferentes concentrações de sacarose (15, 30, 60 ou 90 g L-1, de carvão ativado (0, 1, 2 ou 3 g L-1 e diferentes formulações salinas (MS, WPM, MS/2 ou WPM/2. Os resultados indicaram que a adição de 15 g L-1 de sacarose foi insuficiente para promover a germinação dos eixos embrionários e as demais concentrações promoveram entre 45,5 e 59,4% de germinação. Com relação às formulações salinas, os melhores resultados foram obtidos com os meios de cultura MS e MS/2 obtendo-se 67,7 e 74,2% de germinação, respectivamente. A adição de carvão ativado favoreceu a germinação in vitro dos eixos embrionários, enquanto que na ausência de carvão ativado não ocorreu germinação e houve elevada porcentagem de oxidação. A germinação in vitro de imbuia é viável e pode ser obtida com eixos embrionários zigóticos maduros com a formulação salina MS/2, suplementada com 30 g L-1 de sacarose e 1g L-1 de carvão ativado.

  12. Antimicrobial Activity and Modulatory Effect of Essential Oil from the Leaf of Rhaphiodon echinus (Nees & Mart Schauer on Some Antimicrobial Drugs

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    Antonia Eliene Duarte

    2016-06-01

    Full Text Available Background: Rhaphiodon echinus is a weed plant used in the Brazilian folk medicinal for the treatment of infectious diseases. In this study, the essential oil of R. echinus leaf was investigated for its antimicrobial properties. Methods: The chemical constituents of the essential oil were characterized by GC-MS. The antimicrobial properties were determined by studying by the microdilution method the effect of the oil alone, and in combination with antifungal or antibiotic drugs against the fungi Candida albicans, Candida krusei and Candida tropicalis and the microbes Escherichia coli, Staphylococcus aureus and Pseudomonas. In addition, the iron (II chelation potential of the oil was determined. Results: The results showed the presence of β-caryophyllene and bicyclogermacrene in major compounds, and revealed a low antifungal and antibacterial activity of the essential oil, but a strong modulatory effect on antimicrobial drugs when associated with the oil. The essential oil showed iron (II chelation activity. Conclusions: The GC-MS characterization revealed the presence of monoterpenes and sesquiterpenes in the essential oil and metal chelation potential, which may be responsible in part for the modulatory effect of the oil. These findings suggest that essential oil of R. echinus is a natural product capable of enhancing the antibacterial and antifungal activity of antimicrobial drugs.

  13. Integración de los niños y niñas con NEE: superdotación y autismo

    OpenAIRE

    Pérez Ordoño, Yoana

    2014-01-01

    En España y en otros muchos países la educación ha sufrido grandes cambios, ya sea en la educación ordinaria como en el tratamiento de la atención a la diversidad. Este trabajo pretende analizar esta evolución, así como otros aspectos importantes que repercuten directamente en como se aborda este tema en los centros educativos. Ademas, de proponer diferentes propuestas para ayudar al profesorado en el tratamiento de las diferentes necesidades educativas especiales, más concreta...

  14. Nutrient analysis of Kunapa jala and Pancha gavya and their evaluation on germination of Ashwagandha (Withania somnifera Dunal) and Kalamegha (Andrographis paniculata Nees.) seeds: A comparative study.

    Science.gov (United States)

    Ankad, Gireesh M; Hiremath, Jagadishchandra; Patil, R T; Pramod, H J; Hegde, Harsha V

    2017-11-10

    Vrikshayurveda, an ancient science of plant life described by Surapala, deals with healthy growth and productivity of plants, which has clearly outlined a systematized agricultural practice that insisted the use of Kunapa jala (KJ) and Pancha gavya (PG). An experiment was conducted to validate KJ and PG by nutrient analysis and their effect on the germination parameters of Ashwagandha and Kalamegha seeds in comparison with other treatment groups. KJ and PG were prepared according to the classical references. The nutrient contents and germination parameters of KJ and PG were compared with other groups namely control (Contr), farmyard manure (FYM), humic acid (HA) and NPK. The pH and EC were 5.793, 2.653 dS/m and 5.584, 2.216 dS/m for KJ and PG respectively. KJ possess highest nutrient contents followed by PG. The germination parameters revealed the better activity of NPK followed by KJ, PG, HA, FYM and Contr. KJ and PG were found to be good in nutrient contents and were found to be effective on studied germination parameters of Ashwagandha and Kalamegha seeds. Copyright © 2017 Transdisciplinary University, Bangalore and World Ayurveda Foundation. Published by Elsevier B.V. All rights reserved.

  15. Analyzing the Interaction of Andrographolide and Neoandrographolide, Diterpenoid Compounds From Andrographis Paniculata (Burm.F Nees, to Cyclooxygenase-2 Enzyme by Docking Simulation

    Directory of Open Access Journals (Sweden)

    Jutti Levita

    2009-09-01

    Full Text Available Cyclooxygenase (COX, an enzyme involved in the conversion of arachidonic acid to prostaglandins, exists in two isoforms, which are COX-1 and COX-2. Despite the similarities of COX-1 and COX-2, the two isoforms show subtle differences in amino acid composition at the active sites. Since COX-1 has isoleucine, a bulkier amino acid at position 523 than COX-2’s valine, it allows COX-2 to have a larger space in its active site. Andrographolide reduces COX-2 expression induced by PAF and fMLP in HL60/neutrophils. Neoandrographolide inhibits COX-2 expression at the translational level. The purpose of this study is to examine the binding modes of andrographolide and neoandrographolide against COX-1 and COX-2 in terms of hydrogen bonds and docking energy, to understand their antiinflammatory property. The docking study indicates that both andrographolide and neoandrographolide are able to be located in the COX-2’s binding pocket but not in the COX-1’s. It confirms that COX-1’s binding pocket is smaller than COX-2’s. Based on this study, both andrographolide and neoandrographolide show selective inhibitory property to COX-2. Their selectivity are due to their specific interaction with Arg 513 in the binding pocket of COX-2, which is also shown by SC-558, a COX-2 selective inhibitor.

  16. Recovery of lignin peroxidase from submerged liquid fermentation of Amauroderma rugosum (Blume & T. Nees) Torrend using polyethylene glycol/salt aqueous two-phase system.

    Science.gov (United States)

    Jong, Wan Yng Linda; Show, Pau Loke; Ling, Tau Chuan; Tan, Yee Shin

    2017-07-01

    Amauroderma rugosum is a wild mushroom species widely distributed in tropics and is classified under the class of Basidiomycetes. Basidiomycetes are well-known for their abilities of producing lignocellulolytic enzymes such as lignin peroxidase (LiP), laccase (Lac) and manganese peroxidase (MnP). Different factors such as nutrient sources, incubation period and agitation affect the production of lignocellulolytic enzymes. The A. rugosum produced LiP in the medium supplemented with potato dextrose broth (PDB), 0.5% yeast and 1.0% saw dust at 26.70±3.31 U/mL. However, the LiP activity was increased to 106.32±5.32 U/mL when supplemented with 150 μm of copper (CuSO4). The aqueous two-phase system (ATPS) is a simple, rapid and low cost method for primary extraction and recovery of LiP. A total of 25 systems made from five different molecular weights of polyethylene glycol (PEG)/dipotassium hydrogen phosphate (K2HPO4) were tested. PEG 600 produced the highest top phase purification factor (PFT) of 1.33±0.62 with yield of 72.18±8.50%. The optimization of the ATPS parameters, such as volume ratio VR, pH and crude enzyme loading are the factors controlling the phase partition. Our results showed that significant improvement (PFT of 6.26±2.87 with yield of 87.31±3.14%) of LiP recovery can be achieved by optimized the parameters. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. POTENSI ANTI-HIPERKOLESTEROLEMIA EKASTRAK CASSIA VERA [Anti-hypercholesterolemic Potency of Cassia Vera (Cinnamomum burmanni Nees ex Blume Bark Extract

    Directory of Open Access Journals (Sweden)

    Fauzan Azima1

    2004-08-01

    Full Text Available There has been limited report on the phytochemical content of cassia vera bark extract, and its potency as anti-hypercholesterolemic in rabbit is not known yet. The objectives of this research was to determine the phytochemical content and potency of anti-hypercholesterolemic of cassia vera bark extract using rabbit as the animal model.The research was devided into three stages, namely: (1 preparing cassia vera extraction with ethanol 96%; (2 analyzing phytochemical contents of cassia vera bark extract; (3 in vivo experiment, where twenty New Zealand White rabbits aged 5 months were used. Experimental rabbits were divided into 5 groups. The rabbits were fed with atherogenic cholesterol (0.1% as positive control, RB11 standard feed as negative control, or cassia vera extracts (100 mg/kg/day or 200 mg/kg/day or fenofibrat (15 mg/day together with the atherogenic feed for 12 weeks. Levels of serum total cholesterol, triglyceride, HDL-cholesterol and LDL-cholesterol were determined at 0, 4, 8, and 12 week. At the end of the experiment formation of fatty liver were observed. The results showed that the ethanol extract of cassia vera bark contains total phenol (62.25%, flavonoids, triterpenoid, saponin and alkaloid. On the other hand, cassia vera bark extract was able to decrease total serum cholesterol from 443.3 mg/dl to 139.1 mg/dl, LDL cholesterol from 286.5 mg/dl to 95.8 mg/dl and triglyceride from 122.2 mg/dl to 61.2 mg/dl. Meanwhile, it increased HDL serum cholesterol from 29.1 mg/dl to 50.0 mg/dl in rabbit. It was also shown that the extract was able to decrease the everage fat globule on liver significantly from 27.47 globule to 3.59 globule per field view. Cassia vera bark extract with phytochemical content was found to be potential as anti-hypercholesterolemic and also in preventing fatty liver formatonr in rabbit

  18. New form of China aster (Callistephus chinensis (L. Nees. Structure and biology of ray florets with open tubular corollas (type RO

    Directory of Open Access Journals (Sweden)

    Alicja Wosińska

    2013-12-01

    Full Text Available A radiomutant of China aster with a new type of head and new type of ray florets was described. All florets in the head were bisexual and tubular although dimorphic - they varied in size and colour. The place of ray florets in the head was taken by bisexual open tubular florets which were often crowned with irregular teeth. Disc florets were short and parchment-like. In both types of florets the following were compared: number and size of stamens, vitality of pollen and floret fertility. A number of teeth (lobes in the corolIas of disc florets was also determined. Attention was also paid to the frequently observed anomalies and in particular to stamen displation. The problem is discussed of whether the obtained form resulted from mutation of disc florets with the simultaneous mutation of factors determining the so far unknown in China aster the head type without the whorl ofray florets or whether it was a mutation of ray flowers (corolla type and androecium formation. The author presents the opinion that the form resulted from the mutation ligulate of ray florets to the type of florets described above.

  19. Gonatocerus Nees (Hymenoptera, Mymaridae no centro do Estado do Rio Grande do Sul, Brasil: Novos registros e chave de identificação

    Directory of Open Access Journals (Sweden)

    Marina Rauber

    2016-08-01

    Abstract. Among the species of Hymenoptera, the parasitoids represent an important element of Neotropical fauna for his role in population control agricultural pests in biological control programs. Members of Mymaridae are idiobiont parasitoids of insect eggs. Mimarides of Gonatocerini have great agricultural importance, because some species are used in biological control of Proconiini (Hemiptera: Cicadellidae. Currently have 14 known genera. The necessity of taxonomic works at the species level has prevented their application in biological control programs in tobacco. With that, the objective of this study was to identify parasitoid wasps of Gonatocerini deposited in the Entomological Collection of Santa Cruz do Sul (CESC, collected through entomological traps of Malaise and Pitfall in tobacco crops with organic and conventional management systems and, subsequently develop an identification key to the species found. It were identified 698 individuals in 21 different species, belonging to four genera of Gonatocerini, being Gonatocerus hasthe largest number of individuals, with 475, followed by Cosmocomoidea, with 141, Lymaenon, with 72 and Tanyxiphium, with only 10 individuals, where 84% were collected in organic cultivation of crops and only 16% in conventional management. The most abundant species was Gonatocerus granulosus (Ogloblin, 1959, with 252 individuals. Of the 21 species found, 13 still lack record for Brazil.

  20. Seismic Risk Reduction for Soft-Story Wood-Frame Buildings: Test Results and Retrofit Recommendations from the Nees-Soft Project

    Science.gov (United States)

    John W. van de Lindt; Pouria Bahmani; Mikhail Gershfeld; Gary Mochizuki; Xiaoyun Shao; Steven E. Pryor; Weichiang Pang; Michael D. Symans; Jingjing Tian; Ershad Ziaei; Elaina N. Jennings; Douglas Rammer

    2014-01-01

    There are thousands of soft-story wood-frame buildings in California which have been recognized as a disaster preparedness problem with concerted mitigation efforts underway in many cities throughout the state. The vast majority of those efforts are based on numerical modelling, often with half-century old data in which assumptions have to be made based on engineering...

  1. Hubungan antara Konsentrasi Minyak Atsiri Kayu Manis (Cinnamomum burmannii Nees Ex Bl. dalam Lotion dengan Sifat Fisik dan Tingkat Kesukaan Konsumen

    Directory of Open Access Journals (Sweden)

    Erwan Kurnianto

    2017-07-01

    Full Text Available ABSTRACT Essential oil of Cinnamomum burmannii contains cinnamaldehyde as active substance as antibacterial and repellant. The study about development of dosage forms was needed in order be useful to people. The purpose of this study was to determine the concentration’s effect of cinnamon to the physical characteristic and results hedonic test of lotion. This study was done in Laboratory of Pharmacy UAD in 2014 that was begun with distillation of essential oil. Then, it was formulated as lotion with concentration 1% (F1, 3% (F II, 5% (F III, 7% (F IV, respectively. The lotion was evaluated its physical characteristic (homogeneity, viscosity, spreadability, adhesivity, pH and hedonic test to know the level of acceptability based on colour and flavor of lotion. Data was collected  by  quistionnaire. Results of study showed that all of the lotion was homogenous. The increasing concentrations of cinnamon caused decreasing of viscosity (p <0.05 and adhesivity (P <0.05, an increasing of spreadability (P <0.05, did not affect the pH value (p> 0.05, and increasing hedonic level until 5% concentration. It can be concluded that concentration of essential oil of cinnamon at 5% fullfilled the requirement of spreadability, adhesivity, pH  and the most prefered by consumers. Minyak atsiri kayu manis dengan kandungan bahan aktif cinnamaldehyde telah terbukti berkhasiat sebagai antibakteri dan repelan. Penelitian terkait pengembangan bentuk sediaan diperlukan agar dapat dimanfaatkan oleh masyarakat. Tujuan penelitian ini adalah mengetahui pengaruh konsentrasi minyak atsiri kayu manis dalam lotion terhadap sifat fisik dan tingkat kesukaan konsumen. Penelitian ini dilaksanakan di Laboratorium Farmasi UAD tahun 2014 dengan rancangan eksperimental yang diawali dengan destilasi minyak atsiri kayu manis. Selanjutnya minyak atsiri diformulasikan dalam bentuk lotion dengan konsentrasi 1% (F1, 3% (F II, 5% (F III, 7% (F IV. Sediaan lotion diuji sifat fisik (homogenitas, viskositas, daya sebar, daya lekat, pH dan uji hedonik untuk mengetahui tingkat kesukaan konsumen berdasarkan warna dan aroma lotion. Data tersebut diperoleh dengan memberikan kuisioner kepada 30 orang peserta. Hasil uji menunjukkan bahwa lotion homogen pada semua konsentrasi. Peningkatan konsentrasi minyak atsiri kayu manis menyebabkan penurunan viskositas (p<0,05 dan  daya lekat (P<0,05, peningkatan daya sebar (P<0,05, tidak mempengaruhi nilai pH (p>0,05 serta peningkatan skor hedonik sampai pada konsentrasi 5%. Berdasarkan hasil uji maka dapat disimpulkan bahwa konsentrasi minyak atsiri kayu manis sebesar 5% memenuhi persyaratan daya sebar, daya lekat, pH dan paling disukai oleh konsumen.

  2. Fusarium lateritium (NEES) as an agent of fungemia in a patient infected with the human immunodeficiency virus (HIV) Fusarium lateritium (NEES) como agente de fungemia em um paciente infectado com o vírus da imunodeficiência humana (HIV)

    National Research Council Canada - National Science Library

    Idalina Inês Fonsêca Nogueira Cambuim; Rejane Pereira Neves; Lusinete Aciole de Queiroz; Oliane Maria Correia Magalhães; Débora Maria Massa Lima

    2007-01-01

    .... The association of fungi from the Fusarium genus with human infection in uncommon. The objective of this paper is to report the first case of fungaemia caused by Fusarium lateritium in a 42-year-old HIV-infected patient.Patógenos...

  3. When hummingbirds are the thieves: visitation effect on the reproduction of Neotropical snowbell Styrax ferrugineus Nees & Mart (Styracaceae Quando os beija-flores são os ladrões: efeito da visitação na reprodução de uma planta Neotropical Styrax ferrugineus Nees & Mart (Styracaceae

    Directory of Open Access Journals (Sweden)

    Pietro Kiyoshi Maruyama

    2012-03-01

    Full Text Available The spectrum of floral visitors associated with a particular plant is frequently larger than predicted by the traditional concept of floral syndromes and the role that unpredicted visitors play in plant reproduction deserves attention. Hummingbirds are frequently recorded visiting flowers with distinct floral syndromes, especially in some hummingbird flower poor ecosystem such as the Cerrado. In this study we investigated the effect of frequent hummingbird visits on the reproduction of melittophilous Styrax ferrugineus. The flowers were visited by many different insect groups and visits by hummingbirds were frequent, especially early in the morning when nectar availability was higher. Nectar parameters varied considerably during the flower life span, and was probably affected by the temperature variation during the day. Hummingbird exclusion experiments showed no effect in the fruit-set of the plant. The inability of hummingbirds to deplete all of the nectar produced in this mass-flowering plant, and the existence of another resource (pollen for the primary pollinator (large bees, are possible reasons why there was no perceptible hindrance of plant reproduction by the hummingbirds. Although no effect in the fruit-set was observed, the use of non-ornithophilous flowers must be important for hummingbirds, which are specialized nectar consumers.O espectro de visitantes florais associados a uma planta é frequentemente maior que o esperado pelo conceito tradicional de síndromes florais e o papel desses visitantes inesperados tem recebido mais atenção. Os beija-flores freqüentemente visitam flores com síndromes florais distintas, especialmente em alguns ecossistemas pobre em flores ornitófilas como o Cerrado. Investigamos aqui o efeito das visitas de beija-flores na reprodução de Styrax ferrugineus, uma espécie melitófila. As flores foram visitadas por diferentes grupos de insetos e as visitas por beija-flores foram frequentes, especialmente no início das manhãs quando a disponibilidade de néctar foi maior. Os parâmetros de néctar variaram consideravelmente durante a antese, provavelmente afetados pela variação da temperatura durante o dia. Experimentos de exclusão de beija-flores não mostraram efeito sobre a produção de frutos. A incapacidade dos beija-flores em esgotar todo néctar produzido pela planta e a existência de outro recurso floral (pólen para o polinizador principal (grandes abelhas são apontadas como razões possíveis para a ausência desse efeito. Embora não tenha sido observado efeito sobre a produção de frutos, o uso de flores não ornitófilas deve ser importante para os beija-flores que são consumidores especializados de néctar.

  4. Enfoque metacognitivo en la investigación pedagógica de la comprensión lectora en alumnos con N.E.E. : teoría en la práctica

    OpenAIRE

    Reyes Rebollo, Miguel María; Barrero González, Narciso

    2001-01-01

    En este artículo se estudia el enfoque metacognitivo de la investigación pedagógica en los procesos de comprensión lectora. Esta línea se incluye en el paradigma mediacional centrado en el alumno que constituye un puente entre las concepciones proceso-producto y la ecología de aula, constituyendo una fusión de lo cognitivo con aspectos motivacionales. Esta nueva forma de enfocar la investigación puede considerarse como un modelo teórico interpretativo para el diseño general de la enseñanza, p...

  5. FINAL REPORT: EDDY-COVARIANCE FLUX TOWER AND TRACER TECHNOLOGY SUPPORT FOR THE UNIVERSITY OF GEORGIA PROPOSAL: FROM TOWER TO PIXEL: INTEGRATION OF PATCH-SIZE NEE USING EXPERIMENTAL MODELING FOOTPRINT ANALYSIS.

    Energy Technology Data Exchange (ETDEWEB)

    LEWIN,K.F.; NAGY, J.; WATSON, T.B.

    2007-09-01

    Brookhaven National Laboratory has been funded since October of 2000 to provide assistance to the University of Georgia in conducting footprint analyses of individual towers based on meteorology and trace gas measurements. Brookhaven researchers conducted air flow measurements using perfluorocarbon tracers and meteorological instrumentation for three experimental campaigns at an AmeriFlux research site maintained by Dr. Monique Leclerc near Gainesville, FL. In addition, BNL provided assistance with remote data collection and distribution from remote field sites operated by Dr. John Hom of the US Forest Service in the Pine Barrens of New Jersey and at FACE research sites in North Carolina and Wisconsin.

  6. Ocorrência de Salmonella e coliformes de origem fecal na canela em pó (Cinnamomum cassia Blume a Cinnamomum zeylanicum Nees) comercializada em Florianópolis, Santa Catarina, Brasil

    OpenAIRE

    Philippi Jane Maria de S.; Moretto Eliane

    1995-01-01

    Cem amostras de canela em pó de dez marcas diferentes comercializadas na cidade de Florianópolis, SC, foram submetidas à análise microbiológica, pesquisando-se Salmonella e coliformes de origem fecal. Em nenhuma amostra foi detectada Salmonella. Coliformes de origem fecal foram encontrados entre os valores

  7. Ocorrência de Salmonella e coliformes de origem fecal na canela em pó (Cinnamomum cassia Blume a Cinnamomum zeylanicum Nees comercializada em Florianópolis, Santa Catarina, Brasil

    Directory of Open Access Journals (Sweden)

    Philippi Jane Maria de S.

    1995-01-01

    Full Text Available Cem amostras de canela em pó de dez marcas diferentes comercializadas na cidade de Florianópolis, SC, foram submetidas à análise microbiológica, pesquisando-se Salmonella e coliformes de origem fecal. Em nenhuma amostra foi detectada Salmonella. Coliformes de origem fecal foram encontrados entre os valores <3 a 2.400 NMP/g. Das amostras analisadas, 63% apresentaram valores de <3 NMP/g; 34% apresentaram valores entre 3 e 100 NMP/g, limite este permitido pela legislação brasileira em vigor; e 3% apresentaram valores superiores a 100 NMP/g. A presença de coliformes de origem fecal foi detectada em 37% das amostras de canela em pó.

  8. Protective effects of methanolic extract of Adhatoda vasica Nees leaf in collagen-induced arthritis by modulation of synovial toll-like receptor-2 expression and release of pro-inflammatory mediators

    Directory of Open Access Journals (Sweden)

    Rana Adhikary

    2016-03-01

    Full Text Available RA associated with oxidative stress and chronic inflammation has been a major health problem among the population worldwide. In this study protective effect of methanolic extract of Adhatoda vasica leaf (AVE was evaluated on Collagen-induced arthritis in male Swiss albino mice. Post oral administration of AVE at 50, 100 and 200 mg/kg body weight doses decreased the arthritic index and footpad swelling. AVE administration diminished pro-inflammatory cytokines in serum and synovial tissues. Reduced chemokines and neutrophil infiltration in synovial tissues after AVE administration dictated its protective effect against RA. Decreased LPO content and SOD activity along with concomitant rise in GSH and CAT activities from liver, spleen and synovial tissues indicated regulation of oxidative stress by AVE. In addition decreased CRP in serum along with suppressed TLR-2 expression in CIA mice after AVE treatment was also observed. Protective effect of AVE in RA is further supported from histopathological studies which showed improvement during bone damage. In conclusion this study demonstrated A. vasica is capable of regulating oxidative stress during CIA and therefore down regulated local and systemic release of pro-inflammatory mediators, which might be linked to mechanism of decreasing synovial TLR-2 expression via downregulating release of its regular endogenous ligands like CRP.

  9. CARVE: Net Ecosystem CO2 Exchange and Regional Carbon Budgets for Alaska, 2012-2014

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides estimates of 3-hourly net ecosystem CO2 exchange (NEE) at 0.5-degree resolution over the state of Alaska for 2012-2014. The NEE estimates are...

  10. A neon-E rich phase in Orgueil - Results of stepwise heating experiments

    Science.gov (United States)

    Eberhardt, P.

    1978-01-01

    A Ne-E rich phase was separated from the Orgeuil carbonaceous chondrite. He and Ne were analyzed in this phase and in an Orgueil residual bulk silicate sample using the stepwise heating technique. Ne-E was found to be released from the Ne-E rich phase at temperatures as low as 500 C; however, gas richest in Ne-E is observed at the highest temperatures (1230 C). The following limits for the isotopic composition of Ne-E were obtained: Ne-20/Ne-22 less than 1.52; Ne-21/Ne-22 less than 0.0244.

  11. Nectandra Rol. ex Rottb. (Lauraceae no Mato Grosso do Sul, Brasil Nectandra Rol. ex Rottb. (Lauraceae in Mato Grosso do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    Flávio Macedo Alves

    2009-03-01

    Full Text Available O trabalho apresenta o estudo taxonômico das espécies do gênero Nectandra no Mato Grosso do Sul, Brasil. Baseados na análise morfológica dos espécimes coletados em diferentes regiões do Estado são confirmados oito espécies de Nectandra: N. amazonum Nees, N. cissiflora Nees, N. cuspidata Nees, N. falcifolia (Nees J.A. Castigl. ex Mart. Crov. & Piccinini, N. gardneri Meisn., N. hihua (Ruiz & Pav. Rohwer, N. megapotamica (Spreng. Mez e N. psammophila Nees. É fornecida uma chave de identificação para as espécies e apresentados descrições morfológicas, dados de distribuição geográfica, habitat, aspectos fenológicos, comentários taxonômicos e ilustrações para cada espécie.This paper presents the taxonomic study of the species of Nectandra from Mato Grosso do Sul. Eight species of Nectandra were identified through the morphological analyses of specimens collected in different regions from the State: N. amazonum Nees, N. cissiflora Nees, N. cuspidata Nees, N. falcifolia (Nees J.A. Castigl. ex Mart. Crov. & Piccinini, N. gardneri Meisn., N. hihua (Ruiz & Pav. Rohwer, N. megapotamica (Spreng. Mez and N. psammophila Nees. Identification key, morphological descriptions, geographic distribution, habitat, fenologic aspect, taxonomic comments, and illustrations are presented.

  12. O gênero Bryopteris (Hepatophyta no Brasil The genus Bryopteris (Hepatophyta in Brazil

    Directory of Open Access Journals (Sweden)

    Eunice de Lemos-Michel

    1998-04-01

    Full Text Available São referidas seis espécies do gênero Bryopteris (Nees Lindenb. no Brasil: B. difusa (Sw. Nees, B. filicina (Sw. Nees, B. flaccida Lindenb. & Hampe, B. fruticulosa T. Taylor, B. liebmanniana Lindenb. & Gott. e B. trinitensis (Lehm. & Lindenb. Lehm. & Lindenb. B. liebmanniana é citada pela primeira vez para o Brasil. Para cada espécie são apresentadas descrição, ilustrações e distribuição geográfica no Brasil.Six species of the genus Bryopteris (Nees Lindenb. are cited to Brazil: B. diffusa (Sw. Nees, B. filicina (Sw. Nees, B. flaccida Lindenb. & Hampe, B. fruticulosa T. Taylor, B. liebmanniana Lindenb. & Gott. and B. trinitensis (Lehm. & Lindenb. Lehm. & Lindenb. B. liebmanniana is cited for the first time in Brazil. Description, illustrations, and geographical distribution are presented for each species.

  13. NACP Site: Terrestrial Biosphere Model and Aggregated Flux Data in Standard Format

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides standardized output variables for gross primary productivity (GPP), net ecosystem exchange (NEE), leaf area index (LAI), ecosystem respiration...

  14. NACP Site: Terrestrial Biosphere Model and Aggregated Flux Data in Standard Format

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides standardized output variables for gross primary productivity (GPP), net ecosystem exchange (NEE), leaf area index (LAI), ecosystem...

  15. Broncodilatory effect of Adatoda shimperina leaf extract on isolated ...

    African Journals Online (AJOL)

    asthma. Typical examples of these compounds are theophilline and ephedrine. Many medicinal plants including A. shimperiana have been documented as remedy for the treatment of asthma in the Ethiopian traditional medicine (4). A. shimperiana (Hochst). Nees Acanthaceae, Synonym Justicia shimperiana. (Nees in DC) ...

  16. Gap filling strategies for defensible annual sums of net ecosystem exchange

    DEFF Research Database (Denmark)

    Falge, E.; Baldocchi, D.; Olson, R.

    2001-01-01

    ecosystem exchange (F-NEE) responses are being made among biome types, phenology patterns, and stress conditions. The comparisons are usually performed on annual sums of F-NEE; however, the average data coverage during a year is only 65%. Therefore, robust and consistent gap filling methods are required. We...

  17. Hepáticas talosas do Parque Nacional da Tijuca, Rio de Janeiro, Brasil

    Directory of Open Access Journals (Sweden)

    Denise P. da Costa

    1987-12-01

    Full Text Available Onze especies de hepáticas talosas são mencionadas para o Parque Nacional da Tijuca, Rio de Janeiro, Brasil: Dumortiera hirsuta (Sw. Nees, Marchantia papillata Raddi, Metzgeria aurantiaca Steph., M. dichotoma (Sw. Nees, M.furcata (L. Dum., Monoclea forsteri Hook. Riccardia cataractarum (Spruce Hell, R. chamedryfolia (With. Grolle, Symphyogyna aspera Steph. ex Evans, S. brasitiensis Nees & Mont, e S. podophylla (Thumb. Mont. & Nees. Metzgeria aurantiaca e Riccardia cataractarum estão sendo mencionadas pela primeira vez para o Rio de Janeiro. Descrição, e distribuição geográfica brasileira para cada espécie são apresentadasEleven species of thallose liverworts are mentioned for the Tijuca National Park, Rio de Janeiro, Brazil: Dumortiera hirsuta (Sw. Nees, Marchantia papillata Raddi, Metzgeria aurantiaca Steph., M. dichotoma (Sw. Nees, M.furcata (L. Dum., Monoclea forsteri Hook. Riccardia cataractarum (Spruce Hell, R. chamedryfolia (With. Grolle, Symphyogyna aspera Steph. ex Evans, S. brasiliensis Nees & Mont., and S. podophylla (Thumb. Mont. & Nees. Metzgeria aurantiaca and Riccardia cataractarum are mentioned for the first time for Rio de Janeiro State. Description, and Brazilian geographical distribution for each taxon are presented

  18. Converging estimates of the forest carbon sink; a comparison of the carbon sink of Scots pine forest in The Netherlands as presented by the eddy covariance and the forest inventory method

    NARCIS (Netherlands)

    Schelhaas, M.J.; Nabuurs, G.J.; Jans, W.W.P.; Moors, E.J.; Sabaté, S.; Daamen, W.P.

    2002-01-01

    The aim of this study was to compare estimates of the net ecosystem exchange (NEE) by two different methods for a small pine forest in the Netherlands. The inventory-based carbon budgeting method estimated the average NEE for 1997-2001 at 202 g C per mr per year, with a confidence interval of

  19. Combining Eddy Covariance Fluxes, High-Precision Trace Gas Measurements, Chemical Transport Modeling, and Inverse Modeling to Estimate Regional CO2 Fluxes in the Southern Great Plains, USA

    NARCIS (Netherlands)

    Hirsch, A. I.; Fischer, M. L.; Biraud, S. C.; Torn, M. S.; Berry, J. A.; Andrews, A. E.; Peters, W.; Zahorowski, W.; Chambers, S. Z.; Tans, P. P.

    2008-01-01

    We use the radon tracer method to estimate monthly average net ecosystem exchange (NEE) of carbon dioxide in the Southern Great Plains of the USA for the year 2007. These estimates are compared with optimized flux estimates of NEE from NOAA CarbonTracker, sampled with a Lagrangian particle

  20. Environmental variation is directly responsible for short- but not long-term variation in forest-atmosphere carbon exchange

    Science.gov (United States)

    Andrew D. Richardson; David Y. Hollinger; John D. Aber; Scott V. Ollinger; Bobby H. Braswell

    2007-01-01

    Tower-based eddy covariance measurements of forest-atmosphere carbon dioxide (CO2) exchange from many sites around the world indicate that there is considerable year-to-year variation in net ecosystem exchange (NEE). Here, we use a statistical modeling approach to partition the interannual variability in NEE (and its component fluxes, ecosystem...

  1. Reconciling estimates of the contemporary North American carbon balance among terrestrial biosphere models, atmospheric inversions, and a new approach for estimating net ecosystem exchange from inventory-based data

    Science.gov (United States)

    Daniel J. Hayes; David P. Turner; Graham Stinson; A. David Mcguire; Yaxing Wei; Tristram O. West; Linda S. Heath; Bernardus Dejong; Brian G. McConkey; Richard A. Birdsey; Werner A. Kurz; Andrew R. Jacobson; Deborah N. Huntzinger; Yude Pan; W. Mac Post; Robert B. Cook

    2012-01-01

    We develop an approach for estimating net ecosystem exchange (NEE) using inventory-based information over North America (NA) for a recent 7-year period (ca. 2000-2006). The approach notably retains information on the spatial distribution of NEE, or the vertical exchange between land and atmosphere of all non-fossil fuel sources and sinks of CO2,...

  2. Seasonal hysteresis of net ecosystem exchange in response to temperature change: Patterns and causes

    NARCIS (Netherlands)

    Niu, S.; Luo, Y.; Montagnani, L.; Janssens, I.A.; Gielen, B.; Rambal, S.; Moors, E.J.; Matteucci, G.

    2011-01-01

    Understanding how net ecosystem exchange (NEE) changes with temperature is central to the debate on climate change-carbon cycle feedbacks, but still remains unclear. Here, we used eddy covariance measurements of NEE from 20 FLUXNET sites (203 site-years of data) in mid- and high-latitude forests to

  3. Hysteresis response of daytime net ecosystem exchange during drought

    Directory of Open Access Journals (Sweden)

    N. Pingintha

    2010-03-01

    Full Text Available Continuous measurements of net ecosystem CO2 exchange (NEE using the eddy-covariance method were made over an agricultural ecosystem in the southeastern US. During optimum environmental conditions, photosynthetically active radiation (PAR was the primary driver controlling daytime NEE, accounting for as much as 67 to 89% of the variation in NEE. However, soil water content became the dominant factor limiting the NEE-PAR response during the peak growth stage. NEE was significantly depressed when high PAR values coincided with very low soil water content. The presence of a counter-clockwise hysteresis of daytime NEE with PAR was observed during periods of water stress. This is a result of the stomatal closure control of photosynthesis at high vapor pressure deficit and enhanced respiration at high temperature. This result is significant since this hysteresis effect limits the range of applicability of the Michaelis-Menten equation and other related expressions in the determination of daytime NEE as a function of PAR. The systematic presence of hysteresis in the response of NEE to PAR suggests that the gap-filling technique based on a non-linear regression approach should take into account the presence of water-limited field conditions. Including this step is therefore likely to improve current evaluation of ecosystem response to increased precipitation variability arising from climatic changes.

  4. Five new additions to the flora of Andaman & Nicobar Islands, India.

    Directory of Open Access Journals (Sweden)

    L. Rasingam

    2015-03-01

    Full Text Available Fioria vitifolia (L. Mattei (Malvaceae, Combretum acuminatum Roxb. (Combretaceae, Marsdenia tinctoria R. Br. (Apocynaceae Phoebe lanceolata (Nees Nees (Lauraceae and Schoenoplectus mucronatus (L. Palla (Cyperaceae collected from Little Andaman Island are reported to be new additions to the flora of the Andaman and Nicobar Islands.   

  5. Biophysical controls on CO2 fluxes of three Northern forests based on long-term eddy covariance data

    DEFF Research Database (Denmark)

    Lagergren, F.; Lindroth, A.; Dellwik, Ebba

    2008-01-01

    Six to nine years of net ecosystem carbon exchange (NEE) data from forests in Hyytiala in Finland, Soro in Denmark and Norunda in Sweden were used to evaluate the interannual variation in the carbon balance. For half-monthly periods, average NEE was calculated for the night-time data. For the day......Six to nine years of net ecosystem carbon exchange (NEE) data from forests in Hyytiala in Finland, Soro in Denmark and Norunda in Sweden were used to evaluate the interannual variation in the carbon balance. For half-monthly periods, average NEE was calculated for the night-time data....... The start date could explain some of the variation in yearly total NEE and gross primary productivity (GPP) in Hyytiala and Soro, but the average maximum photosynthetic capacity in summer explained more of the variation in annual GPP for all sites than start, end or length of the growing season....

  6. Estimation of net ecosystem carbon exchange for the conterminous United States by combining MODIS and AmeriFlux data

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Jingfeng; Zhuang, Qianlai; Baldocchi, Dennis D.; Bolstad, Paul V.; Burns, Sean P.; Chen, Jiquan; Cook, David R.; Curtis, Peter S.; Drake, Bert G.; Foster, David R.; Gu, Lianhong; Hadley, Julian L.; Hollinger, David Y.; Katul, Gabriel G.; Law, Beverly E.; Litvak, Marcy; Ma, Siyan; Martin, Timothy A.; Matamala, Roser; McNulty, Steve; Meyers, Tilden P.; Monson, Russell K.; Munger, J. William; Noormets, Asko; Oechel, Walter C.; Oren, Ram; Richardson, Andrew D.; Schmid, Hans Peter; Scott, Russell L.; Starr, Gregory; Sun, Ge; Suyker, Andrew E.; Torn, Margaret S.; Paw, Kyaw; Verma, Shashi B.; Wharton, Sonia; Wofsy, Steven C.

    2008-10-01

    Eddy covariance flux towers provide continuous measurements of net ecosystem carbon exchange (NEE) for a wide range of climate and biome types. However, these measurements only represent the carbon fluxes at the scale of the tower footprint. To quantify the net exchange of carbon dioxide between the terrestrial biosphere and the atmosphere for regions or continents, flux tower measurements need to be extrapolated to these large areas. Here we used remotely sensed data from the Moderate Resolution Imaging Spectrometer (MODIS) instrument on board the National Aeronautics and Space Administration's (NASA) Terra satellite to scale up AmeriFlux NEE measurements to the continental scale. We first combined MODIS and AmeriFlux data for representative U.S. ecosystems to develop a predictive NEE model using a modified regression tree approach. The predictive model was trained and validated using eddy flux NEE data over the periods 2000-2004 and 2005-2006, respectively. We found that the model predicted NEE well (r = 0.73, p < 0.001). We then applied the model to the continental scale and estimated NEE for each 1 km x 1 km cell across the conterminous U.S. for each 8-day interval in 2005 using spatially explicit MODIS data. The model generally captured the expected spatial and seasonal patterns of NEE as determined from measurements and the literature. Our study demonstrated that our empirical approach is effective for scaling up eddy flux NEE measurements to the continental scale and producing wall-to-wall NEE estimates across multiple biomes. Our estimates may provide an independent dataset from simulations with biogeochemical models and inverse modeling approaches for examining the spatiotemporal patterns of NEE and constraining terrestrial carbon budgets over large areas.

  7. Estimation of Net Ecosystem Carbon Exchange for the Conterminous UnitedStates by Combining MODIS and AmeriFlux Data

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Jingfeng; Zhuang, Qianlai; Baldocchi, Dennis D.; Law, Beverly E.; Richardson, Andrew D.; Chen, Jiquan; Oren, Ram; Starr, Gregory; Noormets, Asko; Ma, Siyan; Verma, Shashi B.; Wharton, Sonia; Wofsy, Steven C.; Bolstad, Paul V.; Burns, Sean P.; Cook, David R.; Curtis, Peter S.; Drake, Bert G.; Falk, Matthias; Fischer, Marc L.; Foster, David R.; Gu, Lianhong; Hadley, Julian L.; Hollinger, David Y.; Katul, Gabriel G.; Litvak, Marcy; Martin, Timothy A.; Matamala, Roser; McNulty, Steve; Meyers, Tilden P.; Monson, Russell K.; Munger, J. William; Oechel, Walter C.; U, Kyaw Tha Paw; Schmid, Hans Peter; Scott, Russell L.; Sun, Ge; Suyker, Andrew E.; Torn, Margaret S.

    2009-03-06

    Eddy covariance flux towers provide continuous measurements of net ecosystem carbon exchange (NEE) for a wide range of climate and biome types. However, these measurements only represent the carbon fluxes at the scale of the tower footprint. To quantify the net exchange of carbon dioxide between the terrestrial biosphere and the atmosphere for regions or continents, flux tower measurements need to be extrapolated to these large areas. Here we used remotely-sensed data from the Moderate Resolution Imaging Spectrometer (MODIS) instrument on board NASA's Terra satellite to scale up AmeriFlux NEE measurements to the continental scale. We first combined MODIS and AmeriFlux data for representative U.S. ecosystems to develop a predictive NEE model using a regression tree approach. The predictive model was trained and validated using NEE data over the periods 2000-2004 and 2005-2006, respectively. We found that the model predicted NEE reasonably well at the site level. We then applied the model to the continental scale and estimated NEE for each 1 km x 1 km cell across the conterminous U.S. for each 8-day period in 2005 using spatially-explicit MODIS data. The model generally captured the expected spatial and seasonal patterns of NEE. Our study demonstrated that our empirical approach is effective for scaling up eddy flux NEE measurements to the continental scale and producing wall-to-wall NEE estimates across multiple biomes. Our estimates may provide an independent dataset from simulations with biogeochemical models and inverse modeling approaches for examining the spatiotemporal patterns of NEE and constraining terrestrial carbon budgets for large areas.

  8. Voltammetry of redox analytes at trace concentrations with nanoelectrode ensembles.

    Science.gov (United States)

    Moretto, Ligia Maria; Pepe, Niki; Ugo, Paolo

    2004-04-19

    Gold nanoelectrodes ensembles (NEEs) have been prepared by electroless plating of Au nanoelectrode elements within the pores of a microporous polycarbonate template membrane. Cyclic voltammograms recorded in (ferrocenylmethyl) trimethylammonium hexafluorophosphate (FA(+) PF(6)(-)) solutions showed that these NEEs operate in the "total-overlap" response regime, giving well resolved peak shaped voltammograms. Experimental results show that the faradaic/background currents ratios at the NEE are independent on the total geometric area of the ensemble, so that NEE can be enlarged or miniaturized at pleasure without influencing the very favorable signal/noise ratio. Differential pulse voltammetry (DPV) at the NEE is optimized for direct determinations at trace levels. DPV at NEE allowed the determination (with no preconcentration) of trace amounts of FA(+), with a detection limit of 0.02muM. The use of NEE and DPV in cytochrome c (cyt c) solutions showed the possibility to observe the direct electrochemistry of submicromolar concentration of the protein, even without the need of adding any promoter or mediator.

  9. The effects of biomass burning aerosols and clouds on the CO{sub 2} flux in Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Paulo H.F. E-mail: pauloh@if.usp.br; Artaxo, Paulo; Pires, Carlos; Lucca, Silvia De [Laboratorio de Fisica Atmosferica, Inst. de Fisica, Univ. de Sao Paulo, Rua do Matao, Travessa R, 187, Sao Paulo, SP, CEP 05508-900 (Brazil); Procopio, Aline [Dept. de Engenharia Bioquimica, Univ. Federal do Rio de Janeiro, Av. Brig. Trompowski, Rio de Janeiro, R.J., CEP: 21949-900 (Brazil); Holben, Brent; Schafer, Joel [NASA Goddard Space Flight Center, Greenbelt (United States); Cardoso, Luiz F. [UNIR Fundacao Univ. Federal de Rondonia, Campus de Ji-Parana, Ji-Parana (Brazil); Wofsy, Steven C. [Harvard Univ., Dept. of Earth and Planetary Science, 29 Oxford St., Cambridge, MA 02138 (United States); Rocha, Humberto R. [Dept. de Ciencias Atmosfericas - IAG - Univ. de Sao Paulo, Rua do Matao, 1226 - CEP 05508-900, Sao Paulo (Brazil)

    2007-07-15

    Aerosol particles associated with biomass burning emissions affect the surface radiative budget and net ecosystem exchange (NEE) over large areas in Amazonia during the dry season. We analysed CO{sub 2} fluxes as a function of aerosol loading for two forest sites in Amazonia as part of the LBA experiment. Aerosol optical thickness (AOT) measurements were made with AERONET sun photometers, and CO{sub 2} flux measurements were determined by eddy-correlation. The enhancement of the NEE varied with different aerosol loading, as well as cloud cover, solar elevation angles and other parameters. The AOT value with the strongest effect on the NEE in the FLONA-TapajOs site was 1.7, with an enhancement of the NEE of 11% compared with clear-sky conditions. In the RBJ site, the strongest effect was for AOT of 1.6 with an enhancement of 18% in the NEE. For values of AOT lager than 2.7, strong reduction on the NEE was observed due to the reduction in the total solar radiation. The enhancement in the NEE is attributed to the increase of diffuse versus direct solar radiation. Due to the fact that aerosols from biomass burning are present in most tropical areas, its effects on the global carbon budget could also be significant.

  10. Basic chromosome numbers and polyploid levels in some South African and Australian grasses (Poaceae

    Directory of Open Access Journals (Sweden)

    J. J. Spies

    1991-12-01

    Full Text Available Chromosome numbers of 46 specimens of grasses, involving 24 taxa from South Africa and Australia, have been determined during the present study. For the first time chromosome numbers are given for Eragrostis sarmentosa (Thunb. Trin. (n = 20. Panicum aequinerve Nees (n = 18,  Digitaria argyrograpta (Nees Stapf (n = 9 and D. maitlandii Stapf & C.E. Hubb. (n = 9. Additional polyploid levels are described for Diplachne fusca (L. Beauv. ex Roem. & Schult. (n = 10 and Digitaria diagonalis (Nees Stapf var.  diagonalis (n = 9.B-chromosomes were observed in several different specimens. The presence of B-chromosomes often results in abnormal chromosomal behaviour during meiosis.

  11. Desenvolvimento pós-seminal de espécies de Poaceae (Poales) Post-seminal development of Poaceae species (Poales)

    OpenAIRE

    Adriana Tiemi Nakamura; Vera Lucia Scatena

    2009-01-01

    O presente estudo objetivou verificar a existência de um padrão do desenvolvimento pós-seminal em Poaceae. Para tanto, foram estudadas as seguintes espécies: Olyra humilis Nees (Bambusoideae); Axonopus aureus P. Beauv. e Paspalum polyphyllum Nees ex Trin. (Panicoideae); Chloris elata Nees e Eragrostis solida Desv. (Chloridoideae). Procurou-se também comparar as estruturas da plântula de Poaceae com as demais monocotiledôneas. As espécies estudadas são plantas perenes, rizomatosas, cespitosas ...

  12. Ovule, fruit and seed development in species of Poaceae (Poales)

    OpenAIRE

    Nakamura, Adriana Tiemi; Longhi-Wagner, Hilda Maria; Scatena, Vera Lucia

    2009-01-01

    O desenvolvimento de óvulo, fruto e semente de Olyra humilis Nees e Sucrea monophylla Soderstr. (Bambusoideae), Axonopus aureus P. Beauv. e Paspalum polyphyllum Nees ex Trin. (Panicoideae), Chloris elata Desv. e Eragrostis solida Nees (Chloridoideae) foram estudados visando à caracterização embriológica dessas subfamílias de Poaceae. As espécies apresentam óvulo bitegumentado, micrópila formada pelo tegumento interno, megagametófito tipo Polygonum, endosperma nuclear e amiláceo, embrião later...

  13. Leaf anatomy of the South African Danthonieae (Poaceae. XVI. The genus Urochlaena

    Directory of Open Access Journals (Sweden)

    R. P. Ellis

    1988-12-01

    Full Text Available The leaf blade anatomy of Urochlaena pusilla Nees is described and illustrated. The transectional anatomy is non- Kranz with diffuse but uniformly distributed chlorenchyma. The abaxial epidermis has dome-shaped stomata, dumbbell­shaped silica bodies, elongated finger-like microhairs, and cushion-based macrohairs may or may not be present. This type of arundinoid anatomy closely resembles that o f  Tribolium Desv.,  Chaetobromus Nees,  Schismus Beauv., and certain species of Pentaschistis Stapf.  Urochlaena pusilla is very similar to  Tribolium utriculosum (Nees Renv. in leaf anatomy and these two species appear to be closely related.

  14. Basic chromosome numbers and polyploid levels in some South African and Australian grasses (Poaceae

    Directory of Open Access Journals (Sweden)

    J. J. Spies

    1991-10-01

    Full Text Available Chromosome numbers of 46 specimens of grasses, involving 24 taxa from South Africa and Australia, have been determined during the present study. For the first time chromosome numbers are given for Eragrostis sarmentosa (Thunb. Trin. (n = 20. Panicum aequinerve Nees (n = 18,  Digitaria argyrograpta (Nees Stapf (n = 9 and D. maitlandii Stapf & C.E. Hubb. (n = 9. Additional polyploid levels are described for Diplachne fusca (L. Beauv. ex Roem. & Schult. (n = 10 and Digitaria diagonalis (Nees Stapf var.  diagonalis (n = 9. B-chromosomes were observed in several different specimens. The presence of B-chromosomes often results in abnormal chromosomal behaviour during meiosis.

  15. Nonlinear waves in waveguides with stratification

    CERN Document Server

    Leble, Sergei B

    1991-01-01

    S.B. Leble's book deals with nonlinear waves and their propagation in metallic and dielectric waveguides and media with stratification. The underlying nonlinear evolution equations (NEEs) are derived giving also their solutions for specific situations. The reader will find new elements to the traditional approach. Various dispersion and relaxation laws for different guides are considered as well as the explicit form of projection operators, NEEs, quasi-solitons and of Darboux transforms. Special points relate to: 1. the development of a universal asymptotic method of deriving NEEs for guide propagation; 2. applications to the cases of stratified liquids, gases, solids and plasmas with various nonlinearities and dispersion laws; 3. connections between the basic problem and soliton- like solutions of the corresponding NEEs; 4. discussion of details of simple solutions in higher- order nonsingular perturbation theory.

  16. NACP MCI: CO2 Flux from Inversion Modeling, Upper Midwest Region, USA, 2007

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set provides estimates of Net Ecosystem Exchange (NEE) flux for the U.S. Upper Midwest at 0.5-degree resolution for the year 2007. Estimates were...

  17. NACP MCI: CO2 Flux from Inversion Modeling, Upper Midwest Region, USA, 2007

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides estimates of Net Ecosystem Exchange (NEE) flux for the U.S. Upper Midwest at 0.5-degree resolution for the year 2007. Estimates were produced...

  18. Biotic, abiotic, and management controls on the net ecosystem CO2 exchange of European mountain grassland ecosystems

    DEFF Research Database (Denmark)

    Wohlfahrt, Georg; Friborg, Thomas; Johansson et.al., Paul Torbjörn

    2008-01-01

    The net ecosystem carbon dioxide (CO2) exchange (NEE) of nine European mountain grassland ecosystems was measured during 2002-2004 using the eddy covariance method. Overall, the availability of photosynthetically active radiation (PPFD) was the single most important abiotic influence factor for NEE....... Its role changed markedly during the course of the season, PPFD being a better predictor for NEE during periods favorable for CO2 uptake, which was spring and autumn for the sites characterized by summer droughts (southern sites) and (peak) summer for the Alpine and northern study sites. This general...... pattern was interrupted by grassland management practices, that is, mowing and grazing, when the variability in NEE explained by PPFD decreased in concert with the amount of aboveground biomass (BMag). Temperature was the abiotic influence factor that explained most of the variability in ecosystem...

  19. Nitrous Oxide Ethane Ethylene Engine Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nitrous Oxide Ethane-Ethylene (NEE) engine is a proposed technology designed to provide spacecraft with non-toxic non-cryogenic high-performance propulsion. With...

  20. Controls on mangrove forest‐atmosphere carbon dioxide exchanges in western Everglades National Park

    National Research Council Canada - National Science Library

    Barr, Jordan G; Engel, Vic; Fuentes, José D; Zieman, Joseph C; O'Halloran, Thomas L; Smith, Thomas J; Anderson, Gordon H

    2010-01-01

    ... ) between a mangrove forest and the atmosphere in the coastal Florida Everglades. An eddy covariance system deployed above the canopy was used to determine NEE during January 2004 through August 2005...

  1. Validation Of DEM Data Dvied From World View 3 Stero Imagery For Low Elevation Majuro Atoll, Marchall Islands

    Science.gov (United States)

    The availability of surface elevation data for the Marshall Islands has been identified as a "massive" data gap for conducting vulnerability assessments and the subsequent development of climate change adaption strategies. Specifically, digital elevation model (DEM) data are nee...

  2. La atencion a los padres con hijos con necesidades educativas especiales

    National Research Council Canada - National Science Library

    Pernas Pico, Claudia Maria

    2011-01-01

    Los padres que tienen hijos con necesidades educativas especiales (NEE) necesitan al igual que sus hijos de la intervencion del maestro de Audicion y Lenguaje con el objetivo primordial de mejorar la comunicacion y el lenguaje de los ninos...

  3. Haapsalu gümnaasiumi filmistuudio avas uksed / Kaie Mäemurd

    Index Scriptorium Estoniae

    Mäemurd, Kaie

    2006-01-01

    Eesti ainus koolifilmistuudio avas 6. okt. uksed. Stuudio asub kooli õpilaskodu majas. Stuudios õpitakse foto- ja filmitegemist, tehakse kohalikke uudiseid televisioonile jpm Õpetavad Sven Tehu, Margus Nee ja Madis Leppik

  4. Improving Toponym Disambiguation by Iteratively Enhancing Certainty of Extraction

    NARCIS (Netherlands)

    Habib, Mena Badieh; van Keulen, Maurice

    2012-01-01

    Named entity extraction (NEE) and disambiguation (NED) have received much attention in recent years. Typical fields addressing these topics are information retrieval, natural language processing, and semantic web. This paper addresses two problems with toponym extraction and disambiguation (as a

  5. APPLICATIONS OF A CONCEPTUAL MODEL (THE BIOLOGICAL CONDITION GRADIENT) TO DEFINE AQUATIC REFERENCE CONDITIONS

    Science.gov (United States)

    The United States Clean Water Act currently offers no definitions to interpret the Act's objective to "restore and maintain physical, chemical and biological integrity of the Nation's waters". Operative definitions, independent of differences in assessment methodologies, are nee...

  6. NACP North American 8-km Net Ecosystem Exchange and Component Fluxes, 2004

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides modeled carbon flux estimates at 8-km spatial resolution over North America for the year 2004 of (1) net ecosystem exchange (NEE) of carbon...

  7. Real-Time Multi-Directional Equipment Site

    Data.gov (United States)

    Federal Laboratory Consortium — As part of the George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Program, Lehigh University has established the Real-Time Multi-Directional...

  8. 77 FR 41205 - Sunshine Act Meetings; National Science Board

    Science.gov (United States)

    2012-07-12

    ... Earthquake Engineering Research Infrastructure (NEES) Beyond 2014 ] Director's Remarks NSB Discussion Item... University of Illinois for Blue Waters M&O CPP Program Portfolio Planning--Follow-up from Cognitive...

  9. Aromatic compounds from three Brazilian Lauraceae species

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Andrea Nastri de Luca; Batista Junior, Joao Marcos; Lopez, Silvia Noeli; Furlan, Maysa; Cavalheiro, Alberto Jose; Silva, Dulce Helena Siqueira; Bolzani, Vanderlan da Silva [UNESP, Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Quimica Organica; Nunomura, Sergio Massayoshi [Instituto Nacional de Pesquisa da Amazonia (INPA), Manaus, AM (Brazil). Dept. de Produtos Naturais; Yoshida, Massayoshi [Centro de Biotecnologia da Amazonia, Manaus, AM (Brazil)

    2010-07-01

    Phytochemical investigations on three Brazilian Lauraceae species from the Cerrado region of Sao Paulo State, Ocotea corymbosa (Meins) Mez., O. elegans Mez. and Persea pyrifolia Nees and Mart. ex Nees resulted in the isolation of flavonoids, an ester of the 4-O-E-caffeoylquinic acid, an aromatic sesquiterpene besides furofuran lignans. This is the first chemical study on the leaves of Ocotea elegans and O. corymbosa as well as the first report of non-volatile compounds from Persea pyrifolia. (author)

  10. Authentication of true cinnamon (Cinnamon verum) utilising direct analysis in real time (DART)-QToF-MS.

    Science.gov (United States)

    Avula, Bharathi; Smillie, Troy J; Wang, Yan-Hong; Zweigenbaum, Jerry; Khan, Ikhlas A

    2015-01-01

    The use of cinnamon as a spice and flavouring agent is widespread throughout the world. Many different species of plants are commonly referred to as 'cinnamon'. 'True cinnamon' refers to the dried inner bark of Cinnamomum verum J. S. Presl (syn. C. zeylanicum) (Lauraceae). Other 'cinnamon' species, C. cassia (Nees & T. Nees) J. Presl (syn. C. aromaticum Nees) (Chinese cassia), C. loureiroi Nees (Saigon cassia), and C. burmannii (Nees & T. Nees) Blume (Indonesian cassia), commonly known as cassia, are also marketed as cinnamon. Since there is a prevalence of these various types of 'cinnamons' on the market, there is a need to develop a rapid technique that can readily differentiate between true cinnamon (C. verum) and other commonly marketed species. In the present study, coumarin and other marker compounds indicative of 'cinnamon' were analysed using DART-QToF-MS in various samples of cinnamon. This method involved the use of [M + H](+) ions in positive mode in addition to principal component analysis (PCA) using Mass Profiler Professional software to visualise several samples for quality and to discriminate 'true cinnamon' from other Cinnamomum species using the accurate mass capabilities of QToF-MS.

  11. Detection of DNA Hybridization by Methylene Blue Electrochemistry at Activated Nanoelectrode Ensembles.

    Science.gov (United States)

    Silvestrini, Morena; Fruk, Ljiljana; Moretto, Ligia Maria; Ugo, Paolo

    2015-05-01

    Nanoelectrode ensembles (NEEs) obtained by electroless gold deposition in track-etched poly-carbonate (PC) membranes are functionalized and applied for DNA hybridization detection, using methylene blue (MB) as electroactive probe. To this aim, an amine terminated (ss)DNA probe is immobilized on the PC surface of the NEE by reaction via carbodiimide and N-hydroxysulfosuccinimide. In order to increase the number of carboxylic groups present on PC and suitable for the functionalization, the surface of NEEs is oxidized with potassium permanganate. The presence of carboxylic functionalities is verified by spectrochemical titration with thionin acetate (THA) and the effect of the activation treatment on the electrode performances is evaluated by cyclic voltammetry (CV). After activation and functionalization with the probes, the NEE-based sensor is hybridized with complementary target sequences. The effect of the functionalization of the NEEs both with the (ss)DNA probe alone and after hybridization with the target, is studied by measuring the changes in the MB reduction signal by square wave voltammetry (SWV), after incubation in a suitable MB solution, rinsing and transfer to the measurement cell. It was observed that this peak signal decreases significantly after hybridization of the probe with the complementary target. Experimental evidences suggest that the interaction between MB and the guanines of (ss)DNA and (ds)DNA is at the basis of the development of the here observed analytical signal. The proposed approach allows the easy preparation and testing of NEE-based sensors for the electrochemical DNA hybridization detection.

  12. The native and naturalised species of Peltocalathos and Ranunculus (Ranunculaceae: Ranunculeae in southern Africa

    Directory of Open Access Journals (Sweden)

    J. C. Manning

    2013-01-01

    Full Text Available The five native and naturalised species of Ranunculus L. and Peltocalathos Tamaru (Ranunculaceae: Ranunculeae from southern Africa are reviewed, with full descriptions and nomenclature, taxonomic history, ecological notes, and distribution data. All species are illustrated. Peltocalathos, a monotypic genus based on R. baurii MacOwan, has been overlooked in the regional literature until now. The new name R. dregei J.C.Manning & Goldblatt is proposed as a replacement name for the later homonym R. meyeri Harv., non Lowe. We conclude that the poorly known R. capensis Thunb. represents juvenile forms of the widespread and variable R. multifidus Forssk. and we synonymise the name, along with the three trivial epithets R. pinnatus var. hermannii DC., R. pubescens var. glabrescens Burtt Davy and R. pubescens var. harveyanus Burtt Davy, which have been overlooked in the recent literature. Based on number (mostly < 40 achenes per head and size (mostly 1.2–1.8 mm long of achenes, we conclude that the southern African material of the aquatic species recently re-identified as R. rionii Lagger is more appropriately treated as R. trichophyllus Chaix.

