Moss and vascular plant indices in Ohio wetlands have similar environmental predictors

Science.gov (United States)

Stapanian, Martin A.; Schumacher, William; Gara, Brian; Adams, Jean V.; Viau, Nick

2016-01-01

Mosses and vascular plants have been shown to be reliable indicators of wetland habitat delineation and environmental quality. Knowledge of the best ecological predictors of the quality of wetland moss and vascular plant communities may determine if similar management practices would simultaneously enhance both populations. We used Akaike's Information Criterion to identify models predicting a moss quality assessment index (MQAI) and a vascular plant index of biological integrity based on floristic quality (VIBI-FQ) from 27 emergent and 13 forested wetlands in Ohio, USA. The set of predictors included the six metrics from a wetlands disturbance index (ORAM) and two landscape development intensity indices (LDIs). The best single predictor of MQAI and one of the predictors of VIBI-FQ was an ORAM metric that assesses habitat alteration and disturbance within the wetland, such as mowing, grazing, and agricultural practices. However, the best single predictor of VIBI-FQ was an ORAM metric that assessed wetland vascular plant communities, interspersion, and microtopography. LDIs better predicted MQAI than VIBI-FQ, suggesting that mosses may either respond more rapidly to, or recover more slowly from, anthropogenic disturbance in the surrounding landscape than vascular plants. These results supported previous predictive studies on amphibian indices and metrics and a separate vegetation index, indicating that similar wetland management practices may result in qualitatively the same ecological response for three vastly different wetland biological communities (amphibians, vascular plants, and mosses).

Crystallization of Doc and the Phd–Doc toxin–antitoxin complex

International Nuclear Information System (INIS)

Garcia-Pino, Abel; Dao-Thi, Minh-Hoa; Gazit, Ehud; Magnuson, Roy David; Wyns, Lode; Loris, Remy

2008-01-01

Crystals of bacteriophage P1 Doc were grown in the free state, in complex with a 22-amino-acid C-terminal peptide of Phd and in complex with full-length Phd. The phd/doc addiction system is responsible for the stable inheritance of lysogenic bacteriophage P1 in its plasmidic form in Escherichia coli and is the archetype of a family of bacterial toxin–antitoxin modules. The His66Tyr mutant of Doc (Doc H66Y ) was crystallized in space group P2 1 , with unit-cell parameters a = 53.1, b = 198.0, c = 54.1 Å, β = 93.0°. These crystals diffracted to 2.5 Å resolution and probably contained four dimers of Doc in the asymmetric unit. Doc H66Y in complex with a 22-amino-acid C-terminal peptide of Phd (Phd 52-73Se ) was crystallized in space group C2, with unit-cell parameters a = 111.1, b = 38.6, c = 63.3 Å, β = 99.3°, and diffracted to 1.9 Å resolution. Crystals of the complete wild-type Phd–Doc complex belonged to space group P3 1 21 or P3 2 21, had an elongated unit cell with dimensions a = b = 48.9, c = 354.9 Å and diffracted to 2.4 Å resolution using synchrotron radiation

Use of gold nanoparticles to detect water uptake in vascular plants.

Science.gov (United States)

Hwang, Bae Geun; Ahn, Sungsook; Lee, Sang Joon

2014-01-01

Direct visualization of water-conducting pathways and sap flows in xylem vessels is important for understanding the physiology of vascular plants and their sap ascent. Gold nanoparticles (AuNPs) combined with synchrotron X-ray imaging technique is a new promising tool for investigating plant hydraulics in opaque xylem vessels of vascular plants. However, in practical applications of AuNPs for real-time quantitative visualization of sap flows, their interaction with a vascular network needs to be verified in advance. In this study, the effect of AuNPs on the water-refilling function of xylem vessels is experimentally investigated with three monocot species. Discrepancy in the water uptakes starts to appear at about 20 min to 40 min after the supply of AuNP solution to the test plant by the possible gradual accumulation of AuNPs on the internal structures of vasculature. However conclusively, it is observed that the water-refilling speeds in individual xylem vessels are virtually unaffected by hydrophilically surface-modified AuNPs (diameter ∼20 nm). Therefore, the AuNPs can be effectively used as flow tracers in the xylem vessels in the first 20∼30 min without any physiological barrier. As a result, AuNPs are found to be useful for visualizing various fluid dynamic phenomena occurring in vascular plants.

Crystallization of Doc and the Phd-Doc toxin-antitoxin complex.

Science.gov (United States)

Garcia-Pino, Abel; Dao-Thi, Minh-Hoa; Gazit, Ehud; Magnuson, Roy David; Wyns, Lode; Loris, Remy

2008-11-01

The phd/doc addiction system is responsible for the stable inheritance of lysogenic bacteriophage P1 in its plasmidic form in Escherichia coli and is the archetype of a family of bacterial toxin-antitoxin modules. The His66Tyr mutant of Doc (Doc(H66Y)) was crystallized in space group P2(1), with unit-cell parameters a = 53.1, b = 198.0, c = 54.1 A, beta = 93.0 degrees . These crystals diffracted to 2.5 A resolution and probably contained four dimers of Doc in the asymmetric unit. Doc(H66Y) in complex with a 22-amino-acid C-terminal peptide of Phd (Phd(52-73Se)) was crystallized in space group C2, with unit-cell parameters a = 111.1, b = 38.6, c = 63.3 A, beta = 99.3 degrees , and diffracted to 1.9 A resolution. Crystals of the complete wild-type Phd-Doc complex belonged to space group P3(1)21 or P3(2)21, had an elongated unit cell with dimensions a = b = 48.9, c = 354.9 A and diffracted to 2.4 A resolution using synchrotron radiation.

Sources for increased DOC-concentrations in the groundwater downstream of the landfill Hohne (DEA); Ursachen erhoehter DOC-Konzentrationen im Grundwasserabstrom am Beispiel der Deponie Hohne (DEA)

Energy Technology Data Exchange (ETDEWEB)

Bahlmann, E.; Seifert, R. [Hamburg Univ. (Germany). Inst. fuer Geologie; Eschenbach, A.; Kleinschmidt, V. [Hamburg Univ. (Germany). Inst. fuer Bodenkunde

2017-08-15

Construction waste together with drilling mud and oil-contaminated soil had been deposited in the landfill Hohne from 1971. Four groundwater monitoring sites had been installed: one monitoring site upstream and three sites downstream of the landfill in three different directions. Downstream of the landfill increased concentrations of chloride, sulphate, sodium and DOC (dissolved organic carbon) had been measured over a period of years. Particularly the source of the DOC has remained unclear. Assumptions were (i) leaking of contaminants from the landfill and degradation under the landfill by microbes or plants or (ii) leaching of DOC from the soil under the landfill caused by a change in the redox potential. The determination of the DOC source was the major subject of this study.

A DOC coagulant, gypsum treatment can simultaneously reduce As, Cd and Pb uptake by medicinal plants grown in contaminated soil.

Science.gov (United States)

Kim, Hyuck Soo; Seo, Byoung-Hwan; Kuppusamy, Saranya; Lee, Yong Bok; Lee, Jae-Hwang; Yang, Jae-E; Owens, Gary; Kim, Kwon-Rae

2018-02-01

The efficiency of gypsum, as a dissolved organic carbon (DOC) coagulator, for the simultaneous immobilization of two heavy metals (Cd and Pb) and one metalloid (As) in agricultural soils near an abandoned mining site was examined. The agricultural soil was defined as long-term contaminated as As (1540mgkg -1 ), Cd (55mgkg -1 ) and Pb (1283mgkg -1 ) concentrations exceeded the Korean guideline values for As (25mgkg -1 ), Cd (4mgkg -1 ), and Pb (200mgkg -1 ). Gypsum was incorporated into the contaminated soil at 3% (w/w). In comparison two commonly using immobilizing agents (lime and compost), together with a mixture (lime+gypsum) were also included in the pot trial for the cultivation of two medical plants (A. gigas and A. macrocephala) and to evaluate the effectiveness of gypsum on As, Cd and Pb immobilization. The results showed that even though pH change-induced immobilizing agents such as lime were more effective than gypsum at immobilizing Cd and Pb, addition of gypsum also effectively reduced heavy metal phytoavailability as indicated by decreases in the concentration of Cd and Pb in medicinal plants. Furthermore, gypsum and gypsum+ lime were also most effective in reducing As concentrations in both plants studied. This was mainly attributed to significant decreases in soil DOC (48-64%) when gypsum and gypsum+lime were applied to the soil. Consequently, it was concluded that enhanced DOC coagulation with gypsum, could be considered as a promising technique for the immobilization of both metals (Cd and Pb) and metalloids (As) in agricultural soils. Copyright © 2017 Elsevier Inc. All rights reserved.

Toxicity, Uptake, and Translocation of Engineered Nanomaterials in Vascular plants.

Science.gov (United States)

Miralles, Pola; Church, Tamara L; Harris, Andrew T

2012-09-04

To exploit the promised benefits of engineered nanomaterials, it is necessary to improve our knowledge of their bioavailability and toxicity. The interactions between engineered nanomaterials and vascular plants are of particular concern, as plants closely interact with soil, water, and the atmosphere, and constitute one of the main routes of exposure for higher species, i.e. accumulation through the food chain. A review of the current literature shows contradictory evidence on the phytotoxicity of engineered nanomaterials. The mechanisms by which engineered nanomaterials penetrate plants are not well understood, and further research on their interactions with vascular plants is required to enable the field of phytotoxicology to keep pace with that of nanotechnology, the rapid evolution of which constantly produces new materials and applications that accelerate the environmental release of nanomaterials.

Doc Immelman

African Journals Online (AJOL)

Owner

Baarde, briewe en barmhartigheid (2013) verskyn as 'n laaste saluut aan die Namibiese skrywer,. Doc Immelman, ná sy dood in Maart 2013. Hierdie rubriekbundel is Immelman se twee- de versameling rubrieke ná Ruacana tot Rosh. Pinah (2011). Daniel Ferdinand (Doc) Immel- man was onder meer 'n rubriekskrywer, dig-.

Diversity of vascular plants of Piestany and surroundings

International Nuclear Information System (INIS)

Penzesova, A.; Galusova, T.

2013-01-01

In the present work is a summary of the results of floristic research aimed at determining diversity of vascular plants of Piestany and its surroundings. Plant taxa we determined using the designation keys. We have compiled a list of plant species occurring in the monitored area, we evaluated the selected botanical-phytogeographical characteristics of flora, we've put together a list of local protected, endangered and rare species and a list of local invasive and expansive species according to sources. (Authors)

The mitochondrial genome of the lycophyte Huperzia squarrosa: the most archaic form in vascular plants.

Science.gov (United States)

Liu, Yang; Wang, Bin; Cui, Peng; Li, Libo; Xue, Jia-Yu; Yu, Jun; Qiu, Yin-Long

2012-01-01

Mitochondrial genomes have maintained some bacterial features despite their residence within eukaryotic cells for approximately two billion years. One of these features is the frequent presence of polycistronic operons. In land plants, however, it has been shown that all sequenced vascular plant chondromes lack large polycistronic operons while bryophyte chondromes have many of them. In this study, we provide the completely sequenced mitochondrial genome of a lycophyte, from Huperzia squarrosa, which is a member of the sister group to all other vascular plants. The genome, at a size of 413,530 base pairs, contains 66 genes and 32 group II introns. In addition, it has 69 pseudogene fragments for 24 of the 40 protein- and rRNA-coding genes. It represents the most archaic form of mitochondrial genomes of all vascular plants. In particular, it has one large conserved gene cluster containing up to 10 ribosomal protein genes, which likely represents a polycistronic operon but has been disrupted and greatly reduced in the chondromes of other vascular plants. It also has the least rearranged gene order in comparison to the chondromes of other vascular plants. The genome is ancestral in vascular plants in several other aspects: the gene content resembling those of charophytes and most bryophytes, all introns being cis-spliced, a low level of RNA editing, and lack of foreign DNA of chloroplast or nuclear origin.

Publishing datasets with eSciDoc and panMetaDocs

Science.gov (United States)

Ulbricht, D.; Klump, J.; Bertelmann, R.

2012-04-01

Currently serveral research institutions worldwide undertake considerable efforts to have their scientific datasets published and to syndicate them to data portals as extensively described objects identified by a persistent identifier. This is done to foster the reuse of data, to make scientific work more transparent, and to create a citable entity that can be referenced unambigously in written publications. GFZ Potsdam established a publishing workflow for file based research datasets. Key software components are an eSciDoc infrastructure [1] and multiple instances of the data curation tool panMetaDocs [2]. The eSciDoc repository holds data objects and their associated metadata in container objects, called eSciDoc items. A key metadata element in this context is the publication status of the referenced data set. PanMetaDocs, which is based on PanMetaWorks [3], is a PHP based web application that allows to describe data with any XML-based metadata schema. The metadata fields can be filled with static or dynamic content to reduce the number of fields that require manual entries to a minimum and make use of contextual information in a project setting. Access rights can be applied to set visibility of datasets to other project members and allow collaboration on and notifying about datasets (RSS) and interaction with the internal messaging system, that was inherited from panMetaWorks. When a dataset is to be published, panMetaDocs allows to change the publication status of the eSciDoc item from status "private" to "submitted" and prepare the dataset for verification by an external reviewer. After quality checks, the item publication status can be changed to "published". This makes the data and metadata available through the internet worldwide. PanMetaDocs is developed as an eSciDoc application. It is an easy to use graphical user interface to eSciDoc items, their data and metadata. It is also an application supporting a DOI publication agent during the process of

The plant vascular system: Evolution, development and functions

Science.gov (United States)

William J. Lucas; Andrew Groover; Raffael Lichtenberger; Kaori Furuta; Shri-Ram Yadav; Yka Helariutta; Xin-Qiang He; Hiroo Fukuda; Julie Kang; Siobhan M. Brady; John W. Patrick; John Sperry; Akiko Yoshida; Ana-Flor Lopez-Millan; Michael A. Grusak; Pradeep Kachroo

2013-01-01

The emergence of the tracheophyte-based vascular system of land plants had major impacts on the evolution of terrestrial biology, in general, through its role in facilitating the development of plants with increased stature, photosynthetic output, and ability to colonize a greatly expanded range of environmental habitats. Recently, considerable progress has been made...

Aboveground persistence of vascular plants in relationship to the levels of airborne nutrient deposition

NARCIS (Netherlands)

Hendriks, R.J.J.; Ozinga, W.A.; Berg, van den L.J.L.; Noordwijk, E.; Schaminee, J.H.J.; Groenendael, van J.M.

2014-01-01

This paper examines whether high atmospheric nitrogen deposition affects aboveground persistence of vascular plants. We combined information on local aboveground persistence of vascular plants in 245 permanent plots in the Netherlands with estimated level of nitrogen deposition at the time of

Temporal deconvolution of vascular plant signatures delivered to coastal sediments

Science.gov (United States)

Vonk, J.; Drenzek, N. J.; Hughen, K. A.; Stanley, R.; Montluçon, D. B.; McIntyre, C.; Southon, J. R.; Santos, G.; Andersson, A.; Sköld, M.; Eglinton, T. I.

2017-12-01

Presently, relatively little is known about the amount of time that lapses between the photosynthetic fixation of carbon by vascular land plants and its incorporation into the marine sedimentary record. It is clear that there are multiple potential intermediate storage pools and transport trajectories that vascular plant carbon may experience, and the age of vascular plant carbon accumulating in marine sediments will reflect these different pre-depositional histories. Here we use molecular-level radiocarbon (14C) analysis to develop down-core 14C profiles for higher plant leaf wax-derived fatty acids isolated from sediments from three sites across a 60-degrees latitudinal gradient (Cariaco Basin, Saanich Inlet, and Mackenzie Delta). The sediment profiles were used as a direct measure of the storage and transport times experienced by these biomolecular tracer compounds. Residence times are evaluated by comparing these records to the 14C history of atmospheric CO2. Using a modeling framework, we conclude that there is, in addition to a variable "young" pool, a millennial pool of compounds that consists of 49-78 % of the fractional contribution of organic carbon (OC) that exhibits variable ages for the different depositional settings. For the Mackenzie Delta sediments, we find a mean age of the millennial pool of 28 ky, suggesting pre-aging in permafrost soils, whereas the millennial pool in Saanich Inlet and Cariaco Basin sediments is younger with 7.9 and 2.4-3.2 ky, respectively, suggesting limited storage in terrestrial reservoirs. The "young" pool, conditionally defined as vascular plant C in deltaic and marine settings undergoes pre-aging in terrestrial reservoirs. The age distribution, reflecting storage and transport times, depends on landscape-specific factors such as local topography, hydrographic characteristics, and degree of soil build-up and preservation.

Double-filter identification of vascular-expressed genes using Arabidopsis plants with vascular hypertrophy and hypotrophy.

Science.gov (United States)

Ckurshumova, Wenzislava; Scarpella, Enrico; Goldstein, Rochelle S; Berleth, Thomas

2011-08-01

Genes expressed in vascular tissues have been identified by several strategies, usually with a focus on mature vascular cells. In this study, we explored the possibility of using two opposite types of altered tissue compositions in combination with a double-filter selection to identify genes with a high probability of vascular expression in early organ primordia. Specifically, we generated full-transcriptome microarray profiles of plants with (a) genetically strongly reduced and (b) pharmacologically vastly increased vascular tissues and identified a reproducible cohort of 158 transcripts that fulfilled the dual requirement of being underrepresented in (a) and overrepresented in (b). In order to assess the predictive value of our identification scheme for vascular gene expression, we determined the expression patterns of genes in two unbiased subsamples. First, we assessed the expression patterns of all twenty annotated transcription factor genes from the cohort of 158 genes and found that seventeen of the twenty genes were preferentially expressed in leaf vascular cells. Remarkably, fifteen of these seventeen vascular genes were clearly expressed already very early in leaf vein development. Twelve genes with published leaf expression patterns served as a second subsample to monitor the representation of vascular genes in our cohort. Of those twelve genes, eleven were preferentially expressed in leaf vascular tissues. Based on these results we propose that our compendium of 158 genes represents a sample that is highly enriched for genes expressed in vascular tissues and that our approach is particularly suited to detect genes expressed in vascular cell lineages at early stages of their inception. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

[Diversity and distribution of the threatened medicinal vascular plants in Lancang].

Science.gov (United States)

Chi, Xiu-Lian; Yuan, Yi-Kai; Fang, Bo; Zhang, Xiao-Bo; Yang, Han-Yu; Zhao, Zhi-Ping; Li, Guo; Fu, Kai-Cong; Guo, Lan-Ping; Huang, Lu-Qi

2017-11-01

The rich diversity in medicinal plants provides an important material basic for the development of Traditional Chinese medicine in China. It is important to explore the present situation of medicinal plants within special regions in order to provide scientific instructions for their sustainable protection and exploitation and utilization. In this study, we carried out the field survey according to the guideline of national survey of Chinese material medica resources and the guideline of plant species diversity survey and estimation at county level with the line transect method. With the field surveyed data, we explored the diversity and distribution of the threatened medicinal vascular plants in Lancang. We found that there were 33 species of the threatened medicinal vascular plants in this county. These species were from 23 genera and 17 families, and were composed of one critical endangered, 10 endangered and 22 vulnerable species. They were widely distributed across the whole county and were most concentrated in the town of Nuozhadu, Fazhanhe, Nuofu and Zhutang, which were located in the southeastern, southwestern and western of Lancang, respectively. We also found that the plant species richness followed a unimodal pattern along elevation. In addition, we found that the areas of Nuozhadu Nature Reserve in Lancang only covered six threatened medicinal vascular plants, while most of the regions with high species richness were not well protected. Therefore, we proposed to make more efforts to improve the protection measurements in order to better protect and utilize the medicinal plants in Lancang. Copyright© by the Chinese Pharmaceutical Association.

Managing peatland vegetation for drinking water treatment.

Science.gov (United States)

Ritson, Jonathan P; Bell, Michael; Brazier, Richard E; Grand-Clement, Emilie; Graham, Nigel J D; Freeman, Chris; Smith, David; Templeton, Michael R; Clark, Joanna M

2016-11-18

Peatland ecosystem services include drinking water provision, flood mitigation, habitat provision and carbon sequestration. Dissolved organic carbon (DOC) removal is a key treatment process for the supply of potable water downstream from peat-dominated catchments. A transition from peat-forming Sphagnum moss to vascular plants has been observed in peatlands degraded by (a) land management, (b) atmospheric deposition and (c) climate change. Here within we show that the presence of vascular plants with higher annual above-ground biomass production leads to a seasonal addition of labile plant material into the peatland ecosystem as litter recalcitrance is lower. The net effect will be a smaller litter carbon pool due to higher rates of decomposition, and a greater seasonal pattern of DOC flux. Conventional water treatment involving coagulation-flocculation-sedimentation may be impeded by vascular plant-derived DOC. It has been shown that vascular plant-derived DOC is more difficult to remove via these methods than DOC derived from Sphagnum, whilst also being less susceptible to microbial mineralisation before reaching the treatment works. These results provide evidence that practices aimed at re-establishing Sphagnum moss on degraded peatlands could reduce costs and improve efficacy at water treatment works, offering an alternative to 'end-of-pipe' solutions through management of ecosystem service provision.

Diversity of vascular plants of Piestany and surroundings (presentation)

International Nuclear Information System (INIS)

Penzesova, A.; Galusova, T.

2013-01-01

In this presentation is a summary of the results of floristic research aimed at determining diversity of vascular plants of Piestany and its surroundings. Plant taxa we determined using the designation keys. We have compiled a list of plant species occurring in the monitored area, we evaluated the selected botanical-phytogeographical characteristics of flora, we've put together a list of local protected, endangered and rare species and a list of local invasive and expansive species according to sources. (Authors)

Bilaterally symmetric axes with rhizoids composed the rooting structure of the common ancestor of vascular plants.

Science.gov (United States)

Hetherington, Alexander J; Dolan, Liam

2018-02-05

There are two general types of rooting systems in extant land plants: gametophyte rhizoids and sporophyte root axes. These structures carry out the rooting function in the free-living stage of almost all land plant gametophytes and sporophytes, respectively. Extant vascular plants develop a dominant, free-living sporophyte on which roots form, with the exception of a small number of taxa that have secondarily lost roots. However, fossil evidence indicates that early vascular plants did not develop sporophyte roots. We propose that the common ancestor of vascular plants developed a unique rooting system-rhizoidal sporophyte axes. Here we present a synthesis and reinterpretation of the rootless sporophytes of Horneophyton lignieri , Aglaophyton majus , Rhynia gwynne-vaughanii and Nothia aphylla preserved in the Rhynie chert. We show that the sporophyte rooting structures of all four plants comprised regions of plagiotropic (horizontal) axes that developed unicellular rhizoids on their underside. These regions of axes with rhizoids developed bilateral symmetry making them distinct from the other regions which were radially symmetrical. We hypothesize that rhizoidal sporophyte axes constituted the rooting structures in the common ancestor of vascular plants because the phylogenetic positions of these plants span the origin of the vascular lineage.This article is part of a discussion meeting issue 'The Rhynie cherts: our earliest terrestrial ecosystem revisited'. © 2017 The Authors.

The compact Selaginella genome identifies changes in gene content associated with the evolution of vascular plants

Energy Technology Data Exchange (ETDEWEB)

Grigoriev, Igor V.; Banks, Jo Ann; Nishiyama, Tomoaki; Hasebe, Mitsuyasu; Bowman, John L.; Gribskov, Michael; dePamphilis, Claude; Albert, Victor A.; Aono, Naoki; Aoyama, Tsuyoshi; Ambrose, Barbara A.; Ashton, Neil W.; Axtell, Michael J.; Barker, Elizabeth; Barker, Michael S.; Bennetzen, Jeffrey L.; Bonawitz, Nicholas D.; Chapple, Clint; Cheng, Chaoyang; Correa, Luiz Gustavo Guedes; Dacre, Michael; DeBarry, Jeremy; Dreyer, Ingo; Elias, Marek; Engstrom, Eric M.; Estelle, Mark; Feng, Liang; Finet, Cedric; Floyd, Sandra K.; Frommer, Wolf B.; Fujita, Tomomichi; Gramzow, Lydia; Gutensohn, Michael; Harholt, Jesper; Hattori, Mitsuru; Heyl, Alexander; Hirai, Tadayoshi; Hiwatashi, Yuji; Ishikawa, Masaki; Iwata, Mineko; Karol, Kenneth G.; Koehler, Barbara; Kolukisaoglu, Uener; Kubo, Minoru; Kurata, Tetsuya; Lalonde, Sylvie; Li, Kejie; Li, Ying; Litt, Amy; Lyons, Eric; Manning, Gerard; Maruyama, Takeshi; Michael, Todd P.; Mikami, Koji; Miyazaki, Saori; Morinaga, Shin-ichi; Murata, Takashi; Mueller-Roeber, Bernd; Nelson, David R.; Obara, Mari; Oguri, Yasuko; Olmstead, Richard G.; Onodera, Naoko; Petersen, Bent Larsen; Pils, Birgit; Prigge, Michael; Rensing, Stefan A.; Riano-Pachon, Diego Mauricio; Roberts, Alison W.; Sato, Yoshikatsu; Scheller, Henrik Vibe; Schulz, Burkhard; Schulz, Christian; Shakirov, Eugene V.; Shibagaki, Nakako; Shinohara, Naoki; Shippen, Dorothy E.; Sorensen, Iben; Sotooka, Ryo; Sugimoto, Nagisa; Sugita, Mamoru; Sumikawa, Naomi; Tanurdzic, Milos; Theilsen, Gunter; Ulvskov, Peter; Wakazuki, Sachiko; Weng, Jing-Ke; Willats, William W.G.T.; Wipf, Daniel; Wolf, Paul G.; Yang, Lixing; Zimmer, Andreas D.; Zhu, Qihui; Mitros, Therese; Hellsten, Uffe; Loque, Dominique; Otillar, Robert; Salamov, Asaf; Schmutz, Jeremy; Shapiro, Harris; Lindquist, Erika; Lucas, Susan; Rokhsar, Daniel

2011-04-28

We report the genome sequence of the nonseed vascular plant, Selaginella moellendorffii, and by comparative genomics identify genes that likely played important roles in the early evolution of vascular plants and their subsequent evolution

Vascular plant-mediated controls on atmospheric carbon assimilation and peat carbon decomposition under climate change.

Science.gov (United States)

Gavazov, Konstantin; Albrecht, Remy; Buttler, Alexandre; Dorrepaal, Ellen; Garnett, Mark H; Gogo, Sebastien; Hagedorn, Frank; Mills, Robert T E; Robroek, Bjorn J M; Bragazza, Luca

2018-03-23

Climate change can alter peatland plant community composition by promoting the growth of vascular plants. How such vegetation change affects peatland carbon dynamics remains, however, unclear. In order to assess the effect of vegetation change on carbon uptake and release, we performed a vascular plant-removal experiment in two Sphagnum-dominated peatlands that represent contrasting stages of natural vegetation succession along a climatic gradient. Periodic measurements of net ecosystem CO 2 exchange revealed that vascular plants play a crucial role in assuring the potential for net carbon uptake, particularly with a warmer climate. The presence of vascular plants, however, also increased ecosystem respiration, and by using the seasonal variation of respired CO 2 radiocarbon (bomb- 14 C) signature we demonstrate an enhanced heterotrophic decomposition of peat carbon due to rhizosphere priming. The observed rhizosphere priming of peat carbon decomposition was matched by more advanced humification of dissolved organic matter, which remained apparent beyond the plant growing season. Our results underline the relevance of rhizosphere priming in peatlands, especially when assessing the future carbon sink function of peatlands undergoing a shift in vegetation community composition in association with climate change. © 2018 John Wiley & Sons Ltd.

Vascular Plants of the Hanford Site

International Nuclear Information System (INIS)

Sackschewsky, Michael R.; Downs, Janelle L.

2001-01-01

This report provides an updated listing of the vascular plants present on and near the U.S. Department of Energy Hanford Site. This document is an update of a listing of plants prepared by Sackschewdky et al. in 1992. Since that time there has been a significant increase in the botanical knowledge of the Hanford Site. The present listing is based on an examination of herbarium collections held at PNNL, at WSU-Tri Cities, WSU-Pullman, Brigham Young University, and The University of Washington, and on examination of ecological literature derived from the Hanford and Benton county areas over the last 100 years. Based on the most recent analysis, there are approximately 725 different plant species that have been documented on or around the Hanford Site. This represents an approximate 20% increase in the number of species reported within Sackschewsky et al. (1992). This listing directly supports DOE and contractor efforts to assess the potential impacts of Hanford Site operations

Mapping and Quantification of Vascular Branching in Plants, Animals and Humans by VESGEN Software

Science.gov (United States)

Parsons-Wingerter, P. A.; Vickerman, M. B.; Keith, P. A.

2010-01-01

Humans face daunting challenges in the successful exploration and colonization of space, including adverse alterations in gravity and radiation. The Earth-determined biology of plants, animals and humans is significantly modified in such extraterrestrial environments. One physiological requirement shared by larger plants and animals with humans is a complex, highly branching vascular system that is dynamically responsive to cellular metabolism, immunological protection and specialized cellular/tissue function. VESsel GENeration (VESGEN) Analysis has been developed as a mature beta version, pre-release research software for mapping and quantification of the fractal-based complexity of vascular branching. Alterations in vascular branching pattern can provide informative read-outs of altered vascular regulation. Originally developed for biomedical applications in angiogenesis, VESGEN 2D has provided novel insights into the cytokine, transgenic and therapeutic regulation of angiogenesis, lymphangiogenesis and other microvascular remodeling phenomena. Vascular trees, networks and tree-network composites are mapped and quantified. Applications include disease progression from clinical ophthalmic images of the human retina; experimental regulation of vascular remodeling in the mouse retina; avian and mouse coronary vasculature, and other experimental models in vivo. We envision that altered branching in the leaves of plants studied on ISS such as Arabidopsis thaliana cans also be analyzed.

Sources for increased DOC-concentrations in the groundwater downstream of the landfill Hohne (DEA)

International Nuclear Information System (INIS)

Bahlmann, E.; Seifert, R.; Eschenbach, A.; Kleinschmidt, V.

2017-08-01

Construction waste together with drilling mud and oil-contaminated soil had been deposited in the landfill Hohne from 1971. Four groundwater monitoring sites had been installed: one monitoring site upstream and three sites downstream of the landfill in three different directions. Downstream of the landfill increased concentrations of chloride, sulphate, sodium and DOC (dissolved organic carbon) had been measured over a period of years. Particularly the source of the DOC has remained unclear. Assumptions were (i) leaking of contaminants from the landfill and degradation under the landfill by microbes or plants or (ii) leaching of DOC from the soil under the landfill caused by a change in the redox potential. The determination of the DOC source was the major subject of this study.

Rare vascular plant species at risk : recovery by seeding?

NARCIS (Netherlands)

Pegtel, Dick M.

. Rare vascular plant species are endangered worldwide. Population losses are most commonly caused by human-related factors. Conservation management seeks to halt this adverse trend and if possible, to enhance long-lasting self-sustainable populations. In general, rare species are poorly recruited

VASCULAR PLANTS AS ENGINEERS OF OXYGEN IN AQUATIC SYSTEMS

Science.gov (United States)

The impact of organisms on oxygen is one of the most dramatic examples of ecosystem engineering on Earth. In aquatic systems, which have much lower oxygen concentrations than the atmosphere, vascular aquatic plants can affect oxygen concentrations significantly not only on long t...

Modelling impacts of temperature, and acidifying and eutrophying deposition on DOC trends

Science.gov (United States)

Sawicka, Kasia; Rowe, Ed; Evans, Chris; Monteith, Don; Vanguelova, Elena; Wade, Andrew; Clark, Joanna

2017-04-01

Surface water dissolved organic carbon (DOC) concentrations in large parts of the northern hemisphere have risen over the past three decades, raising concern about enhanced contributions of carbon to the atmosphere and seas and oceans. The effect of declining acid deposition has been identified as a key control on DOC trends in soil and surface waters, since pH and ionic strength affect sorption and desorption of DOC. However, since DOC is derived mainly from recently-fixed carbon, and organic matter decomposition rates are considered sensitive to temperature, uncertainty persists regarding the extent to the relative importance of different drivers that affect these upward trends. We ran the dynamic model MADOC (Model of Acidity and Soil Organic Carbon) for a range of UK soils (podzols, gleysols and peatland), for which the time-series were available, to consider the likely relative importance of decreased deposition of sulphate and chloride, accumulation of reactive N, and higher temperatures, on DOC production in different soils. Modelled patterns of DOC change generally agreed favourably with measurements collated over 10-20 years, but differed markedly between sites. While the acidifying effect of sulphur deposition appeared to be the predominant control on the observed soil water DOC trends in all the soils considered other than a blanket peat, the model suggested that over the long term, the effects of nitrogen deposition on N-limited soils may have been sufficient to elevate the DOC recovery trajectory significantly. The second most influential cause of rising DOC in the model simulations was N deposition in ecosystems that are N-limited and respond with stimulated plant growth. Although non-marine chloride deposition made some contribution to acidification and recovery, it was not amongst the main drivers of DOC change. Warming had almost no effect on modelled historic DOC trends, but may prove to be a significant driver of DOC in future via its influence

RAINBIO: a mega-database of tropical African vascular plants distributions

Directory of Open Access Journals (Sweden)

Dauby Gilles

2016-11-01

Full Text Available The tropical vegetation of Africa is characterized by high levels of species diversity but is undergoing important shifts in response to ongoing climate change and increasing anthropogenic pressures. Although our knowledge of plant species distribution patterns in the African tropics has been improving over the years, it remains limited. Here we present RAINBIO, a unique comprehensive mega-database of georeferenced records for vascular plants in continental tropical Africa. The geographic focus of the database is the region south of the Sahel and north of Southern Africa, and the majority of data originate from tropical forest regions. RAINBIO is a compilation of 13 datasets either publicly available or personal ones. Numerous in depth data quality checks, automatic and manual via several African flora experts, were undertaken for georeferencing, standardization of taxonomic names and identification and merging of duplicated records. The resulting RAINBIO data allows exploration and extraction of distribution data for 25,356 native tropical African vascular plant species, which represents ca. 89% of all known plant species in the area of interest. Habit information is also provided for 91% of these species.

Species richness of vascular plants, bryophytes, and lichens along an altitudinal gradient in western Norway

Science.gov (United States)

Grytnes, John Arvid; Heegaard, Einar; Ihlen, Per G.

2006-05-01

Species richness patterns of ground-dwelling vascular plants, bryophytes, and lichens were compared along an altitudinal gradient (310-1135 m a.s.l.), in western Norway. Total species richness peaked at intermediate altitudes, vascular plant species richness peaked immediately above the forest limit (at 600-700 m a.s.l.), bryophyte species richness had no statistically significant trend, whereas lichen richness increased from the lowest point and up to the forest limit, with no trend above. It is proposed that the pattern in vascular plant species richness is enhanced by an ecotone effect. Bryophyte species richness responds to local scale factors whereas the lichen species richness may be responding to the shading from the forest trees.

Flora of vascular plants in the Chilgapsan Provincial Park, Korea

Directory of Open Access Journals (Sweden)

Ro-Young Lee

2014-09-01

Full Text Available The flora of Chilgapsan Provincial Park in Cheongyang-gun (Chungcheongnam-do, Korea was surveyed from 2000 to 2014. In 19 field surveys, vascular plants were revealed 490 taxa belonging to 97 families, 309 genera, 433 species, four subspecies, 48 varieties, and five forms. Plants of various categories were discovered in this study. For the Korean endemic plants 15 taxa were recorded, and 11 taxa designated by the Korean Forest Service as rare plants were investigated in this region. The plants above the third degree among the floristic regional indicator plants designated by the Korean Ministry of Environment were 10 taxa. In addition, 33 taxa of naturalized and 73 taxa of cultivated plants were recorded.

New insights on the evolution of Leafy cotyledon1 (LEC1) type genes in vascular plants.

Science.gov (United States)

Cagliari, Alexandro; Turchetto-Zolet, Andreia Carina; Korbes, Ana Paula; Maraschin, Felipe Dos Santos; Margis, Rogerio; Margis-Pinheiro, Marcia

2014-01-01

NF-Y is a conserved oligomeric transcription factor found in all eukaryotes. In plants, this regulator evolved with a broad diversification of the genes coding for its three subunits (NF-YA, NF-YB and NF-YC). The NF-YB members can be divided into Leafy Cotyledon1 (LEC1) and non-LEC1 types. Here we presented a comparative genomic study using phylogenetic analyses to validate an evolutionary model for the origin of LEC-type genes in plants and their emergence from non-LEC1-type genes. We identified LEC1-type members in all vascular plant genomes, but not in amoebozoa, algae, fungi, metazoa and non-vascular plant representatives, which present exclusively non-LEC1-type genes as constituents of their NF-YB subunits. The non-synonymous to synonymous nucleotide substitution rates (Ka/Ks) between LEC1 and non-LEC1-type genes indicate the presence of positive selection acting on LEC1-type members to the fixation of LEC1-specific amino acid residues. The phylogenetic analyses demonstrated that plant LEC1-type genes are evolutionary divergent from the non-LEC1-type genes of plants, fungi, amoebozoa, algae and animals. Our results point to a scenario in which LEC1-type genes have originated in vascular plants after gene expansion in plants. We suggest that processes of neofunctionalization and/or subfunctionalization were responsible for the emergence of a versatile role for LEC1-type genes in vascular plants, especially in seed plants. LEC1-type genes besides being phylogenetic divergent also present different expression profile when compared with non-LEC1-type genes. Altogether, our data provide new insights about the LEC1 and non-LEC1 evolutionary relationship during the vascular plant evolution. Copyright © 2014 Elsevier Inc. All rights reserved.

Applicability of MIEX(®)DOC process for organics removal from NOM laden water.

Science.gov (United States)

Karpinska, Anna M; Boaventura, Rui A R; Vilar, Vítor J P; Bilyk, Andrzej; Molczan, Marek

2013-06-01

The aim of this study was to evaluate applicability of ion exchange process for organics removal from Douro River surface water at the intake of Lever water treatment plant using magnetized ion exchange resin MIEX®. Qualitative analysis of the natural organic matter present in the surface water and prediction of its amenability to removal in conventional coagulation process were assessed. Results obtained in MIEX®DOC process kinetic batch experiments allowed determination of ion exchange efficiency in dissolved organic carbon (DOC), UV absorbing organics, and true color removal. The data were compared with the efficiencies of the conventional unit processes for organics removal at Lever WTP. MIEX®DOC process revealed to be more efficient in DOC removal than conventional treatment achieving the efficiencies in the range of 61-91 %, lowering disinfection by-products formation potential of the water. DOC removal efficiency at Lever WTP depends largely on the raw water quality and ranges from 28 % for water of moderated quality to 89 % of significantly deteriorated quality. In this work, MIEX®DOC process was also used as a reference method for the determination of contribution of anionic fraction to dissolved organic matter and selectivity of the unit processes at Lever WTP for its removal.

The two faces of DOC.

Science.gov (United States)

Wood, Chris M; Al-Reasi, H A; Smith, D Scott

2011-10-01

Dissolved organic carbon (DOC), through its ability to complex metals and thereby reduce their bioavailability, plays a major role in ameliorating metal toxicity in natural waters. Indeed DOC is a key variable in the Biotic Ligand Model (BLM) for predicting metal toxicity on a site-specific basis. However, recent evidence indicates that all DOCs are not alike, but rather heterogeneous in their ability to protect organisms against metal toxicity, at least in fresh water. The degree of protection appears to correlate with optical properties, such that dark, aromatic-rich compounds of allochthonous origin, with greater humic acid content, are more effective in this regard, particularly against Cu, Ag, and Pb toxicity. The specific absorption coefficient of the DOC in the 300-350nm range (SAC(300-350)) has proven to be a simple and effective index of this protective ability. PARAFAC, a multivariate statistical technique for analysis of excitation-emission fluorescence spectroscopy data, also holds promise for quantifying the humic-like and fulvic-like fluorophores, which tend to be positively and negatively correlated with protective ability, respectively. However, what has been largely missing in the toxicological realm is any appreciation that DOC may also affect the physiology of target organisms, such that part of the protection may occur by a mechanism other than metal complexation. Recently published evidence demonstrates that DOC has effects on Na(+) transport, diffusive permeability, and electrical properties of the gills in fish and crustaceans in a manner which will promote Na(+) homeostasis. These actions could thereby protect against metal toxicity by physiological mechanisms. Future research should investigate potential direct interactions of DOC molecules with the branchial epithelium. Incorporation of optical properties of DOC could be used to improve the predictive capabilities of the BLM. 2011 Elsevier B.V. All rights reserved.

Stomatal Blue Light Response Is Present in Early Vascular Plants.

Science.gov (United States)

Doi, Michio; Kitagawa, Yuki; Shimazaki, Ken-ichiro

2015-10-01

Light is a major environmental factor required for stomatal opening. Blue light (BL) induces stomatal opening in higher plants as a signal under the photosynthetic active radiation. The stomatal BL response is not present in the fern species of Polypodiopsida. The acquisition of a stomatal BL response might provide competitive advantages in both the uptake of CO2 and prevention of water loss with the ability to rapidly open and close stomata. We surveyed the stomatal opening in response to strong red light (RL) and weak BL under the RL with gas exchange technique in a diverse selection of plant species from euphyllophytes, including spermatophytes and monilophytes, to lycophytes. We showed the presence of RL-induced stomatal opening in most of these species and found that the BL responses operated in all euphyllophytes except Polypodiopsida. We also confirmed that the stomatal opening in lycophytes, the early vascular plants, is driven by plasma membrane proton-translocating adenosine triphosphatase and K(+) accumulation in guard cells, which is the same mechanism operating in stomata of angiosperms. These results suggest that the early vascular plants respond to both RL and BL and actively regulate stomatal aperture. We also found three plant species that absolutely require BL for both stomatal opening and photosynthetic CO2 fixation, including a gymnosperm, C. revoluta, and the ferns Equisetum hyemale and Psilotum nudum. © 2015 American Society of Plant Biologists. All Rights Reserved.

The Root-Associated Microbial Community of the World’s Highest Growing Vascular Plants

Czech Academy of Sciences Publication Activity Database

Angel, R.; Conrad, R.; Dvorský, Miroslav; Kopecký, Martin; Kotilínek, M.; Hiiesalu, Inga; Schweingruber, F. H.; Doležal, Jiří

2016-01-01

Roč. 72, č. 2 (2016), s. 394-406 ISSN 0095-3628 Institutional support: RVO:67985939 Keywords : vascular plants * upward migration * subnival soil * plant-associated bacteria Subject RIV: EF - Botanics Impact factor: 3.630, year: 2016

Distributions of vascular plants in the Czech Republic. Part 3

Czech Academy of Sciences Publication Activity Database

Kaplan, Zdeněk; Danihelka, Jiří; Lepší, M.; Lepší, P.; Ekrt, L.; Chrtek, Jindřich; Kocián, J.; Prančl, Jan; Kobrlová, L.; Hroneš, M.; Šulc, Václav

2016-01-01

Roč. 88, č. 4 (2016), s. 459-544 ISSN 0032-7786 R&D Projects: GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : distribution * vascular plants * Czech Republic Subject RIV: EF - Botanics Impact factor: 3.000, year: 2016

Database of Vascular Plants of Canada (VASCAN): a community contributed taxonomic checklist of all vascular plants of Canada, Saint Pierre and Miquelon, and Greenland.

Science.gov (United States)

Desmet, Peter; Brouillet, Luc

2013-01-01

The Database of Vascular Plants of Canada or VASCAN (http://data.canadensys.net/vascan) is a comprehensive and curated checklist of all vascular plants reported in Canada, Greenland (Denmark), and Saint Pierre and Miquelon (France). VASCAN was developed at the Université de Montréal Biodiversity Centre and is maintained by a group of editors and contributors. For every core taxon in the checklist (species, subspecies, or variety), VASCAN provides the accepted scientific name, the accepted French and English vernacular names, and their synonyms/alternatives in Canada, as well as the distribution status (native, introduced, ephemeral, excluded, extirpated, doubtful or absent) of the plant for each province or territory, and the habit (tree, shrub, herb and/or vine) of the plant in Canada. For reported hybrids (nothotaxa or hybrid formulas) VASCAN also provides the hybrid parents, except if the parents of the hybrid do not occur in Canada. All taxa are linked to a classification. VASCAN refers to a source for all name, classification and distribution information. All data have been released to the public domain under a CC0 waiver and are available through Canadensys and the Global Biodiversity Information Facility (GBIF). VASCAN is a service to the scientific community and the general public, including administrations, companies, and non-governmental organizations.

Patterns of species diversity and phylogenetic structure of vascular plants on the Qinghai-Tibetan Plateau.

Science.gov (United States)

Yan, Yujing; Yang, Xian; Tang, Zhiyao

2013-11-01

Large-scale patterns of species richness and the underlying mechanisms regulating these patterns have long been the central issues in biogeography and macroecology. Phylogenetic community structure is a result of combined effects of contemporary ecological interactions, environmental filtering, and evolutionary history, and it links community ecology with biogeography and trait evolution. The Qinghai-Tibetan Plateau provides a good opportunity to test the influence of contemporary climate on shaping species richness because of its unique geological history, cold climate, and high biodiversity. In this study, based on high-resolution distributions of ˜9000 vascular plant species, we explored how species richness and phylogenetic structure of vascular plants correlate with climates on the highest (and species rich) plateau on the Earth. The results showed that most of the vascular plants were distributed on the eastern part of the plateau; there was a strong association between species richness and climate, even after the effects of habitat heterogeneity were controlled. However, the responses of richness to climate remarkably depended on life-forms. Richness of woody plants showed stronger climatic associations than that of herbaceous plants; energy and water availability together regulated richness pattern of woody plants; whereas water availability predominantly regulated richness pattern of herbaceous plants. The phylogenetic structure of vascular species clustered in most areas of the plateau, suggesting that rapid speciation and environment filtering dominated the assembly of communities on the plateau. We further propose that biodiversity conservation in this area should better take into account ecological features for different life-forms and phylogenetic lineages.

Sphagnum modifies climate-change impacts on subarctic vascular bog plants.

NARCIS (Netherlands)

Dorrepaal, E.; Aerts, R.; Cornelissen, J.H.C.; van Logtestijn, R.S.P; Callaghan, T.V.

2006-01-01

1. Vascular plant growth forms in northern peatlands differ in their strategies to cope with the harsh climate, low nutrient availability and progressively increasing height of the Sphagnum carpet in which they grow. Climate change may therefore affect growth forms differentially, both directly and

The Heavy Links between Geological Events and Vascular Plants Evolution: A Brief Outline.

Science.gov (United States)

Piombino, Aldo

2016-01-01

Since the rise of photosynthesis, life has influenced terrestrial atmosphere, particularly the O2 and the CO2 content (the latter being originally more than 95%), changing the chemistry of waters, atmosphere, and soils. Billions of years after, a far offspring of these first unicellular forms conquered emerging lands, not only completely changing landscape, but also modifying geological cycles of deposition and erosion, many chemical and physical characteristics of soils and fresh waters, and, more, the cycle of various elements. So, there are no doubts that vascular plants modified geology; but it is true that also geology has affected (and, more, has driven) plant evolution. New software, PyRate, has determined vascular plant origin and diversification through a Bayesian analysis of fossil record from Silurian to today, particularly observing their origination and extinction rate. A comparison between PyRate data and geological history suggests that geological events massively influenced plant evolution and that also the rise of nonflowering seed plants and the fast diffusion of flowering plants can be explained, almost partly, with the environmental condition changes induced by geological phenomena.

Vascular Plants of the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Sackschewsky, Michael R.; Downs, Janelle L.

2001-09-28

This report provides an updated listing of the vascular plants present on and near the U.S. Department of Energy Hanford Site. This document is an update of a listing of plants prepared by Sackschewdky et al. in 1992. Since that time there has been a significant increase in the botanical knowledge of the Hanford Site. The present listing is based on an examination of herbarium collections held at PNNL, at WSU-Tri Cities, WSU-Pullman, Bringham Young University, and The University of Washington, and on examination of ecological literature derived from the Hanford and Benton county areas over the last 100 years. Based on the most recent analysis, there are approximately 725 different plant species that have been documented on or around the Hanford Site. This represents an approximate 20% increase in the number of species reported within Sackschewsky et al. (1992). This listing directly supports DOE and contractor efforts to assess the potential impacts of Hanford Site operations on the biological environment, including impacts to rare habitats and to species listed as endangered or\\ threatened. This document includes a listing of plants currently listed as endangered, threatened, or otherwise of concern to the Washington Natural Heritage Program or the U.S. Fish and Wildlife Service, as well as those that are currently listed as noxious weeds by the State of Washington. Also provided is an overview of how plants on the Hanford Site can be used by people. This information may be useful in developing risk assessment models, and as supporting information for clean-up level and remediation decisions.

Global transcriptome analysis reveals extensive gene remodeling, alternative splicing and differential transcription profiles in non-seed vascular plant Selaginella moellendorffii.

Science.gov (United States)

Zhu, Yan; Chen, Longxian; Zhang, Chengjun; Hao, Pei; Jing, Xinyun; Li, Xuan

2017-01-25

Selaginella moellendorffii, a lycophyte, is a model plant to study the early evolution and development of vascular plants. As the first and only sequenced lycophyte to date, the genome of S. moellendorffii revealed many conserved genes and pathways, as well as specialized genes different from flowering plants. Despite the progress made, little is known about long noncoding RNAs (lncRNA) and the alternative splicing (AS) of coding genes in S. moellendorffii. Its coding gene models have not been fully validated with transcriptome data. Furthermore, it remains important to understand whether the regulatory mechanisms similar to flowering plants are used, and how they operate in a non-seed primitive vascular plant. RNA-sequencing (RNA-seq) was performed for three S. moellendorffii tissues, root, stem, and leaf, by constructing strand-specific RNA-seq libraries from RNA purified using RiboMinus isolation protocol. A total of 176 million reads (44 Gbp) were obtained from three tissue types, and were mapped to S. moellendorffii genome. By comparing with 22,285 existing gene models of S. moellendorffii, we identified 7930 high-confidence novel coding genes (a 35.6% increase), and for the first time reported 4422 lncRNAs in a lycophyte. Further, we refined 2461 (11.0%) of existing gene models, and identified 11,030 AS events (for 5957 coding genes) revealed for the first time for lycophytes. Tissue-specific gene expression with functional implication was analyzed, and 1031, 554, and 269 coding genes, and 174, 39, and 17 lncRNAs were identified in root, stem, and leaf tissues, respectively. The expression of critical genes for vascular development stages, i.e. formation of provascular cells, xylem specification and differentiation, and phloem specification and differentiation, was compared in S. moellendorffii tissues, indicating a less complex regulatory mechanism in lycophytes than in flowering plants. The results were further strengthened by the evolutionary trend of

Contrasting species-environment relationships in communities of testate amoebae, bryophytes and vascular plants along the fen-bog gradient.

Science.gov (United States)

Lamentowicz, Mariusz; Lamentowicz, Lukasz; van der Knaap, Willem O; Gabka, Maciej; Mitchell, Edward A D

2010-04-01

We studied the vegetation, testate amoebae and abiotic variables (depth of the water table, pH, electrical conductivity, Ca and Mg concentrations of water extracted from mosses) along the bog to extremely rich fen gradient in sub-alpine peatlands of the Upper Engadine (Swiss Alps). Testate amoeba diversity was correlated to that of mosses but not of vascular plants. Diversity peaked in rich fen for testate amoebae and in extremely rich fen for mosses, while for testate amoebae and mosses it was lowest in bog but for vascular plants in extremely rich fen. Multiple factor and redundancy analyses (RDA) revealed a stronger correlation of testate amoebae than of vegetation to water table and hydrochemical variables and relatively strong correlation between testate amoeba and moss community data. In RDA, hydrochemical variables explained a higher proportion of the testate amoeba and moss data than water table depth. Abiotic variables explained a higher percentage of the species data for testate amoebae (30.3% or 19.5% for binary data) than for mosses (13.4%) and vascular plants (10%). These results show that (1) vascular plant, moss and testate amoeba communities respond differently to ecological gradients in peatlands and (2) testate amoebae are more strongly related than vascular plants to the abiotic factors at the mire surface. These differences are related to vertical trophic gradients and associated niche differentiation.

Distribution and functional traits of charophytes and vascular plants

DEFF Research Database (Denmark)

Båstrup-Spohr, Lars

rare species are specialists in particular environments, while the abundant species have traits such as broad salinity tolerance, tall shoots, vegetative reproduction and variable life form. Vascular plants, in contrast to charophytes, occupy the entire gradient from submerged to drained conditions......A large variety of plant species of very different evolutionary origin are found within and along the margins of aquatic ecosystems. These species have very different adaptations depending on the particular environmental condition under which they grow. This thesis examines the role...... of these adaptations or functional traits for the distribution on large scales and along specific environmental gradients. Characean algae (charophytes) are an ancient group of aquatic plants found in most aquatic ecosystems. I confirmed that they have declined markedly during the 20th century, most likely...

Structural evolution of the 4/1 genes and proteins in non-vascular and lower vascular plants.

Science.gov (United States)

Morozov, Sergey Y; Milyutina, Irina A; Bobrova, Vera K; Ryazantsev, Dmitry Y; Erokhina, Tatiana N; Zavriev, Sergey K; Agranovsky, Alexey A; Solovyev, Andrey G; Troitsky, Alexey V

2015-12-01

The 4/1 protein of unknown function is encoded by a single-copy gene in most higher plants. The 4/1 protein of Nicotiana tabacum (Nt-4/1 protein) has been shown to be alpha-helical and predominantly expressed in conductive tissues. Here, we report the analysis of 4/1 genes and the encoded proteins of lower land plants. Sequences of a number of 4/1 genes from liverworts, lycophytes, ferns and gymnosperms were determined and analyzed together with sequences available in databases. Most of the vascular plants were found to encode Magnoliophyta-like 4/1 proteins exhibiting previously described gene structure and protein properties. Identification of the 4/1-like proteins in hornworts, liverworts and charophyte algae (sister lineage to all land plants) but not in mosses suggests that 4/1 proteins are likely important for plant development but not required for a primary metabolic function of plant cell. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Vascular Plant and Vertebrate Inventory of Chiricahua National Monument

Science.gov (United States)

Powell, Brian F.; Schmidt, Cecilia A.; Halvorson, William L.; Anning, Pamela

2009-01-01

This report summarizes the results of the first comprehensive inventory of vascular plants and vertebrates at Chiricahua National Monument (NM) in Arizona. This project was part of a larger effort to inventory vascular plants and vertebrates in eight National Park Service units in the Sonoran Desert Network of parks in Arizona and New Mexico. In 2002, 2003, and 2004 we surveyed for plants and vertebrates (amphibians, reptiles, birds, and mammals) at Chiricahua NM to document the presence of species within the boundaries of the monument. Because we used repeatable study designs and standardized field methods, these inventories can serve as the first step in a biological monitoring program for the monument. This report is also the first summary of previous research from the monument and therefore it provides an important overview of survey efforts to date. We used data from our inventory and previous research to compile complete species lists for the monument and to assess inventory completeness. We recorded a total of 424 species, including 37 not previously found at the monument (Table 1). We found 10 species of non-native plants and one non-native mammal. Most non-native plants were found along the western boundary of the monument. Based on a review of our inventory and past research at the monument, there have been a total of 1,137 species of plants and vertebrates found at the monument. We believe the inventories of vascular plants and vertebrates are nearly complete and that the monument has one of the most complete inventories of any unit in the Sonoran Desert Network. The mammal community at the monument had the highest species richness (69 species) and the amphibian and reptile community was among the lowest species richness (33 species) of any park in the Sonoran Desert Network. Species richness of the plant and bird communities was intermediate. Among the important determinants of species richness for all groups is the geographic location of the monument

Interactions between soil phototrophs and vascular plants in Himalayan cold deserts

Czech Academy of Sciences Publication Activity Database

Řeháková, Klára; Čapková, Kateřina; Dvorský, Miroslav; Kopecký, Martin; Altman, Jan; Šmilauer, P.; Doležal, Jiří

2017-01-01

Roč. 115, dec 2017 (2017), s. 568-578 ISSN 0038-0717 R&D Projects: GA ČR GA13-13368S Institutional support: RVO:67985939 Keywords : microbial communities * vascular plants * interactions Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 4.857, year: 2016

Origins of native vascular plants of Antarctica: comments from a historical phytogeography viewpoint.

Science.gov (United States)

Mosyakin, S L; Bezusko, L G; Mosyakin, A S

2007-01-01

The article provides an overview of the problem of origin of the only native vascular plants of Antarctica, Deschampsia antartica (Poaceae) and Colobanthus quitensis (Caryophyllaceae), from the viewpoint of modern historical phytogeography and related fields of science. Some authors suggested the Tertiary relict status of these plants in Antarctica, while others favour their recent Holocene immigration. Direct data (fossil or molecular genetic ones) for solving this controversy is still lacking. However, there is no convincing evidence supporting the Tertiary relict status of these plants in Antarctica. Most probably D. antarctica and C. quitensis migrated to Antarctica in the Holocene or Late Pleistocene (last interglacial?) through bird-aided long-distance dispersal. It should be critically tested by (1) appropriate methods of molecular phylogeography, (2) molecular clock methods, if feasible, (3) direct paleobotanical studies, (4) paleoclimatic reconstructions, and (5) comparison with cases of taxa with similar distribution/dispersal patterns. The problem of the origin of Antarctic vascular plants is a perfect model for integration of modern methods of molecular phylogeography and phylogenetics, population biology, paleobiology and paleogeography for solving a long-standing enigma of historical plant geography and evolution.

Radiocontamination patterns of vascular plants in a forest ecosystem

International Nuclear Information System (INIS)

Nimis, P.L.; Bolognini, G.; Giovani, C.

1994-01-01

This study is based on measurements of radiocesium and potassium-40 in leaves, stems and roots of 48 vascular plants in a natural beech forest in the Carnic Alps (NE Italy). The data have been submitted to numerical classification, and the main results are: (a) radiocontamination patterns and ecology of the species are well related, (b) three main groups of species with different radiocontamination can be distinguished: plants in clearings, forest plants rooting in the organic soil layer, forest plants rooting in the mineral layer; (c) radiocesium tends to be retained in the roots, especially in plants in the clearings; (d) Pteridophytes, contrary to all other plants, are able to discriminate between cesium and potassium at leaf level; (e) for all other species, cesium and potassium, once taken up by the plant, exhibit a similar behaviour; (f) total contamination by radiocesium is related to the depth of the root systems, and to the unequal distribution of radiocesium in the soil profile. Species-specific mechanisms of differential absorption are not evident in the investigated forest; the radiocontamination of plants can be easily explained in ecological terms. Radiocontamination on a water basis (Bq/l) is suggested as being much more appropriate for solving certain radioecological problems

Local above-ground persistence of vascular plants : Life-history trade-offs and environmental constraints

NARCIS (Netherlands)

Ozinga, Wim A.; Hennekens, Stephan M.; Schaminee, Joop H. J.; Smits, Nina A. C.; Bekker, Renee M.; Roemermann, Christine; Klimes, Leos; Bakker, Jan P.; van Groenendael, Jan M.

Questions: 1. Which plant traits and habitat characteristics best explain local above-ground persistence of vascular plant species and 2. Is there a trade-off between local above-ground persistence and the ability for seed dispersal and below-ground persistence in the soil seed bank? Locations: 845

Microbial community dynamics and transformation of vascular plant detritus in two wetland ecosystems

International Nuclear Information System (INIS)

Moran, M.A.

1987-01-01

The microbial ecology of two wetland ecosystems in southeastern Georgia, USA, was studied with respect to microbial community dynamics and microbially-mediated transformations of vascular plant detritus. In the Okefenokee Swamp, biomass of microorganisms in the water column and sediments was generally lower in winter months and higher during spring and summer. Biomass and activity (measured as 14 C-lignocellulose mineralization) differed significantly among five habitats within the Okefenokee, and also among locations within each habitat. Significant heterogeneity in the structure of Okefenokee microbial communities was found at scales from 30 cm to 150 m. In field and laboratory studies of vascular plant decomposition in the Okefenokee and a salt marsh on Sapelo Island, the mathematical model which best describes decomposition kinetics is the decaying coefficient model

Investigating Forest Harvest Effects on DOC Concentration and Quality: An In Situ, High Resolution Approach to Quantifying DOC Export Dynamics

Science.gov (United States)

Jollymore, A. J.; Johnson, M. S.; Hawthorne, I.

2013-12-01

Justification: Forest harvest effects on water quality can signal alterations in hydrologic and ecologic processes incurred as a result of forest harvest activities. Organic matter (OM), specifically dissolved organic carbon (DOC), plays a number of important roles mediating UV-light penetration, redox reactivity and microbial activity within aquatic ecosystems. Quantification of DOC is typically pursued via grab sampling followed by chemical or spectrophotometric analysis, limiting the temporal resolution obtained as well as the accuracy of export calculations. The advent of field-deployable sensors capable of measuring DOC concentration and certain quality characteristics in situ provides the ability to observe dynamics at temporal scales necessary for accurate calculation of DOC flux, as well as the observation of dynamic changes in DOC quality on timescales impossible to observe through grab sampling. Methods: This study utilizes a field deployable UV-Vis spectrophotometer (spectro::lyzer, s::can, Austria) to investigate how forest harvest affects DOC export. The sensor was installed at an existing hydrologic monitoring site at the outlet of a headwater stream draining a small (91 hectare) second growth Douglasfir-dominated catchment near Campbell River on Vancouver Island, British Columbia. Measurement began late in 2009, prior to forest harvest and associated activities such as road building (which commenced in October 2010 and ended in early 2011), and continues to present. During this time - encompassing the pre, during and post-harvest conditions - the absorbance spectrum of stream water from 200 to 750 nm was measured. DOC concentration and spectroscopic indices related to DOC quality (including SUVA, which relates to the concentration of aromatic carbon, and spectral slope) were subsequently calculated for each spectra obtained at 30-minute intervals. Results and conclusions: High frequency measurements of DOC show that overall export of OM increased in

New Chorological Data for Rare Vascular Plants from Romania

Directory of Open Access Journals (Sweden)

Anastasiu Paulina

2015-11-01

Full Text Available New chorological data about seven rare vascular plant taxa are reported in the present paper: Conringia austriaca, Jurinea multiflora, Linaria arvensis, Nonea pallens, Ophrys apifera, Ophrys scolopax subsp. cornuta, Saponaria officinalis. For Linaria arvensis, previously considered doubtful in the absence of the herbarium material, we confirm its presence in Romania. The report of Nonea pallens is the first for Dobrogea, while the report of Jurinea multiflora is the first for Muntenia region of Romania.

Interferences between Sphagnum and vascular plants: effects on plant community structure and peat formation

OpenAIRE

Malmer, Nils; Albinsson, C; Svensson, B M; Wallén, Bo

2003-01-01

The interference between vascular plants and peat mosses with respect to nitrogen and phosphorus was studied in a fertilization experiment and with respect to competition for light in a removal experiment in poor fens with either soligenous or topogenous hydrology using Narthecium ossifragum (L.) Huds. and three species of Sphagnum sect. Sphagnum as targets. Adding fertilizer either on the moss surface or below it confirmed the hypotheses of an asymmetric competition for nutrients, viz. that ...

76 FR 9210 - Draft DOC National Aquaculture Policy

Science.gov (United States)

2011-02-16

... DEPARTMENT OF COMMERCE Draft DOC National Aquaculture Policy AGENCY: Commerce. ACTION: Notice of availability of draft aquaculture policy; request for comments. SUMMARY: The Department of Commerce (DOC) is... United States. The intent of the policy is to guide DOC's actions and decisions on aquaculture and to...

CDOM-DOC relationship in contrasted coastal waters: implication for DOC retrieval from ocean color remote sensing observation.