  13. Analysis of the influence of climatic and physiological parameters on the net ecosystem carbon exchange of an apple orchard

    Science.gov (United States)

    Zanotelli, Damiano; Montagnani, Leonardo; Scandellari, Francesca; Tagliavini, Massimo

    2013-04-01

    Net ecosystem carbon exchange (NEE) of an apple orchard located in South Tyrol (Caldaro, Bolzano, Italy) was monitored continuously since March 2009 via eddy covariance technique. Contemporary measurements of the main environmental parameters (temperature, photosynthetic active photon flux density, soil water content, vapor pressure deficit) were taken at the same field site. Leaf Area Index was also determined biometrically starting from spring 2010. Objectives of this work were (i) to assess the influence of these environmental and physiological parameters on NEE, (ii) to set up a model capable to fill large gap occurring in the dataset and (iii) predict inter-annual variability of fluxes based on the measurements of the selected explanatory variables. Daily cumulated values of the response variable (NEE, g C d-1) and mean daily value of the five explanatory variables considered (air T, ° C; SWC, m3m-3; PPFD, μmol m-2s-1; VPD, hPa, LAI m2m-2) were used in this analysis. The complex interactions between the explanatory variables and NEE were analyzed with the tree model approach which draws a picture of the complexity of data structure and highlights the explanatory variable that explain the greater amount of deviance of the response variable. NEE variability was mostly explained by LAI and PPFD. The most positive values of NEE occurred below the LAI threshold of 1.16 m2m-2 while above that LAI threshold and with an average daily PPFD above 13.2 μmol m-2s-1, the orchard resulted always a sink of carbon (negative daily NEE). On half of the available data (only alternate months of the considered period were considered), a stepwise multiple regression approach was used to model NEE using the variables indicated above. Simplification by deletion of the non-significant terms was carried out until all parameters where highly significant (p analysis, the model was further improved by transforming the linear predictor. Akaikés Information Criterion (AIC) was used to

  14. Evaluation and uncertainty analysis of regional-scale CLM4.5 net carbon flux estimates

    Science.gov (United States)

    Post, Hanna; Hendricks Franssen, Harrie-Jan; Han, Xujun; Baatz, Roland; Montzka, Carsten; Schmidt, Marius; Vereecken, Harry

    2018-01-01

    Modeling net ecosystem exchange (NEE) at the regional scale with land surface models (LSMs) is relevant for the estimation of regional carbon balances, but studies on it are very limited. Furthermore, it is essential to better understand and quantify the uncertainty of LSMs in order to improve them. An important key variable in this respect is the prognostic leaf area index (LAI), which is very sensitive to forcing data and strongly affects the modeled NEE. We applied the Community Land Model (CLM4.5-BGC) to the Rur catchment in western Germany and compared estimated and default ecological key parameters for modeling carbon fluxes and LAI. The parameter estimates were previously estimated with the Markov chain Monte Carlo (MCMC) approach DREAM(zs) for four of the most widespread plant functional types in the catchment. It was found that the catchment-scale annual NEE was strongly positive with default parameter values but negative (and closer to observations) with the estimated values. Thus, the estimation of CLM parameters with local NEE observations can be highly relevant when determining regional carbon balances. To obtain a more comprehensive picture of model uncertainty, CLM ensembles were set up with perturbed meteorological input and uncertain initial states in addition to uncertain parameters. C3 grass and C3 crops were particularly sensitive to the perturbed meteorological input, which resulted in a strong increase in the standard deviation of the annual NEE sum (σ ∑ NEE) for the different ensemble members from ˜ 2 to 3 g C m-2 yr-1 (with uncertain parameters) to ˜ 45 g C m-2 yr-1 (C3 grass) and ˜ 75 g C m-2 yr-1 (C3 crops) with perturbed forcings. This increase in uncertainty is related to the impact of the meteorological forcings on leaf onset and senescence, and enhanced/reduced drought stress related to perturbation of precipitation. The NEE uncertainty for the forest plant functional type (PFT) was considerably lower (σ ∑ NEE ˜ 4.0-13.5 g C

  15. Growing season net ecosystem CO2 exchange of two desert ecosystems with alkaline soils in Kazakhstan

    Science.gov (United States)

    Li, Longhui; Chen, Xi; van der Tol, Christiaan; Luo, Geping; Su, Zhongbo

    2014-01-01

    Central Asia is covered by vast desert ecosystems, and the majority of these ecosystems have alkaline soils. Their contribution to global net ecosystem CO2 exchange (NEE) is of significance simply because of their immense spatial extent. Some of the latest research reported considerable abiotic CO2 absorption by alkaline soil, but the rate of CO2 absorption has been questioned by peer communities. To investigate the issue of carbon cycle in Central Asian desert ecosystems with alkaline soils, we have measured the NEE using eddy covariance (EC) method at two alkaline sites during growing season in Kazakhstan. The diurnal course of mean monthly NEE followed a clear sinusoidal pattern during growing season at both sites. Both sites showed significant net carbon uptake during daytime on sunny days with high photosynthetically active radiation (PAR) but net carbon loss at nighttime and on cloudy and rainy days. NEE has strong dependency on PAR and the response of NEE to precipitation resulted in an initial and significant carbon release to the atmosphere, similar to other ecosystems. These findings indicate that biotic processes dominated the carbon processes, and the contribution of abiotic carbon process to net ecosystem CO2 exchange may be trivial in alkaline soil desert ecosystems over Central Asia. PMID:24455157

  16. Differential responses of net ecosystem exchange of carbon dioxide to light and temperature between spring and neap tides in subtropical mangrove forests.

    Science.gov (United States)

    Li, Qing; Lu, Weizhi; Chen, Hui; Luo, Yiqi; Lin, Guanghui

    2014-01-01

    The eddy flux data with field records of tidal water inundation depths of the year 2010 from two mangroves forests in southern China were analyzed to investigate the tidal effect on mangrove carbon cycle. We compared the net ecosystem exchange (NEE) and its responses to light and temperature, respectively, between spring tide and neap tide inundation periods. For the most time of the year 2010, higher daytime NEE values were found during spring tides than during neap tides at both study sites. Regression analysis of daytime NEE to photosynthetically active radiation (PAR) using the Landsberg model showed increased sensitivity of NEE to PAR with higher maximum photosynthetic rate during spring tides than neap tides. In contrast, the light compensation points acquired from the regression function of the Landsberg model were smaller during spring tides than neap tides in most months. The dependence of nighttime NEE on soil temperature was lower under spring tide than under neap tides. All these results above indicated that ecosystem carbon uptake rates of mangrove forests were strengthened, while ecosystem respirations were inhibited during spring tides in comparison with those during neap tides, which needs to be considered in modeling mangrove ecosystem carbon cycle under future sea level rise scenarios.

  17. Combining MODIS data and tower based measurements to estimate net ecosystem carbon exchange for the Republic of Ireland

    Science.gov (United States)

    Murphy, K.; Clement, F.; Kiely, G.

    2012-04-01

    A number of previous studies have employed Fluxnet data in developing models to upscale localised eddy covariance (EC) footprints in order to determine net ecosystem carbon exchange (NEE) over regional or national scales. This study combined measured EC flux data (from three EC stations in Ireland over the period 2002-2007) with data from the Moderate Resolution Imaging Spectrometer (MODIS) onboard the Terra (EOS-AM) Satellite, and land cover maps (Corine Land Cover for 2006) to develop predictive NEE models using an adapted regression tree method allowing upscaling to wider areas with MODIS products. Separate models were developed for the four main ecosystem types found in the Republic of Ireland: grassland, peatland, forestry and cropland. The NEE models showed promising correlations with the EC measurements of NEE for training and predictive data sets. Excluding urban and water areas, the results indicate that Ireland's terrestrial ecosystems are a sink for CO2 of -1.3Mg C-CO2 ha-1 y-1 giving a national estimate of -9.3 Tg C-CO2 y-1. This uptake compares to the national inventory estimate for emissions from agriculture of 5.03 Tg C-CO2 eq y-1. The models also captured well the spatiotemporal variations over the Republic of Ireland relative to the measured NEE in different ecosystem types over different seasons. The method shows potential in accounting for carbon fluxes over large areas.

  18. Differential Responses of Net Ecosystem Exchange of Carbon Dioxide to Light and Temperature between Spring and Neap Tides in Subtropical Mangrove Forests

    Directory of Open Access Journals (Sweden)

    Qing Li

    2014-01-01

    Full Text Available The eddy flux data with field records of tidal water inundation depths of the year 2010 from two mangroves forests in southern China were analyzed to investigate the tidal effect on mangrove carbon cycle. We compared the net ecosystem exchange (NEE and its responses to light and temperature, respectively, between spring tide and neap tide inundation periods. For the most time of the year 2010, higher daytime NEE values were found during spring tides than during neap tides at both study sites. Regression analysis of daytime NEE to photosynthetically active radiation (PAR using the Landsberg model showed increased sensitivity of NEE to PAR with higher maximum photosynthetic rate during spring tides than neap tides. In contrast, the light compensation points acquired from the regression function of the Landsberg model were smaller during spring tides than neap tides in most months. The dependence of nighttime NEE on soil temperature was lower under spring tide than under neap tides. All these results above indicated that ecosystem carbon uptake rates of mangrove forests were strengthened, while ecosystem respirations were inhibited during spring tides in comparison with those during neap tides, which needs to be considered in modeling mangrove ecosystem carbon cycle under future sea level rise scenarios.

  19. Response to Special Educational Needs and Teaching Efforts in Elementary School

    Directory of Open Access Journals (Sweden)

    Mayela Dabdub-Moreira

    2015-07-01

    Full Text Available De acuerdo con la Ley de Igualdad de Oportunidades para las Personas con Discapacidad en Costa Rica (Ley N.º 7600, los maestros deben recibir y atender individuos con necesidades educativas especiales (NEE dentro de sus clases regulares y saber cómo aplicar las diferentes adecuaciones curriculares. Por lo tanto, conocer la cantidad y el tipo de NEE que atienden los educadores y las áreas en las que estos expresan requerir facultarse, permite mejorar considerablemente la calidad y la eficiencia de las actualizaciones profesionales que se brindan a los docentes y la atención asertiva de las NEE. Para recolectar esta información, se realizó una entrevista a quince maestros de primero a sexto grado en una escuela privada en Moravia, Costa Rica. Los resultados visibilizan que las principales necesidades educativas que ellos intentan solventar son los trastornos de atención y los problemas emocionales. Las principales limitaciones que enfrentan los educadores para atender las NEE son falta de tiempo y poco apoyo de las familias. Las áreas en las que indicaron requerir capacitación son relacionadas con la aplicación eficaz de adecuaciones curriculares y las metodologías específicas para las NEE. La investigación presenta utilidad tanto para la docencia como para la Psicopedagogía.

  20. Estimating carbon dioxide fluxes from temperate mountain grasslands using broad-band vegetation indices

    Directory of Open Access Journals (Sweden)

    G. Wohlfahrt

    2010-02-01

    Full Text Available The broad-band normalised difference vegetation index (NDVI and the simple ratio (SR were calculated from measurements of reflectance of photosynthetically active and short-wave radiation at two temperate mountain grasslands in Austria and related to the net ecosystem CO2 exchange (NEE measured concurrently by means of the eddy covariance method. There was no significant statistical difference between the relationships of midday mean NEE with narrow- and broad-band NDVI and SR, measured during and calculated for that same time window, respectively. The skill of broad-band NDVI and SR in predicting CO2 fluxes was higher for metrics dominated by gross photosynthesis and lowest for ecosystem respiration, with NEE in between. A method based on a simple light response model whose parameters were parameterised based on broad-band NDVI allowed to improve predictions of daily NEE and is suggested to hold promise for filling gaps in the NEE time series. Relationships of CO2 flux metrics with broad-band NDVI and SR however generally differed between the two studied grassland sites indicting an influence of additional factors not yet accounted for.

  1. The genus Schoenoxiphium (Cyperaceae. A preliminary account

    Directory of Open Access Journals (Sweden)

    I. Kukkonen

    1983-12-01

    Full Text Available The genus Schoenoxiphium of the tribe Cariceae of Cyperaceae is conservatively accepted as being restricted to the African continent and Madagascar. The special features of the inflorescence structure are described. The following species are provisionally recognized: S. basutorum Turrill, S. distinctum Kukkonen, S. ecklonii Nees, S.  filiforme Kükenthal, S. gracile Chermezon, S. lanceum (Thunberg Kukenthal, S. lehmannii (Nees Steudel, S.  madagascariense Chermezon, S. perdensum Kukkonen, S. rufum Nees, S. schweickerdtii Merxmiiller & Podlech, and  S. sparteum (Wahlenberg Kukenthal. A key to the species is provided and their distribution is roughly outlined. The morphological variation within the species suggests separation of taxa below specific level, or perhaps even at species level, but this will require more detailed information about the ecology, distribution and the cytology.

  2. Dynamics in carbon exchange fluxes for a grazed semi-arid savanna ecosystem in West Africa

    DEFF Research Database (Denmark)

    Tagesson, Torbern; Fensholt, Rasmus; Cropley, Ford

    2015-01-01

    The main aim of this paper is to study land-atmosphere exchange of carbon dioxide (CO2) for semi-arid savanna ecosystems of the Sahel region and its response to climatic and environmental change. A subsidiary aim is to study and quantify the seasonal dynamics in light use efficiency (ε) being a key...... variable in scaling carbon fluxes from ground observations using earth observation data. The net ecosystem exchange of carbon dioxide (NEE) 2010-2013 was measured using the eddy covariance technique at a grazed semi-arid savanna site in Senegal, West Africa. Night-time NEE was not related to temperature......, confirming that care should be taken before applying temperature response curves for hot dry semi-arid regions when partitioning NEE into gross primary productivity (GPP) and ecosystem respiration (Reco). Partitioning was instead done using light response curves. The values of ε ranged between 0.02g carbon...

  3. An annotated catalogue of the Iranian Euphorinae, Gnamptodontinae, Helconinae, Hormiinae and Rhysipolinae (Hymenoptera: Braconidae).

    Science.gov (United States)

    Gadallah, Neveen S; Ghahari, Hassan; Achterberg, Kees Van

    2016-01-28

    The Iranian species diversity of five braconid subfamilies, Euphorinae (54 species in 16 genera and 8 tribes), Gnamptodontinae (4 species in 1 genus and 1 tribe), Helconinae (9 species in 5 genera and 2 tribes), Hormiinae (8 species in 4 genera and 2 tribe) and Rhysipolinae (3 species in 2 genera) are summarized in this catalogue. A faunistic list is given comprising both local and global distribution of each species under study as well as host records. In the present study ten new records are added to the Iranian fauna: Centistes (Ancylocentrus) ater (Nees), Centistes cuspidatus (Haliday), Meteorus affinis (Wesmael), Meteorus rufus (DeGeer), Microctonus brevicollis (Haliday), Microctonus falciger Ruthe, Peristenus nitidus (Curtis) (Euphorinae), Aspicolpus carinator (Nees), Diospilus capito (Nees) and Diospilus productus Marshall (Helconinae s.l.). Euphorus pseudomitis Hedwig, 1957 is transferred to the subfamily Hormiinae and Hormisca pseudomitis (Hedwig, 1957) is a new combination.

  4. The genus Schoenoxiphium (Cyperaceae. A preliminary account

    Directory of Open Access Journals (Sweden)

    I. Kukkonen

    1983-11-01

    Full Text Available The genus Schoenoxiphium of the tribe Cariceae of Cyperaceae is conservatively accepted as being restricted to the African continent and Madagascar. The special features of the inflorescence structure are described. The following species are provisionally recognized: S. basutorum Turrill, S. distinctum Kukkonen, S. ecklonii Nees, S.  filiforme Kükenthal, S. gracile Chermezon, S. lanceum (Thunberg Kukenthal, S. lehmannii (Nees Steudel, S.  madagascariense Chermezon, S. perdensum Kukkonen, S. rufum Nees, S. schweickerdtii Merxmiiller & Podlech, and  S. sparteum (Wahlenberg Kukenthal. A key to the species is provided and their distribution is roughly outlined. The morphological variation within the species suggests separation of taxa below specific level, or perhaps even at species level, but this will require more detailed information about the ecology, distribution and the cytology.

  5. Net ecosystem exchange of CO2 and carbon balance for eight temperate organic soils under agricultural management

    DEFF Research Database (Denmark)

    Elsgaard, Lars; Görres, C.-M.; Hoffmann, Carl Christian

    2012-01-01

    This study presents the first annual estimates of net ecosystem exchange (NEE) of CO2 and net ecosystem carbon balances (NECB) of contrasting Danish agricultural peatlands. Studies were done at eight sites representing permanent grasslands (PG) and rotational (RT) arable soils cropped to barley......) sites, NEE (mean ± standard error, SE) was 5.1 ± 0.9 and 8.6 ± 2.0 Mg C ha−1 yr−1, respectively, but with the overall lowest value observed for potato cropping (3.5 Mg C ha−1 yr−1). This was partly attributed to a short-duration vegetation period and drying of the soil especially in potato ridges. NECB...... and temperate climate zones. It was stressed that evaluation of emission factors should explicitly differentiate between data representing net C balance from a soil perspective and CO2-C balance from an atmospheric perspective. Modelling of inter-annual variability in NEE for three selected sites during a 21...

  6. Colonization of a Deglaciated Moraine: Contrasting Patterns of Carbon Uptake and Release from C3 and CAM Plants.

    Directory of Open Access Journals (Sweden)

    Elisa Varolo

    Full Text Available Current glacier retreat makes vast mountain ranges available for vegetation establishment and growth. As a result, carbon (C is accumulated in the soil, in a negative feedback to climate change. Little is known about the effective C budget of these new ecosystems and how the presence of different vegetation communities influences CO2 fluxes.On the Matsch glacier forefield (Alps, Italy we measured over two growing seasons the Net Ecosystem Exchange (NEE of a typical grassland, dominated by the C3 Festuca halleri All., and a community dominated by the CAM rosettes Sempervivum montanum L. Using transparent and opaque chambers, with air temperature as the driver, we partitioned NEE to calculate Ecosystem Respiration (Reco and Gross Ecosystem Exchange (GEE. In addition, soil and vegetation samples were collected from the same sites to estimate the Net Ecosystem Carbon Balance (NECB.The two communities showed contrasting GEE but similar Reco patterns, and as a result they were significantly different in NEE during the period measured. The grassland acted as a C sink, with a total cumulated value of -46.4±35.5 g C m-2 NEE, while the plots dominated by the CAM rosettes acted as a source, with 31.9±22.4 g C m-2. In spite of the different NEE, soil analysis did not reveal significant differences in carbon accumulation of the two plant communities (1770±130 for F. halleri and 2080±230 g C m-2 for S. montanum, suggesting that processes often neglected, like lateral flows and winter respiration, can have a similar relevance as NEE in the determination of the Net Ecosystem Carbon Balance.

  7. Response of carbon dioxide exchange to grazing intensity over typical steppes in a semi-arid area of Inner Mongolia

    Science.gov (United States)

    Wang, Lei; Liu, Huizhi; Bernhofer, Christian

    2017-05-01

    The eddy covariance technique was used to measure the CO2 flux over four differently grazed Leymus chinensis steppe ecosystems (ungrazed since 1979 (UG79), winter grazed (WG), continuously grazed (CG), and heavily grazed (HG) sites) during four growing seasons (May to September) from 2005 to 2008, to investigate the response of the net ecosystem exchange (NEE) over grassland ecosystems to meteorological factors and grazing intensity. At UG79, the optimal air temperature for the half-hourly NEE occurred between 17 and 20 °C, which was relatively low for semi-arid grasslands. The saturated NEE (NEEsat) and temperature sensitivity coefficient ( Q 10) of ecosystem respiration (RE) exhibited clear seasonal and interannual variations, which increased with canopy development and the soil water content (SWC, at 5 cm). The total NEE values for the growing seasons from 2005 to 2008 were -32.0, -41.5, -66.1, and -89.8 g C m-2, respectively. Both the amounts and distribution of precipitation during the growing season affected the NEE. The effects of grazing on the CO2 flux increased with the grazing intensity. During the peak growth stage, heavy grazing and winter grazing decreased NEEsat and gross primary production (45 % for HG and 34 % for WG) due to leaf area removal. Both RE and Q 10 were clearly reduced by heavy grazing. Heavy grazing changed the ecosystem from a CO2 sink into a CO2 source, and winter grazing reduced the total CO2 uptake by 79 %. In the early growing season, there was no difference in the NEE between CG and UG79. In addition to the grazing intensity, the effects of grazing on the CO2 flux also varied with the vegetation growth stages and SWC.

  8. Complementarity of flux- and biometric-based data to constrain parameters in a terrestrial carbon model

    Directory of Open Access Journals (Sweden)

    Zhenggang Du

    2015-03-01

    Full Text Available To improve models for accurate projections, data assimilation, an emerging statistical approach to combine models with data, have recently been developed to probe initial conditions, parameters, data content, response functions and model uncertainties. Quantifying how many information contents are contained in different data streams is essential to predict future states of ecosystems and the climate. This study uses a data assimilation approach to examine the information contents contained in flux- and biometric-based data to constrain parameters in a terrestrial carbon (C model, which includes canopy photosynthesis and vegetation–soil C transfer submodels. Three assimilation experiments were constructed with either net ecosystem exchange (NEE data only or biometric data only [including foliage and woody biomass, litterfall, soil organic C (SOC and soil respiration], or both NEE and biometric data to constrain model parameters by a probabilistic inversion application. The results showed that NEE data mainly constrained parameters associated with gross primary production (GPP and ecosystem respiration (RE but were almost invalid for C transfer coefficients, while biometric data were more effective in constraining C transfer coefficients than other parameters. NEE and biometric data constrained about 26% (6 and 30% (7 of a total of 23 parameters, respectively, but their combined application constrained about 61% (14 of all parameters. The complementarity of NEE and biometric data was obvious in constraining most of parameters. The poor constraint by only NEE or biometric data was probably attributable to either the lack of long-term C dynamic data or errors from measurements. Overall, our results suggest that flux- and biometric-based data, containing different processes in ecosystem C dynamics, have different capacities to constrain parameters related to photosynthesis and C transfer coefficients, respectively. Multiple data sources could also

  9. Impact of cloudiness on net ecosystem exchange of carbon dioxide in different types of forest ecosystems in China

    Science.gov (United States)

    Zhang, M.; Yu, G.-R.; Zhang, L.-M.; Sun, X.-M.; Wen, X.-F.; Han, S.-J.; Yan, J.-H.

    2010-02-01

    Clouds can significantly affect carbon exchange process between forest ecosystems and the atmosphere by influencing the quantity and quality of solar radiation received by ecosystem's surface and other environmental factors. In this study, we analyzed the effects of cloudiness on net ecosystem exchange of carbon dioxide (NEE) in a temperate broad-leaved Korean pine mixed forest at Changbaishan (CBS) and a subtropical evergreen broad-leaved forest at Dinghushan (DHS), based on the flux data obtained during June-August from 2003 to 2006. The results showed that the response of NEE of forest ecosystems to photosynthetically active radiation (PAR) differed under clear skies and cloudy skies. Compared with clear skies, the light-saturated maximum photosynthetic rate (Pec,max) at CBS under cloudy skies during mid-growing season (from June to August) increased by 34%, 25%, 4% and 11% in 2003, 2004, 2005 and 2006, respectively. In contrast, Pec,max of the forest ecosystem at DHS was higher under clear skies than under cloudy skies from 2004 to 2006. When the clearness index (kt) ranged between 0.4 and 0.6, the NEE reached its maximum at both CBS and DHS. However, the NEE decreased more dramatically at CBS than at DHS when kt exceeded 0.6. The results indicate that cloudy sky conditions are beneficial to net carbon uptake in the temperate forest ecosystem and the subtropical forest ecosystem. Under clear skies, vapor pressure deficit (VPD) and air temperature increased due to strong light. These environmental conditions led to greater decrease in gross ecosystem photosynthesis (GEP) and greater increase in ecosystem respiration (Re) at CBS than at DHS. As a result, clear sky conditions caused more reduction of NEE in the temperate forest ecosystem than in the subtropical forest ecosystem. The response of NEE of different forest ecosystems to the changes in cloudiness is an important factor that should be included in evaluating regional carbon budgets under climate change

  10. Colonization of a Deglaciated Moraine: Contrasting Patterns of Carbon Uptake and Release from C3 and CAM Plants.

    Science.gov (United States)

    Varolo, Elisa; Zanotelli, Damiano; Montagnani, Leonardo; Tagliavini, Massimo; Zerbe, Stefan

    2016-01-01

    Current glacier retreat makes vast mountain ranges available for vegetation establishment and growth. As a result, carbon (C) is accumulated in the soil, in a negative feedback to climate change. Little is known about the effective C budget of these new ecosystems and how the presence of different vegetation communities influences CO2 fluxes. On the Matsch glacier forefield (Alps, Italy) we measured over two growing seasons the Net Ecosystem Exchange (NEE) of a typical grassland, dominated by the C3 Festuca halleri All., and a community dominated by the CAM rosettes Sempervivum montanum L. Using transparent and opaque chambers, with air temperature as the driver, we partitioned NEE to calculate Ecosystem Respiration (Reco) and Gross Ecosystem Exchange (GEE). In addition, soil and vegetation samples were collected from the same sites to estimate the Net Ecosystem Carbon Balance (NECB). The two communities showed contrasting GEE but similar Reco patterns, and as a result they were significantly different in NEE during the period measured. The grassland acted as a C sink, with a total cumulated value of -46.4±35.5 g C m-2 NEE, while the plots dominated by the CAM rosettes acted as a source, with 31.9±22.4 g C m-2. In spite of the different NEE, soil analysis did not reveal significant differences in carbon accumulation of the two plant communities (1770±130 for F. halleri and 2080±230 g C m-2 for S. montanum), suggesting that processes often neglected, like lateral flows and winter respiration, can have a similar relevance as NEE in the determination of the Net Ecosystem Carbon Balance.

  11. Regional inversion of CO2 ecosystem fluxes from atmospheric measurements. Reliability of the uncertainty estimates

    Energy Technology Data Exchange (ETDEWEB)

    Broquet, G.; Chevallier, F.; Breon, F.M.; Yver, C.; Ciais, P.; Ramonet, M.; Schmidt, M. [Laboratoire des Sciences du Climat et de l' Environnement, CEA-CNRS-UVSQ, UMR8212, IPSL, Gif-sur-Yvette (France); Alemanno, M. [Servizio Meteorologico dell' Aeronautica Militare Italiana, Centro Aeronautica Militare di Montagna, Monte Cimone/Sestola (Italy); Apadula, F. [Research on Energy Systems, RSE, Environment and Sustainable Development Department, Milano (Italy); Hammer, S. [Universitaet Heidelberg, Institut fuer Umweltphysik, Heidelberg (Germany); Haszpra, L. [Hungarian Meteorological Service, Budapest (Hungary); Meinhardt, F. [Federal Environmental Agency, Kirchzarten (Germany); Necki, J. [AGH University of Science and Technology, Krakow (Poland); Piacentino, S. [ENEA, Laboratory for Earth Observations and Analyses, Palermo (Italy); Thompson, R.L. [Max Planck Institute for Biogeochemistry, Jena (Germany); Vermeulen, A.T. [Energy research Centre of the Netherlands ECN, EEE-EA, Petten (Netherlands)

    2013-07-01

    The Bayesian framework of CO2 flux inversions permits estimates of the retrieved flux uncertainties. Here, the reliability of these theoretical estimates is studied through a comparison against the misfits between the inverted fluxes and independent measurements of the CO2 Net Ecosystem Exchange (NEE) made by the eddy covariance technique at local (few hectares) scale. Regional inversions at 0.5{sup 0} resolution are applied for the western European domain where {approx}50 eddy covariance sites are operated. These inversions are conducted for the period 2002-2007. They use a mesoscale atmospheric transport model, a prior estimate of the NEE from a terrestrial ecosystem model and rely on the variational assimilation of in situ continuous measurements of CO2 atmospheric mole fractions. Averaged over monthly periods and over the whole domain, the misfits are in good agreement with the theoretical uncertainties for prior and inverted NEE, and pass the chi-square test for the variance at the 30% and 5% significance levels respectively, despite the scale mismatch and the independence between the prior (respectively inverted) NEE and the flux measurements. The theoretical uncertainty reduction for the monthly NEE at the measurement sites is 53% while the inversion decreases the standard deviation of the misfits by 38 %. These results build confidence in the NEE estimates at the European/monthly scales and in their theoretical uncertainty from the regional inverse modelling system. However, the uncertainties at the monthly (respectively annual) scale remain larger than the amplitude of the inter-annual variability of monthly (respectively annual) fluxes, so that this study does not engender confidence in the inter-annual variations. The uncertainties at the monthly scale are significantly smaller than the seasonal variations. The seasonal cycle of the inverted fluxes is thus reliable. In particular, the CO2 sink period over the European continent likely ends later than

  12. Toward Verifying Fossil Fuel CO2 Emissions with the CMAQ Model: Motivation, Model Description and Initial Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhen; Bambha, Ray P.; Pinto, Joseph P.; Zeng, Tao; Boylan, Jim; Huang, Maoyi; Lei, Huimin; Zhao, Chun; Liu, Shishi; Mao, Jiafu; Schwalm, Christopher R.; Shi, Xiaoying; Wei, Yaxing; Michelsen, Hope A.

    2014-03-14

    Motivated by the urgent need for emission verification of CO2 and other greenhouse gases, we have developed regional CO2 simulation with CMAQ over the contiguous U.S. Model sensitivity experiments have been performed using three different sets of inputs for net ecosystem exchange (NEE) and two fossil fuel emission inventories, to understand the roles of fossil fuel emissions, atmosphere-biosphere exchange and transport in regulating the spatial and diurnal variability of CO2 near the surface, and to characterize the well-known ‘signal-to-noise’ problem, i.e. the interference from the biosphere on the interpretation of atmospheric CO2 observations. It is found that differences in the meteorological conditions for different urban areas strongly contribute to the contrast in concentrations. The uncertainty of NEE, as measured by the difference among the three different NEE inputs, has notable impact on regional distribution of CO2 simulated by CMAQ. Larger NEE uncertainty and impact are found over eastern U.S. urban areas than along the western coast. A comparison with tower CO2 measurements at Boulder Atmospheric Observatory (BAO) shows that the CMAQ model using hourly varied and high-resolution CO2 emission from the Vulcan inventory and CarbonTracker optimized NEE reasonably reproduce the observed diurnal profile, whereas switching to different NEE inputs significantly degrades the model performance. Spatial distribution of CO2 is found to correlate with NOx, SO2 and CO, due to their similarity in emission sources and transport processes. These initial results from CMAQ demonstrate the power of a state-of-the art CTM in helping interpret CO2 observations and verify fossil fuel emissions. The ability to simulate CO2 in CMAQ will also facilitate investigations of the utility of traditionally regulated pollutants and other species as tracers to CO2 source attribution.

  13. Programa de atención para adolescentes y jóvenes con necesidades educativas específicas de la UANL; México

    OpenAIRE

    Martínez, R.T.; Durán, P.M.; R Ortíz; Rojas, A.

    2017-01-01

    Objetivo General: identificar estudiantes del nivel medio superior de la Universidad Autónoma de Nuevo León (UANL), con Necesidades Educativas Específicas (NEE), cuyo diagnóstico permitirá establecer un programa de intervención que facilite la obtención de resultados académicos y personales satisfactorios. Material y método: con el fin de identificar estudiantes de primer ingreso al nivel medio superior de la UANL con NEE, se aplicó una encuesta a sus padres. Los estudiantes identificados fue...

  14. Robots & Necessidades Educativas Especiais: O desenho de uma oficina de formação para a aplicação da robótica educativa em contexto inclusivo

    OpenAIRE

    Marcão, Cristina Isabel Conchinha, 1978-

    2017-01-01

    A Robótica Educativa (RE) tem assumido um papel crescente nas nossas escolas. Estudos nacionais e internacionais têm destacado o seu potencial pedagógico com alunos com Necessidades Educativas Especiais (NEE), mas faltava sensibilizar e capacitar os professores para a utilização desta ferramenta em contexto inclusivo. Pretendeu-se, neste estudo desenhar, testar e aperfeiçoar um modelo de oficina de formação sobre a RE aplicada às NEE, numa abordagem metodológica mista, de carácter explo...

  15. Diurnal and Seasonal Variations in the Net Ecosystem CO2 Exchange of a Pasture in the Three-River Source Region of the Qinghai-Tibetan Plateau.

    Directory of Open Access Journals (Sweden)

    Bin Wang

    Full Text Available Carbon dioxide (CO2 exchange between the atmosphere and grassland ecosystems is very important for the global carbon balance. To assess the CO2 flux and its relationship to environmental factors, the eddy covariance method was used to evaluate the diurnal cycle and seasonal pattern of the net ecosystem CO2 exchange (NEE of a cultivated pasture in the Three-River Source Region (TRSR on the Qinghai-Tibetan Plateau from January 1 to December 31, 2008. The diurnal variations in the NEE and ecosystem respiration (Re during the growing season exhibited single-peak patterns, the maximum and minimum CO2 uptake observed during the noon hours and night; and the maximum and minimum Re took place in the afternoon and early morning, respectively. The minimum hourly NEE rate and the maximum hourly Re rate were -7.89 and 5.03 μmol CO2 m-2 s-1, respectively. The NEE and Re showed clear seasonal variations, with lower values in winter and higher values in the peak growth period. The highest daily values for C uptake and Re were observed on August 12 (-2.91 g C m-2 d-1 and July 28 (5.04 g C m-2 day-1, respectively. The annual total NEE and Re were -140.01 and 403.57 g C m-2 year-1, respectively. The apparent quantum yield (α was -0.0275 μmol μmol-1 for the entire growing period, and the α values for the pasture's light response curve varied with the leaf area index (LAI, air temperature (Ta, soil water content (SWC and vapor pressure deficit (VPD. Piecewise regression results indicated that the optimum Ta and VPD for the daytime NEE were 14.1°C and 0.65 kPa, respectively. The daytime NEE decreased with increasing SWC, and the temperature sensitivity of respiration (Q10 was 3.0 during the growing season, which was controlled by the SWC conditions. Path analysis suggested that the soil temperature at a depth of 5 cm (Tsoil was the most important environmental factor affecting daily variations in NEE during the growing season, and the photosynthetic photon

  16. Diurnal and Seasonal Variations in the Net Ecosystem CO2 Exchange of a Pasture in the Three-River Source Region of the Qinghai?Tibetan Plateau

    OpenAIRE

    Wang, Bin; Jin, Haiyan; Li, Qi; Chen, Dongdong; Zhao,Liang; Tang, Yanhong; Kato, Tomomichi; Gu, Song

    2017-01-01

    Carbon dioxide (CO2) exchange between the atmosphere and grassland ecosystems is very important for the global carbon balance. To assess the CO2 flux and its relationship to environmental factors, the eddy covariance method was used to evaluate the diurnal cycle and seasonal pattern of the net ecosystem CO2 exchange (NEE) of a cultivated pasture in the Three-River Source Region (TRSR) on the Qinghai?Tibetan Plateau from January 1 to December 31, 2008. The diurnal variations in the NEE and eco...

  17. Clinical characteristics of eosinophilic asthma exacerbations

    DEFF Research Database (Denmark)

    Bjerregaard, Asger; Laing, Ingrid A; Backer, Vibeke

    2017-01-01

    at baseline, of whom 43% had sputum eosinophils ≥3% (EE). Patients with EE had a significantly lower forced expiratory volume in 1 s (FEV1 ) % predicted (70.8%, P = 0.03) than patients with NEE (83.6%). Furthermore, EE patients were more likely to require supplemental oxygen during admission (63% vs 14%, P...... = 0.002). The prevalence of respiratory viruses was the same in EE and NEE patients (44% vs 52%, P = 0.60), as was bacterial infection (6% vs 14%, P = 0.44). Fractional expiratory nitric oxide (FeNO) correlated with sputum %-eosinophils (ρ = 0.57, P

  18. New combinations and synonyms in Neotropical Lejeuneaceae (Marchantiophyta, with description of Lejeunea tamasii, a new species from Barro Colorado Island, Panama

    Directory of Open Access Journals (Sweden)

    Reiner-Drehwald M. Elena

    2013-12-01

    Full Text Available The new species Lejeunea tamasii M. E. Reiner, N. Salazar Allen & C. Chung C. from Barro Colorado Island, Panama, named in honor of Professor Tamás Pócs, is described and illustrated. Lejeunea tonduzana (Steph. M. E. Reiner, comb. nov. (basionym: Hygrolejeunea tonduzana Steph., L. recurva M. E. Reiner, nom. nov. (basionym: Hygrolejeunea recurva Steph. ex Bonner, nom. inval., H. herzogii Steph. 1916, nom.illeg., and new synonyms in Lejeunea cerina (Lehm. & Lindenb. Gottsche, Lindenb. & Nees (= Hygrolejeunea aspera Steph., = H. similis Steph. and Lejeunea flava (Sw. Nees (= Hygrolejeunea bahiensis Steph. are proposed. Descriptions and illustrations for Lejeunea tonduzana and L. recurva are also provided.

  19. Taxonomy and leaf anatomy of the genus Ehrharta (Poaceae in southern Africa: the Dura group

    Directory of Open Access Journals (Sweden)

    G. E. Gibbs Russel

    1988-12-01

    Full Text Available The Dura species group in the genus Ehrharta Thunb. is differentiated morphologically by the perennial habit and the very large, awned, subglabrous spikelets and anatomically by the occurrence of tanniniferous cells and wax platelets obscuring the stomatal pores. The Dura group consists of two species, E. dura Nees ex Trin. and E. microlaena Nees ex Trin., which occur only in Mountain Fynbos. The group shows no clear morphological or anatomical relationship with other species groups in the genus in southern Africa.

  20. La Influencia de Prácticas de Lectoescritura en los Alumnos con Necesidades Educativas Especiales

    OpenAIRE

    Blanco Moreno, Beatriz A.

    2016-01-01

    El presente estudio aborda el tema de aprendizaje de lectoescritura. Se indaga sobre la pregunta de investigación relativa a ¿Cuál es la influencia de la aplicación de prácticas de lectoescritura en los alumnos con NEE entre 7 y 12 años relacionadas con el desarrollo de esta habilidad. Se tomaron en cuenta tres objetivos de investigación. El primero describió las actividades prácticas de lectoescritura para que los alumnos con NEE accedan a la misma, el segundo dio a conocer las característic...

  1. Updated checklist of Iranian Opiinae (Hymenoptera: Braconidae).

    Science.gov (United States)

    Gadallah, Neveen S; Ghahari, Hassan; Peris-Felipo, Francisco Javier; Fischer, Maximilian

    2016-01-12

    An updated checklist of Opiinae from Iran is provided including 101 species from 11 genera (Atormus van Achterberg, 1997, Biosteres Foerster, 1862, Eurytenes Forster, 1862, Fopius Wharton, 1987, Indiopius Fischer, 1966, Opius Wesmael, 1835, Phaedrotoma Forster, 1862, Pokomandya Fischer, 1959, Psyttalia Walker, 1860, Utetes Forster, 1862 and Xynobius Forster, 1862) belonging to two tribes (Biosterini and Opiini). Moreover, seven species Biosteres (Chilotrichia) punctiscuta (Thomson, 1895), Biosteres (Biosteres) remigii Fischer, 1971, Eurytenes (Eurytenes) abnormis (Wesmael, 1835), Opius (Hypocynodus) ponticus Fischer, 1958, Opius pygmaeator (Nees, 1811), Opius (Nosopoea) speciosus Fischer, 1959 and Phaedrotoma nitidulator (Nees, 1834) are recorded for the first time from Iran.

  2. New species and taxonomic changes within Pentaschistis (Danthonioideae, Poaceae from Western Cape, South Africa

    Directory of Open Access Journals (Sweden)

    C. A. Galley

    2006-08-01

    Full Text Available Three new species of Pentaschistis (Nees Stapf are described from the Cape Floristic Region. P. trifida. P clavata and P. horrida. The former has been collected from inland ranges of the Cape Fold Belt, from the Cederberg to the Groot Swartberg. the last two each from single sites in the Koue Bokkeveld:  P. clavata on the wetter western border, and P. horrida on the Baviaansberg. Pentaschistis juncifolia Stapf is re-instated, a species from the coastal plains (Hardeveld between Bredasdorp and Riversdale, which had been included in P. eriostoma (Nees Stapf.

  3. Detecting management and fertilization effects on the carbon balance of winter oilseed rape with manual closed chamber measurements: Can we outrange gap-filling uncertainty and spatiotemporal variability?

    Science.gov (United States)

    Huth, Vytas; Moffat, Antje Maria; Calmet, Anna; Andres, Monique; Laufer, Judit; Pehle, Natalia; Rach, Bernd; Gundlach, Laura; Augustin, Jürgen

    2017-04-01

    Winter oilseed rape is the dominant biofuel crop in the young moraine landscape in North-Eastern Germany. However, studies on the effect of rapeseed cropping on net ecosystem exchange of CO2 (NEE) and the soil carbon (SC) balance are scarce. SC balance estimates are usually derived from long-term soil sampling field trials where rapeseed is part of different crop rotations. The estimated annual differences linked to rapeseed cropping are rather small (varying between losses of 40 g C m-2 and gains of up to 100 g C m-2). Testing management effects on the NEE and SC balance of cropping systems is best done by comparing plots with different treatments at the same site under the same climate. The soil sampling approach is in the need of field trials that run over decades, which has the disadvantage that management strategies of practical farming may have already changed when the results are derived. Continuous eddy covariance measurements of NEE would require large fields in flat terrain for each of the treatments, which is especially complicated in the heterogeneous landscapes of glacigenic origin of North-Eastern Germany. The common approach of using the chamber technique to derive NEE, however, is subject to the local soil and plant stand heterogeneities due to its tiny footprint. This technique might also disturb the ecosystem, the measurements are usually discontinuous requiring elaborate gap-filling techniques, and it has mostly been used on organic soils where large respiratory C losses occur. Therefore, our aim was to answer, if a combined approach of the eddy covariance and the chamber technique can detect the relatively small NEE and SC differences of rapeseed cropping on mineral soils within a shorter period of time than conventional soil sampling field trials can. We tested the new experimental design taking the advantages of both techniques into account: The eddy covariance tower measuring the NEE dynamics during the year; the chamber measurements to

  4. Browse Title Index

    African Journals Online (AJOL)

    Issue, Title. Vol 10, No 15 (2011), Assessment of genetic diversity among accessions of two traditional leafy vegetables (Acmella uliginosa (L.) and Justicia tenella (Nees) T.) consumed in Benin using amplified fragment length polymorphism (AFLP) markers, Abstract PDF. K Adéoti, A Rival, A Dansi, BS Ahohuendo, ...

  5. Author Details

    African Journals Online (AJOL)

    Abdela, J. Vol 30, No 2 (2014) - Articles In Vivo Antimalarial Activity of Solvent Fractions of the Leaves of Justicia schimperiana Hochst. Ex Nees Against Plasmodium berghei in Mice Abstract. ISSN: 1029-5933. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More ...

  6. In Vivo Antimalarial Activity of Solvent Fractions of the Leaves of ...

    African Journals Online (AJOL)

    Increasing resistance of Plasmodium falciparum to almost all the available antimalarial drugs urges a search for newer antimalarial drugs. Justicia schimperiana Hochst. Ex Nees is traditionally used for the treatment of malaria and a study conducted previously on the crude leaf extract confirmed that the plant is endowed ...

  7. Side Effects of Drugs. Annual 17: 1993 ABC of Sexually Transmitted ...

    African Journals Online (AJOL)

    kleur geken nie. Hy word oorleef deur drie kinders, Gisela, Ingrid en Detlef en vyf kleinkinders uit sy eerste huwelik met Erika wat hem etlike jare reeds ontval het. Ons betuig ens meegevoel met sy gesin en veral met sy eggenote Margaret (nee Mitchel) wat horn in sy laaste jare en siekte so liefdevol versorg het. Books.

  8. Effects of standardized methanol extract of Andrographis paniculata ...

    African Journals Online (AJOL)

    Extracts of Andrographis paniculata Nees is used in traditional medicine for the treatment several diseases including inflammation, asthma and common cold. The aim of this study was to investigate the possible effects of a clinical dose of the methanol extract of A. paniculata (AP) on tracheal cyclooxygenase and ...

  9. Imidacloprid of niet? (interview met Sjef van der Steen)

    NARCIS (Netherlands)

    Kleis, R.; Steen, van der J.J.M.

    2014-01-01

    Is bijensterfte het werk van neonicotinoïden? Ja, zeggen en denken velen. Volgens hen zijn de neo’s rechtstreeks verantwoordelijk voor de hoge sterfte onder bijen. Nee, toont Wagenings onderzoek aan. Intussen lijkt het met de sterfte voorzichtig de goede kant op te gaan.

  10. Relationship between field resistance to Phytophthora ramorum and constitutive phenolic chemistry of coast live oak

    Science.gov (United States)

    A.M. Nagle; B.A. McPherson; D.L. Wood; M. Garbelotto; A.O. Conrad; S. Opiyo; P. Bonello

    2012-01-01

    Sudden oak death, caused by Phytophthora ramorum, has resulted in high levels of coast live oak (Quercus agrifolia Nee (CLO) mortality. However, some CLO survive in areas with high disease pressure and may thus be resistant. We tested the hypothesis that such field resistant trees contain constitutively higher levels of...

  11. The Matador Technique: A technique to improve prostatic ...

    African Journals Online (AJOL)

    A. Pai

    electromagnetic fusion sensors [6] and robotic-assisted needle placement [7–10]. However, further clinical trials are required before these techniques can be widely used. The benefit of the Matador Technique is a marked reduction of prostatic rotation by simultaneous insertion of the first two nee- dles on either side of the ...

  12. On the identity of Curvularia subulata

    NARCIS (Netherlands)

    Tan, C.S.; Hoog, de G.S.

    1987-01-01

    Occasionally fungal strains have been received by the ‘Centraalbureau voor Schimmelcultures’ under the name Curvularia subulata (Nees) Boedijn. This name also turns up in the literature (Corbetta, 1965; Jalal & al., 1984). A culture, carrying this name and deposited recently at the CBS, was

  13. Compensatory water effects link yearly global land CO2 sink changes to temperature

    Science.gov (United States)

    Jung, Martin; Reichstein, Markus; Schwalm, Christopher R.; Huntingford, Chris; Sitch, Stephen; Ahlström, Anders; Arneth, Almut; Camps-Valls, Gustau; Ciais, Philippe; Friedlingstein, Pierre; Gans, Fabian; Ichii, Kazuhito; Jain, Atul K.; Kato, Etsushi; Papale, Dario; Poulter, Ben; Raduly, Botond; Rödenbeck, Christian; Tramontana, Gianluca; Viovy, Nicolas; Wang, Ying-Ping; Weber, Ulrich; Zaehle, Sönke; Zeng, Ning

    2017-01-01

    Large interannual variations in the measured growth rate of atmospheric carbon dioxide (CO2) originate primarily from fluctuations in carbon uptake by land ecosystems. It remains uncertain, however, to what extent temperature and water availability control the carbon balance of land ecosystems across spatial and temporal scales. Here we use empirical models based on eddy covariance data and process-based models to investigate the effect of changes in temperature and water availability on gross primary productivity (GPP), terrestrial ecosystem respiration (TER) and net ecosystem exchange (NEE) at local and global scales. We find that water availability is the dominant driver of the local interannual variability in GPP and TER. To a lesser extent this is true also for NEE at the local scale, but when integrated globally, temporal NEE variability is mostly driven by temperature fluctuations. We suggest that this apparent paradox can be explained by two compensatory water effects. Temporal water-driven GPP and TER variations compensate locally, dampening water-driven NEE variability. Spatial water availability anomalies also compensate, leaving a dominant temperature signal in the year-to-year fluctuations of the land carbon sink. These findings help to reconcile seemingly contradictory reports regarding the importance of temperature and water in controlling the interannual variability of the terrestrial carbon balance. Our study indicates that spatial climate covariation drives the global carbon cycle response.

  14. A trade-off between diapause duration and fitness in female parasitoids.

    NARCIS (Netherlands)

    Ellers, J.; van Alphen, J.J.M.

    2002-01-01

    1. Diapause allows insects to cope with adverse weather conditions but also poses substantial fitness costs, e,g. through reduced survival of the diapausing stage or sublethal effects in the following season. 2. The energetic costs of diapause in females of the parasitoid Asobara tabida Nees

  15. R-ES-ONANCE--I-Ju-ne--2-0-06------------~~~~----------------------------3

    Indian Academy of Sciences (India)

    Smith, Cyril Stanley (1903-1992), metallurgist and historian of technology, was born on 4 October 1903 in Birmingham, the third of the four children of Joseph Seymour. Smith, a commercial traveller for Camp coffee, and his wife, Frances, nee Norton. (1871-1949). He was brought up in a Methodist household. He was ...

  16. Climate control of terrestrial carbon exchange across biomes and continents

    DEFF Research Database (Denmark)

    Yi, Chuixiang; Ricciuto, Daniel; Li, Runze

    2010-01-01

    climate and terrestrial CO2 exchange with the atmosphere across biomes and continents are lacking. Here we present data describing the relationships between net ecosystem exchange of carbon (NEE) and climate factors as measured using the eddy covariance method at 125 unique sites in various ecosystems...

  17. Évaluation de la diversité floristique en herbacées des savanes de ...

    African Journals Online (AJOL)

    Thus, 37 species, 33 kinds and 10 families were identified in the savannah of Hyparrhenia diplandra (Hack.) Stapf and 27 species, 22 kinds and 8 families in the savannah of Loudetia simplex (Nees) CE Hubbard. Overall, the richest families in species were Poaceae, Fabaceae and the Cyperaceae. The Shannon diversity ...

  18. Linda S. Gottfredson

    Science.gov (United States)

    Wainer, Howard; Robinson, Daniel H.

    2009-01-01

    This article presents an interview with Linda Gottfredson (nee Howarth), who obtained her BA (psychology, Phi Beta Kappa) from UC Berkeley in 1969, served in the Peace Corps in the Malaysian Health Service from 1969 to 1972, and received her PhD (sociology) from Johns Hopkins University (JHU) in 1976. She was Research Scientist at JHU's Center for…

  19. The West Palaearctic species of the subfamily Paxylommatinae (Hymenoptera: Ichneumonidae), with special reference to the genus Hybrizon Fallén

    NARCIS (Netherlands)

    Achterberg, van C.

    1999-01-01

    The West Palaearctic species of the subfamily Paxylommatinae are reviewed and the species of the genus Hybrizon Fallén, 1813, from the Palaearctic region are keyed. Hybrizon juncoi (Ceballos, 1957) is recognized as a valid species, a neotype is designated for Hybrizon latebricola Nees, 1834, and a

  20. Named Entity Extraction and Linking Challenge: University of Twente at #Microposts2014

    NARCIS (Netherlands)

    Habib, Mena Badieh; van Keulen, Maurice; Zhu, Zhemin; Rowe, Matthew; Stankovic, Milan; Dadzie, Aba-Sah

    Twitter is a potentially rich source of continuously and instantly updated information. Shortness and informality of tweets are challenges for Natural Language Processing (NLP) tasks. In this paper, we present a hybrid approach for Named Entity Extraction (NEE)and Linking (NEL) for tweets. Although

  1. Helbredsrelateret livskvalitet ved kraeft

    DEFF Research Database (Denmark)

    Grønvold, Mogens

    2008-01-01

    The article reviews methods, experiences, and results of quality of life research in cancer, and presents recommendations. The research has comprised descriptive studies, end-points in clinical trials, prognostic studies, and clinical applications of quality of life questionnaires. There is a nee...

  2. Effects of climate variability and functional changes on the interannual variation of the carbon balance in a temperate deciduous forest

    DEFF Research Database (Denmark)

    Wu, Jian; van der Linden, Leon; Lasslop, G.

    2012-01-01

    The net ecosystem exchange of CO2 (NEE) between the atmosphere and a temperate beech forest showed a significant interannual variation (IAV) and a decadal trend of increasing carbon uptake (Pilegaard et al., 2011). The objectives of this study were to evaluate to what extent and at which temporal...

  3. Carbon isotope ratios document that the elytra of western corn rootworm reflects adult versus larval feeding and later instar larvae prefer Bt corn to alternate hosts

    Science.gov (United States)

    The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is a major pest of maize, Zea mays L., worldwide. While exploring conventional approaches to management and more recently bioengineering, extended research has been conducted on ways to manage its root-feeding larvae. The nee...

  4. Compensatory Water Effects Link Yearly Global Land CO2 Sink Changes to Temperature

    Science.gov (United States)

    Jung, Martin; Reichstein, Markus; Tramontana, Gianluca; Viovy, Nicolas; Schwalm, Christopher R.; Wang, Ying-Ping; Weber, Ulrich; Weber, Ulrich; Zaehle, Soenke; Zeng, Ning; hide

    2017-01-01

    Large interannual variations in the measured growth rate of atmospheric carbon dioxide (CO2) originate primarily from fluctuations in carbon uptake by land ecosystems13. It remains uncertain, however, to what extent temperature and water availability control the carbon balance of land ecosystems across spatial and temporal scales314. Here we use empirical models based on eddy covariance data15 and process-based models16,17 to investigate the effect of changes in temperature and water availability on gross primary productivity (GPP), terrestrial ecosystem respiration (TER) and net ecosystem exchange (NEE) at local and global scales. We find that water availability is the dominant driver of the local interannual variability in GPP and TER. To a lesser extent this is true also for NEE at the local scale, but when integrated globally, temporal NEE variability is mostly driven by temperature fluctuations. We suggest that this apparent paradox can be explained by two compensatory water effects. Temporal water-driven GPP and TER variations compensate locally, dampening water-driven NEE variability. Spatial water availability anomalies also compensate, leaving a dominant temperature signal in the year-to-year fluctuations of the land carbon sink. These findings help to reconcile seemingly contradictory reports regarding the importance of temperature and water in controlling the interannual variability of the terrestrial carbon balance36,9,11,12,14. Our study indicates that spatial climate covariation drives the global carbon cycle response.

  5. Electrochemical immunosensor based on ensemble of nanoelectrodes for immunoglobulin IgY detection: application to identify hen's egg yolk in tempera paintings.

    Science.gov (United States)

    Bottari, Fabio; Oliveri, Paolo; Ugo, Paolo

    2014-02-15

    A nanostructured electrochemical biosensor for detecting proteins of interest in work of art, in particular in tempera paintings, is presented. To determine egg yolk we focus here on the determination of immunoglobulin IgY. The transducers are nanoelectrode ensembles (NEEs), prepared via membrane templated electroless deposition of gold. Because of their geometrical and diffusion characteristics, NEEs are characterized by significantly low detection limits, moreover they display the capability of capturing proteins by interaction with the polycarbonate membrane of the NEE. At first, the proteic component of the paint is extracted by ultrasonication in an aqueous buffer, then IgY is captured by incubation on the NEE. The immunoglobulin is detected by treatment with anti-IgY labeled with horse radish peroxidase (Anti-IgY-HRP). The binding of the Anti-IgY-HRP is detected by recording the electrocatalytic signal caused by addition of H2O2 and methylene blue. The sensor detection capabilities are tested by analyzing both paint models, prepared in the lab, and real samples, from paintings of the XVIII-XX century. Multivariate exploratory analysis is applied to classify the voltammetric patterns, confirming the capability to differentiate egg-yolk tempera from other kind of tempera binders as well as from acrylic or oil paints. © 2013 Elsevier B.V. All rights reserved.

  6. Use of Glyphosate and Imazapyr for Cogongrass (Imperata cylindrica) management in southern pine forests

    Science.gov (United States)

    Patrick J. Minogue; James H. Miller; Dwight K. Lauer

    2012-01-01

    Cogongrass (Imperata cylindrica [L.] P. Beauv. var. major [Nees] C.E. Hubb) is one of the most invasive perennial grasses worldwide and has progressively infested managed and natural habitats in the mid-South over the past 100 years. To extend past research toward the goal of eradication on forested sites, we tested the most effective herbicides (glyphosate and...

  7. Creating Quality Assurance and International Transparency for Quality Assurance Agencies

    DEFF Research Database (Denmark)

    Kristoffersen, Dorte; Lindeberg, Tobias

    2004-01-01

    The paper presents the experiences gained in the pilot project on mutual recognition conducted by the quality assurance agencies in the Nordic countries and the future perspective for international quality assurance of national quality assurance agencies. The background of the project was the nee...

  8. Similar net ecosystem exchange of beech stands located in France and Denmark

    DEFF Research Database (Denmark)

    Granier, A.; Pilegaard, K.; Jensen, N.O.

    2002-01-01

    Net ecosystem exchange (NEE), as measured with eddy covariance was compared for two European beech stands for the years 1996-1999: a young beech forest (32 year-old) growing in east France, and a mature beech stand (80 year-old) located in Denmark. Those sites are included in the Carboeuroflux...

  9. Photosynthesis drives anomalies in net carbon-exchange of pine forests at different latitudes

    NARCIS (Netherlands)

    Luyssaert, S.; Janssens, I.A.; Sulkava, M.; Papale, D.; Dolman, A.J.; Reichstein, M.; Hollmén, J.; Martin, J.G.; Suni, T.; Vesala, T.; Loustau, D.; Law, B.E.; Moors, E.J.

    2007-01-01

    The growth rate of atmospheric CO2 exhibits large temporal variation that is largely determined by year-to-year fluctuations in land¿atmosphere CO2 fluxes. This land¿atmosphere CO2-flux is driven by large-scale biomass burning and variation in net ecosystem exchange (NEE). Between- and within years,

  10. Distichia acicularis sp. nov. – a new cushion forming Juncaceae from the high Andes of Ecuador

    DEFF Research Database (Denmark)

    Balslev, Henrik; Lægaard, Simon

    1986-01-01

    Distichia acicularis is described as a new species of Juncaceae. It occurs in the high Andes of Ecuador between 3200 m and 4200 m above sea level. Its closest relative is D. muscoides Nees & Meyen from which it is distinct through its narrow, linear, mucronate leafblades and its 1–3 mm long...

  11. Revision of the Euagathis species (Hymenoptera: Braconidae: Bassinae) from the Sunda Islands

    NARCIS (Netherlands)

    Simbolotti, G.; Achterberg, van C.

    1994-01-01

    The species of the genus Euagathis Szépligeti, 1900 (Braconidae: Bassinae (= Agathidinae)) from the Greater and Lesser Sunda Islands (including West Malaysia) are revised and keyed. The subfamily name Bassinae Nees, 1812, is used because it is senior to the commonly used subfamily name Agathidinae

  12. Browse Title Index

    African Journals Online (AJOL)

    Items 151 - 200 of 298 ... Vol 21, No 1 (2013), Hepatoprotective Effect of the Aqueous Leaf Extract of Andrographis paniculata Nees Against Carbon Tetrachloride – Induced ... Influence of Compression Stresses on Timber Potentials of Plantation Grown Eucalyptus camaldulensis Denhn in North-Western Nigeria, Abstract PDF.

  13. Climatic Versus Biotic Constraints on Carbon and Water Fluxes in Seasonally Drought-affected Ponderosa Pine Ecosystems. Chapter 2

    Science.gov (United States)

    Schwarz, P. A.; Law, B. E.; Williams, M.; Irvine, J.; Kurpius, M.; Moore, D.

    2005-01-01

    We investigated the relative importance of climatic versus biotic controls on gross primary production (GPP) and water vapor fluxes in seasonally drought-affected ponderosa pine forests. The study was conducted in young (YS), mature (MS), and old stands (OS) over 4 years at the AmeriFlux Metolius sites. Model simulations showed that interannual variation of GPP did not follow the same trends as precipitation, and effects of climatic variation were smallest at the OS (50%), and intermediate at the YS (drought and interannual climatic variation. Interannual variation of net ecosystem exchange (NEE) was also lowest at the OS, where NEE is controlled more by interannual variation of ecosystem respiration, 70% of which is from soil, than by the variation of GPP, whereas variation in GPP is the primary reason for interannual changes in NEE at the YS and MS. Across spatially heterogeneous landscapes with high frequency of younger stands resulting from natural and anthropogenic disturbances, interannual climatic variation and change in leaf area are likely to result in large interannual variation in GPP and NEE.

  14. Evaluating the Significance of CDK2-PELP1 Axis in Tumorigenesis and Hormone Therapy Resistance

    Science.gov (United States)

    2011-02-01

    Rambabu Challa1, Bramanandam Manavathi3, nee Yew2, Rakesh Kumar4, Rajeshwar Rao Tekmal1, and Ratna K. Vadlamudi1ract Estr influen recept cancer genesi the...breast cancer progression. Cancer Res; 70(18); 7166–75. ©2010 AACR.CDK2 of tum emerg stream crucia Estr prolife glands gressio cycle ductio is prop

  15. Effects of Resin and Essential Oil from Commiphora myrrha Engl. on ...

    African Journals Online (AJOL)

    The oleo-gum-resin of Commiphora myrrha (Nees) Engl (syn. Commiphora molmol (Engl.) Engl. ex Tschirch) is used in the Ethiopian folkloric medicine for wound management. The present study was aimed at evaluating the wound healing properties of the essential oil and resin of C. myrrha using in vivo and in vitro ...

  16. Intertekstualiteit en modernistiese kompleksiteit in Henriette Grové ...

    African Journals Online (AJOL)

    Nee wat, Jan, die wêreld was darem veel meer romanties… (63). En op 10 Oktober van omstreeks 1919, skryf die jong onderwyseres Anne Shirley wat haar verloofde, Gilbert Blythe, 'n mediese student, normaalweg aanspreek as “Gilbert. Dear” of “Dearest” vanaf die huis Windy Willows op Prince Edward Island in Kanada: ...