Science.gov (United States)

Vantrepotte, Vincent; Danhiez, François-Pierre; Loisel, Hubert; Ouillon, Sylvain; Mériaux, Xavier; Cauvin, Arnaud; Dessailly, David

2015-01-12

Increasing our knowledge on dissolved organic carbon (DOC) spatio-temporal distribution in the coastal ocean represents a crucial challenge for better understanding the role of these ecosystems in the global oceanic carbon cycle. The assessment of DOC concentration from the absorption properties of the colored part of the dissolved organic matter (a(cdom)) was investigated from an extensive data set covering a variety of coastal environments. Our results confirmed that variation in the a(cdom)(412) to DOC ratio (a*(cdom)(412)) can be depicted from the CDOM spectral slope in the UV domain (S(275-295)). They also evidenced that regional first order variation in both a*(cdom)(412) and S(275-295) are highly correlated to variation in a(cdom)(412). From these observations, generalized relationships for estimating a*(cdom)(412) from S(275-295) or a(cdom)(412) were parameterized from our development sites (N = 158; English Channel, French Guiana, Hai Phong Bay) and tested against an independent data set covering others coastal regions (N = 223; French Polynesia, Rhone River estuary, Gulf of Maine, Chesapeake Bay, Southern Middle Atlantic Bight) demonstrating the possibility to derive DOC estimates from in situ CDOM optical properties with an average accuracy of ~16% over very contrasted coastal environments (with DOC ranging from 50 to 250 µmol.L(-1)). The applicability of these generalized approaches was evaluated in the context of ocean color remote sensing observation emphasizing the limits of S(275-295)-based formulations and the potential for a(cdom)-based approaches to represent a compelling alternative for assessing synoptic DOC distribution.

Comparative Genomics Yields Insights into Niche Adaptation of Plant Vascular Wilt Pathogens

NARCIS (Netherlands)

Klosterman, S.J.; Subbarao, K.V.; Kang, S.; Veronese, P.; Gold, S.E.; Thomma, B.P.H.J.; Chen, Z.J.; Henrissat, B.; Lee, Y.H.; Park, J.; Garcia-Pedrajas, M.D.; Barbara, D.J.; Anchieta, A.; Jonge, de R.; Santhanam, P.; Maruthachalam, K.; Atallah, Z.; Amyotte, S.G.; Paz, Z.; Inderbitzin, P.; Hayes, R.J.; Heiman, D.I.; Young, S.; Zeng, Q.; Engels, R.; Galagan, J.; Cuomo, C.; Dobinson, K.F.; Ma, L.J.

2011-01-01

The vascular wilt fungi Verticillium dahliae and V. albo-atrum infect over 200 plant species, causing billions of dollars in annual crop losses. The characteristic wilt symptoms are a result of colonization and proliferation of the pathogens in the xylem vessels, which undergo fluctuations in

Decreasing soil water Ca2+ reduces DOC adsorption in mineral soils: implications for long-term DOC trends in an upland forested catchment in southern Ontario, Canada.

Science.gov (United States)

Kerr, Jason Grainger; Eimers, M Catherine

2012-06-15

Positive trends in dissolved organic carbon (DOC) concentration have been observed in surface waters throughout North America and northern Europe. Although adsorption in mineral soils is an important driver of DOC in upland streams, little is known about the potential for changes in DOC adsorption to contribute to these trends. We hypothesized that long-term declines in soil water Ca(2+) levels, in response to declining acid deposition, might influence DOC adsorption and that this could contribute to long-term DOC trends in an upland forested catchment in south-central Ontario, Canada. Between 1987 and 2009, DOC concentrations increased significantly (pDOC concentration (DOC(np)), which is a measure of the soil water DOC concentration at equilibrium with the soil, ranged from 1.27 to 3.75 mg L(-1) in B horizon soils. This was similar to the mean DOC concentrations of B horizon soil water (2.04-6.30 mg L(-1)) and stream water (2.20 mg L(-1)), indicating that soil and stream water DOC concentrations are controlled by equilibrium processes at the soil-water interface. Adsorption experiments using variable Ca(2+) concentrations demonstrated that as Ca(2+) decreased the DOC(np) increased (1.96 to 4.74 mg L(-1)), which was consistent with the observed negative correlation between DOC and Ca(2+) in B horizon soil water (pDOC adsorption (p>0.05), indicating that changes in DOC adsorption might be related to cation bridging. We conclude that declines in soil water Ca(2+) concentration can contribute to increasing DOC trends in upland streams by reducing DOC adsorption in mineral soils. Copyright © 2012 Elsevier B.V. All rights reserved.

Earth System Documentation (ES-DOC) Preparation for CMIP6

Science.gov (United States)

Denvil, S.; Murphy, S.; Greenslade, M. A.; Lawrence, B.; Guilyardi, E.; Pascoe, C.; Treshanksy, A.; Elkington, M.; Hibling, E.; Hassell, D.

2015-12-01

During the course of 2015 the Earth System Documentation (ES-DOC) project began its preparations for CMIP6 (Coupled Model Inter-comparison Project 6) by further extending the ES-DOC tooling ecosystem in support of Earth System Model (ESM) documentation creation, search, viewing & comparison. The ES-DOC online questionnaire, the ES-DOC desktop notebook, and the ES-DOC python toolkit will serve as multiple complementary pathways to generating CMIP6 documentation. It is envisaged that institutes will leverage these tools at different points of the CMIP6 lifecycle. Institutes will be particularly interested to know that the documentation burden will be either streamlined or completely automated.As all the tools are tightly integrated with the ES-DOC web-service, institutes can be confident that the latency between documentation creation & publishing will be reduced to a minimum. Published documents will be viewable with the online ES-DOC Viewer (accessible via citable URL's). Model inter-comparison scenarios will be supported using the ES-DOC online Comparator tool. The Comparator is being extended to:• Support comparison of both Model descriptions & Simulation runs;• Greatly streamline the effort involved in compiling official tables.The entire ES-DOC ecosystem is open source and built upon open standards such as the Common Information Model (CIM) (versions 1 and 2).

Dataset of herbarium specimens of threatened vascular plants in Catalonia.

Science.gov (United States)

Nualart, Neus; Ibáñez, Neus; Luque, Pere; Pedrol, Joan; Vilar, Lluís; Guàrdia, Roser

2017-01-01

This data paper describes a specimens' dataset of the Catalonian threatened vascular plants conserved in five public Catalonian herbaria (BC, BCN, HGI, HBIL and MTTE). Catalonia is an administrative region of Spain that includes large autochthon plants diversity and 199 taxa with IUCN threatened categories (EX, EW, RE, CR, EN and VU). This dataset includes 1,618 records collected from 17 th century to nowadays. For each specimen, the species name, locality indication, collection date, collector, ecology and revision label are recorded. More than 94% of the taxa are represented in the herbaria, which evidence the paper of the botanical collections as an essential source of occurrence data.

Disjunct populations of European vascular plant species keep the same climatic niches

DEFF Research Database (Denmark)

Wasof, Safaa; Lenoir, Jonathan; Aarrestad, Per Arild

2015-01-01

separated for thousands of years. Location: European Alps and Fennoscandia. Methods: Of the studied pool of 888 terrestrial vascular plant species occurring in both the Alps and Fennoscandia, we used two complementary approaches to test and quantify climatic-niche shifts for 31 species having strictly......Aim: Previous research on how climatic niches vary across species ranges has focused on a limited number of species, mostly invasive, and has not, to date, been very conclusive. Here we assess the degree of niche conservatism between distant populations of native alpine plant species that have been...... to be largely valid for arctic-alpine plants....

Method for treating wastewater using microorganisms and vascular aquatic plants

Science.gov (United States)

Wolverton, B. C. (Inventor)

1983-01-01

A method for treating wastewater compresses subjecting the wastewater to an anaerobic setting step for at least 6 hours and passing the liquid effluent from the anaerobic settling step through a filter cell in an upflow manner. There the effluent is subjected first to the action of anaerobic and facultative microorganisms, and then to the action of aerobic microorganisms and the roots of at least one vascular aquatic plant.

Function analysis of 5'-UTR of the cellulosomal xyl-doc cluster in Clostridium papyrosolvens.

Science.gov (United States)

Zou, Xia; Ren, Zhenxing; Wang, Na; Cheng, Yin; Jiang, Yuanyuan; Wang, Yan; Xu, Chenggang

2018-01-01

Anaerobic, mesophilic, and cellulolytic Clostridium papyrosolvens produces an efficient cellulolytic extracellular complex named cellulosome that hydrolyzes plant cell wall polysaccharides into simple sugars. Its genome harbors two long cellulosomal clusters: cip - cel operon encoding major cellulosome components (including scaffolding) and xyl - doc gene cluster encoding hemicellulases. Compared with works on cip - cel operon, there are much fewer studies on xyl - doc mainly due to its rare location in cellulolytic clostridia. Sequence analysis of xyl - doc revealed that it harbors a 5' untranslated region (5'-UTR) which potentially plays a role in the regulation of downstream gene expression. Here, we analyzed the function of 5'-UTR of xyl - doc cluster in C. papyrosolvens in vivo via transformation technology developed in this study. In this study, we firstly developed an electrotransformation method for C. papyrosolvens DSM 2782 before the analysis of 5'-UTR of xyl - doc cluster. In the optimized condition, a field with an intensity of 7.5-9.0 kV/cm was applied to a cuvette (0.2 cm gap) containing a mixture of plasmid and late cell suspended in exponential phase to form a 5 ms pulse in a sucrose-containing buffer. Afterwards, the putative promoter and the 5'-UTR of xyl - doc cluster were determined by sequence alignment. It is indicated that xyl - doc possesses a long conservative 5'-UTR with a complex secondary structure encompassing at least two perfect stem-loops which are potential candidates for controlling the transcriptional termination. In the last step, we employed an oxygen-independent flavin-based fluorescent protein (FbFP) as a quantitative reporter to analyze promoter activity and 5'-UTR function in vivo. It revealed that 5'-UTR significantly blocked transcription of downstream genes, but corn stover can relieve its suppression. In the present study, our results demonstrated that 5'-UTR of the cellulosomal xyl - doc cluster blocks the

DOC-dynamics in a small headwater catchment as driven by redox fluctuations and hydrological flow paths – are DOC exports mediated by iron reduction/oxidation cycles?

Directory of Open Access Journals (Sweden)

K.-H. Knorr

2013-02-01

Full Text Available Dissolved organic carbon (DOC exports from many catchments in Europe and North-America are steadily increasing. Several studies have sought to explain this observation. As possible causes, a decrease in acid rain or sulfate deposition, concomitant reductions in ionic strength and increasing temperatures were identified. DOC often originates from riparian wetlands; but here, despite higher DOC concentrations, ionic strength in pore waters usually exceeds that in surface waters. In the catchment under study, DOC concentrations were synchronous with dissolved iron concentrations in pore and stream water. This study aims at testing the hypothesis that DOC exports are mediated by iron reduction/oxidation cycles. Following the observed hydrographs, δ¹⁸O of water and DOC fluorescence, the wetlands were identified as the main source of DOC. Antecedent biogeochemical conditions, i.e., water table levels in the wetlands, influenced the discharge patterns of nitrate, iron and DOC during an event. The correlation of DOC with pH was positive in pore waters, but negative in surface waters; it was negative for DOC with sulfate in pore waters, but only weak in surface waters. Though, the positive correlation of DOC with iron was universal for pore and surface water. The decline of DOC and iron concentrations in transition from anoxic wetland pore water to oxic stream water suggests a flocculation of DOC with oxidising iron, leading to a drop in pH in the stream during high DOC fluxes. The pore water did not per se differ in pH. There is, thus, a need to consider processes more thoroughly of DOC mobilisation in wetlands when interpreting DOC exports from catchments. The coupling of DOC with iron fluxes suggested that increased DOC exports could at least, in part, be caused by increasing activities in iron reduction, possibly due to increases in temperature, increasing wetness of riparian wetlands, or by a shift from sulfate dominated to iron

Antioxidant and signal modulation properties of plant polyphenols in controlling vascular inflammation.

Science.gov (United States)

Kostyuk, Vladimir A; Potapovich, Alla I; Suhan, Tatyana O; de Luca, Chiara; Korkina, Liudmila G

2011-05-11

Oxidized low-density lipoproteins (oxLDL) play a critical role in the initiation of atherosclerosis through activation of inflammatory signaling. In the present work we investigated the role of antioxidant and signal modulation properties of plant polyphenols in controlling vascular inflammation. Significant decrease in intracellular NO level and superoxide overproduction was found in human umbilical vein endothelial cells (HUVEC) treated with oxLDL, but not with LDL. The redox imbalance was prevented by the addition of quercetin or resveratrol. Expression analysis of 14 genes associated with oxidative stress and inflammation revealed oxLDL-mediated up-regulation of genes specifically involved in leukocyte recruitment and adhesion. This up-regulation could be partially avoided by the addition of verbascoside or resveratrol, while treatment with quercetin resulted in a further increase in the expression of these genes. Lipopolysaccharide (LPS)-treated HUVEC were also used for the evaluation of anti-inflammatory potency of plant polyphenols. Significant differences between HUVEC treaded with oxLDL and LPS were found in both the expression pattern of inflammation-related genes and the effects of plant polyphenols on cellular responses. The present data indicate that plant polyphenols may affect vascular inflammation not only as antioxidants but also as modulators of inflammatory redox signaling pathways. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

An evaluation of organic substance fraction removal during ion exchange with Miex-DOC resin.

Science.gov (United States)

Wolska, Małgorzata

2015-07-01

In this study, the usefulness of Miex-DOC resin in eliminating organic substances and their fractions from water sources for drinking water was evaluated. The objects of study were samples from three surface water sources and one infiltration water source taken at water treatment plants before treatment in technical conditions. In particular, the effectiveness of removing biodegradable and non-biodegradable fractions as a function of resin dosages and water-resin contact times was evaluated. The ion exchange process with the Miex-DOC resin achieved a high effectiveness in removing aromatic non-biodegradable organic substances, and therefore a reduction in UV254 absorbance. The biodegradable fraction is much less susceptible to removal yet its removal effectiveness allows for a significant reduction in hazards connected with secondary microorganism development. The results of this study indicate the possibility of using ion exchange with the Miex-DOC resin for effective removal of disinfection by-product precursors.

Constraining Biomarkers of Dissolved Organic Matter Sourcing Using Microbial Incubations of Vascular Plant Leachates of the California landscape

Science.gov (United States)

Harfmann, J.; Hernes, P.; Chuang, C. Y.; Kaiser, K.; Spencer, R. G.; Guillemette, F.

2017-12-01

Source origin of dissolved organic matter (DOM) is crucial in determining reactivity, driving chemical and biological processing of carbon. DOM source biomarkers such as lignin (a vascular plant marker) and D-amino acids (bacterial markers) are well-established tools in tracing DOM origin and fate. The development of high-resolution mass spectrometry and optical studies has expanded our toolkit; yet despite these advances, our understanding of DOM sources and fate remains largely qualitative. Quantitative data on DOM pools and fluxes become increasingly necessary as we refine our comprehension of its composition. In this study, we aim to calibrate and quantify DOM source endmembers by performing microbial incubations of multiple vascular plant leachates, where total DOM is constrained by initial vascular plant input and microbial production. Derived endmembers may be applied to endmember mixing models to quantify DOM source contributions in aquatic systems.

Macroecological and macroevolutionary patterns of leaf herbivory across vascular plants.

Science.gov (United States)

Turcotte, Martin M; Davies, T Jonathan; Thomsen, Christina J M; Johnson, Marc T J

2014-07-22

The consumption of plants by animals underlies important evolutionary and ecological processes in nature. Arthropod herbivory evolved approximately 415 Ma and the ensuing coevolution between plants and herbivores is credited with generating much of the macroscopic diversity on the Earth. In contemporary ecosystems, herbivory provides the major conduit of energy from primary producers to consumers. Here, we show that when averaged across all major lineages of vascular plants, herbivores consume 5.3% of the leaf tissue produced annually by plants, whereas previous estimates are up to 3.8× higher. This result suggests that for many plant species, leaf herbivory may play a smaller role in energy and nutrient flow than currently thought. Comparative analyses of a diverse global sample of 1058 species across 2085 populations reveal that models of stabilizing selection best describe rates of leaf consumption, and that rates vary substantially within and among major plant lineages. A key determinant of this variation is plant growth form, where woody plant species experience 64% higher leaf herbivory than non-woody plants. Higher leaf herbivory in woody species supports a key prediction of the plant apparency theory. Our study provides insight into how a long history of coevolution has shaped the ecological and evolutionary relationships between plants and herbivores. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Vasorelaxation induced by common edible tropical plant extracts in isolated rat aorta and mesenteric vascular bed.

Science.gov (United States)

Runnie, I; Salleh, M N; Mohamed, S; Head, R J; Abeywardena, M Y

2004-06-01

In this study, the vasodilatory actions of nine edible tropical plant extracts were investigated. Ipomoea batatas (sweet potato leaf), Piper betle (betel leaf), Anacardium occidentale (cashew leaf), Gynandropsis gynandra (maman leaf), Carica papaya (papaya leaf), and Mentha arvensis (mint leaf) extracts exhibited more than 50% relaxing effect on aortic ring preparations, while Piper betle and Cymbopogon citratus (lemongrass stalk) showed comparable vasorelaxation on isolated perfused mesenteric artery preparation. The vascular effect on the aortic ring preparations were mainly endothelium-dependent, and mediated by nitric oxide (NO) as supported by the inhibition of action in the presence of N(omega)-nitro-L-arginine (NOLA), an nitric oxide synthase (NOS) inhibitor, or by the removal of endothelium. In contrast, vasodilatory actions in resistance vessels (perfused mesenteric vascular beds) appear to involve several biochemical mediators, including NO, prostanoids, and endothelium-dependent hyperpolarizing factors (EDHFs). Total phenolic contents and antioxidant capacities varied among different extracts and found to be independent of vascular relaxation effects. This study demonstrates that many edible plants common in Asian diets to possess potential health benefits, affording protection at the vascular endothelium level.

DocSaludMental en netvibes

OpenAIRE

Onís, Ricardo

2011-01-01

DocSaludMental es un escritorio virtual que, a partir de la plataforma netvibes, permite el acceso a información especializada y actualizada mediante la sindicación de contenidos a todos los profesionales de la red de salud mental en el Principado de Asturias DocSaludMental is a virtual desktop that allows access to expert information and updated from content syndication to all professionals in the mental health network in the Principality of Asturias

Anti-atherosclerotic plants which modulate the phenotype of vascular smooth muscle cells.

Science.gov (United States)

Saleh Al-Shehabi, Tuqa; Iratni, Rabah; Eid, Ali H

2016-10-15

Cardiovascular disease (CVD) remains the leading cause of global death, with atherosclerosis being a major contributor to this mortality. Several mechanisms are implicated in the pathogenesis of this disease. A key element in the development and progression of atherosclerotic lesions is the phenotype of vascular smooth muscle cells. Under pathophysiologic conditions such as injury, these cells switch from a contractile to a synthetic phenotype that often possesses high proliferative and migratory capacities. Despite major advances made in the management and treatment of atherosclerosis, mortality associated with this disease remains high. This mandates that other approaches be sought. Herbal medicine, especially for the treatment of CVD, has been gaining more attention in recent years. This is in no small part due to the evidence-based values associated with the consumption of many plants as well as the relatively cheaper prices, easier access and conventional folk medicine "inherited" over generations. Sections: In this review, we provide a brief introduction about the pathogenesis of atherosclerosis then we highlight the role of vascular smooth muscle cells in this disease, especially when a phenotypic switch of these cells arises. We then thoroughly discuss the various plants that show potentially beneficial effects as anti-atherosclerotic, with prime attention given to herbs and plants that inhibit the phenotypic switch of vascular smooth muscle cells. Accumulating evidence provides the justification for the use of botanicals in the treatment or prevention of atherosclerosis. However, further studies, especially clinical ones, are warranted to better define several pharmacological parameters of these herbs, such as toxicity, tolerability, and efficacy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reconstructing relative genome size of vascular plants through geological time.

Science.gov (United States)

Lomax, Barry H; Hilton, Jason; Bateman, Richard M; Upchurch, Garland R; Lake, Janice A; Leitch, Ilia J; Cromwell, Avery; Knight, Charles A

2014-01-01

The strong positive relationship evident between cell and genome size in both animals and plants forms the basis of using the size of stomatal guard cells as a proxy to track changes in plant genome size through geological time. We report for the first time a taxonomic fine-scale investigation into changes in stomatal guard-cell length and use these data to infer changes in genome size through the evolutionary history of land plants. Our data suggest that many of the earliest land plants had exceptionally large genome sizes and that a predicted overall trend of increasing genome size within individual lineages through geological time is not supported. However, maximum genome size steadily increases from the Mississippian (c. 360 million yr ago (Ma)) to the present. We hypothesise that the functional relationship between stomatal size, genome size and atmospheric CO2 may contribute to the dichotomy reported between preferential extinction of neopolyploids and the prevalence of palaeopolyploidy observed in DNA sequence data of extant vascular plants. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Germination, survival and growth of three vascular plants on biological soil crusts from a Mexican tropical desert.

Science.gov (United States)

Godínez-Alvarez, H; Morín, C; Rivera-Aguilar, V

2012-01-01

Information about the effects of biological soil crusts (BSC) on germination, seedling survival and growth of vascular plants is controversial because they can have positive, neutral or negative effects. This controversy may be because most studies conducted until now have just analysed one or two recruitment stages independently. To understand the BSC effects on vascular plants, it is necessary to consider each stage of the recruitment process and synthesise all this information. The goal of this study was twofold. First, we analyse germination, seedling survival and growth of three vascular plants (Agave marmorata, Prosopis laevigata and Neobuxbaumia tetetzo) on BSC (cyanobacteria and mixed crust) from a tropical desert region of south-central México. Second, we synthesise the information to determine the total effect of BSC on plant species performance. We conducted experiments under controlled conditions to evaluate the proportion of germinated seeds, proportion of surviving seedlings and seedling dry weight in BSC and bare soil. Results showed that BSC have different effects on germination, seedling survival and growth of plant species. Plant species performance was qualitatively higher on BSC than bare soil. The highest performance of A. marmorata and P. laevigata was observed on cyanobacteria and mixed crusts, respectively. The highest performance of N. tetetzo was on both crust types. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

Challenges in tracing the fate and effects of atmospheric polycyclic aromatic hydrocarbon deposition in vascular plants.

Science.gov (United States)

Desalme, Dorine; Binet, Philippe; Chiapusio, Geneviève

2013-05-07

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic pollutants that raise environmental concerns because of their toxicity. Their accumulation in vascular plants conditions harmful consequences to human health because of their position in the food chain. Consequently, understanding how atmospheric PAHs are taken up in plant tissues is crucial for risk assessment. In this review we synthesize current knowledge about PAH atmospheric deposition, accumulation in both gymnosperms and angiosperms, mechanisms of transfer, and ecological and physiological effects. PAHs emitted in the atmosphere partition between gas and particulate phases and undergo atmospheric deposition on shoots and soil. Most PAH concentration data from vascular plant leaves suggest that contamination occurs by both direct (air-leaf) and indirect (air-soil-root) pathways. Experimental studies demonstrate that PAHs affect plant growth, interfering with plant carbon allocation and root symbioses. Photosynthesis remains the most studied physiological process affected by PAHs. Among scientific challenges, identifying specific physiological transfer mechanisms and improving the understanding of plant-symbiont interactions in relation to PAH pollution remain pivotal for both fundamental and applied environmental sciences.

Moss and liverwort xyloglucans contain galacturonic acid and are structurally distinct from the xyloglucans synthesized by hornworts and vascular plants.

Science.gov (United States)

Peña, Maria J; Darvill, Alan G; Eberhard, Stefan; York, William S; O'Neill, Malcolm A

2008-11-01

Xyloglucan is a well-characterized hemicellulosic polysaccharide that is present in the cell walls of all seed-bearing plants. The cell walls of avascular and seedless vascular plants are also believed to contain xyloglucan. However, these xyloglucans have not been structurally characterized. This lack of information is an impediment to understanding changes in xyloglucan structure that occurred during land plant evolution. In this study, xyloglucans were isolated from the walls of avascular (liverworts, mosses, and hornworts) and seedless vascular plants (club and spike mosses and ferns and fern allies). Each xyloglucan was fragmented with a xyloglucan-specific endo-glucanase and the resulting oligosaccharides then structurally characterized using NMR spectroscopy, MALDI-TOF and electrospray mass spectrometry, and glycosyl-linkage and glycosyl residue composition analyses. Our data show that xyloglucan is present in the cell walls of all major divisions of land plants and that these xyloglucans have several common structural motifs. However, these polysaccharides are not identical because specific plant groups synthesize xyloglucans with unique structural motifs. For example, the moss Physcomitrella patens and the liverwort Marchantia polymorpha synthesize XXGGG- and XXGG-type xyloglucans, respectively, with sidechains that contain a beta-D-galactosyluronic acid and a branched xylosyl residue. By contrast, hornworts synthesize XXXG-type xyloglucans that are structurally homologous to the xyloglucans synthesized by many seed-bearing and seedless vascular plants. Our results increase our understanding of the evolution, diversity, and function of structural motifs in land-plant xyloglucans and provide support to the proposal that hornworts are sisters to the vascular plants.

Response of photosynthetic carbon gain to ecosystem retrogression of vascular plants and mosses in the boreal forest.

Science.gov (United States)

Bansal, Sheel; Nilsson, Marie-Charlotte; Wardle, David A

2012-07-01

In the long-term absence of rejuvenating disturbances, forest succession frequently proceeds from a maximal biomass phase to a retrogressive phase characterized by reduced nutrient availability [notably nitrogen (N) and phosphorus (P)] and net primary productivity. Few studies have considered how retrogression induces changes in ecophysiological responses associated with photosynthetic carbon (C) gain, and only for trees. We tested the hypothesis that retrogression would negatively impact photosynthetic C gain of four contrasting species, and that this impact would be greater for vascular plants (i.e., trees and shrubs) than for non-vascular plants (i.e., mosses). We used a 5,000-year-old chronosequence of forested islands in Sweden, where retrogression occurs in the long-term absence of lightning-ignited wildfires. Despite fundamental differences in plant form and ecological niche among species, vascular plants and mosses showed similar ecophysiological responses to retrogression. The most common effects of retrogression were reductions in photosynthesis and respiration per unit foliar N, increases in foliar N, δ(13)C and δ(15)N, and decreases in specific leaf areas. In contrast, photosynthesis per unit mass or area generally did not change along the chronosequence, but did vary many-fold between vascular plants and mosses. The consistent increases in foliar N without corresponding increases in mass- or area-based photosynthesis suggest that other factor(s), such as P co-limitation, light conditions or water availability, may co-regulate C gain in retrogressive boreal forests. Against our predictions, traits of mosses associated with C and N were generally highly responsive to retrogression, which has implications for how mosses influence ecosystem processes in boreal forests.

Shifts in bryophyte carbon isotope ratio across an elevation × soil age matrix on Mauna Loa, Hawaii: do bryophytes behave like vascular plants?

Science.gov (United States)

Waite, Mashuri; Sack, Lawren

2011-05-01

The carbon isotope ratio (δ(13)C) of vascular plant leaf tissue is determined by isotope discrimination, primarily mediated by stomatal and mesophyll diffusion resistances and by photosynthetic rate. These effects lead to predictable trends in leaf δ(13)C across natural gradients of elevation, irradiance and nutrient supply. Less is known about shifts in δ(13)C for bryophytes at landscape scale, as bryophytes lack stomata in the dominant gametophyte phase, and thus lack active control over CO(2) diffusion. Twelve bryophyte species were sampled across a matrix of elevation and soil ages on Mauna Loa, Hawaii Island. We tested hypotheses based on previous findings for vascular plants, which tend to have less negative δ(13)C at higher elevations or irradiances, and for leaves with higher leaf mass per area (LMA). Across the matrix, bryophytes spanned the range of δ(13)C values typical of C(3) vascular plants. Bryophytes were remarkably similar to vascular plants in exhibiting less negative δ(13)C with increasing elevation, and with lower overstory cover; additionally δ(13)C was related to bryophyte canopy projected mass per area, a trait analogous to LMA in vascular plants, also correlated negatively with overstory cover. The similarity of responses of δ(13)C in bryophytes and vascular plants to environmental factors, despite differing morphologies and diffusion pathways, points to a strong direct role of photosynthetic rate in determining δ(13)C variation at the landscape scale.

48 CFR 1329.203-70 - DOC Federal tax exemption.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false DOC Federal tax exemption... CONTRACTING REQUIREMENTS TAXES Federal Excise Taxes 1329.203-70 DOC Federal tax exemption. (a) The Office of... enabling DOC and its contractors to purchase spirits (e.g., specially denatured spirits) tax-free for non...

Vascular plant and vertebrate species richness in national parks of the eastern United States

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Hatfield, Jeffrey S.; Myrick, Kaci E.; Huston, Michael A.; Weckerly, Floyd W.; Green, M. Clay

2013-01-01

Given the estimates that species diversity is diminishing at 50-100 times the normal rate, it is critical that we be able to evaluate changes in species richness in order to make informed decisions for conserving species diversity. In this study, we examined the potential of vascular plant species richness to be used as a surrogate for vertebrate species richness in the classes of amphibians, reptiles, birds, and mammals. Vascular plants, as primary producers, represent the biotic starting point for ecological community structure and are the logical place to start for understanding vertebrate species associations. We used data collected by the United States (US) National Park Service (NPS) on species presence within parks in the eastern US to estimate simple linear regressions between plant species richness and vertebrate richness. Because environmental factors may also influence species diversity, we performed simple linear regressions of species richness versus natural logarithm of park area, park latitude, mean annual precipitation, mean annual temperature, and human population density surrounding the parks. We then combined plant species richness and environmental variables in multiple regressions to determine the variables that remained as significant predictors of vertebrate species richness. As expected, we detected significant relationships between plant species richness and amphibian, bird, and mammal species richness. In some cases, plant species richness was predicted by park area alone. Species richness of mammals was only related to plant species richness. Reptile species richness, on the other hand, was related to plant species richness, park latitude and annual precipitation, while amphibian species richness was related to park latitude, park area, and plant species richness. Thus, plant species richness predicted species richness of different vertebrate groups to varying degrees and should not be used exclusively as a surrogate for vertebrate

Species diversity of vascular plants in Si Phang-nga National Park, Phangnga Province

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Leeratiwong, C.

2005-07-01

Full Text Available A survey of the vascular plants in Si Phang-nga National Park, Phangnga Province, was conducted from September 2002 to August 2003. Five hundred and forty three species of 287 genera and 111 families were collected. The most diverse family was Rubiaceae, 53 species. Four species of these collected plants are endemic to Thailand, Argostemma lobulatum, Aristolochia helix, Crinum thaianum and Mallotus hymenophyllus and three species, Hedyotis hedyotidea, Lipocarpha microcephala and Pterolobium intergum are newly recorded for southern Thailand.

Speciation of Se and DOC in soil solution and their relation to Se bioavailability.

Science.gov (United States)

Weng, Liping; Vega, Flora Alonso; Supriatin, Supriatin; Bussink, Wim; Van Riemsdijk, Willem H

2011-01-01

A 0.01 M CaCl(2) extraction is often used to asses the bioavailability of plant nutrients in soils. However, almost no correlation was found between selenium (Se) in the soil extraction and Se content in grass. The recently developed anion Donnan membrane technique was used to analyze chemical speciation of Se in the 0.01 M CaCl(2) extractions of grassland soils and fractionation of DOC (dissolved organic carbon). The results show that most of Se (67-86%) in the extractions (15 samples) are colloidal-sized Se. Only 13-34% of extractable Se are selenate, selenite and small organic Se (<1 nm). Colloidal Se is, most likely, Se bound to or incorporated in colloidal-sized organic matter. The dominant form of small Se compounds (selenate, selenite/small organic compounds) depends on soil. A total of 47-85% of DOC is colloidal-sized and 15-53% are small organic molecules (<1 nm). In combination with soluble S (sulfur) and/or P (phosphor), concentration of small DOC can explain most of the variability of Se content in grass. The results indicate that mineralization of organic Se is the most important factor that controls Se availability in soils. Competition with sulfate and phosphate needs to be taken into account. Further research is needed to verify if concentration of small DOC is a good indicator of mineralization of soil organic matter.

Evolutionary aspects of non-cell-autonomous regulation in vascular plants: structural background and models to study

Directory of Open Access Journals (Sweden)

Anastasiia I. Evkaikina

2014-02-01

Full Text Available Plasmodesmata (PD serve for the exchange of information in form of miRNA, proteins and mRNA between adjacent cells in the course of plant development. This fundamental role of PD is well established in angiosperms but has not yet been traced back to the evolutionary ancient plant taxa where functional studies lag behind studies of PD structure and ontogenetic origin. There is convincing evidence that the ability to form secondary (post-cytokinesis PD, which can connect any adjacent cells, contrary to primary PD which form during cytokinesis and link only cells of the same lineage, appeared in the evolution of higher plants at least twice: in seed plants and in some representatives of the Lycopodiophyta. The (inability to form secondary PD is manifested in the symplastic organization of the shoot apical meristem (SAM which in most taxa of seedless vascular plants differs dramatically from that in seed plants. Lycopodiophyta appear to be suitable models to analyze the transport of developmental regulators via PD in SAMs with symplastic organization both different from, as well as analogous to, that in angiosperms, and to understand the evolutionary aspects of the role of this transport in the morphogenesis of vascular plant taxa.

ORCHIDEE-SOM: modeling soil organic carbon (SOC) and dissolved organic carbon (DOC) dynamics along vertical soil profiles in Europe

Science.gov (United States)

Camino-Serrano, Marta; Guenet, Bertrand; Luyssaert, Sebastiaan; Ciais, Philippe; Bastrikov, Vladislav; De Vos, Bruno; Gielen, Bert; Gleixner, Gerd; Jornet-Puig, Albert; Kaiser, Klaus; Kothawala, Dolly; Lauerwald, Ronny; Peñuelas, Josep; Schrumpf, Marion; Vicca, Sara; Vuichard, Nicolas; Walmsley, David; Janssens, Ivan A.

2018-03-01

Current land surface models (LSMs) typically represent soils in a very simplistic way, assuming soil organic carbon (SOC) as a bulk, and thus impeding a correct representation of deep soil carbon dynamics. Moreover, LSMs generally neglect the production and export of dissolved organic carbon (DOC) from soils to rivers, leading to overestimations of the potential carbon sequestration on land. This common oversimplified processing of SOC in LSMs is partly responsible for the large uncertainty in the predictions of the soil carbon response to climate change. In this study, we present a new soil carbon module called ORCHIDEE-SOM, embedded within the land surface model ORCHIDEE, which is able to reproduce the DOC and SOC dynamics in a vertically discretized soil to 2 m. The model includes processes of biological production and consumption of SOC and DOC, DOC adsorption on and desorption from soil minerals, diffusion of SOC and DOC, and DOC transport with water through and out of the soils to rivers. We evaluated ORCHIDEE-SOM against observations of DOC concentrations and SOC stocks from four European sites with different vegetation covers: a coniferous forest, a deciduous forest, a grassland, and a cropland. The model was able to reproduce the SOC stocks along their vertical profiles at the four sites and the DOC concentrations within the range of measurements, with the exception of the DOC concentrations in the upper soil horizon at the coniferous forest. However, the model was not able to fully capture the temporal dynamics of DOC concentrations. Further model improvements should focus on a plant- and depth-dependent parameterization of the new input model parameters, such as the turnover times of DOC and the microbial carbon use efficiency. We suggest that this new soil module, when parameterized for global simulations, will improve the representation of the global carbon cycle in LSMs, thus helping to constrain the predictions of the future SOC response to global

Inverse coupling of DOC and nitrate export from soils and streams

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Goodale, Christine

2013-04-01

Over the last two decades, nitrate concentrations in surface waters have decreased across the Northeastern United States and parts of northern Europe. Many hypotheses have been proposed to explain this decrease, but the cause remains unclear. One control may be associated with increasing abundance of dissolved organic carbon (DOC), which in turn may be a result of soil recovery from acidification. Compared across catchments, surface water NO3- decreases sharply with increasing DOC concentration. Here, we used measurements of soil and solution nitrate, DOC, and their isotopic composition (13C-DOC, 15N- and 18O-NO3) to test several related hypotheses that changing acidification affects the release of DOC and bio-available DOC (bDOC) from soil, and that variation in stocks of soil C and release of bDOC partly control NO3- export from forested catchments in New York State, USA. We examined whether DOC and NO3- are both driven by soil C processes that produce inverse coupling at the scale of soil cores as well as across catchments, through comparison of soil and surface water chemistry across nine catchments selected from long-term monitoring networks in the Catskill and Adirondack Mountains. In addition, we conducted a series of soil core leaching experiments to examine the role of acidification and recovery in driving the net production of DOC and NO3- from soils. Over 8 months, soil cores were leached biweekly with simulated rainfall solutions of varying pH (3.6 to 7.0) from additions of H2SO4, CaCO3 and NaOH. These experiments did not yield a pH-induced change in DOC quantity, but did show a change in DOC quality, in that acidified cores released more bio-available DOC with less depleted 13C-DOC than cores with experimentally increased pH. All cores leached substantial amounts of nitrate. Together, these lab- and field comparisons are being used to identify the role of soil production and consumption processes in driving cross-watershed differences in DOC and NO3

CDOM-DOC relationship in contrasted coastal waters : implication for DOC retrieval from ocean color remote sensing observation

OpenAIRE

Vantrepotte, V.; Danhiez, F. P.; Loisel, Hubert; Ouillon, Sylvain; Meriaux, X.; Cauvin, A.; Dessailly, D.

2015-01-01

Increasing our knowledge on dissolved organic carbon (DOC) spatio-temporal distribution in the coastal ocean represents a crucial challenge for better understanding the role of these ecosystems in the global oceanic carbon cycle. The assessment of DOC concentration from the absorption properties of the colored part of the dissolved organic matter (a(cdom)) was investigated from an extensive data set covering a variety of coastal environments. Our results confirmed that variation in the acdom(...

A bHLH-Based Feedback Loop Restricts Vascular Cell Proliferation in Plants.

Science.gov (United States)

Vera-Sirera, Francisco; De Rybel, Bert; Úrbez, Cristina; Kouklas, Evangelos; Pesquera, Marta; Álvarez-Mahecha, Juan Camilo; Minguet, Eugenio G; Tuominen, Hannele; Carbonell, Juan; Borst, Jan Willem; Weijers, Dolf; Blázquez, Miguel A

2015-11-23

Control of tissue dimensions in multicellular organisms requires the precise quantitative regulation of mitotic activity. In plants, where cells are immobile, tissue size is achieved through control of both cell division orientation and mitotic rate. The bHLH transcription factor heterodimer formed by target of monopteros5 (TMO5) and lonesome highway (LHW) is a central regulator of vascular width-increasing divisions. An important unanswered question is how its activity is limited to specify vascular tissue dimensions. Here we identify a regulatory network that restricts TMO5/LHW activity. We show that thermospermine synthase ACAULIS5 antagonizes TMO5/LHW activity by promoting the accumulation of SAC51-LIKE (SACL) bHLH transcription factors. SACL proteins heterodimerize with LHW-therefore likely competing with TMO5/LHW interactions-prevent activation of TMO5/LHW target genes, and suppress the over-proliferation caused by excess TMO5/LHW activity. These findings connect two thus-far disparate pathways and provide a mechanistic understanding of the quantitative control of vascular tissue growth. Copyright © 2015 Elsevier Inc. All rights reserved.

Gardening in the zone of death: an experimental assessment of the absolute elevation limit of vascular plants.

Science.gov (United States)

Dvorský, Miroslav; Chlumská, Zuzana; Altman, Jan; Čapková, Kateřina; Řeháková, Klára; Macek, Martin; Kopecký, Martin; Liancourt, Pierre; Doležal, Jiří

2016-04-13

Vascular plants in the western Tibetan Plateau reach 6000 m--the highest elevation on Earth. Due to the significant warming of the region, plant ranges are expected to shift upwards. However, factors governing maximum elevational limits of plant are unclear. To experimentally assess these factors, we transplanted 12 species from 5750 m to 5900 m (upper edge of vegetation) and 6100 m (beyond range) and monitored their survival for six years. In the first three years (2009-2012), there were plants surviving beyond the regional upper limit of vegetation. This supports the hypothesis of dispersal and/or recruitment limitation. Substantial warming, recorded in-situ during this period, very likely facilitated the survival. The survival was ecologically a non-random process, species better adapted to repeated soil freezing and thawing survived significantly better. No species have survived at 6100 m since 2013, probably due to the extreme snowfall in 2013. In conclusion, apart from the minimum heat requirements, our results show that episodic climatic events are decisive determinants of upper elevational limits of vascular plants.

Physiological, vascular and nanomechanical assessment of hybrid poplar leaf traits in micropropagated plants and plants propagated from root cuttings: A contribution to breeding programs.

Science.gov (United States)

Ďurkovič, Jaroslav; Husárová, Hana; Javoříková, Lucia; Čaňová, Ingrid; Šuleková, Miriama; Kardošová, Monika; Lukáčik, Ivan; Mamoňová, Miroslava; Lagaňa, Rastislav

2017-09-01

Micropropagated plants experience significant stress from rapid water loss when they are transferred from an in vitro culture to either greenhouse or field conditions. This is caused both by inefficient stomatal control of transpiration and the change to a higher light intensity and lower humidity. Understanding the physiological, vascular and biomechanical processes that allow micropropagated plants to modify their phenotype in response to environmental conditions can help to improve both field performance and plant survival. To identify changes between the hybrid poplar [Populus tremula × (Populus × canescens)] plants propagated from in vitro tissue culture and those from root cuttings, we assessed leaf performance for any differences in leaf growth, photosynthetic and vascular traits, and also nanomechanical properties of the tracheary element cell walls. The micropropagated plants showed significantly higher values for leaf area, leaf length, leaf width and leaf dry mass. The greater leaf area and leaf size dimensions resulted from the higher transpiration rate recorded for this stock type. Also, the micropropagated plants reached higher values for chlorophyll a fluorescence parameters and for the nanomechanical dissipation energy of tracheary element cell walls which may indicate a higher damping capacity within the primary xylem tissue under abiotic stress conditions. The performance of the plants propagated from root cuttings was superior for instantaneous water-use efficiency which signifies a higher acclimation capacity to stressful conditions during a severe drought particularly for this stock type. Similarities were found among the majority of the examined leaf traits for both vegetative plant origins including leaf mass per area, stomatal conductance, net photosynthetic rate, hydraulic axial conductivity, indicators of leaf midrib vascular architecture, as well as for the majority of cell wall nanomechanical traits. This research revealed that

The French Muséum national d'histoire naturelle vascular plant herbarium collection dataset

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Le Bras, Gwenaël; Pignal, Marc; Jeanson, Marc L.; Muller, Serge; Aupic, Cécile; Carré, Benoît; Flament, Grégoire; Gaudeul, Myriam; Gonçalves, Claudia; Invernón, Vanessa R.; Jabbour, Florian; Lerat, Elodie; Lowry, Porter P.; Offroy, Bérangère; Pimparé, Eva Pérez; Poncy, Odile; Rouhan, Germinal; Haevermans, Thomas

2017-02-01

We provide a quantitative description of the French national herbarium vascular plants collection dataset. Held at the Muséum national d'histoire naturelle, Paris, it currently comprises records for 5,400,000 specimens, representing 90% of the estimated total of specimens. Ninety nine percent of the specimen entries are linked to one or more images and 16% have field-collecting information available. This major botanical collection represents the results of over three centuries of exploration and study. The sources of the collection are global, with a strong representation for France, including overseas territories, and former French colonies. The compilation of this dataset was made possible through numerous national and international projects, the most important of which was linked to the renovation of the herbarium building. The vascular plant collection is actively expanding today, hence the continuous growth exhibited by the dataset, which can be fully accessed through the GBIF portal or the MNHN database portal (available at: https://science.mnhn.fr/institution/mnhn/collection/p/item/search/form). This dataset is a major source of data for systematics, global plants macroecological studies or conservation assessments.

The French Muséum national d’histoire naturelle vascular plant herbarium collection dataset

Science.gov (United States)

Le Bras, Gwenaël; Pignal, Marc; Jeanson, Marc L.; Muller, Serge; Aupic, Cécile; Carré, Benoît; Flament, Grégoire; Gaudeul, Myriam; Gonçalves, Claudia; Invernón, Vanessa R.; Jabbour, Florian; Lerat, Elodie; Lowry, Porter P.; Offroy, Bérangère; Pimparé, Eva Pérez; Poncy, Odile; Rouhan, Germinal; Haevermans, Thomas

2017-01-01

We provide a quantitative description of the French national herbarium vascular plants collection dataset. Held at the Muséum national d’histoire naturelle, Paris, it currently comprises records for 5,400,000 specimens, representing 90% of the estimated total of specimens. Ninety nine percent of the specimen entries are linked to one or more images and 16% have field-collecting information available. This major botanical collection represents the results of over three centuries of exploration and study. The sources of the collection are global, with a strong representation for France, including overseas territories, and former French colonies. The compilation of this dataset was made possible through numerous national and international projects, the most important of which was linked to the renovation of the herbarium building. The vascular plant collection is actively expanding today, hence the continuous growth exhibited by the dataset, which can be fully accessed through the GBIF portal or the MNHN database portal (available at: https://science.mnhn.fr/institution/mnhn/collection/p/item/search/form). This dataset is a major source of data for systematics, global plants macroecological studies or conservation assessments. PMID:28195585

Fungal root symbionts of high-altitude vascular plants in the Himalayas.

Science.gov (United States)

Kotilínek, Milan; Hiiesalu, Inga; Košnar, Jiří; Šmilauerová, Marie; Šmilauer, Petr; Altman, Jan; Dvorský, Miroslav; Kopecký, Martin; Doležal, Jiří

2017-07-26

Arbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) form symbiotic relationships with plants influencing their productivity, diversity and ecosystem functions. Only a few studies on these fungi, however, have been conducted in extreme elevations and none over 5500 m a.s.l., although vascular plants occur up to 6150 m a.s.l. in the Himalayas. We quantified AMF and DSE in roots of 62 plant species from contrasting habitats along an elevational gradient (3400-6150 m) in the Himalayas using a combination of optical microscopy and next generation sequencing. We linked AMF and DSE communities with host plant evolutionary history, ecological preferences (elevation and habitat type) and functional traits. We detected AMF in elevations up to 5800 m, indicating it is more constrained by extreme conditions than the host plants, which ascend up to 6150 m. In contrast, DSE were found across the entire gradient up to 6150 m. AMF diversity was unimodally related to elevation and positively related to the intensity of AMF colonization. Mid-elevation steppe and alpine plants hosted more diverse AMF communities than plants from deserts and the subnival zone. Our results bring novel insights to the abiotic and biotic filters structuring AMF and DSE communities in the Himalayas.

Vascular Gene Expression: A Hypothesis

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Angélica Concepción eMartínez-Navarro

2013-07-01

Full Text Available The phloem is the conduit through which photoassimilates are distributed from autotrophic to heterotrophic tissues and is involved in the distribution of signaling molecules that coordinate plant growth and responses to the environment. Phloem function depends on the coordinate expression of a large array of genes. We have previously identified conserved motifs in upstream regions of the Arabidopsis genes, encoding the homologs of pumpkin phloem sap mRNAs, displaying expression in vascular tissues. This tissue-specific expression in Arabidopsis is predicted by the overrepresentation of GA/CT-rich motifs in gene promoters. In this work we have searched for common motifs in upstream regions of the homologous genes from plants considered to possess a primitive vascular tissue (a lycophyte, as well as from others that lack a true vascular tissue (a bryophyte, and finally from chlorophytes. Both lycophyte and bryophyte display motifs similar to those found in Arabidopsis with a significantly low E-value, while the chlorophytes showed either a different conserved motif or no conserved motif at all. These results suggest that these same genes are expressed coordinately in non- vascular plants; this coordinate expression may have been one of the prerequisites for the development of conducting tissues in plants. We have also analyzed the phylogeny of conserved proteins that may be involved in phloem function and development. The presence of CmPP16, APL, FT and YDA in chlorophytes suggests the recruitment of ancient regulatory networks for the development of the vascular tissue during evolution while OPS is a novel protein specific to vascular plants.

Doc toxin is a kinase that inactivates elongation factor Tu.

Science.gov (United States)

Cruz, Jonathan W; Rothenbacher, Francesca P; Maehigashi, Tatsuya; Lane, William S; Dunham, Christine M; Woychik, Nancy A

2014-03-14

The Doc toxin from bacteriophage P1 (of the phd-doc toxin-antitoxin system) has served as a model for the family of Doc toxins, many of which are harbored in the genomes of pathogens. We have shown previously that the mode of action of this toxin is distinct from the majority derived from toxin-antitoxin systems: it does not cleave RNA; in fact P1 Doc expression leads to mRNA stabilization. However, the molecular triggers that lead to translation arrest are not understood. The presence of a Fic domain, albeit slightly altered in length and at the catalytic site, provided a clue to the mechanism of P1 Doc action, as most proteins with this conserved domain inactivate GTPases through addition of an adenylyl group (also referred to as AMPylation). We demonstrated that P1 Doc added a single phosphate group to the essential translation elongation factor and GTPase, elongation factor (EF)-Tu. The phosphorylation site was at a highly conserved threonine, Thr-382, which was blocked when EF-Tu was treated with the antibiotic kirromycin. Therefore, we have established that Fic domain proteins can function as kinases. This distinct enzymatic activity exhibited by P1 Doc also solves the mystery of the degenerate Fic motif unique to the Doc family of toxins. Moreover, we have established that all characterized Fic domain proteins, even those that phosphorylate, target pivotal GTPases for inactivation through a post-translational modification at a single functionally critical acceptor site.

Isotope-geochemical studies on fractions of dissolved organic carbon (DOC) for determining the origin and evolution of DOC for purposes of groundwater dating

International Nuclear Information System (INIS)

Geyer, S.

1994-01-01

The laboratory work consisted in developing and testing methods of extraction and enrichment of individual high-purity DOC fractions (fulvic acids, humic acids, and low-molecular substances) with the aim of preparing large quantities of groundwaters (> 1000 l) with low DOC concentrations so as to obtain sufficient sampling material. Chemical characterisation of DOC consisted in an analysis of humic and fulvic acids with regard to element composition (C, H, N, O, S) and inorganic trace elements. Isotopic characterization of the DOC fractions consisted in determining 14 C, 13 C, and 2 H levels. For the first time δ 34 S and δ 15 N relations in humic and fulvic acids dissolved in groundwater were determined. (orig./DG) [de

Google Docs in an Out-of-Class Collaborative Writing Activity

Science.gov (United States)

Zhou, Wenyi; Simpson, Elizabeth; Domizi, Denise Pinette

2012-01-01

Google Docs, an online word processing application, is a promising tool for collaborative learning. However, many college instructors and students lack knowledge to effectively use Google Docs to enhance teaching and learning. Goals of this study include (1) assessing the effectiveness of using Google Docs in an out-of-class collaborative writing…

Removal of terrestrial DOC in aquatic ecosystems of a temperate river network

Science.gov (United States)

Wollheim, W.M.; Stewart, R. J.; Aiken, George R.; Butler, Kenna D.; Morse, Nathaniel B.; Salisbury, J.

2015-01-01

Surface waters play a potentially important role in the global carbon balance. Dissolved organic carbon (DOC) fluxes are a major transfer of terrestrial carbon to river systems, and the fate of DOC in aquatic systems is poorly constrained. We used a unique combination of spatially distributed sampling of three DOC fractions throughout a river network and modeling to quantify the net removal of terrestrial DOC during a summer base flow period. We found that aquatic reactivity of terrestrial DOC leading to net loss is low, closer to conservative chloride than to reactive nitrogen. Net removal occurred mainly from the hydrophobic organic acid fraction, while hydrophilic and transphilic acids showed no net change, indicating that partitioning of bulk DOC into different fractions is critical for understanding terrestrial DOC removal. These findings suggest that river systems may have only a modest ability to alter the amounts of terrestrial DOC delivered to coastal zones.

New records of alien vascular plants from Marion and Prince Edward Islands, sub-Antarctic

NARCIS (Netherlands)

Gremmen, N.J.M.; Smith, V.

1999-01-01

A survey was made of the distribution of introduced vascular plants on Marion and Prince Edward Islands. The results of this survey were compared to results of previous surveys (1965/66, 1975, 1981, 1989). Four new introductions to Marion Island have taken place, three of which involved species that

Assessing the relative bioavailability of DOC in regional groundwater systems

Science.gov (United States)

Chapelle, Francis H.; Bradley, Paul M.; Journey, Celeste A.; McMahon, Peter B.

2013-01-01

It has been hypothesized that the degree to which a hyperbolic relationship exists between concentrations of dissolved organic carbon (DOC) and dissolved oxygen (DO) in groundwater may indicate the relative bioavailability of DOC. This hypothesis was examined for 73 different regional aquifers of the United States using 7745 analyses of groundwater compiled by the National Water Assessment (NAWQA) program of the U.S. Geological Survey. The relative reaction quotient (RRQ), a measure of the curvature of DOC concentrations plotted versus DO concentrations and regressed to a decaying hyperbolic equation, was used to assess the relative bioavailability of DOC. For the basalt aquifer of Oahu, Hawaii, RRQ values were low (0.0013 mM−2), reflecting a nearly random relationship between DOC and DO concentrations. In contrast, on the island of Maui, treated sewage effluent injected into a portion of the basalt aquifer resulted in pronounced hyperbolic DOC-DO behavior and a higher RRQ (142 mM−2). RRQ values for the 73 aquifers correlated positively with mean concentrations of ammonia, dissolved iron, and manganese, and correlated negatively with mean pH. This indicates that greater RRQ values are associated with greater concentrations of the final products of microbial reduction reactions. RRQ values and DOC concentrations were negatively correlated with the thickness of the unsaturated zone (UNST) and depth to the top of the screened interval. Finally, RRQ values were positively correlated with mean annual precipitation (MAP), and the highest observed RRQ values were associated with aquifers receiving MAP rates ranging between 900 and 1300 mm/year. These results are uniformly consistent with the hypothesis that the hyperbolic behavior of DOC-DO plots, as quantified by the RRQ metric, can be an indicator of relative DOC bioavailability in groundwater systems.

Assessing the relative bioavailability of DOC in regional groundwater systems.

Science.gov (United States)

Chapelle, Francis H; Bradley, Paul M; Journey, Celeste A; McMahon, Peter B

2013-01-01

It has been hypothesized that the degree to which a hyperbolic relationship exists between concentrations of dissolved organic carbon (DOC) and dissolved oxygen (DO) in groundwater may indicate the relative bioavailability of DOC. This hypothesis was examined for 73 different regional aquifers of the United States using 7745 analyses of groundwater compiled by the National Water Assessment (NAWQA) program of the U.S. Geological Survey. The relative reaction quotient (RRQ), a measure of the curvature of DOC concentrations plotted versus DO concentrations and regressed to a decaying hyperbolic equation, was used to assess the relative bioavailability of DOC. For the basalt aquifer of Oahu, Hawaii, RRQ values were low (0.0013 mM(-2)), reflecting a nearly random relationship between DOC and DO concentrations. In contrast, on the island of Maui, treated sewage effluent injected into a portion of the basalt aquifer resulted in pronounced hyperbolic DOC-DO behavior and a higher RRQ (142 mM(-2)). RRQ values for the 73 aquifers correlated positively with mean concentrations of ammonia, dissolved iron, and manganese, and correlated negatively with mean pH. This indicates that greater RRQ values are associated with greater concentrations of the final products of microbial reduction reactions. RRQ values and DOC concentrations were negatively correlated with the thickness of the unsaturated zone (UNST) and depth to the top of the screened interval. Finally, RRQ values were positively correlated with mean annual precipitation (MAP), and the highest observed RRQ values were associated with aquifers receiving MAP rates ranging between 900 and 1300 mm/year. These results are uniformly consistent with the hypothesis that the hyperbolic behavior of DOC-DO plots, as quantified by the RRQ metric, can be an indicator of relative DOC bioavailability in groundwater systems. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

Effects of reindeer density on vascular plant diversity on North Scandinavian mountains

Directory of Open Access Journals (Sweden)

Johan Olofsson

2005-04-01

Full Text Available We studied the effects of reindeer grazing on species richness and diversity of vascular plants on dolomite influenced low alpine sites in the species rich northern part of the Scandes using 8 sites with different reindeer densities. Two sites were situated inside Malla Strict Nature Reserve, where reindeer grazing have been totally prohibited since 1981, and strongly restricted since 1950s. The six other sites were located in other species rich hotspot sites standardized to be as similar to the dolomite-influenced sites in Malla Strict Reserve as possible but varying in reindeer densities commonly found in the Fennoscandian mountain chain. Each site with a habitat complex especially rich in rare vascular plants (the Dryas heath – low herb meadow complex was systematically sampled in four plots of 2 m x 10 m. The plots were divided to 20 squares of 1 m x 1 m, and complete species lists of vascular plants were compiled for each of the squares. The first DCA (detrended correspondence analysis axis was strongly related to an index of reindeer grazing, indicating that grazing has a strong impact on the composition of the vegetation. None of the characteristics indices of biodiversity (species richness, evenness or Shannon-Wiener H’ was correlated with reindeer density. The local abundances of categories consisting of relatively rare plants (Ca favored plants and red listed plants of Finland showed significant, positive correlation with the intensity of reindeer grazing. We conclude that even though the density of reindeer has no influence on the total species richness or diversity of vascular plants, reindeer may still be important for regional biodiversity as it seems to favour rare and threatened plants. Moreover, our results imply that standard diversity indices may have limited value in the context of conservation biology, as these indices are equally influenced by rarities and by trivial species.Abstract in Swedish / Sammandrag: Vi

Biochar feedstock and pyrolysis temperature effects on leachate: DOC characteristics and nitrate losses from a Brazilian Cerrado Arenosol mixed with agricultural waste biochars.

Science.gov (United States)

Speratti, Alicia B; Johnson, Mark S; Sousa, Heiriane Martins; Dalmagro, Higo J; Couto, Eduardo Guimarães

2018-04-01

Dissolved organic carbon (DOC) leached from Brazilian Cerrado Arenosols can lead to carbon (C) losses and lower soil fertility, while excessive nutrient, e.g. nitrate (NO 3 - ), leaching can potentially cause water contamination. As biochar has been shown to stabilize C and retain soil nutrients, a greenhouse experiment was conducted to test different biochars' contributions to DOC and NO 3 - leaching from a sandy soil. Biochars were made from four local agricultural waste feedstocks (cotton residue, swine manure, eucalyptus sawmill residue, sugarcane filtercake) pyrolysed at 400, 500 and 600 °C. Biochar was mixed with soil at 5% weight in pots and maize seeds planted. Leachate was collected weekly for six weeks and analyzed for DOC and NO 3 - concentrations, while fluorescence spectroscopy with parallel factor analysis (PARAFAC) was used to interpret DOC characteristics. Cotton and swine manure biochar treatments had higher DOC and NO 3 - losses than eucalyptus biochar, filtercake biochar, and control treatments. Cotton and swine manure biochar treatments at high temperatures lost mostly terrestrial, humified DOC, while swine manure, filtercake, and eucalyptus biochars at low temperatures lost mostly labile, microbially-derived DOC. Through the practical use of fluorescence spectroscopy, our study identified filtercake and eucalyptus biochars as most promising for retaining DOC and NO 3 - in a Cerrado Arenosol, potentially reducing stable C and nutrient losses. Copyright © 2018 Elsevier Ltd. All rights reserved.

Bacterial growth and DOC consumption in a tropical coastal lagoon

Directory of Open Access Journals (Sweden)

V. F. Farjalla

Full Text Available The aims of this research were to determine the main limiting nutrient to bacterial growth in Imboassica lagoon, southeastern Brazil, to estimate the percentage of dissolved organic carbon (DOC available for bacterial growth, and to determine the bacterial growth efficiency (BGE of natural assemblages. Bacterial growth and DOC consumption were determined in batch culture experiments, in which water samples were supplemented with nitrogen and phosphorus together or separately, or incubated without nutrient additions. When added together, N and P stimulated higher bacterial growth rates and production, as well as higher DOC consumption. The BGEs and DOC consumption rates were strongly dependent on the method used to determine bacterial production. The BGE ranged from 11 to 72%. However, only a minor fraction of bulk DOC was consumed by the planktonic bacteria (from 0.7 to 3.4%. The results suggest that low availability of phosphorus and nitrogen coupled with excess organic carbon was the main factor responsible for the relatively low bacterial utilization of DOC in Imboassica lagoon.

Dynamics, chemical properties and bioavailability of DOC in an early successional catchment

Directory of Open Access Journals (Sweden)

U. Risse-Buhl

2013-07-01

Full Text Available The dynamics of dissolved organic carbon (DOC have been intensively studied in mature ecosystems, but little is known about DOC dynamics and the significance of DOC as a substrate for microbial activity in early-successional catchments. We determined the concentration, chemical composition, source, radiocarbon age, and bioavailability of DOC along the hydrological flow path from soil solution to a downstream pond in a recently constructed catchment (Chicken Creek Catchment, Germany. Soil solution, upwelling ground water, stream water, subsurface water in an alluvial fan, and pond water all had high DOC concentrations (averages: 6.0–11.6 mg DOC L–1, despite small carbon stocks in both vegetation and soil of the catchment. Solid-state CPMAS 13C NMR of DOC in upwelling ground water revealed a higher proportion of aromatic compounds (32% and a lower proportion of carbohydrates (33% than in pond water (18% and 45%, respectively. The average 14C age of DOC in upwelling ground water was 2600 to 2900 yr, while organic matter of the Quaternary substrate of the catchment had a 14C age of 3000 to 16 000 yr. Both the 14C age data and 13C NMR spectra suggest that DOC partly derived from organic matter of the Quaternary substrate (about 40 to 90% of the C in the DOC, indicating that both recent and old C of the DOC can support microbial activity during early ecosystem succession. However, in a 70 day incubation experiment, only about 11% of the total DOC was found to be bioavailable. This proportion was irrespective of the water type. Origin of the microbial communities within the catchment (enriched from soil, stream sediment or pond water also had only a marginal effect on overall DOC utilization.

Vascular plants of the Nevada Test Site and Central-Southern Nevada: ecologic and geographic distributions

Energy Technology Data Exchange (ETDEWEB)

Beatley, J.C.

1976-01-01

The physical environment of the Nevada Test Site and surrounding area is described with regard to physiography, geology, soils, and climate. A discussion of plant associations is given for the Mojave Desert, Transition Desert, and Great Basin Desert. The vegetation of disturbed sites is discussed with regard to introduced species as well as endangered and threatened species. Collections of vascular plants were made during 1959 to 1975. The plants, belonging to 1093 taxa and 98 families are listed together with information concerning ecologic and geographic distributions. Indexes to families, genera, and species are included. (HLW)

[Effect of the Runoff-sediment Control of the Xiaolangdi Reservoir on DOC Transport].

Science.gov (United States)

Zhang, Yong-ling; Wang, Ming-shi; Dong, Yu-long

2015-04-01

The sampling was carried out in Sanmenxia hydrological station, Xiaolangdi hydrological station and Huayuankou hydrological station from November 2011 to October 2012. The impact of the runoff-sediment control of the Xiaolangdi reservoir on DOC transport,was analyzed. The results were as follows. DOC contents in Sanmenxia station, Xiaolangdi station and Huayuankou station were 1.97-2.71 mg-L(-1), 1.87-2.76 mg x L(-1) and 2.07-2.93 mg x L(-1), respectively, during the normal operation period of Xiaolangdi Reservoir and Sanmenxia reservoir, and the DOC content in the three reservoirs had obvious seasonal change. DOC contents in the three stations were 2.14-3.32 mg x L(-1), 2.21-2.84 mg x L(-1) and 2.11-2.84 mg x L(-1), respectively, during the runoff-sediment control, and the DOC content in the sediment-releasing period of reservoir was higher than that in the water-releasing period of reservoir. DOC content had no significant correlation with TSS and flow either during the normal operation or during the water-sediment regulation of the reservoir. But the DOC content had significant correlation with water temperature during the normal operation of the reservoir. DOC flux in Sanmenxia station was similar to that in Xiaolangdi station from November to March. DOC flux in Sanmenxia station was obviously less than that in Xiaolangdi station from April to July. And the DOC flux in Sanmenxia station was much higher than that in Xiaolangdi station from August to October. The result showed that DOC was retained from August to October by Xiaolangdi reservoir and discharged from Xiaolangdi reservoir from April to July. The yearly DOC fluxes were 8.6 x 10(10), 9.0 x 10(10) and 9.7 x 10(10) g respectively in Sanmenxia station, Xiaolangdi station and Huayuankou station. The DOC flux of Sanmenxia station was the highest in September, which accounted for 22.0% of the yearly DOC flux, and the DOC flux of Xiaolangdi station was the highest in June, which accounted for 17.6% of the

Doc Toxin Is a Kinase That Inactivates Elongation Factor Tu*

Science.gov (United States)

Cruz, Jonathan W.; Rothenbacher, Francesca P.; Maehigashi, Tatsuya; Lane, William S.; Dunham, Christine M.; Woychik, Nancy A.