  17. Revision of the Lauraceae I

    NARCIS (Netherlands)

    Kostermans, A.J.G.H.

    1936-01-01

    Acrodiclidium Nees, Laur. Disp. Progr. (1833), p. 13; id., Syst. Laur. (1836), p. 266; Endl., Gen. (1837), p. 319, n. 2042; id., Ench. (1841), p. 197; Dietrich, Synops. Pl. II (1840), p. 1332; Spach, Hist. nat. Véget., Phaner. X (1841), p. 471; Steudel. Nomencl. ed. 2 (1841), p. 21; Meissn., Gen. I

  18. Revision of the Lauraceae II. The genera Endlicheria, Cryptocarya (American species) and Licaria

    NARCIS (Netherlands)

    Kostermans, A.J.G.H.

    1937-01-01

    Endlicheria Nees (non Presl) in Linnaea 8 (1833), p. 37; id., Progr. (1833), p. 16; id., Syst. (1836), p. 365; Endl., Gen. (1837), p. 321; id., Ench. (1841), p. 197; Dietrich, Synops. Pl. 2 (1840), p. 1332, 1350; Spach, Hist. nat. Végét. X (1841), p. 473; Steudel, Nomencl. ed. 2 (1841), p. 554;

  19. Women in History--Mary Seacole

    Science.gov (United States)

    Harmer, Bonnie

    2005-01-01

    Born in Jamaica in 1805, Mary Seacole (nee Grant), was the daughter of a Black Creole boarding house owner and a Scottish Army officer. Like many Creole doctress women, Seacole was taught African herbal medicine arts from her mother. In addition to understanding traditional herbal medicine, she gleaned an understanding of Western medicine from the…

  20. 76 FR 11821 - Submission for OMB Review; Comment Request Survey of Principal Investigators on Earthquake...

    Science.gov (United States)

    2011-03-03

    ... Submission for OMB Review; Comment Request Survey of Principal Investigators on Earthquake Engineering... Investigators on Earthquake Engineering Research Awards Made by the National Science Foundation, 2003-2009. Type... George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES). The purpose of the proposed...

  1. Complex conductivity response to silver nanoparticles in partially saturated sand columns

    Science.gov (United States)

    The increase in the use of nanoscale materials in consumer products has resulted in a growing concern of their potential hazard to ecosystems and public health from their accidental or intentional introduction to the environment. Key environmental, health, and safety research nee...

  2. community participation in health delivery

    African Journals Online (AJOL)

    Riflcin (1988) summarized the definition of participation to characterize activeness, choice, and the possibility of the choice being ... in a defined geographic area actively pursue identification of their needs, take deci- sions and establish mechanism to meet these nee .... process (needy, 2001). Four community participation ...

  3. Author Details

    African Journals Online (AJOL)

    Okogun, JI. Vol 11 (2006) - Articles Pharmacognostic standardizaion of Andrographis paniculata. Nees. (Acanthaceae) Abstract PDF · Vol 14 (2009) - Articles Phytochemical and Anti-sickling Activities of Terminalia catappa Linn. Abstract PDF. ISSN: 1118-1028. AJOL African Journals Online. HOW TO USE AJOL.

  4. Polyacetylated labdane-type diterpenoids, ptychantins P-R from Chinese liverwort Ptychanthus striatus.

    Science.gov (United States)

    Wu, Jing-Yi; Zhang, Jiao-Zhen; Kang, Ya-Qi; Wang, Xiao; Fan, Pei-Hong; Zhou, Jin-Chuan; Lou, Hong-Xiang

    2015-05-01

    Three new polyacetylated labdane diterpenoids ptychantins P-R (1-3) and four known compounds (4-7) were isolated from an EtOH extract of the Chinese liverwort Ptychanthus striatus (Lehm. & Lindenb.) Nees. Their structures were established by extensive analysis of spectroscopic data (IR, UV, HRESIMS, 1D NMR, and 2D NMR).

  5. Enkele floristische waarnemingen in Midden-Nederland

    NARCIS (Netherlands)

    Floristenclub Gelderse Vallei,

    1978-01-01

    Records from the central part of the Netherlands of adventitious species on their way to or already arrived at the status of naturalization: Amsinckia menziesii (Lehm.) Nels. & Macbr., Egeria densa Planch., Eragrostis capillaris (L.) Nees, Polygonum cilinode Michx., Solanum nitidibaccatum Bitter,

  6. https://www.cancer.gov/publications/dictionaries/cancer-terms

    Science.gov (United States)

    ... by a patient’s immune system. It causes severe, chronic, diarrhea and usually occurs in children. autoimmune hemolytic anemia listen (AW-toh-ih-MYOON hee-moh-LIH-tik uh-NEE-mee-uh) ... patients who have chronic lymphocytic leukemia (CLL). Also called immune complex hemolytic ...

  7. Research Article Special Issue

    African Journals Online (AJOL)

    pc

    2017-10-05

    Oct 5, 2017 ... ABSTRACT. A method in formatting unstructured sent knowledge representation such as RDF is nee paragraph of text using statistical language implementation of RDF entity formation is ap retrieval of the Islamic knowledge. 300 conce with 350 relationships are used as a knowledg of queries from the ...

  8. Measurement-based upscaling of pan Arctic net ecosystem exchange: the PANEEx project

    DEFF Research Database (Denmark)

    Mbufong, Herbert Njuabe; Kusbach, Antonin; Lund, Magnus

    2015-01-01

    The high variability in Arctic tundra net ecosystem exchange (NEE) of carbon (C) can be attributed to the high spatial heterogeneity of Arctic tundra due to the complex topography. Current models of C exchange handle the Arctic as either a single or few ecosystems, responding to environmental cha...

  9. Nanoelectrode ensembles as recognition platform for electrochemical immunosensors.

    Science.gov (United States)

    Mucelli, S Pozzi; Zamuner, M; Tormen, M; Stanta, G; Ugo, P

    2008-07-15

    In this study we demonstrate the possibility to prepare highly sensitive nanostructured electrochemical immunosensors by immobilizing biorecognition elements on nanoelectrode ensembles (NEEs) prepared in track-etch polycarbonate membranes. The gold nanodisk electrodes act as electrochemical transducers while the surrounding polycarbonate binds the antibody-based biorecognition layer. The interaction between target protein and antibody is detected by suitable secondary antibodies labelled with a redox enzyme. A redox mediator, added to the sample solution, shuttles electrons from the nanoelectrodes to the biorecognition layer, so generating an electrocatalytic signal. This allows one to fully exploit the highly improved signal-to-background current ratio, typical of NEEs. In particular, the receptor protein HER2 was studied as the target analyte. HER2 detection allows the identification of breast cancer that can be treated with the monoclonal antibody trastuzumab. NEEs were functionalized with trastuzumab which interacts specifically with HER2. The biorecognition process was completed by adding a primary antibody and a secondary antibody labelled with horseradish peroxidase. Hydrogen peroxide was added to modulate the label electroactivity; methylene blue was the redox mediator generating voltammetric signals. NEEs functionalized with trastuzumab were tested to detect small amounts of HER2 in diluted cell lysates and tumour lysates.

  10. Mass timber rocking panel retrofit of a four-story soft-story building with full-scale shake table validation

    Science.gov (United States)

    Pouria Bahmani; John van de Lindt; Asif Iqbal; Douglas Rammer

    2017-01-01

    Soft-story wood-frame buildings have been recognized as a disaster preparedness problem for decades. There are tens of thousands of these multi-family three- and four-story structures throughout California and the United States. The majority were constructed between 1920 and 1970, with many being prevalent in the San Francisco Bay Area in California. The NEES Soft...

  11. problems in spinning in kolfe house-hold utencil factory abstract ...

    African Journals Online (AJOL)

    and the Dean of the Faculty of Technology for providing the facilities to carry out the investigations. REFERENCES. [1] Johnso~ H. V. Metal Spinning, &nee Publishing. Company, Milwankee. (2] Walker, J.B. Modem Metal Working, The Good. Heart.Wilcox Company, filinois. [3] Reed-Hill, R.E. Physical Metallurgy Principles,.

  12. Geographies of Belonging: The Transnational and Local Involvement of Economically Successful Migrants

    NARCIS (Netherlands)

    M.E. van Bochove (Marianne)

    2012-01-01

    textabstractIf scholars of migration had to pick one word to describe the nature of contemporary migration flows and immigrant populations, many of them would probably choose terms like “diversified,” “differentiated,” or “fragmented” (e.g. Alba and Nee 2003: 213; Castles and Miller 2003: 8;

  13. HIV

    African Journals Online (AJOL)

    Introduction. The·human immunodeficiency virus (HIV) can be transmiHed from one person to onother through the use of non-sterile nee- dles, syringes, and other skin-piercing and invasive instruments. Proper .sterilization of all such instruments is therefore important to prevent its transmission. HIV is very sensitive to ...

  14. Estimating parameters of a forest ecosystem C model with measurements of stocks and fluxes as joint constraints

    Science.gov (United States)

    Andrew D. Richardson; Mathew Williams; David Y. Hollinger; David J.P. Moore; D. Bryan Dail; Eric A. Davidson; Neal A. Scott; Robert S. Evans; Holly. Hughes

    2010-01-01

    We conducted an inverse modeling analysis, using a variety of data streams (tower-based eddy covariance measurements of net ecosystem exchange, NEE, of CO2, chamber-based measurements of soil respiration, and ancillary ecological measurements of leaf area index, litterfall, and woody biomass increment) to estimate parameters and initial carbon (C...

  15. The Mathematics of Symmetrical Factorial Designs

    Indian Academy of Sciences (India)

    The Mathematics of Symmetrical Factorial Designs. Mausumi Bose (nee Sen) obtained her MSc degree in. Statistics from the Calcutta. University and PhD degree from the Indian Statistical. Institute. She is on the faculty of the Indian. Statistical Institute. Her main field of research interest is design and analysis of experiments.

  16. Spatially distributed evapotranspiration estimation using remote sensing and ground-based radiometers over cotton at Maricopa, Arizona

    Science.gov (United States)

    Spatially distributed estimates of evapotranspiration (ET) over agricultural lands could be valuable for water management in arid environments and for monitoring irrigated croplands. In recent year various ET estimation approaches have been developed that utilize remote sense data to provide the nee...

  17. Short Communication: The presence of condensed tannin in the ...

    African Journals Online (AJOL)

    The hypothesis that grasses contain tannin deposits in the leaf epidermal cells was tested using the leaf laminas of a Southern African sourveld grass, Eulalia villosa (Thunb.) Nees. The leaf material was assayed for total phenols, condensed tannin and biologically-active tannins. Catechin equivalents of 57.4 and 76.1 mg g ...

  18. Registration of N614, A3N615, N616, and N617 Shattercane Genetic Stocks with cytoplasmic or nuclear male-sterility and juicy or dry midribs

    Science.gov (United States)

    Four shattercane [Sorghum bicolor subsp. drummondii (Nees ex Steud) de Wet & Harlan] genetic stocks, N614, A3N615, N616, N617 (Reg. No. XXX, PI 665683 to 665686), with A3 cytoplasmic male-sterility or nuclear male-sterility gene ms3 containing either juicy (dd) or dry (DD) culms were developed joint...

  19. Income Attainment During Transformation Processes : A Meta-Analysis of the Market Transition Theory

    NARCIS (Netherlands)

    Verhoeven, Willem-Jan; Jansen, Wim; Dessens, Jos

    2005-01-01

    The changing communist regime in China and the ‘velvet’ revolutions in Central and Eastern Europe (CEE) have provided an opportunity to investigate trends in income attainment during processes of transformation. Nee (1989) formulated the market transition theory, which indicates the main

  20. Contrasting effects of invasive insects and fire on ecosystem water use efficiency

    Science.gov (United States)

    K.L. Clark; N.S. Skowronski; M.R. Gallagher; H. Renninger; K.V.R. Schäfer

    2014-01-01

    We used eddy covariance and meteorological measurements to estimate net ecosystem exchange of CO2 (NEE), gross ecosystem production (GEP), evapotranspiration (Et), and ecosystem water use efficiency (WUEe; calculated as GEP / Et during dry canopy conditions) in three upland forests in the New Jersey Pinelands, USA, that were defoliated by gypsy...

  1. Browse Title Index

    African Journals Online (AJOL)

    Items 201 - 250 of 1250 ... Jing-tao Wu, Gui-wen Yang, Cui-hua Qi, Lei Zhou, Jian-guo Hu, Mao-shan Wang. Vol 8, No 4 (2011), Anti-inflammatory, analgesic and antipyretic effects of Lepidagathis anobrya Nees (Acanthaceae), Abstract PDF. WR Sawadogo, M Lompo, N Somé, IP Guissou, O-G Nacoulma-Ouedraogo.

  2. Carbon dioxide and water vapor exchange in a warm temperate grassland

    Science.gov (United States)

    K.A. Novick; P.C. Stoy; G.G. Katul; D.S. Ellsworth; M.B.S. Siqueira; J. Juang; R. Oren

    2004-01-01

    Grasslands cover about 40% of the ice-free global terrestrial surface, but their contribution to local and regional water and carbon fluxes and sensitivity to climatic perturbations such as drought remains uncertain. Here, we assess the direction and magnitude of net ecosystem carbon exchange (NEE) and it components, ecosystem carbon assimilation (Ac...

  3. Modelling the limits on the response of net carbon exchange to fertilization in a south-eastern pine forest

    Science.gov (United States)

    Chun-Tai. Lai; G. Katul; J. Butnor; M. Siqueira; D. Ellsworth; C. Maier; Kurt Johnsen; S. Mickeand; R. Oren

    2002-01-01

    Using a combination of model simulations and detailed measurements at a hierarchy of scales conducted at a sandhills forest site, the effect of fertilization on net ecosystem exchange (NEE) and its components in 6-year-old Pinus taeda stands was quantified. The detailed measurements, collected over a 20-d period in September and October, included gas...

  4. Evaluation of DoD’s Use of Unmanned Aircraft Systems (UAS) for Support to Civil Authorities (REDACTED)

    Science.gov (United States)

    2015-03-20

    funtl ti C•r pcfi• JCb 11111 1.. nee~ 011c 11) colrnd.tr VI.Al in ld•l!’cc of’ lhe f"’Ol"’>Cd n crti...°’ t.tainin& ~n nnk:r to toNitct J(\\mc ’’~ (’"Cl

  5. Reflections The Early life of Albert Einstein: Seeking the Mature ...

    Indian Academy of Sciences (India)

    was his introduction to music. Albert's mother Pauline, nee Koch, came from a. Stuttgart family of grain merchants with a comfortable financial background. She was a lover and a keen student of classical music and from his sixth year onwards Einstein took lessons on the violin. Early on it may have been a chore but soon he ...

  6. 77 FR 5507 - Turlock Irrigation District, Modesto Irrigation District; Notice of Proposed Restricted Service...

    Science.gov (United States)

    2012-02-03

    ... Energy Regulatory Commission Turlock Irrigation District, Modesto Irrigation District; Notice of Proposed... any Order issuing a license. Turlock Irrigation District and Modesto Irrigation District, as the..., Sacramento, CA 95816. Robert Nees, or Representative, Turlock Irrigation District, P.O. Box 949, Turlock, CA...

  7. Age-dependent changes in ecosystem carbon fluxes in managed forests in Northern Wisconsin, USA

    Science.gov (United States)

    Asko Noormets; Jiquan Chen; Thomas R. Crow

    2007-01-01

    The age-dependent variability of ecosystem carbon (C) fluxes was assessed by measuring the net ecosystem exchange of C (NEE) in five managed forest stands in northern Wisconsin, USA. The study sites ranged in age from 3-year-old clearcut to mature stands (65 years). All stands, except the clearcut, accumulated C over the study period from May to October 2002. Seasonal...

  8. Development of an Implementation Plan for Atmospheric Carbon Monitoring in California

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Marc L.; Riley, William J.; Tonse, Shaheen

    2004-10-01

    This report describes the design of atmospheric CO{sub 2} concentration measurements that, in combination with other measurements and models, would be used to quantify regionally distributed CO{sub 2} exchanges from California's terrestrial ecosystems and CO{sub 2} emissions from fossil fuel combustion. Using models of net ecosystem CO{sub 2} exchange (NEE), fossil fuel CO{sub 2} emissions, and regional meteorology, we predict CO{sub 2} concentration ''signals'' in the atmosphere. The predictions of NEE exhibit spatial and temporal variations that are controlled by land cover and climate. Fossil fuel CO{sub 2} emissions from metropolitan areas are the strongest localized sources of CO{sub 2} while weaker but spatially extensive fossil emissions are present throughout the Central Valley. We subdivide the CO{sub 2} sources into four components: NEE inside and outside CA, and fossil fuel CO{sub 2} inside and outside CA. Maps of predicted atmospheric CO{sub 2} concentration signals from these four sources largely mirror the instantaneous emissions near strong sources but plumes of CO{sub 2} enriched or depleted air are predicted to advect far from their sources. We then identify a baseline set of observing stations from existing and possible future sites that could be used to characterize in-state and out-of-state ecosystem and fossil fuel contributions to atmospheric CO{sub 2} concentrations. For each of the stations we calculate mean midday concentration signals with standard deviation for each month and source. We also calculate the covariance of the signal due to NEE inside CA with each of the other signals to quantify how much of the signal from NEE inside CA might be readily separable from the other signals. On the basis of these predictions, we identify new observing stations and a measurement protocol that, in combination with existing stations, would provide data to estimate NEE within CA. Although beyond the scope of this project

  9. Net ecosystem carbon exchange of a dry temperate eucalypt forest

    Science.gov (United States)

    Hinko-Najera, Nina; Isaac, Peter; Beringer, Jason; van Gorsel, Eva; Ewenz, Cacilia; McHugh, Ian; Exbrayat, Jean-François; Livesley, Stephen J.; Arndt, Stefan K.

    2017-08-01

    Forest ecosystems play a crucial role in the global carbon cycle by sequestering a considerable fraction of anthropogenic CO2, thereby contributing to climate change mitigation. However, there is a gap in our understanding about the carbon dynamics of eucalypt (broadleaf evergreen) forests in temperate climates, which might differ from temperate evergreen coniferous or deciduous broadleaved forests given their fundamental differences in physiology, phenology and growth dynamics. To address this gap we undertook a 3-year study (2010-2012) of eddy covariance measurements in a dry temperate eucalypt forest in southeastern Australia. We determined the annual net carbon balance and investigated the temporal (seasonal and inter-annual) variability in and environmental controls of net ecosystem carbon exchange (NEE), gross primary productivity (GPP) and ecosystem respiration (ER). The forest was a large and constant carbon sink throughout the study period, even in winter, with an overall mean NEE of -1234 ± 109 (SE) g C m-2 yr-1. Estimated annual ER was similar for 2010 and 2011 but decreased in 2012 ranging from 1603 to 1346 g C m-2 yr-1, whereas GPP showed no significant inter-annual variability, with a mean annual estimate of 2728 ± 39 g C m-2 yr-1. All ecosystem carbon fluxes had a pronounced seasonality, with GPP being greatest during spring and summer and ER being highest during summer, whereas peaks in NEE occurred in early spring and again in summer. High NEE in spring was likely caused by a delayed increase in ER due to low temperatures. A strong seasonal pattern in environmental controls of daytime and night-time NEE was revealed. Daytime NEE was equally explained by incoming solar radiation and air temperature, whereas air temperature was the main environmental driver of night-time NEE. The forest experienced unusual above-average annual rainfall during the first 2 years of this 3-year period so that soil water content remained relatively high and the forest

  10. Assessment of Carbon Flux and Soil Moisture in Wetlands Applying Sentinel-1 Data

    Directory of Open Access Journals (Sweden)

    Katarzyna Dabrowska-Zielinska

    2016-09-01

    Full Text Available The objectives of the study were to determine the spatial rate of CO2 flux (Net Ecosystem Exchange and soil moisture in a wetland ecosystem applying Sentinel-1 IW (Interferometric Wide data of VH (Vertical Transmit/Horizontal Receive—cross polarization and VV (Vertical Transmit/Vertical Receive—like polarization polarization. In-situ measurements of carbon flux, soil moisture, and LAI (Leaf Area Index were carried out over the Biebrza Wetland in north-eastern Poland. The impact of soil moisture and LAI on backscattering coefficient (σ° calculated from Sentinel-1 data showed that LAI dominates the influence on σ° when soil moisture is low. The models for soil moisture have been derived for wetland vegetation habitat types applying VH polarization (R2 = 0.70 to 0.76. The vegetation habitats: reeds, sedge-moss, sedges, grass-herbs, and grass were classified using combined one Landsat 8 OLI (Operational Land Imager and three TerraSAR-X (TSX ScanSAR VV data. The model for the assessment of Net Ecosystem Exchange (NEE has been developed based on the assumption that soil moisture and biomass represented by LAI have an influence on it. The σ° VH and σ° VV describe soil moisture and LAI, and have been the input to the NEE model. The model, created for classified habitats, is as follows: NEE = f (σ° Sentinel-1 VH, σ° Sentinel-1 VV. Reasonably good predictions of NEE have been achieved for classified habitats (R2 = 0.51 to 0.58. The developed model has been used for mapping spatial and temporal distribution of NEE over Biebrza wetland habitat types. Eventually, emissions of CO2 to the atmosphere (NEE positive has been noted when soil moisture (SM and biomass were low. This study demonstrates the importance of the capability of Sentinel-1 microwave data to calculate soil moisture and estimate NEE with all-weather acquisition conditions, offering an important advantage for frequent wetlands monitoring.

  11. Differences in plant cover and species composition of semiarid grassland communities of central Mexico and its effects on net ecosystem exchange

    Directory of Open Access Journals (Sweden)

    J. Delgado-Balbuena

    2013-07-01

    Full Text Available Changes in land use across the semiarid grasslands of northern Mexico have driven a decline of plant cover and alteration of plant species composition. A number of different plant communities have resulted from these changes. Their implications, however, on the carbon (C cycle and regional carbon balance are still poorly understood. Here, we examined the effects of plant cover loss and changes in species composition on net ecosystem CO2 exchange (NEE and their biotic and abiotic controls. NEE was measured in five representative plant community types within a semiarid grassland by temporarily enclosing the entire aboveground ecosystem using a chamber method (i.e., geodesic dome. Sites included an oat crop (crop, a moderately grazed grassland (moderate grazing, a 28 yr-old grazing exclosure (exclosure, an overgrazed site with low perennial grass cover (overgrazed, and an overgrazed site presenting shrub encroachment (shrub encroachment. For natural vegetation, rates of standardized daytime NEE for sites with a high plant cover (exclosure and moderate grazing were similar (P > 0.05 as compared to sites with low plant cover (overgrazed and shrub encroachment. However, yearly total nighttime NEE (carbon loss was more than double (P < 0.05 for sites with high plant cover compared to sites with low cover, resulting to slight C sinks for the low plant cover sites, and neutral or sources for the high plant cover sites as accounted by daytime and nighttime NEE annual balance. Differences in plant cover and its associated biomass defined the sensitivity to environmental controls. Thus, daytime NEE in low plant cover sites reached light compensation points at lower photosynthetic photon flux density than those from high plant cover sites. Differences in species composition did not influence NEE rates even though there were transient or permanent changes in C3 vs. C4 functional groups. Our results allowed the detection of the large variability and

  12. Net ecosystem production in a Little Ice Age moraine: the role of plant functional traits

    Science.gov (United States)

    Varolo, E.; Zanotelli, D.; Tagliavini, M.; Zerbe, S.; Montagnani, L.

    2015-07-01

    Current glacier retreat allows vast mountain ranges available for vegetation establishment and growth. Little is known about the effective carbon (C) budget of these new ecosystems and how the presence of different vegetation communities, characterized by their specific physiology and life forms influences C fluxes. In this study, using a comparative analysis of the C fluxes of two contrasting vegetation types, we intend to evaluate if the different physiologies of the main species have an effect on Ecosystem Respiration (Reco), Gross Primary Production (GPP), annual cumulated Net Ecosystem Exchange (NEE), and long-term carbon accumulation in soil. The NEE of two plant communities present on a Little Ice Age moraine in the Matsch glacier forefield (Alps, Italy) was measured over two growing seasons. They are a typical C3 grassland, dominated by Festuca halleri All. and a community dominated by CAM rosettes Sempervivum montanum L. on rocky soils. Using transparent and opaque chambers, we extrapolated the ecophysiological responses to the main environmental drivers and performed the partition of NEE into Reco and GPP. Soil samples were collected from the same site to measure long-term C accumulation in the ecosystem. The two communities showed contrasting GPP but similar Reco patterns and as a result significantly different in NEE. The grassland acted mainly as a carbon sink with a total cumulated value of -46.4 ± 35.5 g C m-2 NEE while the plots dominated by the CAM rosettes acted as a source with 31.9 ± 22.4 g C m-2. In spite of the NEE being different in the two plant communities, soil analysis did not reveal significant differences in carbon accumulation. Grasslands showed 1.76 ± 0.12 kg C m-2, while CAM rosettes showed 2.06 ± 0.23 kg C m-2. This study demonstrates that carbon dynamics of two vegetation communities can be distinct even though the growing environment is similar. The physiological traits of the dominant species determine large differences in

  13. Net ecosystem carbon exchange of a dry temperate eucalypt forest

    Directory of Open Access Journals (Sweden)

    N. Hinko-Najera

    2017-08-01

    Full Text Available Forest ecosystems play a crucial role in the global carbon cycle by sequestering a considerable fraction of anthropogenic CO2, thereby contributing to climate change mitigation. However, there is a gap in our understanding about the carbon dynamics of eucalypt (broadleaf evergreen forests in temperate climates, which might differ from temperate evergreen coniferous or deciduous broadleaved forests given their fundamental differences in physiology, phenology and growth dynamics. To address this gap we undertook a 3-year study (2010–2012 of eddy covariance measurements in a dry temperate eucalypt forest in southeastern Australia. We determined the annual net carbon balance and investigated the temporal (seasonal and inter-annual variability in and environmental controls of net ecosystem carbon exchange (NEE, gross primary productivity (GPP and ecosystem respiration (ER. The forest was a large and constant carbon sink throughout the study period, even in winter, with an overall mean NEE of −1234 ± 109 (SE g C m−2 yr−1. Estimated annual ER was similar for 2010 and 2011 but decreased in 2012 ranging from 1603 to 1346 g C m−2 yr−1, whereas GPP showed no significant inter-annual variability, with a mean annual estimate of 2728 ± 39 g C m−2 yr−1. All ecosystem carbon fluxes had a pronounced seasonality, with GPP being greatest during spring and summer and ER being highest during summer, whereas peaks in NEE occurred in early spring and again in summer. High NEE in spring was likely caused by a delayed increase in ER due to low temperatures. A strong seasonal pattern in environmental controls of daytime and night-time NEE was revealed. Daytime NEE was equally explained by incoming solar radiation and air temperature, whereas air temperature was the main environmental driver of night-time NEE. The forest experienced unusual above-average annual rainfall during the first 2 years of this 3-year period so

  14. Turbulence Considerations for Comparing Ecosystem Exchange over Old-Growth and Clear-Cut Stands For Limited Fetch and Complex Canopy Flow Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wharton, S; Schroeder, M; Paw U, K T; Falk, M; Bible, K

    2009-01-08

    Carbon dioxide, water vapor and energy fluxes were measured using eddy covariance (EC) methodology over three adjacent forests in southern Washington State to identify stand-level age-effects on ecosystem exchange. The sites represent Douglas-fir forest ecosystems at two contrasting successional stages: old-growth (OG) and early seral (ES). Here we present eddy flux and meteorological data from two early seral stands and the Wind River AmeriFlux old-growth forest during the growing season (March-October) in 2006 and 2007. We show an alternative approach to the usual friction velocity (u*) method for determining periods of adequate atmospheric boundary layer (ABL) mixing based on the ratio of mean horizontal ({bar u}) and vertical ({bar w}) wind flow to a modified turbulent kinetic energy scale (uTKE). This new parameter in addition to footprint modeling showed that daytime CO{sub 2} fluxes (F{sub NEE}) in small clear-cuts (< 10 hectares) can be measured accurately with EC if micrometeorological conditions are carefully evaluated. Peak midday CO{sub 2} fluxes (F{sub NEE} = -14.0 to -12.3 {micro}mol m{sup -2} s{sup -1}) at OG were measured in April in both 2006 and 2007 before bud break when air and soil temperatures and vapor pressure deficit were relatively low, and soil moisture and light levels were favorable for photosynthesis. At the early seral stands, peak midday CO{sub 2} fluxes (F{sub NEE} = -11.0 to -8.7 {micro}mol m{sup -2} s{sup -1}) were measured in June and July while spring-time CO{sub 2} fluxes were much smaller (F{sub NEE} = -3.8 to -3.6 {micro}mol m{sup -2} s{sup -1}). Overall, we measured lower evapotranspiration (OG = 230 mm; ES = 297 mm) higher midday F{sub NEE} (OG F{sub NEE} = -9.0 {micro}mol m{sup -2} s{sup -1}; ES F{sub NEE} = -7.3 {micro}mol m{sup -2} s{sup -1}) and higher Bowen ratios (OG {beta} = 2.0. ES {beta} = 1.2) at the old-growth forest than at the ES sites during the summer months (May-August). Eddy covariance studies such as ours

  15. Carbon and energy fluxes in cropland ecosystems: a model-data comparison

    Science.gov (United States)

    Lokupitiya, E.; Denning, A.S.; Schaefer, K.; Ricciuto, D.; Anderson, R.; Arain, M. A.; Baker, I.; Barr, A. G.; Chen, G.; Chen, J.M.; Ciais, P.; Cook, D.R.; Dietze, M.C.; El Maayar, M.; Fischer, M.; Grant, R.; Hollinger, D.; Izaurralde, C.; Jain, A.; Kucharik, C.J.; Li, Z.; Liu, S.; Li, L.; Matamala, R.; Peylin, P.; Price, D.; Running, S. W.; Sahoo, A.; Sprintsin, M.; Suyker, A.E.; Tian, H.; Tonitto, Christina; Torn, M.S.; Verbeeck, Hans; Verma, S.B.; Xue, Y.

    2016-01-01

    Croplands are highly productive ecosystems that contribute to land–atmosphere exchange of carbon, energy, and water during their short growing seasons. We evaluated and compared net ecosystem exchange (NEE), latent heat flux (LE), and sensible heat flux (H) simulated by a suite of ecosystem models at five agricultural eddy covariance flux tower sites in the central United States as part of the North American Carbon Program Site Synthesis project. Most of the models overestimated H and underestimated LE during the growing season, leading to overall higher Bowen ratios compared to the observations. Most models systematically under predicted NEE, especially at rain-fed sites. Certain crop-specific models that were developed considering the high productivity and associated physiological changes in specific crops better predicted the NEE and LE at both rain-fed and irrigated sites. Models with specific parameterization for different crops better simulated the inter-annual variability of NEE for maize-soybean rotation compared to those models with a single generic crop type. Stratification according to basic model formulation and phenological methodology did not explain significant variation in model performance across these sites and crops. The under prediction of NEE and LE and over prediction of H by most of the models suggests that models developed and parameterized for natural ecosystems cannot accurately predict the more robust physiology of highly bred and intensively managed crop ecosystems. When coupled in Earth System Models, it is likely that the excessive physiological stress simulated in many land surface component models leads to overestimation of temperature and atmospheric boundary layer depth, and underestimation of humidity and CO2 seasonal uptake over agricultural regions.

  16. Biosphere-atmosphere exchange of CO2 in relation to climate: a cross-biome analysis across multiple time scales

    Directory of Open Access Journals (Sweden)

    L. Montagnani

    2009-10-01

    Full Text Available The net ecosystem exchange of CO2 (NEE varies at time scales from seconds to years and longer via the response of its components, gross ecosystem productivity (GEP and ecosystem respiration (RE, to physical and biological drivers. Quantifying the relationship between flux and climate at multiple time scales is necessary for a comprehensive understanding of the role of climate in the terrestrial carbon cycle. Orthonormal wavelet transformation (OWT can quantify the strength of the interactions between gappy eddy covariance flux and micrometeorological measurements at multiple frequencies while expressing time series variance in few energetic wavelet coefficients, offering a low-dimensional view of the response of terrestrial carbon flux to climatic variability. The variability of NEE, GEP and RE, and their co-variability with dominant climatic drivers, are explored with nearly one thousand site-years of data from the FLUXNET global dataset consisting of 253 eddy covariance research sites. The NEE and GEP wavelet spectra were similar among plant functional types (PFT at weekly and shorter time scales, but significant divergence appeared among PFT at the biweekly and longer time scales, at which NEE and GEP were relatively less variable than climate. The RE spectra rarely differed among PFT across time scales as expected. On average, RE spectra had greater low frequency (monthly to interannual variability than NEE, GEP and climate. CANOAK ecosystem model simulations demonstrate that "multi-annual" spectral peaks in flux may emerge at low (4+ years time scales. Biological responses to climate and other internal system dynamics, rather than direct ecosystem response to climate, provide the likely explanation for observed multi-annual variability, but data records must be lengthened and measurements of ecosystem state must be made, and made available, to disentangle the mechanisms responsible for low frequency patterns in ecosystem CO2 exchange.

  17. Modification of nanoelectrode ensembles by thiols and disulfides to prevent non specific adsorption of proteins

    Energy Technology Data Exchange (ETDEWEB)

    Silvestrini, M. [Department of Molecular Sciences and Nanosystems, University Ca' Foscari of Venice, Santa Marta 2137, 30123 Venice (Italy); Schiavuta, P.; Scopece, P. [Associazione CIVEN, via delle Industrie 5, 30175 Marghera - Venice (Italy); Pecchielan, G.; Moretto, L.M. [Department of Molecular Sciences and Nanosystems, University Ca' Foscari of Venice, Santa Marta 2137, 30123 Venice (Italy); Ugo, P., E-mail: ugo@unive.it [Department of Molecular Sciences and Nanosystems, University Ca' Foscari of Venice, Santa Marta 2137, 30123 Venice (Italy)

    2011-09-01

    Highlights: > Complex nanostructures are built on the gold surface of ensembles of nanoelectrodes. > Gold surface of nanoelectrodes was functionalized with SAM of organic sulphurs. > The polycarbonate surrounding nanoelectrodes was functionalized with proteins. > SAMs protect the nanoelectrodes from undesired proteins adsorption. - Abstract: The possibility to functionalize selectively with thiols or disulfides the surface of the gold nanoelectrodes of polycarbonate templated nanoelectrode ensembles (NEEs) is studied. It is shown that the Au nanoelectrodes can be coated by a self assembled monolayer (SAM) of thioctic acid (TA) or 2-mercaptoethanesulfonic (MES) acid. The study of the electrochemical behavior of SAM-modified NEEs by cyclic voltammetry (CV) at different solution pH, using ferrocenecarboxylate as an anionic redox probe (FcCOO{sup -}) and (ferrocenylmethyl)trimethylammonium (FA{sup +}) as a cationic redox probe, demonstrate that the SAM-modified nanoelectrodes are permselective, in that only cationic or neutral probes can access the SAM-coated nanoelectrode surface. CV, AFM and FTIR-ATR data indicate that proteins such as casein or bovine serum albumin, which are polyanionic at pH 7, adsorb on the surface of NEEs untreated with thiols, tending to block the electron transfer of the ferrocenyl redox probes. On the contrary, the pre-treatment of the NEE with an anionic SAM protects the nanoelectrodes from protein fouling, allowing the detection of well shaped voltammetric patterns for the redox probe. Experimental results indicate that, in the case of MES treated NEEs, the protein is bound only onto the polycarbonate surface which surrounds the nanoelectrodes, while the tips of the gold nanoelectrodes remain protein free.

  18. Carbon and energy fluxes in cropland ecosystems: a model-data comparison

    Energy Technology Data Exchange (ETDEWEB)

    Lokupitiya, E.; Denning, A. S.; Schaefer, K.; Ricciuto, D.; Anderson, R.; Arain, M. A.; Baker, I.; Barr, A. G.; Chen, G.; Chen, J. M.; Ciais, P.; Cook, D. R.; Dietze, M.; El Maayar, M.; Fischer, M.; Grant, R.; Hollinger, D.; Izaurralde, C.; Jain, A.; Kucharik, C.; Li, Z.; Liu, S.; Li, L.; Matamala, R.; Peylin, P.; Price, D.; Running, S. W.; Sahoo, A.; Sprintsin, M.; Suyker, A. E.; Tian, H.; Tonitto, C.; Torn, M.; Verbeeck, Hans; Verma, S. B.; Xue, Y.

    2016-06-03

    Croplands are highly productive ecosystems that contribute to land–atmosphere exchange of carbon, energy, and water during their short growing seasons. We evaluated and compared net ecosystem exchange (NEE), latent heat flux (LE), and sensible heat flux (H) simulated by a suite of ecosystem models at five agricultural eddy covariance flux tower sites in the central United States as part of the North American Carbon Program Site Synthesis project. Most of the models overestimated H and underestimated LE during the growing season, leading to overall higher Bowen ratios compared to the observations. Most models systematically under predicted NEE, especially at rain-fed sites. Certain crop-specific models that were developed considering the high productivity and associated physiological changes in specific crops better predicted the NEE and LE at both rain-fed and irrigated sites. Models with specific parameterization for different crops better simulated the inter-annual variability of NEE for maize-soybean rotation compared to those models with a single generic crop type. Stratification according to basic model formulation and phenological methodology did not explain significant variation in model performance across these sites and crops. The under prediction of NEE and LE and over prediction of H by most of the models suggests that models developed and parameterized for natural ecosystems cannot accurately predict the more robust physiology of highly bred and intensively managed crop ecosystems. When coupled in Earth System Models, it is likely that the excessive physiological stress simulated in many land surface component models leads to overestimation of temperature and atmospheric boundary layer depth, and underestimation of humidity and CO2 seasonal uptake over agricultural regions.

  19. Competition is constitutional: Four fallacies in the argument that transmission access constitutes a taking

    Energy Technology Data Exchange (ETDEWEB)

    Schotland, S.D. [Gottlieb, Steen & Hamilton, Washington, DC (United States)

    1996-11-01

    New transmission regulations may cause a change in property value or property access, however, this alone does not constitute a regulatory taking. In an industry with a long history of regulation and some degree of shared transmission access, the utilities are going to be hard pressed to show that recent open access mandates are in violation of the Takings Clause of the Fifth Amendment. In a recent article, John Rowe and Paige Graening of the NEES Companies argued that transmission access is the twentieth century equivalent of {open_quotes}piracy{close_quotes} - forcing utilities to provide transmission access to third parties violates the Taking Clause of the Fifth Amendment. The authors stated that transmission access represents a permanent physical invasion of property - which is unconstitutional without {open_quotes}just compensation.{close_quotes} The same arguments have been raised by Michigan utilities in a pending court challenge to the retail wheeling experiment ordered by the Michigan Public Service Commission. Rowe and Graening complain that {open_quotes}under the Jolly Roger of open competition{close_quotes} regulators will limit utilities to {open_quotes}mere embedded costs,{close_quotes} thereby committing an act of {open_quotes}piracy.{close_quotes} Contrary to Rowe and Graening`s claim, the flag of competition is better represented by the Stars and Stripes, since orders to provide transmission access at the cost of service do not result in a regulatory taking. Four fallacies led NEES down the gangplank: (1) The authors argued that reductions in the value of an investment are necessarily takings. Regulatory impairment of property value is a fact of life. (2) Contrary to NEES, transmission access does not effect a permanent physical invasion of property. (3) NEES claimed that transmission access defeats reasonable investment expectations. (4) NEES relied on case law that affords utilities the opportunity to realize a profit.

  20. On the difference in the net ecosystem exchange of CO2 between deciduous and evergreen forests in the southeastern United States.

    Science.gov (United States)

    Novick, Kimberly A; Oishi, A Christopher; Ward, Eric J; Siqueira, Mario B S; Juang, Jehn-Yih; Stoy, Paul C

    2015-02-01

    The southeastern United States is experiencing a rapid regional increase in the ratio of pine to deciduous forest ecosystems at the same time it is experiencing changes in climate. This study is focused on exploring how these shifts will affect the carbon sink capacity of southeastern US forests, which we show here are among the strongest carbon sinks in the continental United States. Using eight-year-long eddy covariance records collected above a hardwood deciduous forest (HW) and a pine plantation (PP) co-located in North Carolina, USA, we show that the net ecosystem exchange of CO2 (NEE) was more variable in PP, contributing to variability in the difference in NEE between the two sites (ΔNEE) at a range of timescales, including the interannual timescale. Because the variability in evapotranspiration (ET) was nearly identical across the two sites over a range of timescales, the factors that determined the variability in ΔNEE were dominated by those that tend to decouple NEE from ET. One such factor was water use efficiency, which changed dramatically in response to drought and also tended to increase monotonically in nondrought years (P temperate climates. Additional variability in the fluxes at long-time scales may be attributable to slowly evolving factors, including canopy structure and increases in dormant season air temperature. Taken together, study results suggest that the carbon sink in the southeastern United States may become more variable in the future, owing to a predicted increase in drought frequency and an increase in the fractional cover of southern pines. © 2014 John Wiley & Sons Ltd.

  1. Land use affects the net ecosystem CO2 exchange and its components in mountain grasslands

    Science.gov (United States)

    Schmitt, M.; Bahn, M.; Wohlfahrt, G.; Tappeiner, U.; Cernusca, A.

    2010-08-01

    Changes in land use and management have been strongly affecting mountain grassland, however, their effects on the net ecosystem exchange of CO2 (NEE) and its components have not yet been well documented. We analysed chamber-based estimates of NEE, gross primary productivity (GPP), ecosystem respiration (R) and light use efficiency (LUE) of six mountain grasslands differing in land use and management, and thus site fertility, for the growing seasons of 2002 to 2008. The main findings of the study are that: (1) land use and management affected seasonal NEE, GPP and R, which all decreased from managed to unmanaged grasslands; (2) these changes were explained by differences in leaf area index (LAI), biomass and leaf-area-independent changes that were likely related to photosynthetic physiology; (3) diurnal variations of NEE were primarily controlled by photosynthetically active photon flux density and soil and air temperature; seasonal variations were associated with changes in LAI; (4) parameters of light response curves were generally closely related to each other, and the ratio of R at a reference temperature/ maximum GPP was nearly constant across the sites; (5) similarly to our study, maximum GPP and R for other grasslands on the globe decreased with decreasing land use intensity, while their ratio remained remarkably constant. We conclude that decreasing intensity of management and, in particular, abandonment of mountain grassland lead to a decrease in NEE and its component processes. While GPP and R are generally closely coupled during most of the growing season, GPP is more immediately and strongly affected by land management (mowing, grazing) and season. This suggests that management and growing season length, as well as their possible future changes, may play an important role for the annual C balance of mountain grassland.

  2. Land use affects the net ecosystem CO2 exchange and its components in mountain grasslands

    Directory of Open Access Journals (Sweden)

    A. Cernusca

    2010-08-01

    Full Text Available Changes in land use and management have been strongly affecting mountain grassland, however, their effects on the net ecosystem exchange of CO2 (NEE and its components have not yet been well documented. We analysed chamber-based estimates of NEE, gross primary productivity (GPP, ecosystem respiration (R and light use efficiency (LUE of six mountain grasslands differing in land use and management, and thus site fertility, for the growing seasons of 2002 to 2008. The main findings of the study are that: (1 land use and management affected seasonal NEE, GPP and R, which all decreased from managed to unmanaged grasslands; (2 these changes were explained by differences in leaf area index (LAI, biomass and leaf-area-independent changes that were likely related to photosynthetic physiology; (3 diurnal variations of NEE were primarily controlled by photosynthetically active photon flux density and soil and air temperature; seasonal variations were associated with changes in LAI; (4 parameters of light response curves were generally closely related to each other, and the ratio of R at a reference temperature/ maximum GPP was nearly constant across the sites; (5 similarly to our study, maximum GPP and R for other grasslands on the globe decreased with decreasing land use intensity, while their ratio remained remarkably constant. We conclude that decreasing intensity of management and, in particular, abandonment of mountain grassland lead to a decrease in NEE and its component processes. While GPP and R are generally closely coupled during most of the growing season, GPP is more immediately and strongly affected by land management (mowing, grazing and season. This suggests that management and growing season length, as well as their possible future changes, may play an important role for the annual C balance of mountain grassland.

  3. Cyclic occurrence of fire and its role in carbon dynamics along an edaphic moisture gradient in longleaf pine ecosystems.

    Directory of Open Access Journals (Sweden)

    Andrew Whelan

    Full Text Available Fire regulates the structure and function of savanna ecosystems, yet we lack understanding of how cyclic fire affects savanna carbon dynamics. Furthermore, it is largely unknown how predicted changes in climate may impact the interaction between fire and carbon cycling in these ecosystems. This study utilizes a novel combination of prescribed fire, eddy covariance (EC and statistical techniques to investigate carbon dynamics in frequently burned longleaf pine savannas along a gradient of soil moisture availability (mesic, intermediate and xeric. This research approach allowed us to investigate the complex interactions between carbon exchange and cyclic fire along the ecological amplitude of longleaf pine. Over three years of EC measurement of net ecosystem exchange (NEE show that the mesic site was a net carbon sink (NEE = -2.48 tonnes C ha(-1, while intermediate and xeric sites were net carbon sources (NEE = 1.57 and 1.46 tonnes C ha(-1, respectively, but when carbon losses due to fuel consumption were taken into account, all three sites were carbon sources (10.78, 7.95 and 9.69 tonnes C ha(-1 at the mesic, intermediate and xeric sites, respectively. Nonetheless, rates of NEE returned to pre-fire levels 1-2 months following fire. Consumption of leaf area by prescribed fire was associated with reduction in NEE post-fire, and the system quickly recovered its carbon uptake capacity 30-60 days post fire. While losses due to fire affected carbon balances on short time scales (instantaneous to a few months, drought conditions over the final two years of the study were a more important driver of net carbon loss on yearly to multi-year time scales. However, longer-term observations over greater environmental variability and additional fire cycles would help to more precisely examine interactions between fire and climate and make future predictions about carbon dynamics in these systems.

  4. Evaluation of the DayCent model to predict carbon fluxes in French crop sites

    Science.gov (United States)

    Fujisaki, Kenji; Martin, Manuel P.; Zhang, Yao; Bernoux, Martial; Chapuis-Lardy, Lydie

    2017-04-01

    Croplands in temperate regions are an important component of the carbon balance and can act as a sink or a source of carbon, depending on pedoclimatic conditions and management practices. Therefore the evaluation of carbon fluxes in croplands by modelling approach is relevant in the context of global change. This study was part of the Comete-Global project funded by the multi-Partner call FACCE JPI. Carbon fluxes, net ecosystem exchange (NEE), leaf area index (LAI), biomass, and grain production were simulated at the site level in three French crop experiments from the CarboEurope project. Several crops were studied, like winter wheat, rapeseed, barley, maize, and sunflower. Daily NEE was measured with eddy covariance and could be partitioned between gross primary production (GPP) and total ecosystem respiration (TER). Measurements were compared to DayCent simulations, a process-based model predicting plant production and soil organic matter turnover at daily time step. We compared two versions of the model: the original one with a simplified plant module and a newer version that simulates LAI. Input data for modelling were soil properties, climate, and management practices. Simulations of grain yields and biomass production were acceptable when using optimized crop parameters. Simulation of NEE was also acceptable. GPP predictions were improved with the newer version of the model, eliminating temporal shifts that could be observed with the original model. TER was underestimated by the model. Predicted NEE was more sensitive to soil tillage and nitrogen applications than measured NEE. DayCent was therefore a relevant tool to predict carbon fluxes in French crops at the site level. The introduction of LAI in the model improved its performance.

  5. Ecosystem CO2/H2O fluxes are explained by hydraulically limited gas exchange during tree mortality from spruce bark beetles

    Science.gov (United States)

    Frank, John M.; Massman, William J.; Ewers, Brent E.; Huckaby, Laurie S.; Negrón, José F.

    2014-06-01

    Disturbances are increasing globally due to anthropogenic changes in land use and climate. This study determines whether a disturbance that affects the physiology of individual trees can be used to predict the response of the ecosystem by weighing two competing hypothesis at annual time scales: (a) changes in ecosystem fluxes are proportional to observable patterns of mortality or (b) to explain ecosystem fluxes the physiology of dying trees must also be incorporated. We evaluate these hypotheses by analyzing 6 years of eddy covariance flux data collected throughout the progression of a spruce beetle (Dendroctonus rufipennis) epidemic in a Wyoming Engelmann spruce (Picea engelmannii)-subalpine fir (Abies lasiocarpa) forest and testing for changes in canopy conductance (gc), evapotranspiration (ET), and net ecosystem exchange (NEE) of CO2. We predict from these hypotheses that (a) gc, ET, and NEE all diminish (decrease in absolute magnitude) as trees die or (b) that (1) gc and ET decline as trees are attacked (hydraulic failure from beetle-associated blue-stain fungi) and (2) NEE diminishes both as trees are attacked (restricted gas exchange) and when they die. Ecosystem fluxes declined as the outbreak progressed and the epidemic was best described as two phases: (I) hydraulic failure caused restricted gc, ET (28 ± 4% decline, Bayesian posterior mean ± standard deviation), and gas exchange (NEE diminished 13 ± 6%) and (II) trees died (NEE diminished 51 ± 3% with minimal further change in ET to 36 ± 4%). These results support hypothesis b and suggest that model predictions of ecosystem fluxes following massive disturbances must be modified to account for changes in tree physiological controls and not simply observed mortality.

  6. New data-driven estimation of terrestrial CO2 fluxes in Asia using a standardized database of eddy covariance measurements, remote sensing data, and support vector regression

    Science.gov (United States)

    Ichii, Kazuhito; Ueyama, Masahito; Kondo, Masayuki; Saigusa, Nobuko; Kim, Joon; Alberto, Ma. Carmelita; Ardö, Jonas; Euskirchen, Eugénie S.; Kang, Minseok; Hirano, Takashi; Joiner, Joanna; Kobayashi, Hideki; Marchesini, Luca Belelli; Merbold, Lutz; Miyata, Akira; Saitoh, Taku M.; Takagi, Kentaro; Varlagin, Andrej; Bret-Harte, M. Syndonia; Kitamura, Kenzo; Kosugi, Yoshiko; Kotani, Ayumi; Kumar, Kireet; Li, Sheng-Gong; Machimura, Takashi; Matsuura, Yojiro; Mizoguchi, Yasuko; Ohta, Takeshi; Mukherjee, Sandipan; Yanagi, Yuji; Yasuda, Yukio; Zhang, Yiping; Zhao, Fenghua

    2017-04-01

    The lack of a standardized database of eddy covariance observations has been an obstacle for data-driven estimation of terrestrial CO2 fluxes in Asia. In this study, we developed such a standardized database using 54 sites from various databases by applying consistent postprocessing for data-driven estimation of gross primary productivity (GPP) and net ecosystem CO2 exchange (NEE). Data-driven estimation was conducted by using a machine learning algorithm: support vector regression (SVR), with remote sensing data for 2000 to 2015 period. Site-level evaluation of the estimated CO2 fluxes shows that although performance varies in different vegetation and climate classifications, GPP and NEE at 8 days are reproduced (e.g., r2 = 0.73 and 0.42 for 8 day GPP and NEE). Evaluation of spatially estimated GPP with Global Ozone Monitoring Experiment 2 sensor-based Sun-induced chlorophyll fluorescence shows that monthly GPP variations at subcontinental scale were reproduced by SVR (r2 = 1.00, 0.94, 0.91, and 0.89 for Siberia, East Asia, South Asia, and Southeast Asia, respectively). Evaluation of spatially estimated NEE with net atmosphere-land CO2 fluxes of Greenhouse Gases Observing Satellite (GOSAT) Level 4A product shows that monthly variations of these data were consistent in Siberia and East Asia; meanwhile, inconsistency was found in South Asia and Southeast Asia. Furthermore, differences in the land CO2 fluxes from SVR-NEE and GOSAT Level 4A were partially explained by accounting for the differences in the definition of land CO2 fluxes. These data-driven estimates can provide a new opportunity to assess CO2 fluxes in Asia and evaluate and constrain terrestrial ecosystem models.

  7. Seasonal effects of irrigation on land-atmosphere latent heat, sensible heat, and carbon fluxes in semiarid basin

    Science.gov (United States)

    Zeng, Yujin; Xie, Zhenghui; Liu, Shuang

    2017-02-01

    Irrigation, which constitutes ˜ 70 % of the total amount of freshwater consumed by the human population, is significantly impacting land-atmosphere fluxes. In this study, using the improved Community Land Model version 4.5 (CLM4.5) with an active crop model, two high-resolution (˜ 1 km) simulations investigating the effects of irrigation on latent heat (LH), sensible heat (SH), and carbon fluxes (or net ecosystem exchange, NEE) from land to atmosphere in the Heihe River basin in northwestern China were conducted using a high-quality irrigation dataset compiled from 1981 to 2013. The model output and measurements from remote sensing demonstrated the capacity of the developed models to reproduce ecological and hydrological processes. The results revealed that the effects of irrigation on LH and SH are strongest during summer, with a LH increase of ˜ 100 W m-2 and a SH decrease of ˜ 60 W m-2 over intensely irrigated areas. However, the reactions are much weaker during spring and autumn when there is much less irrigation. When the irrigation rate is below 5 mm day-1, the LH generally increases, whereas the SH decreases with growing irrigation rates. However, when the irrigation threshold is in excess of 5 mm day-1, there is no accrued effect of irrigation on the LH and SH. Irrigation produces opposite effects to the NEE during spring and summer. During the spring, irrigation yields more discharged carbon from the land to the atmosphere, increasing the NEE value by 0.4-0.8 gC m-2 day-1, while the summer irrigation favors crop fixing of carbon from atmospheric CO2, decreasing the NEE value by ˜ 0.8 gC m-2 day-1. The repercussions of irrigation on land-atmosphere fluxes are not solely linked to the irrigation amount, and other parameters (especially the temperature) also control the effects of irrigation on LH, SH, and NEE.

  8. Variability of annual CO2 exchange from Dutch grasslands

    Directory of Open Access Journals (Sweden)

    A. Schrier-Uijl

    2007-10-01

    Full Text Available An intercomparison is made of the Net Ecosystem Exchange of CO2, NEE, for eight Dutch grassland sites: four natural grasslands, two production grasslands and two meteorological stations within a rotational grassland region. At all sites the NEE was determined during at least 10 months per site, using the eddy-covariance (EC technique, but in different years. The NEE does not include any import or export other than CO2. The photosynthesis-light response analysis technique is used along with the respiration-temperature response technique to partition NEE into Gross Primary Production (GPP and Ecosystem Respiration (Re and to obtain the eco-physiological characteristics of the sites at the field scale. Annual sums of NEE, GPP and Re are then estimated using the fitted response curves with observed radiation and air temperature from a meteorological site in the centre of The Netherlands as drivers. These calculations are carried out for four years (2002–2005. Land use and management histories are not considered. The estimated annual Re for all individual sites is more or less constant per site and the average for all sites amounts to 1390±30 gC m−2 a−1. The narrow uncertainty band (±2% reflects the small differences in the mean annual air temperature. The mean annual GPP was estimated to be 1325 g C m−2 a−1, and displays a much higher standard deviation, of ±110 gC m−2 a−1 (8%, which reflects the relatively large variation in annual solar radiation. The mean annual NEE amounts to –65±85 gC m−2 a−1. From two sites, four-year records of CO2 flux were available and analyzed (2002–2005. Using the weather record of 2005 with optimizations from the other years, the standard deviation of annual GPP was estimated to be 171–206 gC m−2 a−1 (8–14%, of annual Re 227–247 gC m−2 a−1 (14–16% and of annual NEE 176–276 gC m−2 a−1. The inter-site standard deviation was higher for GPP and Re, 534 gC m−2 a−1 (37

  9. Impact of cloudiness on net ecosystem exchange of carbon dioxide in different types of forest ecosystems in China

    Directory of Open Access Journals (Sweden)

    M. Zhang

    2010-02-01

    Full Text Available Clouds can significantly affect carbon exchange process between forest ecosystems and the atmosphere by influencing the quantity and quality of solar radiation received by ecosystem's surface and other environmental factors. In this study, we analyzed the effects of cloudiness on net ecosystem exchange of carbon dioxide (NEE in a temperate broad-leaved Korean pine mixed forest at Changbaishan (CBS and a subtropical evergreen broad-leaved forest at Dinghushan (DHS, based on the flux data obtained during June–August from 2003 to 2006. The results showed that the response of NEE of forest ecosystems to photosynthetically active radiation (PAR differed under clear skies and cloudy skies. Compared with clear skies, the light-saturated maximum photosynthetic rate (Pec,max at CBS under cloudy skies during mid-growing season (from June to August increased by 34%, 25%, 4% and 11% in 2003, 2004, 2005 and 2006, respectively. In contrast, Pec,max of the forest ecosystem at DHS was higher under clear skies than under cloudy skies from 2004 to 2006. When the clearness index (kt ranged between 0.4 and 0.6, the NEE reached its maximum at both CBS and DHS. However, the NEE decreased more dramatically at CBS than at DHS when kt exceeded 0.6. The results indicate that cloudy sky conditions are beneficial to net carbon uptake in the temperate forest ecosystem and the subtropical forest ecosystem. Under clear skies, vapor pressure deficit (VPD and air temperature increased due to strong light. These environmental conditions led to greater decrease in gross ecosystem photosynthesis (GEP and greater increase in ecosystem respiration (Re at CBS than at DHS. As a result, clear sky conditions caused more reduction of NEE in the temperate forest ecosystem than in the subtropical forest ecosystem. The response of NEE of different forest ecosystems to the changes in

  10. Sensitivity of the boreal forest-mire ecotone CO2, CH4, and N2O global warming potential to rainy and dry weather

    Science.gov (United States)

    Ťupek, Boris; Minkkinen, Kari; Vesala, Timo; Nikinmaa, Eero

    2015-04-01

    In a mosaic of well drained forests and poorly drained mires of boreal landscape the weather events such as drought and rainy control greenhouse gas dynamics and ecosystem global warming potential (GWP). In forest-mire ecotone especially in ecosystems where CO2 sink is nearly balanced with CO2 source, it's fairly unknown whether the net warming effect of emissions of gases with strong radiative forcing (CH4 and N2O) could offset the net cooling effect of CO2 sequestration. We compared the net ecosystem CO2 exchange (NEE) estimated from the carbon sequestrations of forest stands and forest floor CO2 fluxes against CH4 and N2O fluxes of nine forest/mire site types along the soil moisture gradient in Finland. The ground water of nine sites changed between 10 m in upland forests and 0.1 m in mires, and weather during three years ranged between exceptionally wet and dry for the local climate. The NEE of upland forests was typically a sink of CO2, regardless the weather. Though, xeric pine forest was estimated to be a source of CO2 during wet and intermediate year and became a weak sink only in dry year. The NEE of forest-mire transitions ranged between a sink in dry year, while increased stand carbon sequestration could offset the reduced forest floor CO2 emission, and a source in wet year. The NEE of two sparsely forested mires strongly differed. The lawn type mire was balanced around zero and the hummock type mire was relatively strong NEE sink, regardless the weather. Generally, nearly zero N2O emission could not offset the cooling effect of net CH4 sink and net CO2 sink of upland forest and forest-mire transitions. However in sparsely forested mires, with N2O emission also nearly zero, the CH4 emission during wet and intermediate year played important role in turning the net cooling effect of NEE into a net warming. When evaluating GWP of boreal landscapes, undisturbed forest-mire transitions should be regarded as net cooling ecosystems instead of hotspots of net

  11. Arctic ecosystem responses to changes in water table and surface warming

    Science.gov (United States)

    Olivas, P. C.; Oberbauer, S. F.; Tweedie, C. E.; Oechel, W. C.

    2009-12-01

    Although low in productivity, arctic ecosystems store close to 20% of the global soil carbon as a result of low decomposition rates enhanced by high soil moisture availability and low temperatures. Expected global climatic changes are likely to significantly increase the temperature in the Arctic, disturbing surface soil moisture patterns and potentially increasing turnover of soil organic matter, thus reversing the role of the Arctic as a carbon sink. Our goal was to determine the short-term ecosystem CO2 exchange response to drying, flooding, and warming, and understand the potential effects that climatic changes could have on the long-term carbon balance of the Arctic. We carried out this study during the growing seasons from 2006 to 2008 on the coastal plain near Barrow, Alaska. We used a 62 ha thawed lake, divided into three sections: drained, flooded and intermediate treatments. Temperature treated plots were replicated within each water treatment category using open top chambers. We assessed ecosystem responses to water and temperature treatments as: ecosystem respiration (ER), gross primary photosynthesis (GPP) and net ecosystem balance (NEE) using chamber-based measurements. We found a strong CO2 exchange response to changes in water table and surface temperature. However, the magnitude of the response differed among carbon flux components. Although flooding increased NEE, the increase was more a result of a decrease in ER rather than an increase in GPP. High water tables can also reduce GPP by submerging leaf area, especially that of mosses. Drying increased ER and GPP, however, species composition and microtopography position affected the magnitude of the changes ultimately affecting NEE. Areas dominated by mosses experienced a reduction of sink capacity, whereas areas dominated by vascular plants experienced an increase in NEE regardless of the drying of the moss layer. Warming affected all CO2 flux components. GPP increased in all treatments except in

  12. Anther and pollen development in some species of Poaceae (Poales Desenvolvimento da antera e do grão de pólen em espécies de Poaceae (Poales

    Directory of Open Access Journals (Sweden)

    AT. Nakamura

    2010-05-01

    Full Text Available Anther and pollen development were studied in Olyra humilis Nees, Sucrea monophylla Soderstr, (Bambusoideae, Axonopus aureus P. Beauv., Paspalum polyphyllum Nees ex Trin. (Panicoideae, Eragrostis solida Nees, and Chloris elata Desv. (Chloridoideae. The objective of this study was to characterise, embryologically, these species of subfamilies which are considered basal, intermediate and derivate, respectively. The species are similar to each other and to other Poaceae. They present the following characters: tetrasporangiate anthers; monocotyledonous-type anther wall development, endothecium showing annular thickenings, secretory tapetum; successive microsporogenesis; isobilateral tetrads; spheroidal, tricellular, monoporate pollen grains with annulus and operculum. Nevertheless, the exine patterns of the species studied are distinct. Olyra humilis and Sucrea monophylla (Bambusoideae show a granulose pattern, whereas in the other species, it is insular. In addition, Axonopus aureus and Paspalum polyphyllum (Panicoideae have a compactly insular spinule pattern, while Chloris elata and Eragrostis solida (Chloridoideae show a sparsely insular spinule pattern. The exine ornamentation may be considered an important feature at the infrafamiliar level.O desenvolvimento da antera e do grão de pólen de Olyra humilis Nees, Sucrea monophylla Soderstr. (Bambusoideae, Axonopus aureus P. Beauv., Paspalum polyphyllum Nees ex Trin. (Panicoideae, Eragrostis solida Nees and Chloris elata Desv. (Chloridoideae foi estudado visando caracterizar embriologicamente essas espécies de subfamílias consideradas basal, intermediária e derivada, respectivamente. As espécies são similares entre si e entre as demais Poaceae. Apresentam os seguintes caracteres: anteras tetrasporangiadas; desenvolvimento da parede da antera do tipo monocotiledôneo, endotécio com espessamento de parede anelar, tapete secretor; microsporogênese sucessiva; tétrades isobilaterais; grãos de

  13. Ecohydrological and Biophysical Controls on Carbon Cycling in Two Seasonally Snow-covered Forests

    Science.gov (United States)

    Chan, A. M.; Brooks, P. D.; Burns, S. P.; Litvak, M. E.; Blanken, P.; Bowling, D. R.

    2014-12-01

    In many seasonally snow-covered forests, the snowpack is the primary water resource. The snowpack also serves as an insulating layer over the soil, warming soil throughout the winter and preserving moisture conditions from the preceding fall. Therefore, the total amount of water in the snowpack as well as the timing and duration of the snow-covered season are likely to have a strong influence on forest productivity through the regulation of the biophysical environment. We investigated how interannual variation in the amount and timing of seasonal snow cover affect winter carbon efflux and growing season carbon uptake at the Niwot Ridge AmeriFlux site (NWT) in Colorado (3050m a.s.l.; 40˚N) and the Valles Caldera Mixed-Conifer AmeriFlux site (VC) in New Mexico (3003m a.s.l.; 36˚N). The tree species composition at NWT is dominated by Abies lasiocarpa, Picea engelmannii, and Pinus contorta. At VC, the dominant tree species are Pseudotsuga menziesii, Abies concolor, Picea pungens, Pinus strobiformis, Pinus flexilis, Pinus ponderosa, and Populus tremuloides. We used net ecosystem exchange (NEE) and climate data from 1999-2012 at NWT and 2007-2012 at VC to divide each year into the growing season, when NEE is negative, and the winter, when NEE is positive. Snow water equivalent (SWE), precipitation, and duration of snow cover data were obtained from USDA/NRCS SNOTEL sites near each forest. At both sites, the start of the growing season was strongly controlled by air temperature, but growing season NEE was not dependent on the length of the growing season. At NWT, total winter carbon efflux was strongly influenced by both the amount and duration of the snowpack, measured as SWE integrated over time. Years with higher integrated SWE had higher winter carbon efflux and also had warmer soil under the snowpack. These patterns were not seen at VC. However, peak SWE amount was positively correlated with growing season NEE at VC, but not at NWT. These results suggest that

  14. Weed-cover versus weed-removal management in olive orchards: influence on the carbon balance at the ecosystem scale

    Science.gov (United States)

    Chamizo, Sonia; Serrano-Ortiz, Penélope; Vicente-Vicente, José Luis; Sánchez-Cañete, Enrique P.; López-Ballesteros, Ana; Kowalski, Andrew S.

    2016-04-01

    Agriculture plays an important role in the C budget at the global scale. Traditional practices based on soil tillage and applying herbicides to remove weeds have caused damage to soils and led to important losses of soil organic C and increased CO2 emissions to the atmosphere. Changing trends from traditional agriculture to conservation agriculture practices may have an important role in both C and water budgets and the transformation of agriculture from C source to C sink. The objective of this study was to analyse the effect of two treatments, weed removal by herbicides versus weed cover conservation, on the C balance in an irrigated olive orchard in SE Spain. Measurements of CO2 exchange were made from October 2014 to September 2015 using two eddy covariance towers, one for each olive crop treatment. Results show that CO2 fluxes at the ecosystem scale were similar in the two treatments during initial conditions, prior to weed growth in the soils without herbicide application (October). During the first week, daily net ecosystem exchange (NEE) was close to zero in both treatments, with values ranging from 1.06 to -0.41 g C m-2 in the weed cover treatment, and from 0.76 to -0.69 g C m-2 in the weed removal treatment. As weed growth increased, higher net CO2 assimilation was found in the treatment with weed cover. In both treatments, maximum net CO2 assimilation was found in March, with a monthly NEE of -72 and -28 g C m-2 in the treatment with and without weed cover, respectively. In May, after the weeds were cut and left on the soil, a strong increase was observed in NEE in the treatment with weed cover due to decreased CO2 assimilation and increased respiration compared to the treatment without weed cover. Therefore, soil chamber measurements showed average respiration rates of 2.57 and 1.57 μmol m-2 s-2 in the weed cover and weed removal treatment, respectively. Finally, the highest monthly NEE was registered during July, with both treatments showing a similar

  15. Reduced uncertainty of regional scale CLM predictions of net carbon fluxes and leaf area indices with estimated plant-specific parameters

    Science.gov (United States)

    Post, Hanna; Hendricks Franssen, Harrie-Jan; Han, Xujun; Baatz, Roland; Montzka, Carsten; Schmidt, Marius; Vereecken, Harry

    2016-04-01

    Reliable estimates of carbon fluxes and states at regional scales are required to reduce uncertainties in regional carbon balance estimates and to support decision making in environmental politics. In this work the Community Land Model version 4.5 (CLM4.5-BGC) was applied at a high spatial resolution (1 km2) for the Rur catchment in western Germany. In order to improve the model-data consistency of net ecosystem exchange (NEE) and leaf area index (LAI) for this study area, five plant functional type (PFT)-specific CLM4.5-BGC parameters were estimated with time series of half-hourly NEE data for one year in 2011/2012, using the DiffeRential Evolution Adaptive Metropolis (DREAM) algorithm, a Markov Chain Monte Carlo (MCMC) approach. The parameters were estimated separately for four different plant functional types (needleleaf evergreen temperate tree, broadleaf deciduous temperate tree, C3-grass and C3-crop) at four different sites. The four sites are located inside or close to the Rur catchment. We evaluated modeled NEE for one year in 2012/2013 with NEE measured at seven eddy covariance sites in the catchment, including the four parameter estimation sites. Modeled LAI was evaluated by means of LAI derived from remotely sensed RapidEye images of about 18 days in 2011/2012. Performance indices were based on a comparison between measurements and (i) a reference run with CLM default parameters, and (ii) a 60 instance CLM ensemble with parameters sampled from the DREAM posterior probability density functions (pdfs). The difference between the observed and simulated NEE sum reduced 23% if estimated parameters instead of default parameters were used as input. The mean absolute difference between modeled and measured LAI was reduced by 59% on average. Simulated LAI was not only improved in terms of the absolute value but in some cases also in terms of the timing (beginning of vegetation onset), which was directly related to a substantial improvement of the NEE estimates in

  16. Propuesta para la enseñanza de Ciencias Naturales en Educación Primaria en un aula inclusiva

    Directory of Open Access Journals (Sweden)

    Ileana María Greca

    2017-01-01

    Full Text Available Este trabajo presenta una propuesta didáctica en Ciencias Naturales, basada en la metodología de la indagación, para un aula inclusiva. La propu esta, diseñada con las adaptaciones correspondientes para atender cada caso especial, fue implementada en una clase de tercero de primaria con 26 niños, 5 de ellos con necesidades educativas especiales (NEE. Los resultados muestran la viabilidad y benefic ios para todos del uso de la indagación: todos los niños, incluyendo aquellos con NEE superaron los objetivos planteados, estableciéndose un alto grado de motivación y compromiso, aunque surgieron dificultades relacionadas con la dinámica del trabajo grupal.

  17. Optimizing Photosynthetic and Respiratory Parameters Based on the Seasonal Variation Pattern in Regional Net Ecosystem Productivity Obtained from Atmospheric Inversion

    Science.gov (United States)

    Chen, Z.; Chen, J.; Zheng, X.; Jiang, F.; Zhang, S.; Ju, W.; Yuan, W.; Mo, G.

    2014-12-01

    In this study, we explore the feasibility of optimizing ecosystem photosynthetic and respiratory parameters from the seasonal variation pattern of the net carbon flux. An optimization scheme is proposed to estimate two key parameters (Vcmax and Q10) by exploiting the seasonal variation in the net ecosystem carbon flux retrieved by an atmospheric inversion system. This scheme is implemented to estimate Vcmax and Q10 of the Boreal Ecosystem Productivity Simulator (BEPS) to improve its NEP simulation in the Boreal North America (BNA) region. Simultaneously, in-situ NEE observations at six eddy covariance sites are used to evaluate the NEE simulations. The results show that the performance of the optimized BEPS is superior to that of the BEPS with the default parameter values. These results have the implication on using atmospheric CO2 data for optimizing ecosystem parameters through atmospheric inversion or data assimilation techniques.

  18. MATERIALS FOR A REVISION OF LAURACEAE IV*

    Directory of Open Access Journals (Sweden)

    a. j. g. h. kostermans

    1974-12-01

    Full Text Available In the genus Actinodaphtie Nees one new combination and one newspecies ace presented; in LAndera Thunb. one new combination, 4 newspecies and one new forma; in lAtsea Lam. one species has been reducedto synonymy, one nomen novum is presented, 5 new species are describedand of 6 species new cecords are given; one species has been reinstated.The obscure Mackilus sericea Bl. is a3sumed to be conspecific withPersea bombyeina (King ex Hook, f. Kosterm. In the genus Persea Mill.one nomen novnm, two new combinations and one new species are createdand proposed. In the genus Phoebe Nees one new combination and two new species are presented

  19. La influencia de la convivencia escolar en el nivel de inclusión educativa, en estudiantes de bachiller

    Directory of Open Access Journals (Sweden)

    MSc. Rolando Medina Peña

    2016-04-01

    Full Text Available La inclusión educativa muchas veces no es bien entendida y se interpreta de diversas formas en el mundo. Desde el campo educativo se connota, a la manera en que la ins­titución educacional da respuesta a la diversidad y, tiene relación directa con el término necesidades educativas es­peciales (NEE. La investigación examina la influencia del código de convivencia escolar en el nivel de inclusión edu­cativa, a partir de la asunción de las necesidades educati­vas especiales de algunos de sus estudiantes. Se perfec­ciona la comprensión de las NEE, de inclusión educativa y los recursos educativos que se ajustan a las peculiaridades del desarrollo humano.

  20. Analytical studies on the LAOS behaviors of some popularly used viscoelastic constitutive equations with a new insight on stress decomposition of normal stresses

    Science.gov (United States)

    Bae, Jung-Eun; Cho, Kwang Soo

    2017-09-01

    Shear stress of Large Amplitude Oscillatory Shear (LAOS) is known to be decomposed to elastic and viscous stresses. According to the parity of normal stress with respect to shear strain and shear rate, it also can be mathematically decomposed into two parts: NEE (even symmetry part for both strain and strain rate) and NOO (odd symmetry part for both shear strain and shear rate). However, the physical meaning of the decomposed normal stress is questionable. This paper is to prove the conjecture that NEE is elastic and NOO is viscous under the condition of time-strain separability. For the purpose of the proof, we developed mathematical tools for the analytical solutions of LAOS. We applied the mathematical methods to some popularly used constitutive equations such as the convected Maxwell models, the separable Kaye-Bernstein-Kearsley-Zepas (K-BKZ) model, the Giesekus model, and the Phan-Thien and Tanner model.

  1. Effect of selected antiasthmatic plant constituents against micro organism causing upper respiratory tract infection.

    Science.gov (United States)

    Nilani, P; Duraisamy, B; Dhamodaran, P; Ravichandran, S; Elango, K

    2010-01-01

    Most exacerbations of asthma can be proven to be associated with bacterial infections and there is scientific evidence that frequent respiratory infections particularly bacterial infections provoke asthma attack. Considering these facts different plant extracts and phytoconstituents with proven anti asthmatic property had been selected for screening anti microbial activity in in-vitro models. In the present study, Coleus forskohlii Willd. extract (10% Forskolin), Piper Longum L. Extract (20% Piperine), Adathoda vasica Nees. extract (30% Vasicinone), Curcuma longa L. extract (60% Curcumin) were screened for the antibacterial activity against human pathogens causing upper respiratory infection namely Haemophilus influenzae , Streptococcus pneumoniae , Streptococcus pyrogene and Staphylococcus aureus, by taking Gentamycin, Optochin, Bacitracin and Amoxicillin as reference standards. Except for Adathoda vasica Nees. extract, all the other selected plant extracts exhibited a moderate activity antibacterial activity against selected strains.

  2. The Survival of the Fattest. Evolution of needs, lust and social value in a long-run perspective

    OpenAIRE

    Hanappi, Hardy

    2004-01-01

    As recent data on average weight of human individuals in OECD countries vividly documents the primary metabolism of human individuals, e.g. physical reproduction, already produces deteriorating results. The concept of needs in the sense of desires for primary reproduction necessities has to be re-conceptualized. What has been substituted for the power of needs was the desire for lust: Consumers are offered objects for which they subjectively should develop a substitute of an objective nee...

  3. Statistical properties of proportional residual energy intake as a new measure of energetic efficiency.

    Science.gov (United States)

    Zamani, Pouya

    2017-08-01

    Traditional ratio measures of efficiency, including feed conversion ratio (FCR), gross milk efficiency (GME), gross energy efficiency (GEE) and net energy efficiency (NEE) may have some statistical problems including high correlations with milk yield. Residual energy intake (REI) or residual feed intake (RFI) is another criterion, proposed to overcome the problems attributed to the traditional ratio criteria, but it does not account for production or intake levels. For example, the same REI value could be considerable for low producing and negligible for high producing cows. The aim of this study was to propose a new measure of efficiency to overcome the problems attributed to the previous criteria. A total of 1478 monthly records of 268 lactating Holstein cows were used for this study. In addition to FCR, GME, GEE, NEE and REI, a new criterion called proportional residual energy intake (PREI) was calculated as REI to net energy intake ratio and defined as proportion of net energy intake lost as REI. The PREI had an average of -0·02 and range of -0·36 to 0·27, meaning that the least efficient cow lost 0·27 of her net energy intake as REI, while the most efficient animal saved 0·36 of her net energy intake as less REI. Traditional ratio criteria (FCR, GME, GEE and NEE) had high correlations with milk and fat corrected milk yields (absolute values from 0·469 to 0·816), while the REI and PREI had low correlations (0·000 to 0·069) with milk production. The results showed that the traditional ratio criteria (FCR, GME, GEE and NEE) are highly influenced by production traits, while the REI and PREI are independent of production level. Moreover, the PREI adjusts the REI magnitude for intake level. It seems that the PREI could be considered as a worthwhile measure of efficiency for future studies.

  4. Force-free electromagnetic pulses in a laboratory plasma

    Science.gov (United States)

    Stenzel, R. L.; Urrutia, J. M.

    1990-01-01

    A short, intense current pulse is drawn from an electrode immersed in a magnetized afterglow plasma. The induced magnetic field B(r,t) assumes the shape of a helical double vortex which propagates along B(0) through the uniform plasma as a whistler mode. The observations support a prediction of force-free (J x B + neE = 0) electromagnetic fields and solitary waves. Energy and helicity are approximately conserved.

  5. Intra-seasonal mapping of CO2 flux in rangelands of northern Kazakhstan at one-kilometer resolution

    Science.gov (United States)

    Wylie, B.K.; Gilmanov, T.G.; Johnson, D.A.; Saliendra, Nicanor Z.; Akshalov, K.; Tieszen, L.L.; Reed, B.C.; Laca, Emilio

    2004-01-01

    Algorithms that establish relationships between variables obtained through remote sensing and geographic information system (GIS) technologies are needed to allow the scaling up of site-specific CO2 flux measurements to regional levels. We obtained Bowen ratio-energy balance (BREB) flux tower measurements during the growing seasons of 1998-2000 above a grassland steppe in Kazakhstan. These BREB data were analyzed using ecosystem light-curve equations to quantify 10-day CO2 fluxes associated with gross primary production (GPP) and total respiration (R). Remotely sensed, temporally smoothed normalized difference vegetation index (NDVIsm) and environmental variables were used to develop multiple regression models for the mapping of 10-day CO2 fluxes for the Kazakh steppe. Ten-day GPP was estimated (R 2 = 0.72) by day of year (DOY) and NDVIsm, and 10-day R was estimated (R2 = 0.48) with the estimated GPP and estimated 10-day photosynthetically active radiation (PAR). Regression tree analysis estimated 10-day PAR from latitude, NDVIsm, DOY, and precipitation (R2 = 0.81). Fivefold cross-validation indicated that these algorithms were reasonably robust. GPP, R, and resulting net ecosystem exchange (NEE) were mapped for the Kazakh steppe grassland every 10 days and summed to produce regional growing season estimates of GPP, R, and NEE. Estimates of 10-day NEE agreed well with BREB observations in 2000, showing a slight underestimation in the late summer. Growing season (May to October) mean NEE for Kazakh steppe grasslands was 1.27 Mg C/ha in 2000. Winter flux data were collected during the winter of 2001-2002 and are being analyzed to close the annual carbon budget for the Kazakh steppe. ?? 2004 Springer-Verlag New York, LLC.

  6. Rain events decrease boreal peatland net CO2 uptake through reduced light availability.

    Science.gov (United States)

    Nijp, Jelmer J; Limpens, Juul; Metselaar, Klaas; Peichl, Matthias; Nilsson, Mats B; van der Zee, Sjoerd E A T M; Berendse, Frank

    2015-06-01

    Boreal peatlands store large amounts of carbon, reflecting their important role in the global carbon cycle. The short-term exchange and the long-term storage of atmospheric carbon dioxide (CO2 ) in these ecosystems are closely associated with the permanently wet surface conditions and are susceptible to drought. Especially, the single most important peat forming plant genus, Sphagnum, depends heavily on surface wetness for its primary production. Changes in rainfall patterns are expected to affect surface wetness, but how this transient rewetting affects net ecosystem exchange of CO2 (NEE) remains unknown. This study explores how the timing and characteristics of rain events during photosynthetic active periods, that is daytime, affect peatland NEE and whether rain event associated changes in environmental conditions modify this response (e.g. water table, radiation, vapour pressure deficit, temperature). We analysed an 11-year time series of half-hourly eddy covariance and meteorological measurements from Degerö Stormyr, a boreal peatland in northern Sweden. Our results show that daytime rain events systematically decreased the sink strength of peatlands for atmospheric CO2 . The decrease was best explained by rain associated reduction in light, rather than by rain characteristics or drought length. An average daytime growing season rain event reduced net ecosystem CO2 uptake by 0.23-0.54 gC m(-2) . On an annual basis, this reduction of net CO2 uptake corresponds to 24% of the annual net CO2 uptake (NEE) of the study site, equivalent to a 4.4% reduction of gross primary production (GPP) during the growing season. We conclude that reduced light availability associated with rain events is more important in explaining the NEE response to rain events than rain characteristics and changes in water availability. This suggests that peatland CO2 uptake is highly sensitive to changes in cloud cover formation and to altered rainfall regimes, a process hitherto largely

  7. Statistical uncertainty of eddy flux-based estimates of gross ecosystem carbon exchange at Howland Forest, Maine

    Science.gov (United States)

    Hagen, S. C.; Braswell, B. H.; Linder, E.; Frolking, S.; Richardson, A. D.; Hollinger, D. Y.

    2006-04-01

    We present an uncertainty analysis of gross ecosystem carbon exchange (GEE) estimates derived from 7 years of continuous eddy covariance measurements of forest-atmosphere CO2 fluxes at Howland Forest, Maine, USA. These data, which have high temporal resolution, can be used to validate process modeling analyses, remote sensing assessments, and field surveys. However, separation of tower-based net ecosystem exchange (NEE) into its components (respiration losses and photosynthetic uptake) requires at least one application of a model, which is usually a regression model fitted to nighttime data and extrapolated for all daytime intervals. In addition, the existence of a significant amount of missing data in eddy flux time series requires a model for daytime NEE as well. Statistical approaches for analytically specifying prediction intervals associated with a regression require, among other things, constant variance of the data, normally distributed residuals, and linearizable regression models. Because the NEE data do not conform to these criteria, we used a Monte Carlo approach (bootstrapping) to quantify the statistical uncertainty of GEE estimates and present this uncertainty in the form of 90% prediction limits. We explore two examples of regression models for modeling respiration and daytime NEE: (1) a simple, physiologically based model from the literature and (2) a nonlinear regression model based on an artificial neural network. We find that uncertainty at the half-hourly timescale is generally on the order of the observations themselves (i.e., ˜100%) but is much less at annual timescales (˜10%). On the other hand, this small absolute uncertainty is commensurate with the interannual variability in estimated GEE. The largest uncertainty is associated with choice of model type, which raises basic questions about the relative roles of models and data.

  8. Page 1 The Fungicide Kitazin and the Mycoflora of Rice 301 TABLE ...

    Indian Academy of Sciences (India)

    D. halodes (Drechs.) Subram. 'É. and Jain * 曦... 1 1 施○ 影编| 1 1. D. hawaiiensis (Bugnicourt). Subram. and Jain ... 3 . . 磁蟾1 1. 噬命○ 岭1. Alternaria tenuis Nees ... 2 * * ○ ○ 1 2 2 . . 1. Humicola fusco-atra Traaen 4 2 3 ... 1 3 1. 2 2. Sepedonium chrysospermum. (Bulliard) Fries .. * * * * 学瓷歌够1. Trichoderma viride Pers.

  9. Nuevos registros del género Cissampelos (Menispermaceae para la flora Argentina

    Directory of Open Access Journals (Sweden)

    María Peña-Chocarro

    2015-01-01

    Full Text Available Cissampelos andromorpha DC. y C. arenicolaM. Nee & R. Ortiz se citan por primera vez para la flora Argentina. Se presentan descripciones e imágenes de pliegos de herbario de las especies mencionadas y se actualizan sus distribuciones geográficas. Se incluye una clave para la identificación de las cuatro especies de Cissampelospresentes en Argentina

  10. Estimation of Community Land Model parameters for an improved assessment of net carbon fluxes at European sites

    Science.gov (United States)

    Post, Hanna; Vrugt, Jasper A.; Fox, Andrew; Vereecken, Harry; Hendricks Franssen, Harrie-Jan

    2017-03-01

    The Community Land Model (CLM) contains many parameters whose values are uncertain and thus require careful estimation for model application at individual sites. Here we used Bayesian inference with the DiffeRential Evolution Adaptive Metropolis (DREAM(zs)) algorithm to estimate eight CLM v.4.5 ecosystem parameters using 1 year records of half-hourly net ecosystem CO2 exchange (NEE) observations of four central European sites with different plant functional types (PFTs). The posterior CLM parameter distributions of each site were estimated per individual season and on a yearly basis. These estimates were then evaluated using NEE data from an independent evaluation period and data from "nearby" FLUXNET sites at 600 km distance to the original sites. Latent variables (multipliers) were used to treat explicitly uncertainty in the initial carbon-nitrogen pools. The posterior parameter estimates were superior to their default values in their ability to track and explain the measured NEE data of each site. The seasonal parameter values reduced with more than 50% (averaged over all sites) the bias in the simulated NEE values. The most consistent performance of CLM during the evaluation period was found for the posterior parameter values of the forest PFTs, and contrary to the C3-grass and C3-crop sites, the latent variables of the initial pools further enhanced the quality-of-fit. The carbon sink function of the forest PFTs significantly increased with the posterior parameter estimates. We thus conclude that land surface model predictions of carbon stocks and fluxes require careful consideration of uncertain ecological parameters and initial states.

  11. Direct and indirect effects of climatic variations on the interannual variability in net ecosystem exchange across terrestrial ecosystems

    Directory of Open Access Journals (Sweden)

    Junjiong Shao

    2016-08-01

    Full Text Available Climatic variables not only directly affect the interannual variability (IAV in net ecosystem exchange of CO2 (NEE but also indirectly drive it by changing the physiological parameters. Identifying these direct and indirect paths can reveal the underlying mechanisms of carbon (C dynamics. In this study, we applied a path analysis using flux data from 65 sites to quantify the direct and indirect climatic effects on IAV in NEE and to evaluate the potential relationships among the climatic variables and physiological parameters that represent physiology and phenology of ecosystems. We found that the maximum photosynthetic rate was the most important factor for the IAV in gross primary productivity (GPP, which was mainly induced by the variation in vapour pressure deficit. For ecosystem respiration (RE, the most important drivers were GPP and the reference respiratory rate. The biome type regulated the direct and indirect paths, with distinctive differences between forests and non-forests, evergreen needleleaf forests and deciduous broadleaf forests, and between grasslands and croplands. Different paths were also found among wet, moist and dry ecosystems. However, the climatic variables can only partly explain the IAV in physiological parameters, suggesting that the latter may also result from other biotic and disturbance factors. In addition, the climatic variables related to NEE were not necessarily the same as those related to GPP and RE, indicating the emerging difficulty encountered when studying the IAV in NEE. Overall, our results highlight the contribution of certain physiological parameters to the IAV in C fluxes and the importance of biome type and multi-year water conditions, which should receive more attention in future experimental and modelling research.

  12. The Role of Walkers? Needs and Expectations in Supporting Maintenance of Attendance at Walking Groups: A Longitudinal Multi-Perspective Study of Walkers and Walk Group Leaders

    OpenAIRE

    Aikaterini Kassavou; Andrew Turner; French, David P.

    2015-01-01

    Background There is good evidence that when people?s needs and expectations regarding behaviour change are met, they are satisfied with that change, and maintain those changes. Despite this, there is a dearth of research on needs and expectations of walkers when initially attending walking groups and whether and how these needs and expectations have been satisfied after a period of attendance. Equally, there is an absence of research on how people who lead these groups understand walkers? nee...

  13. A synopsis of Peristrophe (Acanthaceae in southern Africa

    Directory of Open Access Journals (Sweden)

    K. Balkwill

    1996-10-01

    Full Text Available A synopsis of Peristrophe Nees (Acanthaceae in southern Africa is provided. Peristrophe comprises nine species, one with two subspecies in southern Africa. A key for identification and descriptions of species not included in recent literature are provided. Morphology of tertiary bracts,indumentum on stems and distribution is illustrated and diagnostic characters, distribution, habitat, flowering  time and conservation status are discussed for each species.

  14. Kampen om kompetencerne

    DEFF Research Database (Denmark)

    Pedersen, Kim; Pedersen, Steen Høyrup

    2003-01-01

    As society has changed from an industrial society to a knowledge society, the concept of qualifications has been replaced by concepts of competence and competence development in a life-long learning perspectivel. The starting point of this article is that behind this apparent consensus on the nee...... for competence, disagreement between different interests and perspectives lies hidden. The articles discusses how real competence can be measured and evaluated....

  15. Comparing the Net Ecosystem Exchange of Two Cropping Systems for Dairy Feed Production

    Science.gov (United States)

    Sulaiman, M. F.; Wagner-Riddle, C.; Brown, S. E.

    2015-12-01

    A three-year study was conducted from 2012 to 2014 to determine the net CO2 fluxes from corn and hay, the two main feed crops used in dairy production. The aim of this study is to better understand the net ecosystem exchange (NEE) in annual and perennial cropping systems used in dairy production to benefit greenhouse gas emission model developments and the life cycle analysis of dairy production. The study was conducted on two 4-ha plots where one plot was a 5-year old hayfield and the other plot was planted in a continuous cycle corn. All plots were continuously monitored using the flux-gradient method deployed with a tunable diode laser trace gas analyzer and sonic anemometers. All plots received dairy manure as fertilizer applied according to common practice. The cumulative NEE for the three years of the study was -873.15 g C m-2 for corn and -409.36 g C m-2 for hay. Differences in respiration between the two cropping systems was found to be the larger factor compared to differences in gross ecosystem production (GEP) that resulted in the contrasting cumulative NEE where cumulative respiration for the three years for hay was 3094.23 g C m-2 as opposed to 2078.11 g C m-2 for corn. Cumulative GEP for the three years was 3503.60 and 2951.31 g C m-2 for hay and corn respectively. Inter-annual and inter-crop variability of the NEE, GEP and respiration will be discussed in relation to biomass production, climatic conditions and crop physiological characteristics.

  16. The effects of docks on seagrasses, with particular emphasis on the threatened seagrass, Halophila johnsonii

    OpenAIRE

    Landry, J. Brooke; Kenworthy, W. Judson; Di Carlo, Giuseppe

    2008-01-01

    In March of 2005, the National Oceanic and Atmospheric Administration's Special Projects Office released "Population Trends along the Coastal United States: 1980-2008." This report includes population changes and trends between 1980 and 2003 and projected changes in coastal populations by 2008. Given the findings, pressure on coastal resources around the country will continue to rise, particularly in Florida. ... One of our most valuable coastal resources is seagrass, but human desire and nee...

  17. THE NEW WORLD SPECIES OF CINNAMOMUM TREW (LAURACEAE

    Directory of Open Access Journals (Sweden)

    AJGH Kostermans

    2014-01-01

    Full Text Available The American species of Phoebe Nees are relegated to Cinnamomum Trew; the reasons for this transfer are discussed. To retain nomenclatural stability the new combinations which have become necessary are presented, in anticipation of a general revision of  the   genus   Cinnamomum;   68   new   combinations   and   names   are presented.

  18. Final Environmental Assessment for the Military Housing Privatization Initiative (MHPI), Dyess Air Force Base, Texas

    Science.gov (United States)

    2011-07-01

    area. Nearby communities include the cities of Albany, 35 miles to the northwest; Brownwood, 78 miles southeast; San Angelo, 89 miles southwest...and remo e the ball park infrastructure at th 14-acre ball park area. nee demolition i completed to the satisfaction of the Government, the developer...le ed for a period of four ears, and the de eloper would then demoli h the xisting parking Jot and remo e the ball park infrastructure at the 14-acre

  19. A regional high-resolution carbon flux inversion of North America for 2004

    OpenAIRE

    Schuh, A. E.; A. S. Denning; Corbin, K. D.; Baker, I. T.; M. Uliasz; N. Parazoo; A. E. Andrews; D. E. J. Worthy

    2010-01-01

    Resolving the discrepancies between NEE estimates based upon (1) ground studies and (2) atmospheric inversion results, demands increasingly sophisticated techniques. In this paper we present a high-resolution inversion based upon a regional meteorology model (RAMS) and an underlying biosphere (SiB3) model, both running on an identical 40 km grid over most of North America. Current operational systems like CarbonTracker as well as many previous glob...

  20. Data Mining and its Application in Banking Industry: A Survey

    OpenAIRE

    Mohammad Behrouzian Nejad; Ebrahim Behrouzian Nejad; Mehdi Sadeghzadeh

    2011-01-01

    Human progress in recent decades in the field of collecting and storing data and results, has led to dramatically increase the size of the database. Importantly, this large database, information and knowledge that can be extracted from them, to do this, the use of intelligent and structured approach is needed. Data Mining, a new scientific field of information retrieval is the database. Data Mining can extract the information in the database and data related to critical business knowledge nee...

  1. Factors influencing users' attitude towards display advertising on Facebook

    OpenAIRE

    Halalau, Ruxandra; Kornias, Gustaf

    2012-01-01

    Background: Researchers have investigated display advertising in the past several years from different perspectives but only in connection to traditional Web sites and not specifically for social networking sites. Facebook is the most prominent social networking site in terms of number of users and its main source of revenue is its online advertising business. Having display advertising in their virtual space is the reason why social networks are able to offer free service and as such the nee...

  2. [Simulation of water and carbon fluxes in harvard forest area based on data assimilation method].

    Science.gov (United States)

    Zhang, Ting-Long; Sun, Rui; Zhang, Rong-Hua; Zhang, Lei

    2013-10-01

    Model simulation and in situ observation are the two most important means in studying the water and carbon cycles of terrestrial ecosystems, but have their own advantages and shortcomings. To combine these two means would help to reflect the dynamic changes of ecosystem water and carbon fluxes more accurately. Data assimilation provides an effective way to integrate the model simulation and in situ observation. Based on the observation data from the Harvard Forest Environmental Monitoring Site (EMS), and by using ensemble Kalman Filter algorithm, this paper assimilated the field measured LAI and remote sensing LAI into the Biome-BGC model to simulate the water and carbon fluxes in Harvard forest area. As compared with the original model simulated without data assimilation, the improved Biome-BGC model with the assimilation of the field measured LAI in 1998, 1999, and 2006 increased the coefficient of determination R2 between model simulation and flux observation for the net ecosystem exchange (NEE) and evapotranspiration by 8.4% and 10.6%, decreased the sum of absolute error (SAE) and root mean square error (RMSE) of NEE by 17.7% and 21.2%, and decreased the SAE and RMSE of the evapotranspiration by 26. 8% and 28.3%, respectively. After assimilated the MODIS LAI products of 2000-2004 into the improved Biome-BGC model, the R2 between simulated and observed results of NEE and evapotranspiration was increased by 7.8% and 4.7%, the SAE and RMSE of NEE were decreased by 21.9% and 26.3%, and the SAE and RMSE of evapotranspiration were decreased by 24.5% and 25.5%, respectively. It was suggested that the simulation accuracy of ecosystem water and carbon fluxes could be effectively improved if the field measured LAI or remote sensing LAI was integrated into the model.

  3. Reconciling estimates of the contemporary North American carbon balance among terrestrial biosphere models, atmospheric inversions, and a new approach for estimating net ecosystem exchange from inventory-based data

    Science.gov (United States)

    Hayes, Daniel J.; Turner, David P.; Stinson, Graham; McGuire, A. David; Wei, Yaxing; West, Tristram O.; Heath, Linda S.; de Jong, Bernardus; McConkey, Brian G.; Birdsey, Richard A.; Kurz, Werner A.; Jacobson, Andrew R.; Huntzinger, Deborah N.; Pan, Yude; Post, W. Mac; Cook, Robert B.

    2012-01-01

    We develop an approach for estimating net ecosystem exchange (NEE) using inventory-based information over North America (NA) for a recent 7-year period (ca. 2000–2006). The approach notably retains information on the spatial distribution of NEE, or the vertical exchange between land and atmosphere of all non-fossil fuel sources and sinks of CO2, while accounting for lateral transfers of forest and crop products as well as their eventual emissions. The total NEE estimate of a -327 ± 252 TgC yr-1 sink for NA was driven primarily by CO2 uptake in the Forest Lands sector (-248 TgC yr-1), largely in the Northwest and Southeast regions of the US, and in the Crop Lands sector (-297 TgC yr-1), predominantly in the Midwest US states. These sinks are counteracted by the carbon source estimated for the Other Lands sector (+218 TgC yr-1), where much of the forest and crop products are assumed to be returned to the atmosphere (through livestock and human consumption). The ecosystems of Mexico are estimated to be a small net source (+18 TgC yr-1) due to land use change between 1993 and 2002. We compare these inventory-based estimates with results from a suite of terrestrial biosphere and atmospheric inversion models, where the mean continental-scale NEE estimate for each ensemble is -511 TgC yr-1 and -931 TgC yr-1, respectively. In the modeling approaches, all sectors, including Other Lands, were generally estimated to be a carbon sink, driven in part by assumed CO2 fertilization and/or lack of consideration of carbon sources from disturbances and product emissions. Additional fluxes not measured by the inventories, although highly uncertain, could add an additional -239 TgC yr-1 to the inventory-based NA sink estimate, thus suggesting some convergence with the modeling approaches.

  4. Classroom Curricular Preparedness For Inclusion Of Pupils With Physical Disability Within Public Inclusive Schools For The Pupils With Physical Disability In Bungoma County Kenya.

    OpenAIRE

    Hesborn Mutoro Chonge; Esther Njeri Kiaritha; James Ololo Otieno

    2015-01-01

    Since the introduction of Special education in Kenya in 1946 numerous special schools have been established. However there has been a move toward integration and later inclusion of students with disabilities in regular schools. Inclusion has its own challenges. Kenya as a rapidly developing country is undergoing drastic social economic and cultural changes. Consequently learners with disabilities in inclusive schools experience a number of challenges. These challenges bring into focus the nee...

  5. [Effect of air temperature and rainfall on wetland ecosystem CO2 exchange in China].

    Science.gov (United States)

    Chu, Xiao-jing; Han, Guang-xuan

    2015-10-01

    Wetland can be a potential efficient sink to reduce global warming due to its higher primary productivity and lower carbon decomposition rate. While there has been a series progress on the influence mechanism of ecosystem CO2 exchange over China' s wetlands, a systematic metaanalysis of data still needs to be improved. We compiled data of ecosystem CO2 exchange of 21 typical wetland vegetation types in China from 29 papers and carried out an integrated analysis of air temperature and precipitation effects on net ecosystem CO2 exchange (NEE), ecosystem respiration (Reco), gross primary productivity (GPP), the response of NEE to PAR, and the response of Reco to temperature. The results showed that there were significant responses (Pair temperature and enhanced precipitation on the annual scale. On the growing season scale, air temperature accounted for 50% of the spatial variation of NEE, 36% of GPP and 19% of Reco, respectively. Both NEE (R2 = 33%) and GPP (R2 =25%) were correlated positively with precipitation (P0.05). Across different Chinese wetlands, both precipitation and temperature had no significant effect on apparent quantum yield (α) or ecosystem respiration in the daytime (Reco,day, P>0.05). The maximum photosynthesis rate (Amax) was remarkably correlated with precipitation (P air temperature. Besides, there was no significant correlation between basal respiration (Rref) and precipitation (P>0.05). Precipitation was negatively correlated with temperature sensitivity of Reco (Q10, P<0.05). Furthermore, temperature accounted for 35% and 46% of the variations in temperature sensitivity of Reco (Q10) and basal respiration (Rref P<0.05), respectively.

  6. Carbon Balance of No-Till Soybean with Winter Wheat Cover Crop in the Southeastern United States

    Science.gov (United States)

    Gebremedhin, M. T.; Loescher, H.; Tsegaye, T.

    2012-12-01

    The southeast is an important agricultural region in the U.S. and key component of the continental carbon budget. Croplands in the region store a substantial amount of soil organic carbon (C). However, their C sink status may be altered under the projected changes in precipitation pattern for the region. The study was conducted at Winfred Thomas Agricultural Research Station, Hazel Green, Alabama (2007-2009). We investigated the seasonal and interannual variation in net ecosystem exchange of CO2 (NEE) of winter wheat (Tricticum aestivum) and soybean (Glycine max) using the eddy covariance method. Annual C balance ranged from the highest source in 2007 (NEE = 100 g C m-2 y-1) to sink (-20 g C m-2 y-1) in 2009. Annual ecosystem respiration (Re) ranged between 750 and 1013 g C m-2 y-1, while gross ecosystem productivity (GEP) was 650-1034 g C m-2 y-1. Seasonal NEE for soybean ranged between 42 and -66 g C m-2. Stronger winter wheat NEE (-80.0, -80.4, -40.0 g C m-2 for 2007, 2008 and 2009) than soybean suggested the importance of winter C uptakes offsetting summer C losses. Re was controlled by air temperature, and it varied between 286 and 542 g C m-2 for soybean, and between 160 and 313 g C m-2 for winter wheat. Precipitation was key determinant of C balance implying larger C release during drought periods. During fallow months, the site was C source. If we include removal of grain off site, this system could become a C source under all conditions.

  7. Antimicrobial activity of Thai traditional medicinal plants extract incorporated alginate-tapioca starch based edible films against food related bacteria including foodborne pathogens

    OpenAIRE

    Tepsorn, Racha

    2009-01-01

    In Thai traditional medicine, different plant extracts are known to have a bactericidal or at least a bacteriostatic effect on bacteria and/or fungi. In Thailand, medicinal plants have been used safely since ancient times as herbal medicines and also as food colouring and flavouring agents. The application of selected plant extracts to foods could prevent foodborne diseases and food spoilage. In this study the antimicrobial activities of Andrographis paniculata (Burm.f.) Nees, Curcuma zedoari...

  8. Initial shifts in nitrogen impact on ecosystem carbon fluxes in an alpine meadow: patterns and causes

    Science.gov (United States)

    Song, Bing; Sun, Jian; Zhou, Qingping; Zong, Ning; Li, Linghao; Niu, Shuli

    2017-09-01

    Increases in nitrogen (N) deposition can greatly stimulate ecosystem net carbon (C) sequestration through positive N-induced effects on plant productivity. However, how net ecosystem CO2 exchange (NEE) and its components respond to different N addition rates remains unclear. Using an N addition gradient experiment (six levels: 0, 2, 4, 8, 16, 32 gN m-2 yr-1) in an alpine meadow on the Qinghai-Tibetan Plateau, we explored the responses of different ecosystem C fluxes to an N addition gradient and revealed mechanisms underlying the dynamic responses. Results showed that NEE, ecosystem respiration (ER), and gross ecosystem production (GEP) all increased linearly with N addition rates in the first year of treatment but shifted to N saturation responses in the second year with the highest NEE (-7.77 ± 0.48 µmol m-2 s-1) occurring under an N addition rate of 8 gN m-2 yr-1. The saturation responses of NEE and GEP were caused by N-induced accumulation of standing litter, which limited light availability for plant growth under high N addition. The saturation response of ER was mainly due to an N-induced saturation response of aboveground plant respiration and decreasing soil microbial respiration along the N addition gradient, while decreases in soil microbial respiration under high N addition were caused by N-induced reductions in soil pH. We also found that various components of ER, including aboveground plant respiration, soil respiration, root respiration, and microbial respiration, responded differentially to the N addition gradient. These results reveal temporal dynamics of N impacts and the rapid shift in ecosystem C fluxes from N limitation to N saturation. Our findings bring evidence of short-term initial shifts in responses of ecosystem C fluxes to increases in N deposition, which should be considered when predicting long-term changes in ecosystem net C sequestration.

  9. Upscaling key ecosystem functions across the conterminous United States by a water‐centric ecosystem model

    Science.gov (United States)

    Ge Sun; Peter Caldwell; Asko Noormets; Steven G. McNulty; Erika Cohen; al. et.

    2011-01-01

    We developed a water‐centric monthly scale simulation model (WaSSI‐C) by integrating empirical water and carbon flux measurements from the FLUXNET network and an existing water supply and demand accounting model (WaSSI). The WaSSI‐C model was evaluated with basin‐scale evapotranspiration (ET), gross ecosystem productivity (GEP), and net ecosystem exchange (NEE)...

  10. Seasonal Variations of Carbon Dioxide, Water Vapor and Energy Fluxes in Tropical Indian Mangroves

    Directory of Open Access Journals (Sweden)

    Suraj Reddy Rodda

    2016-02-01

    Full Text Available We present annual estimates of the net ecosystem exchange (NEE of carbon dioxide (CO2 accumulated over one annual cycle (April 2012 to March 2013 in the world’s largest mangrove ecosystem, Sundarbans (India, using the eddy covariance method. An eddy covariance flux tower was established in April 2012 to study the seasonal variations of carbon dioxide fluxes due to soil and vegetation-atmosphere interactions. The half-hourly maximum of the net ecosystem exchange (NEE varied from −6 µmol·m−2·s−1 during the summer (April to June 2012 to −10 µmol·m−2·s−1 during the winter (October to December 2012, whereas the half-hourly maximum of H2O flux varied from 5.5 to 2.5 mmol·m−2·s−1 during October 2013 and July 2013, respectively. During the study period, the study area was a carbon dioxide sink with an annual net ecosystem productivity (NEP = −NEE of 249 ± 20 g·C m−2·year−1. The mean annual evapotranspiration (ET was estimated to be 1.96 ± 0.33 mm·day−1. The gap-filled NEE was also partitioned into Gross Primary Productivity (GPP and Ecosystem Respiration (Re. The total GPP and Re over the study area for the annual cycle were estimated to be1271 g C m−2·year−1 and 1022 g C m−2·year−1, respectively. The closure of the surface energy balance accounted for of about 78% of the available energy during the study period. Our findings suggest that the Sundarbans mangroves are currently a substantial carbon sink, indicating that the protection and management of these forests would lead as a strategy towards reduction in carbon dioxide emissions.

  11. Increasing the Intelligence of Virtual Sales Assistants through Knowledge Modeling Techniques

    OpenAIRE

    Molina, Martin

    2001-01-01

    Shopping agents are web-based applications that help consumers to find appropriate products in the context of e-commerce. In this paper we argue about the utility of advanced model-based techniques that recently have been proposed in the fields of Artificial Intelligence and Knowledge Engineering, in order to increase the level of support provided by this type of applications. We illustrate this approach with a virtual sales assistant that dynamically configures a product according to the nee...

  12. The Way the Wind Blows Matters to Ecosystem Water Use Efficiency

    Science.gov (United States)

    Montaldo, N.; Oren, R.

    2015-12-01

    In many regions, atmospheric conditions change frequently with shifts of wind direction, extending maritime influences far inland or continental influences to coastal ecosystems. Climate models predict changes in both wind direction and velocity; these changes could potentially impact ecosystems mass and energy exchanges with the atmosphere. Using climate and ecosystem-scale eddy-covariance data from Sardinia, we evaluated whether the frequency of certain wind characteristics, potentially improving ecosystem CO2 uptake, have changed over five decades, and whether these characteristics are indeed linked to ecosystem gas-exchange responses of the studied ecosystem. The analyses shows that days dominated by summer Mistral winds decreased on average 3% per decade, and that wind direction affects biosphere-atmosphere exchange of carbon but not water. High velocity cool Mistral winds from continental Europe treble vapor pressure deficit (D) as they cross the island. In contrast, arriving with a similar D, lower velocity, warmer Saharan Sirocco winds heat up, thus increasing D five-fold only 50 km inland. Over a mixed ecosystem (grass-wild olive), while soil moisture was low and constant, daytime net carbon exchange (NEE) averaged 2.3-fold higher in Mistral than Sirocco days, largely reflecting the theoretically expected response of canopy conductance (gc) to variation of D. Because the product of gc and D encodes the key ecosystem compensatory mechanism, the reciprocal gc-D response maintained similar ecosystem evapotranspiration (E). Thus, summertime ecosystem water-use efficiency (W=NEE/E), was ~66% higher during Mistral than other days. The historical decrease of Mistral frequency reduced the estimated summertime NEE >30 %. The analyses demonstrate that alteration of dominance of air masses predicted with future climate will amplify or negate the positive effect of increased atmospheric [CO2] on W, and should be considered when assessing climate change impact on NEE.

  13. RETURN - employability and E-Learning: start working effectively after parantal leave

    OpenAIRE

    Liening, Andreas; Mittelstädt, Ewald; Wiepcke, Claudia

    2007-01-01

    Doing business today means that one encounters new challenges: globalisation, mastery of advancements in information and communication technology, and adaptation to increasing buyer’s markets. For companies to compete in this environment, they must manage their knowledge and human capital effectively, which includes on-going on-the-job training for employee competency and skill mastery. Employees returning after parental leave are a special target group for this training: they nee...

  14. Evaluation of Areas for Off-Road Recreational Motorcycle Use. Volume I. Evaluation Method.

    Science.gov (United States)

    1980-11-01

    r , % 4 - e d I - A:T J N .Cf ii𔃿 T- ’’ a,,’’Aq’nee-,N I t’ NN-M V - T N o al I ’brtas -qee , " N i,’ ’A n, e i ’ no neC l’ DALN-M0 PRC Cuca -.T1T

  15. Using social responsibility to obtain employees´ commitment

    OpenAIRE

    Vittor Santillan, Paola Rosa

    2011-01-01

    Masteroppgave i økonomi og administrasjon - Universitetet i Agder 2011 I remember the past semester in class of Strategic Marketing Management, the topic of the day was “Resource Dependent Theory” and the professor started to lecture saying: ... “A company is a collection of resource: physical resources, human resources and financial resources. The way how to organize them produce capabilities and the more capabilities in a company the more sustainable competitive advantage. If you nee...

  16. Protein N-glycosylation in eukaryotic microalgae and its impact on the production of nuclear expressed biopharmaceuticals

    OpenAIRE

    Mathieu-Rivet, Elodie; Kiefer-Meyer, Marie-Christine; Vanier, Gaëtan; Ovide, Clément; Burel, Carole; Lerouge, Patrice; Bardor, Muriel

    2014-01-01

    Microalgae are currently used for the production of food compounds. Recently, few microalgae species have been investigated as potential biofactories for the production of biopharmaceuticals. Indeed in this context, microalgae are cheap, classified as Generally Recognized As Safe (GRAS) organisms and can be grown easily. However, problems remain to be solved before any industrial production of microalgae-made biopharmaceuticals. Among them, post-translational modifications of the proteins nee...

  17. Spaceport Command and Control System User Interface Testing

    Science.gov (United States)

    Huesman, Jacob

    2016-01-01

    The Spaceport Command and Control System will be the National Aeronautics and Space Administration's newest system for launching commercial and government owned spacecraft. It's a large system with many parts all in need of testing. To improve upon testing already done by NASA engineers, the Engineering Directorate, Electrical Division (NE-E) of Kennedy Space Center has hired a group of interns each of the last few semesters to develop novel ways of improving the testing process.

  18. Needs, Difficulties and Coping Mechanisms of Women as Professionals and as Managers of Households

    OpenAIRE

    Perlita C. Custodio; Loureli C. Siy

    2017-01-01

    The study examined the needs, difficulties and coping mechanisms of women professionals. A researcher-made questionnaire was utilized and administered to women professionals in selected private schools in the Philippines. Five hundred thirty-four usable questionnaires were retrieved and analyzed using frequency, percentage, mean, simple ranking and analysis of variance (ANOVA). Findings indicate that respondents consider spiritual and aesthetic needs, intellectual or cognitive nee...

  19. Effectiveness of trigger point dry needling for plantar heel pain: a meta-analysis of seven randomized controlled trials

    OpenAIRE

    He C; Ma H

    2017-01-01

    Chunhui He,1,* Hua Ma2,* 1Internal Medicine of Traditional Chinese Medicine, 2Medical Image Center, The First Affiliated Hospital of Xinjiang Medical University, Wulumuqi, People’s Republic of China *These authors contributed equally to this work Background: Plantar heel pain can be managed with dry needling of myofascial trigger points (MTrPs); however, whether MTrP needling is effective remains controversial. Thus, we conducted this meta-analysis to evaluate the effect of MTrP nee...

  20. Wkład rodzin Dembińskich herbu Rawicz i Nieczuja w rozwój przemysłu w dobrach ziemskich Przysucha w XIX wieku

    OpenAIRE

    Zarychta-Wójcicka, Agnieszka

    2010-01-01

    The Dembiński family were the owners of acres in Przysucha in Opoczno country. They contributed considerably to the development of ore mining and metallurgy in this area. They found the wire and sword manufactory, gunnery and blast furnace followed by the iron processing factory and metal rolling mill. The most famous member of the Dembiński – Urszula nee Morsztyn Dembińska persisted in searching for new outlets, broadening the range of distributed go...

  1. Exploring Social Meaning in Online Bilingual Text through Social Network Analysis

    Science.gov (United States)

    2015-09-01

    p. 1). 30 GATE development began in 1995. As techniques for natural language processing ( NLP ) are investigated by the research community and...become part of the NLP repetoire, developers incorporate them with wrappers, which allow the output from GATE processes to be recognized as input by...University NEE Named Entity Extraction NLP natural language processing OSD Office of the Secretary of Defense POS parts of speech SBIR Small Business

  2. A synopsis of Peristrophe (Acanthaceae in southern Africa

    Directory of Open Access Journals (Sweden)

    K. Balkwill

    1996-12-01

    Full Text Available A synopsis of Peristrophe Nees (Acanthaceae in southern Africa is provided. Peristrophe comprises nine species, one with two subspecies in southern Africa. A key for identification and descriptions of species not included in recent literature are provided. Morphology of tertiary bracts,indumentum on stems and distribution is illustrated and diagnostic characters, distribution, habitat, flowering  time and conservation status are discussed for each species.

  3. Two-Dimensional Numerical Model of coupled Heat and Moisture Transport in Frost Heaving Soils.

    Science.gov (United States)

    1982-08-01

    approximation for diffusion oroblems is nee---. This is the main objective of the paper: to develop such a constant- * ~ actor which has the hhetprobability...The conseauences of the above results is that use of the proposed -j(It) - actor should result in a linear diffusion mass matrix lumped finite element...contents were assumed. Because of symmetry only half the tank was analyzed, where at the pipe centerline, zero heat flux in the x- direccion was

  4. 11. Normalization and residential services: The Vermont studies1

    OpenAIRE

    Burchard, Sara N.

    2017-01-01

    Normalization has had an immeasurable impact on human services, education, and the social fabric of North America since its introduction 25 years ago. It has revolutionized thinking about service delivery across the entire spectrum of human services. Normalization has changed how we view people with needs, how we view their place in our society, and how we view the role of human services. Public policy has moved from a position of removing people with mental-health, educational, or social nee...

  5. Military Wastes-to-Energy Applications,

    Science.gov (United States)

    1980-11-01

    materials; soiled and dirty. Plastics Film and rigid, polyvinyl chloride, poly- ethylene, styrene in packaging, housewares, furniture, toys, and nonwoven ...energy recovered from sewage sludge that also goes into the digester. This calculation also assumes that the filter cake residue from the digester is...pounds. d D l. i and nee dle. a Steam plant Slowdown, pool filter hachwash, and engine test call. 106 Table 58. Summary of Military Hazardous Waste

  6. Cross-Layer Dynamic Spectrum Map Management Framework for White Space Applications

    OpenAIRE

    Kim Jongman; Yoon Seungil; Lim Kyutae

    2010-01-01

    White space, unused TV spectrum, will be allowed for unlicensed use by wireless communication devices "the so called white space applications (WSAs)." WSAs retrieve a location-based spectrum map, a list of open white space channels, from a spectrum map server and can select one on the list as their operating channel for the broadband Internet access. However, since not only primary users such as TV broadcasting services use white space shortly or longly but also neighboring WSAs do, WSAs nee...

  7. Three-dimensional needle-tip localization by electric field potential and camera hybridization for needle electromyography exam robotic simulator

    OpenAIRE

    He, Siyu; Gomez-Tames, Jose; Yu, Wenwei

    2016-01-01

    Siyu He,1 Jose Gomez-Tames,1 Wenwei Yu1,2 1Medical System Engineering Department, Graduate School of Engineering, 2Center for Frontier Medical Engineering, Chiba University, Chiba, Japan Abstract: As one of neurological tests, needle electromygraphy exam (NEE) plays an important role to evaluate the conditions of nerves and muscles. Neurology interns and novice medical staff need repetitive training to improve their skills in performing the exam. However, no training systems are able to repro...

  8. New internet business initiatives in the context of change management

    OpenAIRE

    Sofronijević, Adam; Milićević, Vesna; Marković, Aleksandar

    2015-01-01

    The paper presents the changing role of the Internet as a framework of several new business initiatives. In the last five years the Internet has evolved from being just a useful tool to a force shaping business strategies and influencing long-term managerial decision making. The paper presents an analysis of several cutting edge business initiatives and relates the success opportunities they have with evolving features of the Internet. The growth of importance of the Internet stresses the nee...

  9. NATURAL ENEMIES OF DIURAPHIS NOXIA (STERNORRHYNCHA: APHIDIDAE IN SLOVAKIA

    Directory of Open Access Journals (Sweden)

    Peter TÓTH

    2009-11-01

    Full Text Available A study from 2002 documented the occurrence of natural enemies (parasitoid wasps, predatory fl ies, entomopathogenic fungi associated with colonies of the Russian wheat aphid, Diuraphis noxia (Kurdjumov, 1913 (Sternorrhyncha: Aphididae, in the spring barley fi elds in Slovakia. Parasitization by wasps was low (<5.5% with Diaeretiella rapae (McIntosh, 1855 the dominant hymenopterous parasitoid (91% of emerging wasps. The remaining parasitoid guild comprised of Aphidius ervi Haliday, 1834 Aphidius rhopalosiphi DeStefani, 1902, Aphidius picipes (Nees, 1811, Ephedrus plagiator (Nees, 1811, Praon volucre (Haliday, 1833 (Hymenoptera: Aphidiidae and two hyperparasites Asaphes suspensus (Nees, 1834 (Hymenoptera: Pteromalidae and Lygocerus spp. (Hymenoptera: Ceraphronidae. Predaceous midges (Diptera: Cecidomyiidae were consistently found with densities ranging from 0.1 to 2.5 larvae per aphid colony. The most abundant predaceous midge was Aphidoletes aphidimyza (Rondani, 1847, while Lestodiplosis sp. was recorded infrequently. Four syrphids, Episyrphus balteatus (De Geer, 1776, Melanostoma mellinum (L., 1758, Sphaerophoria rueppellii (Wiedemann, 1830, Sphaerophoria scripta (L., 1758 (Diptera: Syrphidae and one pathogenic fungus, Pandora neoaphidis (Remaudière et Hennebert Humber, were recorded.

  10. Comparing ecosystem and soil respiration: Review and key challenges of tower-based and soil measurements

    Energy Technology Data Exchange (ETDEWEB)

    Barba, Josep; Cueva, Alejandro; Bahn, Michael; Barron-Gafford, Greg A.; Bond-Lamberty, Benjamin; Hanson, Paul J.; Jaimes, Aline; Kulmala, Liisa; Pumpanen, Jukka; Scott, Russell L.; Wohlfahrt, Georg; Vargas, Rodrigo

    2018-02-01

    The net ecosystem exchange (NEE) is the difference between ecosystem CO2 assimilation and CO2 losses to the atmosphere. Ecosystem respiration (Reco), the efflux of CO2 from the ecosystem to the atmosphere, includes the soil-to-atmosphere carbon flux (i.e., soil respiration; Rsoil) and aboveground plant respiration. Therefore, Rsoil is a fraction of Reco and by definition has to be smaller than Reco at annual, seasonal and daily scales. However, several studies estimating Reco with the eddy covariance technique and measuring Rsoil within the footprint of the tower have reported higher Rsoil than Reco at different time scales. Here, we compare four different and contrasting ecosystems (from forest to grasslands, and from boreal to semiarid) to study whether, and under what conditions, measurements of Reco are lower than Rsoil. In general, both fluxes showed similar temporal patterns, but Reco was not consistently higher than Rsoil from daily to annual scales across sites. We identified several issues that apply for measuring NEE and measuring/upscaling Rsoil that could result in an underestimation of Reco and/or an overestimation of Rsoil. These issues are discussed based on (a) nighttime measurements of NEE, (b) Rsoil measurements, and (c) the interpretation of the functional relationships of these fluxes with temperature (i.e., Q10). We highlight that there is still a need for better integration of Rsoil with eddy covariance measurements to address challenges related to spatial and temporal variability of Reco and Rsoil.

  11. Effects of elevated CO2 and nitrogen deposition on ecosystem carbon fluxes on the Sanjiang plain wetland in Northeast China.

    Directory of Open Access Journals (Sweden)

    Jianbo Wang

    Full Text Available BACKGROUND: Increasing atmospheric CO2 and nitrogen (N deposition across the globe may affect ecosystem CO2 exchanges and ecosystem carbon cycles. Additionally, it remains unknown how increased N deposition and N addition will alter the effects of elevated CO2 on wetland ecosystem carbon fluxes. METHODOLOGY/PRINCIPAL FINDINGS: Beginning in 2010, a paired, nested manipulative experimental design was used in a temperate wetland of northeastern China. The primary factor was elevated CO2, accomplished using Open Top Chambers, and N supplied as NH4NO3 was the secondary factor. Gross primary productivity (GPP was higher than ecosystem respiration (ER, leading to net carbon uptake (measured by net ecosystem CO2 exchange, or NEE in all four treatments over the growing season. However, their magnitude had interannual variations, which coincided with air temperature in the early growing season, with the soil temperature and with the vegetation cover. Elevated CO2 significantly enhanced GPP and ER but overall reduced NEE because the stimulation caused by the elevated CO2 had a greater impact on ER than on GPP. The addition of N stimulated ecosystem C fluxes in both years and ameliorated the negative impact of elevated CO2 on NEE. CONCLUSION/SIGNIFICANCE: In this ecosystem, future elevated CO2 may favor carbon sequestration when coupled with increasing nitrogen deposition.