2014-01-01

The Doc toxin from bacteriophage P1 (of the phd-doc toxin-antitoxin system) has served as a model for the family of Doc toxins, many of which are harbored in the genomes of pathogens. We have shown previously that the mode of action of this toxin is distinct from the majority derived from toxin-antitoxin systems: it does not cleave RNA; in fact P1 Doc expression leads to mRNA stabilization. However, the molecular triggers that lead to translation arrest are not understood. The presence of a Fic domain, albeit slightly altered in length and at the catalytic site, provided a clue to the mechanism of P1 Doc action, as most proteins with this conserved domain inactivate GTPases through addition of an adenylyl group (also referred to as AMPylation). We demonstrated that P1 Doc added a single phosphate group to the essential translation elongation factor and GTPase, elongation factor (EF)-Tu. The phosphorylation site was at a highly conserved threonine, Thr-382, which was blocked when EF-Tu was treated with the antibiotic kirromycin. Therefore, we have established that Fic domain proteins can function as kinases. This distinct enzymatic activity exhibited by P1 Doc also solves the mystery of the degenerate Fic motif unique to the Doc family of toxins. Moreover, we have established that all characterized Fic domain proteins, even those that phosphorylate, target pivotal GTPases for inactivation through a post-translational modification at a single functionally critical acceptor site. PMID:24448800

Trends in soil solution dissolved organic carbon (DOC) concentrations across European forests

NARCIS (Netherlands)

Camino-Serrano, Marta; Graf Pannatier, Elisabeth; Vicca, Sara; Luyssaert, Sebastiaan; Jonard, Mathieu; Ciais, Philippe; Guenet, Bertrand; Gielen, Bert; Peñuelas, Josep; Sardans, Jordi; Waldner, Peter; Sawicka, Kasia

2016-01-01

Dissolved organic carbon (DOC) in surface waters is connected to DOC in soil solution through hydrological pathways. Therefore, it is expected that long-term dynamics of DOC in surface waters reflect DOC trends in soil solution. However, a multitude of site studies have failed so far to establish

Trends in soil solution dissolved organic carbon (DOC) concentrations across European forests

NARCIS (Netherlands)

Camino-Serrano, M.; Graf Pannatier, E.; Vicca, S.; Luyssaert, S.; Jonard, M.; Ciais, P.; Guenet, B.; Gielen, B.; Peñuelas, J.; Sardans, J.; Waldner, P.; Etzold, S.; Cecchini, G.; Clarke, N.; Galić, Z.; Gandois, L.; Hansen, K.; Johnson, J.; Klinck, U.; Lachmanová, Z.; Lindroos, A.J.; Meesenburg, H.; Nieminen, T.M.; Sanders, T.G.M.; Sawicka, K.; Seidling, W.; Thimonier, A.; Vanguelova, E.; Verstraeten, A.; Vesterdal, L.; Janssens, I.A.

2016-01-01

Dissolved organic carbon (DOC) in surface waters is connected to DOC in soil solution through hydrological pathways. Therefore, it is expected that long-term dynamics of DOC in surface waters reflect DOC trends in soil solution. However, a multitude of site studies have failed so far to establish

Investigating water transport through the xylem network in vascular plants.

Science.gov (United States)

Kim, Hae Koo; Park, Joonghyuk; Hwang, Ildoo

2014-04-01

Our understanding of physical and physiological mechanisms depends on the development of advanced technologies and tools to prove or re-evaluate established theories, and test new hypotheses. Water flow in land plants is a fascinating phenomenon, a vital component of the water cycle, and essential for life on Earth. The cohesion-tension theory (CTT), formulated more than a century ago and based on the physical properties of water, laid the foundation for our understanding of water transport in vascular plants. Numerous experimental tools have since been developed to evaluate various aspects of the CTT, such as the existence of negative hydrostatic pressure. This review focuses on the evolution of the experimental methods used to study water transport in plants, and summarizes the different ways to investigate the diversity of the xylem network structure and sap flow dynamics in various species. As water transport is documented at different scales, from the level of single conduits to entire plants, it is critical that new results be subjected to systematic cross-validation and that findings based on different organs be integrated at the whole-plant level. We also discuss the functional trade-offs between optimizing hydraulic efficiency and maintaining the safety of the entire transport system. Furthermore, we evaluate future directions in sap flow research and highlight the importance of integrating the combined effects of various levels of hydraulic regulation.

Testing the Efficacy of DNA Barcodes for Identifying the Vascular Plants of Canada.

Science.gov (United States)

Braukmann, Thomas W A; Kuzmina, Maria L; Sills, Jesse; Zakharov, Evgeny V; Hebert, Paul D N

2017-01-01

Their relatively slow rates of molecular evolution, as well as frequent exposure to hybridization and introgression, often make it difficult to discriminate species of vascular plants with the standard barcode markers (rbcL, matK, ITS2). Previous studies have examined these constraints in narrow geographic or taxonomic contexts, but the present investigation expands analysis to consider the performance of these gene regions in discriminating the species in local floras at sites across Canada. To test identification success, we employed a DNA barcode reference library with sequence records for 96% of the 5108 vascular plant species known from Canada, but coverage varied from 94% for rbcL to 60% for ITS2 and 39% for matK. Using plant lists from 27 national parks and one scientific reserve, we tested the efficacy of DNA barcodes in identifying the plants in simulated species assemblages from six biogeographic regions of Canada using BLAST and mothur. Mean pairwise distance (MPD) and mean nearest taxon distance (MNTD) were strong predictors of barcode performance for different plant families and genera, and both metrics supported ITS2 as possessing the highest genetic diversity. All three genes performed strongly in assigning the taxa present in local floras to the correct genus with values ranging from 91% for rbcL to 97% for ITS2 and 98% for matK. However, matK delivered the highest species discrimination (~81%) followed by ITS2 (~72%) and rbcL (~44%). Despite the low number of plant taxa in the Canadian Arctic, DNA barcodes had the least success in discriminating species from this biogeographic region with resolution ranging from 36% with rbcL to 69% with matK. Species resolution was higher in the other settings, peaking in the Woodland region at 52% for rbcL and 87% for matK. Our results indicate that DNA barcoding is very effective in identifying Canadian plants to a genus, and that it performs well in discriminating species in regions where floristic diversity is

Lake sediment multi-taxon DNA from North Greenland records early post-glacial appearance of vascular plants and accurately tracks environmental changes

DEFF Research Database (Denmark)

Epp, L. S.; Gussarova, C.; Boessenkool, S.

2015-01-01

temperatures. Lake sediments contain DNA paleorecords of the surrounding ecosystems and can be used to retrieve a variety of organismal groups from a single sample. In this study, we analyzed vascular plant, bryophyte, algal (in particular diatom) and copepod DNA retrieved from a sediment core spanning...... phases, and distinct temporal changes in plant presence were recovered. The plant DNA was mostly in agreement with expected vegetation history, but very early occurrences of vascular plants, including the woody Empetrum nigrum, document terrestrial vegetation very shortly after glacial retreat. Our study...... core. Our DNA record was stratigraphically coherent, with no indication of leaching between layers, and our cross-taxon comparisons were in accordance with previously inferred local ecosystem changes. Authentic ancient plant DNA was retrieved from nearly all layers, both from the marine and the limnic...

The ALDH21 gene found in lower plants and some vascular plants codes for a NADP+ -dependent succinic semialdehyde dehydrogenase.

Science.gov (United States)

Kopečná, Martina; Vigouroux, Armelle; Vilím, Jan; Končitíková, Radka; Briozzo, Pierre; Hájková, Eva; Jašková, Lenka; von Schwartzenberg, Klaus; Šebela, Marek; Moréra, Solange; Kopečný, David

2017-10-01

Lower plant species including some green algae, non-vascular plants (bryophytes) as well as the oldest vascular plants (lycopods) and ferns (monilophytes) possess a unique aldehyde dehydrogenase (ALDH) gene named ALDH21, which is upregulated during dehydration. However, the gene is absent in flowering plants. Here, we show that ALDH21 from the moss Physcomitrella patens codes for a tetrameric NADP + -dependent succinic semialdehyde dehydrogenase (SSALDH), which converts succinic semialdehyde, an intermediate of the γ-aminobutyric acid (GABA) shunt pathway, into succinate in the cytosol. NAD + is a very poor coenzyme for ALDH21 unlike for mitochondrial SSALDHs (ALDH5), which are the closest related ALDH members. Structural comparison between the apoform and the coenzyme complex reveal that NADP + binding induces a conformational change of the loop carrying Arg-228, which seals the NADP + in the coenzyme cavity via its 2'-phosphate and α-phosphate groups. The crystal structure with the bound product succinate shows that its carboxylate group establishes salt bridges with both Arg-121 and Arg-457, and a hydrogen bond with Tyr-296. While both arginine residues are pre-formed for substrate/product binding, Tyr-296 moves by more than 1 Å. Both R121A and R457A variants are almost inactive, demonstrating a key role of each arginine in catalysis. Our study implies that bryophytes but presumably also some green algae, lycopods and ferns, which carry both ALDH21 and ALDH5 genes, can oxidize SSAL to succinate in both cytosol and mitochondria, indicating a more diverse GABA shunt pathway compared with higher plants carrying only the mitochondrial ALDH5. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Silicon in vascular plants: uptake, transport and its influence on mineral stress under acidic conditions.

Science.gov (United States)

Pontigo, Sofía; Ribera, Alejandra; Gianfreda, Liliana; de la Luz Mora, María; Nikolic, Miroslav; Cartes, Paula

2015-07-01

So far, considerable advances have been achieved in understanding the mechanisms of Si uptake and transport in vascular plants. This review presents a comprehensive update about this issue, but also provides the new insights into the role of Si against mineral stresses that occur in acid soils. Such information could be helpful to understand both the differential Si uptake ability as well as the benefits of this mineral element on plants grown under acidic conditions. Silicon (Si) has been widely recognized as a beneficial element for many plant species, especially under stress conditions. In the last few years, great efforts have been made to elucidate the mechanisms involved in uptake and transport of Si by vascular plants and recently, different Si transporters have been identified. Several researches indicate that Si can alleviate various mineral stresses in plants growing under acidic conditions, including aluminium (Al) and manganese (Mn) toxicities as well as phosphorus (P) deficiency all of which are highly detrimental to crop production. This review presents recent findings concerning the influence of uptake and transport of Si on mineral stress under acidic conditions because a knowledge of this interaction provides the basis for understanding the role of Si in mitigating mineral stress in acid soils. Currently, only four Si transporters have been identified and there is little information concerning the response of Si transporters under stress conditions. More investigations are therefore needed to establish whether there is a relationship between Si transporters and the benefits of Si to plants subjected to mineral stress. Evidence presented suggests that Si supply and its subsequent accumulation in plant tissues could be exploited as a strategy to improve crop productivity on acid soils.

Vascular Plant and Vertebrate Inventory of Organ Pipe Cactus National Monument

Science.gov (United States)

Schmidt, Cecilia A.; Powell, Brian F.; Halvorson, William L.

2007-01-01

Executive Summary We summarized inventory and monitoring efforts for plants and vertebrates at Organ Pipe Cactus National Monument (NM) in Arizona. We used data from previous research to compile complete species lists for the monument and to assess inventory completeness. There have been 1,031 species of plants and vertebrates observed at the monument. Most of the species on the list are documented by voucher specimens. There are 59 non-native species established in the monument: one mammal, three birds, and 55 non-native plants. Most non-native plant species were first recorded along roads. In each taxon-specific chapter, we highlight areas that contribute disproportionately to species richness or that have unique species for the monument. Of particular importance are Quitobaquito Springs and Pond, which are responsible for the monument having one of the highest number of bird species in the Sonoran Desert Network of parks. Quitobaquito also contains the only fish in the monument, the endangered Quitobaquito pupfish (Cyprinodon eremus). Other important resources for the plants and vertebrates include the xeroriparian washes (e.g., Alamo Canyon) and the Ajo Mountains. Based on the review of past studies, we believe the inventories of vascular plants and vertebrates are nearly complete and that the monument has one of the most complete inventories of any unit in the Sonoran Desert Network.

Gravity sensing and signal transduction in vascular plant primary roots.

Science.gov (United States)

Baldwin, Katherine L; Strohm, Allison K; Masson, Patrick H

2013-01-01

During gravitropism, the potential energy of gravity is converted into a biochemical signal. How this transfer occurs remains one of the most exciting mysteries in plant cell biology. New experiments are filling in pieces of the puzzle. In this review, we introduce gravitropism and give an overview of what we know about gravity sensing in roots of vascular plants, with special highlight on recent papers. When plant roots are reoriented sideways, amyloplast resedimentation in the columella cells is a key initial step in gravity sensing. This process somehow leads to cytoplasmic alkalinization of these cells followed by relocalization of auxin efflux carriers (PINs). This changes auxin flow throughout the root, generating a lateral gradient of auxin across the cap that upon transmission to the elongation zone leads to differential cell elongation and gravibending. We will present the evidence for and against the following players having a role in transferring the signal from the amyloplast sedimentation into the auxin signaling cascade: mechanosensitive ion channels, actin, calcium ions, inositol trisphosphate, receptors/ligands, ARG1/ARL2, spermine, and the TOC complex. We also outline auxin transport and signaling during gravitropism.

Survey of protected vascular plants on the Oak Ridge Reservation, Oak Ridge, Tennessee

Energy Technology Data Exchange (ETDEWEB)

Awl, D.J.; Pounds, L.R.; Rosensteel, B.A.; King, A.L.; Hamlett, P.A.

1996-06-01

Vascular plant surveys were initiated during fiscal year 1992 by the environmentally sensitive areas program to determine the baseline condition of threatened and endangered (T&E) vascular plant species on the Oak Ridge Reservation (ORR). T&E species receive protection under federal and state regulations. In addition, the National Environmental Policy Act (NEPA) requires that federally-funded projects avoid or mitigate impacts to listed species. T&E plant species found on or near the U.S. Department of Energy`s (DOE) Oak Ridge Reservation (ORR) are identified. Twenty-eight species identified on the ORR are listed by the Tennessee Department of Environment and Conservation as either endangered, threatened, or of special concern. Four of these have been under review by the U.S. Fish and Wildlife Service for possible listing (listed in the formerly-used C2 candidate category). Additional species listed by the state occur near and may be present on the ORR. A range of habitats support the rare taxa on the ORR: river bluffs, sinkholes, calcareous barrens, wetlands, utility corridors, and forests. The list of T&E plant species and their locations on the ORR should be considered provisional because the entire ORR has not been surveyed, and state and federal status of all species continues to be updated. The purpose of this document is to present information on the listed T&E plant species currently known to occur on the ORR as well as listed species potentially occurring on the ORR based on geographic range and habitat availability. For the purpose of this report, {open_quotes}T&E species{close_quotes} include all federal- and state-listed species, including candidates for listing, and species of special concern. Consideration of T&E plant habitats is an important component of resource management and land-use planning; protection of rare species in their natural habitat is the best method of ensuring their long-term survival.

Survey of protected vascular plants on the Oak Ridge Reservation, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Awl, D.J.; Pounds, L.R.; Rosensteel, B.A.; King, A.L.; Hamlett, P.A.

1996-06-01

Vascular plant surveys were initiated during fiscal year 1992 by the environmentally sensitive areas program to determine the baseline condition of threatened and endangered (T ampersand E) vascular plant species on the Oak Ridge Reservation (ORR). T ampersand E species receive protection under federal and state regulations. In addition, the National Environmental Policy Act (NEPA) requires that federally-funded projects avoid or mitigate impacts to listed species. T ampersand E plant species found on or near the U.S. Department of Energy's (DOE) Oak Ridge Reservation (ORR) are identified. Twenty-eight species identified on the ORR are listed by the Tennessee Department of Environment and Conservation as either endangered, threatened, or of special concern. Four of these have been under review by the U.S. Fish and Wildlife Service for possible listing (listed in the formerly-used C2 candidate category). Additional species listed by the state occur near and may be present on the ORR. A range of habitats support the rare taxa on the ORR: river bluffs, sinkholes, calcareous barrens, wetlands, utility corridors, and forests. The list of T ampersand E plant species and their locations on the ORR should be considered provisional because the entire ORR has not been surveyed, and state and federal status of all species continues to be updated. The purpose of this document is to present information on the listed T ampersand E plant species currently known to occur on the ORR as well as listed species potentially occurring on the ORR based on geographic range and habitat availability. For the purpose of this report, open-quotes T ampersand E speciesclose quotes include all federal- and state-listed species, including candidates for listing, and species of special concern. Consideration of T ampersand E plant habitats is an important component of resource management and land-use planning; protection of rare species in their natural habitat is the best method of ensuring their

Insights and issues with simulating terrestrial DOC loading of Arctic river networks.

Science.gov (United States)

Kicklighter, David W; Hayes, Daniel J; McClelland, James W; Peterson, Bruce J; McGuire, A David; Melillo, Jerry M

2013-12-01

Terrestrial carbon dynamics influence the contribution of dissolved organic carbon (DOC) to river networks in addition to hydrology. In this study, we use a biogeochemical process model to simulate the lateral transfer of DOC from land to the Arctic Ocean via riverine transport. We estimate that, over the 20th century, the pan-Arctic watershed has contributed, on average, 32 Tg C/yr of DOC to river networks emptying into the Arctic Ocean with most of the DOC coming from the extensive area of boreal deciduous needle-leaved forests and forested wetlands in Eurasian watersheds. We also estimate that the rate of terrestrial DOC loading has been increasing by 0.037 Tg C/yr2 over the 20th century primarily as a result of climate-induced increases in water yield. These increases have been offset by decreases in terrestrial DOC loading caused by wildfires. Other environmental factors (CO2 fertilization, ozone pollution, atmospheric nitrogen deposition, timber harvest, agriculture) are estimated to have relatively small effects on terrestrial DOC loading to Arctic rivers. The effects of the various environmental factors on terrestrial carbon dynamics have both offset and enhanced concurrent effects on hydrology to influence terrestrial DOC loading and may be changing the relative importance of terrestrial carbon dynamics on this carbon flux. Improvements in simulating terrestrial DOC loading to pan-Arctic rivers in the future will require better information on the production and consumption of DOC within the soil profile, the transfer of DOC from land to headwater streams, the spatial distribution of precipitation and its temporal trends, carbon dynamics of larch-dominated ecosystems in eastern Siberia, and the role of industrial organic effluents on carbon budgets of rivers in western Russia.

Insights and issues with simulating terrestrial DOC loading of Arctic river networks

Science.gov (United States)

Kicklighter, David W.; Hayes, Daniel J.; McClelland, James W.; Peterson, Bruce J.; McGuire, A. David; Melillo, Jerry M.

2013-01-01

Terrestrial carbon dynamics influence the contribution of dissolved organic carbon (DOC) to river networks in addition to hydrology. In this study, we use a biogeochemical process model to simulate the lateral transfer of DOC from land to the Arctic Ocean via riverine transport. We estimate that, over the 20th century, the pan-Arctic watershed has contributed, on average, 32 Tg C/yr of DOC to river networks emptying into the Arctic Ocean with most of the DOC coming from the extensive area of boreal deciduous needle-leaved forests and forested wetlands in Eurasian watersheds. We also estimate that the rate of terrestrial DOC loading has been increasing by 0.037 Tg C/yr2 over the 20th century primarily as a result of climate-induced increases in water yield. These increases have been offset by decreases in terrestrial DOC loading caused by wildfires. Other environmental factors (CO2 fertilization, ozone pollution, atmospheric nitrogen deposition, timber harvest, agriculture) are estimated to have relatively small effects on terrestrial DOC loading to Arctic rivers. The effects of the various environmental factors on terrestrial carbon dynamics have both offset and enhanced concurrent effects on hydrology to influence terrestrial DOC loading and may be changing the relative importance of terrestrial carbon dynamics on this carbon flux. Improvements in simulating terrestrial DOC loading to pan-Arctic rivers in the future will require better information on the production and consumption of DOC within the soil profile, the transfer of DOC from land to headwater streams, the spatial distribution of precipitation and its temporal trends, carbon dynamics of larch-dominated ecosystems in eastern Siberia, and the role of industrial organic effluents on carbon budgets of rivers in western Russia.

Plant physiology in theory and practice: an analysis of the WBE model for vascular plants.

Science.gov (United States)

Petit, Giai; Anfodillo, Tommaso

2009-07-07

The theoretical model of West, Brown and Enquist (hereafter WBE) proposed the fractal geometry of the transport system as the origin of the allometric scaling laws observed in nature. The WBE model has either been criticized for some restrictive and biologically unrealistic constraints or its reliability debated on the evidence of empirical tests. In this work, we revised the structure of the WBE model for vascular plants, highlighting some critical assumptions and simplifications and discuss them with regard to empirical evidence from plant anatomy and physiology. We conclude that the WBE model had the distinct merit of shedding light on some important features such as conduit tapering. Nonetheless, it is over-simplistic and a revised model would be desirable with an ontogenetic perspective that takes some important phenomena into account, such as the transformation of the inner sapwood into heartwood and the effect of hydraulic constraints in limiting the growth in height.

Vascular plants of Mt. Dosolsan in the Demilitarized Zone Civilian Control Line

Directory of Open Access Journals (Sweden)

Jong Bin An

2018-06-01

Full Text Available This study is aimed at identifying the distribution of vascular plants growing at Mt. Dosolsan in Yanggu-gun, Gangwon-do. Field surveys were conducted for each season from March 2014 to November 2016. The flora of study area is found to consist of 516 taxa, 91 families, 296 genus, 455 species, four subspecies, 50 varieties, and seven forma. Rare plants were found to be of 31 taxa. Among them, rare plant species consisted of critically endangered species (CR degree: 2 (Lilium dauricum Ker Gawl., Cypripedium macranthos Sw., endangered species (EN degree: 5 (Loranthus tanakae Franch. & Sav. etc., vulnerable species (VU degree: 7 (Dryopteris laeta (Kom. C.Chr. etc., and least concerned (LC degree: 17 (Botrychium virginianum (L. Sw. etc.. In all the surveyed areas, a total of 20 taxa (Pseudostellaria setulosa Ohwi etc. were found to be endemic to Korea. The floristic special plants found in the surveyed areas were two taxa of grade V, 24 taxa of grade IV, and 31 taxa of grade III. The naturalized plants were identified as 15 taxa and included Chenopodium album L., Lotus corniculatus L., Robinia pseudoacacia L. etc.

Dynamic analysis on cavitation and embolization in vascular plants under tension

Science.gov (United States)

Ryu, Jeongeun; Hwang, Bae Geun; Kim, Yangmin; Lee, Sang Joon

2014-11-01

Plants can transport sap water from the soil to the tip of their leaves using the tensile forces created by leaf transpiration without any mechanical pumps. However, the high tension adversely induces a thermodynamically metastable state in sap water with negative pressure and gas bubbles are prone to be formed in xylem vessels. Cavitation easily breaks down continuous water columns and grows into embolization, which limits water transport through xylem vessels. Meanwhile, the repair process of embolization is closely related to water management and regulation of sap flow in plants. In this study, the cavitation and embolization phenomena of liquid water in vascular plants and a physical model system are experimentally and theoretically investigated in detail under in vivo and in vitro conditions. This study will not only shed light on the understanding of these multiphase flows under tension but also provide a clue to solve cavitation problems in micro-scale conduits and microfluidic network systems. This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2008-0061991).

48 CFR 1323.404-70 - DOC affirmative procurement program.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false DOC affirmative procurement program. 1323.404-70 Section 1323.404-70 Federal Acquisition Regulations System DEPARTMENT OF..., OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Use of Recovered Materials 1323.404-70 DOC affirmative procurement...

The study of distribution characteristics of vascular and naturalized plants in Dokdo, South Korea

Directory of Open Access Journals (Sweden)

Su-Young Jung

2014-06-01

Full Text Available This study was performed to investigate the distribution of vascular plants and the characteristics of naturalized plants in Dokdo Island, South Korea. The survey was conducted a total of 5 times from June 2012 to September 2013. The number of plants confirmed in this study was 60 taxa in total: 29 families, 49 genera, 55 species, 2 subspecies and 3 varieties. To classify them by regional groups, 53 taxa were confirmed in the Dongdo and 38 taxa were confirmed in the Seodo. Among them, the distribution of Stellaria neglecta Weihe and Puccinellia nipponica Ohwi was first discovered in this study. The naturalized plants distributed in Dokdo was 7 taxa: Chenopodium album L., Sonchus asper (L. Hill, Sonchus oleraceus L., Ipomoea purpurea Roth, Brassica juncea (L. Czern., etc. Overall, concerns over the naturalized plants in Dokdo are high regardless of the scale of their distribution and the appearance frequency.

Reliability and Validity of the Dyadic Observed Communication Scale (DOCS).

Science.gov (United States)

Hadley, Wendy; Stewart, Angela; Hunter, Heather L; Affleck, Katelyn; Donenberg, Geri; Diclemente, Ralph; Brown, Larry K

2013-02-01

We evaluated the reliability and validity of the Dyadic Observed Communication Scale (DOCS) coding scheme, which was developed to capture a range of communication components between parents and adolescents. Adolescents and their caregivers were recruited from mental health facilities for participation in a large, multi-site family-based HIV prevention intervention study. Seventy-one dyads were randomly selected from the larger study sample and coded using the DOCS at baseline. Preliminary validity and reliability of the DOCS was examined using various methods, such as comparing results to self-report measures and examining interrater reliability. Results suggest that the DOCS is a reliable and valid measure of observed communication among parent-adolescent dyads that captures both verbal and nonverbal communication behaviors that are typical intervention targets. The DOCS is a viable coding scheme for use by researchers and clinicians examining parent-adolescent communication. Coders can be trained to reliably capture individual and dyadic components of communication for parents and adolescents and this complex information can be obtained relatively quickly.

Automatisierte Artikelbestellverwaltung: Doctor-Doc – ein bibliothekarisches Verwaltungswerkzeug / Automation in Interlibrary Loan: Doctor-Doc – a tool for librarians

Directory of Open Access Journals (Sweden)

Fischer, Markus

2010-05-01

Full Text Available Interlibrary loan has always been an important service to supplement own library holdings.To organize and standardize the order process of journal articles for 6 hospitals, we did create an online tool for the Solothurner Spitäler AG. The resulting application is available for libraries free of charge under http://www.doctor-doc.com/. The application is maintained and will be further developed by an association founded specially for this purpose. Doctor-Doc is not a supplier of articles, but rather a platform to organize orders at existing suppliers like Subito, British Library or any other supplying libraries. Doctor-Doc is OpenURL compliant and is able to resolve identifiers like PMIDs. In combination with an existing account from the german EZB, libraries can use the application as a linkresolver.The application has become an essential tool to efficiently manage interlibrary loan for the Solothurner Spitäler AG. The tool is also used by many libraries in Germany and Switzerland.

Bacterial diversity in rhizosphere soil from Antarctic vascular plants of Admiralty Bay, maritime Antarctica.

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Teixeira, Lia C R S; Peixoto, Raquel S; Cury, Juliano C; Sul, Woo Jun; Pellizari, Vivian H; Tiedje, James; Rosado, Alexandre S

2010-08-01

The Antarctic is a pristine environment that contributes to the maintenance of the global climate equilibrium. The harsh conditions of this habitat are fundamental to selecting those organisms able to survive in such an extreme habitat and able to support the relatively simple ecosystems. The DNA of the microbial community associated with the rhizospheres of Deschampsia antarctica Desv (Poaceae) and Colobanthus quitensis (Kunth) BartI (Caryophyllaceae), the only two native vascular plants that are found in Antarctic ecosystems, was evaluated using a 16S rRNA multiplex 454 pyrosequencing approach. This analysis revealed similar patterns of bacterial diversity between the two plant species from different locations, arguing against the hypothesis that there would be differences between the rhizosphere communities of different plants. Furthermore, the phylum distribution presented a peculiar pattern, with a bacterial community structure different from those reported of many other soils. Firmicutes was the most abundant phylum in almost all the analyzed samples, and there were high levels of anaerobic representatives. Also, some phyla that are dominant in most temperate and tropical soils, such as Acidobacteria, were rarely found in the analyzed samples. Analyzing all the sample libraries together, the predominant genera found were Bifidobacterium (phylum Actinobacteria), Arcobacter (phylum Proteobacteria) and Faecalibacterium (phylum Firmicutes). To the best of our knowledge, this is the first major bacterial sequencing effort of this kind of soil, and it revealed more than expected diversity within these rhizospheres of both maritime Antarctica vascular plants in Admiralty Bay, King George Island, which is part of the South Shetlands archipelago.

Sample sequencing of vascular plants demonstrates widespread conservation and divergence of microRNAs.

Science.gov (United States)

Chávez Montes, Ricardo A; de Fátima Rosas-Cárdenas, Flor; De Paoli, Emanuele; Accerbi, Monica; Rymarquis, Linda A; Mahalingam, Gayathri; Marsch-Martínez, Nayelli; Meyers, Blake C; Green, Pamela J; de Folter, Stefan

2014-04-23

Small RNAs are pivotal regulators of gene expression that guide transcriptional and post-transcriptional silencing mechanisms in eukaryotes, including plants. Here we report a comprehensive atlas of sRNA and miRNA from 3 species of algae and 31 representative species across vascular plants, including non-model plants. We sequence and quantify sRNAs from 99 different tissues or treatments across species, resulting in a data set of over 132 million distinct sequences. Using miRBase mature sequences as a reference, we identify the miRNA sequences present in these libraries. We apply diverse profiling methods to examine critical sRNA and miRNA features, such as size distribution, tissue-specific regulation and sequence conservation between species, as well as to predict putative new miRNA sequences. We also develop database resources, computational analysis tools and a dedicated website, http://smallrna.udel.edu/. This study provides new insights on plant sRNAs and miRNAs, and a foundation for future studies.

DOC concentrations across a depth-dependent light gradient on a Caribbean coral reef

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Benjamin Mueller

2017-06-01

Full Text Available Photosynthates released by benthic primary producers (BPP, such as reef algae and scleractinian corals, fuel the dissolved organic carbon (DOC production on tropical coral reefs. DOC concentrations near BPP have repeatedly been observed to be elevated compared to those in the surrounding water column. As the DOC release of BPP increases with increasing light availability, elevated DOC concentrations near them will, in part, also depend on light availability. Consequently, DOC concentrations are likely to be higher on the shallow, well-lit reef terrace than in deeper sections on the fore reef slope. We measured in situ DOC concentrations and light intensity in close proximity to the reef alga Dictyota sp. and the scleractinian coral Orbicella faveolata along a depth-dependent light gradient from 5 to 20 m depth and compared these to background concentrations in the water column. At 10 m (intermediate light, DOC concentrations near Dictyota sp. were elevated by 15 µmol C L−1 compared to background concentrations in the water column, but not at 5 and 20 m (high and low light, respectively, or near O. faveolata at any of the tested depths. DOC concentrations did not differ between depths and thereby light environments for any of the tested water types. However, water type and depth appear to jointly affect in situ DOC concentrations across the tested depth-dependent light gradient. Corroborative ex situ measurements of excitation pressure on photosystem II suggest that photoinhibition in Dictyota sp. is likely to occur at light intensities that are commonly present on Curaçaoan coral reefs under high light levels at 5 m depth during midday. Photoinhibition may have thereby reduced the DOC release of Dictyota sp. and DOC concentrations in its close proximity. Our results indicate that the occurrence of elevated DOC concentrations did not follow a natural light gradient across depth. Instead, a combination of multiple factors, such as water type

DOC concentrations across a depth-dependent light gradient on a Caribbean coral reef.

Science.gov (United States)

Mueller, Benjamin; Meesters, Erik H; van Duyl, Fleur C

2017-01-01

Photosynthates released by benthic primary producers (BPP), such as reef algae and scleractinian corals, fuel the dissolved organic carbon (DOC) production on tropical coral reefs. DOC concentrations near BPP have repeatedly been observed to be elevated compared to those in the surrounding water column. As the DOC release of BPP increases with increasing light availability, elevated DOC concentrations near them will, in part, also depend on light availability. Consequently, DOC concentrations are likely to be higher on the shallow, well-lit reef terrace than in deeper sections on the fore reef slope. We measured in situ DOC concentrations and light intensity in close proximity to the reef alga Dictyota sp. and the scleractinian coral Orbicella faveolata along a depth-dependent light gradient from 5 to 20 m depth and compared these to background concentrations in the water column. At 10 m (intermediate light), DOC concentrations near Dictyota sp. were elevated by 15 µmol C L -1 compared to background concentrations in the water column, but not at 5 and 20 m (high and low light, respectively), or near O. faveolata at any of the tested depths. DOC concentrations did not differ between depths and thereby light environments for any of the tested water types. However, water type and depth appear to jointly affect in situ DOC concentrations across the tested depth-dependent light gradient. Corroborative ex situ measurements of excitation pressure on photosystem II suggest that photoinhibition in Dictyota sp. is likely to occur at light intensities that are commonly present on Curaçaoan coral reefs under high light levels at 5 m depth during midday. Photoinhibition may have thereby reduced the DOC release of Dictyota sp. and DOC concentrations in its close proximity. Our results indicate that the occurrence of elevated DOC concentrations did not follow a natural light gradient across depth. Instead, a combination of multiple factors, such as water type, light

Arbuscular mycorrhizal fungi associations of vascular plants confined to river valleys: towards understanding the river corridor plant distribution.

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Nobis, Agnieszka; Błaszkowski, Janusz; Zubek, Szymon

2015-01-01

The group of river corridor plants (RCP) includes vascular plant species which grow mainly or exclusively in the valleys of large rivers. Despite the long recognized fact that some plant species display a corridor-like distribution pattern in Central Europe, there is still no exhaustive explanation of the mechanisms generating this peculiar distribution. The main goal of this study was therefore to investigate whether arbuscular mycorrhizal fungi (AMF) and fungal root endophytes influence the RCP distribution. Arbuscular mycorrhizae (AM) were observed in 19 out of 33 studied RCP. Dark septate endophytes (DSE) and Olpidium spp. were recorded with low abundance in 15 and 10 plant species, respectively. The spores of AMF were found only in 32% of trap cultures established from the soils collected in the river corridor habitats. In total, six widespread AMF species were identified. Because the percentage of non-mycorrhizal species in the group of RCP is significant and the sites in river corridors are characterized by low AMF species diversity, RCP can be outcompeted outside river valleys by the widespread species that are able to benefit from AM associations in more stable plant-AMF communities in non-river habitats.

Irrigation of DOC-rich liquid promotes potential denitrification rate and decreases N

NARCIS (Netherlands)

Qin, Shuping; Hu, Chunsheng; Clough, Tim J.; Luo, Jiafa; Oenema, Oene; Zhou, Shungui

2017-01-01

Lack of dissolved organic carbon (DOC) is generally one of the key factors limiting denitrification in subsoil beneath the root zone. Despite a number of laboratory DOC amendment studies, the effects of in situ DOC infiltration on subsoil denitrification, and on subsequent end product

Link between DOC in near surface peat and stream water in an upland catchment.

Science.gov (United States)

Clark, Joanna M; Lane, Stuart N; Chapman, Pippa J; Adamson, John K

2008-10-15

Hydrologic transport of dissolved organic carbon (DOC) from peat soils may differ to organo-mineral soils in how they responded to changes in flow, because of differences in soil profile and hydrology. In well-drained organo-mineral soils, low flow is through the lower mineral layer where DOC is absorbed and high flow is through the upper organic layer where DOC is produced. DOC concentrations in streams draining organo-mineral soils typically increase with flow. In saturated peat soils, both high and low flows are through an organic layer where DOC is produced. Therefore, DOC in stream water draining peat may not increase in response to changes in flow as there is no switch in flow path between a mineral and organic layer. To verify this, we conducted a high-resolution monitoring study of soil and stream water at an upland peat catchment in northern England. Our data showed a strong positive correlation between DOC concentrations at -1 and -5 cm depth and stream water, and weaker correlations between concentrations at -20 to -50 cm depth and stream water. Although near surface organic material appears to be the key source of stream water DOC in both peat and organo-mineral soils, we observed a negative correlation between stream flow and DOC concentrations instead of a positive correlation as DOC released from organic layers during low and high flow was diluted by rainfall. The differences in DOC transport processes between peat and organo-mineral soils have different implications for our understanding of long-term changes in DOC exports. While increased rainfall may cause an increase in DOC flux from peat due to an increase in water volume, it may cause a decrease in concentrations. This response is contrary to expected changes in DOC exports from organo-mineral soils, where increase rainfall is likely to result in an increase in flux and concentration.

Quantifying tropical peatland dissolved organic carbon (DOC) using UV-visible spectroscopy.

Science.gov (United States)

Cook, Sarah; Peacock, Mike; Evans, Chris D; Page, Susan E; Whelan, Mick J; Gauci, Vincent; Kho, Lip Khoon

2017-05-15

UV-visible spectroscopy has been shown to be a useful technique for determining dissolved organic carbon (DOC) concentrations. However, at present we are unaware of any studies in the literature that have investigated the suitability of this approach for tropical DOC water samples from any tropical peatlands, although some work has been performed in other tropical environments. We used water samples from two oil palm estates in Sarawak, Malaysia to: i) investigate the suitability of both single and two-wavelength proxies for tropical DOC determination; ii) develop a calibration dataset and set of parameters to calculate DOC concentrations indirectly; iii) provide tropical researchers with guidance on the best spectrophotometric approaches to use in future analyses of DOC. Both single and two-wavelength model approaches performed well with no one model significantly outperforming the other. The predictive ability of the models suggests that UV-visible spectroscopy is both a viable and low cost method for rapidly analyzing DOC in water samples immediately post-collection, which can be important when working at remote field sites with access to only basic laboratory facilities. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Vascular Plant and Vertebrate Inventory of Casa Grande Ruins National Monument

Science.gov (United States)

Powell, Brian F.; Albrecht, Eric W.; Schmidt, Cecilia A.; Halvorson, William L.; Anning, Pamela; Docherty, Kathleen

2006-01-01

Executive Summary This report summarizes results of the first comprehensive biological inventory of Casa Grande Ruins National Monument (NM) in southern Arizona. Surveys at the monument were part of a larger effort to inventory vascular plants and vertebrates in eight National Park Service units in Arizona and New Mexico. In 2001 and 2002 we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at Casa Grande Ruins NM to document the presence, and in some cases relative abundance, of species. By using repeatable study designs and standardized field techniques, which included quantified survey effort, we produced inventories that can serve as the basis for a biological monitoring program. Of the National Park Service units in the region, no other has experienced as much recent ecological change as Casa Grande Ruins NM. Once situated in a large and biologically diverse mesquite bosque near the perennially flowing Gila River, the monument is now a patch of sparse desert vegetation surrounded by urban and commercial development that is rapidly replacing agriculture as the dominant land use in the area. Roads, highways, and canals surround the monument. Development, and its associated impacts, has important implications for the plants and animals that live in the monument. The plant species list is small and the distribution and number of non-native plants appears to be increasing. Terrestrial vertebrates are also being impacted by the changing landscape, which is increasing the isolation of these populations from nearby natural areas and thereby reducing the number of species at the monument. These observations are alarming and are based on our review of previous studies, our research in the monument, and our knowledge of the biogeography and ecology of the Sonoran Desert. Together, these data suggest that the monument has lost a significant portion of its historic complement of species and these changes will likely intensify as

The conservation value of karst dolines for vascular plants in woodland habitats of Hungary: refugia and climate change

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Zoltán Bátori

2014-01-01

Full Text Available Limestone (karst surfaces in Hungary are rich in dolines, in which many endangered vascular plant species occur. To date, the majority of studies dealing with doline vegetation have focused on the local rather than the landscape level, without using comparative data from other areas. However, in this study we aimed to compare the vegetation pattern and species composition of dolines under different climate regimes of Hungary with regard to regional species pools. The fieldwork was carried out between 2005 and 2012. Twenty dolines were selected in the Mecsek Mountains (southern Hungary and nine dolines in the Aggtelek Karst area (northern Hungary. More than 900 vascular plants and more than 2000 plots were included in the study. The moving split window (MSW technique, nestedness analysis and principal coordinates analysis (PCoA were used to reveal the vegetation patterns in dolines. Although we found remarkable differences between the species composition of the two regions, dolines of both regions play a similar role in the preservation of different groups of species. Many plants, in particular mountain species, are restricted to the bottom of dolines where appropriate environmental conditions exist. In addition, depending on the doline geometry, many species of drier and warmer forests have colonized the upper slopes and rims. Thus, we can conclude that karst dolines of Hungary can be considered as reservoirs for many vascular plant species, therefore they are particularly important from a conservation point of view. Moreover, these dolines will likely become increasingly indispensable refugia for biodiversity under future global warming.

Convergent evolution of vascular optimization in kelp (Laminariales).

Science.gov (United States)

Drobnitch, Sarah Tepler; Jensen, Kaare H; Prentice, Paige; Pittermann, Jarmila

2015-10-07

Terrestrial plants and mammals, although separated by a great evolutionary distance, have each arrived at a highly conserved body plan in which universal allometric scaling relationships govern the anatomy of vascular networks and key functional metabolic traits. The universality of allometric scaling suggests that these phyla have each evolved an 'optimal' transport strategy that has been overwhelmingly adopted by extant species. To truly evaluate the dominance and universality of vascular optimization, however, it is critical to examine other, lesser-known, vascularized phyla. The brown algae (Phaeophyceae) are one such group--as distantly related to plants as mammals, they have convergently evolved a plant-like body plan and a specialized phloem-like transport network. To evaluate possible scaling and optimization in the kelp vascular system, we developed a model of optimized transport anatomy and tested it with measurements of the giant kelp, Macrocystis pyrifera, which is among the largest and most successful of macroalgae. We also evaluated three classical allometric relationships pertaining to plant vascular tissues with a diverse sampling of kelp species. Macrocystis pyrifera displays strong scaling relationships between all tested vascular parameters and agrees with our model; other species within the Laminariales display weak or inconsistent vascular allometries. The lack of universal scaling in the kelps and the presence of optimized transport anatomy in M. pyrifera raises important questions about the evolution of optimization and the possible competitive advantage conferred by optimized vascular systems to multicellular phyla. © 2015 The Author(s).

Vascular Plant and Vertebrate Inventory of Coronado National Memorial

Science.gov (United States)

Schmidt, Cecilia A.; Powell, Brian F.; Swann, Don E.; Halvorson, William L.

2007-01-01

We conducted inventories for amphibians and reptiles, birds, and mammals; and summarized past inventories for vascular plants at Coronado National Memorial (NM) in Arizona. We used our data as well as data from previous research to compile species lists for the memorial, assess inventory completeness, and make suggestions on future monitoring efforts. There have been 940 species of plants and vertebrates recorded at Coronado NM (Table 1), of which 46 (5%) are non-native. The species richness of the memorial is one of the highest in the Sonoran Desert Network of park units, third only to park units that are two and one-half (Chiricahua National Monument), 19 (Saguaro National Park) and 70 (Organ Pipe Cactus National Monument) times larger in area. The high species diversities are due to the large elevational gradient, overlap of bigeographical regions, wide range of geology and soils, and diverse vegetation communities present at the memorial. Changes in species composition have occurred at the memorial over the last 20 years in all major taxonomic groups. These changes are likely due to increases in grassy plant species (both native and non-native) at the lower elevations of the memorial. We suspect that grassy plant cover has increased because of changes in grazing intensity, introduction of some non-native species, and a recent fire. All recent vertebrate inventories have yielded grassland obligate species not previously recorded at the memorial. Based on the review of past studies, we believe the inventory for most taxa, except bats, is nearly complete, though some rare or elusive species will likely be added with additional survey effort.

DOC removal paradigms in highly humic aquatic ecosystems.

Science.gov (United States)

Farjalla, Vinicius F; Amado, André M; Suhett, Albert L; Meirelles-Pereira, Frederico

2009-07-01

Dissolved humic substances (HS) usually comprise 50-80% of the dissolved organic carbon (DOC) in aquatic ecosystems. From a trophic and biogeochemical perspective, HS has been considered to be highly refractory and is supposed to accumulate in the water. The upsurge of the microbial loop paradigm and the studies on HS photo-degradation into labile DOC gave rise to the belief that microbial processing of DOC should sustain aquatic food webs in humic waters. However, this has not been extensively supported by the literature, since most HS and their photo-products are often oxidized by microbes through respiration in most nutrient-poor humic waters. Here, we review basic concepts, classical studies, and recent data on bacterial and photo-degradation of DOC, comparing the rates of these processes in highly humic ecosystems and other aquatic ecosystems. We based our review on classical and recent findings from the fields of biogeochemistry and microbial ecology, highlighting some odd results from highly humic Brazilian tropical lagoons, which can reach up to 160 mg C L(-1). Highly humic tropical lagoons showed proportionally lower bacterial production rates and higher bacterial respiration rates (i.e., lower bacterial growth efficiency) than other lakes. Zooplankton showed similar delta(13)C to microalgae but not to humic DOC in these highly humic lagoons. Thus, the data reviewed here do not support the microbial loop as an efficient matter transfer pathway in highly humic ecosystems, where it is supposed to play its major role. In addition, we found that some tropical humic ecosystems presented the highest potential DOC photo-chemical mineralization (PM) rates reported in the literature, exceeding up to threefold the rates reported for temperate humic ecosystems. We propose that these atypically high PM rates are the result of a joint effect of the seasonal dynamics of allochthonous humic DOC input to these ecosystems and the high sunlight incidence throughout the year

[Characteristics of dissolved organic carbon release under inundation from typical grass plants in the water-level fluctuation zone of the Three Gorges Reservoir area].

Science.gov (United States)

Tan, Qiu-Xia; Zhu, Boi; Hua, Ke-Ke

2013-08-01

The water-level fluctuation zone of the Three Gorges Reservoir (TGR) exposes in spring and summer, then, green plants especially herbaceous plants grow vigorously. In the late of September, water-level fluctuation zone of TGR goes to inundation. Meanwhile, annually accumulated biomass of plant will be submerged for decaying, resulting in organism decomposition and release a large amount of dissolved organic carbon (DOC). This may lead to negative impacts on water environment of TGR. The typical herbaceous plants from water-level fluctuation zone were collected and inundated in the laboratory for dynamic measurements of DOC concentration of overlying water. According to the determination, the DOC release rates and fluxes have been calculated. Results showed that the release process of DOC variation fitted in a parabolic curve. The peak DOC concentrations emerge averagely in the 15th day of inundation, indicating that DOC released quickly with organism decay of herbaceous plant. The release process of DOC could be described by the logarithm equation. There are significant differences between the concentration of DOC (the maximum DOC concentration is 486.88 mg x L(-1) +/- 35.97 mg x L(-1) for Centaurea picris, the minimum is 4.18 mg x L(-1) +/- 1.07 mg x L(-1) for Echinochloacrus galli) and the release amount of DOC (the maximum is 50.54 mg x g(-1) for Centaurea picris, the minimum is 6.51 mg x g(-1) for Polygonum hydropiper) due to different characteristics of plants, especially, the values of C/N of herbaceous plants. The cumulative DOC release quantities during the whole inundation period were significantly correlated with plants' C/N values in linear equations.

Studies on distribution pattern of 14C-assimilates in relation to vascular pattern derived from phyllotaxis of tomato plants

International Nuclear Information System (INIS)

Shishido, Y.; Seyama, N.; Hori, Y.

1988-01-01

The association of distribution of photosynthetic assimilates in tomato with phyllotaxis and arrangement of the vascular system was studied. To ascertain the phyllotaxis of tomato plants, which was alternate with four orthostichies with devergence of 90° (270°) and 180°, the vascular system was revealed by methylene blue (0.5%), eothine (1.0%) and fuchsin (1.0%) from leaf petioles and the distribution of photosynthetic assmilates was measured by 14 C. The vascular system of tomato basically consisted of four orthostichies with two vascular bundles from each leaf. The arrangement of the vascular systems evidently affected the movement of 14 C-assimilates to sinks. Such movement from each leaf was affected by the degree of connection of the vascular bundles. Since tomato has a sympodial branching system, the leaf which is apparently situated just above the inflorescence differentiated before the inflorescence. The vascular bundles of the leaf of the sympodial branch around the inflorescence developed between the inflorescence and the leaf just above it. This results in a comparatively small proportion of distribution to the inflorescence from the leaf just above it

Modeling rates of DOC degradation using DOM composition and hydroclimatic variables

Science.gov (United States)

Moody, C. S.; Worrall, F.

2017-05-01

The fluvial fluxes of dissolved organic carbon (DOC) from peatlands form an important part of that ecosystem's carbon cycle, contributing approximately 35% of the overall peatland carbon budget. The in-stream processes acting on the DOC, such as photodegradation and biodegradation, can lead to DOC loss and thus contribute CO2 to the atmosphere. The aim of this study was to understand what controls the rates of DOC degradation. Water samples from a headwater, peat-covered catchment, were collected over a 23 month period and analyzed for the DOC degradation rate and dissolved organic matter (DOM) composition in the context of hydroclimatic monitoring. Measures of DOM composition included 13C solid-state nuclear magnetic resonance spectroscopy, bomb calorimetry, and elemental analysis. Regression analysis showed that there was a significant role for the composition of the DOM in controlling degradation with degradation rates significantly increasing with the proportion of aldehyde and carboxylic acid functional groups but decreasing with the proportion of N-alkyl functional groups. The highest rates of DOC degradation occurred when aldehyde functionality was at its greatest and this occurred on the recession limb of storm hydrographs. Including this knowledge into models of fluvial carbon fate for an 818 km2 catchment gave an annual average DOC removal rate of 67% and 50% for total organic carbon, slightly lower than previously predicted. The compositional controls suggest that DOM is primarily being used as a ready energy source to the aquatic ecosystem rather than as a nutrient source.

Modelling impacts of atmospheric deposition and temperature on long-term DOC trends.

Science.gov (United States)

Sawicka, K; Rowe, E C; Evans, C D; Monteith, D T; E I Vanguelova; Wade, A J; J M Clark

2017-02-01

It is increasingly recognised that widespread and substantial increases in Dissolved organic carbon (DOC) concentrations in remote surface, and soil, waters in recent decades are linked to declining acid deposition. Effects of rising pH and declining ionic strength on DOC solubility have been proposed as potential dominant mechanisms. However, since DOC in these systems is derived mainly from recently-fixed carbon, and since organic matter decomposition rates are considered sensitive to temperature, uncertainty persists over the extent to which other drivers that could influence DOC production. Such potential drivers include fertilisation by nitrogen (N) and global warming. We therefore ran the dynamic soil chemistry model MADOC for a range of UK soils, for which time series data are available, to consider the likely relative importance of decreased deposition of sulphate and chloride, accumulation of reactive N, and higher temperatures, on soil DOC production in different soils. Modelled patterns of DOC change generally agreed favourably with measurements collated over 10-20years, but differed markedly between sites. While the acidifying effect of sulphur deposition appeared to be the predominant control on the observed soil water DOC trends in all the soils considered other than a blanket peat, the model suggested that over the long term, the effects of nitrogen deposition on N-limited soils may have been sufficient to raise the "acid recovery DOC baseline" significantly. In contrast, reductions in non-marine chloride deposition and effects of long term warming appeared to have been relatively unimportant. The suggestion that future DOC concentrations might exceed preindustrial levels as a consequence of nitrogen pollution has important implications for drinking water catchment management and the setting and pursuit of appropriate restoration targets, but findings still require validation from reliable centennial-scale proxy records, such as those being developed

Vascular plant flora in the Cytadela cemeteries in Poznań (Poland

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Aneta Czarna

2016-12-01

Full Text Available The paper presents the spontaneous vascular flora and the flora originating from old or contemporary plantations found in all six currently existing cemeteries located in immediate vicinity on the slopes of the Cytadela Park in Poznań. These studies were carried out in the years 2011–2014. Over this period, 255 species of vascular plants were found. The most interesting species include: Chionodoxa luciliae, Rumex rugosus, Aegopodium podagraria ‘Variegatum’, Ficaria verna f. plenifolia, Galanthus nivalis f. pleniflora, Ornithogalum boucheanum, Ranunculus repens ‘Plena’, and hybrids: Dactylis ×intercedens, Gagea ×pomeranica, Ornithogalum boucheanum × O. nutans, Viola cyanea × V. odorata. A great number of spring geophytes, namely 31 species, was also found. Among species occurring spontaneously outside the graves, some were new for Poland, e.g., Chionodoxa luciliae, Ornithogalum boucheanum × O. nutans, Viola cyanea × V. odorata, while others were new for the Wielkopolska region: Rumex rugosus, Dactylis ×intercedens, Gagea ×pomeranica, as well as new for Poznań: Erigeron ramosus, Lilium bulbiferum, Muscari armeniacus, M. neglectum, Pimpinella nigra, Poa subcaerulea, and Veronica hederifolia s. s.

Photochemical mineralization of terrigenous DOC to dissolved inorganic carbon in ocean

OpenAIRE

Aarnos, Hanna; Gélinas, Yves; Kasurinen, Ville; Gu, Yufei; Puupponen, Veli-Mikko; Vähätalo, Anssi

2018-01-01

When terrigenous dissolved organic carbon (tDOC) rich in chromophoric dissolved organic matter (tCDOM) enters the ocean, solar radiation mineralizes it partially into dissolved inorganic carbon (DIC). This study addresses the amount and the rates of DIC photoproduction from tDOC and the area of ocean required to photomineralize tDOC. We collected water samples from 10 major rivers, mixed them with artificial seawater, and irradiated them with simulated solar radiation to measure DIC photoprod...

Floristic inventory of vascular plant in Nam Ha National Biodiversity Conservation Area, Lao People's Democratic Republic

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Jeong Ho Park

2018-06-01

Full Text Available The floristic inventory of vascular plants in Nam Ha National Biodiversity Conservation Area was conducted to understand the plant diversity in the northern area of Lao People's Democratic Republic. From the joint field surveys between Korean and Laos experts conducted during 2015–2017, it was found that there are 64 families, 145 genera, and 189 species distributed in the Nam Ba National Biodiversity Conservation Area, and a total of 56 families, 117 genera, and 148 species which comprise more than 78% of the total species were identified as endemic plants to the Lao People's Democratic Republic. Considering the usage of the plants, there are 91 species of medicinal plants, 33 species of ornamental plants, eight species of edible plants, and 16 species of economic plants. In addition, it was found out that Dalbergia balansae and Cinnamomum macrocarpum are categorized as vulnerable in the International Union for Conservation of Nature (IUCN Red list, and 13 more species are categorized as the least concern.

AR DOC: Augmented reality documentaries

DEFF Research Database (Denmark)

Vistisen, Peter

2014-01-01

Augmented Reality Documentaries (AR DOC) er et ’lille’ Shareplay projekt (ansøgte midler augmented reality cross media løsninger, til at skabe engagerende publikumsformidling...... indenfor oplevelsesindustrien. Projektet har genereret ny viden omkring, hvordan fysisk og digital formidling kan understøttes via Augmented Reality som formidlingsformat....

The evolution of development of vascular cambia and secondary growth

Science.gov (United States)

Andrew Groover; Rachel Spicer

2010-01-01

Secondary growth from vascular cambia results in radial, woody growth of stems. The innovation of secondary vascular development during plant evolution allowed the production of novel plant forms ranging from massive forest trees to flexible, woody lianas. We present examples of the extensive phylogenetic variation in secondary vascular growth and discuss current...

The effectiveness of arbuscular-mycorrhizal fungi and Aspergillus niger or Phanerochaete chrysosporium treated organic amendments from olive residues upon plant growth in a semi-arid degraded soil.

Science.gov (United States)

Medina, A; Roldán, A; Azcón, R

2010-12-01

Arbuscular mycorrhizal (AM) fungi and a residue from dry olive cake (DOC) supplemented with rock phosphate (RP) and treated with either Aspergillus niger (DOC-A) or Phanerochaete chrysosporium (DOC-P), were assayed in a natural, semi-arid soil using Trifolium repens or Dorycnium pentaphyllum plants. The effects of the AM fungi and/or DOC-A were compared with P-fertilisation (P) over eleven successive harvests to evaluate the persistence of the effectiveness of the treatments. The biomass of dually-treated plants after four successive harvests was greater than that obtained for non-treated plants or those receiving the AM inoculum or DOC-A treatments after eleven yields. The AM inoculation was critical for obtaining plant growth benefit from the application of fermented DOC-A residue. The abilities of the treatments to prevent plant drought stress were also assayed. Drought-alleviating effects were evaluated in terms of plant growth, proline and total sugars concentration under alternative drought and re-watering conditions (8th and 9th harvests). The concentrations of both compounds in plant biomass increased under drought when DOC-A amendment and AM inoculation were employed together: they reinforced the plant drought-avoidance capabilities and anti-oxidative defence. Water stress was less compensated in P-fertilised than in DOC-A-treated plants. DOC-P increased D. pentaphyllum biomass, shoot P content, nodule number and AM colonisation, indicating the greater DOC-transforming ability of P. chrysosporium compared to A. niger. The lack of AM colonisation and nodulation in this soil was compensated by the application of DOC-P, particularly with AM inoculum. The management of natural resources (organic amendments and soil microorganisms) represents an important strategy that assured the growth, nutrition and plant establishment in arid, degraded soils, preventing the damage that arises from limited water and nutrient supply. Copyright © 2010 Elsevier Ltd. All rights

G-DOC Plus - an integrative bioinformatics platform for precision medicine.

Science.gov (United States)

Bhuvaneshwar, Krithika; Belouali, Anas; Singh, Varun; Johnson, Robert M; Song, Lei; Alaoui, Adil; Harris, Michael A; Clarke, Robert; Weiner, Louis M; Gusev, Yuriy; Madhavan, Subha

2016-04-30

G-DOC Plus is a data integration and bioinformatics platform that uses cloud computing and other advanced computational tools to handle a variety of biomedical BIG DATA including gene expression arrays, NGS and medical images so that they can be analyzed in the full context of other omics and clinical information. G-DOC Plus currently holds data from over 10,000 patients selected from private and public resources including Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA) and the recently added datasets from REpository for Molecular BRAin Neoplasia DaTa (REMBRANDT), caArray studies of lung and colon cancer, ImmPort and the 1000 genomes data sets. The system allows researchers to explore clinical-omic data one sample at a time, as a cohort of samples; or at the level of population, providing the user with a comprehensive view of the data. G-DOC Plus tools have been leveraged in cancer and non-cancer studies for hypothesis generation and validation; biomarker discovery and multi-omics analysis, to explore somatic mutations and cancer MRI images; as well as for training and graduate education in bioinformatics, data and computational sciences. Several of these use cases are described in this paper to demonstrate its multifaceted usability. G-DOC Plus can be used to support a variety of user groups in multiple domains to enable hypothesis generation for precision medicine research. The long-term vision of G-DOC Plus is to extend this translational bioinformatics platform to stay current with emerging omics technologies and analysis methods to continue supporting novel hypothesis generation, analysis and validation for integrative biomedical research. By integrating several aspects of the disease and exposing various data elements, such as outpatient lab workup, pathology, radiology, current treatments, molecular signatures and expected outcomes over a web interface, G-DOC Plus will continue to strengthen precision medicine research. G-DOC Plus is available

Cavitation Resistance in Seedless Vascular Plants: The Structure and Function of Interconduit Pit Membranes1[W][OPEN

Science.gov (United States)

Brodersen, Craig; Jansen, Steven; Choat, Brendan; Rico, Christopher; Pittermann, Jarmila

2014-01-01

Plant water transport occurs through interconnected xylem conduits that are separated by partially digested regions in the cell wall known as pit membranes. These structures have a dual function. Their porous construction facilitates water movement between conduits while limiting the spread of air that may enter the conduits and render them dysfunctional during a drought. Pit membranes have been well studied in woody plants, but very little is known about their function in more ancient lineages such as seedless vascular plants. Here, we examine the relationships between conduit air seeding, pit hydraulic resistance, and pit anatomy in 10 species of ferns (pteridophytes) and two lycophytes. Air seeding pressures ranged from 0.8 ± 0.15 MPa (mean ± sd) in the hydric fern Athyrium filix-femina to 4.9 ± 0.94 MPa in Psilotum nudum, an epiphytic species. Notably, a positive correlation was found between conduit pit area and vulnerability to air seeding, suggesting that the rare-pit hypothesis explains air seeding in early-diverging lineages much as it does in many angiosperms. Pit area resistance was variable but averaged 54.6 MPa s m−1 across all surveyed pteridophytes. End walls contributed 52% to the overall transport resistance, similar to the 56% in angiosperm vessels and 64% in conifer tracheids. Taken together, our data imply that, irrespective of phylogenetic placement, selection acted on transport efficiency in seedless vascular plants and woody plants in equal measure by compensating for shorter conduits in tracheid-bearing plants with more permeable pit membranes. PMID:24777347

Evaluation of Dissolved Inorganic and Organic Carbon Concentrations (DIC, DOC and Their Isotopic Compositions (δ 13C-DOC, δ 13C-DIC in Water Resources of the Karde Catchment (North of Mashhad

Directory of Open Access Journals (Sweden)

Hossein Mohammadzadeh

2015-07-01

Full Text Available In this paper, the variations of dissolved inorganic and organic carbon (DIC, DOC concentrations and their isotopic compositions (δ13C- DIC, δ13C- DOC were evaluated in both surface and ground water resources in the Karde catchment area (with an area of about 547 Km2, located in the North of Mashhad. To identify the sources of the dissolved carbon (DIC and DOC, samples were collected in June 2011 from surface and ground water resources (river, dam’s lake, springs, wells, and Qanat and from depths of 1, 5, 10, 15, and 20 meters of Karde dam lakeat a point located near the dam outlet. Field parameters (T, EC, and TDS were measured during sampling. All measurements were performed in the G.G. Hatch Stable Isotope Laboratory at the University of Ottawa, Canada. The concentrations and isotopic compositions of DIC and DOC were determined using TCA and CF-IRMS instruments, respectively. Based on the results obt 1-دانشیار،مرکزتحقیقاتآبهایزیرزمینی متآب،دانشکدهعلوم،دانشگاهفردوسی مشهد،،مشهد، ایران 2- دانشجوی کارشناسی ارشدهیدروژئولوژی، مرکزتحقیقاتآبهایزیرزمینی متآب،دانشکده علوم،دانشگاهفردوسیمشهد، مشهد، ایران *نویسنده مسئول، پست الکترونیکی:mohammadzadeh@um.ac.ir           ained, the average values of DIC are 54.1 mg/l and 66.8 mg/l in the surface and ground water resources in the Karde catchment area, respectively; the average values of DOC are 2.2 mg/l and 0.45 mg/l; the average values of δ13C-DIC are -7‰ and -11 ‰; and the average values of δ13C-DOC are -31.6‰ and -29.5 ‰, respectively. In general, the concentrations of DIC, DOC, and their isotopic compositions (δ13C-DIC, δ13C-DOC are different in the various water resources (surface and ground water in the catchment and the major source of dissolved carbon in the catchment area is

The Root-Associated Microbial Community of the World's Highest Growing Vascular Plants.

Science.gov (United States)

Angel, Roey; Conrad, Ralf; Dvorsky, Miroslav; Kopecky, Martin; Kotilínek, Milan; Hiiesalu, Inga; Schweingruber, Fritz; Doležal, Jiří

2016-08-01

Upward migration of plants to barren subnival areas is occurring worldwide due to raising ambient temperatures and glacial recession. In summer 2012, the presence of six vascular plants, growing in a single patch, was recorded at an unprecedented elevation of 6150 m.a.s.l. close to the summit of Mount Shukule II in the Western Himalayas (Ladakh, India). Whilst showing multiple signs of stress, all plants have managed to establish stable growth and persist for several years. To learn about the role of microbes in the process of plant upward migration, we analysed the root-associated microbial community of the plants (three individuals from each) using microscopy and tagged amplicon sequencing. No mycorrhizae were found on the roots, implying they are of little importance to the establishment and early growth of the plants. However, all roots were associated with a complex bacterial community, with richness and diversity estimates similar or even higher than the surrounding bare soil. Both soil and root-associated communities were dominated by members of the orders Sphingomonadales and Sphingobacteriales, which are typical for hot desert soils, but were different from communities of temperate subnival soils and typical rhizosphere communities. Despite taxonomic similarity on the order level, the plants harboured a unique set of highly dominant operational taxonomic units which were not found in the bare soil. These bacteria have been likely transported with the dispersing seeds and became part of the root-associated community following germination. The results indicate that developing soils act not only as a source of inoculation to plant roots but also possibly as a sink for plant-associated bacteria.