  12. La colaboración entre maestros/maestras y padres/madres para atender a la diversidad en las instituciones educativas

    Directory of Open Access Journals (Sweden)

    Ronald Soto Calderón

    2004-01-01

    Full Text Available En este artículo se resalta la importancia de un trabajo conjunto entre los padres y madres de familia de personas con necesidades educativas especiales y los docentes, y las diferentes formas en que esta labor se puede realizar. También se comentan los diferentes planos en los que se puede llevar a cabo un trabajo cooperativo, de tal manera que lo importante siempre se enfoque a la atención educativa de los estudiantes con NEE, se mencionan también algunos puntos que pueden ser tomados en cuenta para evitar las diferencias en las actuaciones tanto de los padres y madres de familia como de los docentes, de los estudiantes con NEE en las situaciones que le competen a las instituciones. Se considera por parte de los autores, que un trabajo coordinado, colaborativo y consciente de todas las partes que participan en el desarrollo del proceso aprendizaje de personas con NEE, siempre se verá reflejado en el éxito y realización de los potencialidades de todas las personas, y el derecho a la participación de las personas en igualdad y equiparación de oportunidades

  13. Water- and plant-mediated responses of ecosystem carbon fluxes to warming and nitrogen addition on the Songnen grassland in northeast China.

    Directory of Open Access Journals (Sweden)

    Li Jiang

    Full Text Available BACKGROUND: Understanding how grasslands are affected by a long-term increase in temperature is crucial to predict the future impact of global climate change on terrestrial ecosystems. Additionally, it is not clear how the effects of global warming on grassland productivity are going to be altered by increased N deposition and N addition. METHODOLOGY/PRINCIPAL FINDINGS: In-situ canopy CO(2 exchange rates were measured in a meadow steppe subjected to 4-year warming and nitrogen addition treatments. Warming treatment reduced net ecosystem CO(2 exchange (NEE and increased ecosystem respiration (ER; but had no significant impacts on gross ecosystem productivity (GEP. N addition increased NEE, ER and GEP. However, there were no significant interactions between N addition and warming. The variation of NEE during the four experimental years was correlated with soil water content, particularly during early spring, suggesting that water availability is a primary driver of carbon fluxes in the studied semi-arid grassland. CONCLUSION/SIGNIFICANCE: Ecosystem carbon fluxes in grassland ecosystems are sensitive to warming and N addition. In the studied water-limited grassland, both warming and N addition influence ecosystem carbon fluxes by affecting water availability, which is the primary driver in many arid and semiarid ecosystems. It remains unknown to what extent the long-term N addition would affect the turn-over of soil organic matter and the C sink size of this grassland.

  14. Chemical Fingerprinting of the Fragrant Volatiles of Nineteen Indian Cultivars of Cymbopogon Spreng. (Poaceae

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    Rajendra C. Padalia

    2011-01-01

    Full Text Available The essential oil compositions of total nineteen cultivars of Cymbopogon Spreng. (Poaceae species viz. C. martinii (Roxb. Wats. var. motia Burk., C. flexuosus Nees ex Steud, C. winterinus Jowitt., C. pendulus Nees ex Steud. and a hybrid of C. khasianus (Hack Stapf. ex Bor and C. pendulus Nees ex Steud. were examined and compared using capillary GC and GC-MS . The analysis led to the identification of 48 constituents forming 90.1% to 99.7% of their total oil compositions with monoterpenoids (78.9% to 97.4% as the most exclusive constituents. The comparative results showed considerable variation in the qualitative and quantitative compositions of essential oils from nineteen different cultivars of the studied Cymbopogon species. On the basis of chemical similarity the cultivars of genus Cymbopogon was divided into five chemical variants/groups within two series viz. Citrati and Rusae. The volatile profile of existing cultivars of Cymbopogon are useful for their commercial utilization as they possess range of essential oils and aroma chemicals used in perfumery, flavour, pharmaceutical and other allied industries. Moreover, the marker constituents in their essential oils may be utilized as an important tool in oil authentication.

  15. Karyotypes of parasitic wasps of the family Eulophidae (Hymenoptera) attacking leaf-mining Lepidoptera (Gracillariidae, Gelechiidae).

    Science.gov (United States)

    Gokhman, Vladimir E; Yefremova, Zoya A; Yegorenkova, Ekaterina N

    2014-01-01

    Karyotypes of eleven parasitoid species of the family Eulophidae were examined, namely, Chrysocharis laomedon (Walker, 1839) (2n = 10), Chrysocharis sp. aff. laomedon (n = 5, 2n = 10), Chrysocharis sp. aff. albipes (Ashmead, 1904) (2n = 12), Mischotetrastichus petiolatus (Erdös, 1961) (n = 6, 2n = 12), Minotetrastichus frontalis (Nees, 1834) (n = 5, 2n = 10), Cirrospilus pictus (Nees, 1834) (2n = 12), Hyssopus geniculatus (Hartig, 1838) (2n = 16), Sympiesis gordius (Walker, 1839) (2n = 12), S. sericeicornis (Nees, 1834) (2n = 12), Pnigalio agraules (Walker, 1839) (2n = 12 + 0-2B) and Pnigalio gyamiensis Myartseva & Kurashev, 1990 (2n = 12 + 0-6B) reared from Phyllonorycter acerifoliella (Zeller, 1839), Ph. apparella (Herrich-Schäffer, 1855), Ph. issikii (Kumata, 1963) (Gracillariidae) and Chrysoesthia sexguttella (Thunberg, 1794) (Gelechiidae). Chromosome sets of all species except P. agraules and P. gyamiensis were studied for the first time. B chromosomes were detected in the two latter species; in P. gyamiensis, the maximum number of B chromosomes represents the highest value known for parasitic wasps to date.

  16. The role of isohydric and anisohydric species in determining ecosystem-scale response to severe drought.

    Science.gov (United States)

    Roman, D T; Novick, K A; Brzostek, E R; Dragoni, D; Rahman, F; Phillips, R P

    2015-11-01

    Ongoing shifts in the species composition of Eastern US forests necessitate the development of frameworks to explore how species-specific water-use strategies influence ecosystem-scale carbon (C) cycling during drought. Here, we develop a diagnostic framework to classify plant drought-response strategies along a continuum of isohydric to anisohydric regulation of leaf water potential (Ψ(L)). The framework is applied to a 3-year record of weekly leaf-level gas exchange and Ψ measurements collected in the Morgan-Monroe State Forest (Indiana, USA), where continuous observations of the net ecosystem exchange of CO2 (NEE) have been ongoing since 1999. A severe drought that occurred in the middle of the study period reduced the absolute magnitude of NEE by 55%, though species-specific responses to drought conditions varied. Oak species were characterized by anisohydric regulation of Ψ(L) that promoted static gas exchange throughout the study period. In contrast, Ψ(L) of the other canopy dominant species was more isohydric, which limited gas exchange during the drought. Ecosystem-scale estimates of NEE and gross ecosystem productivity derived by upscaling the leaf-level data agreed well with tower-based observations, and highlight how the fraction of isohydric and anisohydric species in forests can mediate net ecosystem C balance.

  17. Karyotypes of parasitic wasps of the family Eulophidae (Hymenoptera attacking leaf-mining Lepidoptera (Gracillariidae, Gelechiidae

    Directory of Open Access Journals (Sweden)

    Vladimir Gokhman

    2014-02-01

    Full Text Available Karyotypes of eleven parasitoid species of the family Eulophidae were examined, namely, Chrysocharis laomedon (Walker, 1839 (2n = 10, Chrysocharis sp. aff. laomedon (n = 5, 2n = 10, Chrysocharis sp. aff. albipes (Ashmead, 1904 (2n = 12, Mischotetrastichus petiolatus (Erdös, 1961 (n = 6, 2n = 12, Minotetrastichus frontalis (Nees, 1834 (n = 5, 2n = 10, Cirrospilus pictus (Nees, 1834 (2n = 12, Hyssopus geniculatus (Hartig, 1838 (2n = 16, Sympiesis gordius (Walker, 1839 (2n = 12, S. sericeicornis (Nees, 1834 (2n = 12, Pnigalio agraules (Walker, 1839 (2n = 12 + 0–2B and Pnigalio gyamiensis Myartseva & Kurashev, 1990 (2n = 12 + 0–6B reared from Phyllonorycter acerifoliella (Zeller, 1839, Ph. apparella (Herrich-Schäffer, 1855, Ph. issikii (Kumata, 1963 (Gracillariidae and Chrysoesthia sexguttella (Thunberg, 1794 (Gelechiidae. Chromosome sets of all species except P. agraules and P. gyamiensis were studied for the first time. B chromosomes were detected in the two latter species; in P. gyamiensis, the maximum number of B chromosomes represents the highest value known for parasitic wasps to date.

  18. Typhoons exert significant but differential impact on net carbon ecosystem exchange of subtropical mangrove ecosystems in China

    Science.gov (United States)

    Chen, H.; Lu, W.; Yan, G.; Yang, S.; Lin, G.

    2014-06-01

    Typhoons are very unpredictable natural disturbances to subtropical mangrove forests in Asian countries, but litter information is available on how these disturbances affect ecosystem level carbon dioxide (CO2) exchange of mangrove wetlands. In this study, we examined short-term effect of frequent strong typhoons on defoliation and net ecosystem CO2 exchange (NEE) of subtropical mangroves, and also synthesized 19 typhoons during a 4-year period between 2009 and 2012 to further investigate the regulation mechanisms of typhoons on ecosystem carbon and water fluxes following typhoon disturbances. Strong wind and intensive rainfall caused defoliation and local cooling effect during typhoon season. Daily total NEE values were decreased by 26-50% following some typhoons (e.g. W28-Nockten, W35-Molave and W35-Lio-Fan), but were significantly increased (43-131%) following typhoon W23-Babj and W38-Megi. The magnitudes and trends of daily NEE responses were highly variable following different typhoons, which were determined by the balance between the variances of gross ecosystem production (GEP) and ecosystem respiration (RE). Furthermore, results from our synthesis indicated that the landfall time of typhoon, wind speed and rainfall were the most important factors controlling the CO2 fluxes following typhoon events. These findings not only indicate that mangrove ecosystems have strong resilience to the frequent typhoon disturbances, but also demonstrate the damage of increasing typhoon intensity and frequency on subtropical mangrove ecosystems under future global climate change scenarios.

  19. Nanobiosensing with Arrays and Ensembles of Nanoelectrodes

    Directory of Open Access Journals (Sweden)

    Najmeh Karimian

    2016-12-01

    Full Text Available Since the first reports dating back to the mid-1990s, ensembles and arrays of nanoelectrodes (NEEs and NEAs, respectively have gained an important role as advanced electroanalytical tools thank to their unique characteristics which include, among others, dramatically improved signal/noise ratios, enhanced mass transport and suitability for extreme miniaturization. From the year 2000 onward, these properties have been exploited to develop electrochemical biosensors in which the surfaces of NEEs/NEAs have been functionalized with biorecognition layers using immobilization modes able to take the maximum advantage from the special morphology and composite nature of their surface. This paper presents an updated overview of this field. It consists of two parts. In the first, we discuss nanofabrication methods and the principles of functioning of NEEs/NEAs, focusing, in particular, on those features which are important for the development of highly sensitive and miniaturized biosensors. In the second part, we review literature references dealing the bioanalytical and biosensing applications of sensors based on biofunctionalized arrays/ensembles of nanoelectrodes, focusing our attention on the most recent advances, published in the last five years. The goal of this review is both to furnish fundamental knowledge to researchers starting their activity in this field and provide critical information on recent achievements which can stimulate new ideas for future developments to experienced scientists.

  20. Carbon dioxide and methane fluxes in grazed and undisturbed mountain peatlands in the Ecuadorian Andes

    Directory of Open Access Journals (Sweden)

    M.E. Sánchez

    2017-10-01

    Full Text Available Peatlands are widespread throughout the tropical Andean páramo. Despite the large carbon stocks in these ecosystems, carbon dioxide (CO2 and methane (CH4 flux data are lacking. In addition, cattle grazing is widespread in the páramo and could alter gas fluxes. Therefore, our objectives were to measure CO2 and CH4 fluxes with the static chamber technique in an undisturbed and in an intensively cattle grazed peatland in the mountains of Ecuador. We found that hummocks in the undisturbed site had higher net ecosystem exchange (NEE, gross primary production (GPP, ecosystem respiration (ER, and CH4 fluxes, compared to lawns. In contrast, microtopography at the grazed site did not predict CO2 fluxes, whereas vegetation cover was correlated for all three metrics (NEE, ER, and GPP. At low vegetation cover, NEE was positive (losing carbon. CH4 emissions in the undisturbed site were low (8.1 mg CH4 m-2 d-1. In contrast, CH4 emissions at the grazed site were much greater (132.3 mg CH4 m-2 d-1. This is probably attributable to trampling and nutrient inputs from cattle. In summary, the two peatlands differed greatly in CO2 and CH4 exchange rates, which could be due to the variation in climate and hydrology, or alternatively to intensive grazing by cattle.

  1. Mediterranean savanna of Acacia caven (Mol) is still a sink of CO2 in spite of severe hydrological drought conditions

    Science.gov (United States)

    Bravo-Martínez, F.; Meza, F. J.

    2012-12-01

    An eddy covariance tower was set up to monitor net ecosystem exchange (NEE) on a mediterranean shrubland of Acacia caven (Mol) in October 2010. This ecosystem (commonly referred as "espinal") is one of the most abundant land covers of Chile's central valley (2.000.000 ha). The last two years (2010-2011) were characterized by the occurrence of a severe drought (rainfall deficit 56%) and a small increase in temperature evaluated using a climatic change index (Peterson, 2005). We also detected a strong reduction in vegetation index during this period (evaluated using MODIS imagery). The historical analysis of the enhanced vegetation index (EVI) and leaf area index (LAI) showed that water status of the acacia savanna were at a minimum during this period (record of 14 years of data). The annual balance of NEE of 2011 was -54gC m-2 y-1, which means that the espinal is a sink of atmospheric CO2 notwithstanding the many stressors on photosynthesis. Monthly analysis of NEE shows the strong dependence of ecosystem fluxes on phenological state. Maximum rates of assimilation are a consequence of grassland activity, whereas secondary picks during the year (late spring and early autumn) are attributed to the semideciduos leaf of A. caven. Climatic conditions during the study season, confirm the tremendous plasticity of Acacia caven and its role as a colonizer of degraded sclerophyll forest because it adaptation to water and thermal stress.

  2. Comparing net ecosystem carbon dioxide exchange at adjacent commercial bioenergy and conventional cropping systems in Lincolnshire, United Kingdom

    Science.gov (United States)

    Morrison, Ross; Brooks, Milo; Evans, Jonathan; Finch, Jon; Rowe, Rebecca; Rylett, Daniel; McNamara, Niall

    2016-04-01

    The conversion of agricultural land to bioenergy plantations represents one option in the national and global effort to reduce greenhouse gas emissions whilst meeting future energy demand. Despite an increase in the area of (e.g. perennial) bioenergy crops in the United Kingdom and elsewhere, the biophysical and biogeochemical impacts of large scale conversion of arable and other land cover types to bioenergy cropping systems remain poorly characterised and uncertain. Here, the results of four years of eddy covariance (EC) flux measurements of net ecosystem CO2 exchange (NEE) obtained at a commercial farm in Lincolnshire, United Kingdom (UK) are reported. CO2 flux measurements are presented and compared for arable crops (winter wheat, oilseed rape, spring barely) and plantations of the perennial biofuel crops Miscanthus x. giganteus (C4) and short rotation coppice (SRC) willow (Salix sp.,C3). Ecosystem light and temperature response functions were used to analyse and compare temporal trends and spatial variations in NEE across the three land covers. All three crops were net in situ sinks for atmospheric CO2 but were characterised by large temporal and between site variability in NEE. Environmental and biological controls driving the spatial and temporal variations in CO2 exchange processes, as well as the influences of land management, will be analysed and discussed.

  3. NIÑOS y adolescentes con necesidades educativas especiales

    Directory of Open Access Journals (Sweden)

    S. Isabel Margarita López, Dra.

    2015-01-01

    Full Text Available Se viven tiempos de grandes y rápidos cambios socioeconómicos, culturales y tecnológicos. Las sociedades actuales promueven la equidad en un sentido amplio, afirmando el valor de la diversidad y la necesidad de la inclusión. Los conceptos de Necesidades Educativas Especiales (NEE y de inclusión cobran fuerza, con la reafirmación del derecho fundamental de todos los niños/as y jóvenes a acceder a la educación, reconociendo que cada uno de ellos “posee características, intereses, capacidades y necesidades de aprendizajes que le son propios”. En este artículo se revisan los conceptos actuales de discapacidad, NEE e inclusión, las principales condiciones que afectan a niños y adolescentes que tienen NEE y se discute en torno a las diferentes modalidades y herramientas pedagógicas actualmente disponibles en el sistema educativo chileno para cumplir esta tarea.

  4. The impact of extreme drought on the biofuel feedstock production

    Science.gov (United States)

    hussain, M.; Zeri, M.; Bernacchi, C.

    2013-12-01

    Miscanthus (Miscanthus x giganteus) and Switchgrass (Panicum virgatum) have been identified as the primary targets for second-generation cellulosic biofuel crops. Prairie managed for biomass is also considered as one of the alternative to conventional biofuel and promised to provide ecosystem services, including carbon sequestration. These perennial grasses possess a number of traits that make them desirable biofuel crops and can be cultivated on marginal lands or interspersed with maize and soybean in the Corn Belt region. The U.S. Corn Belt region is the world's most productive and expansive maize-growing region, approximately 20% of the world's harvested corn hectares are found in 12 Corn Belt states. The introduction of a second generation cellulosic biofuels for biomass production in a landscape dominated by a grain crop (maize) has potential implications on the carbon and water cycles of the region. This issue is further intensified by the uncertainty in the response of the vegetation to the climate change induced drought periods, as was seen during the extreme droughts of 2011 and 2012 in the Midwest. The 2011 and 2012 growing seasons were considered driest since the 1932 dust bowl period; temperatures exceeded 3.0 °C above the 50- year mean and precipitation deficit reached 50 %. The major objective of this study was to evaluate the drought responses (2011 and 2012) of corn and perennial species at large scale, and to determine the seasonability of carbon and water fluxes in the response of controlling factors. We measured net CO2 ecosystem exchange (NEE) and water fluxes of maize-maize-soybean, and perennial species such as miscanthus, switchgrass and mixture of prairie grasses, using eddy covariance in the University of Illinois energy farm at Urbana, IL. The data presented here were for 5 years (2008- 2012). In the first two years, higher NEE in maize led to large CO2 sequestration. NEE however, decreased in dry years, particularly in 2012. On the other

  5. Carbon and Water Budgets in Multiple Wheat-Based Cropping Systems in the Inland Pacific Northwest US: Comparison of CropSyst Simulations with Eddy Covariance Measurements

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    Jinshu Chi

    2017-05-01

    Full Text Available Accurate carbon and water flux simulations for croplands are greatly dependent on high quality representation of management practices and meteorological conditions, which are key drivers of the surface-atmosphere exchange processes. Fourteen site-years of carbon and water fluxes were simulated using the CropSyst model over four agricultural sites in the inland Pacific Northwest (iPNW US from October 1, 2011 to September 30, 2015. Model performance for field-scale net ecosystem exchange of CO2 (NEE and evapotranspiration (ET was evaluated by comparing simulations with long-term eddy covariance measurements. The model captured the temporal variations of NEE and ET reasonably well with an overall r of 0.78 and 0.80, and a low RMSE of 1.82 g C m−2 d−1 and 0.84 mm d−1 for NEE and ET, respectively. The model slightly underestimated NEE and ET by 0.51 g C m−2 d−1 and 0.09 mm d−1, respectively. ET simulations showed better agreement with eddy covariance measurements than NEE. The model performed much better for the sites with detailed initial conditions (e.g., SOC content and management practice information (e.g., tillage type. The CropSyst results showed that the winter wheat fields could be annual net carbon sinks or close to neutral with the net ecosystem carbon balance (NECB ranging from 92 to −17 g C m−2, while the spring crop fields were net carbon sources or neutral with an annual NECB of −327 to −3 g C m−2. Simulations for the paired tillage sites showed that the no-till site resulted in lower CO2 emissions for the crop rotations of winter wheat-spring garbanzo, but had higher carbon loss into the atmosphere for spring canola compared to the conventional tillage site. Water budgets did not differ significantly between the two tillage systems. Winter wheat in the high-rainfall area had higher crop yields and water use efficiency but emitted larger amounts of CO2 into the atmosphere than in the low-rainfall area. Based on

  6. The carbon fluxes in different successional stages: modelling the dynamics of tropical montane forests in South Ecuador

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    Sebastian Paulick

    2017-05-01

    Full Text Available Background Tropical forests play an important role in the global carbon (C cycle. However, tropical montane forests have been studied less than tropical lowland forests, and their role in carbon storage is not well understood. Montane forests are highly endangered due to logging, land-use and climate change. Our objective was to analyse how the carbon balance changes during forest succession. Methods In this study, we used a method to estimate local carbon balances that combined forest inventory data with process-based forest models. We utilised such a forest model to study the carbon balance of a tropical montane forest in South Ecuador, comparing two topographical slope positions (ravines and lower slopes vs upper slopes and ridges. Results The simulation results showed that the forest acts as a carbon sink with a maximum net ecosystem exchange (NEE of 9.3 Mg C∙(ha∙yr−1 during its early successional stage (0–100 years. In the late successional stage, the simulated NEE fluctuated around zero and had a variation of 0.77 Mg C∙(ha∙yr –1. The simulated variability of the NEE was within the range of the field data. We discovered several forest attributes (e.g., basal area or the relative amount of pioneer trees that can serve as predictors for NEE for young forest stands (0–100 years but not for those in the late successional stage (500–1,000 years. In case of young forest stands these correlations are high, especially between stand basal area and NEE. Conclusion In this study, we used an Ecuadorian study site as an example of how to successfully link a forest model with forest inventory data, for estimating stem-diameter distributions, biomass and aboveground net primary productivity. To conclude, this study shows that process-based forest models can be used to investigate the carbon balance of tropical montane forests. With this model it is possible to find hidden relationships between forest attributes and forest carbon fluxes

  7. Altitude or slope position - gaseous carbon cycling on UK blanket peat bogs

    Science.gov (United States)

    Dixon, Simon; Rowson, James; Worrall, Fred

    2010-05-01

    Blanket peat accounts for 87% of Britain's total peatlands and represents one of the UK's largest terrestrial carbon stores. For peatlands to accumulate carbon the net ecosystem exchange of CO2 (NEE) must be negative with respect to the atmosphere. Unlike many other peatlands, upland blanket peat bogs in the UK are draped across hillsides and so it could be that both altitude and slope position are significant controls upon the magnitude and direction of NEE. The role that altitude and slope position play on NEE in upland blanket peat is poorly constrained on a local scale. Thus a hillslope transect was set up to measure how the gaseous exchange of CO2 varies across altitude and with slope position. The slope-transect consisted of 4 sites, in the English Peak District, with three replicates per site. The transect spanned the entire margin of peat occurrence on the hillside, from the summit (447m ASL) to the lowest occurrence of peat at (378m ASL). The sites were positioned to sample each of the distinct points of the variation in slope from the flat top, to the point of slope steepening, to the point of slope leveling to the final flattening out of the slope. Each site was located in Calluna vulgaris of similar age and in the same growth phase (degenerate). Data were gathered for a year in order to sample a complete seasonal cycle. The results of analysis by ANOVA showed that altitudinal effects were either not present or so small as to be masked by other effects. However both NER and GPP seemed to be linked to slope position. ANOVA and post hoc Tukey testing showed that only the site on the point of slope steepening was significantly different to the other sites with NER being 47% higher and GPP being 63% greater than the average of the other sites. But the elevated rates of GPP and NER cancelled each other out resulting in a non-significant 3% greater rate of overall NEE from the point of slope steepening. Another slope position effect observed was that of hill

  8. Sensitivity of temperate desert steppe carbon exchange to seasonal droughts and precipitation variations in Inner Mongolia, China.

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    Fulin Yang

    Full Text Available Arid grassland ecosystems have significant interannual variation in carbon exchange; however, it is unclear how environmental factors influence carbon exchange in different hydrological years. In this study, the eddy covariance technique was used to investigate the seasonal and interannual variability of CO₂ flux over a temperate desert steppe in Inner Mongolia, China from 2008 to 2010. The amounts and times of precipitation varied significantly throughout the study period. The precipitation in 2009 (186.4 mm was close to the long-term average (183.9±47.6 mm, while the precipitation in 2008 (136.3 mm and 2010 (141.3 mm was approximately a quarter below the long-term average. The temperate desert steppe showed carbon neutrality for atmospheric CO₂ throughout the study period, with a net ecosystem carbon dioxide exchange (NEE of -7.2, -22.9, and 26.0 g C m⁻² yr⁻¹ in 2008, 2009, and 2010, not significantly different from zero. The ecosystem gained more carbon in 2009 compared to other two relatively dry years, while there was significant difference in carbon uptake between 2008 and 2010, although both years recorded similar annual precipitation. The results suggest that summer precipitation is a key factor determining annual NEE. The apparent quantum yield and saturation value of NEE (NEE(sat and the temperature sensitivity coefficient of ecosystem respiration (R(eco exhibited significant variations. The values of NEE(sat were -2.6, -2.9, and -1.4 µmol CO₂ m⁻² s⁻¹ in 2008, 2009, and 2010, respectively. Drought suppressed both the gross primary production (GPP and R(eco, and the drought sensitivity of GPP was greater than that of R(eco. The soil water content sensitivity of GPP was high during the dry year of 2008 with limited soil moisture availability. Our results suggest the carbon balance of this temperate desert steppe was not only sensitive to total annual precipitation, but also to its seasonal distribution.

  9. Biophysical controls on net ecosystem CO2 exchange over a semiarid shrubland in northwest China

    Science.gov (United States)

    Jia, X.; Zha, T. S.; Wu, B.; Zhang, Y. Q.; Gong, J. N.; Qin, S. G.; Chen, G. P.; Qian, D.; Kellomäki, S.; Peltola, H.

    2014-09-01

    The carbon (C) cycling in semiarid and arid areas remains largely unexplored, despite the wide distribution of drylands globally. Rehabilitation practices have been carried out in many desertified areas, but information on the C sequestration capacity of recovering vegetation is still largely lacking. Using the eddy-covariance technique, we measured the net ecosystem CO2 exchange (NEE) over a recovering shrub ecosystem in northwest China throughout 2012 in order to (1) quantify NEE and its components and to (2) examine the dependence of C fluxes on biophysical factors at multiple timescales. The annual budget showed a gross ecosystem productivity (GEP) of 456 g C m-2 yr-1 (with a 90% prediction interval of 449-463 g C m-2 yr-1) and an ecosystem respiration (Re) of 379 g C m-2 yr-1 (with a 90% prediction interval of 370-389 g C m-2 yr-1), resulting in a net C sink of 77 g C m-2 yr-1 (with a 90% prediction interval of 68-87 g C m-2 yr-1). The maximum daily NEE, GEP and Re were -4.7, 6.8 and 3.3 g C m-2 day-1, respectively. Both the maximum C assimilation rate (i.e., at the optimum light intensity) and the quantum yield varied over the growing season, being higher in summer and lower in spring and autumn. At the half-hourly scale, water deficit exerted a major control over daytime NEE, and interacted with other stresses (e.g., heat and photoinhibition) in constraining C fixation by the vegetation. Low soil moisture also reduced the temperature sensitivity of Re (Q10). At the synoptic scale, rain events triggered immediate pulses of C release from the ecosystem, followed by peaks of CO2 uptake 1-2 days later. Over the entire growing season, leaf area index accounted for 45 and 65% of the seasonal variation in NEE and GEP, respectively. There was a linear dependence of daily Re on GEP, with a slope of 0.34. These results highlight the role of abiotic stresses and their alleviation in regulating C cycling in the face of an increasing frequency and intensity of extreme

  10. Regional assimilation of CO2 and δ13C surface data to assess terrestrial biosphere models under drought stress

    Science.gov (United States)

    van der Velde, I. R.; Miller, J. B.; Alden, C. B.; Andrews, A. E.; Schaefer, K. M.; Peters, W.; Tans, P. P.; Vaughn, B. H.; White, J. W. C.

    2016-12-01

    Observed atmospheric carbon dioxide (CO2) and the ratios of its stable isotopologue 13CO2/12CO2 (δ13C) contain unique signals of large-scale drought stress that affect the biosphere. When plants experience physiological stress due to heat and drought at leaf level they respond by closing their stomata. This is a safety mechanism that prevents excessive water loss at the expense of carbon uptake, and it changes the overall water-use efficiency. During photosynthesis, 12CO2 is preferentially assimilated over 13CO2, leaving the atmosphere enriched in 13CO2. Water stress slightly changes the ratio of 13CO2 and 12CO2 molecules being removed from the atmosphere, i.e., a reduction of canopy isotope discrimination (Δ), and its changes are evident in atmospheric δ13C.To improve our understanding of the coupled vegetation-atmosphere system we are developing an ensemble Kalman filter assimilation of high precision measurements of CO2 and δ13C from air samples collected over North America. It uses footprints provided by WRF-STILT that allows for efficient atmospheric transport simulations on a much higher horizontal resolution than with a global Eulerian transport model. To force consistency with atmospheric CO2 and δ13C observations we will optimize regional net terrestrial CO2 exchange (NEE) and Δ from a terrestrial biosphere model. We will carefully evaluate the sensitivity of the optimized parameters to uncertainties in the terrestrial biosphere fluxes, observations, time/space aggregation methods, and boundary conditions. Our main questions are: (i) what signal-to-noise in the data, as interpreted by the model, is large enough to robustly estimate Δ and NEE? and (ii) how do the optimized NEE and Δ that are based on the atmospheric constraint compare with the predicted NEE and Δ that are based on biophysical parameterizations? Our ability to accurately predict the responses of the terrestrial biosphere to changing humidity and soil moisture regimes is currently

  11. ORCHIDEE-PEAT (revision 4596, a model for northern peatland CO2, water, and energy fluxes on daily to annual scales

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    C. Qiu

    2018-02-01

    Full Text Available Peatlands store substantial amounts of carbon and are vulnerable to climate change. We present a modified version of the Organising Carbon and Hydrology In Dynamic Ecosystems (ORCHIDEE land surface model for simulating the hydrology, surface energy, and CO2 fluxes of peatlands on daily to annual timescales. The model includes a separate soil tile in each 0.5° grid cell, defined from a global peatland map and identified with peat-specific soil hydraulic properties. Runoff from non-peat vegetation within a grid cell containing a fraction of peat is routed to this peat soil tile, which maintains shallow water tables. The water table position separates oxic from anoxic decomposition. The model was evaluated against eddy-covariance (EC observations from 30 northern peatland sites, with the maximum rate of carboxylation (Vcmax being optimized at each site. Regarding short-term day-to-day variations, the model performance was good for gross primary production (GPP (r2 =  0.76; Nash–Sutcliffe modeling efficiency, MEF  =  0.76 and ecosystem respiration (ER, r2 =  0.78, MEF  =  0.75, with lesser accuracy for latent heat fluxes (LE, r2 =  0.42, MEF  =  0.14 and and net ecosystem CO2 exchange (NEE, r2 =  0.38, MEF  =  0.26. Seasonal variations in GPP, ER, NEE, and energy fluxes on monthly scales showed moderate to high r2 values (0.57–0.86. For spatial across-site gradients of annual mean GPP, ER, NEE, and LE, r2 values of 0.93, 0.89, 0.27, and 0.71 were achieved, respectively. Water table (WT variation was not well predicted (r2 < 0.1, likely due to the uncertain water input to the peat from surrounding areas. However, the poor performance of WT simulation did not greatly affect predictions of ER and NEE. We found a significant relationship between optimized Vcmax and latitude (temperature, which better reflects the spatial gradients of annual NEE than using an average Vcmax value.

  12. Seasonal effects of irrigation on land-atmosphere latent heat, sensible heat and carbon fluxes in semi-arid basin

    Science.gov (United States)

    Xie, Zhenghui; Zeng, Yujin

    2017-04-01

    Irrigation, which constitutes 70% of the total amount of fresh water consumed by the human population, is significantly impacting the land-atmosphere fluxes. In this study, using the improved Community Land Model version 4.5 (CLM 4.5) with an active crop model, two high resolution ( 1 km) simulations investigating the effects of irrigation on Latent Heat (LH), Sensible Heat (SH) and Carbon Fluxes (or net ecosystem exchange, NEE) from land to atmosphere on the Heihe River Basin in northwestern China were conducted using a high-quality irrigation dataset compiled from 1981 to 2013. The model output and measurements from remote sensing demonstrated the capacity and viability of the developed models to reproduce ecological and hydrological processes. The results revealed the effects of irrigation on LH and SH are strongest during summer with a LH increase of 100 W/m2 and a SH decrease of 60 W/m2 over intensely irrigated areas. However, the reactions are much weaker during spring and autumn when there is much less irrigation. When the irrigation rate below 5 mm/day, the LH generally increases, whereas the SH decreases with growing irrigation rates. However, when the irrigation threshold is in excess of 5 mm/day, there is no accrued effect of irrigation on the LH and SH. Irrigation produces opposite effects to the NEE during spring and summer. During the spring, irrigation yields more discharged carbon from the land to the atmosphere, increasing the NEE value by 0.4-0.8 gC/m2/day, while the summer irrigation favors crop fixing of carbon from atmospheric CO2, decreasing the NEE value by 0.8 gC/m2/day. The repercussions of irrigation on land-atmosphere fluxes are not solely linked to the irrigation amount, and other parameters (especially the temperature) also control the effects of irrigation on LH, SH and NEE. The study indicates that how a land surface model with high spatial resolution can represent crop growing and its effects over basin scale.

  13. Sensitivity of temperate desert steppe carbon exchange to seasonal droughts and precipitation variations in Inner Mongolia, China.

    Science.gov (United States)

    Yang, Fulin; Zhou, Guangsheng

    2013-01-01

    Arid grassland ecosystems have significant interannual variation in carbon exchange; however, it is unclear how environmental factors influence carbon exchange in different hydrological years. In this study, the eddy covariance technique was used to investigate the seasonal and interannual variability of CO₂ flux over a temperate desert steppe in Inner Mongolia, China from 2008 to 2010. The amounts and times of precipitation varied significantly throughout the study period. The precipitation in 2009 (186.4 mm) was close to the long-term average (183.9±47.6 mm), while the precipitation in 2008 (136.3 mm) and 2010 (141.3 mm) was approximately a quarter below the long-term average. The temperate desert steppe showed carbon neutrality for atmospheric CO₂ throughout the study period, with a net ecosystem carbon dioxide exchange (NEE) of -7.2, -22.9, and 26.0 g C m⁻² yr⁻¹ in 2008, 2009, and 2010, not significantly different from zero. The ecosystem gained more carbon in 2009 compared to other two relatively dry years, while there was significant difference in carbon uptake between 2008 and 2010, although both years recorded similar annual precipitation. The results suggest that summer precipitation is a key factor determining annual NEE. The apparent quantum yield and saturation value of NEE (NEE(sat)) and the temperature sensitivity coefficient of ecosystem respiration (R(eco)) exhibited significant variations. The values of NEE(sat) were -2.6, -2.9, and -1.4 µmol CO₂ m⁻² s⁻¹ in 2008, 2009, and 2010, respectively. Drought suppressed both the gross primary production (GPP) and R(eco), and the drought sensitivity of GPP was greater than that of R(eco). The soil water content sensitivity of GPP was high during the dry year of 2008 with limited soil moisture availability. Our results suggest the carbon balance of this temperate desert steppe was not only sensitive to total annual precipitation, but also to its seasonal distribution.

  14. Processo de inclusão na escola regular: panorama de percepções

    Directory of Open Access Journals (Sweden)

    Anselmo Barce Furini

    2011-11-01

    Full Text Available O presente artigo de pesquisa tem como finalidade apresentar algumas considerações sobre o processo de inclusão de crianças com necessidades educativas especiais (NEE no ensino regular a partir da pesquisa de mestrado que se realizou na PUCRS entre 2004 e 2006. O estudo intitulado processo de inclusão: a criança com necessidade educativa especial e os envolvidos, objetivou averiguar as percepções dos envolvidos no processo de inclusão a respeito deste e das crianças com NEE no contexto das Séries Iniciais do Ensino Fundamental. Foi um estudo qualitativo, com abordagem do tipo etnográfico. Os resultados mostram que a inclusão de alunos com NEE na escola regular está fomentando mudanças na estrutura pedagógica, no currículo, no planejamento diário e no espaço físico. Reconheceu-se ainda, os aspectos que dificultam e facilitam o processo de inclusão. Identificou-se que as famílias aprovam a inclusão dos filhos na escola regular e que os educadores pensam que o processo de inclusão é algo novo e exige mudanças na escola e no olhar às diferenças. Observou-se que os comportamentos das crianças com NEE variaram da distração ao empenho à realização das atividades pedagógicas e a comunicação predominante foi a verbal e a relação destas com o grupo oscilou entre conflitos e momentos de bom relacionamento. As crianças com NEE pesquisadas evidenciaram sentir-se bem na escola regular, comunicar-se e relacionar-se com o grupo, parecendo incluídas. O processo de inclusão não é algo pronto, mas deve ser construído em cada contexto pelos participantes.Palavras-chave: Inclusão. Crianças com Necessidades Educativas Especiais. Família. Educadores. Sociedade. Diferenças.

  15. Ten-year variability in fluxes, meteorology, and environmental conditions at a Colorado subalpine forest site

    Science.gov (United States)

    Burns, S. P.; Turnipseed, A.; Bowling, D. R.; Hu, J.; Monson, R. K.

    2009-12-01

    Changing meteorological and environmental conditions affect fluxes; model analysis has shown that environmental variability directly accounts for about half the interannual variability in net ecosystem exchange (NEE) of CO2 whereas the other 50% is due to biotic responses to these changing variables (Richardson et al. 2007). In our study, ten years (1998-2008) of turbulent flux measurements of heat, water vapor, and CO2 at the Niwot Ridge AmeriFlux site (Monson et al. 2002) are examined with respect to meteorological conditions (atmospheric temperature, stability, precipitation, and cloudiness) as well as changes in environmental conditions, such as snow depth and soil moisture. The typical yearly cycle and an estimate of the magnitude of year-to-year variability in the diurnal fluxes and other variables for a high-elevation subalpine forest ecosystem are presented. Wintertime ecosystem respiration has an average 30-min NEE of 0.62 μmol m-2 s-1 with an interannual range between 0.5-1 μmol m-2 s-1. Uptake of CO2 in late summer has an average NEE of -0.71 μmol m-2 s-1 with an interannual range between -0.1 to -1.5 μmol m-2 s-1. Previous studies at the Niwot Ridge AmeriFlux site have described the importance of photosynthetic photon flux density (PPFD) (Monson et al. 2002) and also growing season length (Hu et al. 2009) on NEE. Water isotope ratios analyzed by Hu et al. (2009) have shown that trees at the site primarily rely on water from snowmelt to sustain them throughout the summer; combining this result with the SIPNET model, Hu et al. conclude that there is a limited connection between summer precipitation and the cumulative annual gross primary production (GPP). We have tested this conclusion more explicitly by examining the response of NEE to specific precipitation events and the effect of extended dry periods on the diel cycle of the fluxes, CO2 mole fraction, sap flow, and other meteorological and soil variables. Additionally, we examine the connection

  16. Desenvolvimento pós-seminal de espécies de Poaceae (Poales Post-seminal development of Poaceae species (Poales

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    Adriana Tiemi Nakamura

    2009-03-01

    Full Text Available O presente estudo objetivou verificar a existência de um padrão do desenvolvimento pós-seminal em Poaceae. Para tanto, foram estudadas as seguintes espécies: Olyra humilis Nees (Bambusoideae; Axonopus aureus P. Beauv. e Paspalum polyphyllum Nees ex Trin. (Panicoideae; Chloris elata Nees e Eragrostis solida Desv. (Chloridoideae. Procurou-se também comparar as estruturas da plântula de Poaceae com as demais monocotiledôneas. As espécies estudadas são plantas perenes, rizomatosas, cespitosas e apresentam cariopses de tamanhos diferentes. Apresentam sementes albuminosas; embrião lateral, diferenciado, com raiz endógena (adventícia; cotilédone dividido em hiperfilo (escutelo, bainha reduzida e hipofilo (coleóptilo; coleorriza (raiz primária reduzida e mesocótilo (eixo localizado entre o escutelo e coleóptilo. A presença de epiblasto (folha embrionária foi observada em Olyra humilis, Chloris elata e Eragrostis solida. O desenvolvimento pós-seminal é semelhante nas espécies estudadas e forma um padrão em Poaceae. Primeiramente, observa-se a emissão da coleorriza, que cresce no sentido geotrópico positivo, seguida do coleóptilo e plúmula que crescem em sentido contrário, a partir do desenvolvimento do mesocótilo. As primeiras folhas são semelhantes às folhas definitivas (metafilos das espécies, exceto em Olyra humilis, que são modificadas em catafilos e podem ser interpretadas como caráter basal em Bambusoideae. Raiz primária reduzida (coleorriza e hipofilo modificado em coleóptilo são considerados caracteres derivados em Poaceae, quando comparados com as demais monocotiledôneas.This work has aimed to verify the existence of a pattern of the post-seminal development in Poaceae. Thus, Olyra humilis Nees (Bambusoideae; Axonopus aureus P. Beauv. e Paspalum polyphyllum Nees ex Trin. (Panicoideae; Chloris elata Nees e Eragrostis solida Desv. (Chloridoideae have been studied. Besides, it was compared the structures of

  17. A comparison of different inverse carbon flux estimation approaches for application on a regional domain

    Science.gov (United States)

    Tolk, L. F.; Dolman, A. J.; Meesters, A. G. C. A.; Peters, W.

    2011-10-01

    We have implemented six different inverse carbon flux estimation methods in a regional carbon dioxide (CO2) flux modeling system for the Netherlands. The system consists of the Regional Atmospheric Mesoscale Modeling System (RAMS) coupled to a simple carbon flux scheme which is run in a coupled fashion on relatively high resolution (10 km). Using an Ensemble Kalman filter approach we try to estimate spatiotemporal carbon exchange patterns from atmospheric CO2 mole fractions over the Netherlands for a two week period in spring 2008. The focus of this work is the different strategies that can be employed to turn first-guess fluxes into optimal ones, which is known as a fundamental design choice that can affect the outcome of an inversion significantly. Different state-of-the-art approaches with respect to the estimation of net ecosystem exchange (NEE) are compared quantitatively: (1) where NEE is scaled by one linear multiplication factor per land-use type, (2) where the same is done for photosynthesis (GPP) and respiration (R) separately with varying assumptions for the correlation structure, (3) where we solve for those same multiplication factors but now for each grid box, and (4) where we optimize physical parameters of the underlying biosphere model for each land-use type. The pattern to be retrieved in this pseudo-data experiment is different in nearly all aspects from the first-guess fluxes, including the structure of the underlying flux model, reflecting the difference between the modeled fluxes and the fluxes in the real world. This makes our study a stringent test of the performance of these methods, which are currently widely used in carbon cycle inverse studies. Our results show that all methods struggle to retrieve the spatiotemporal NEE distribution, and none of them succeeds in finding accurate domain averaged NEE with correct spatial and temporal behavior. The main cause is the difference between the structures of the first-guess and true CO2 flux

  18. Análise da necessidade de preparação pedagógica de professores de cursos de licenciatura para inclusão de alunos com necessidades educacionais especiais Analysis of the need for a bachelor degree professors' pedagogical preparation to deal with the special need students' inclusion

    Directory of Open Access Journals (Sweden)

    Célia Regina Vitalino

    2007-12-01

    Full Text Available A inclusão de alunos com necessidades educacionais especiais (NEE requer professores capazes de promover sua aprendizagem e participação. No entanto, a maioria dos professores atuantes nos diversos níveis de ensino se encontra despreparada para assumir esta responsabilidade. Visando contribuir para melhorar esta situação, este estudo teve como objetivos: 1 verificar se os professores dos cursos de licenciatura da Universidade Estadual de Londrina (UEL têm conhecimento suficiente para incluir alunos com NEE em suas atividades acadêmicas; 2 identificar se estes professores percebem a necessidade de participar de um programa de preparação pedagógica para incluir alunos com NEE e de que maneira deveria dar-se esta preparação. Em vista dos objetivos propostos foi realizada uma pesquisa descritiva. Participaram desta pesquisa 178 professores atuantes em 13 cursos de licenciatura da Universidade Estadual de Londrina. Os dados foram coletados por meio de um questionário contendo 17 questões objetivas. Os resultados evidenciaram que 84% dos participantes consideraram que não tinham conhecimento suficiente para incluir alunos com NEE. 63% dos participantes se interessaram em participar de um programa de formação para inclusão de alunos com NEE e indicaram os temas a serem abordados, bem como a metodologia de ensino a ser utilizada. Consideramos que os resultados obtidos possibilitaram a organização de diretrizes para o planejamento de um programa de formação pedagógica junto a professores de cursos de licenciatura para inclusão de alunos com NEE.The inclusion of students with special educational needs requires teachers capable of promoting their learning and participation. However, most active teachers and professors at various teaching levels are not prepared to take that responsibility. Looking for a way to contribute, the present study aimed to: 1 verify whether the professors who teach undergraduates of teacher preparation

  19. Carbon and Water Fluxes of Crops Exposed to the Sequence of Naturally Occurring Heat Stress, Drought and Freezing

    Science.gov (United States)

    Joo, E.; Miller, J. N.; Bernacchi, C.

    2015-12-01

    As a consequence of global climate change the occurrence of extreme weather events (heat waves, cold spells, drought, etc) are predicted to become more frequent and/or intense, which will likely have a large impact on crop production. In the winter of 2013/2014 several polar vortexes were experienced in Illinois, US, resulting in periods of extreme low temperatures between -20°C and -35°C. Prior to the extreme cold winter of 2013/2014 the region experienced drought over a hot summer in 2012. Four established fields of three perennial biofuel crops (Miscanthus x giganteus, Panicum virgatum L., and a mixture of native prairie species) and Zea mays/Glycine max agroecosystem have been studied since 2009 in order to investigate the effect of climate change and land-use change on carbon and water fluxes using the eddy covariance technique, as well as biomass production of these species. The combined effect of the heat and drought stress in 2012 resulted in severe water deficit of all species (up to -360 mm for miscanthus), which resulted in reduced net ecosystem exchange (NEE) during the drought for all species other than miscanthus. In the following year, during the recovery of these species from drought, miscanthus showed decreased NEE but the other species did not appear to be negatively influenced. As a consequence of the environmental stresses (heat and drought stress followed by extreme freezing), the water and carbon exchanges (such as ET, NEE, GPP, Reco) as well as growth parameters (LAI, biomass production) are shown to vary based on the stress tolerance of these species.

  20. The potential of carbonyl sulfide as a proxy for gross primary production at flux tower sites

    Science.gov (United States)

    Blonquist, J. Mark, Jr.

    Seasonal dynamics of atmospheric carbonyl sulfide (OCS) at regional and continental scales and plant OCS exchange at the leaf level have shown a close relationship with those for CO2. CO2 has both sinks and sources within terrestrial ecosystems, but the primary terrestrial exchange for OCS is thought to be leaf uptake, suggesting potential for OCS uptake as a proxy for gross primary production (GPP). The utility of OCS uptake as a GPP proxy in micrometeorological studies of biosphere-atmosphere CO2 exchange was explored by applying theoretical concepts from earlier OCS studies to estimate GPP. Measured net ecosystem exchange (NEE) was partitioned using the ratio of measured vertical mole fraction gradients of OCS and CO2. At the Harvard Forest AmeriFlux site, measured CO2 and OCS vertical gradients were correlated, and were related to NEE and GPP, respectively. Estimates of GPP from OCS-based NEE partitioning were similar to those from established regression techniques, providing evidence that OCS uptake can potentially serve as a GPP proxy. Measured vertical CO 2 mole fraction gradients at five other AmeriFlux sites were used to project anticipated vertical OCS mole fraction gradients to provide indication of potential OCS signal magnitudes at sites where no OCS measurements were made. Projected OCS gradients at sites with short canopies were greater than those in forests, including measured OCS gradients at Harvard Forest, indicating greater potential for OCS uptake as a GPP proxy at these sites. This exploratory study suggests that continued investigation of linkages between OCS and GPP is warranted.

  1. Lifespan Development of the Human Brain Revealed by Large-Scale Network Eigen-Entropy

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    Yiming Fan

    2017-09-01

    Full Text Available Imaging connectomics based on graph theory has become an effective and unique methodological framework for studying functional connectivity patterns of the developing and aging brain. Normal brain development is characterized by continuous and significant network evolution through infancy, childhood, and adolescence, following specific maturational patterns. Normal aging is related to some resting state brain networks disruption, which are associated with certain cognitive decline. It is a big challenge to design an integral metric to track connectome evolution patterns across the lifespan, which is to understand the principles of network organization in the human brain. In this study, we first defined a brain network eigen-entropy (NEE based on the energy probability (EP of each brain node. Next, we used the NEE to characterize the lifespan orderness trajectory of the whole-brain functional connectivity of 173 healthy individuals ranging in age from 7 to 85 years. The results revealed that during the lifespan, the whole-brain NEE exhibited a significant non-linear decrease and that the EP distribution shifted from concentration to wide dispersion, implying orderness enhancement of functional connectome over age. Furthermore, brain regions with significant EP changes from the flourishing (7–20 years to the youth period (23–38 years were mainly located in the right prefrontal cortex and basal ganglia, and were involved in emotion regulation and executive function in coordination with the action of the sensory system, implying that self-awareness and voluntary control performance significantly changed during neurodevelopment. However, the changes from the youth period to middle age (40–59 years were located in the mesial temporal lobe and caudate, which are associated with long-term memory, implying that the memory of the human brain begins to decline with age during this period. Overall, the findings suggested that the human connectome

  2. Ecosystem-scale fluxes in seminatural Pyrenean grasslands: role of annual dynamics of plant functional types

    Science.gov (United States)

    Altimir, Nuria; Ibañez, Mercedes; Elbers, Jan; Rota, Cristina; Arias, Claudia; Carrara, Arnaud; Nogues, Salvador; Sebastia, Maria-Teresa

    2013-04-01

    The net ecosystem exchange (NEE) and the annual C balance of a site are in general modulated by light, temperature and availability of water and other resources to the plants. In grasslands, NEE is expected to depend strongly on the vegetation with a relationship that can be summarized by the above-ground biomass, its amount and dynamics. Any factor controlling the amount of green biomass is expected to have a strong impact on the short-term NEE, such as amount of solar radiation, water availability and grazing pressure. These controls are modulated differently depending on the plant functional type enduring them. Furthermore, as different guilds follow different functional strategies for optimization of the resources, they also present different patterns of change in their capacities such as photosynthetic fixation, belowground C allocation, and C loss via respiration. We examined these relationships at several semi-natural pastures to determine how the seasonal distribution of plant functional types is detected in the short-term ecosystem exchange and what role it plays. We have looked into these patterns to determine the general variation of key processes and whether different temporal patterns arise between different guilds. The study sites are in the Pyrenees, on the mountain pastures of La Bertolina, Alinyà, and Castellar at 1300, 1700, 1900 m a.s.l. respectively. We performed ecosystem-scale flux measurements by means of micrometeorologial stations combined with a thorough description of the vegetation including below- and above-ground biomass and leaf area as well as monitoring of natural abundance of C isotopes, discriminated by plant functional types. We present here the results of the study.

  3. Effects of simulated drought on the carbon balance of Everglades short-hydroperiod marsh.

    Science.gov (United States)

    Malone, Sparkle L; Starr, Gregory; Staudhammer, Christina L; Ryan, Michael G

    2013-08-01

    Hydrology drives the carbon balance of wetlands by controlling the uptake and release of CO2 and CH4 . Longer dry periods in between heavier precipitation events predicted for the Everglades region, may alter the stability of large carbon pools in this wetland's ecosystems. To determine the effects of drought on CO2 fluxes and CH4 emissions, we simulated changes in hydroperiod with three scenarios that differed in the onset rate of drought (gradual, intermediate, and rapid transition into drought) on 18 freshwater wetland monoliths collected from an Everglades short-hydroperiod marsh. Simulated drought, regardless of the onset rate, resulted in higher net CO2 losses net ecosystem exchange (NEE) over the 22-week manipulation. Drought caused extensive vegetation dieback, increased ecosystem respiration (Reco ), and reduced carbon uptake gross ecosystem exchange (GEE). Photosynthetic potential measured by reflective indices (photochemical reflectance index, water index, normalized phaeophytinization index, and the normalized difference vegetation index) indicated that water stress limited GEE and inhibited Reco . As a result of drought-induced dieback, NEE did not offset methane production during periods of inundation. The average ratio of net CH4 to NEE over the study period was 0.06, surpassing the 100-year greenhouse warming compensation point for CH4 (0.04). Drought-induced diebacks of sawgrass (C3 ) led to the establishment of the invasive species torpedograss (C4 ) when water was resupplied. These changes in the structure and function indicate that freshwater marsh ecosystems can become a net source of CO2 and CH4 to the atmosphere, even following an extended drought. Future changes in precipitation patterns and drought occurrence/duration can change the carbon storage capacity of freshwater marshes from sinks to sources of carbon to the atmosphere. Therefore, climate change will impact the carbon storage capacity of freshwater marshes by influencing water

  4. Environmental and Physiographic Controls on Inter-Growing Season Variability of Carbon Dioxide and Water Vapour Fluxes in a Minerotrophic Fen

    Science.gov (United States)

    van der Kamp, G.; Sonnentag, O.; Chen, J. M.; Barr, A.; Hedstrom, N.; Granger, R.

    2008-12-01

    The interaction of fens with groundwater is spatially and temporally highly variable in response to meteorological conditions, resulting in frequent changes of groundwater fluxes in both vertical and lateral directions (flow reversals) across the mineral soil-peat boundary. However, despite the importance of the topographic and hydrogeological setting of fens, no study has been reported in the literature that explores a fen's atmospheric CO2 and energy flux densities under contrasting meteorological conditions in response to its physiographic setting. In our contribution we report four years of growing season eddy covariance and supporting measurements from the Canada Fluxnet-BERMS fen (formerly BOREAS southern peatland) in Saskatchewan, Canada. We first analyze hydrological data along two piezometer transects across the mineral soil-peat boundary with the objective of assessing changes in water table configuration and thus hydraulic gradients, indicating flow reversals, in response to dry and wet meteorological conditions. Next we quantify and compare growing season totals and diurnal and daily variations in evapotranspiration (ET) and net ecosystem exchange (NEE) and its component fluxes gross ecosystem productivity (GPP) and terrestrial ecosystem respiration (TER) to identify their controls with a major focus on water table depth. While ET growing season totals were similar (~ 310 mm) under dry and wet meteorological conditions, the CO2 sink- source strength of Sandhill fen varied substantially from carbon neutral (NEE = -2 [+-7] g C m-2 per growing season) under dry meteorological condition (2003) to a moderate CO2- sink with NEE ranging between 157 [+- 10] and 190 [+- 11] g C m-2 per growing season under wet meteorological conditions (2004, 2005, and 2006). Using a process-oriented ecosystem model, BEPS-TerrainLab, we investigate how different canopy components at Sandhill contribute to total ET and GPP, and thus water use efficiency, under dry and wet

  5. Greenhouse gas fluxes in mountain grassland differing in land use

    Science.gov (United States)

    Ladreiter-Knauss, Thomas; Schmitt, Michael; Butterbach-Bahl, Klaus; Kienzl, Sandra; Ingrisch, Johannes; Hasibeder, Roland; Bahn, Michael

    2013-04-01

    Mountain grassland covers large areas, thus influences the global greenhouse gas (GHG) balance and is strongly affected by changes in land use. Effects of such changes on the GHG-balance have so far not been well documented. As a contribution to the EU-project GHG Europe we are studying the net ecosystem exchange (NEE) of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) on a mountain meadow, an adjacent and an abandoned pasture at 1820-1970m a.s.l. in the Austrian Central Alps. The GHG balance is estimated from manual and auto-chamber measurements, combined with already published CO2-NEE over almost a decade. Winter CO2-fluxes, primarily soil respiration underneath the snowpack, are estimated with solid state CO2-sensors using a validated diffusion model. We found that abandon the management decreases the NEE of CO2 while its component, soil respiration (Rs), increases. The decrease is explained by differences in leaf area index, biomass and leaf-area-independent changes that were likely related to photosynthetic physiology. The increase in Rs can be explained by higher belowground carbon input due to missing grazing or mowing. The abandoned pasture showed the highest uptake rates of CH4 and a slight uptake of N2O, possibly due to better soil aeration. Spring freeze-thaw events caused slight CH4 emissions in the managed grassland. The meadow and pasture had just low emission rates of N2O even at freeze-thaw cycles and organic fertilization. These results suggest that in mountain grassland the main contributor to the GHG balance are CO2 fluxes that can largely be influenced by land use changes.

  6. Nanoelectrochemical Immunosensors for Protein Detection

    Science.gov (United States)

    Carpentiero, Alessandro; de Leo, Manuela; Garcia Romero, Ivan; Pozzi Mucelli, Stefano; Reuther, Freimut; Stanta, Giorgio; Tormen, Massimo; Ugo, Paolo; Zamuner, Martina

    Nanoelectrochemical immunosensors fabricated by templated electrodeposition of gold nanoelectrodes inside the pores of polycarbonate (PC) track-etched membranes, followed by the immobilization of the biorecognition elements on the surrounding PC, have proven high sensitivity and specificity for protein detection. The signal transduction scheme involves a suitable redox mediator added to the sample solution to shuttle electrons from the gold nanoelectrodes to the biorecognition layer, both elements being in strict spatial proximity. Highly improved signal-to-background current ratio, which are peculiar of NEEs with respect to other electrochemical transducers, can be exploited in this way. Two detection schemes were tested: one based on the direct immobilization of the target protein on the PC of the NEE (approach A) and the other based on the immobilisation on PC of an antibody to capture the target protein (approach B). The biorecognition process was completed by adding a primary antibody and a secondary antibody with horse radish peroxidase (HRP) as enzyme label; methylene blue was the redox mediator added to the electrolyte solution. Typical target analytes were single chain fragment variable proteins, for approach A, and trastuzumab (also known as Herceptin®), for approach B. NEE-based capture sensors were tested successfully to detect small amounts of the receptor protein HER2 in biological samples. Finally, motivated by the target of a better control of the geometrical characteristics of ensembles of nanoelectrodes (size, density, geometrical arrangement, and degree of recession), and by the positive results obtained with track-etch membranes of PC from the standpoint of protein immobilization, we demonstrated the fabrication of nanobiosensors by patterning ordered arrays of nanoelectrodes (NEAs) by electron beam lithography (EBL) on polycarbonate. EBL results perfectly suitable for the top-down fabrication of arrays of nanobiosensors on thin PC films

  7. Carbon dioxide fluxes from contrasting ecosystems in the Sudanian Savanna in West Africa.

    Science.gov (United States)

    Quansah, Emmanuel; Mauder, Matthias; Balogun, Ahmed A; Amekudzi, Leonard K; Hingerl, Luitpold; Bliefernicht, Jan; Kunstmann, Harald

    2015-12-01

    The terrestrial land surface in West Africa is made up of several types of savanna ecosystems differing in land use changes which modulate gas exchanges between their vegetation and the overlying atmosphere. This study compares diurnal and seasonal estimates of CO2 fluxes from three contrasting ecosystems, a grassland, a mixture of fallow and cropland, and nature reserve in the Sudanian Savanna and relate them to water availability and land use characteristics. Over the study period, and for the three study sites, low soil moisture availability, high vapour pressure deficit and low ecosystem respiration were prevalent during the dry season (November to March), but the contrary occurred during the rainy season (May to October). Carbon uptake predominantly took place in the rainy season, while net carbon efflux occurred in the dry season as well as the dry to wet and wet to dry transition periods (AM and ND) respectively. Carbon uptake decreased in the order of the nature reserve, a mixture of fallow and cropland, and grassland. Only the nature reserve ecosystem at the Nazinga Park served as a net sink of CO2, mostly by virtue of a several times larger carbon uptake and ecosystem water use efficiency during the rainy season than at the other sites. These differences were influenced by albedo, LAI, EWUE, PPFD and climatology during the period of study. These results suggest that land use characteristics affect plant physiological processes that lead to flux exchanges over the Sudanian Savanna ecosystems. It affects the diurnal, seasonal and annual changes in NEE and its composite signals, GPP and RE. GPP and NEE were generally related as NEE scaled with photosynthesis with higher CO2 assimilation leading to higher GPP. However, CO2 effluxes over the study period suggest that besides biomass regrowth, other processes, most likely from the soil might have also contributed to the enhancement of ecosystem respiration.

  8. Elevated carbon dioxide alters impacts of precipitation pulses on ecosystem photosynthesis and respiration in a semi-arid grassland.

    Science.gov (United States)

    Bachman, Sarah; Heisler-White, Jana L; Pendall, Elise; Williams, David G; Morgan, Jack A; Newcomb, Joanne

    2010-03-01

    Predicting net C balance under future global change scenarios requires a comprehensive understanding of how ecosystem photosynthesis (gross primary production; GPP) and respiration (Re) respond to elevated atmospheric [CO(2)] and altered water availability. We measured net ecosystem exchange of CO(2) (NEE), GPP and Re under ambient and elevated [CO(2)] in a northern mixed-grass prairie (Wyoming, USA) during dry intervals and in response to simulated precipitation pulse events. Elevated [CO(2)] resulted in higher rates of both GPP and Re across the 2006 growing season, and the balance of these two fluxes (NEE) accounted for cumulative growing season C uptake (-14.4 +/- 8.3 g C m(-2)). Despite lower GPP and Re, experimental plots under ambient [CO(2)] had greater cumulative uptake (-36.2 +/- 8.2 g C m(-2)) than plots under elevated [CO(2)]. Non-irrigated control plots received 50% of average precipitation during the drought of 2006, and had near-zero NEE (1.9 +/- 6.4 g C m(-2)) for the growing season. Elevated [CO(2)] extended the magnitude and duration of pulse-related increases in GPP, resulting in a significant [CO(2)] treatment by pulse day interaction, demonstrating the potential for elevated [CO(2)] to increase the capacity of this ecosystem to respond to late-season precipitation. However, stimulation of Re throughout the growing season under elevated [CO(2)] reduced net C uptake compared to plots under ambient [CO(2)]. These results indicate that although elevated [CO(2)] stimulates gross rates of ecosystem C fluxes, it does not necessarily enhance net C uptake, and that C cycle responses in semi-arid grasslands are likely to be more sensitive to changes in precipitation than atmospheric [CO(2)].

  9. Carbon exchange between the atmosphere and subtropical forested cypress and pine wetlands

    Science.gov (United States)

    Shoemaker, W. B.; Barr, J. G.; Botkin, D. B.; Graham, S. L.

    2014-11-01

    Carbon dioxide exchange between the atmosphere and forested subtropical wetlands is largely unknown. Here we report a first step in characterizing this atmospheric-ecosystem carbon (C) exchange, for cypress strands and pine forests in the Greater Everglades of Florida as measured with eddy covariance methods at three locations (Cypress Swamp, Dwarf Cypress and Pine Upland) for one year. Links between water and C cycles are examined at these three sites, and methane emission measured only at the Dwarf Cypress site. Each forested wetland showed net C uptake (retained in the soil and biomass or transported laterally via overland flow) from the atmosphere monthly and annually. Net ecosystem exchange (NEE) of carbon dioxide (CO2) (difference between photosynthesis and respiration, with negative values representing net ecosystem uptake) was greatest at the Cypress Swamp (-1000 g C m-2 year-1), moderate at the Pine Upland (-900 g C m-2 year-1), and least at the Dwarf Cypress (-500 g C m-2 year-1). Methane emission was a negligible part of the C (12 g C m-2 year-1) budget when compared to NEE. However, methane (CH4) production was considerable in terms of global warming potential, as about 20 g CH4 emitted per m2 year was equivalent to about 500 g CO2 emitted per m2 year}. Changes in NEE were clearly a function of seasonality in solar insolation, air temperature and water availability from rainfall. We also note that changes in the satellite-derived enhanced-vegetation index (EVI) served as a useful surrogate for changes in net and gross atmospheric-ecosystem C exchange at these forested wetland sites.

  10. Typhoons exert significant but differential impacts on net ecosystem carbon exchange of subtropical mangrove forests in China

    Science.gov (United States)

    Chen, H.; Lu, W.; Yan, G.; Yang, S.; Lin, G.

    2014-10-01

    Typhoons are very unpredictable natural disturbances to subtropical mangrove forests in Asian countries, but little information is available on how these disturbances affect ecosystem level carbon dioxide (CO2) exchange of mangrove wetlands. In this study, we examined short-term effect of frequent strong typhoons on defoliation and net ecosystem CO2 exchange (NEE) of subtropical mangroves, and also synthesized 19 typhoons during a 4-year period between 2009 and 2012 to further investigate the regulation mechanisms of typhoons on ecosystem carbon and water fluxes following typhoon disturbances. Strong wind and intensive rainfall caused defoliation and local cooling effect during the typhoon season. Daily total NEE values decreased by 26-50% following some typhoons (e.g., W28-Nockten, W35-Molave and W35-Lio-Fan), but significantly increased (43-131%) following typhoon W23-Babj and W38-Megi. The magnitudes and trends of daily NEE responses were highly variable following different typhoons, which were determined by the balance between the variances of gross ecosystem production (GEP) and ecosystem respiration (RE). Furthermore, results from our synthesis indicated that the landfall time of typhoon, wind speed and rainfall were the most important factors controlling the CO2 fluxes following typhoon events. These findings indicate that different types of typhoon disturbances can exert very different effects on CO2 fluxes of mangrove ecosystems and that typhoon will likely have larger impacts on carbon cycle processes in subtropical mangrove ecosystems as the intensity and frequency of typhoons are predicted to increase under future global climate change scenarios.

  11. Effect of smoke and clouds on the transmissivity of photosynthetically active radiation inside the canopy

    Science.gov (United States)

    Yamasoe, M. A.; von Randow, C.; Manzi, A. O.; Schafer, J. S.; Eck, T. F.; Holben, B. N.

    2006-05-01

    Biomass burning activities emit high concentrations of aerosol particles to the atmosphere. Such particles can interact with solar radiation, decreasing the amount of light reaching the surface and increasing the fraction of diffuse radiation through scattering processes, and thus has implications for photosynthesis within plant canopies. This work reports results from photosynthetically active radiation (PAR) and aerosol optical depth (AOD) measurements conducted simultaneously at Reserva Biológica do Jaru (Rondonia State, Brazil) during LBA/SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia/ Smoke, Aerosols, Clouds, Rainfall, and Climate) and RaCCI (Radiation, Cloud, and Climate Interactions in the Amazon during the Dry-to-Wet Transition Season) field experiments from 15 September to 15 November 2002. AOD values were retrieved from an AERONET (Aerosol Robotic Network) radiometer, MODIS (Moderate Resolution Spectroradiometer) and a portable sunphotometer from the United States Department of Agriculture - Forest Service. Significant reduction of PAR irradiance at the top of the canopy was observed due to the smoke aerosol particles layer. This radiation reduction affected turbulent fluxes of sensible and latent heats. The increase of AOD also enhanced the transmission of PAR inside the canopy. As a consequence, the availability of diffuse radiation was enhanced due to light scattering by the aerosol particles. A complex relationship was identified between light availability inside the canopy and net ecosystem exchange (NEE). The results showed that the increase of aerosol optical depth corresponded to an increase of CO2 uptake by the vegetation. However, for even higher AOD values, the corresponding NEE was lower than for intermediate values. As expected, water vapor pressure deficit (VPD), retrieved at 28m height inside the canopy, can also affect photosynthesis. A decrease in NEE was observed as VPD increased. Further studies are needed to better

  12. Seasonal and inter-annual variability in 13C composition of ecosystem carbon fluxes in the U.S. Southern Great Plains

    Energy Technology Data Exchange (ETDEWEB)

    Torn, M.S.; Biraud, S.; Still, C.J.; Riley, W.J.; Berry, J.A.

    2010-09-22

    The {delta}{sup 13}C signature of terrestrial carbon fluxes ({delta}{sub bio}) provides an important constraint for inverse models of CO{sub 2} sources and sinks, insight into vegetation physiology, C{sub 3} and C{sub 4} vegetation productivity, and ecosystem carbon residence times. From 2002-2009, we measured atmospheric CO{sub 2} concentration and {delta}{sup 13}C-CO{sub 2} at four heights (2 to 60 m) in the U.S. Southern Great Plains (SGP) and computed {delta}{sub bio} weekly. This region has a fine-scale mix of crops (primarily C{sub 3} winter wheat) and C{sub 4} pasture grasses. {delta}{sub bio} had a large and consistent seasonal cycle of 6-8{per_thousand}. Ensemble monthly mean {delta}{sub bio} ranged from -25.8 {+-} 0.4{per_thousand} ({+-}SE) in March to -20.1 {+-} 0.4{per_thousand} in July. Thus, C{sub 3} vegetation contributed about 80% of ecosystem fluxes in winter-spring and 50% in summer-fall. In contrast, prairie-soil {delta}{sub 13}C values were about -15{per_thousand}, indicating that historically the region was dominated by C{sub 4} vegetation and had more positive {delta}{sub bio} values. Based on a land-surface model, isofluxes ({delta}{sub bio} x NEE) in this region have large seasonal amplitude because {delta}{sub bio} and net ecosystem exchange (NEE) covary. Interannual variability in isoflux was driven by variability in NEE. The large seasonal amplitude in {delta}{sub bio} and isoflux imply that carbon inverse analyses require accurate estimates of land cover and temporally resolved {sup 13}CO{sub 2} and CO{sub 2} fluxes.

  13. Long-term observations of CO2 exchange over agricultural crops in two regional climates of Southwest Germany

    Science.gov (United States)

    Poyda, Arne; Wizemann, Hans-Dieter; Ingwersen, Joachim; Wulfmeyer, Volker; Streck, Thilo

    2017-04-01

    The impact of agricultural land use on soil organic carbon (SOC) dynamics has been widely studied in the past few decades, particularly in context of the SOC forcing or mitigation potential of global climate change. Grassland utilization can increase or maintain SOC stocks. Arable cropping tends to decrease SOC stocks, at least for some time after land use change (SMITH, 2008). In the long run, it can be assumed that SOC reaches a steady state where the production of roots and aboveground crop residues and possibly organic fertilization level out soil respiration. To study the effects of crop type, year and regional site conditions on CO2 exchange and C budgets of arable cropping systems in Southwest Germany, eddy covariance measurements were conducted on a total of six sites in the two climatically contrasting regions of Kraichgau and Swabian Alb since 2009. Main crops were winter wheat, silage maize and winter rapeseed but also winter barley, summer barley and spelt were cultivated on the Swabian Alb sites. Cover crops were grown between winter and summer crops on all sites. Net ecosystem exchange (NEE) data were gap-filled following REICHSTEIN et al. (2005) and partitioned into ecosystem respiration (RECO) and gross primary production (GPP) using seasonally differing temperature response functions of nighttime NEE. Furthermore, different approaches for filling long data gaps of several months in winter were evaluated. Considering C inputs by organic fertilizers and C removals by harvest, C budgets were calculated per site and year. First results indicate that the variability of NEE fluxes between different crops is much higher compared to the variability between different years of a certain crop. However, regional differences in soil and weather conditions significantly influence plant growth dynamics and thus CO2 exchange.

  14. Burnout docente no trabalho com a inclusão de alunos com necessidades educacionais especiais

    Directory of Open Access Journals (Sweden)

    Maria Inês Naujorks

    2012-03-01

    Full Text Available O presente estudo objetiva identificar a incidência do Burnout em professores da rede comum de ensino do município de Três de Maio - RS, que trabalham com alunos com necessidades educacionais especiais - NEE incluídos, provenientes da Escola Especial Helen Keller. Sabe-se que ensinar exige conhecimento, pesquisa, competência profissional e, acima de tudo, querer bem aos educandos, sendo, portanto, uma tarefa extremamente complexa. Percebe-se que essa complexidade tende aumentar à medida que o professor se depara com aquele aluno que “não aprende”, aluno com necessidades educacionais especiais – NEE -, haja vista tal aluno apresentar limitações que dificultam seu processo de aprendizagem. Isto poderia estar levando o docente a se sentir impotente frente às dificuldades do aluno, visto que, inconscientemente, estaria trazendo à tona todo um sofrimento seu, o qual poderia estar vinculado à sua história acadêmica e/ ou de vida. O desejo de entender de forma mais profunda os sentimentos e emoções desse professor, que se diz “tocado” ao lidar com alunos com necessidades educacionais especiais, e a necessidade de compreender sua angústia ao interagir, em âmbito de sala de aula, com o aluno com NEE, é que motiva o desenvolvimento desta pesquisa. O texto pretende propor uma discussão a partir de alguns recortes do referencial teórico construído até o momento, e que apontam para a urgência de estudos que possibilitem resgatar no professor o desejo de continuar buscando seu ideal com prazer...sem sofrimento... sem desistir.Palavras-chave: Burnout. Professor. Alunos com necessidades educacionais especiais.

  15. Drivers of inter-annual variability in Net Ecosystem Exchange in a semi-arid savanna ecosystem, South Africa

    Directory of Open Access Journals (Sweden)

    S. A. Archibald

    2009-02-01

    Full Text Available Inter-annual variability in primary production and ecosystem respiration was explored using eddy-covariance data at a semi-arid savanna site in the Kruger Park, South Africa. New methods of extrapolating night-time respiration to the entire day and filling gaps in eddy-covariance data in semi-arid systems were developed. Net ecosystem exchange (NEE in these systems occurs as pulses associated with rainfall events, a pattern not well-represented in current standard gap-filling procedures developed primarily for temperate flux sites. They furthermore do not take into account the decrease in respiration at high soil temperatures. An artificial neural network (ANN model incorporating these features predicted measured fluxes accurately (MAE 0.42 gC/m2/day, and was able to represent the seasonal patterns of photosynthesis and respiration at the site. The amount of green leaf area (indexed using satellite-derived estimates of fractional interception of photosynthetically active radiation fAPAR, and the timing and magnitude of rainfall events, were the two most important predictors used in the ANN model. These drivers were also identified by multiple linear regressions (MLR, with strong interactive effects. The annual integral of the filled NEE data was found to range from −138 to +155 g C/m2/y over the 5 year eddy covariance measurement period. When applied to a 25 year time series of meteorological data, the ANN model predicts an annual mean NEE of 75(±105 g C/m2/y. The main correlates of this inter-annual variability were found to be variation in the amount of absorbed photosynthetically active radiation (APAR, length of the growing season, and number of days in the year when moisture was available in the soil.

  16. Effect of smoke and clouds on the transmissivity of photosynthetically active radiation inside the canopy

    Directory of Open Access Journals (Sweden)

    M. A. Yamasoe

    2006-01-01

    Full Text Available Biomass burning activities emit high concentrations of aerosol particles to the atmosphere. Such particles can interact with solar radiation, decreasing the amount of light reaching the surface and increasing the fraction of diffuse radiation through scattering processes, and thus has implications for photosynthesis within plant canopies. This work reports results from photosynthetically active radiation (PAR and aerosol optical depth (AOD measurements conducted simultaneously at Reserva Biológica do Jaru (Rondonia State, Brazil during LBA/SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia/ Smoke, Aerosols, Clouds, Rainfall, and Climate and RaCCI (Radiation, Cloud, and Climate Interactions in the Amazon during the Dry-to-Wet Transition Season field experiments from 15 September to 15 November 2002. AOD values were retrieved from an AERONET (Aerosol Robotic Network radiometer, MODIS (Moderate Resolution Spectroradiometer and a portable sunphotometer from the United States Department of Agriculture – Forest Service. Significant reduction of PAR irradiance at the top of the canopy was observed due to the smoke aerosol particles layer. This radiation reduction affected turbulent fluxes of sensible and latent heats. The increase of AOD also enhanced the transmission of PAR inside the canopy. As a consequence, the availability of diffuse radiation was enhanced due to light scattering by the aerosol particles. A complex relationship was identified between light availability inside the canopy and net ecosystem exchange (NEE. The results showed that the increase of aerosol optical depth corresponded to an increase of CO2 uptake by the vegetation. However, for even higher AOD values, the corresponding NEE was lower than for intermediate values. As expected, water vapor pressure deficit (VPD, retrieved at 28m height inside the canopy, can also affect photosynthesis. A decrease in NEE was observed as VPD increased. Further studies are needed

  17. How do land management practices affect net ecosystem CO2 exchange of an invasive plant infestation?

    Science.gov (United States)

    Sonnentag, O.; Detto, M.; Runkle, B.; Kelly, M.; Baldocchi, D. D.

    2009-12-01

    Ecosystem gas and energy exchanges of invasive plant infestations under different land management practices have been subject of few studies and thus little is known. Our goal is to characterize seasonal changes in net ecosystem CO2 exchange (NEE) through the processes of photosynthesis (GEP) and ecosystem respiration (Reco) of a grassland used as pasture yet infested by perennial pepperweed (Lepidium latifolium) in California’s Sacramento-San Joaquin River Delta. We analyze eddy-covariance supported by environmental and canopy-scale hyperspectral reflectance measurements acquired in 2007-2009. Our study covers three summer drought periods with slightly different land management practices. Over the study period the site was subject to year-round grazing, and in 2008 the site was additionally mowed. Specific questions we address are a) how does pepperweed flowering affect GEP, b) does a mowing event affect NEE mainly through GEP or Reco, and c) can the combined effects of phenology and mowing on pepperweed NEE potentially be tracked using routinely applied remote sensing techniques? Preliminary results indicate that pepperweed flowering drastically decreases photosynthetic CO2 uptake due to shading by the dense arrangement of white flowers at the canopy top, causing the infestation to be almost CO2 neutral. In contrast, mowing causes the infestation to act as moderate net CO2 sink, mainly due to increased CO2 uptake during regrowth. We demonstrate that spectral regions other than commonly-used red and near-infrared might be more promising for pepperweed monitoring because of its spectral uniqueness during the flowering phase. Our results have important implications for land-use land-cover (LULC) change studies when biological invasions and their management alter ecosystem structure and functioning but not necessarily the respective LULC class.

  18. Carbon and Water Vapor Fluxes of Different Ecosystems in Oklahoma

    Science.gov (United States)

    Wagle, P.; Gowda, P. H.; Northup, B. K.

    2016-12-01

    Information on exchange of energy, carbon dioxide (CO2), and water vapor (H2O) for major terrestrial ecosystems is vital to quantify carbon and water balances on a large-scale. It is also necessary to develop, test, and improve crop models and satellite-based production efficiency and evapotranspiration (ET) models, and to better understand the potential of terrestrial ecosystems to mitigate rising atmospheric CO2 concentration and climate change. A network (GRL-FLUXNET) of nine eddy flux towers has been established over a diverse range of terrestrial ecosystems, including native and improved perennial grasslands [unburned and grazed tallgrass prairie, burned and grazed tallgrass prairie, and burned Bermuda grass (Cynodon dactylon L.)], grazed and non-grazed winter wheat (Triticum aestivum L.), till and no-till winter wheat and canola (Brassica napus L.), alfalfa (Medicago sativa L.), and soybean (Glycine max L.), at the USDA-ARS, Grazinglands Research Laboratory, El Reno, OK. In this presentation, we quantify and compare net ecosystem CO2 exchange (NEE) and ET between recently burned and grazed tallgrass prairie and burned and non-grazed Bermuda grass pastures, alfalfa, and soybean. Preliminary results show monthly ensembles average NEE reached seasonal peak values of -29, -35, -25, and -20 µmol m-2 s-1 in burned tallgrass prairie pasture, burned Bermuda grass pasture, alfalfa, and soybean, respectively. Similarly, monthly ensembles average ET reached seasonal peak values of 0.22, 0.27, 0.25, 0.28 mm 30-min-1 in burned tallgrass prairie pasture, burned Bermuda grass pasture, alfalfa, and soybean, respectively. Seasonal patterns and daily magnitudes of NEE and ET and their responses to the similar climatic conditions will be further investigated.

  19. Intercomparisons of Prognostic, Diagnostic, and Inversion Modeling Approaches for Estimation of Net Ecosystem Exchange over the Pacific Northwest Region

    Science.gov (United States)

    Turner, D. P.; Jacobson, A. R.; Nemani, R. R.

    2013-12-01

    The recent development of large spatially-explicit datasets for multiple variables relevant to monitoring terrestrial carbon flux offers the opportunity to estimate the terrestrial land flux using several alternative, potentially complimentary, approaches. Here we developed and compared regional estimates of net ecosystem exchange (NEE) over the Pacific Northwest region of the U.S. using three approaches. In the prognostic modeling approach, the process-based Biome-BGC model was driven by distributed meteorological station data and was informed by Landsat-based coverages of forest stand age and disturbance regime. In the diagnostic modeling approach, the quasi-mechanistic CFLUX model estimated net ecosystem production (NEP) by upscaling eddy covariance flux tower observations. The model was driven by distributed climate data and MODIS FPAR (the fraction of incident PAR that is absorbed by the vegetation canopy). It was informed by coarse resolution (1 km) data about forest stand age. In both the prognostic and diagnostic modeling approaches, emissions estimates for biomass burning, harvested products, and river/stream evasion were added to model-based NEP to get NEE. The inversion model (CarbonTracker) relied on observations of atmospheric CO2 concentration to optimize prior surface carbon flux estimates. The Pacific Northwest is heterogeneous with respect to land cover and forest management, and repeated surveys of forest inventory plots support the presence of a strong regional carbon sink. The diagnostic model suggested a stronger carbon sink than the prognostic model, and a much larger sink that the inversion model. The introduction of Landsat data on disturbance history served to reduce uncertainty with respect to regional NEE in the diagnostic and prognostic modeling approaches. The FPAR data was particularly helpful in capturing the seasonality of the carbon flux using the diagnostic modeling approach. The inversion approach took advantage of a global

  20. The Discrimination of Graphical Elements

    Science.gov (United States)

    2001-01-01

    perceptual features. Cogmt1ve operatiOns are neeJed to perform the task accUJalely. \\Ve propose th.H the observer performs a rallo esiimation...Expeument 2. In cond!lwns where perceptu.1l featUies cannot provtde the necessary wformauon, the model proposes that mental rallos (denved quant1t1es...Gwde Cambndge Umverslly Press. Cambndge McEwan JSA 1994 Opllmmng Lme Graph A fpect Rallo PhD thesiS, Umversity of Watkato, New Zealand Petru~tc WM

  1. Qualitative Maintenance Experience Handbook

    Science.gov (United States)

    1975-10-20

    rubber bumper asserbly which ps a art of the hook shank to "A" frame assembly- This bumber proviees shank centering And absorbs the shock from side...spring. 10. Remove uplock assy (4 nuts and bolts). 11. Remove bumper (4 bolts). INSTALLATION: Reverse of removal, service and rig. FINCTJONAL ’HCH...ccRese raevl osrer.) 1* Di con eck utra(1l. Eneigi.nee WI I TEST MCUIPMENT: External Hydraulic Power CLOSE Lip : 2 Small Doors 1 1 Access Panel

  2. Propuesta de programa de intervención psicopedagógica para el desarrollo de las competencias socioemocionales al alumnado con Síndrome de Asperger

    OpenAIRE

    Barceló Moreno, Sonia

    2015-01-01

    El presente trabajo analiza una problemática existente en el aula ordinaria de un centro de Educación Secundaria Obligatoria. Un alumno con Síndrome de Asperger presenta problemas para adaptarse a los cambios que requiere esta nueva etapa, provocándole episodios de rabia. Es por ello, que se llevará a cabo un programa de intervención y modificación de conducta para brindarle al alumno con NEE, los instrumentos necesarios para comprender su entorno social y mejorar su desarrollo personal. Por...

  3. An Analysis of the Impact of Job Search Behaviors on Air Force Company Grade Officer Turnover

    Science.gov (United States)

    2012-03-01

    ll’lo foltowi-Dg l$11gMer.~J question ;) nd may not nee-Hsarlly retate to your most sewre Injury. 170, If you knew t hat wearing ankle braces durtng...1994). The populations Blau (1994) studied were registered nurses , insurance employees, pharmaceutical managers, hospital employees, and college...area for approptiate awon SURVEY ELIGIBIU TY A ND POTENTIAL BENEFITS: 0 M0C uses well•ettabk$hed, soent& prooec:tures tO sele¢1 a samc:te thai

  4. Final Technical Report Interannual Variations in the Rate of Carbon Storage by a Mid-Latitude Forest

    Energy Technology Data Exchange (ETDEWEB)

    Wofsy, Steven; Munger, J W

    2012-07-31

    The time series of Net Ecosystem Exchange (NEE) of carbon by an entire forest ecosystem on time scales from hourly to decadal was measured by eddy-covariance supplemented with plot-level measurements of biomass and tree demography. The results demonstrate the response of forest carbon fluxes and long-term budgets to climatic factors and to successional change. The data from this project have been extensively used worldwide by the carbon cycle science community in support of model development and validation of remote sensing observations.

  5. Regional CO2 and latent heat surface fluxes in the Southern Great Plains: Measurements, modeling, and scaling

    Energy Technology Data Exchange (ETDEWEB)

    Riley, W. J.; Biraud, S.C.; Torn, M.S.; Fischer, M.L.; Billesbach, D.P.; Berry, J.A.

    2009-08-15

    Characterizing net ecosystem exchanges (NEE) of CO{sub 2} and sensible and latent heat fluxes in heterogeneous landscapes is difficult, yet critical given expected changes in climate and land use. We report here a measurement and modeling study designed to improve our understanding of surface to atmosphere gas exchanges under very heterogeneous land cover in the mostly agricultural U.S. Southern Great Plains (SGP). We combined three years of site-level, eddy covariance measurements in several of the dominant land cover types with regional-scale climate data from the distributed Mesonet stations and Next Generation Weather Radar precipitation measurements to calibrate a land surface model of trace gas and energy exchanges (isotope-enabled land surface model (ISOLSM)). Yearly variations in vegetation cover distributions were estimated from Moderate Resolution Imaging Spectroradiometer normalized difference vegetation index and compared to regional and subregional vegetation cover type estimates from the U.S. Department of Agriculture census. We first applied ISOLSM at a 250 m spatial scale to account for vegetation cover type and leaf area variations that occur on hundred meter scales. Because of computational constraints, we developed a subsampling scheme within 10 km 'macrocells' to perform these high-resolution simulations. We estimate that the Atmospheric Radiation Measurement Climate Research Facility SGP region net CO{sub 2} exchange with the local atmosphere was -240, -340, and -270 gC m{sup -2} yr{sup -1} (positive toward the atmosphere) in 2003, 2004, and 2005, respectively, with large seasonal variations. We also performed simulations using two scaling approaches at resolutions of 10, 30, 60, and 90 km. The scaling approach applied in current land surface models led to regional NEE biases of up to 50 and 20% in weekly and annual estimates, respectively. An important factor in causing these biases was the complex leaf area index (LAI) distribution

  6. Initial shifts in nitrogen impact on ecosystem carbon fluxes in an alpine meadow: patterns and causes

    Directory of Open Access Journals (Sweden)

    B. Song

    2017-09-01

    Full Text Available Increases in nitrogen (N deposition can greatly stimulate ecosystem net carbon (C sequestration through positive N-induced effects on plant productivity. However, how net ecosystem CO2 exchange (NEE and its components respond to different N addition rates remains unclear. Using an N addition gradient experiment (six levels: 0, 2, 4, 8, 16, 32 gN m−2 yr−1 in an alpine meadow on the Qinghai–Tibetan Plateau, we explored the responses of different ecosystem C fluxes to an N addition gradient and revealed mechanisms underlying the dynamic responses. Results showed that NEE, ecosystem respiration (ER, and gross ecosystem production (GEP all increased linearly with N addition rates in the first year of treatment but shifted to N saturation responses in the second year with the highest NEE (−7.77 ± 0.48 µmol m−2 s−1 occurring under an N addition rate of 8 gN m−2 yr−1. The saturation responses of NEE and GEP were caused by N-induced accumulation of standing litter, which limited light availability for plant growth under high N addition. The saturation response of ER was mainly due to an N-induced saturation response of aboveground plant respiration and decreasing soil microbial respiration along the N addition gradient, while decreases in soil microbial respiration under high N addition were caused by N-induced reductions in soil pH. We also found that various components of ER, including aboveground plant respiration, soil respiration, root respiration, and microbial respiration, responded differentially to the N addition gradient. These results reveal temporal dynamics of N impacts and the rapid shift in ecosystem C fluxes from N limitation to N saturation. Our findings bring evidence of short-term initial shifts in responses of ecosystem C fluxes to increases in N deposition, which should be considered when predicting long-term changes in ecosystem net C sequestration.

  7. Modeling carbon dynamics in two adjacent spruce forests with different soil conditions in Russia

    Directory of Open Access Journals (Sweden)

    J. Kurbatova

    2008-07-01

    Full Text Available Net ecosystem carbon exchange (NEE was measured with eddy covariance method for two adjacent forests located at the southern boundary of European taiga in Russia in 1999–2004. The two spruce forests shared similar vegetation composition but differed in soil conditions. The wet spruce forest (WSF possessed a thick peat layer (60 cm with a high water table seasonally close to or above the soil surface. The dry spruce forest (DSF had a relatively thin organic layer (5 cm with a deep water table (>60 cm. The measured multi-year average NEE fluxes (2000 and –1440 kg C ha−1yr−1 for WSF and DSF, respectively indicated that WSF was a source while DSF a sink of atmospheric carbon dioxide (CO2 during the experimental years. A process-based model, Forest-DNDC, was employed in the study to interpret the observations. The modeled multi-year average NEE fluxes were 1800 and –2200 kg C ha−1yr−1 for WSF and DSF, respectively, which were comparable with observations. The modeled data also showed high soil heterotrophic respiration rates at WSF that suggested that the water table fluctuation at WSF could have played a key role in determining the negative carbon balance in the wetland ecosystem. A sensitivity test was conducted by running Forest-DNDC with varied water table scenarios for WSF. The results indicated that the NEE fluxes from WSF were highly sensitive to the water table depth. When the water table was high, the WSF ecosystem maintained as a sink of atmospheric CO2; while along with the drop of the water table the length of the flooded period reduced and more organic matter in the soil profile suffered from rapid decomposition that gradually converted the ecosystem into a source of atmospheric CO2. The general effect of water table variation on wetland carbon balance observed from this modeling study could be applicable for a wide range of wetland ecosystems that

  8. Increased carbon sequestration in a Danish beech forest during 1996-2016: Observations and hypotheses.

    Science.gov (United States)

    Pilegaard, Kim; Ibrom, Andreas

    2017-04-01

    A study of the net exchange of CO2 (NEE) between the atmosphere and a beech forest near Sorø, Denmark, during 14 years (1996-2009) showed that the beech forest acted as an increasing sink of CO2 [1]. A significant increase in gross primary production (GPP) and a smaller and not significant increase in ecosystem respiration (RE) were also found. Thus, the increased NEE was mainly attributed to an increase in GPP. The length of the carbon uptake period (CUP) significantly increased, whereas there was a no increase in the leafed period (LP). This means that the leaves stayed active longer. The increase in the carbon uptake period explained about half of the increasing NEE. The remaining increase was believed to be due to an observed increased uptake capacity of the canopy and increased annual radiation efficiency[2]. The causes for this were hypothesized to be a combination of increase in atmospheric CO2 concentration, higher summer precipitation, and increased availability of N. A higher nitrogen content in the leaves was observed towards the end of the observation period. An updated analysis of the flux data, now including the years 1996-2016, confirms the increasing trend in carbon sequestration of the forest, an increasingly longer growing season, and a significant correlation of NEE and CUP, however, similarly to the first study, the increase in CUP only explains about half of the total increase. Here we investigate three hypotheses for the remaining reasons for the increase: H1: increased canopy nitrogen content H2: carbon dioxide fertilisation H3: increased water availability due to changing precipitation patterns. We describe the multiannual development of canopy photosynthesis capacity with regression analysis and perform sensitivity studies with the canopy model MAESTRA [3] to investigate the above hypotheses. The results will be presented, critically discussed and interpreted with respect to general effects of global climate change and site specific, local

  9. A study of ovule-to-seed development in Ceratiosicyos (Achariaceae and the systematic position of the genus

    Directory of Open Access Journals (Sweden)

    E. M. A. Steyn

    2002-12-01

    Full Text Available A light microscope study of developing ovules and seeds of Ceratiosicyos laevis (Thunb. A.Meeuse was undertaken to aug­ment an investigation of ovule and seed structure in Achariaceae. a tri-generic family comprising three species of herbaceous perennials endemic to southern Africa. Tests for myrmecochory suggest that seed of Ceratiosicyos Nees is not dispersed by ants like those of Acharia Thunb. and Guthriea Bolus. Structural differences include the absence of a raphal ridge and imbibition lidand the presence of long funicles and medium-sized embryos in Ceratiosicyos.

  10. Cytogenetic studies in some representatives of the subfamily Pooideae (Poaceae in South Africa. 2. The tribe Aveneae, subtribes Phalaridinae and Alopecurinae

    Directory of Open Access Journals (Sweden)

    J. J. Spies

    1996-12-01

    Full Text Available This is a report on chromosome numbers for the subtribes Phalaridinae and Alopecurinae (tribe Aveneae which are. to a large extent, naturalized in South Africa. Chromosome numbers of 34 specimens, representing nine species and four genera, are presented. These numbers include the first report on Agrostis avenacea Gmel. (n = 4x = 28. New ploidv levels are reported for Phalaris aquatica L. (n = x = 7, Agrostis barbuligera Stapf var. barbuligera (n = 2x = 14 and n = 4x = 28 and A.  lachnantha Nees var.  lachnantha (n = 3x = 21.

  11. Cognitive training programme for children and adolescents with special learning needs

    OpenAIRE

    Mota, Angelina Ferraz da

    2006-01-01

    Com esta investigação pretendemos fazer o ponto da situação relativamente à problemática das Dificuldades de Aprendizagem (DA), sua identificação, avaliação e intervenção, em Portugal, comparativamente com outros países, analisando os normativos legislativos e as perspectivas actuais de atendimento educativo, no seio do movimento da escola inclusiva. Intentamos, ainda, construir e avaliar os efeitos de um programa de estimulação cognitiva dirigido a adolescentes com NEE, designadamente, Dific...

  12. Differentiation of Alternaria infectoria and Alternaria alternata based on morphology, metabolite profiles, and cultural characteristics

    DEFF Research Database (Denmark)

    Andersen, Birgitte; Thrane, Ulf

    1996-01-01

    Some small-spored species belonging to the genus Alternaria Nees have been studied according to their chemical, morphological, and cultural characteristics. A data matrix was constructed based on a combination of characters. Cluster analysis of the combined data set showed good resolution of two...... groups of small-spored Alternaria the Alternaria infectoria group and the Alternaria alternata group. Isolates in the A. infectoria group produced only unique metabolites of unknown identity, whereas all isolates in the A. alternata group produced alternariol and alternariol monomethyl ether. Furthermore...

  13. Failure analysis a practical guide for manufacturers of electronic components and systems

    CERN Document Server

    Bâzu, Marius

    2011-01-01

    Failure analysis is the preferred method to investigate product or process reliability and to ensure optimum performance of electrical components and systems. The physics-of-failure approach is the only internationally accepted solution for continuously improving the reliability of materials, devices and processes. The models have been developed from the physical and chemical phenomena that are responsible for degradation or failure of electronic components and materials and now replace popular distribution models for failure mechanisms such as Weibull or lognormal. Reliability engineers nee

  14. Ectopic fat accumulation in patients with COPD: an ECLIPSE substudy

    OpenAIRE

    Martin M.; Almeras N; Després JP; Coxson HO; Washko GR; Vivodtzev I; Wouters EFM; Rutten E; Williams MC; Murchison JT; MacNee W; Sin DD; Maltais F

    2017-01-01

    Mickaël Martin,1 Natalie Almeras,1 Jean-Pierre Després,1 Harvey O Coxson,2 George R Washko,3 Isabelle Vivodtzev,4 Emiel FM Wouters,5 Erica Rutten,6 Michelle C Williams,7 John T Murchison,8 William MacNee,7 Don D Sin,2 François Maltais1 On behalf of the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) Study Group 1Research Centre, Institut universitaire de cardiologie et de pneumologie de Québec, Universit&ea...

  15. The cultivation of energy crops for biogas production and the application of digestates are characterized by high variability of CO2 exchange and soil organic C stock changes

    Science.gov (United States)

    Augustin, Juergen; Fiedler, Sebastian; Heintze, Gawan; Rohwer, Marcus; Prescher, Anne-Katrin; Pohl, Madlen; Jurisch, Nicole; Hagemann, Ulrike

    2017-04-01

    In Germany, agricultural production accounts for approx. 15% of total anthropogenic greenhouse gas emissions. The cultivation of energy crops is thus considered an important option to reduce the climate impact and maintain or increase soil organic carbon (SOC) stocks. In particular, this applies to the continuously expanding cultivation of energy crops for biogas production and the associated use of residues from anaerobic digestion (digestates) as organic fertilizer. To date, there is only limited and contradicting evidence on the impacts of this management practice on the CO2 exchange as well as the change of SOC stocks. We will present results from a 4-year field study at 5 sites in Germany using identical methods to investigate the interacting effects of i) 3 N-fertilizer treatments including calcium ammonium nitrate and digestates and ii) a crop rotation of 7 energy crops like maize, sorghum, triticale, and wheat on net ecosystem CO2 exchange (NEE) and the change of SOC stocks. We used the manual chamber approach for measuring NEE as the difference between gross primary production and ecosystem respiration. The determination of SOC stock changes was based on a C budget approach, which includes the cumulated annual NEE, the C export by harvest, and the C import by application of anaerobic digestates. The CO2 exchange and the change of SOC stocks were influenced by multiple factors like crop, site, fertilization, and climate, as well as their complex interactions. A large proportion of the variability of the CO2 exchange can be attributed to interannual climatic variability. Productive crops like maize and sorghum generally feature the most intensive CO2 exchange, while less productive crops can compensate for this by means of longer cultivation times. Regardless of the extreme variability, pronounced and partly significant differences of NEE and C budgets between sites were observed. On average, SOC stocks declined over a full crop rotation, but with highly

  16. Joe Celko's Data, Measurements and Standards in SQL

    CERN Document Server

    Celko, Joe

    2009-01-01

    Joe Celko has looked deep into the code of SQL programmers and found a consistent and troubling pattern - a frightening lack of consistency between their individual encoding schemes and those of the industries in which they operate. This translates into a series of incompatible databases, each one an island unto itself that is unable to share information with others in an age of internationalization and business interdependence. Such incompatibility severely hinders information flow and the quality of company data. Data, Measurements and Standards in SQL reveals the shift these programmers nee

  17. Thermal Acclimation and Adaptation of Net Ecosystem Carbon Exchange (Invited)

    Science.gov (United States)

    Luo, Y.; Niu, S.; Fei, S.; Yuan, W.; Zhang, Z.; Schimel, D.; Fluxnet Pis, .

    2010-12-01

    Ecosystem responses to temperature change are collectively determined by its constituents, which are plants, animals, microbes, and their interactions. It has been long documented that all plant, animals, and microbial carbon metabolism (photosynthesis, respiration) can acclimate and respond to changing temperatures, influencing the response of ecosystem carbon fluxes to climate change. Climate change also can induce competition between species with different thermal responses leading to changes in community composition. While a great deal of research has been done on species-level responses to temperature, it is yet to examine thermal acclimation of adaptation of ecosystem carbon processes to temperature change. With the advent of eddy flux measurements, it is possible to directly characterize the ecosystem-scale temperature response of carbon storage. In this study, we quantified the temperature response functions of net ecosystem carbon exchange (NEE), from which the responses of apparent optimal temperatures across broad spatial and temporal scales were examined. While temperature responses are normally parameterized in terms of the physiological variables describing photosynthesis and respiration, we focus on the apparent optimal behavior of NEE. Because the measurement integrated over multiple individuals and species within the footprint of the measurement (100s to 1000s of ha), it is challenging to interpret this measurement in terms of classical physiological variables such as the Q10. Rather we focus on the realized behavior of the ecosystem and its sensitivity to temperature. These empirical response functions can then be used as a benchmark for model evaluation and testing. Our synthesis of 656 site-years of eddy covariance data over the world shows that temperature response curves of NEE are parabolic, with their optima temperature strongly correlated with site growing season temperature across the globe and with annual mean temperature over years at

  18. Net ecosystem carbon exchange in three contrasting Mediterranean ecosystems – the effect of drought

    Directory of Open Access Journals (Sweden)

    T. S. David

    2007-09-01

    Full Text Available Droughts reduce gross primary production (GPP and ecosystem respiration (Reco, contributing to most of the inter-annual variability in terrestrial carbon sequestration. In seasonally dry climates (Mediterranean, droughts result from reductions in annual rainfall and changes in rain seasonality. We compared carbon fluxes measured by the eddy covariance technique in three contrasting ecosystems in southern Portugal: an evergreen oak woodland (savannah-like with ca.~21% tree crown cover, a grassland dominated by herbaceous annuals and a coppiced short-rotation eucalyptus plantation. During the experimental period (2003–2006 the eucalyptus plantation was always the strongest sink for carbon: net ecosystem exchange rate (NEE between −861 and −399 g C m−2 year−1. The oak woodland and the grassland were much weaker sinks for carbon: NEE varied in the oak woodland between −140 and −28 g C m−2 year−1 and in the grassland between −190 and +49 g C m−2 year−1. The eucalyptus stand had higher GPP and a lower proportion of GPP spent in respiration than the other systems. The higher GPP resulted from high leaf area duration (LAD, as a surrogate for the photosynthetic photon flux density absorbed by the canopy. The eucalyptus had also higher rain use efficiency (GPP per unit of rain volume and light use efficiency (the daily GPP per unit incident photosynthetic photon flux density than the other two ecosystems. The effects of a severe drought could be evaluated during the hydrological-year (i.e., from October to September of 2004–2005. Between October 2004 and June 2005 the precipitation was only 40% of the long-term average. In 2004–2005 all ecosystems had GPP lower than in wetter years and carbon sequestration was strongly restricted (less negative NEE. The grassland was a net source of carbon dioxide (+49 g C m−2 year−1. In the oak woodland a large proportion of GPP resulted from carbon assimilated by its annual vegetation

  19. CONCEPT OF RASAYANA IN RASA SHASTRA

    OpenAIRE

    Tripathi R; Kiran

    2012-01-01

    In all the literatures of Rasa shastra, the word Rasayana has been used in two senses, one for medicine as a whole for example “Kupipakva Rasayana” and for whole group of medicines having mercury or other minerals in them. Others have used this word for “rejuvenation” while describing the properties of a substance or in specific chapters entitled Rasayana. So going through our rasa shastra texts, we find an extensive description of Rasayana with better herbo-mineral combinations. There is nee...

  20. Carbon balance at represenative agroecosystems of Central European Russia with different crops assessed by eddy covariance method

    Science.gov (United States)

    Yaroslavtsev, Alexis; Meshalkina, Joulia; Mazirov, Ilya

    2016-04-01

    Despite the fact that in Russia cropland's soils carbon loses 9 time higher than forest's soils ones (Stolbovoi, 2002), agroecosystems were not given sufficient attention and most of the papers are devoted to forestry and natural ecosystems. Carbon balance was calculated at the Precision Farming Experimental Fields of the Russian Timiryazev State Agricultural University, Moscow, Russia, for two agroecosystems with different crops from the same crop rotation studied for 2 years. The experimental site has a temperate and continental climate and situated in south taiga zone with Arable Sod-Podzoluvisols (Albeluvisols Umbric). Vertical fluxes of carbon dioxide were measured with eddy covariance technique, statistical method to measure and calculate turbulent fluxes within atmospheric boundary layers (Burba, 2013). Crop rotation included potato, winter wheat, barley and vetch and oat mix. Two fields of the same crop rotation were studied in 2013-2014. One of the fields (A) was used in 2013 for barley planting (Hordeum vulgare L.). The field B was in 2013 used for planting together vetch (Vicia sativa L.) and oats (Avena sativa L.). Inversely oats and vetch grass mixt was sown in 2014 on field A. Winter wheat was sown on field A in the very beginning of September. On the second field (B) in 2014 winter wheat occurred from under the snow in the phase of tillering, after harvesting it in mid of July, white mustard (Sinapis alba) was sown for green manure. Carbon uptake (NEE negative values) was registered only for the field with winter wheat and white mustard; perhaps because the two crops were cultivated on the field within one growing season. Three other cases showed CO2 emission. Great difference in 82 g C m-2 per year in NEE between two fields with vetch and oat mix was related to higher difference in grass yields. NEE for barley field was positive during the whole year; considering only the growing season, NEE for barley was 100 g C m-2 lower and was negative. Closed

  1. Competenza digitale dei docenti e disabilità. Formazione su Episodi di Apprendimento Situato (EAS) per l'innovazione didattica

    OpenAIRE

    Messina, Salvatore

    2017-01-01

    En la presente tesis doctoral se desarrolla un estudio de investigación que persigue la formación de docentes que trabajan con alumnado con necesidades educativas especiales (AcNEE), tanto en contextos de aulas ordinarias como especiales, para el desarrollo de su competencia digital. Se diseña, desarrolla y evalúa un proceso formativo basado en la metodología EAS (Episodios de Aprendizaje Situado) y su aplicación a las aulas. Participan maestros españoles e italianos a los que se les administ...

  2. Leopold Fellows meet

    Science.gov (United States)

    Hartmann, Dennis L.

    Communicating the results of environmental science research to nonscientists was the focus of a week-long meeting of fellows of the Aldo Leopold Leadership Program (ALLP) in June. Participating were 20 mid-career university facultymembers, the first group of ALLP fellows to be selected.Discussions were held on the role of scientists in society, techniques for effective leadership, improving communications skills, and working productively with news media. The training program considers both print and broadcast media as well as other outreach vehicles. The meeting was held at Kah Nee Ta Resort on the Warm Springs Indian Reservation, Warm Springs, Oregon, June 15-21, 1999.

  3. Imaging a fossil oolitic system with GPR, insights into the exposures of the Isle of Portland (UK)

    DEFF Research Database (Denmark)

    Moreau, Julien; Hansen, Trine Lykke; Nielsen, Lars

    . The papers place a shore line between the Isle and the continent striking NEE-SWW and facing towards the Channel. Facies changes are attributed to rapid sea-level variations and Walter’s Law.Following some preliminary field observations, we have decided to shoot an extensive GPR survey of the same...... stratigraphic interval (The Portland Freestone). With a total of 85 GPR profiles, we have produced grids on top of most of the coastal cliffs and quarry faces. We have encountered 3 main architectures, 2-m-high bars with steep clinoforms, 10s of metres-wide channels plugged with a variety of organism...

  4. Influence of the extreme weather events on carbon fluxes in southern European taiga

    Science.gov (United States)

    Kurbatova, J.; Shalukhina, N.; Tatarinov, F.; Varlagin, A.

    2009-04-01

    The question on an arrangement, scales and the factors determining ground sink of CO2 in a forest zone of Russia is opened and discussed. To estimate of global and regional fluxes of carbon for the different periods of time various methods and modeling calculations are used. For an experimental estimation of carbon fluxes for ecosystem level of averaging the eddy covariance method now is widely used. It allows continuously, all-the-year-round, with the high time sanction to register net ecosystem exchange (NEE), fluxes of a water and heat between forest and an atmosphere. Registration of meteorological parameters of an atmosphere is simultaneously carried out. It allows to find the dependence of deposition or issue of carbon on environmental factors. In territory of Russia the observation of carbon fluxes were begun within the framework of the international projects of EU in 1998. Now there is the eddy covariance complex in a southern European taiga, in territory Central Forest Reserve. The measurements are carried out in uneven-age spruce forest (Sphagnum-Vaccinium myrtillus ). The choice of object of supervision was caused by a wide circulation of similar types of forest in the European taiga. In general the 10-years period of measurements has captured a wide range of changes of climatic conditions. The years with extreme - droughty and damp vegetative seasons and also years approached to average climatic norms for this region were during the observations. The high daily, seasonal and annual variability of deposition and issue of carbon is characteristic for spruce forests. The results of measurements of NEE have shown that southern taiga can function during the vegetative period both as a source, and as a sink of carbon for an atmosphere. The cumulative fluxes of NEE for the period April - October depend first of all on temperature and precipitation in the spring period with temperature in a range 5-10C and from duration of this period, and for the period of

  5. Trastornos del desarrollo, discapacidad y necesidades educativas especiales. Elementos psicoeducativos

    OpenAIRE

    Luque Parra, Diego Jesús

    2003-01-01

    En este artículo los autores se proponen analizar los términos de «trastornos del desarrollo, discapacidad» que pueda asociársele y las «necesidades educativas especiales (NEEs)» desde una visión integrada, tanto en lo individual como en lo social, dentro de ambientes educativos. Así, primeramente se define trastorno del desarrollo desde una perspectiva psicológica, para pasar después a una valoración del mismo en conjunción con la discapacidad (social y psicosocial). Enmarcados ambos término...

  6. Exchange of CO2 in Arctic tundra: impacts of meteorological variations and biological disturbance

    Directory of Open Access Journals (Sweden)

    E. López-Blanco

    2017-10-01

    Full Text Available An improvement in our process-based understanding of carbon (C exchange in the Arctic and its climate sensitivity is critically needed for understanding the response of tundra ecosystems to a changing climate. In this context, we analysed the net ecosystem exchange (NEE of CO2 in West Greenland tundra (64° N across eight snow-free periods in 8 consecutive years, and characterized the key processes of net ecosystem exchange and its two main modulating components: gross primary production (GPP and ecosystem respiration (Reco. Overall, the ecosystem acted as a consistent sink of CO2, accumulating −30 g C m−2 on average (range of −17 to −41 g C m−2 during the years 2008–2015, except 2011 (source of 41 g C m−2, which was associated with a major pest outbreak. The results do not reveal a marked meteorological effect on the net CO2 uptake despite the high interannual variability in the timing of snowmelt and the start and duration of the growing season. The ranges in annual GPP (−182 to −316 g C m−2 and Reco (144 to 279 g C m−2 were  > 5 fold larger than the range in NEE. Gross fluxes were also more variable (coefficients of variation are 3.6 and 4.1 % respectively than for NEE (0.7 %. GPP and Reco were sensitive to insolation and temperature, and there was a tendency towards larger GPP and Reco during warmer and wetter years. The relative lack of sensitivity of NEE to meteorology was a result of the correlated response of GPP and Reco. During the snow-free season of the anomalous year of 2011, a biological disturbance related to a larvae outbreak reduced GPP more strongly than Reco. With continued warming temperatures and longer growing seasons, tundra systems will increase rates of C cycling. However, shifts in sink strength will likely be triggered by factors such as biological disturbances, events that will challenge our forecasting of C states.

  7. Anywhere the Wind Blows does Really Matter

    Science.gov (United States)

    Montaldo, Nicola; Oren, Ram

    2014-05-01

    The variation of net ecosystem carbon exchange (NEE) has been explained at coarse scales with variation of forcing variables among climate regions and associated biomes, at the intermediate, mesoscale, with differences among dominating vegetation types and conditions, and at the misoscale with heterogeneity of the eddy covariance footprint properties. Wind is rarely considered in analysis of surface fluxes for its effects on periodic budgets of water and carbon. In many regions conditions change frequently between maritime and continental depending on wind velocity (VW) and direction. In these regions, water and carbon fluxes may respond to mesoscale weather patterns extending maritime influences far inland. Using eddy-covariance data from Sardinia, we show that daytime net carbon exchange (NEE) of a mixed pasture-woodland (grass-wild olive) ecosystem (Detto et al., 2006; Montaldo et al., 2008) increased with VW, especially during summer-dry conditions. As VW increased, the air, humidified over sea, remains relatively moist and cool to a greater distance inland, reaching only ~50 km during slow Saharan Sirocco wind but >160 km during mostly Mistral wind (4 m/s) from Continental Europe. A 30% lower vapor pressure deficit (D) associated with high VW (average 2 kPa at 4 m/s), allowed a 50% higher canopy stomatal conductance (gc) and, thus, photosynthesis. However, because gc and D have opposite effects on evapotranspiration (Ee), Ee was unaffected by VW. Thus, higher NEE during summertime Mistral reflects increased ecosystem water-use efficiency (We) and a departure from a costly carbon-water tradeoff. Yet many regions often experience high velocity winds, attention is typically focused on the capacity of strong winds to fan regional fires, threatening human habitation and natural habitats, and reducing Carbon storage (C), NEE and latent heat flux. However, depending on their origin, high velocity winds can bring continental air to the coast (e.g., Santa Ana winds

  8. Very high CO2 exchange fluxes at the peak of the rainy season in a West African grazed semi-arid savanna ecosystem

    DEFF Research Database (Denmark)

    Tagesson, Håkan Torbern; Ardoe, Jonas; Guiro, Idrissa

    2016-01-01

    Africa is a sink of carbon, but there are large gaps in our knowledge regarding the CO2 exchange fluxes for many African ecosystems. Here, we analyse multi-annual eddy covariance data of CO2 exchange fluxes for a grazed Sahelian semi-arid savanna ecosystem in Senegal, West Africa. The aim...... to that of other semi-arid savanna sites due the short length of the rainy season. An inter-comparison between the open-path and a closed-path infrared sensor indicated no systematic errors related to the instrumentation. An uncertainty analysis of long-term NEE budgets indicated that corrections for air density...... response to climate change....

  9. Exchange of CO2 in Arctic tundra: impacts of meteorological variations and biological disturbance

    Science.gov (United States)

    López-Blanco, Efrén; Lund, Magnus; Williams, Mathew; Tamstorf, Mikkel P.; Westergaard-Nielsen, Andreas; Exbrayat, Jean-François; Hansen, Birger U.; Christensen, Torben R.

    2017-10-01

    An improvement in our process-based understanding of carbon (C) exchange in the Arctic and its climate sensitivity is critically needed for understanding the response of tundra ecosystems to a changing climate. In this context, we analysed the net ecosystem exchange (NEE) of CO2 in West Greenland tundra (64° N) across eight snow-free periods in 8 consecutive years, and characterized the key processes of net ecosystem exchange and its two main modulating components: gross primary production (GPP) and ecosystem respiration (Reco). Overall, the ecosystem acted as a consistent sink of CO2, accumulating -30 g C m-2 on average (range of -17 to -41 g C m-2) during the years 2008-2015, except 2011 (source of 41 g C m-2), which was associated with a major pest outbreak. The results do not reveal a marked meteorological effect on the net CO2 uptake despite the high interannual variability in the timing of snowmelt and the start and duration of the growing season. The ranges in annual GPP (-182 to -316 g C m-2) and Reco (144 to 279 g C m-2) were > 5 fold larger than the range in NEE. Gross fluxes were also more variable (coefficients of variation are 3.6 and 4.1 % respectively) than for NEE (0.7 %). GPP and Reco were sensitive to insolation and temperature, and there was a tendency towards larger GPP and Reco during warmer and wetter years. The relative lack of sensitivity of NEE to meteorology was a result of the correlated response of GPP and Reco. During the snow-free season of the anomalous year of 2011, a biological disturbance related to a larvae outbreak reduced GPP more strongly than Reco. With continued warming temperatures and longer growing seasons, tundra systems will increase rates of C cycling. However, shifts in sink strength will likely be triggered by factors such as biological disturbances, events that will challenge our forecasting of C states.

  10. Aplikasi Rehabilitasi Dan Terapi Tangan Untuk Pasien Stroke Dengan Menggunakan Kinect

    OpenAIRE

    Christian, Max; Liliana, Liliana; Sandjaja, Iwan Njoto

    2017-01-01

    Stroke is one of the most common cause of death after heart disease and cancer. Stroke occurs when an artery to the brain is blocked. Lots of things may cause stroke to different people, some of them are smoking, high blood pressures and sickle cells. One of the common kind of stroke is hemiplegia which makes the person who suffers from it loses the ability to move half of their body parts.For a person that suffer stroke to reavh full or almost full recovery, a continuos rehabilitation is nee...

  11. Ernst Enno 121 : [Ernst Enno nimelise kirjandusliku omaloominguvõistluse 1996. aasta paremad luuletused

    Index Scriptorium Estoniae

    1996-01-01

    Janek Nee (Haapsalu Wiedemanni gümnaasiumi 11. kl.). Teed lõpmatusse; Liina Krips (Haapsalu gümnaasiumi 12. kl.). Inimene, 'Olin arvanud, et minust hoolitakse...'; Loola Hütt (Haapsalu sanatoorse internaatkooli 13. kl.). 'Mäletad kui hele oli kuu..., 'Jälle ei jõa kuu...', 'Suveöö sumedates silmapilkudes...'; Evelin Lillepuu (Taebla gümnaasiumi 9. kl.). Tuul; Anne Roovere (Kullamaa keskk. 8. kl.). See on koht; Martin Kaasik (Haapsalu Wiedemanni gümnaasiumi 7. kl.). Vembumehed; Külli Kivi (Haapsalu Wiedemanni gümnaasiumi 9. kl.). Vaikus

  12. Acoso escolar y necesidades educativas especiales

    OpenAIRE

    González Contreras, Ana Isabel

    2017-01-01

    Se pretende describir, analizar y comparar el acoso y/o maltrato escolar desde el punto de vista de las víctimas, testigos y agresores con y sin Necesidades Educativas Especiales (NEE) en los centros de Extremadura. Como instrumentos se utilizaron los siguientes: la versión abreviada del Cuestionario del Defensor del Pueblo-UNICEF (2007), las Escalas de Afecto (EA-H) y de Normas y Exigencias (ENE-H) de (Fuentes, Motrico y Bersabé, 1999) y el Cuestionario Educativo-clínico: Ansiedad y depresió...

  13. Direct and indirect controls of the interannual variability in atmospheric CO2 exchange of three contrasting ecosystems in Denmark

    DEFF Research Database (Denmark)

    Jensen, Rasmus; Herbst, Mathias; Friborg, Thomas

    2017-01-01

    neighboring sites (agriculture, forest, and meadow) subjected to management in variable degree were evaluated to determine typical CO2 budgets and controlling factors of IAV. In terms of average annual net ecosystem exchange (NEE) the agricultural and wet meadow site showed identical rates of −156 (±110......The understanding of the controlling factors determining interannual variability (IAV) of carbon dioxide (CO2) exchange between different ecosystems is crucial when assessing present and future responses to climate variability and climate change. Six years of eddy covariance (EC) data from three...

  14. An Efficient Multi-path Routing Algorithm Based on Hybrid Firefly Algorithm for Wireless Mesh Networks

    OpenAIRE

    K. Kumaravel; A. Marimuthu

    2015-01-01

    Wireless Mesh Network (WMN) uses the latest technology which helps in providing end users a high quality service referred to as the Internet’s “last mile”. Also considering WMN one of the most important technologies that are employed is multicast communication. Among the several issues routing which is significantly an important issue is addressed by every WMN technologies and this is done during the process of data transmission. The IEEE 802.11s Standard entails and sets procedures which nee...

  15. La colaboración entre maestros/maestras y padres/madres para atender a la diversidad en las instituciones educativas

    OpenAIRE

    Ronald Soto Calderón; Francisco Javier Hinojo Lucena

    2004-01-01

    En este artículo se resalta la importancia de un trabajo conjunto entre los padres y madres de familia de personas con necesidades educativas especiales y los docentes, y las diferentes formas en que esta labor se puede realizar. También se comentan los diferentes planos en los que se puede llevar a cabo un trabajo cooperativo, de tal manera que lo importante siempre se enfoque a la atención educativa de los estudiantes con NEE, se mencionan también algunos puntos que pueden ser tomados en cu...

  16. Annual net ecosystem exchanges of carbon dioxide and methane from a temperate brackish marsh: should the focus of marsh restoration be on brackish environments?

    Science.gov (United States)

    Windham-Myers, L.; Anderson, F. E.; Bergamaschi, B. A.; Ferner, M. C.; Schile, L. M.; Spinelli, G.

    2015-12-01

    The exchange and transport of carbon in tidally driven, saline marsh ecosystems provide habitat and trophic support for coastal wildlife and fisheries, while potentially accumulating and storing carbon at some of the highest rates compared to other ecosystems. However, due to the predicted rise in sea level over the next century, the preservation and restoration of estuarine habitats is necessary to compensate for their expected decline. In addition, restoration of these marsh systems can also reduce the impacts of global climate change as they assimilate as much carbon as their freshwater counterparts, while emitting less methane due to the higher concentrations of sulfate in seawater. Unfortunately, in brackish marshes, with salinity concentrations less than 18 parts per thousand (ppt), simple relationships between methane production, salinity and sulfate concentrations are not well known. Here we present the net ecosystem exchange (NEE) of carbon dioxide and methane, as calculated by the eddy covariance method, from a brackish marsh ecosystem in the San Francisco Estuary where salinity ranges from oligohaline (0.5-5 ppt) to mesohaline (5-18 ppt) conditions. Daily rates of carbon dioxide and methane NEE ranged from approximately 10 gC-CO2 m-2 d-1 and 0 mgC-CH4 m-2 d-1, during the winter to -15 gC-CO2 m-2 d-1 and 30 mgC-CH4 m-2 d-1, in the summer growing season. A comparison between similar measurements made from freshwater wetlands in the Sacramento-San Joaquin Delta found that the daily rates of carbon dioxide NEE were similar, but daily rates of methane NEE were just a small fraction (0-15%). Our research also shows that the daily fluxes of carbon dioxide and methane at the brackish marsh were highly variable and may be influenced by the tidal exchanges of seawater. Furthermore, the observed decline in methane production from summer to fall may have resulted from a rise in salinity and/or a seasonal decline in water and air temperatures. Our research goals are

  17. Welcome to the Potato Powered Cosmos

    CERN Multimedia

    2017-01-01

    As part of the Art@CMS initiative, UK artist Rachael Nee worked with a group of international teachers taking part in the 2017 High School Teacher Programme to produce an art installation. The Potato Powered Cosmos represents CERN as an interrelated system of experiment, machine, energy and people. The installation emphasises the importance of CERN’s community - it doesn’t work without human interaction. Art@CMS has produced a ‘how-to’ guide for other art and science teachers who would like to recreate the Potato Powered Cosmos with their students.