Taxonomic and phylogenetic diversity of vascular plants at Ma'anling volcano urban park in tropical Haikou, China: Reponses to soil properties.

Science.gov (United States)

Cheng, Xia-Lan; Yuan, Lang-Xing; Nizamani, Mir Mohammad; Zhu, Zhi-Xin; Friedman, Cynthia Ross; Wang, Hua-Feng

2018-01-01

Anthropogenic processes and socio-economic factors play important roles in shaping plant diversity in urban parks. To investigate how plant diversity of Ma' anling urban volcano park in Hainan Province, China respond to these factors, we carried out a field investigation on the taxonomic and phylogenetic diversity of vascular plants and soil properties in this area. We found 284 species of vascular plants belonging to 88 families and 241 genera, which included 194 native species, 23 invasive species, 31 naturalized species, 40 cultivars, and 4 rare / endangered plant species. Tree composition and richness significantly varied between different vegetation formations (plantation, secondary forest, and abandoned land). Plant species richness and community composition were significantly affected by elevation (El), soil water content (WC), total soil nitrogen (TN) and soil organic matter (SOM). There were significant diversity differences between plantations and abandoned lands, but not between the plantations and secondary forests. The flora in the study site was tropical in nature, characterized by pantropic distributions. Compared to adjacent areas, floristic composition in the study site was most similar to that of Guangdong, followed by that of Vietnam. Our study revealed the diversity patterns of volcanic plants and provided the basis for future planning of plant conservation, such as preserving plant species, maintaining plant habitats, and coordinating plant management in this region.

78 FR 66892 - BASF Plant Science LP; Availability of Plant Pest Risk Assessment and Environmental Assessment...

Science.gov (United States)

2013-11-07

.... Kevin Shea, Administrator, Animal and Plant Health Inspection Service. [FR Doc. 2013-26701 Filed 11-6-13... DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service [Docket No. APHIS-2012-0028] BASF Plant Science LP; Availability of Plant Pest Risk Assessment and Environmental Assessment for...

Relationship between the shoot characteristics and plant resistance to vascular-streak dieback on cocoa

Directory of Open Access Journals (Sweden)

Agung Wahyu Soesilo

2014-12-01

Full Text Available Vascular-streak dieback (Oncobasidium theobromae is a serious disease on cocoa damaging the vegetative tissue especially on the branches and leaves. This research was aimed to identify the relationship between characteristics of sprouting ability and VSD resistance to confirm the response of cocoa to pruning treatment on VSD control and developing criteria for selection. Trial was carried out at Kaliwining Experimental Station of ICCRI, a VSD-endemic area by using 668 plants of hybrid populayion which were derivated from intercrossing among seven clones performing different response to VSD. The resistance was evaluated by scoring the plant damage with the scale of 0-6 on drought season in the year of 2009 and 2011. The characteristics of sprouting ability was assessed by recording the pruned trees for the variables of the number of re-growth shoot, shoot height, number of new shoot per pruned branches, shoot diameter and number of leaves per shoot. It was analyzed that the variables of the number of shoot per pruned branches, shoot diameter, shoot height and number of leaves per shoot were not significantly correlated to the score of VSD damage. Grouping of the resistance also performed similar results whereas mean of the sprouting variables were not different among group but the percentage of sprouted branches tend to be higher with the higher of the resistance (lower score. This result confirmed any mechanism of tolerance on VSD resistance by accelerating shoot rejuvenation on resistant plant. Key words : vascular-streak diaback, cocoa, resistance, characteristics of sprouting

Application of vascular aquatic plants for pollution removal, energy and food production in a biological system

Science.gov (United States)

Wolverton, B. C.; Barlow, R. M.; Mcdonald, R. C.

1975-01-01

Vascular aquatic plants such as water hyacinths (Eichhornia crassipes) (Mart.) Solms and alligator weeds (Alternanthera philoxeroides) (Mart.) Griesb., when utilized in a controlled biological system (including a regular program of harvesting to achieve maximum growth and pollution removal efficiency), may represent a remarkably efficient and inexpensive filtration and disposal system for toxic materials and sewage released into waters near urban and industrial areas. The harvested and processed plant materials are sources of energy, fertilizer, animal feed, and human food. Such a system has industrial, municipal, and agricultural applications.

75 FR 12496 - Proposed Information Collection; Comment Request; DOC National Environmental Policy Act...

Science.gov (United States)

2010-03-16

...; DOC National Environmental Policy Act Environmental Questionnaire and Checklist AGENCY: Office of the...., Washington, DC 20230 (or via the Internet at [email protected]doc.gov ). FOR FURTHER INFORMATION CONTACT: Requests for... Constitution Avenue, NW., Washington, DC 20230 (or via the Internet at [email protected]doc.gov ). SUPPLEMENTARY...

Do oxygen stable isotopes track precipitation moisture source in vascular plant dominated peatlands?

Science.gov (United States)

Charman, D.; Amesbury, M. J.; Newnham, R.; Loader, N.; Goodrich, J. P.; Gallego-Sala, A. V.; Royles, J.; Keller, E. D.; Baisden, W. T.

2014-12-01

Variations in the isotopic composition of precipitation are determined by fractionation processes which occur during temperature and humidity dependent phase changes associated with evaporation and condensation. Oxygen stable isotope ratios have therefore been frequently used as a source of palaeoclimate data from a variety of proxy archives. Exploitation of this record from ombrotrophic peatlands, where the source water used in cellulose synthesis is derived solely from precipitation, has been mostly limited to Northern Hemisphere Sphagnum-dominated bogs, with limited application in the Southern Hemisphere (SH) or in peatlands dominated by vascular plants. Throughout New Zealand (NZ), the preserved root matrix of the restionaceous wire rush (Empodisma spp.) forms deep peat deposits. NZ provides an ideal location to undertake empirical research into oxygen isotope fractionation in vascular peatlands because sites are ideally suited to single taxon analysis, preserve potentially high resolution full Holocene palaeoclimate records and are situated in the climatically sensitive SH mid-latitudes. Crucially, large gradients exist in the mean isotopic composition of precipitation across NZ, caused primarily by the relative influence of different climate modes. We test the capacity for δ18O analysis of Empodisma alpha cellulose from ombrotrophic restiad peatlands in NZ to provide a methodology for developing palaeoclimate records. We took surface plant, water and precipitation samples over spatial (six sites spanning >10° latitude) and temporal (monthly measurements over one year) gradients. We found a strong link between the isotopic compositions of surface root water, the most likely source water for plant growth, and precipitation in both datasets. Back-trajectory modelling of precipitation moisture source for rain days prior to sampling showed clear seasonality in the temporal data that was reflected in surface root water. The link between source water and plant

Quantification of dissolved organic carbon (DOC) storage in lakes and reservoirs of mainland China.

Science.gov (United States)

Song, Kaishan; Wen, Zhidan; Shang, Yingxing; Yang, Hong; Lyu, Lili; Liu, Ge; Fang, Chong; Du, Jia; Zhao, Ying

2018-04-04

As a major fraction of carbon in inland waters, dissolved organic carbon (DOC) plays a crucial role in carbon cycling on a global scale. However, the quantity of DOC stored in lakes and reservoirs was not clear to date. In an attempt to examine the factors that determine the DOC storage in lakes and reservoirs across China, we assembled a large database (measured 367 lakes, and meta-analyzed 102 lakes from five limnetic regions; measured 144 reservoirs, and meta-analyzed 272 reservoirs from 31 provincial units) of DOC concentrations and water storages for lakes and reservoirs that are used to determine DOC storage in static inland waters. We found that DOC concentrations in saline waters (Mean/median ± S.D: 50.5/30.0 ± 55.97 mg/L) are much higher than those in fresh waters (8.1/5.9 ± 6.8 mg/L), while lake DOC concentrations (25.9/11.5 ± 42.04 mg/L) are much higher than those in reservoirs (5.0/3.8 ± 4.5 mg/L). In terms of lake water volume and DOC storage, the Tibet-Qinghai lake region has the largest water volume (552.8 km 3 ), 92% of which is saline waters, thus the largest DOC (13.39 Tg) is stored in these alpine lake region; followed by the Mengxin lake region, having a water volume of 99.4 km 3 in which 1.75 Tg DOC was stored. Compared to Mengxin lake region, almost the same amount of water was stored in East China lake region (91.9 km 3 ), however, much less DOC was stored in this region (0.43 Tg) due to the lower DOC concentration (Ave: 3.45 ± 2.68 mg/L). According to our investigation, Yungui and Northeast lake regions had water storages of 32.14 km 3 and 19.44 km 3 respectively, but relatively less DOC was stored in Yungui (0.13 Tg) than in Northeast lake region (0.19 Tg). Due to low DOC concentration in reservoirs, especially these large reservoirs having lower DOC concentration (V > 1.0 km 3 : 2.31 ± 1.48 mg/L), only 1.54 Tg was stored in a 485.1 km 3 volume of water contained

Implications of the degree of controllability of controlled plants in the sense of LQR optimal control

Science.gov (United States)

Xia, Yaping; Yin, Minghui; Zou, Yun

2018-01-01

In this paper, the relationship between the degree of controllability (DOC) of controlled plants and the corresponding quadratic optimal performance index in LQR control is investigated for the electro-hydraulic synchronising servo control systems and wind turbine systems, respectively. It is shown that for these two types of systems, the higher the DOC of a controlled plant is, the better the quadratic optimal performance index is. It implies that in some LQR controller designs, the measure of the DOC of a controlled plant can be used as an index for the optimisation of adjustable plant parameters, by which the plant can be controlled more effectively.

Studies on distribution pattern of {sup 14}C-assimilates in relation to vascular pattern derived from phyllotaxis of tomato plants

Energy Technology Data Exchange (ETDEWEB)

Shishido, Y. [National Research Inst. of Vegetables, Ornamental Plants and Tea, Ano, Mie (Japan); Seyama, N.; Hori, Y.

1988-12-15

The association of distribution of photosynthetic assimilates in tomato with phyllotaxis and arrangement of the vascular system was studied. To ascertain the phyllotaxis of tomato plants, which was alternate with four orthostichies with devergence of 90° (270°) and 180°, the vascular system was revealed by methylene blue (0.5%), eothine (1.0%) and fuchsin (1.0%) from leaf petioles and the distribution of photosynthetic assmilates was measured by {sup 14}C. The vascular system of tomato basically consisted of four orthostichies with two vascular bundles from each leaf. The arrangement of the vascular systems evidently affected the movement of {sup 14}C-assimilates to sinks. Such movement from each leaf was affected by the degree of connection of the vascular bundles. Since tomato has a sympodial branching system, the leaf which is apparently situated just above the inflorescence differentiated before the inflorescence. The vascular bundles of the leaf of the sympodial branch around the inflorescence developed between the inflorescence and the leaf just above it. This results in a comparatively small proportion of distribution to the inflorescence from the leaf just above it.

Convergent evolution of vascular optimization in kelp (Laminariales)

DEFF Research Database (Denmark)

Drobnitch, Sarah Tepler; Jensen, Kaare Hartvig; Prentice, Paige

2015-01-01

Terrestrial plants and mammals, although separated by a great evolutionary distance, have each arrived at a highly conserved body plan in which universal allometric scaling relationships govern the anatomy of vascular networks and key functional metabolic traits. The universality of allometric...... (Phaeophyceae) are one such group—as distantly related to plants as mammals, they have convergently evolved a plant-like body plan and a specialized phloem-like transport network. To evaluate possible scaling and optimization in the kelp vascular system, we developed a model of optimized transport anatomy...... and tested it with measurements of the giant kelp, Macrocystis pyrifera, which is among the largest and most successful of macroalgae. We also evaluated three classical allometric relationships pertaining to plant vascular tissues with a diverse sampling of kelp species. Macrocystis pyrifera displays strong...

Music interventions in disorders of consciousness (DOC) - a systematic review.

Science.gov (United States)

Grimm, Teresa; Kreutz, Gunter

2018-03-22

The effects of music interventions including active and receptive music therapy for people living with neurogenic disorders of consciousness (DOC) have been subject to empirical studies in the past. The aim of this systematic review was to find and analyse the current research about the effects of musical interventions on people with DOC. For this purpose, studies with music interventions and patients with DOC from the year 1900 to 2017 were searched in English, German, and French in different databases. Risk-of-bias-analyses were conducted for each study that fulfilled the inclusion criteria. Twenty-two quantitative studies (three randomised controlled trials with more than 10 participants) were found eligible for review. They include a total of 329 participants living with either coma, unresponsive wakefulness syndrome, or minimally conscious state. Music interventions were associated with favourable behavioural and physiological responses in several studies, but methodological quality and outcomes were heterogeneous. More studies with a larger number of participants are needed as well as a consensus on key characteristics of effective short-term and long-term music interventions for DOC.

Vascular Plant and Vertebrate Inventory of Tuzigoot National Monument

Science.gov (United States)

Powell, Brian F.; Albrecht, E.W.; Halvorson, William Lee; Schmidt, Cecilia A.; Anning, P.; Docherty, K.

2005-01-01

Executive Summary From 2002 to 2004, we surveyed for plants and vertebrates (amphibians, reptiles, birds, and mammals) at Tuzigoot National Monument (NM) and adjacent areas in Arizona. This was the first effort of its kind in the area and was part of a larger effort to inventory vascular plants and vertebrates in eight National Park Service units in Arizona and New Mexico. In addition to our own surveys, we also compiled a complete list of species that have been found by previous studies. We found 330 species, including 142 that had not previously been recorded at the monument (Table 1). We found 39 species of non-native plants, 11 non-native fishes, three non-native birds, and one non-native species each of amphibian and mammal. Based on our work and that of others, there have been 597 species of plants and vertebrates found at the monument. The bird community at the monument had the highest species richness of any national park unit in central and southern Arizona. We found all other taxa to have intermediate species richness compared to other park units in the region. This extraordinary species richness observed for birds, as well as for some other taxa, is due primarily to Tavasci Marsh and the Verde River, two critical sources of perennial water, which provide habitat for many regionally rare or uncommon species. The location of the monument at the northern edge of the Sonoran Desert and at the southern edge of the Mogollon Rim also plays an important role in determining the distribution and community composition of the plant and vertebrate communities. Based on our findings, we believe the high number of non-native species, especially fish and plants, should be of particular management concern. We detail other management challenges, most notably the rapid increase in housing and associated commercial development near the monument, which will continue to impact the plant and vertebrate communities. Based on our data and a review of past studies, we believe the

Insertional mutagenesis in the vascular wilt pathogen Verticillium dahliae

NARCIS (Netherlands)

Santhanam, P.

2014-01-01

Vascular wilt diseases caused by soil-borne pathogens are among the most

devastating plant diseases worldwide. The ascomycete fungus Verticillium dahliae

causes vascular wilt diseases in hundreds of dicotyledonous plant species, including

important crops such as eggplant,

Nonlinear and threshold-dominated runoff generation controls DOC export in a small peat catchment

Science.gov (United States)

Birkel, C.; Broder, T.; Biester, H.

2017-03-01

We used a relatively simple two-layer, coupled hydrology-biogeochemistry model to simultaneously simulate streamflow and stream dissolved organic carbon (DOC) concentrations in a small lead and arsenic contaminated upland peat catchment in northwestern Germany. The model procedure was informed by an initial data mining analysis, in combination with regression relationships of discharge, DOC, and element export. We assessed the internal model DOC processing based on stream DOC hysteresis patterns and 3-hourly time step groundwater level and soil DOC data for two consecutive summer periods in 2013 and 2014. The parsimonious model (i.e., few calibrated parameters) showed the importance of nonlinear and rapid near-surface runoff generation mechanisms that caused around 60% of simulated DOC load. The total load was high even though these pathways were only activated during storm events on average 30% of the monitoring time—as also shown by the experimental data. Overall, the drier period 2013 resulted in increased nonlinearity but exported less DOC (115 kg C ha-1 yr-1 ± 11 kg C ha-1 yr-1) compared to the equivalent but wetter period in 2014 (189 kg C ha-1 yr-1 ± 38 kg C ha-1 yr-1). The exceedance of a critical water table threshold (-10 cm) triggered a rapid near-surface runoff response with associated higher DOC transport connecting all available DOC pools and subsequent dilution. We conclude that the combination of detailed experimental work with relatively simple, coupled hydrology-biogeochemistry models not only allowed the model to be internally constrained but also provided important insight into how DOC and tightly coupled pollutants or trace elements are mobilized.

Extraordinary slow degradation of dissolved organic carbon (DOC) in a cold marginal sea.

Science.gov (United States)

Kim, Tae-Hoon; Kim, Guebuem; Lee, Shin-Ah; Dittmar, Thorsten

2015-09-08

Dissolved organic carbon (DOC) is the largest organic carbon reservoir in the ocean, and the amount of carbon in this reservoir rivals that in atmospheric CO2. In general, DOC introduced into the deep ocean undergoes a significant degradation over a centennial time scale (i.e., ~50 μM to ~34 μM in the North Atlantic and Mediterranean Sea). However, we here show that high concentrations of DOC (58 ± 4 μM) are maintained almost constantly over 100 years in the entire deep East/Japan Sea (EJS). The degradation rate in this sea is estimated to be 0.04 μmol C kg(-1) yr(-1), which is 2-3 times lower than that in the North Atlantic and Mediterranean Sea. Since the source of DOC in the deep EJS is found to be of marine origin on the basis of δ(13)C-DOC signatures, this slow degradation rate seems to be due to low temperature (DOC in the world ocean is very sensitive to global warming and slowdown of global deep-water overturning.

Linear-motion tattoo machine and prefabricated needle sets for the delivery of plant viruses by vascular puncture inoculation

Science.gov (United States)

Vascular puncture inoculation (VPI) of plant viruses previously has been conducted either manually or by use of a commercial engraving tool and laboratory-fabricated needle arrays. In an effort to improve this technique, a linear-motion tattoo machine driving industry-standard needle arrays was tes...

Ethnobotany of food plants in the high river Ter valley (Pyrenees, Catalonia, Iberian Peninsula): non-crop food vascular plants and crop food plants with medicinal properties.

Science.gov (United States)

Rigat, Montse; Bonet, Maria Àngels; Garcia, Sònia; Garnatje, Teresa; Vallès, Joan

2009-01-01

The present study reports a part of the findings of an ethnobotanical research project conducted in the Catalan region of the high river Ter valley (Iberian Peninsula), concerning the use of wild vascular plants as food and the medicinal uses of both wild and cultivated food plants. We have detected 100 species which are or have been consumed in this region, 83 of which are treated here (the remaining are the cultivated food plants without additional medicinal uses). Some of them, such as Achillea ptarmica subsp. pyrenaica, Convolvulus arvensis, Leontodon hispidus, Molopospermum peloponnesiacum and Taraxacum dissectum, have not been previously reported, or have only very rarely been cited or indicated as plant foods in very restricted geographical areas. Several of these edible wild plants have a therapeutic use attributed to them by local people, making them a kind of functional food. They are usually eaten raw, dressed in salads or cooked; the elaboration of products from these species such as liquors or marmalades is a common practice in the region. The consumption of these resources is still fairly alive in popular practice, as is the existence of homegardens, where many of these plants are cultivated for private consumption.

Using herbarium-derived DNAs to assemble a large-scale DNA barcode library for the vascular plants of Canada.

Science.gov (United States)

Kuzmina, Maria L; Braukmann, Thomas W A; Fazekas, Aron J; Graham, Sean W; Dewaard, Stephanie L; Rodrigues, Anuar; Bennett, Bruce A; Dickinson, Timothy A; Saarela, Jeffery M; Catling, Paul M; Newmaster, Steven G; Percy, Diana M; Fenneman, Erin; Lauron-Moreau, Aurélien; Ford, Bruce; Gillespie, Lynn; Subramanyam, Ragupathy; Whitton, Jeannette; Jennings, Linda; Metsger, Deborah; Warne, Connor P; Brown, Allison; Sears, Elizabeth; Dewaard, Jeremy R; Zakharov, Evgeny V; Hebert, Paul D N

2017-12-01

Constructing complete, accurate plant DNA barcode reference libraries can be logistically challenging for large-scale floras. Here we demonstrate the promise and challenges of using herbarium collections for building a DNA barcode reference library for the vascular plant flora of Canada. Our study examined 20,816 specimens representing 5076 of 5190 vascular plant species in Canada (98%). For 98% of the specimens, at least one of the DNA barcode regions was recovered from the plastid loci rbcL and matK and from the nuclear ITS2 region. We used beta regression to quantify the effects of age, type of preservation, and taxonomic affiliation (family) on DNA sequence recovery. Specimen age and method of preservation had significant effects on sequence recovery for all markers, but influenced some families more (e.g., Boraginaceae) than others (e.g., Asteraceae). Our DNA barcode library represents an unparalleled resource for metagenomic and ecological genetic research working on temperate and arctic biomes. An observed decline in sequence recovery with specimen age may be associated with poor primer matches, intragenomic variation (for ITS2), or inhibitory secondary compounds in some taxa.

DOC:NO3- ratios and NO3- uptake in forested headwater streams

Science.gov (United States)

Rodríguez-Cardona, Bianca; Wymore, Adam S.; McDowell, William H.

2016-01-01

The underlying mechanisms driving the coupled interactions between inorganic nitrogen uptake and dissolved organic matter are not well understood, particularly in surface waters. To determine the relationship between dissolved organic carbon (DOC) quantity and nitrate (NO3-) uptake kinetics in streams, we performed a series of NO3- Tracer Additions for Spiraling Curve Characterization experiments in four streams within the Lamprey River Watershed, New Hampshire, across a range in background DOC concentrations (1-8 mg C/L). Experiments were performed throughout the 2013 and 2014 growing seasons. Across streams and experimental dates, ambient uptake velocity (Vf) correlated positively with increasing DOC concentrations and DOC:NO3- ratios but was only weakly negatively associated with NO3- concentrations. Ambient NO3- Vf was unrelated to pH, light, temperature, dissolved oxygen, and Specific Ultraviolet Absorbance at 254 nm. Although there were general tendencies across the entire Lamprey River Watershed, individual sites behaved differently in their uptake kinetics. NO3- uptake dynamics in the Lamprey River Watershed are most strongly influenced by DOC concentrations rather than NO3- concentrations or physicochemical parameters, which have been identified as regional- to continental-scale drivers in previous research. Understanding the fundamental relationships between dissolved organic matter and inorganic nutrients will be important as global and climatic changes influence the delivery and production of DOC and NO3- in aquatic ecosystems.

Compiled data on the vascular aquatic plant program, 1975 - 1977. [for sewage lagoon

Science.gov (United States)

Wolverton, B. C.; Mcdonald, R.

1977-01-01

The performance of a single cell, facultative sewage lagoon was significantly improved with the introduction of vascular aquatic plants. Water hyacinth (Eichhornia crassipes) was the dominant plant from April to November; duckweed (Lemna spp.) and (Spirodela spp.) flourished from December to March. This 2 ha lagoon received approximately 475 cu m/day of untreated sewage and has a variable COD sub 5 loading rate of 22-30 kg/ha/day. During the first 14 months of operation with aquatic plants, the average influent BOD sub 5 was reduced by 95% from 110 mg/l to an average of 5 mg/l in the effluent. The average influent suspended solids were reduced by 90% from 97 mg/l to 10 mg/l in the effluent. Significant reductions in nitrogen and phosphorus were effected. The monthly kjeldahl nitrogen for influent and effluent averaged 12.0 and 3.4 mg/l, respectively, a reduction of 72%. The total phosphorus was reduced on an average of 56% from 3.7 mg/l influent to 1.6 mg/l effluent.

Testing seasonal and long-term controls of streamwater DOC using empirical and process-based models.

Science.gov (United States)

Futter, Martyn N; de Wit, Heleen A

2008-12-15

Concentrations of dissolved organic carbon (DOC) in surface waters are increasing across Europe and parts of North America. Several mechanisms have been proposed to explain these increases including reductions in acid deposition, change in frequency of winter storms and changes in temperature and precipitation patterns. We used two modelling approaches to identify the mechanisms responsible for changing surface water DOC concentrations. Empirical regression analysis and INCA-C, a process-based model of stream-water DOC, were used to simulate long-term (1986--2003) patterns in stream water DOC concentrations in a small boreal stream. Both modelling approaches successfully simulated seasonal and inter-annual patterns in DOC concentration. In both models, seasonal patterns of DOC concentration were controlled by hydrology and inter-annual patterns were explained by climatic variation. There was a non-linear relationship between warmer summer temperatures and INCA-C predicted DOC. Only the empirical model was able to satisfactorily simulate the observed long-term increase in DOC. The observed long-term trends in DOC are likely to be driven by in-soil processes controlled by SO4(2-) and Cl(-) deposition, and to a lesser extent by temperature-controlled processes. Given the projected changes in climate and deposition, future modelling and experimental research should focus on the possible effects of soil temperature and moisture on organic carbon production, sorption and desorption rates, and chemical controls on organic matter solubility.

14CO2 labeling. A reliable technique for rapid measurement of total root exudation capacity and vascular sap flow in crop plants

International Nuclear Information System (INIS)

Bhupinder Singh; Sumedha Ahuja; Renu Pandey; Singhal, R.K.

2014-01-01

Root release of organic compounds and rate of the vascular sap flow are important for understanding the nutrient and the source-sink dynamics in plants, however, their determination is procedurally cumbersome and time consuming. We report here a simple method involving 14 C labeling for rapid and reliable measurement of root exudates and vascular sap flow rate in a variable groundnut population developed through seed gamma irradiation using a cobalt source ( 60 Co). An experimental hypothesis that a higher 14 C level in the vascular sap would indicate a higher root release of carbon by the roots into the rhizosphere was verified. (author)

Traditional ecological knowledge among Sami reindeer herders in northern Sweden about vascular plants grazed by reindeer

Directory of Open Access Journals (Sweden)

Berit Inga

2013-03-01

Full Text Available Traditional knowledge about how reindeer utilize forage resources was expected to be crucial to reindeer herders. Seventeen Sami reindeer herders in four reindeer herding communities in Sweden (“samebyar” in Swedish were interviewed about plants species considered to be important reindeer food plants in scientific literature. Among 40 plant species, which the informants were asked to identify and indicate whether and when they were grazed by reindeer, they identified a total of 21 plant taxa and five plant groups. They especially recognised species that were used as human food by the Sami themselves, but certain specific forage plants were also identified. Detailed knowledge of vascular plants at the species level was surprisingly general, which may indicate that knowledge of pasture resources in a detailed species level is not of vital importance. This fact is in sharp contradiction to the detailed knowledge that Sami people express for example about reindeer (as an animal or snow (as physical element. The plausible explanation is that observations of individual plant species are unnecessarily detailed information in large-scale reindeer pastoralism, because the animals graze freely under loose herding and border surveillance.

Doc2b synchronizes secretion from chromaffin cells by stimulating fast and inhibiting sustained release

DEFF Research Database (Denmark)

da Silva Pinheiro, Paulo César; de Wit, Heidi; Walter, Alexander M

2013-01-01

Synaptotagmin-1 and -7 constitute the main calcium sensors mediating SNARE-dependent exocytosis in mouse chromaffin cells, but the role of a closely related calcium-binding protein, Doc2b, remains enigmatic. We investigated its role in chromaffin cells using Doc2b knock-out mice and high temporal...... resolution measurements of exocytosis. We found that the calcium dependence of vesicle priming and release triggering remained unchanged, ruling out an obligatory role for Doc2b in those processes. However, in the absence of Doc2b, release was shifted from the readily releasable pool to the subsequent...... sustained component. Conversely, upon overexpression of Doc2b, the sustained component was largely inhibited whereas the readily releasable pool was augmented. Electron microscopy revealed an increase in the total number of vesicles upon Doc2b overexpression, ruling out vesicle depletion as the cause...

Purification and crystallization of Phd, the antitoxin of the phd/doc operon

International Nuclear Information System (INIS)

Garcia-Pino, Abel; Sterckx, Yann; Vandenbussche, Guy; Loris, Remy

2010-01-01

The antitoxin Phd from the phd/doc operon of bacteriophage P1 was crystallized in two distinct crystal forms. The antitoxin Phd from the phd/doc module of bacteriophage P1 was crystallized in two distinct crystal forms. Crystals of His-tagged Phd contain a C-terminally truncated version of the protein and diffract to 2.20 Å resolution. Crystals of untagged Phd purified from the Phd–Doc complex diffract to 2.25 Å resolution. These crystals are partially merohedrally twinned and contain the full-length version of the protein

[Variation of water DOC during the process of pre-pressure and coagulation sedimentation treatment].

Science.gov (United States)

Chen, Wen-Jing; Cong, Hai-Bing; Xu, Ya-Jun; Wang, Wei; Jiang, Xin-Yue; Liu, Yu-Jiao

2014-07-01

The aim of the study was to explore whether the pre-pressure and coagulation sedimentation process would result in algal cell disruption, leading to increased dissolved organic carbon (DOC) in water, based on which, the pressure application mode would be optimized and safe and efficient pre-pressure algae removal process would be obtained. The changes in DOC during the process of pre-pressure and preoxidation treatment, the distribution of molecular weight in water as well as the removal efficiency of algae, turbidity and DOC after coagulation and sedimentation were investigated. The results showed that the DOC in water did not increase but decreased, and the molecular weight decreased after treated with 0.5-0.8 MPa pressure. While KMnO4 and NaClO pre-oxidation both increased the DOC, in the meanwhile, the distribution of molecular weight showed no obvious change. After the pre-pressure coagulation and sedimentation process, the removal rate of algae was 96.23% and that of DOC was 29. 11%, which was by 10% - 30% higher than the rate of pre-oxidation coagulation and sedimentation process.

Tourism and recreation listed as a threat for a wide diversity of vascular plants: a continental scale review.

Science.gov (United States)

Rankin, Benjamin Luke; Ballantyne, Mark; Pickering, Catherine Marina

2015-05-01

Tourism and recreation are diverse and popular activities. They may also contribute to the risk of extinction for some plants because of the range and severity of their impacts, including in protected areas: but which species, where and how? To evaluate the extent to which tourism and recreation may be threatening process for plants, we conducted a continental level review of listed threats to endangered vascular plants using data from Australia. Of the 659 vascular plant species listed as critically endangered or endangered by the Australian Government, tourism and recreation were listed as a threat(s) for 42%. This is more than those listed as threatened by climate change (26%) and close to the proportion listed as threatened by altered fire regimes (47%). There are plant species with tourism and recreation listed threats in all States and Territories and from all but one bioregion in Australia. Although more than 45 plant families have species with tourism and recreation listed as threats, orchids were the most common species listed as at risk from these threats (90 species). The most common types of threats listed were visitors collecting plants in protected areas (113 species), trampling by hikers and others (84 species), damage from recreational vehicles (59 species) and road infrastructure (39 species). Despite the frequency with which tourism and recreation were listed as threats in Australia, research quantifying these threats and methods to ameliorate their impacts are still limited. Although this lack of information contributes to the challenge of managing tourism and recreation, impacts from visitors will often be easier to manage within natural areas than those from larger scale threats such as altered fire regimes and climate change. Copyright © 2015 Elsevier Ltd. All rights reserved.

NOM characterization and removal at six Southern African water treatment plants

Directory of Open Access Journals (Sweden)

J. Haarhoff

2010-04-01

Full Text Available Organic pollution is a major concern during drinking water treatment. Major challenges attributed to organic pollution include the proliferation of pathogenic micro-organisms, prevalence of toxic and physiologically disruptive organic micro-pollutants, and quality deterioration in water distribution systems. A major component of organic pollution is natural organic matter (NOM. The operational mechanisms of most unit processes are well understood. However, their interaction with NOM is still the subject of scientific research. This paper takes the form of a meta-study to capture some of the experiences with NOM monitoring and analysis at a number of Southern African Water Treatment Plants. It is written from the perspective of practical process selection, to try and coax some pointers from the available data for the design of more detailed pilot work. NOM was tracked at six water treatment plants using dissolved organic carbon (DOC measurements. Fractionation of the DOC based on biodegradability and molecular weight distribution was done at a water treatment plant in Namibia. A third fractionation technique using ion exchange resins was used to assess the impact of ozonation on DOC. DOC measurements alone did not give much insight into NOM evolution through the treatment train. The more detailed characterization techniques showed that different unit processes preferentially remove different NOM fractions. Therefore these techniques provide better information for process design and optimisation than the DOC measurement which is routinely done during full scale operation at these water treatment plants.