  18. Performative urban Spaces

    DEFF Research Database (Denmark)

    Marling, Gitte

    2010-01-01

    The article examines the background of contemporary life, i.e., the urban teoretical and analytical framework that shows the nee for a pluralistic and open city life. possibilities for developing performative places and spaces for social and cultural exchange will be suggested. The article...... for establishing 'open -minded' urban spaces and public domains. In the fifth section, I present and define a series of analytical concepts related to the experience city's stages and cultural projects. The article ends with a short conclusion and recapitulation....

  19. 5th Paris-Princeton Lectures on Mathematical Finance

    CERN Document Server

    Benth, Fred Espen; Guasoni, Paolo; Manolarakis, Konstantinos; Muhle-Karbe, Johannes; Nee, Colm; Protter, Philip

    2013-01-01

    The current volume presents four chapters touching on some of the most important and modern areas of research in Mathematical Finance: asset price bubbles (by Philip Protter); energy markets (by Fred Espen Benth); investment under transaction costs (by Paolo Guasoni and Johannes Muhle-Karbe); and numerical methods for solving stochastic equations (by Dan Crisan, K. Manolarakis and C. Nee).The Paris-Princeton Lecture Notes on Mathematical Finance, of which this is the fifth volume, publish cutting-edge research in self-contained, expository articles from renowned specialists. The aim is to produce a series of articles that can serve as an introductory reference source for research in the field.

  20. Variation in soil moisture and N availability modulates carbon and water exchange in a California grassland experiment

    Energy Technology Data Exchange (ETDEWEB)

    St. Clair, S.B.; Sudderth, E.; Fischer, M.L.; Torn, M.S.; Stuart, S.; Salve, R.; Eggett, D.; Ackerly, D.

    2009-03-15

    Variability in the magnitude and timing of precipitation is predicted to change under future climate scenarios. The primary objective of this study was to understand how variation in precipitation patterns consisting of soil moisture pulses mixed with intermittent dry down events influence ecosystem gas fluxes. We characterized the effects of precipitation amount and timing, N availability, and plant community composition on whole ecosystem and leaf gas exchange in a California annual grassland mesocosm study system that allowed precise control of soil moisture conditions. Ecosystem CO2 and fluxes increased significantly with greater precipitation and were positively correlated with soil moisture. A repeated 10 day dry down period following 11 days of variable precipitation inputs strongly depressed net ecosystem CO2 exchange (NEE) across a range of season precipitation totals, and plant community types. Ecosystem respiration (Re), evapotranspiration (ET) and leaf level photosynthesis (Amax) showed greatest sensitivity to dry down periods in low precipitation plots. Nitrogen additions significantly increased NEE, Re and Amax, particularly as water availability was increased. These results demonstrate that N availability and intermittent periods of soil moisture deficit (across a wide range of cumulative season precipitation totals) strongly modulate ecosystem gas exchange.

  1. A inclusão na educação infantil de Vitória: contribuições da educação física

    Directory of Open Access Journals (Sweden)

    Alexandre Freitas Marchiori

    2015-10-01

    Full Text Available http://dx.doi.org/10.5007/1980-4512.2015n31p292 O artigo objetiva compreender as possibilidades de uma prática compartilhada e desenvolver proposições que contribuíssem com os processos de inclusão na Educação Infantil. Os sujeitos são professores que atuam no Centro Municipal de Educação Infantil (CMEI de Vitória e duas crianças com necessidades educativas especiais (NEE. O referencial teórico-metodológico fundamenta-se na perspectiva histórico cultural (VYGOTSKY;, 2007; WALLON;, 2010. A perspectiva de professor reflexivo (NÓVOA, 2001 e as concepções metodológicas dos estudos nos/dos/com os cotidianos orienta a produção desse artigo. As fontes foram os registros fotográficos e filmagens das práticas pedagógicas em 2014 e relatórios avaliativos de dois alunos com NEE. A oferta da educação física no currículo da educação infantil amplia as possibilidades do trabalho colaborativo e potencializam as práticas da educação inclusiva.

  2. A young afforestation area in Iceland was a moderate sink to CO2 only a decade after scarification and establishment

    Directory of Open Access Journals (Sweden)

    B. D. Sigurdsson

    2009-12-01

    Full Text Available This study reports on three years (2004–2006 of measurements of net ecosystem exchange (NEE over a young Siberian larch plantation in Iceland established on previously grazed heathland pasture that had been scarified prior to planting. The study evaluated the variation of NEE and its component fluxes, gross primary production (GPP and ecosystem respiration (Re, with the aim to clarify how climatic factors controlled the site's carbon balance. The young plantation acted as a relatively strong sink for CO2 during all of the three years, with an annual net sequestration of −102, −154, and −67 g C m−2 for 2004, 2005, and 2006, respectively. This variation was more related to variation in carbon efflux (Re than carbon uptake (GPP. The abiotic factors that showed the strongest correlation to Re were air temperature during the growing season and soil water potential. The GPP mostly followed the seasonal pattern in irradiance, except in 2005, when the plantation experienced severe spring frost damage that set the GPP back to zero. It was not expected that the rather slow-growing Siberian larch plantation would be such a strong sink for atmospheric CO2 only twelve years after site preparation and afforestation.

  3. Using Eddy Covariance Sensors to Quantify Carbon Metabolism of Peatlands: A Case Study in Turkey

    Directory of Open Access Journals (Sweden)

    Can Ertekin

    2011-01-01

    Full Text Available Net ecosystem exchange (NEE of carbon dioxide (CO2 was measured in a cool temperate peatland in northwestern Turkey on a continuous basis using eddy covariance (EC sensors and multiple (non-linear regression-M(NLR-models. Our results showed that hourly NEE varied between −1.26 and 1.06 mg CO2 m−2 s−1, with a mean value of 0.11 mg CO2 m−2 s−1. Nighttime ecosystem respiration (RE was on average measured as 0.23 ± 0.09 mg CO2 m−2 s−1. Two best-fit M(NLR models estimated daytime RE as 0.64 ± 0.31 and 0.24 ± 0.05 mg CO2 m−2 s−1. Total RE as the sum of nighttime and daytime RE ranged from 0.47 to 0.87 mg CO2 m−2 s−1, thus yielding estimates of gross primary productivity (GPP at −0.35 ± 0.18 and −0.74 ± 0.43 mg CO2 m−2 s−1. Use of EC sensors and M(NLR models is one of the most direct ways to quantify turbulent CO2 exchanges among the soil, vegetation and atmosphere within the atmospheric boundary layer, as well as source and sink behaviors of ecosystems.

  4. Spatiotemporal variations in growing season exchanges of CO2, H2O,and sensible heat in agricultural fields of the Southern GreatPlains

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Marc L.; Billesbach, David P.; Berry, Joseph A.; Riley,William J.; Torn, Margaret S.

    2007-06-13

    Climate, vegetation cover, and management create fine-scaleheterogeneity in unirrigated agricultural regions, with important but notwell-quantified consequences for spatial and temporal variations insurface CO2, water, and heat fluxes. We measured eddy covariance fluxesin seven agricultural fields--comprising winter wheat, pasture, andsorghum--in the U.S. Southern Great Plains (SGP) during the 2001-2003growing seasons. Land-cover was the dominant source of variation insurface fluxes, with 50-100 percent differences between fields planted inwinter-spring versus fields planted in summer. Interannual variation wasdriven mainly by precipitation, which varied more than two-fold betweenyears. Peak aboveground biomass and growing-season net ecosystem exchange(NEE) of CO2 increased in rough proportion to precipitation. Based on apartitioning of gross fluxes with a regression model, ecosystemrespiration increased linearly with gross primary production, but with anoffset that increased near the time of seed production. Because theregression model was designed for well-watered periods, it successfullyretrieved NEE and ecosystem parameters during the peak growing season,and identified periods of moisture limitation during the summer. Insummary, the effects of crop type, land management, and water limitationon carbon, water, and energy fluxes were large. Capturing the controllingfactors in landscape scale models will be necessary to estimate theecological feedbacks to climate and other environmental impactsassociated with changing human needs for agricultural production of food,fiber, and energy.

  5. JENIS TINDAK TUTUR YANG MENGIKUTI INTERJEKSI PANGGILAN DALAM BAHASA JEPANG

    Directory of Open Access Journals (Sweden)

    Maharani Patria Ratna

    2016-03-01

    Full Text Available [Types of Speech Acts Following Calling Interjection In Japanese] In speaking, there are times when a calling interjection can be followed by more than one type of speech acts. This research discusses the calling interjection which are used by male speakers in the film Brother Beat. In addition, this study also discussed what kind of speech acts that may follow the call in a speech interjection. The data in this study is a narrative that contains interjection calling spoken by male speakers in the Brother Beat movie. The method used is descriptive qualitative method. To get the data, the researcher usesscrutinize technique and tapping notes method. The results obtained in this research are, calling interjection, such as Anosa, oi, Anona, nee, you, and ano, are often used by male speakers to call the addressees. After the calling interjection, directive speech act and assertive speech act are speech act which appear to follow the calling interjection. Interjection ano sa, oi, anona, and ano, are types of calling interjection which can be followed by a directive speech acts and assertive speech act. In the other hand, calling interjection of nee, can be only  followed by a directive speech act, while calling interjection of you can be followed by a ssertives speech act.

  6. Investigating the Effect of Soil Moisture on Net Ecosystem Exchange in Shale Hills

    Science.gov (United States)

    Griffiths, Z. G.; Davis, K. J.; He, Y.

    2016-12-01

    Carbon sinks have the ability to absorb more carbon dioxide than what they emit. The terrestrial biome acts as a huge carbon sink, however, this ability is dependent on different environmental factors. This study focused on the effects of soil moisture on net ecosystem exchange(NEE) in the Shale Hills Critical Zone Observatory, PA. It was hypothesized that the strength of the carbon sink would grow with wetter soils. Data was collected from the eddy-covariance flux tower, a COSMOS soil moisture probe, automated soil respiration chambers and sap flow probes for May to August between the years 2011-2016. Since temperature and photosynthetically active radiation(PAR) also have an effect on carbon fluxes, these variables were isolated to properly study soil moisture and carbon fluxes. Generally, less carbon dioxide was absorbed with increasing soil moisture. Since NEE is a combination of photosynthesis and respiration, the effect of soil moisture was studied separately for each process. The sap flow data showed a decrease in activity with increasing soil moisture, hence photosynthesis was most likely reduced. Additionally, more carbon dioxide was emitted from respiration with increasing soil moisture. These findings could possibly explain why the forest at Shale Hills tends to release more carbon dioxide with increasing soil moisture.

  7. Partitioning CO2 fluxes with isotopologue measurements and modeling to understand mechanisms of forest carbon sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, Eric A. [Woods Hole Research Center, Falmouth, MA (United States); Saleska, Scott [Univ. of Arizona, Tucson, AZ (United States); Savage, Kathleen [Woods Hole Research Center, Falmouth, MA (United States); Finzi, Adrien [Boston Univ., MA (United States); Moorcroft, Paul [Harvard Univ., Cambridge, MA (United States); Wehr, Richard [Univ. of Arizona, Tucson, AZ (United States)

    2016-02-18

    1. Project Summary and Objectives This project combines automated in situ observations of the isotopologues of CO2 with root observations, novel experimental manipulations of belowground processes, and isotope-enabled ecosystem modeling to investigate mechanisms of below- vs. aboveground carbon sequestration at the Harvard Forest Environmental Measurements Site (EMS). The proposed objectives, which have now been largely accomplished, include: A. Partitioning of net ecosystem CO2 exchange (NEE) into photosynthesis and respiration using long-term continuous observations of the isotopic composition of NEE, and analysis of their dynamics ; B. Investigation of the influence of vegetation phenology on the timing and magnitude of carbon allocated belowground using measurements of root growth and indices of belowground autotrophic vs. heterotrophic respiration (via trenched plots and isotope measurements); C. Testing whether plant allocation of carbon belowground stimulates the microbial decomposition of soil organic matter, using in situ rhizosphere simulation experiments wherein realistic quantities of artificial isotopically-labeled exudates are released into the soil; and D. Synthesis and interpretation of the above data using the Ecosystem Demography Model 2 (ED2).

  8. Partitioning CO2 fluxes with isotopologue measurements and modeling to understand mechanisms of forest carbon sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Saleska, Scott [Univ. of Arizona, Tucson, AZ (United States). Dept. of Ecology and Evolutionary Biology; Davidson, Eric [Woods Hole Research Center, Falmouth, MA (United States); Finzi, Adrien [Boston Univ., MA (United States). Dept. of Biology; Wehr, Richard [Univ. of Arizona, Tucson, AZ (United States); Moorcroft, Paul [Harvard Univ., Cambridge, MA (United States). Dept. of Organismic and Evolutionary Biology

    2016-01-28

    This project combines automated in situ observations of the isotopologues of CO2 with root observations, novel experimental manipulations of below ground processes, and isotope-enabled ecosystem modeling to investigate mechanisms of below- vs. above ground carbon sequestration at the Harvard Forest Environmental Measurements Site (EMS). The proposed objectives, which have now been largely accomplished, include: (A) Partitioning of net ecosystem CO2 exchange (NEE) into photosynthesis and respiration using long-term continuous observations of the isotopic composition of NEE, and analysis of their dynamics; (B) Investigation of the influence of vegetation phenology on the timing and magnitude of carbon allocated below ground using measurements of root growth and indices of below ground autotrophic vs. heterotrophic respiration (via trenched plots andisotope measurements); (C) Testing whether plant allocation of carbon below ground stimulates the microbial decomposition of soil organic matter, using in situ rhizosphere simulation experiments wherein realistic quantities of artificial isotopically-labeled exudates are released into the soil; and (D) Synthesis and interpretation of the above data using the Ecosystem Demography Model 2 (ED2).

  9. Epiderme e padrão de venação foliar de espécies de Lauraceae Epiderm and leaf venation pattern of Lauraceae species

    Directory of Open Access Journals (Sweden)

    Pedro Luís Rodrigues de Moraes

    1999-04-01

    Full Text Available São descritas as características da epiderme e do padrão de venação foliar de eófilos e nomófilos de Cryptocarya moschata Nees, Endlicheria paniculata (Spreng. MacBride e Ocotea catharinensis Mez. Tanto C. moschata, como O. catharinensis, mostraram variação considerável no grau de sinuosidade das paredes celulares anticlinais e na venação foliar microscópica de nomófilos, dificultando o uso destes caracteres para fins taxonômicos.The epidermal and leaf venation pattern of eophylls and nomophylls of Ctyptocarya moschata Nees, Endlicheria paniculata (Spreng. MacBride, and Ocotea catharinensis Mez are described. Both C. moschata and O. catharinensis presented a pronounced variation in the rate of ondulation in the anticlinal cell walls as well as in the minor venation of nomophylls. This makes it difficult to use these features for taxonomical purposes.

  10. The SMAP Level 4 Carbon PRODUCT for Monitoring Terrestrial Ecosystem-Atmosphere CO2 Exchange

    Science.gov (United States)

    Jones, L. A.; Kimball, J. S.; Madani, N.; Reichle, R. H.; Glassy, J.; Ardizzone, J/

    2016-01-01

    The NASA Soil Moisture Active Passive (SMAP) mission Level 4 Carbon (L4_C) product provides model estimates of Net Ecosystem CO2 exchange (NEE) incorporating SMAP soil moisture information as a primary driver. The L4_C product provides NEE, computed as total respiration less gross photosynthesis, at a daily time step and approximate 14-day latency posted to a 9-km global grid summarized by plant functional type. The L4_C product includes component carbon fluxes, surface soil organic carbon stocks, underlying environmental constraints, and detailed uncertainty metrics. The L4_C model is driven by the SMAP Level 4 Soil Moisture (L4_SM) data assimilation product, with additional inputs from the Goddard Earth Observing System, Version 5 (GEOS-5) weather analysis and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data. The L4_C data record extends from March 2015 to present with ongoing production. Initial comparisons against global CO2 eddy flux tower measurements, satellite Solar Induced Canopy Florescence (SIF) and other independent observation benchmarks show favorable L4_C performance and accuracy, capturing the dynamic biosphere response to recent weather anomalies and demonstrating the value of SMAP observations for monitoring of global terrestrial water and carbon cycle linkages.

  11. Predicting duration of mechanical ventilation in patients with carbon monoxide poisoning: a retrospective study.

    Science.gov (United States)

    Shen, Chih-Hao; Peng, Chung-Kan; Chou, Yu-Ching; Pan, Ke-Ting; Chang, Shun-Cheng; Chang, Shan-Yueh; Huang, Kun-Lun

    2015-02-01

    Patients with severe carbon monoxide (CO) poisoning may develop acute respiratory failure, which needs endotracheal intubation and mechanical ventilation (MV). The objective of this study was to identify the predictors for duration of MV in patients with severe CO poisoning and acute respiratory failure. This is a retrospective observational study of 796 consecutive patients diagnosed with acute CO poisoning that presented to the emergency department. Patients who received MV were divided into 2 groups: the early extubation (EE) consisting of patients who were on MV for less than 72 hours and the nonearly extubation (NEE) consisting of patients who were on MV for more than 72 hours. Demographic and clinical data of the two groups were extracted for analysis. The intubation rate of all CO-poisoned patients was 23.4%. A total of 168 patients were enrolled in this study. The main source of CO exposure was intentional CO poisoning by charcoal burning (137 patients). Positive toxicology screening result was found in 104 patients (61.9%). The EE group had 105 patients (62.5%). On arriving at the emergency department, high incidence of hypotension; high white blood cell count; and elevation of blood urea nitrogen, creatinine, aspartate aminotransferase, alanine aminotransferase, creatine kinase, and troponin-I levels were statistically significant in the NEE group (P poisoning and acute respiratory failure. On the other hand, elevation of initial troponin-I level is a predictor for a longer duration of MV. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Estimating carbon flux phenology with satellite-derived land surface phenology and climate drivers for different biomes: a synthesis of AmeriFlux observations.

    Directory of Open Access Journals (Sweden)

    Wenquan Zhu

    Full Text Available Carbon Flux Phenology (CFP can affect the interannual variation in Net Ecosystem Exchange (NEE of carbon between terrestrial ecosystems and the atmosphere. In this study, we proposed a methodology to estimate CFP metrics with satellite-derived Land Surface Phenology (LSP metrics and climate drivers for 4 biomes (i.e., deciduous broadleaf forest, evergreen needleleaf forest, grasslands and croplands, using 159 site-years of NEE and climate data from 32 AmeriFlux sites and MODIS vegetation index time-series data. LSP metrics combined with optimal climate drivers can explain the variability in Start of Carbon Uptake (SCU by more than 70% and End of Carbon Uptake (ECU by more than 60%. The Root Mean Square Error (RMSE of the estimations was within 8.5 days for both SCU and ECU. The estimation performance for this methodology was primarily dependent on the optimal combination of the LSP retrieval methods, the explanatory climate drivers, the biome types, and the specific CFP metric. This methodology has a potential for allowing extrapolation of CFP metrics for biomes with a distinct and detectable seasonal cycle over large areas, based on synoptic multi-temporal optical satellite data and climate data.

  13. Snow damage strongly reduces the strength of the carbon sink in a primary subtropical evergreen broadleaved forest

    Science.gov (United States)

    Song, Qing-Hai; Fei, Xue-Hai; Zhang, Yi-Ping; Sha, Li-Qing; Wu, Chuan-Sheng; Lu, Zhi-Yun; Luo, Kang; Zhou, Wen-Jun; Liu, Yun-Tong; Gao, Jin-Bo

    2017-10-01

    A primary subtropical evergreen broadleaved forest in southwest China experienced a particularly extreme snowfall event during January 2015. The 2015 event enabled the quantification of the impact of the extreme meteorological event on the forest carbon balance. We analyzed five years of continuous measurements of CO2 exchange across the biosphere/atmosphere interface in the forest using an eddy covariance technique. We quantified how exposure to an extreme meteorological event affected ecosystem processes that determine gross primary productivity (GPP) and ecosystem respiration (R eco), and thus annual net carbon (C) sequestration. The forest canopy was severely damaged by the heavy snow, and the leaf area index (LAI) decreased significantly from January to July 2015. GPP, net ecosystem exchange (NEE), and R eco all sharply decreased in 2015 after the heavy snow. On average, a strong decrease of 544 g C m‑2 year‑1 in annual NEE in 2015 was associated with a decrease of 829 g C m‑2 year‑1 in annual GPP and a decrease of 285 g C m‑2 year‑1 in annual R eco. Overall, annual net C uptake in 2015 was reduced by 76% compared to the mean C uptake of the previous four years. A sharp increase in carbon uptake was also observed in 2016, indicating that long-term, continuous measurements should be carried out to evaluate the overall response to the disturbance.

  14. Phylogenetic study of Oryzoideae species and related taxa of the Poaceae based on atpB-rbcL and ndhF DNA sequences.

    Science.gov (United States)

    Zeng, Xu; Yuan, Zhengrong; Tong, Xin; Li, Qiushi; Gao, Weiwei; Qin, Minjian; Liu, Zhihua

    2012-05-01

    Oryzoideae (Poaceae) plants have economic and ecological value. However, the phylogenetic position of some plants is not clear, such as Hygroryza aristata (Retz.) Nees. and Porteresia coarctata (Roxb.) Tateoka (syn. Oryza coarctata). Comprehensive molecular phylogenetic studies have been carried out on many genera in the Poaceae. The different DNA sequences, including nuclear and chloroplast sequences, had been extensively employed to determine relationships at both higher and lower taxonomic levels in the Poaceae. Chloroplast DNA ndhF gene and atpB-rbcL spacer were used to construct phylogenetic trees and estimate the divergence time of Oryzoideae, Bambusoideae, Panicoideae, Pooideae and so on. Complete sequences of atpB-rbcL and ndhF were generated for 17 species representing six species of the Oryzoideae and related subfamilies. Nicotiana tabacum L. was the outgroup species. The two DNA datasets were analyzed, using Maximum Parsimony and Bayesian analysis methods. The molecular phylogeny revealed that H. aristata (Retz.) Nees was the sister to Chikusichloa aquatica Koidz. Moreover, P. coarctata (Roxb.) Tateoka was in the genus Oryza. Furthermore, the result of evolution analysis, which based on the ndhF marker, indicated that the time of origin of Oryzoideae might be 31 million years ago.

  15. Light-stress avoidance mechanisms in a Sphagnum-dominated wet coastal Arctic tundra ecosystem in Alaska.

    Science.gov (United States)

    Zona, D; Oechel, Walter C; Richards, James H; Hastings, Steven; Kopetz, Irene; Ikawa, Hiroki; Oberbauer, Steven

    2011-03-01

    The Arctic experiences a high-radiation environment in the summer with 24-hour daylight for more than two months. Damage to plants and ecosystem metabolism can be muted by overcast conditions common in much of the Arctic. However, with climate change, extreme dry years and clearer skies could lead to the risk of increased photoxidation and photoinhibition in Arctic primary producers. Mosses, which often exceed the NPP of vascular plants in Arctic areas, are often understudied. As a result, the effect of specific environmental factors, including light, on these growth forms is poorly understood. Here, we investigated net ecosystem exchange (NEE) at the ecosystem scale, net Sphagnum CO2 exchange (NSE), and photoinhibition to better understand the impact of light on carbon exchange from a moss-dominated coastal tundra ecosystem during the summer season 2006. Sphagnum photosynthesis showed photoinhibition early in the season coupled with low ecosystem NEE. However, later in the season, Sphagnum maintained a significant CO2 uptake, probably for the development of subsurface moss layers protected from strong radiation. We suggest that the compact canopy structure of Sphagnum reduces light penetration to the subsurface layers of the moss mat and thereby protects the active photosynthetic tissues from damage. This stress avoidance mechanism allowed Sphagnum to constitute a significant percentage (up to 60%) of the ecosystem net daytime CO2 uptake at the end of the growing season despite the high levels of radiation experienced.

  16. Estilos interactivos de educadoras do Ensino Especial em contexto de educação-de-infância

    Directory of Open Access Journals (Sweden)

    Catarina Grande

    Full Text Available Este estudo pretendeu caracterizar os estilos interactivos das educadoras do Ensino Especial ao se relacionarem com crianças com Necessidades Educativas Especiais (NEE integradas em creches/jardins-de-infância do Porto. Participaram 50 educadoras e 50 crianças. Os comportamentos interactivos foram avaliados utilizando a Escala de Avaliação dos Estilos de Ensino. O envolvimento das crianças foi codificado por meio do EQUAL-III. A análise de clusters identificou dois sub-grupos: (i educadoras que utilizam mais frequentemente comportamentos directivos; (ii educadoras nas quais predominam comportamentos elaborativos e responsivos. Os subgrupos distinguiram-se em características de qualidade estrutural da sala, da educadora e do envolvimento da criança. As crianças com NEE parecem se beneficiar de interacções baixas em directividade. Interacções elaborativas-responsivas tendem a promover níveis mais sofisticados de envolvimento, pelo que são recomendadas.

  17. Coleopterans associated with plants that form phytotelmata in subtropical and temperate Argentina, South America.

    Science.gov (United States)

    Campos, Raúl E; Fernández, Liliana A

    2011-01-01

    A list of the most common plants that form phytotelmata and their associated coleopterans (aquatic, semi-aquatic and terrestrial) from the northeastern subtropical and temperate area of Argentina, South America with biological and behavioral observations is presented in this study. Species of Poaceae (n = 3), Bromeliaceae (5), Apiaceae (6), Araceae (2), Urticaceae (1), Marantaceae (1), Arecaceae (1), Dipsacaceae (1) and Cyperaceae (1) were identified as phytotelmata. Aquatic species of Scirtidae (2), Dytiscidae (2), and Hydrophilidae (4), semi-aquatic Chelonariidae (2), and terrestrial species of Carabidae (3), Staphylinidae (5), Histeridae (1), Elateridae (1), Cantharidae (1), Cleridae (1), Tenebrionidae (1), Meloidae (1), Anthicidae (1), Chrysomelidae (3), Curculionidae (7) and Apionidae (1) were identified from six species of Eryngium L. (Apiales: Apiaceae), two species of Guadua Kunth (Poales: Poaceae), Aechmea distichantha Lemaire (Poales: Bromeliaceae), and from fallen leaves of Euterpe edulis Martius (Arecales: Arecaceae) from the temperate and subtropical area. The highest species richness was recorded in Eryngium phytotelmata. Fifteen species of beetles inhabit Eryngium cabrerae Pontiroli, 11 in E. horridum Malme, 7 in E. stenophyllum Urban, 4 in E. aff. serra Chamisso and Schlechtendal., 3 in E. elegans Chamisso and Schlechtendal, 2 in E. eburneum Decne and E. pandanifolium Chamisso and Schlechtendal. From bamboo, 6 species of coleopterans were collected from Guadua trinii (Nees) Nees ex Ruprecht and 4 from G. chacoensis (Rojas) Londoño and Peterson. Three species of aquatic coleopterans were recorded from A. distichantha and only one from E. edulis.

  18. Relation of Chlorophyll Fluorescence Sensitive Reflectance Ratios to Carbon Flux Measurements of Montanne Grassland and Norway Spruce Forest Ecosystems in the Temperate Zone

    Directory of Open Access Journals (Sweden)

    Alexander Ač

    2012-01-01

    Full Text Available We explored ability of reflectance vegetation indexes (VIs related to chlorophyll fluorescence emission (686/630, 740/800 and de-epoxidation state of xanthophyll cycle pigments (PRI, calculated as (531−570/(531−570 to track changes in the CO2 assimilation rate and Light Use Efficiency (LUE in montane grassland and Norway spruce forest ecosystems, both at leaf and also canopy level. VIs were measured at two research plots using a ground-based high spatial/spectral resolution imaging spectroscopy technique. No significant relationship between VIs and leaf light-saturated CO2 assimilation (MAX was detected in instantaneous measurements of grassland under steady-state irradiance conditions. Once the temporal dimension and daily irradiance variation were included into the experimental setup, statistically significant changes in VIs related to tested physiological parameters were revealed. ΔPRI and Δ(686/630 of grassland plant leaves under dark-to-full sunlight transition in the scale of minutes were significantly related to MAX (2=0.51. In the daily course, the variation of VIs measured in one-hour intervals correlated well with the variation of Gross Primary Production (GPP, Net Ecosystem Exchange (NEE, and LUE estimated via the eddy-covariance flux tower. Statistical results were weaker in the case of the grassland ecosystem, with the strongest statistical relation of the index 686/630 with NEE and GPP.

  19. Curricular adaptation: alternatives of pedagogical support in the inclusive education

    Directory of Open Access Journals (Sweden)

    Lucia Pereira Leite

    2010-12-01

    Full Text Available The organization of the inclusive education is a slow and complex process, which has the necessity of investments in supports for all the scholar team. Aiming at spreading one of the actions carried out for the promotion of the inclusive educational practices in a municipal education system in a western city in the state of São Paulo, this paperwork has the objective of presenting an elaborated manual of orientations for the implementation of the individual curricular adaptations (ACIs for students who demand special educational necessities.(NEEs. The material was constituted on the basis of three data sets: 1 tabulation of the evaluations of the curricular adaptations already made; 2 the literature review; 3 analysis of the themes which have emerged during case discussion meetings mediated by the researchers with teachers from the Specialized Pedagogical Support Service (SAPE, with teachers and administrators from the common education system and the technical-pedagogical team. The final version of the manual contemplates the theoretical-operational aspects about the themes: flexibility and curricular adequation, inclusive education, definitions of NEEs, how SAPE works; and it finishes with a model proposal of ACI. It is expected that the spreading of this material can subside new curricular propositions for students with deficiency that are very distant from the academic level expected for the current scholar year.

  20. The Degree of Permafrost Thawing Determines Arctic Tundra Carbon Balance

    Science.gov (United States)

    Vogel, J. G.; Schuur, E. A.; Sickman, J.; Lee, H.; Trucco, C.

    2007-12-01

    In interior Alaska, we measured gross photosynthesis (GP), ecosystem respiration (ER), and net ecosystem exchange (NEE) near a permafrost monitoring borehole that has recorded an increase in permafrost temperatures during the last 22 years. From May 2004 to May 2006, ecosystem C exchange measurements were made with static and automatic chambers in a moist acidic tundra ecosystem. A gradient in degree of permafrost thaw was used to select three sites (Minimal, Moderate and Severe Thaw) that corresponded to an increase in thermokarst occurrence. Between June 1 and August 30, the Severe and Moderate Thaw sites had significantly greater C uptake (GPP) (pproductivity. However, greater winter ER from the Severe Thaw site caused it to be a source (negative NEE, -128 g C m-2) of carbon over three years. The Moderate Thaw site was a carbon sink (52 g C m- 2), while the Minimal Thaw site was near carbon neutral (-7 g C m-2). In the spring and fall, carbon uptake correlated with the occurrence of plant functional groups (sedges, evergreen shrubs) that maintain green foliage and can photosynthesize under cold conditions. Both of these functional groups decreased inside thermokarst. In the winter, the Severe Thaw site lost 34% more C than the other two sites, likely due to warmer deep soil temperatures. As permafrost thaw proceeds, increasing ecosystem C loss may occur during the winter, spring, and fall due to the unique biotic and abiotic characteristics of thermokarst.

  1. Bayesian optimization of modeled CO2 fluxes in Oregon using a dense tower network, aircraft campaigns, and the community land model 4.5

    Science.gov (United States)

    Schmidt, A.; Conley, S. A.; Goeckede, M.; Andrews, A. E.; Masarie, K. A.; Sweeney, C.

    2015-12-01

    Modeled estimates of net ecosystem exchange (NEE) calculated with CLM4.5 at 4 km horizontal resolution were optimized using a classical Bayesian inversion approach with atmospheric mixing ratio observations from a dense tower network in Oregon. We optimized NEE in monthly batches for the years 2012 through 2014, and determined the associated reduction in flux uncertainties broken up by sub-domains. The WRF-STILT transport model was deployed to link modelled fluxes of CO2 to the concentrations from 5 high precision and accuracy CO2 observation towers equipped with CRDS analyzers. To find the best compromise between aggregation errors and the degrees of freedom in the system, we developed an approach for the spatial structuring of our domain that was informed by an unsupervised clustering approach based on flux values of the prior state vector and information about the land surface, soil, and vegetation distribution that was used in the model. To assess the uncertainty of the transport modeling component within our inverse optimization framework we used the data of 7 airborne measurement campaigns over the Oregon domain during the study period providing detailed information about the errors in the model boundary-layer height and wind field of the transport model. The optimized model was then used to estimate future CO2 budgets for Oregon, including potential effects of LULC changes from conventional agriculture towards energy crops.

  2. Variability in carbon exchange of European croplands

    DEFF Research Database (Denmark)

    Eddy J, Moors; Jacobs, Cor; Jans, Wilma

    2010-01-01

    as the standard deviation of these cropping periods was 251 gC m-2. These numbers do not include lateral inputs such as the carbon content of applied manure, nor the carbon exchange out of the cropping period. Both are expected to have a major effect on the C budget of high energy summer crops such as maize. NEE...... measured at these sites or reported at the NUTS2 level dataset of EUROSTAT is a relatively poor predictor of NEE. To investigate the difference in the variability in CO2 emissions of different crops at the same location and to compare this variation with the variation of the same crop at different...... locations and with the inter-annual variation the measured dataset at the flux sites was extended with simulated data. These simulations show that the variability in carbon exchange is determined by: firstly the choice of crop and the location and to a lesser extent by the yearly differences in climate....

  3. Index of Cultural Significance as a Potential Tool for Conservation of Plants Diversity by Communities in The Kerinci Seblat National Park

    Directory of Open Access Journals (Sweden)

    Asvic Helida

    2015-12-01

    Full Text Available The Kerinci community is an Indonesian indigenous people who live in Kerinci Regency, Jambi Province. They have local knowledge of the surrounding vegetation that has become a cultural unifying factor within the community. The study reported here aimed to analyze the importance of plants of particular cultural significance and to review efforts to conserve these plants based on Kerinci cultural values. The study was conducted for eight months from October 2013 to May 2014 at three locations chosen purposively, they were Lempur Baru Village, Lama Tamiai Village and Ulu Jernih Village. The data was obtained using a participatory observation approach, based on key informant interviews, while the assessment of plant distribution was based on a whole-of-community viewpoint. The research data consisted of data on the botany of the plants, on the utilization of the plants and on assessment of plant distribution. Analysis of data for 234 plant species used a formula for index of cultural significance (ICS adopted from Turner (1988. The study showed that rice (Oryza sativa L. and cinnamon (Cinnamomum burmanni (Nees & T.Nees Blume are important plant species with values for the Cultural Index of 59 and 57 respectively, while the species known as 'inggu' (Ruta angustifolia (L. Pers had the lowest ICS, of 3. The 'Tri-Stimulus Amar' conservation analysis developed by Zuhud (2007 is seen as a useful model for considering the cultural values that motivate the Kerinci community's plant conservation actions.

  4. El efecto de los cursos con las TIC en el funcionamiento y bienestar social

    Directory of Open Access Journals (Sweden)

    Deisy Acosta Ham

    2010-04-01

    Full Text Available Cuando se es madre de un niño con necesidades educativas especiales (NEE, se vive una serie de etapas negativas que afectan a toda la familia, pero significativamente al niño especial, cuando no se dispone de la orientación y ayuda adecuadas. Las madres, al brindar atención de tiempo completo a su hijo con NEE, hacen infuncionales sus relaciones sociales; en otras palabras, sus escalas de función y bienestar social, relacionadas con la salud, son afectadas de modo negativo. Las tecnologías de información y comunicación (TIC aparecen en este escenario para brindar información y apoyo con programas educativos, comunidades virtuales, foros, y canales de conversación que proporcionan servicios psicopedagógicos, terapia, cursos de orientación, crecimiento personal y profesional. Las TIC otorgan ayuda inmediata, comunicación y acceso a información ilimitada. ¿Cómo saber si estas tecnologías están teniendo algún efecto en el aspecto social de las madres? De ahí que el propósito del presente trabajo sea conocer si existe o no dicho efecto.

  5. Fault distribution to the west of Songliao Basin by means of gravity analysis

    Science.gov (United States)

    Chen, Jun; Li, Shizhen; Zhou, Xingui

    2017-04-01

    Our study area is located to the west of Songliao Basin, northeastern China. Its tectonic setting includes three parts, the Argun block, the Higgnan block and the Songnen block from north to south. It belongs to the northeastern Asia orogenic zone surrounded by the Siberia plate, the North China plate and the Pacific plate. As the global feature, the gravity anomaly values increase from west to east, and from southwest to northeast. The minimum value is 5mGal, and the maximum value is 5mGal. In the southwestern region, the variation range is from -87mGal to 65mGal. But in the northeastern region, it is between -65mGal and 55mGal. In the central region, the gravity anomaly values are between -55mGal and 25mGal, and the gravity anomaly gradient is bigger than that in other regions. In the eastern region, gravity anomaly values are bigger than those in other regions, and the gravity anomaly characteristics is complicated. There are gravity anomaly gradient belts, anomaly direction changes, distortion of contour lines, broaden or narrowed of the closed contour lines. Gravity anomaly data can be used for study of tectonics division and regional geological structures. The gravity anomaly data has been processed using many methods. Firstly, analytic upward- continuation and apparent-depth filtering were used to separate the gravity anomaly field with different depth and different scale. Then, horizontal derivatives, vertical derivatives, analytical signal calculation, small sub-domain filtering were used to increase the gravity resolution for fault discrimination. Through the interpretation of different depth and different scale gravity anomalies, we mapped the fault distribution of the study area. There are four types of faults with different trends, which are north east-east(NEE), near west-east(WE), north-east(NE) and north-west(NW). The NE and NW trending faults are distributed in the whole region. The WE trending faults are located mainly in the southern region of

  6. Net ecosystem CO2 exchange and evapotranspiration of a sphagnum mire: field measurements and model simulations

    Science.gov (United States)

    Olchev, Alexander; Volkova, Elena; Karataeva, Tatiana; Zatsarinnaya, Dina; Novenko, Elena

    2014-05-01

    The spatial and temporal variability of net ecosystem exchange of CO2 (NEE) and evapotranspiration (ET) of a karst-hole sphagnum peat mire situated at the boundary between broad-leaved and forest-steppe zones in the central part of European Russia (54.06N, 37.59E, 260 m a.s.l.) was described using results of field measurements and simulations with Mixfor-3D model. The area of the mire is about 1.2 ha and it is surrounded by a broadleaved forest stand. It is a typical peat mire according to water and mineral supply as well as to vegetation composition. The vegetation of the peripheral parts of the mire is typical eutrophic whereas the vegetation in its central part is represented by meso-oligothrophic plant communities. To describe the spatial variability of NEE and ET within the mire a portable measuring system consisting of a transparent ventilated chamber combined with an infrared CO2 and H2O analyzer LI-840A (Li-Cor, USA) was used. The measurements were provided along a transect from the southern peripheral part of the mire to its center under sunny clear-sky weather conditions in the period from May to September of 2012 and from May 2013 to October 2013. The chamber method was used for measurements of NEE and ET fluxes because of small size of the mire, a very uniform surrounding forest stand and the mosaic mire vegetation. All these factors promote very heterogeneous exchange conditions within the mire and make it difficult to apply, for example, an eddy covariance method that is widely used for flux measurements in the field. The results of the field measurements showed a significant spatial and temporal variability of NEE and ET that was mainly influenced by incoming solar radiation, air temperature and ground water level. During the entire growing season the central part of the mire was a sink of CO2 for the atmosphere (up to 6.8±4.2 µmol m-2 s-1 in June) whereas its peripheral part, due to strong shading by the surrounding forest, was mainly a source of

  7. Net ecosystem exchange from two vegetation communities in Coppermine Peninsula, Maritime Antarctica

    Science.gov (United States)

    Thomazini, André; Francelino, Márcio; Pereira, Antônio; Schünemann, Adriano; Mendonça, Eduardo Sá; Michel, Roberto; Schaefer, Carlos

    2017-04-01

    Antarctic vegetation frequently changes its constitution, size and distribution across the landscape, playing a key role on the nutrient cycling. The carbon cycling and land-atmosphere exchanges under these dynamic conditions remains little studied. The objective of this study was to evaluate the net ecosystem exchange (NEE), based on in situ measurements from different vegetation communities in Coppermine Peninsula, Maritime Antarctica. Mosses patches cover 1.5 ha, representing one of the most important cryptogamic communities in Maritime Antarctica. Two typical vegetation communities were studied: a moss site (hereafter Site 1) and a moss/lichen site (hereafter Site 2). Site 1 represents a low lying marine terrace (20 m asl), highly influenced by ice/snow/permafrost melting from the uplands, mainly constituted by Sanionia uncinata (Hedw.) Loeske, forming a dense carpet with 3-7 cm thickness. Site 2 is located in an elevated basalt ridge (29 m a.s.l.), under local influence of permafrost within 30 cm depth. Vegetation composition is varied , with a dominance of Polytrichastrum alpinum G.L. Smith, and lichens (Psoroma cinnamomeum Malme, Ochrolechia frigida (Sw.). To obtain the NEE data, we used closed automatic chamber system of CO2 exchange (LI-COR Biosciences, Lincoln, NE, USA) containing an infra-red gas analyzer (model LI-8100A), a multiplexer system (model LI-8150) and one clear chamber (model LI-8100-104C). Three PVC soil collars of 20 cm diameter were placed into the soil prior measurements at each selected site (standard depth of 3 cm), spaced 2 m from each other. NEE at each point were based on a single measurement over 1.5 min, and the concentrations of CO2 were determined at 3 sec intervals to determinate the current flux of CO2. Mean values of NEE were obtained from 08th (00:00 h) to January 22th, 2016 (12:00 h). From January 08th to 22th, mean values of NEE were -0.54 (±0.05) μmol CO2 m-2 s-1 in Site 1 and -0.07 (±0.02) μmol CO2 m-2 s-1 in Site 2

  8. Influence of soil C stocks and interannual climatic variability on the CO2 and CH4 exchange of maize cultivated on mineral and organic soils in NE Germany

    Science.gov (United States)

    Pohl, Madlen; Hagemann, Ulrike; Hoffmann, Mathias; Giebels, Michael; Albiac-Borraz, Elisa; Sommer, Michael; Augustin, Jürgen

    2014-05-01

    Due to its glacially influenced genesis and land use history, the soils of the Great Plain Region of NE-Germany show large differences in groundwater levels and soil carbon (C) stocks over short distances. Although generally featuring a rather dry climate, trace gas exchange at individual sites may be influenced by i) interannual climatic variability, particularly with respect to precipitation; as well as by ii) variability of soil C stocks. However, it is still unclear how these factors affect fluxes of CO2 and CH4, and if there is any positive or negative feedback on the C source or sink function of different soil types. We present measured and modeled CO2 and CH4 fluxes of minerally fertilized grain maize for three sites located near Paulinenaue, within the so-called Rhin-Havelluch, a shallow and drained paludification mire complex in NE Germany. The sites are characterized by a distinct gradient of 0-1 m soil organic C stocks: i) Arenosol (AR: mineral soil/distant groundwater; 8 000 g C m-2), ii) Gleysol (GL: organic soil/groundwater-dependent; 35 000 g C m-2), and iii) Histosol (HS: organic soil/near groundwater; 45 000 g C m-2). CO2 flux measurements of ecosystem respiration (Reco), net ecosystem exchange (NEE) and gross primary production (GPP; calculated as difference between NEE and Reco) were conducted every four weeks using a flow-through non-steady-state closed chamber system. Measurement gaps of Reco and NEE were filled by using temperature or radiation-based models, respectively. CH4 fluxes were measured bi-weekly using a static closed chamber system with interval sampling, with gap filling via linear interpolation. Cumulated fluxes of CO2-C (Reco, GPP, NEE) and CH4-C were calculated for a period of four consecutive years (2007-2010). The intensity of CO2-C fluxes increased with growing soil organic C stocks (AR years 2008-2010 for Reco ranged between 1 500 g C m-2 and 2 000 g C m-2; annual GPP fluxes ranged from -1 400 g C m-2 to -2 300 g C m-2. NEE

  9. Hurricane disturbance and recovery of energy balance, CO2 fluxes and canopy structure in a mangrove forest of the Florida Everglades

    Science.gov (United States)

    Barr, Jordan G.; Engel, Vic; Smith, Thomas J.; Fuentes, Jose D.

    2012-01-01

    Eddy covariance (EC) estimates of carbon dioxide (CO2) fluxes and energy balance are examined to investigate the functional responses of a mature mangrove forest to a disturbance generated by Hurricane Wilma on October 24, 2005 in the Florida Everglades. At the EC site, high winds from the hurricane caused nearly 100% defoliation in the upper canopy and widespread tree mortality. Soil temperatures down to -50 cm increased, and air temperature lapse rates within the forest canopy switched from statically stable to statically unstable conditions following the disturbance. Unstable conditions allowed more efficient transport of water vapor and CO2 from the surface up to the upper canopy layer. Significant increases in latent heat fluxes (LE) and nighttime net ecosystem exchange (NEE) were also observed and sensible heat fluxes (H) as a proportion of net radiation decreased significantly in response to the disturbance. Many of these impacts persisted through much of the study period through 2009. However, local albedo and MODIS (Moderate Resolution Imaging Spectro-radiometer) data (the Enhanced Vegetation Index) indicated a substantial proportion of active leaf area recovered before the EC measurements began 1 year after the storm. Observed changes in the vertical distribution and the degree of clumping in newly emerged leaves may have affected the energy balance. Direct comparisons of daytime NEE values from before the storm and after our measurements resumed did not show substantial or consistent differences that could be attributed to the disturbance. Regression analyses on seasonal time scales were required to differentiate the storm's impact on monthly average daytime NEE from the changes caused by interannual variability in other environmental drivers. The effects of the storm were apparent on annual time scales, and CO2 uptake remained approximately 250 g C m-2 yr-1 lower in 2009 compared to the average annual values measured in 2004–2005. Dry season CO2

  10. A regional high-resolution carbon flux inversion of North America for 2004

    Directory of Open Access Journals (Sweden)

    A. E. Schuh

    2010-05-01

    Full Text Available Resolving the discrepancies between NEE estimates based upon (1 ground studies and (2 atmospheric inversion results, demands increasingly sophisticated techniques. In this paper we present a high-resolution inversion based upon a regional meteorology model (RAMS and an underlying biosphere (SiB3 model, both running on an identical 40 km grid over most of North America. Current operational systems like CarbonTracker as well as many previous global inversions including the Transcom suite of inversions have utilized inversion regions formed by collapsing biome-similar grid cells into larger aggregated regions. An extreme example of this might be where corrections to NEE imposed on forested regions on the east coast of the United States might be the same as that imposed on forests on the west coast of the United States while, in reality, there likely exist subtle differences in the two areas, both natural and anthropogenic. Our current inversion framework utilizes a combination of previously employed inversion techniques while allowing carbon flux corrections to be biome independent. Temporally and spatially high-resolution results utilizing biome-independent corrections provide insight into carbon dynamics in North America. In particular, we analyze hourly CO2 mixing ratio data from a sparse network of eight towers in North America for 2004. A prior estimate of carbon fluxes due to Gross Primary Productivity (GPP and Ecosystem Respiration (ER is constructed from the SiB3 biosphere model on a 40 km grid. A combination of transport from the RAMS and the Parameterized Chemical Transport Model (PCTM models is used to forge a connection between upwind biosphere fluxes and downwind observed CO2 mixing ratio data. A Kalman filter procedure is used to estimate weekly corrections to biosphere fluxes based upon observed CO2. RMSE-weighted annual NEE estimates, over an ensemble of potential inversion parameter sets, show a

  11. Patterns and controls of inter-annual variability in the terrestrial carbon budget

    Directory of Open Access Journals (Sweden)

    B. Marcolla

    2017-08-01

    Full Text Available The terrestrial carbon fluxes show the largest variability among the components of the global carbon cycle and drive most of the temporal variations in the growth rate of atmospheric CO2. Understanding the environmental controls and trends of the terrestrial carbon budget is therefore essential to predict the future trajectories of the CO2 airborne fraction and atmospheric concentrations. In the present work, patterns and controls of the inter-annual variability (IAV of carbon net ecosystem exchange (NEE have been analysed using three different data streams: ecosystem-level observations from the FLUXNET database (La Thuile and 2015 releases, the MPI-MTE (model tree ensemble bottom–up product resulting from the global upscaling of site-level fluxes, and the Jena CarboScope Inversion, a top–down estimate of surface fluxes obtained from observed CO2 concentrations and an atmospheric transport model. Consistencies and discrepancies in the temporal and spatial patterns and in the climatic and physiological controls of IAV were investigated between the three data sources. Results show that the global average of IAV at FLUXNET sites, quantified as the standard deviation of annual NEE, peaks in arid ecosystems and amounts to  ∼  120 gC m−2 y−1, almost 6 times more than the values calculated from the two global products (15 and 20 gC m−2 y−1 for MPI-MTE and the Jena Inversion, respectively. Most of the temporal variability observed in the last three decades of the MPI-MTE and Jena Inversion products is due to yearly anomalies, whereas the temporal trends explain only about 15 and 20 % of the variability, respectively. Both at the site level and on a global scale, the IAV of NEE is driven by the gross primary productivity and in particular by the cumulative carbon flux during the months when land acts as a sink. Altogether these results offer a broad view on the magnitude, spatial patterns and environmental drivers of IAV

  12. Toward verifying fossil fuel CO2 emissions with the CMAQ model: motivation, model description and initial simulation.

    Science.gov (United States)

    Liu, Zhen; Bambha, Ray P; Pinto, Joseph P; Zeng, Tao; Boylan, Jim; Huang, Maoyi; Lei, Huimin; Zhao, Chun; Liu, Shishi; Mao, Jiafu; Schwalm, Christopher R; Shi, Xiaoying; Wei, Yaxing; Michelsen, Hope A

    2014-04-01

    Motivated by the question of whether and how a state-of-the-art regional chemical transport model (CTM) can facilitate characterization of CO2 spatiotemporal variability and verify CO2 fossil-fuel emissions, we for the first time applied the Community Multiscale Air Quality (CMAQ) model to simulate CO2. This paper presents methods, input data, and initial results for CO2 simulation using CMAQ over the contiguous United States in October 2007. Modeling experiments have been performed to understand the roles of fossil-fuel emissions, biosphere-atmosphere exchange, and meteorology in regulating the spatial distribution of CO2 near the surface over the contiguous United States. Three sets of net ecosystem exchange (NEE) fluxes were used as input to assess the impact of uncertainty of NEE on CO2 concentrations simulated by CMAQ. Observational data from six tall tower sites across the country were used to evaluate model performance. In particular, at the Boulder Atmospheric Observatory (BAO), a tall tower site that receives urban emissions from Denver CO, the CMAQ model using hourly varying, high-resolution CO2 fossil-fuel emissions from the Vulcan inventory and Carbon Tracker optimized NEE reproduced the observed diurnal profile of CO2 reasonably well but with a low bias in the early morning. The spatial distribution of CO2 was found to correlate with NO(x), SO2, and CO, because of their similar fossil-fuel emission sources and common transport processes. These initial results from CMAQ demonstrate the potential of using a regional CTM to help interpret CO2 observations and understand CO2 variability in space and time. The ability to simulate a full suite of air pollutants in CMAQ will also facilitate investigations of their use as tracers for CO2 source attribution. This work serves as a proof of concept and the foundation for more comprehensive examinations of CO2 spatiotemporal variability and various uncertainties in the future. Atmospheric CO2 has long been modeled

  13. Eddy covariance flux measurements of net ecosystem carbon dioxide exchange from a lowland peatland flux tower network in England and Wales

    Science.gov (United States)

    Morrison, Ross; Balzter, Heiko; Burden, Annette; Callaghan, Nathan; Cumming, Alenander; Dixon, Simon; Evans, Jonathan; Kaduk, Joerg; Page, Susan; Pan, Gong; Rayment, Mark; Ridley, Luke; Rylett, Daniel; Worrall, Fred; Evans, Christopher

    2016-04-01

    Peatlands store disproportionately large amounts of soil carbon relative to other terrestrial ecosystems. Over recent decades, the large amount of carbon stored as peat has proved vulnerable to a range of land use pressures as well as the increasing impacts of climate change. In temperate Europe and elsewhere, large tracts of lowland peatland have been drained and converted to agricultural land use. Such changes have resulted in widespread losses of lowland peatland habitat, land subsidence across extensive areas and the transfer of historically accumulated soil carbon to the atmosphere as carbon dioxide (CO2). More recently, there has been growth in activities aiming to reduce these impacts through improved land management and peatland restoration. Despite a long history of productive land use and management, the magnitude and controls on greenhouse gas emissions from lowland peatland environments remain poorly quantified. Here, results of surface-atmosphere measurements of net ecosystem CO2 exchange (NEE) from a network of seven eddy covariance (EC) flux towers located at a range of lowland peatland ecosystems across the United Kingdom (UK) are presented. This spatially-dense peatland flux tower network forms part of a wider observation programme aiming to quantify carbon, water and greenhouse gas balances for lowland peatlands across the UK. EC measurements totalling over seventeen site years were obtained at sites exhibiting large differences in vegetation cover, hydrological functioning and land management. The sites in the network show remarkable spatial and temporal variability in NEE. Across sites, annual NEE ranged from a net sink of -194 ±38 g CO2-C m-2 yr-1 to a net source of 784±70 g CO2-C m-2 yr-1. The results suggest that semi-natural sites remain net sinks for atmospheric CO2. Sites that are drained for intensive agricultural production range from a small net sink to the largest observed source for atmospheric CO2 within the flux tower network

  14. The influence of warm-season precipitation on the diel cycle of the surface energy balance and carbon dioxide at a Colorado subalpine forest site

    Science.gov (United States)

    Burns, S. P.; Blanken, P. D.; Turnipseed, A. A.; Hu, J.; Monson, R. K.

    2015-12-01

    Precipitation changes the physical and biological characteristics of an ecosystem. Using a precipitation-based conditional sampling technique and a 14 year data set from a 25 m micrometeorological tower in a high-elevation subalpine forest, we examined how warm-season precipitation affected the above-canopy diel cycle of wind and turbulence, net radiation Rnet, ecosystem eddy covariance fluxes (sensible heat H, latent heat LE, and CO2 net ecosystem exchange NEE) and vertical profiles of scalars (air temperature Ta, specific humidity q, and CO2 dry mole fraction χc). This analysis allowed us to examine how precipitation modified these variables from hourly (i.e., the diel cycle) to multi-day time-scales (i.e., typical of a weather-system frontal passage). During mid-day we found the following: (i) even though precipitation caused mean changes on the order of 50-70 % to Rnet, H, and LE, the surface energy balance (SEB) was relatively insensitive to precipitation with mid-day closure values ranging between 90 and 110 %, and (ii) compared to a typical dry day, a day following a rainy day was characterized by increased ecosystem uptake of CO2 (NEE increased by ≈ 10 %), enhanced evaporative cooling (mid-day LE increased by ≈ 30 W m-2), and a smaller amount of sensible heat transfer (mid-day H decreased by ≈ 70 W m-2). Based on the mean diel cycle, the evaporative contribution to total evapotranspiration was, on average, around 6 % in dry conditions and between 15 and 25 % in partially wet conditions. Furthermore, increased LE lasted at least 18 h following a rain event. At night, even though precipitation (and accompanying clouds) reduced the magnitude of Rnet, LE increased from ≈ 10 to over 20 W m-2 due to increased evaporation. Any effect of precipitation on the nocturnal SEB closure and NEE was overshadowed by atmospheric phenomena such as horizontal advection and decoupling that create measurement difficulties. Above-canopy mean χc during wet conditions was

  15. The effect of warm-season precipitation on the diel cycle of the surface energy balance and carbon dioxide at a Colorado subalpine forest site

    Science.gov (United States)

    Burns, S. P.; Blanken, P. D.; Turnipseed, A. A.; Monson, R. K.

    2015-06-01

    Precipitation changes the physical and biological characteristics of an ecosystem. Using a precipitation-based conditional sampling technique and a 14 year dataset from a 25 m micrometeorological tower in a high-elevation subalpine forest, we examined how warm-season precipitation affected the above-canopy diel cycle of wind and turbulence, net radiation Rnet, ecosystem eddy covariance fluxes (sensible heat H, latent heat LE, and CO2 net ecosystem exchange NEE) and vertical profiles of scalars (air temperature Ta, specific humidity q, and CO2 dry mole fraction χc). This analysis allowed us to examine how precipitation modified these variables from hourly (i.e., the diel cycle) to multi-day time-scales (i.e., typical of a weather-system frontal passage). During mid-day we found: (i) even though precipitation caused mean changes on the order of 50-70% to Rnet, H, and LE, the surface energy balance (SEB) was relatively insensitive to precipitation with mid-day closure values ranging between 70-80%, and (ii) compared to a typical dry day, a day following a rainy day was characterized by increased ecosystem uptake of CO2 (NEE increased by ≈ 10%), enhanced evaporative cooling (mid-day LE increased by ≈ 30 W m-2), and a smaller amount of sensible heat transfer (mid-day H decreased by ≈ 70 W m-2). Based on the mean diel cycle, the evaporative contribution to total evapotranspiration was, on average, around 6% in dry conditions and 20% in wet conditions. Furthermore, increased LE lasted at least 18 h following a rain event. At night, precipitation (and accompanying clouds) reduced Rnet and increased LE. Any effect of precipitation on the nocturnal SEB closure and NEE was overshadowed by atmospheric phenomena such as horizontal advection and decoupling that create measurement difficulties. Above-canopy mean χc during wet conditions was found to be about 2-3 μmol mol-1 larger than χc on dry days. This difference was fairly constant over the full diel cycle

  16. Boreal mire carbon exchange: sensitivity to climate change and anthropogenic nitrogen and sulfur deposition

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Tobias

    2010-07-01

    Boreal peatlands are important long-term sinks of atmospheric carbon and in the same time the largest natural source of methane to the atmosphere. A changing climate as well as deposition of anthropogenically derived pollutants, such as nitrogen and sulfur, has the potential to affect the processes that control the carbon exchange in peatlands. Many of the biogeochemical responses to changed environmental conditions, such as changed plant community composition, are slow and therefore long-term studies are required. In this thesis I have investigated the long-term effects of nitrogen addition, sulfur addition and greenhouse enclosures on carbon exchange by using a field manipulation experiment in a boreal minerogenic, oligotrophic mire after 10-12 years of treatment. Treatment effects on CH{sub 4} emissions, gross primary production (GPP), ecosystem respiration (Reco) and net ecosystem exchange (NEE) were estimated from 1-2 seasons of chamber flux measurements. Treatment effects on potential CH{sub 4} production and oxidation were estimated in incubations of peat from different depth intervals. The effect of nitrogen deposition on carbon accumulation was evaluated in peat cores at different depth intervals. The long-term nitrogen additions have: shifted plant community composition from being dominated by Sphagnum to being dominated by sedges and dwarf shrubs; changed mire surface microtopography so that mean water table is closer to the surface in plots with high nitrogen; increased CH{sub 4} production and emission; increased Reco slightly but have not affected GPP or NEE; reduced the peat height increment, but increased both peat bulk density and carbon content, leading to an unchanged carbon accumulation. The long-term sulfur additions have not reduced CH{sub 4} emissions, only slightly reduced CH{sub 4} production and did not have any effect on the CO{sub 2} carbon exchange. The greenhouse treatment, manifested in increased air and soil temperatures, reduced

  17. Net ecosystem exchange of carbon dioxide and evapotranspiration response of a high elevation Rocky Mountain (Wyoming, USA) forest to a bark beetle epidemic

    Science.gov (United States)

    Frank, J. M.; Massman, W. J.; Ewers, B. E.

    2011-12-01

    Bark beetle epidemics have caused major disturbance in the forests of western North America where significant tree mortality alters the balance of ecosystem photosynthesis, carbon balance, and water exchange. In this study we investigate the change in the growing-season light-response of net ecosystem exchange of carbon dioxide (NEE) and evapotranspiration (ET) in a high elevation Rocky Mountain forest over the three years preceding and three years following a bark beetle outbreak. The GLEES AmeriFlux site (southeastern Wyoming, USA) is located in a high elevation subalpine forest dominated by Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) and recently experienced an epidemic of spruce beetle (Dendroctonus rufipennis). The peak beetle outbreak occurred in 2008, and has impacted 35% of the stems and 90% of the basal area of Engelmann spruce, which accounts for 30% of the trees and 70% of the basal area of the forest. Two semi-empirical light response curves for eddy-covariance carbon flux were compared, with a logistic sigmoid performing better because of residual bias than a rectangular hyperbola (Michaelis-Menten) at estimating the quantum yield of photosynthesis. In the first two years after the peak beetle outbreak the original quantum yield of 0.015 mol mol-1 was reduced by 25%. By the third year it was reduced by a half, which was composed of declines of 45% in the ecosystem's responses to diffuse radiation and 60% to direct radiation. The light-saturated rate of photosynthesis decreased by 10% in the first two years post outbreak, and fell by 40% in the third year. After the peak outbreak, the cumulative NEE over the growing season was reduced by over a half from a sink of 185 gC m-2 to 80 gC m-2, and by the third year it was reduced to near zero, or carbon neutral. The change in the ET response to light was similar in all years after the peak outbreak where the slope of the response curve was decreased by 25%. This led to a

  18. On the choice of the driving temperature for eddy-covariance carbon dioxide flux partitioning

    Science.gov (United States)

    Lasslop, G.; Migliavacca, M.; Bohrer, G.; Reichstein, M.; Bahn, M.; Ibrom, A.; Jacobs, C.; Kolari, P.; Papale, D.; Vesala, T.; Wohlfahrt, G.; Cescatti, A.

    2012-12-01

    Networks that merge and harmonise eddy-covariance measurements from many different parts of the world have become an important observational resource for ecosystem science. Empirical algorithms have been developed which combine direct observations of the net ecosystem exchange of carbon dioxide with simple empirical models to disentangle photosynthetic (GPP) and respiratory fluxes (Reco). The increasing use of these estimates for the analysis of climate sensitivities, model evaluation and calibration demands a thorough understanding of assumptions in the analysis process and the resulting uncertainties of the partitioned fluxes. The semi-empirical models used in flux partitioning algorithms require temperature observations as input, but as respiration takes place in many parts of an ecosystem, it is unclear which temperature input - air, surface, bole, or soil at a specific depth - should be used. This choice is a source of uncertainty and potential biases. In this study, we analysed the correlation between different temperature observations and nighttime NEE (which equals nighttime respiration) across FLUXNET sites to understand the potential of the different temperature observations as input for the flux partitioning model. We found that the differences in the correlation between different temperature data streams and nighttime NEE are small and depend on the selection of sites. We investigated the effects of the choice of the temperature data by running two flux partitioning algorithms with air and soil temperature. We found the time lag (phase shift) between air and soil temperatures explains the differences in the GPP and Reco estimates when using either air or soil temperatures for flux partitioning. The impact of the source of temperature data on other derived ecosystem parameters was estimated, and the strongest impact was found for the temperature sensitivity. Overall, this study suggests that the choice between soil or air temperature must be made on site

  19. On the choice of the driving temperature for eddy-covariance carbon dioxide flux partitioning

    Directory of Open Access Journals (Sweden)

    G. Lasslop

    2012-12-01

    Full Text Available Networks that merge and harmonise eddy-covariance measurements from many different parts of the world have become an important observational resource for ecosystem science. Empirical algorithms have been developed which combine direct observations of the net ecosystem exchange of carbon dioxide with simple empirical models to disentangle photosynthetic (GPP and respiratory fluxes (Reco. The increasing use of these estimates for the analysis of climate sensitivities, model evaluation and calibration demands a thorough understanding of assumptions in the analysis process and the resulting uncertainties of the partitioned fluxes. The semi-empirical models used in flux partitioning algorithms require temperature observations as input, but as respiration takes place in many parts of an ecosystem, it is unclear which temperature input – air, surface, bole, or soil at a specific depth – should be used. This choice is a source of uncertainty and potential biases. In this study, we analysed the correlation between different temperature observations and nighttime NEE (which equals nighttime respiration across FLUXNET sites to understand the potential of the different temperature observations as input for the flux partitioning model. We found that the differences in the correlation between different temperature data streams and nighttime NEE are small and depend on the selection of sites. We investigated the effects of the choice of the temperature data by running two flux partitioning algorithms with air and soil temperature. We found the time lag (phase shift between air and soil temperatures explains the differences in the GPP and Reco estimates when using either air or soil temperatures for flux partitioning. The impact of the source of temperature data on other derived ecosystem parameters was estimated, and the strongest impact was found for the temperature sensitivity. Overall, this study suggests that the

  20. Effects of recurring summer droughts on ecosystem photosynthesis and respiration in a mountain grassland

    Science.gov (United States)

    Schmitt, Michael; Ingrisch, Johannes; Sturm, Patrick; Ladreiter-Knauss, Thomas; Hasibeder, Roland; Bramboeck, Peter; Berger, Vanessa; Bahn, Michael

    2013-04-01

    Climatic changes in mountain regions play a key role in current and future grassland ecosystem processes. It is currently expected that droughts and heatwaves will become more frequent in a changing climate. All around the world mountain regions have been labelled as sensitive zones, where declining water availability and increasing temperature are expected to increase the vulnerability of these ecosystems. However, the effects of such extreme events on ecosystem carbon (C) fluxes and their coupling in temperate and so far non-water limited Alpine grasslands are not yet well understood. We studied effects of recurring summer drought on the C dynamics of a mountain meadow at 1820 m and an abandoned grassland at 2000 m in the Austrian Central Alps. The aim of the study was (1) to analyse the multiannual effect of drought on net ecosystem CO2 exchange (NEE) and its major component processes, i.e. gross primary productivity (GPP) and ecosystem respiration (Reco), and (2) to trace drought effects on the use of recent C in soil respiration. We tested the hypothesis that drought reduces NEE, GPP and Reco and the ratio of GPP / Reco and causes a reduction in the use of recent photoassimilates in belowground respiration. At each study site, exclusion of rainfall was achieved by establishing rain-out shelters for a period of two months (June, July), while control plots remained exposed to natural precipitation. To trace the fate of recent C from assimilation to respiration 13CO2 pulse-labelling was carried out at the meadow site, and the carbon isotope composition of soil respired CO2 was continuously monitored with an open dynamic-chamber system coupled with a quantum cascade laser. Our results showed that at both sites NEE, GPP and Reco showed a consistent reduction with reduction in soil water level. Drought reduced ecosystem respiration to a lesser extent than photosynthesis. We observed memory effects on all flux processes after 3 years of recurring drought on the

  1. What drives inter-annual variations in C flux and balance in a tropical rainforest of French Guiana?

    Science.gov (United States)

    Aguilos, Maricar; Herault, Bruno; Burban, Benoit; Wagner, Fabien; Bonal, Damien

    2017-04-01

    Amazon rainforests, a major contributor to the global carbon sink, is not on steady state and information about the long-term impact of climate change on carbon fluxes between this ecosystem and the atmosphere and the resulting balance is lacking. A thorough understanding of the forest responses to climate is indeed important to improve ecosystem process models and to reduce uncertainties in the contemporary carbon balance calculations for tropical forests. To address these issues, we examined the interannual variations in gross primary photosynthesis (GPP), ecosystem respiration (RE) and net ecosystem exchange (NEE) in a tropical rainforest in French Guiana and identified key climatic drivers influencing such changes across a 12-year long period (2004 - 2015). The study period was characterized by strong differences in climate conditions, particularly in the intensity of the long dry and the long wet seasons. Fluctuations in annual average GPP vary from 9.27 ± 1.68 g C m?2 d?1 to 11.13 ± 2.21 g C m?2 d?1. RE is more varied than GPP having a difference of 2.53 C m?2 d?1 between the minimum (8.28 ± 0.85 g C m?2 d?1) and maximum (10.80 ± 1.67 g C m?2 d?1). GPP was always higher than RE annually and the forest remained a carbon sink in an annual basis although NEE has huge interannual variability, from -0.18 ± 1.64 g C m?2 d?1 to -1.62 ± 1.65 g C m?2 d?1. Annually, the combination of global radiation (Rg), relative extractable water (REW) and soil temperature (Ts) explained 51% of the variations of GPP, 30% for RE, and 39% for NEE, but global radiation was always the best predictor variable. Seasonally, Rg was the major controlling factor for GPP (r2 = 0.58; P area index, tree growth or litterfall did not contribute much to explain these variations. This study highlights the importance of taking into consideration the main drivers of C fluxes and balance for each seasonal type when integrating them in land atmosphere models. Detailed mechanisms on the impact of

  2. Inferences from a community study about non-epileptic events Inferências de estudo populacional sobre eventos não epilépticos

    Directory of Open Access Journals (Sweden)

    Marleide da Mota Gomes

    2002-09-01

    Full Text Available OBJECTIVE: To demonstrate the epidemiological importance of the different types of non-epileptic events (NEE in a low-income urban community. METHOD: The patients suspected of having epilepsy, who were detected in the first phase (screening one of this prevalence study, were interviewed by a neurologist in a non-structured neurological interview. These NEE were classified as physiological and psychogenic, subdivided by various types. The psychogenic NEE were classified according to the DSM-IV criteria. RESULTS: We compared the cases suspected of having epilepsy (n=176 with those not suspected (n=806 and discovered that those cases suspected of having epilepsy had a greater median age (OBJETIVO: Demonstrar a importância epidemiológica dos diferentes tipos de eventos não epilépticos (ENE em uma comunidade urbana de baixa renda. METODO: Os casos suspeitos de terem epilepsia foram detectados na primeira fase de um estudo de prevalência de epilepsia, de triagem. Na segunda fase, eles foram entrevistados por um neurologista em entrevista não estruturada. Os casos de ENE foram classificados como fisiológicos ou psicogênicos e divididos em vários tipos. Esses últimos foram classificados segundo o DSM-IV. RESULTADOS: Entre os suspeitos de terem epilepsia (176, mais idosos do que os outros casos, <0.01, com predominância feminina, p<0.01 existem diferentes diagnósticos: eventos epilépticos sem causa aguda subjacente conhecida (20 ou com (convulsão febril e eclâmpsia. O diagnóstico mais prevalente é o de síncope (n=63; 35,8%, crises epilépticas, fenômeno tóxico paroxístico (incluso alcoolismo e trauma craniano, nos eventos fisiológicos, e transtornos dissociativos, ansiedade, entre os psicogênicos. O predomínio masculino está relacionado aos fenômenos tóxicos (p=0,02, e o feminino, aos fenômenos dissociativos (p=0,01. CONCLUSÃO: Dentre os ENE, sugere-se a importância populacional (epidemiológica da síncope, como j

  3. A regional high-resolution carbon flux inversion of North America for 2004

    Science.gov (United States)

    Schuh, A. E.; Denning, A. S.; Corbin, K. D.; Baker, I. T.; Uliasz, M.; Parazoo, N.; Andrews, A. E.; Worthy, D. E. J.

    2010-05-01

    Resolving the discrepancies between NEE estimates based upon (1) ground studies and (2) atmospheric inversion results, demands increasingly sophisticated techniques. In this paper we present a high-resolution inversion based upon a regional meteorology model (RAMS) and an underlying biosphere (SiB3) model, both running on an identical 40 km grid over most of North America. Current operational systems like CarbonTracker as well as many previous global inversions including the Transcom suite of inversions have utilized inversion regions formed by collapsing biome-similar grid cells into larger aggregated regions. An extreme example of this might be where corrections to NEE imposed on forested regions on the east coast of the United States might be the same as that imposed on forests on the west coast of the United States while, in reality, there likely exist subtle differences in the two areas, both natural and anthropogenic. Our current inversion framework utilizes a combination of previously employed inversion techniques while allowing carbon flux corrections to be biome independent. Temporally and spatially high-resolution results utilizing biome-independent corrections provide insight into carbon dynamics in North America. In particular, we analyze hourly CO2 mixing ratio data from a sparse network of eight towers in North America for 2004. A prior estimate of carbon fluxes due to Gross Primary Productivity (GPP) and Ecosystem Respiration (ER) is constructed from the SiB3 biosphere model on a 40 km grid. A combination of transport from the RAMS and the Parameterized Chemical Transport Model (PCTM) models is used to forge a connection between upwind biosphere fluxes and downwind observed CO2 mixing ratio data. A Kalman filter procedure is used to estimate weekly corrections to biosphere fluxes based upon observed CO2. RMSE-weighted annual NEE estimates, over an ensemble of potential inversion parameter sets, show a mean estimate 0.57 Pg/yr sink in North America

  4. Higher stability in forest-atmosphere exchange observed in a structurally diverse forest.

    Science.gov (United States)

    Tamrakar, R.; Rayment, M.; Moyano, F.; Herbst, M.; Mund, M.; Knohl, A.

    2016-12-01

    We tested the hypothesis that structurally diverse forests have greater stability on exchange processes with the atmosphere compared to forests with less diverse structure. In a case study, we assessed how net ecosystem exchange (NEE) and normalized maximum assimilation (Amax) varied over time in two forests in Germany based on 11 years of continuous eddy flux measurements. The two sites differ in structure as well as in species composition: one (Hainich) is an unmanaged, uneven-aged and heterogeneous mixed beech forest (65% beech), the other (Leinefelde) is a managed, even-aged and homogeneous pure beech stand. The two selected forests are of similar mean ages (about 130 years old) and exposed to similar air temperatures and vapour pressure deficits. Even though Hainich (the unmanaged forest) received higher rainfall (720 ± 134 mm vs 599±166 mm), the soil water availability showed no significant difference between both sites. Based on detailed biomass inventory, trees in Hainich are well distributed in all diameter at breast height (dbh) classes (10 to 90cm dbh) whereas in Leinefelde (the managed forest) trees are mostly confined to dbh classes of 40 to 55 cm. Our results showed a strong difference in inter-annual variability of NEE, which was lower in the unmanaged than in the managed site (coefficient of variation (CV) of 0.13 and 0.27, respectively). The lowest NEE was observed in both sites in 2004, a mast year and a year after the strong summer drought of 2003. The variation in the inter-annual normalized maximum assimilation (Amax) was lower in Hainich (standard deviation of 2.5 compared to 3.9 µmol m-2 s-1). Also, the seasonal course of Amax differed between the two forests which could explain why the mixed forest was more affected by the late summer drought of 2003, despite showing a more conservative carbon budget than the pure stand in the long term. The interannual anomaly in Amax was correlated with fruit production, the latter being larger in

  5. Indicadores de estresse e coping no contexto da educação inclusiva

    Directory of Open Access Journals (Sweden)

    Kelly Ambrosio Silveira

    2014-03-01

    Full Text Available A escola tem sido o principal meio de educação para alunos com necessidades educativas especiais (NEE, graças às políticas inclusivas. Mas as dificuldades vivenciadas na implementação de tais políticas podem contribuir para o desenvolvimento de estresse entre docentes. Tendo isso em vista, no presente artigo procurou-se identificar os estressores e os níveis de estresse docente e analisar variáveis sóciodemográficas, pessoais, do trabalho e dos alunos, de acordo com a presença de estresse. Dezenove professoras de classes de 1º, 2º e 3º ano do Ensino Fundamental de escolas públicas da cidade de Vitória/ES, regentes de classes com alunos com NEE, responderam ao Inventário de Sintomas de Stress para adultos de Lipp, a um questionário com variáveis de interesse e a seis escalas de estressores e de enfrentamento (coping, especialmente traduzidas e adaptadas para o presente estudo. A grande quantidade de alunos e seus problemas comportamentais foram os estressores mais frequentes. Especificamente com relação à educação inclusiva, destacaram-se a sobrecarga de serviço e a percepção de pouca preocupação governamental em fornecer subsídios para o trabalho. Todavia, cabe ressaltar que a inclusão de alunos com NEE foi um fator menos citado, podendo não ser a variável central para o estresse, uma vez que os docentes com estresse apontaram mais frequentemente a seguinte causa: a percepção de incompreensão pública frente ao trabalho docente. A partir dessa constatação, sugerem-se intervenções para a promoção do bem-estar entre os professores.

  6. Carbon budget over 12 years in a production crop under temperate climate

    Science.gov (United States)

    Buysse, Pauline; Bodson, Bernard; Debacq, Alain; De Ligne, Anne; Heinesch, Bernard; Manise, Tanguy; Moureaux, Christine; Aubinet, Marc

    2017-04-01

    Carbon dioxide (CO2) exchanges between crops and the atmosphere are influenced by both climatic and crop management drivers. The investigated crop, situated at the Lonzée Terrestrial Observatory (LTO, candidate ICOS site) in Belgium and managed for more than 70 years using conventional farming practices, was monitored over three complete sugar beet (or maize)/winter wheat/potato/winter wheat rotation cycles from 2004 to 2016. Continuous eddy-covariance measurements and regular biomass samplings were performed in order to obtain the daily and seasonal Net Ecosystem Exchange (NEE), Gross Primary Productivity, Total Ecosystem Respiration, Net Primary Productivity, and Net Biome Production (NBP). Meteorological data and crop management practices were also recorded. The main objectives were to analyze the CO2 flux responses to climatic drivers and to establish the C budget of the cropland. Crop type significantly influenced the measured CO2 fluxes. In addition to crop season duration, which had an obvious impact on cumulated NEE values for each crop type, the CO2 flux response to photosynthetic photon flux density, vapor pressure deficit and temperature differed between crop types, while no significant response to soil water content was observed in any of them. Besides, a significant positive relationship between crop residue amount and ecosystem respiration was observed. Over the 12 years, NEE was negative (-4.34 ± 0.21 kg C m-2) but NBP was positive (1.05 ± 0.30 kg C m-2), i.e. as soon as all lateral carbon fluxes - dominated by carbon exportation - are included in the budget, the site behaves as a carbon source. Intercrops were seen to play a major role in the carbon budget, being mostly due to the long time period it represented (59 % of the 12 year time period). An in-depth analysis of intercrop periods and, more specifically, growing cover crops (mustard in the case of our study), is developed in a companion poster (ref. abstract EGU2017-12216, session SSS9

  7. Encaminhamento de crianças com necessidades educacionais especiais em idade de estimulação precoce a escolas de Educação Infantil de um município de médio porte do Vale dos Sinos

    Directory of Open Access Journals (Sweden)

    Magali Quevedo Grave

    2012-03-01

    Full Text Available A educação inclusiva no Brasil vem sendo discutida principalmente no âmbito educacional. A inclusão de alunos com Necessidades Educacionais Especiais (NEE, em escola comum, é cada vez mais frequente, embora ainda muitos aspectos precisem ser repensados. Esta pesquisa teve por objetivo verificar como ocorre o encaminhamento dos sujeitos com NEE em idade de Estimulação Precoce de zero até 3 anos e 11 meses para as escolas de Educação Infantil de um município de médio porte do Vale dos Sinos. Compreendeu uma pesquisa transversal, de caráter quantitativo, de estatística descritiva, sendo a coleta de dados realizada a partir de um questionário estruturado, com questões abertas e fechadas, direcionado a todos os diretores das treze Escolas de Educação Infantil do município em questão. Das treze escolas, apenas uma não participou da pesquisa, visto que atualmente não possui matricula de crianças com NEE, totalizando uma amostra de 46 crianças em processos de inclusão educacional. Dessas, 12 crianças (26,8% foram encaminhadas pelo serviço de Estimulação Precoce mantido pela Associação de Pais e Amigos dos Excepcionais do referido município, 30 crianças (65,2% ingressaram na escola por iniciativa da própria família e 4 crianças (8%, por intervenção do Conselho Tutelar. Neste sentido, acredita-se que cabe aos profissionais da Estimulação Precoce divulgar e argumentar a importância e, principalmente, os benefícios da Estimulação Precoce para o desenvolvimento global dos sujeitos e sua constituição, além da sua contribuição para o processo de educação inclusiva.Palavras-chave: Estimulação Precoce. Inclusão EducacionalJ. Escolas de Educação Infantil.

  8. Carbon cycling of European croplands: A framework for the assimilation of optical and microwave Earth observation data

    Science.gov (United States)

    Revill, Andrew; Sus, Oliver; Williams, Mathew

    2013-04-01

    Croplands are traditionally managed to maximise the production of food, feed, fibre and bioenergy. Advancements in agricultural technologies, together with land-use change, have approximately doubled World grain harvests over the past 50 years. Cropland ecosystems also play a significant role in the global carbon (C) cycle and, through changes to C storage in response to management activities, they can provide opportunities for climate change mitigation. However, quantifying and understanding the cropland C cycle is complex, due to variable environmental drivers, varied management practices and often highly heterogeneous landscapes. Efforts to upscale processes using simulation models must resolve these challenges. Here we show how data assimilation (DA) approaches can link C cycle modelling to Earth observation (EO) and reduce uncertainty in upscaling. We evaluate a framework for the assimilation of leaf area index (LAI) time series, empirically derived from EO optical and radar sensors, for state-updating a model of crop development and C fluxes. Sensors are selected with fine spatial resolutions (20-50 m) to resolve variability across field sizes typically used in European agriculture. Sequential DA is used to improve the canopy development simulation, which is validated by comparing time-series LAI and net ecosystem exchange (NEE) predictions to independent ground measurements and eddy covariance observations at multiple European cereal crop sites. Significant empirical relationships were established between the LAI ground measurements and the optical reflectance and radar backscatter, which allowed for single LAI calibrations being valid for all the cropland sites for each sensor. The DA of all EO LAI estimates results indicated clear adjustments in LAI and an enhanced representation of daily CO2 exchanges, particularly around the time of peak C uptake. Compared to the simulation without DA, the assimilation of all EO LAI estimates improved the predicted at

  9. Multiple independent constraints help resolve net ecosystem carbon exchange under nutrient limitation

    Science.gov (United States)

    Thornton, P. E.; Metcalfe, D.; Oren, R.; Ricciuto, D. M.

    2014-12-01

    The magnitude, spatial distribution, and variability of land net ecosystem exchange of carbon (NEE) are important determinants of the trajectory of atmospheric carbon dioxide concentration. Independent observational constraints provide important clues regarding NEE and its component fluxes, with information available at multiple spatial scales: from cells, to leaves, to entire organisms and collections of organisms, to complex landscapes and up to continental and global scales. Experimental manipulations, ecosystem observations, and process modeling all suggest that the components of NEE (photosynthetic gains, and respiration and other losses) are controlled in part by the availability of mineral nutrients, and that nutrient limitation is a common condition in many biomes. Experimental and observational constraints at different spatial scales provide a complex and sometimes puzzling picture of the nature and degree of influence of nutrient availability on carbon cycle processes. Photosynthetic rates assessed at the cellular and leaf scales are often higher than the observed accumulation of carbon in plant and soil pools would suggest. We infer that a down-regulation process intervenes between carbon uptake and plant growth under conditions of nutrient limitation, and several down-regulation mechanisms have been hypothesized and tested. A recent evaluation of two alternative hypotheses for down-regulation in the light of whole-plant level flux estimates indicates that some plants take up and store extra carbon, releasing it to the environment again on short time scales. The mechanism of release, either as additional autotrophic respiration or as exudation belowground is unclear, but has important consequences for long-term ecosystem state and response to climate change signals. Global-scale constraints from atmospheric concentration and isotopic composition data help to resolve this question, ultimately focusing attention on land use fluxes as the most uncertain

  10. Patterns and controls of inter-annual variability in the terrestrial carbon budget

    Science.gov (United States)

    Marcolla, Barbara; Rödenbeck, Christian; Cescatti, Alessandro

    2017-08-01

    The terrestrial carbon fluxes show the largest variability among the components of the global carbon cycle and drive most of the temporal variations in the growth rate of atmospheric CO2. Understanding the environmental controls and trends of the terrestrial carbon budget is therefore essential to predict the future trajectories of the CO2 airborne fraction and atmospheric concentrations. In the present work, patterns and controls of the inter-annual variability (IAV) of carbon net ecosystem exchange (NEE) have been analysed using three different data streams: ecosystem-level observations from the FLUXNET database (La Thuile and 2015 releases), the MPI-MTE (model tree ensemble) bottom-up product resulting from the global upscaling of site-level fluxes, and the Jena CarboScope Inversion, a top-down estimate of surface fluxes obtained from observed CO2 concentrations and an atmospheric transport model. Consistencies and discrepancies in the temporal and spatial patterns and in the climatic and physiological controls of IAV were investigated between the three data sources. Results show that the global average of IAV at FLUXNET sites, quantified as the standard deviation of annual NEE, peaks in arid ecosystems and amounts to ˜ 120 gC m-2 y-1, almost 6 times more than the values calculated from the two global products (15 and 20 gC m-2 y-1 for MPI-MTE and the Jena Inversion, respectively). Most of the temporal variability observed in the last three decades of the MPI-MTE and Jena Inversion products is due to yearly anomalies, whereas the temporal trends explain only about 15 and 20 % of the variability, respectively. Both at the site level and on a global scale, the IAV of NEE is driven by the gross primary productivity and in particular by the cumulative carbon flux during the months when land acts as a sink. Altogether these results offer a broad view on the magnitude, spatial patterns and environmental drivers of IAV from a variety of data sources that can be

  11. Sensitivity of Temperate Desert Steppe Carbon Exchange to Seasonal Droughts and Precipitation Variations in Inner Mongolia, China

    Science.gov (United States)

    Yang, Fulin; Zhou, Guangsheng

    2013-01-01

    Arid grassland ecosystems have significant interannual variation in carbon exchange; however, it is unclear how environmental factors influence carbon exchange in different hydrological years. In this study, the eddy covariance technique was used to investigate the seasonal and interannual variability of CO2 flux over a temperate desert steppe in Inner Mongolia, China from 2008 to 2010. The amounts and times of precipitation varied significantly throughout the study period. The precipitation in 2009 (186.4 mm) was close to the long-term average (183.9±47.6 mm), while the precipitation in 2008 (136.3 mm) and 2010 (141.3 mm) was approximately a quarter below the long-term average. The temperate desert steppe showed carbon neutrality for atmospheric CO2 throughout the study period, with a net ecosystem carbon dioxide exchange (NEE) of −7.2, −22.9, and 26.0 g C m−2 yr−1 in 2008, 2009, and 2010, not significantly different from zero. The ecosystem gained more carbon in 2009 compared to other two relatively dry years, while there was significant difference in carbon uptake between 2008 and 2010, although both years recorded similar annual precipitation. The results suggest that summer precipitation is a key factor determining annual NEE. The apparent quantum yield and saturation value of NEE (NEEsat) and the temperature sensitivity coefficient of ecosystem respiration (Reco) exhibited significant variations. The values of NEEsat were −2.6, −2.9, and −1.4 µmol CO2 m−2 s−1 in 2008, 2009, and 2010, respectively. Drought suppressed both the gross primary production (GPP) and Reco, and the drought sensitivity of GPP was greater than that of Reco. The soil water content sensitivity of GPP was high during the dry year of 2008 with limited soil moisture availability. Our results suggest the carbon balance of this temperate desert steppe was not only sensitive to total annual precipitation, but also to its seasonal distribution. PMID:23393576

  12. Relating Leaf Nitrogen, Leaf Photosynthesis and Canopy CO2 Exchange in a Temperate Winter Barley Field

    Science.gov (United States)

    Jensen, R.; Boegh, E.; Herbst, M.; Friborg, T.

    2012-12-01

    Net exchange of CO2 between the atmosphere and the soil-vegetation interface (NEE) is controlled by a wide range of biochemical and biophysical processes where leaf photosynthesis is often the most important. In mechanistically and physically based photosynthesis models (e.g. Farquhar et al. 1980) leaf nutrient status is a limiting factor for the photosynthetic capacity since it is implicitly incorporated through the parameters of maximum rate of carboxylation of CO2 (Vcmax) and the maximum rate of electron transport (Jmax). These are closely related to leaf nitrogen concentration (Na) and leaf chlorophyll content (Cab) and often show a characteristic seasonal dynamic. When simulating CO2 exchange, model outputs are sensitive to leaf photosynthetic capacity, which is labour consuming to verify through field measurements. A less time consuming method is to measure leaf "greenness" (SPAD), which is closely related to chlorophyll content and thus photosynthetic capacity. In the present study field measurements of leaf photosynthesis (LI-6400, LICOR Inc.), leaf reflectance (SPAD-502, Minolta), and LAI (LAI-2000, LICOR Inc.) were conducted on agricultural fields in Western Denmark during one growing season. The leaf photosynthesis measurements provided the basis for estimating photosynthetic capacity. SPAD measurements and LAI was measured with a higher spatial and temporal resolution. SPAD readings were calibrated against Cab and Na analyzed on leaf material in the laboratory and later correlated to photosynthetic capacity. These data were used to parameterize a coupled photosynthesis and stomatal model that was run for the growing season 2012 to estimate NEE. As a part of the hydrological observatory HOBE (hobe.dk), fluxes of greenhouse gasses are continuously measured by eddy covariance systems at three field sites in the Skjern River Catchment, Western Denmark, providing the basis for estimating the exchange of energy, water vapour, and CO2 on canopy scale. One of

  13. A novel method for measuring trace gas fluxes from tall vegetation

    Science.gov (United States)

    Keane, James; Phil, Ineson

    2014-05-01

    The nature of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) as greenhouse gases (GHGs) means that accurate measurement of their net ecosystem exchange (NEE) is extremely important to our ability to manage climate change. Manual static chambers are commonly used to measure soil fluxes of these trace gases, with landscape values extrapolated from point measurements of typically less than 1m2, at a weekly or monthly frequency. Moreover, due to the reliance upon manual sampling, data are typically biased towards day-time measurements, and use of opaque chambers halts photosynthesis. Automation of chambers, such as the Licor Li-8100 (Lincoln, NE) system, allows for measurement of soil respiration at a near-constant frequency, but does not solve the problem of measuring CH4 and N2O, neither does it allow measurements to be taken from over tall (more than 20 cm) vegetation. Eddy covariance (EC) techniques allow for high frequency measurements of CO2 and CH4 to be made at the landscape scale, and are increasingly available for N2O. However, the inability of EC to resolve to the plot scale hinders its use for manipulative experiments, and replication is rare. Additionally, stratification of the boundary layer creates difficulty in measuring night-time fluxes and it is common to discard large parts of data sets due to unsuitable wind direction or other meteorological conditions. Here we present a new technique for measuring trace gas fluxes from over tall vegetation. The system is capable of simultaneously delivering NEE of CO2, CH4 and N2O, automatically measuring at high temporal resolution (circa hourly) from replicated plots. We show the effect of green compost addition on trace gas fluxes from Miscanthus x giganteus, an important crop for bioenergy production. The ability to quantify NEE of GHGs from such crops forms an essential part of the lifecycle analysis of energy produced from biomass, which may play an important role in future mitigation of climate

  14. Differences in Net Ecosystem Exchange for an intensely managed watershed using a lumped, regional model and a mechanistic, hillslope-scale model

    Science.gov (United States)

    Wilson, C. G.; Wacha, K.; Papanicolaou, T.; Stanier, C. O.; Jamroensan, A.

    2014-12-01

    In this study, Net Ecosystem Exchange (NEE), and its components Gross Ecosystem Exchange (GEE) and Ecosystem Respiration (RESP), were compared from a lumped, regional model and a mechanistic, hillslope-scale model to determine if the effects of land management on the carbon cycle are captured by larger-scale biosphere models that determine CO2 sources and sinks. WRF-VPRM (Weather Research & Forecasting - Vegetation Photosynthesis & Respiration Model) is a regional-scale model that uses simulated downward shortwave radiation and surface temperatures, along with satellite-derived land cover indices and eddy flux tower-derived parameters to estimate biosphere CO2 fluxes with empirical equations. The DAYCENT biogeochemical model coupled with the Watershed Erosion Prediction Project model (WEPP), which simulates changes in soil carbon stocks due to different land management and the resulting enhanced erosion, can also quantify biosphere CO2 fluxes. Both models (i.e., WRF-VPRM and WEPP-DAYCENT) were used to quantify GEE, RESP, and NEE for the summer of 2008 in the IML-CZO Clear Creek watershed of the U.S. Midwest to examine the role of land management heterogeneity in CO2 exchanges between the biosphere and atmosphere. Comparing average daily GEE rates from WRF-VPRM (-11.0 ± 5.2 g C/m2/d) with WEPP-DAYCENT average values weighted per land use area in the watershed (-10.2 ± 1.5 g C/m2/d) showed no significant differences (t-test; p=0.08). In contrast, daily RESP values were different between the two models. Daily respiration rates were relatively constant for WRF-VPRM (6.0 ± 0.8 g C/m2/d), while WEPP-DAYCENT values for each management practice were significantly greater (7.2 ± 1.8 g C/m2/d; t-test, pmanagement and net erosion/deposition on total SOC stocks and tillage impacts on respiration by increasing decomposition from the breaking of soil aggregates and enhanced mineralization. In WRF-VPRM, respiration is calculated with a regression equation based on air

  15. Interactive effects of nocturnal transpiration and climate change on the root hydraulic redistribution and carbon and water budgets of southern United States pine plantations.

    Science.gov (United States)

    Domec, Jean-Christophe; Ogée, Jérôme; Noormets, Asko; Jouangy, Julien; Gavazzi, Michael; Treasure, Emrys; Sun, Ge; McNulty, Steve G; King, John S

    2012-06-01

    Deep root water uptake and hydraulic redistribution (HR) have been shown to play a major role in forest ecosystems during drought, but little is known about the impact of climate change, fertilization and soil characteristics on HR and its consequences on water and carbon fluxes. Using data from three mid-rotation loblolly pine plantations, and simulations with the process-based model MuSICA, this study indicated that HR can mitigate the effects of soil drying and had important implications for carbon uptake potential and net ecosystem exchange (NEE), especially when N fertilization is considered. At the coastal site (C), characterized by deep organic soil, HR increased dry season tree transpiration (T) by up to 40%, and such an increase affected NEE through major changes in gross primary productivity (GPP). Deep-rooted trees did not necessarily translate into a large volume of HR unless soil texture allowed large water potential gradients to occur, as was the case at the sandy site (S). At the Piedmont site (P) characterized by a shallow clay-loam soil, HR was low but not negligible, representing up to 10% of T. In the absence of HR, it was predicted that at the C, S and P sites, annual GPP would have been diminished by 19, 7 and 9%, respectively. Under future climate conditions HR was predicted to be reduced by up to 25% at the C site, reducing the resilience of trees to precipitation deficits. The effect of HR on T and GPP was predicted to diminish under future conditions by 12 and 6% at the C and P sites, respectively. Under future conditions, T was predicted to stay the same at the P site, but to be marginally reduced at the C site and slightly increased at the S site. Future conditions and N fertilization would decrease T by 25% at the C site, by 15% at the P site and by 8% at the S site. At the C and S sites, GPP was estimated to increase by 18% and by >70% under future conditions, respectively, with little effect of N fertilization. At the P site, future

  16. Bioindicative Parameters of Stand Growth Stability in the Disturbed Landscapes of Krasnoyarsk and Achinsk Forest-Steppe Regions

    Directory of Open Access Journals (Sweden)

    L. N. Skripalshikova

    2014-04-01

    Full Text Available Estimation of growth stability of Betula pendula and Populus balsamifera stands in anthropogenic landscapes in Krasnoyarsk and Achinsk forest-steppe regions was carried out by the values of fluctuating asymmetry (FA. Well-formed dependence of asymmetry increasing in leaves and needles of studied species in natural stands based on the value of technogenic loads and the distance from pollution sources was established. Indices of nee-dle asymmetry at organismic and tissue levels were obtained for Pinus sylvestris from the zone of intensive technogenic loadings in Krasnoyarsk forest-steppe region for the first time. Rating scale of growth stability deviations was designed for pine stands in disturbed regions of Krasnoyarsk forest-steppe.

  17. Carbon balance of the typical grain crop rotation in Moscow region assessed by eddy covariance method

    Science.gov (United States)

    Meshalkina, Joulia; Yaroslavtsev, Alexis; Vassenev, Ivan

    2017-04-01

    Croplands could have equal or even greater net ecosystem production than several natural ecosystems (Hollinger et al., 2004), so agriculture plays a substantial role in mitigation strategies for the reduction of carbon dioxide emissions. In Central Russia, where agricultural soils carbon loses are 9 time higher than natural (forest's) soils ones (Stolbovoi, 2002), the reduction of carbon dioxide emissions in agroecosystems must be the central focus of the scientific efforts. Although the balance of the CO2 mostly attributed to management practices, limited information exists regarding the crop rotation overall as potential of C sequestration. In this study, we present data on carbon balance of the typical grain crop rotation in Moscow region followed for 4 years by measuring CO2 fluxes by paired eddy covariance stations (EC). The study was conducted at the Precision Farming Experimental Fields of the Russian Timiryazev State Agricultural University, Moscow, Russia. The experimental site has a temperate and continental climate and situated in south taiga zone with Arable Sod-Podzoluvisols (Albeluvisols Umbric). Two fields of the four-course rotation were studied in 2013-2016. Crop rotation included winter wheat (Triticum sativum L.), barley (Hordeum vulgare L.), potato crop (Solanum tuberosum L.) and cereal-legume mixture (Vicia sativa L. and Avena sativa L.). Crops sowing occurred during the period from mid-April to mid-May depending on weather conditions. Winter wheat was sown in the very beginning of September and the next year it occurred from under the snow in the phase of tillering. White mustard (Sinapis alba) was sown for green manure after harvesting winter wheat in mid of July. Barley was harvested in mid of August, potato crop was harvested in September. Cereal-legume mixture on herbage was collected depending on the weather from early July to mid-August. Carbon uptake (NEE negative values) was registered only for the fields with winter wheat and white

  18. ENHANCING SPIRITUALISM IN VIRTUAL WORLD

    Directory of Open Access Journals (Sweden)

    Kiran Lata DANGWAL

    2012-04-01

    Full Text Available Spiritualism is one word which puts man on the highest plinth of life. Spirituality is the way we find meaning, hope, comfort and inner peace in life. Spirituality in the virtual World is generally known as Virtual Spirituality. A goldmine of wisdom from all kinds of religious and spiritual philosophies, traditions and practices can be found in virtual World now. Technology and Spirituality together forms the material to which man can incline on to and work for the development of a globe in which war will be considered a taboo and violence a rejected dogma. Therefore there is an urgent nee to made the world a safe place to live in and the spiritual reconstruction can help us in achieving this.Spiritualism, Virtual World, Online Technology.

  19. Epidemiology and molecular diversity of rabies viruses in Bulgaria.

    Science.gov (United States)

    Robardet, E; Ilieva, D; Iliev, E; Gagnev, E; Picard-Meyer, E; Cliquet, F

    2014-04-01

    A health emergency situation occurred in Bulgaria in 2007 when positive rabies cases were notified in Sofia district in the central-western part of the country, suggesting a southward spread of the disease for the first time in the last 10 years. Phylogenetic analysis on 49 isolates sampled between 2009 and 2011 showed, for the first time, evidence of the existence of NEE and D clustered lineages in Bulgaria. Their geographical distribution clearly reveals the permeability of natural barriers, as already suggested by the disease spread that occurred across the Balkan mountain range in 2007. The monitoring and passive surveillance programmes conducted since the first 2009 oral vaccination campaign, the spatio-temporal evolution of the disease in the country since 2007, and the need for further investigation of the role of jackals in virus dispersion are discussed.

  20. Molecular epidemiology of rabies virus in Poland.

    Science.gov (United States)

    Orłowska, Anna; Żmudziński, Jan Franciszek

    2014-08-01

    The paper describes a phylogenetic study of 58 Polish isolates of rabies virus collected between 1992 and 2010. Sequences of the nucleoprotein (N) and glycoprotein (G) genes approximately 600 bp long were compared with reference sequences (GenBank) of European rabies viruses from neighbouring countries. The study confirmed a very high level of homology (94.4-100 %) of the Polish rabies virus strains irrespective of the date of isolation. Two variants of rabies virus: NEE (Northeastern Europe variant) and CE (Central Europe variant), depending on the geographical place of isolation, were circulating in Poland from 1992 to 2010. The Polish rabies virus isolates showed high similarity to European RABV strains, especially those collected in Ukraine and Romania. They were clearly different from vaccine strains SAD B19 and SAD Bern, which have been used for oral vaccination of foxes against rabies in Poland since 1993.

  1. An electrophysiological signature for proactive interference resolution in working memory.

    Science.gov (United States)

    Du, Yingchun; Xiao, Zhuangwei; Song, Yan; Fan, Silu; Wu, Renhua; Zhang, John X

    2008-08-01

    We used event-related potentials (ERPs) to study the temporal dynamics of proactive interference in working memory. Participants performed a Sternberg item-recognition task to determine whether a probe was in a target memory set. Familiar negative probes were found to be more difficult to reject than less familiar ones. A fronto-central N2 component peaking around 300 ms post-probe-onset differentiated among target probes, familiar and less familiar non-target probes. The study identifies N2 as the ERP signature for proactive interference resolution. It also indicates that the resolution process occurs in the same time window as target/non-target discrimination and provides the first piece of electrophysiological evidence supporting a recent interference resolution model based on localization data [Jonides, J., Nee, D.E., 2006. Brain mechanisms of proactive interference in working memory. Neuroscience 139, 181-193].

  2. Free-Space Nonlinear Beam Combining Towards Filamentation

    CERN Document Server

    Rostami, Shermineh; Kepler, Daniel; Baudelet, Matthieu; Litchinitser, Natalia M; Richardson, Martin

    2016-01-01

    Multi-filamentation opens new degrees of freedom for manipulating electromagnetic waves in air. However, without control, multiple filament interactions, including attraction, repulsion or fusion often result in formation of complex disordered filament distributions. Moreover, high power beams conventionally used in multi-filament formation experiments often cause significant surface damage. The growing number of applications for laser filaments requires fine control of their formation and propagation. We demonstrate, experimentally and theoretically, that the attraction and fusion of ultrashort beams with initial powers below the critical value enable the eventual formation of a filament downstream. Filament formation is delayed to a predetermined distance in space, avoiding optical damage to external beam optics while still enabling robust filaments with controllable properties as if formed from a single high power beam. This paradigm introduces new opportunities for filament engineering eliminating the nee...

  3. Scratch y Necesidades Educativas Especiales: Programación para todos

    Directory of Open Access Journals (Sweden)

    Carmen López-Escribano

    2012-01-01

    Full Text Available Este trabajo tiene como objetivo principal animar a los maestros y educadores a utilizar el lenguaje de programación Scratch en sus clases con alumnos con necesidades educativas especiales. Scratch es un lenguaje visual de fácil uso y de libre distribución que favorece un método de aprendizaje activo y constructivo. Para que los maestros se animen a utilizar este programa exponemos experiencias de uso del programa con niños con diferentes necesidades y estilos de aprendizaje y ofrecemos una lista de recursos para hacer el programa accesible. También proponemos diferentes usos del programa, como es crear proyectos que sirvan para la rehabilitación de dificultades de aprendizaje. Las experiencias de utilizar Scratch con estudiantes con NEE, realizadas hasta la fecha, han sido siempre positivas y motivadoras.

  4. Leaf anatomy of the South African Danthonieae (Poaceae. XIII. Pentameris macrocalycina and P. obtusifolia

    Directory of Open Access Journals (Sweden)

    R. P. Ellis

    1984-12-01

    Full Text Available The leaf blade anatomy of Peniameris macrocalycina (Steud. Schweick. and P. obtusifolia (Hochst, Schweick. is described and illustrated. The leaf anatomy of these two species shows many similarities suggesting a close relationship between them. A slight problem appears to exist with the circumscription of P. obtusifolia and a minor taxonomic adjustment may result in a classification which agrees totally with that based on leaf anatomy. This would result in details of the leaf outline being diagnostic for these two taxa. The nomenclature of P. obtusifolia is also very confusing and clarification is needed by reference to the relevant type specimens. P. macrocalycina and P. obtusifolia together with  P. longiglumis (Nees Stapf, appear to form a distinct genus and do not bear close anatomical resemblances to either P. thuarri Beauv. or P. dregeana Stapf.

  5. Leaf anatomy of the South African Danthonieae (Poaceae. III. Merxmuellera stricta

    Directory of Open Access Journals (Sweden)

    R. P. Ellis

    1980-12-01

    Full Text Available The anatomical structure, of the leaf blade as seen in transverse section, and of the abaxial epidermis, of Merxmuellera stricta (Schrad. Conert is described and illustrated. In this variable species four distinct anatomical “forms” are recognized viz. the typical  M. stricta form, the Cathedral Peak form, the Drakensberg form and the alpine form. The alpine and Cathedral Peak forms have recently been described as M. guillarmodiae Conert (1975. The degree of anatomical differentiation of these “forms” resembles the situation described in M. disticha (Nees Conert (Ellis, 1980. Populations of both M. stricta and M. disticha from the Drakensberg mountains display extensive anatomical diversification which appears to be correlated with environmental factors. In addition, morphological differences are exhibited as well and the anatomical “forms” of M. stricta probably warrant taxonomic recognition.

  6. Epidemiologic and economic evaluation of risk-based meat inspection for bovine cysticercosis in Danish cattle

    DEFF Research Database (Denmark)

    Calvo Artavia, Francisco Fernando; Nielsen, Liza Rosenbaum; Alban, L.

    2013-01-01

    simulation model for analysis of tentative risk-based meat inspection systems for BC in Danish cattle with regard to system sensitivity (SSSe), specificity and potential monetary benefits compared to the current system, which has an estimated SSSe of 15%. The relevant risk factors used to construct three...... system, and highest effectiveness ratios, but they had a lower net economic effect (NEE) than the scenario using risky water sources. Using gender to differentiate high and low-risk groups was judged preferable over grazing due to feasibility, because the information is readily available at the slaughter...... in the current meat inspection and under the investigated risk-based meat inspection systems. Therefore, improving the sensitivity of the methods used for inspection of high-risk cattle would be beneficial....

  7. Soil Moisture Active Passive Mission L4_C Data Product Assessment (Version 2 Validated Release)

    Science.gov (United States)

    Kimball, John S.; Jones, Lucas A.; Glassy, Joseph; Stavros, E. Natasha; Madani, Nima; Reichle, Rolf H.; Jackson, Thomas; Colliander, Andreas

    2016-01-01

    The SMAP satellite was successfully launched January 31st 2015, and began acquiring Earth observation data following in-orbit sensor calibration. Global data products derived from the SMAP L-band microwave measurements include Level 1 calibrated and geolocated radiometric brightness temperatures, Level 23 surface soil moisture and freezethaw geophysical retrievals mapped to a fixed Earth grid, and model enhanced Level 4 data products for surface to root zone soil moisture and terrestrial carbon (CO2) fluxes. The post-launch SMAP mission CalVal Phase had two primary objectives for each science product team: 1) calibrate, verify, and improve the performance of the science algorithms, and 2) validate accuracies of the science data products as specified in the L1 science requirements. This report provides analysis and assessment of the SMAP Level 4 Carbon (L4_C) product pertaining to the validated release. The L4_C validated product release effectively replaces an earlier L4_C beta-product release (Kimball et al. 2015). The validated release described in this report incorporates a longer data record and benefits from algorithm and CalVal refinements acquired during the SMAP post-launch CalVal intensive period. The SMAP L4_C algorithms utilize a terrestrial carbon flux model informed by SMAP soil moisture inputs along with optical remote sensing (e.g. MODIS) vegetation indices and other ancillary biophysical data to estimate global daily net ecosystem CO2 exchange (NEE) and component carbon fluxes for vegetation gross primary production (GPP) and ecosystem respiration (Reco). Other L4_C product elements include surface (10 cm depth) soil organic carbon (SOC) stocks and associated environmental constraints to these processes, including soil moisture and landscape freeze/thaw (FT) controls on GPP and respiration (Kimball et al. 2012). The L4_C product encapsulates SMAP carbon cycle science objectives by: 1) providing a direct link between terrestrial carbon fluxes and

  8. Inhibitory Effect of Helicteres gardneriana Ethanol Extract on Acute Inflammation

    Directory of Open Access Journals (Sweden)

    Juliana Oliveira de Melo

    2012-01-01

    Full Text Available The anti-inflammatory effect of an ethanol extract of Helicteres gardneriana (Nees Castiglioni was assayed in experimental models of pleurisy and microcirculation in situ. Treatment of animals with 500 mg/kg body weight reduced the exudate volume (35% reduction induced by intrapleural injection of carrageenan and the migration of polymorphonuclear cells into the inflamed pleural cavity of rats (40%. Additionally, rolling and adhesion of leukocytes and the number of leukocytes that migrated toward the perivascular space in response to the carrageenan injection were decreased by the extract (500 mg/kg. These data demonstrate the anti-inflammatory effect of the ethanol extract of Helicteres gardneriana and imply that inhibition of leukocyte-endothelial interactions is important in the extract's mechanism of action.

  9. Gap filling strategies for long term energy flux data sets

    DEFF Research Database (Denmark)

    Falge, E.; Baldocchi, D.; Olson, R.

    2001-01-01

    At present a network of over 100 field sites are measuring carbon dioxide, water vapor and sensible heat fluxes between the biosphere and atmosphere, on a nearly continuous basis. Gaps in the long term measurements of evaporation and sensible heat flux must be filled before these data can be used...... for hydrological and meteorological applications. We adapted methods of gap filling for NEE (net ecosystem exchange of carbon) to energy fluxes and applied them to data sets available from the EUROFLUX and AmeriFlux eddy covariance databases. The average data coverage for the sites selected was 69% and 75......% for latent heat (lambdaE) and sensible heat (H). The methods were based on mean diurnal variations (half-hourly binned means of fluxes based on previous and subsequent days, MDV) and look-up tables for fluxes during assorted meteorological conditions (LookUp), and the impact of different gap filling methods...

  10. Studies in the southern African species of Justicia and Siphonoglossa (Acanthaceae: seeds

    Directory of Open Access Journals (Sweden)

    K. L. Immelman

    1990-12-01

    Full Text Available The seeds of all species of Justicia (except J. thymifolia (Nees C.B. Cl. and Siphonoglossa in the southern African region (as defined by the Flora of southern Africa were examined with the Scanning Electron Microscope. A wide range of different seed surfaces were seen, many of which could be correlated with other characters to further reinforce grouping of species into sections. However, some species that on other characters, would be placed together, had widely differing seed testas. Gross surface morphology varied from smooth to colliculate, irregularly rugose, reticulate with the ridges variously arranged, wheel-shaped (radiate or ammonite-like, with a central ridge or with multicellular barbed scales. The seeds were without hairs, unlike some American species sometimes considered to belong in Justicia (Graham 1989. Micromorphology also provided useful characters, with seeds being reticulate, papillate, minutely or deeply rugose or with one to many crystals visible. Critical-point drying was sometimes helpful in viewing microstructure.

  11. Isolation and identification of bioactive compounds in Andrographis paniculata (Chuanxinlian

    Directory of Open Access Journals (Sweden)

    Lin Bi-Fong

    2010-05-01

    Full Text Available Abstract Andrographis paniculata (Burm. f. Nees (Acanthaceae is a medicinal plant used in many countries. Its major constituents are diterpenoids, flavonoids and polyphenols. Among the single compounds extracted from A. paniculata, andrographolide is the major one in terms of bioactive properties and abundance. Among the andrographolide analogues, 14-deoxy-11,12-didehydroandrographolide is immunostimulatory, anti-infective and anti-atherosclerotic; neoandrographolide is anti-inflammatory, anti-infective and anti-hepatotoxic; 14-deoxyandrographolide is immunomodulatory and anti-atherosclerotic. Among the less abundant compounds from A. paniculata, andrograpanin is both anti-inflammatory and anti-infective; 14-deoxy-14,15-dehydroandrographolide is anti-inflammatory; isoandrographolide, 3,19-isopropylideneandrographolide and 14-acetylandrographolide are tumor suppressive; arabinogalactan proteins are anti-hepatotoxic. The four flavonoids from A. paniculata, namely 7-O-methylwogonin, apigenin, onysilin and 3,4-dicaffeoylquinic acid are anti-atherosclerotic.

  12. Central Russia agroecosystem monitoring with CO2 fluxes analysis by eddy covariance method

    Directory of Open Access Journals (Sweden)

    Joulia Meshalkina

    2015-07-01

    Full Text Available The eddy covariance (EC technique as a powerful statistics-based method of measurement and calculation the vertical turbulent fluxes of greenhouses gases within atmospheric boundary layers provides the continuous, long-term flux information integrated at the ecosystem scale. An attractive way to compare the agricultural practices influences on GHG fluxes is to divide a crop area into subplots managed in different ways. The research has been carried out in the Precision Farming Experimental Field of the Russian Timiryazev State Agricultural University (RTSAU, Moscow in 2013 under the support of RF Government grant # 11.G34.31.0079, EU grant # 603542 LUС4С (7FP and RF Ministry of education and science grant # 14-120-14-4266-ScSh. Arable Umbric Albeluvisols have around 1% of SOC, 5.4 pH (KCl and NPK medium-enhanced contents in sandy loam topsoil. The CO2 flux seasonal monitoring has been done by two eddy covariance stations located at the distance of 108 m. The LI-COR instrumental equipment was the same for the both stations. The stations differ only by current crop version: barley or vetch and oats. At both sites, diurnal patterns of NEE among different months were very similar in shape but varied slightly in amplitude. NEE values were about zero during spring time. CO2 fluxes have been intensified after crop emerging from values of 3 to 7 µmol/s∙m2 for emission, and from 5 to 20 µmol/s∙m2 for sink. Stabilization of the fluxes has come at achieving plants height of 10-12 cm. Average NEE was negative only in June and July. Maximum uptake was observed in June with average values about 8 µmol CO2 m−2 s−1. Although different kind of crops were planted on the fields A and B, GPP dynamics was quite similar for both sites: after reaching the peak values at the mid of June, GPP decreased from 4 to 0.5 g C CO2 m-2 d-1 at the end of July. The difference in crops harvesting time that was equal two weeks did not significantly influence the daily

  13. Measurement of carbon dioxide fluxes in a free-air carbon dioxide enrichment experiment using the closed flux chamber technique

    DEFF Research Database (Denmark)

    Selsted, Merete Bang; Ambus, Per; Michelsen, Anders

    2011-01-01

    Carbon dioxide (CO2) fluxes, composing net ecosystem exchange (NEE), ecosystem respiration (ER), and soil respiration (SR) were measured in a temperate heathland exposed to elevated CO2 by the FACE (free-air carbon enrichment) technique, raising the atmospheric CO2 concentration from c. 380 μmol...... concentration, and the flux also decreased in FACE plots, to 0.79 times that at low concentration. Similar SR in control plots was decreased 0.94 times in control plots and 0.88 times in FACE plots. We found that a useful method to achieve stable and reproducible chamber headspace and soil CO2 concentration...... prior to commencement of flux measurements was to turn off the FACE system at least 10 min in advance. Within 10 min a new equilibrium was established between the soil and atmosphere, apparently due to CO2 degassing from the top soil. The observed increase in SR in response to increased CO2 persisted...

  14. Annual CO2 budget and seasonal CO2 exchange signals at a high Arctic permafrost site on Spitsbergen, Svalbard archipelago

    DEFF Research Database (Denmark)

    Luërs, J.; Westermann, Signe; Piel, K.

    2014-01-01

    The annual variability of CO2 exchange in most ecosystems is primarily driven by the activities of plants and soil microorganisms. However, little is known about the carbon balance and its controlling factors outside the growing season in Arctic regions dominated by soil freeze/thaw processes, long......-lasting snow cover, and several months of darkness. This study presents a complete annual cycle of the CO2 net ecosystem exchange (NEE) dynamics for a high Arctic tundra area at the west coast of Svalbard based on eddy covariance flux measurements. The annual cumulative CO2 budget is close to 0 g C m-2 yr-1......, but displays a strong seasonal variability. Four major CO2 exchange seasons have been identified. (1) During summer (snow-free ground), the CO2 exchange occurs mainly as a result of biological activity, with a dominance of strong CO2 assimilation by the ecosystem. (2) The autumn (snow-free ground or partly...

  15. The genus Solanum (Solanaceae in southern Africa: subgenus Leptostemonum, the introduced sections Acanthophora and Torva

    Directory of Open Access Journals (Sweden)

    W. G. Welman

    2003-12-01

    Full Text Available In the genus Solanum L. (Solanaceae, subgenus Leptostemonum (Dunal Bitter, section Acanthophora Dunal has four representatives in the Flora of southern Africa region (South Africa. Lesotho, Swaziland, Namibia. Botswana, namely  S. aculeatissimum Jacq.. S. capsicoides Allioni. S. mammosum L. (cultivated only and S. viarum Dunal. Section  Ton a Nees has two representatives in southern Africa, namely S.  chnsotriclium Schltdl. (S.  hispidum auctt. non Pers. and S.  ton um Sw.; both are naturalized weeds.  Solanum capsicoides, S. viarum and S.  torvum have not been listed before for southern Africa. All are introduced species native to the New World. Descriptions, discussions, illustrations and distribution maps of the naturalized species are presented, as well as keys to the species of both sections.

  16. Naproxen: from skunk work to scale-up

    CSIR Research Space (South Africa)

    Steenkamp, Lucia H

    2008-11-01

    Full Text Available for production of S- naproxen (ee > 10% S) from the hydrolysis of NEE: • NOVO 388; • NOVO 398; • Boehringer hog liver esterase; • Aspergillus niger (Fluka 62294); • Mucor miehei (Fluka 62298); • Aspergillus oryzae (Fluka 62285); • ESL001-01 • Chiro... 388 17.8 38 2.4 239 NOVO 398 8.4 70.6 6.2 189 Hog liver esterase 38 33 2.4 22 A niger lipase 4.4 43.4 2.6 4 Mucor miehei lipase 3 27.8 1.8 4 A oryzae lipase 5.2 68 5.5 6 ESL001-01 13.5 87 16.3 17 ChiroCLEC CR 40 99 >100 4 Slide 15 © CSIR 2006...

  17. Response of net ecosystem CO2 exchange and evapotranspiration of boreal forest ecosystems to projected future climate changes: results of a modeling study

    Science.gov (United States)

    Olchev, Alexander; Kurbatova, Julia

    2014-05-01

    It is presented the modeling results describing the possible response of net ecosystem exchange of CO2 (NEE), gross (GPP) and net (NPP) primary production, as well as evapotranspiration (ET) of spruce forest ecosystems situated at central part of European part of Russia at the southern boundary of boreal forest community to projected future changes of climatic conditions and forest species composition. A process-based MixFor-SVAT model (Olchev et al 2002, 2008, 2009) has been used to describe the CO2 and H2O fluxes under present and projected future climate conditions. The main advantage of MixFor-SVAT is its ability not only to describe seasonal and daily dynamics of total CO2 and H2O fluxes at an ecosystem level, but also to adequately estimate the contributions of soil, forest understorey, and various tree species in overstorey into total ecosystem fluxes taking into account their individual responses to changes in environmental conditions as well as the differences in structure and biophysical properties. Results of modeling experiments showed that projected changes of climate conditions (moderate scenario A1B IPCC) and forest species composition at the end of 21 century can lead to small increase of annual evapotranspiration as well as to growth of NEE, GPP and NPP of the forests in case if the projected increase in temperature and elevated CO2 in the atmosphere in future will be strictly balanced with growth of available nutrients and water in plant and soil. It is obvious that any deficit of e.g. nitrogen in leaves (due to reduced transpiration, nitrogen availability in soil, etc.) may lead to decreases in the photosynthesis and respiration rates of trees and, as a consequence, to decreases in the GPP and NEE of entire forest ecosystem. Conducted modeling experiments have demonstrated that a 20% reduction of available nitrogen in tree leaves in a monospesific spruce forest stand may result in a 14% decrease in NEE, a 8% decrease in NPP, and a 4% decrease in

  18. Improving SWAT for simulating water and carbon fluxes of forest ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Qichun; Zhang, Xuesong

    2016-11-01

    As a widely used watershed model for assessing impacts of anthropogenic and natural disturbances on water quantity and quality, the Soil and Water Assessment Tool (SWAT) has not been extensively tested in simulating water and carbon fluxes of forest ecosystems. Here, we examine SWAT simulations of evapotranspiration (ET), net primary productivity (NPP), net ecosystem exchange (NEE), and plant biomass at ten AmeriFlux forest sites across the U.S. We identify unrealistic radiation use efficiency (Bio_E), large leaf to biomass fraction (Bio_LEAF), and missing phosphorus supply from parent material weathering as the primary causes for the inadequate performance of the default SWAT model in simulating forest dynamics. By further revising the relevant parameters and processes, SWAT’s performance is substantially improved. Based on the comparison between the improved SWAT simulations and flux tower observations, we discuss future research directions for further enhancing model parameterization and representation of water and carbon cycling for forests.

  19. CSSF MIMO RADAR: Low-Complexity Compressive Sensing Based MIMO Radar That Uses Step Frequency

    CERN Document Server

    Yu, Yao; Poor, H Vincent

    2011-01-01

    A new approach is proposed, namely CSSF MIMO radar, which applies the technique of step frequency (SF) to compressive sensing (CS) based multi-input multi-output (MIMO) radar. The proposed approach enables high resolution range, angle and Doppler estimation, while transmitting narrowband pulses. The problem of joint angle-Doppler-range estimation is first formulated to fit the CS framework, i.e., as an L1 optimization problem. Direct solution of this problem entails high complexity as it employs a basis matrix whose construction requires discretization of the angle-Doppler-range space. Since high resolution requires fine space discretization, the complexity of joint range, angle and Doppler estimation can be prohibitively high. For the case of slowly moving targets, a technique is proposed that achieves significant complexity reduction by successively estimating angle-range and Doppler in a decoupled fashion and by employing initial estimates obtained via matched filtering to further reduce the space that nee...

  20. Weeds optimally grow in peat swamp after burning

    Directory of Open Access Journals (Sweden)

    P.D. Susanti

    2014-07-01

    Full Text Available After clearing land by burning the peat, then the weeds and undergrowth will flourish. Even sometimes, the weeds are eventually burned again. Weed is known as a destroyer plant that has to be controlled. Through proper treatment, the existing weeds in peatlands can be potentiallly exploited. The purpose of this study was to determine the calorific value of briquettes as one of peatland weeds utilization. The results showed that the calorific value ranged from 2,492 cal/g to 5,230 cal/g. The lowest calorific value was on ‘teki kecil’ grass (Scirpus grossus Lf, while the highest calorific value was observed for ‘bantalaki grass’ (Hymenachne amplexicaulis Nees. The high calorific value of the peat weeds are potential for biomass briquettes raw materials. The utilization and use of peat weed briquettes as a raw materials expected can reduce land degradation due to peat swamp burning