The "Martian" flora: new collections of vascular plants, lichens, fungi, algae, and cyanobacteria from the Mars Desert Research Station, Utah

Science.gov (United States)

Freebury, Colin E.; Hamilton, Paul B.; Saarela, Jeffery M.

2016-01-01

Abstract The Mars Desert Research Station is a Mars analog research site located in the desert outside of Hanksville, Utah, U.S.A. Here we present a preliminary checklist of the vascular plant and lichen flora for the station, based on collections made primarily during a two-week simulated Mars mission in November, 2014. Additionally, we present notes on the endolithic chlorophytes and cyanobacteria, and the identification of a fungal genus also based on these collections. Altogether, we recorded 38 vascular plant species from 14 families, 13 lichen species from seven families, six algae taxa including both chlorophytes and cyanobacteria, and one fungal genus from the station and surrounding area. We discuss this floristic diversity in the context of the ecology of the nearby San Rafael Swell and the desert areas of Wayne and Emery counties in southeastern Utah. PMID:27350765

Vascular development of the grapevine (Vitis vinifera L.) inflorescence rachis in response to flower number, plant growth regulators and defoliation.

Science.gov (United States)

Gourieroux, Aude M; Holzapfel, Bruno P; McCully, Margaret E; Scollary, Geoffrey R; Rogiers, Suzy Y

2017-09-01

The grapevine inflorescence is a determinate panicle and as buds emerge, shoot, flower and rachis development occur simultaneously. The growth and architecture of the rachis is determined by genetic and environmental factors but here we examined the role of flower and leaf number as well as hormones on its elongation and vascular development. The consequences of rachis morphology and vascular area on berry size and composition were also assessed. One week prior to anthesis, Merlot and Cabernet Sauvignon field vines were exposed to manual flower removal, exogenous plant growth regulators or pre-bloom leaf removal. Manual removal of half the flowers along the vertical axis of the inflorescence resulted in a shorter rachis in both cultivars. Conversely, inflorescences treated with gibberellic acid (GA 3 ) and the synthetic cytokinin, 6-benzylaminopurine (BAP) resulted in a longer rachis while pre-bloom removal of all leaves on the inflorescence-bearing shoot did not alter rachis length relative to untreated inflorescences. Across the treatments, the cross-sectional areas of the conducting xylem and phloem in the rachis were positively correlated to rachis girth, flower number at anthesis, bunch berry number, bunch berry fresh mass and bunch sugar content at harvest. Conversely, average berry size and sugar content were not linked to rachis vascular area. These data indicate that the morphological and vascular development of the rachis was more responsive to flower number and plant growth regulators than to leaf removal.

Regulation of plant vascular stem cells by endodermis-derived EPFL-family peptide hormones and phloem-expressed ERECTA-family receptor kinases.

Science.gov (United States)

Uchida, Naoyuki; Tasaka, Masao

2013-12-01

Plant vasculatures are complex tissues consisting of (pro)cambium, phloem, and xylem. The (pro)cambium serves as vascular stem cells that produce all vascular cells. The Arabidopsis ERECTA (ER) receptor kinase is known to regulate the architecture of inflorescence stems. It was recently reported that the er mutation enhances a vascular phenotype induced by a mutation of TDR/PXY, which plays a significant role in procambial proliferation, suggesting that ER participates in vascular development. However, detailed molecular mechanisms of the ER-dependent vascular regulation are largely unknown. Here, this work found that ER and its paralogue, ER-LIKE1, were redundantly involved in procambial development of inflorescence stems. Interestingly, their activity in the phloem was sufficient for vascular regulation. Furthermore, two endodermis-derived peptide hormones, EPFL4 and EPFL6, were redundantly involved in such regulation. It has been previously reported that EPFL4 and EPFL6 act as ligands of phloem-expressed ER for stem elongation. Therefore, these findings indicate that cell-cell communication between the endodermis and the phloem plays an important role in procambial development as well as stem elongation. Interestingly, similar EPFL-ER modules control two distinct developmental events by slightly changing their components: the EPFL4/6-ER module for stem elongation and the EPFL4/6-ER/ERL1 module for vascular development.

Using herbarium-derived DNAs to assemble a large-scale DNA barcode library for the vascular plants of Canada1

Science.gov (United States)

Kuzmina, Maria L.; Braukmann, Thomas W. A.; Fazekas, Aron J.; Graham, Sean W.; Dewaard, Stephanie L.; Rodrigues, Anuar; Bennett, Bruce A.; Dickinson, Timothy A.; Saarela, Jeffery M.; Catling, Paul M.; Newmaster, Steven G.; Percy, Diana M.; Fenneman, Erin; Lauron-Moreau, Aurélien; Ford, Bruce; Gillespie, Lynn; Subramanyam, Ragupathy; Whitton, Jeannette; Jennings, Linda; Metsger, Deborah; Warne, Connor P.; Brown, Allison; Sears, Elizabeth; Dewaard, Jeremy R.; Zakharov, Evgeny V.; Hebert, Paul D. N.

2017-01-01

Premise of the study: Constructing complete, accurate plant DNA barcode reference libraries can be logistically challenging for large-scale floras. Here we demonstrate the promise and challenges of using herbarium collections for building a DNA barcode reference library for the vascular plant flora of Canada. Methods: Our study examined 20,816 specimens representing 5076 of 5190 vascular plant species in Canada (98%). For 98% of the specimens, at least one of the DNA barcode regions was recovered from the plastid loci rbcL and matK and from the nuclear ITS2 region. We used beta regression to quantify the effects of age, type of preservation, and taxonomic affiliation (family) on DNA sequence recovery. Results: Specimen age and method of preservation had significant effects on sequence recovery for all markers, but influenced some families more (e.g., Boraginaceae) than others (e.g., Asteraceae). Discussion: Our DNA barcode library represents an unparalleled resource for metagenomic and ecological genetic research working on temperate and arctic biomes. An observed decline in sequence recovery with specimen age may be associated with poor primer matches, intragenomic variation (for ITS2), or inhibitory secondary compounds in some taxa. PMID:29299394

Fifty-five new records of vascular plants, and other discoveries for the flora of Santa Catarina, southern Brazil

DEFF Research Database (Denmark)

Funez, Luís A.; Hassemer, Gustavo; Ferreira, João Paulo R.

2017-01-01

The flora of Santa Catarina is the best known in Brazil, and yet considerable knowledge gaps remain. Aiming at filling these gaps, we present here 55 new records of vascular plants for this Brazilian state, and the re-collection of four species after more than 50 years. About 50% of new records...

COLWRIT – Collaborative Online Writing in Google Docs

DEFF Research Database (Denmark)

Andreasen, Lars Birch; Winther, Frederikke; Hanghøj, Thorkild

2014-01-01

The poster presents preliminary hypotheses and findings of an on-going research project at Aalborg University, Denmark, which explores university students’ uses of collaborative writing tools like Google Docs when doing collaborative project work. The research project has a special focus on the v......The poster presents preliminary hypotheses and findings of an on-going research project at Aalborg University, Denmark, which explores university students’ uses of collaborative writing tools like Google Docs when doing collaborative project work. The research project has a special focus...... on the various effects on the collaboration process of students’ various usage of the commenting functions of online writing tools. The poster received the Best Poster Award at the conference....

48 CFR 1337.110-71 - Additional DOC clauses related to service contracting.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Additional DOC clauses related to service contracting. 1337.110-71 Section 1337.110-71 Federal Acquisition Regulations System....110-71 Additional DOC clauses related to service contracting. (a) Insert a clause substantially...

Modelling impacts of atmospheric deposition and temperature on long-term DOC trends

NARCIS (Netherlands)

Sawicka, Kasia; Rowe, E.C.; Evans, C.D.; Monteith, D.T.; Vanguelova, E.I.; Wade, A.J.; Clark, J.M.

2017-01-01

It is increasingly recognised that widespread and substantial increases in Dissolved organic carbon (DOC) concentrations in remote surface, and soil, waters in recent decades are linked to declining acid deposition. Effects of rising pH and declining ionic strength on DOC solubility have been

The Vascular Pathogen Verticillium longisporum Does Not Affect Water Relations and Plant Responses to Drought Stress of Its Host, Brassica napus.

Science.gov (United States)

Lopisso, Daniel Teshome; Knüfer, Jessica; Koopmann, Birger; von Tiedemann, Andreas

2017-04-01

Verticillium longisporum is a host-specific vascular pathogen of oilseed rape (Brassica napus L.) that causes economic crop losses by impairing plant growth and inducing premature senescence. This study investigates whether plant damage through Verticillium stem striping is due to impaired plant water relations, whether V. longisporum affects responses of a susceptible B. napus variety to drought stress, and whether drought stress, in turn, affects plant responses to V. longisporum. Two-factorial experiments on a susceptible cultivar of B. napus infected or noninfected with V. longisporum and exposed to three watering levels (30, 60, and 100% field capacity) revealed that drought stress and V. longisporum impaired plant growth by entirely different mechanisms. Although both stresses similarly affected plant growth parameters (plant height, hypocotyl diameter, and shoot and root dry matter), infection of B. napus with V. longisporum did not affect any drought-related physiological or molecular genetic plant parameters, including transpiration rate, stomatal conductance, photosynthesis rate, water use efficiency, relative leaf water content, leaf proline content, or the expression of drought-responsive genes. Thus, this study provides comprehensive physiological and molecular genetic evidence explaining the lack of wilt symptoms in B. napus infected with V. longisporum. Likewise, drought tolerance of B. napus was unaffected by V. longisporum, as was the level of disease by drought conditions, thus excluding a concerted action of both stresses in the field. Although it is evident that drought and vascular infection with V. longisporum impair plant growth by different mechanisms, it remains to be determined by which other factors V. longisporum causes crop loss.

Process Inference from High Frequency Temporal Variations in Dissolved Organic Carbon (DOC) Dynamics Across Nested Spatial Scales

Science.gov (United States)

Tunaley, C.; Tetzlaff, D.; Lessels, J. S.; Soulsby, C.

2014-12-01

In order to understand aquatic ecosystem functioning it is critical to understand the processes that control the spatial and temporal variations in DOC. DOC concentrations are highly dynamic, however, our understanding at short, high frequency timescales is still limited. Optical sensors which act as a proxy for DOC provide the opportunity to investigate near-continuous DOC variations in order to understand the hydrological and biogeochemical processes that control concentrations at short temporal scales. Here we present inferred 15 minute stream water DOC data for a 12 month period at three nested scales (1km2, 3km2 and 31km2) for the Bruntland Burn, a headwater catchment in NE Scotland. High frequency data were measured using FDOM and CDOM probes which work by measuring the fluorescent component and coloured component, respectively, of DOC when exposed to ultraviolet light. Both FDOM and CDOM were strongly correlated (r2 >0.8) with DOC allowing high frequency estimations. Results show the close coupling of DOC with discharge throughout the sampling period at all three spatial scales. However, analysis at the event scale highlights anticlockwise hysteresis relationships between DOC and discharge due to the delay in DOC being flushed from the increasingly large areas of peaty soils as saturation zones expand and increase hydrological connectivity. Lag times vary between events dependent on antecedent conditions. During a 10 year drought period in late summer 2013 it was apparent that very small changes in discharge on a 15 minute timescale result in high increases in DOC. This suggests transport limitation during this period where DOC builds up in the soil and is not flushed regularly, therefore any subsequent increase in discharge results in large DOC peaks. The high frequency sensors also reveal diurnal variability during summer months related to the photo-oxidation, evaporative and biological influences of DOC during the day. This relationship is less

Natural diet of coral-excavating sponges consists mainly of dissolved organic carbon (DOC).

Science.gov (United States)

Mueller, Benjamin; de Goeij, Jasper M; Vermeij, Mark J A; Mulders, Yannick; van der Ent, Esther; Ribes, Marta; van Duyl, Fleur C

2014-01-01

Coral-excavating sponges are the most important bioeroders on Caribbean reefs and increase in abundance throughout the region. This increase is commonly attributed to a concomitant increase in food availability due to eutrophication and pollution. We therefore investigated the uptake of organic matter by the two coral-excavating sponges Siphonodictyon sp. and Cliona delitrix and tested whether they are capable of consuming dissolved organic carbon (DOC) as part of their diet. A device for simultaneous sampling of water inhaled and exhaled by the sponges was used to directly measure the removal of DOC and bacteria in situ. During a single passage through their filtration system 14% and 13% respectively of the total organic carbon (TOC) in the inhaled water was removed by the sponges. 82% (Siphonodictyon sp.; mean ± SD; 13 ± 17 μmol L(-1)) and 76% (C. delitrix; 10 ± 12 μmol L(-1)) of the carbon removed was taken up in form of DOC, whereas the remainder was taken up in the form of particulate organic carbon (POC; bacteria and phytoplankton) despite high bacteria retention efficiency (72 ± 15% and 87 ± 10%). Siphonodictyon sp. and C. delitrix removed DOC at a rate of 461 ± 773 and 354 ± 562 μmol C h(-1) respectively. Bacteria removal was 1.8 ± 0.9 × 10(10) and 1.7 ± 0.6 × 10(10) cells h(-1), which equals a carbon uptake of 46.0 ± 21.2 and 42.5 ± 14.0 μmol C h(-1) respectively. Therefore, DOC represents 83 and 81% of the TOC taken up by Siphonodictyon sp. and C. delitrix per hour. These findings suggest that similar to various reef sponges coral-excavating sponges also mainly rely on DOC to meet their carbon demand. We hypothesize that excavating sponges may also benefit from an increasing production of more labile algal-derived DOC (as compared to coral-derived DOC) on reefs as a result of the ongoing coral-algal phase shift.

Natural diet of coral-excavating sponges consists mainly of dissolved organic carbon (DOC.

Directory of Open Access Journals (Sweden)

Benjamin Mueller

Full Text Available Coral-excavating sponges are the most important bioeroders on Caribbean reefs and increase in abundance throughout the region. This increase is commonly attributed to a concomitant increase in food availability due to eutrophication and pollution. We therefore investigated the uptake of organic matter by the two coral-excavating sponges Siphonodictyon sp. and Cliona delitrix and tested whether they are capable of consuming dissolved organic carbon (DOC as part of their diet. A device for simultaneous sampling of water inhaled and exhaled by the sponges was used to directly measure the removal of DOC and bacteria in situ. During a single passage through their filtration system 14% and 13% respectively of the total organic carbon (TOC in the inhaled water was removed by the sponges. 82% (Siphonodictyon sp.; mean ± SD; 13 ± 17 μmol L(-1 and 76% (C. delitrix; 10 ± 12 μmol L(-1 of the carbon removed was taken up in form of DOC, whereas the remainder was taken up in the form of particulate organic carbon (POC; bacteria and phytoplankton despite high bacteria retention efficiency (72 ± 15% and 87 ± 10%. Siphonodictyon sp. and C. delitrix removed DOC at a rate of 461 ± 773 and 354 ± 562 μmol C h(-1 respectively. Bacteria removal was 1.8 ± 0.9 × 10(10 and 1.7 ± 0.6 × 10(10 cells h(-1, which equals a carbon uptake of 46.0 ± 21.2 and 42.5 ± 14.0 μmol C h(-1 respectively. Therefore, DOC represents 83 and 81% of the TOC taken up by Siphonodictyon sp. and C. delitrix per hour. These findings suggest that similar to various reef sponges coral-excavating sponges also mainly rely on DOC to meet their carbon demand. We hypothesize that excavating sponges may also benefit from an increasing production of more labile algal-derived DOC (as compared to coral-derived DOC on reefs as a result of the ongoing coral-algal phase shift.

Vascular Plant and Vertebrate Inventory of Tumacacori National Historical Park

Science.gov (United States)

Powell, Brian F.; Albrecht, Eric W.; Halvorson, William L.; Schmidt, Cecilia A.; Anning, Pamela; Docherty, Kathleen

2005-01-01

Executive Summary This report summarizes the results of the first comprehensive biological inventory of Tumacacori National Historical Park (NHP) in southern Arizona. These surveys were part of a larger effort to inventory vascular plants and vertebrates in eight National Park Service units in Arizona and New Mexico. From 2000 to 2003 we surveyed for vascular plants and vertebrates (fish, amphibians, reptiles, birds, and mammals) at Tumacacori NHP to document presence of species within the administrative boundaries of the park's three units. Because we used repeatable study designs and standardized field techniques, these inventories can serve as the first step in a long-term monitoring program. We recorded 591 species at Tumacacori NHP, significantly increasing the number of known species for the park (Table 1). Species of note in each taxonomic group include: * Plants: second record in Arizona of muster John Henry, a non-native species that is ranked a 'Class A noxious weed' in California; * Amphibian: Great Plains narrow-mouthed toad; * Reptiles: eastern fence lizard and Sonoran mud turtle; * Birds: yellow-billed cuckoo, green kingfisher, and one observation of the endangered southwestern willow flycatcher; * Fishes: four native species including an important population of the endangered Gila topminnow in the Tumacacori Channel; * Mammals: black bear and all four species of skunk known to occur in Arizona. We recorded 79 non-native species (Table E.S.1), many of which are of management concern, including: Bermudagrass, tamarisk, western mosquitofish, largemouth bass, bluegill, sunfish, American bullfrog, feral cats and dogs, and cattle. We also noted an abundance of crayfish (a non-native invertebrate). We review some of the important non-native species and make recommendations to remove them or to minimize their impacts on the native biota of the park. Based on the observed species richness, Tumacacori NHP possesses high biological diversity of plants, fish

The Intrinsically Disordered Domain of the Antitoxin Phd Chaperones the Toxin Doc against Irreversible Inactivation and Misfolding*

Science.gov (United States)

De Gieter, Steven; Konijnenberg, Albert; Talavera, Ariel; Butterer, Annika; Haesaerts, Sarah; De Greve, Henri; Sobott, Frank; Loris, Remy; Garcia-Pino, Abel

2014-01-01

The toxin Doc from the phd/doc toxin-antitoxin module targets the cellular translation machinery and is inhibited by its antitoxin partner Phd. Here we show that Phd also functions as a chaperone, keeping Doc in an active, correctly folded conformation. In the absence of Phd, Doc exists in a relatively expanded state that is prone to dimerization through domain swapping with its active site loop acting as hinge region. The domain-swapped dimer is not capable of arresting protein synthesis in vitro, whereas the Doc monomer is. Upon binding to Phd, Doc becomes more compact and is secured in its monomeric state with a neutralized active site. PMID:25326388

ToxicDocs (www.ToxicDocs.org): from history buried in stacks of paper to open, searchable archives online.

Science.gov (United States)

Rosner, David; Markowitz, Gerald; Chowkwanyun, Merlin

2018-02-01

As a result of a legal mechanism called discovery, the authors accumulated millions of internal corporate and trade association documents related to the introduction of new products and chemicals into workplaces and commerce. What did these private entities discuss among themselves and with their experts? The plethora of documents, both a blessing and a curse, opened new sources and interesting questions about corporate and regulatory histories. But they also posed an almost insurmountable challenge to historians. Thus emerged ToxicDocs, possible only with a technological innovation known as "Big Data." That refers to the sheer volume of new digital data and to the computational power to analyze them. Users will be able to identify what firms knew (or did not know) about the dangers of toxic substances in their products-and when. The database opens many areas to inquiry including environmental studies, business history, government regulation, and public policy. ToxicDocs will remain a resource free and open to all, anywhere in the world.

Vascular plants promote ancient peatland carbon loss with climate warming.

Science.gov (United States)

Walker, Tom N; Garnett, Mark H; Ward, Susan E; Oakley, Simon; Bardgett, Richard D; Ostle, Nicholas J

2016-05-01

Northern peatlands have accumulated one third of the Earth's soil carbon stock since the last Ice Age. Rapid warming across northern biomes threatens to accelerate rates of peatland ecosystem respiration. Despite compensatory increases in net primary production, greater ecosystem respiration could signal the release of ancient, century- to millennia-old carbon from the peatland organic matter stock. Warming has already been shown to promote ancient peatland carbon release, but, despite the key role of vegetation in carbon dynamics, little is known about how plants influence the source of peatland ecosystem respiration. Here, we address this issue using in situ (14)C measurements of ecosystem respiration on an established peatland warming and vegetation manipulation experiment. Results show that warming of approximately 1 °C promotes respiration of ancient peatland carbon (up to 2100 years old) when dwarf-shrubs or graminoids are present, an effect not observed when only bryophytes are present. We demonstrate that warming likely promotes ancient peatland carbon release via its control over organic inputs from vascular plants. Our findings suggest that dwarf-shrubs and graminoids prime microbial decomposition of previously 'locked-up' organic matter from potentially deep in the peat profile, facilitating liberation of ancient carbon as CO2. Furthermore, such plant-induced peat respiration could contribute up to 40% of ecosystem CO2 emissions. If consistent across other subarctic and arctic ecosystems, this represents a considerable fraction of ecosystem respiration that is currently not acknowledged by global carbon cycle models. Ultimately, greater contribution of ancient carbon to ecosystem respiration may signal the loss of a previously stable peatland carbon pool, creating potential feedbacks to future climate change. © 2016 John Wiley & Sons Ltd.

Vascular Plant and Vertebrate Inventory of Tonto National Monument

Science.gov (United States)

Albrecht, Eric W.; Powell, Brian F.; Halvorson, William L.; Schmidt, Cecilia A.

2007-01-01

This report summarizes the results of the first biological inventory of plants and vertebrates at Tonto National Monument (NM). From 2001 to 2003, we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at Tonto NM to record species presence. We focused most of our efforts along the Cave Springs riparian area, but surveyed other areas as well. We recorded 149 species in the riparian area, and 369 species overall in the monument, including 65 plant species and four bird species that were previously unrecorded for the monument. We recorded 78 plant species in the riparian area that previous studies had not indicated were present there. Several species of each taxonomic group were found only in the riparian area, suggesting that because of their concentration in this small area these populations are vulnerable to disturbance and may be of management concern. Four of the bird species that we recorded (Bell's vireo, yellow warbler, summer tanager, and Abert's towhee) have been identified as riparian 'obligate' species by other sources. Bird species that are obligated to riparian areas are targets of conservation concern due to widespread degradation of riparian areas in the desert southwest over the last century. The flora and fauna of the riparian area would benefit from continued limited public access. The dependence of the riparian area on the spring and surface flow suggests monitoring of this resource per se would benefit management of the riparian area's flora and fauna as well. The monument would benefit from incorporating monitoring protocols developed by the Sonoran Desert Network Inventory and Monitoring program rather than initiating a separate program for the riparian area. Park managers can encourage the Inventory and Monitoring program to address the unique monitoring challenges presented by small spatial areas such as this riparian area, and can request specific monitoring recommendations. We suggest that repeat

[Estimation of DOC concentrations using CDOM absorption coefficients: a case study in Taihu Lake].

Science.gov (United States)

Jiang, Guang-Jia; Ma, Rong-Hua; Duan, Hong-Tao

2012-07-01

Dissolved organic carbon (DOC) is the largest organic carbon stock in water ecosystems, which plays an important role in the carbon cycle in water. Chromophoric dissolved organic matter (CDOM), an important water color variation, is the colored fraction of DOC and its absorption controls the instruction of light under water. The available linkage between DOC concentration and CDOM absorptions enables the determination of DOC accumulations using remote sensing reflectance or radiance in lake waters. The present study explored the multi-liner relationship between CDOM absorptions [a(g) (250) and a(g) (365)] and DOC concentrations in Taihu Lake, based on the available data in 4 cruises (201005, 201101, 201103, 201105) (totally 183 sampling sites). Meanwhile, the results were validated with the data of the experiment carried out from August 29 to September 2, 2011 in Taihu Lake (n = 27). Furthermore, a universal pattern of modeling from remote sensing was built for lake waters. The results demonstrated that this method provided more satisfying estimation of DOC concentrations in Taihu Lake. Except the data obtained in January 2011, the fitted results of which were not conductive to the winter dataset (201101) in Taihu Lake, due to the diverse sources and sinks of DOC and CDOM, the multi-liner relationship was robust for the data collected in the other three cruises (R2 = 0.64, RMSE = 14.31%, n = 164), which was validated using the 201108 sampling dataset (R2 = 0.67, RMSE = 10.58%, n = 27). In addition, the form of the statistic model is universal, to some extent, for other water areas, however, there is difference in the modeling coefficients. Further research should be focused on the parameterization using local data from different lakes, which provides effective methodology for the estimation of DOC concentrations in lakes and other water regions.

Implementing Gmail Docs and Blogs for Enhancing Motivation towards Writing in English

Science.gov (United States)

Gomez Zapata, Julian Esteban

2010-01-01

This action research paper dealt with how to increase motivation towards writing in English through blogs and Gmail docs in a private school in Medellín, Colombia. It was necessary to explore the concepts of "social interaction," "motivation" and "reasons for writing" to understand how blogs and Gmail docs favored…

System requirements and design description for the document basis database interface (DocBasis)

International Nuclear Information System (INIS)

Lehman, W.J.

1997-01-01

This document describes system requirements and the design description for the Document Basis Database Interface (DocBasis). The DocBasis application is used to manage procedures used within the tank farms. The application maintains information in a small database to track the document basis for a procedure, as well as the current version/modification level and the basis for the procedure. The basis for each procedure is substantiated by Administrative, Technical, Procedural, and Regulatory requirements. The DocBasis user interface was developed by Science Applications International Corporation (SAIC)

Radiocarbon in marine dissolved organic carbon (DOC)

NARCIS (Netherlands)

Clercq, M. le; Plicht, J. van der; Meijer, H.A.J.; Baar, H.J.W. de

Dissolved Organic Carbon (DOC) plays an important role in the ecology and carbon cycle in the ocean. Analytical problems with concentration and isotope ratio measurements have hindered its study. We have constructed a new analytical method based on supercritical oxidation for the determination of

Herbarium of vascular plants collection of the university of extremadura (Spain).

Science.gov (United States)

Espinosa, Marta; López, Josefa

2013-01-01

The herbarium of University of Extremadura (UNEX Herbarium) is formed by 36451 specimens of vascular plants whose main origin is the autonomous region of Extremadura (Spain) and Portugal, although it also contains a smaller number of specimens from different places, including the rest of peninsular Spain, the Baleares Islands, the Macaronesian region (Canary Islands, Madeira and Azores), northwest of Africa (Morocco) and Brazil. 98% of the total records are georeferenced. It is an active collection in continuous growth. Its data can be accessed through the GBIF data portal at http://data.gbif.org/datasets/resource/255 and http://www.eweb.unex.es/eweb/botanica/herbario/. This paper describes the specimen associated data set of the UNEX Herbarium, with an objective to disseminate the data contained in a data set with potential users, and promote the multiple uses of the data.

Revisiting the origin and diversification of vascular plants through a comprehensive Bayesian analysis of the fossil record.

Science.gov (United States)

Silvestro, Daniele; Cascales-Miñana, Borja; Bacon, Christine D; Antonelli, Alexandre

2015-07-01

Plants have a long evolutionary history, during which mass extinction events dramatically affected Earth's ecosystems and its biodiversity. The fossil record can shed light on the diversification dynamics of plant life and reveal how changes in the origination-extinction balance have contributed to shaping the current flora. We use a novel Bayesian approach to estimate origination and extinction rates in plants throughout their history. We focus on the effect of the 'Big Five' mass extinctions and on estimating the timing of origin of vascular plants, seed plants and angiosperms. Our analyses show that plant diversification is characterized by several shifts in origination and extinction rates, often matching the most important geological boundaries. The estimated origin of major plant clades predates the oldest macrofossils when considering the uncertainties associated with the fossil record and the preservation process. Our findings show that the commonly recognized mass extinctions have affected each plant group differently and that phases of high extinction often coincided with major floral turnovers. For instance, after the Cretaceous-Paleogene boundary we infer negligible shifts in diversification of nonflowering seed plants, but find significantly decreased extinction in spore-bearing plants and increased origination rates in angiosperms, contributing to their current ecological and evolutionary dominance. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

A Novel Source of DOC and DON to Watershed Soils

Science.gov (United States)

Aitkenhead-Peterson, J. A.

2017-12-01

A source of dissolved organic carbon (DOC) and nitrogen (DON) to soils and groundwater is that emanating from decomposing mammals. Although there is an increase in human donor facilities (body farms) in the USA and in mass mortality events (MME) worldwide, this injection of DOC and DON into watershed soils has received little attention. Studies at two human donor facilities in Texas, USA have revealed that the purge fluid associated with decomposition is extremely high in DOC and DON and migrates down the soil profile. Two studies were carried out 1) The southeast Texas Applied Forensic Science (STAFS) facility on an Alfisol with a saturated hydraulic conductivity of 331 mm hr-1 and 83% sand and 2) the Forensic Anthropology Research Facility (FARF) on Mollisols with a saturated hydraulic conductivity of 3.6-9.7 mm hr-1 and 28-33% sand. The numbers of days since donors were laid in the environment ranged from 219-680 d at STAFS and 306-960 d at FACTS. Purge can occur between 5 and 30 d dependent on the time of year the body is placed and the resultant phenomenon is termed cadaver decomposition island (CDI). Soil cores were taken at 5 cm increments to a depth of 30 cm in the sandy soil and 15 cm in the clayey/rocky soil. In the sandy soils, DOC concentrations were significantly higher in all the CDI soils when compared to control soils at depths of 15, 20, 25 and 30 cm and ranged from 121.7 µg g-1 (30 cm) to 167.6 µg g-1 (15 cm) in control soils and 461.9 µg g-1 (30 cm) to 660.4 µg g-1 (15 cm) in CDI soils, representing a three- to four-fold increase in DOC relative to control soils. DON in all CDI soils was not significantly higher than control soils until 30 cm depth and ranged from 9.9-32.3 µg g-1 in CDI soils and 121.7 µg g-1 in control soil, representing a two- to seven-fold increase in DON relative to control soils. DOC concentrations in control soils at the FARF site at 15 cm ranged 215-365 µg g-1 while in the CDI soils DOC was higher (range: 270

Investigations of freezing and cold storage for the analysis of peatland dissolved organic carbon (DOC) and absorbance properties.

Science.gov (United States)

Peacock, Mike; Freeman, Chris; Gauci, Vincent; Lebron, Inma; Evans, Chris D

2015-07-01

Although measured rates of biological degradation of DOC are typically low under dark conditions, it is assumed that water samples must be analysed soon after collection to provide an accurate measure of DOC concentration and UV-visible absorbance. To examine the impact of storage on DOC quality and quantity, we took water samples from an ombrotrophic peatland, and stored them in the dark at 4 °C for 138-1082 days. A median of 29% of DOC was lost during storage, but losses of absorbance at 254 nm were less. DOC loss followed a first-order exponential decay function, and was dependent on storage time. DOC half-life was calculated as 1253 days. Specific absorbance at 254 nm suggested that samples containing more aromatic DOC were more resistant to degradation, although time functioned as the primary control. Samples from two fens showed that loss of absorbance was greater at 400 nm rather than 254 nm, after 192 days storage, suggesting that non-aromatic DOC is preferentially degraded. These results suggest that samples can be stored for several months before losses of DOC become detectable, and that it is possible to back-calculate initial DOC concentrations in long-term stored samples based on known decay rates. Freeze/thaw experiments using samples from a range of peatlands suggested that DOC concentration was mostly unaffected by the process, but DOC increased 37% in one sample. Freezing had unpredictable and sometimes strong effects on absorbance, SUVA and E ratios, therefore freezing is not recommended as a method of preservation for these analyses.

The moss Funaria hygrometrica has cuticular wax similar to vascular plants, with distinct composition on leafy gametophyte, calyptra and sporophyte capsule surfaces.

Science.gov (United States)

Busta, Lucas; Budke, Jessica M; Jetter, Reinhard

2016-09-01

Aerial surfaces of land plants are covered with a waxy cuticle to protect against water loss. The amount and composition of cuticular waxes on moss surfaces had rarely been investigated. Accordingly, the degree of similarity between moss and vascular plant waxes, and between maternal and offspring moss structure waxes is unknown. To resolve these issues, this study aimed at providing a comprehensive analysis of the waxes on the leafy gametophyte, gametophyte calyptra and sporophyte capsule of the moss Funaria hygrometrica Waxes were extracted from the surfaces of leafy gametophytes, gametophyte calyptrae and sporophyte capsules, separated by gas chromatography, identified qualitatively with mass spectrometry, and quantified with flame ionization detection. Diagnostic mass spectral peaks were used to determine the isomer composition of wax esters. The surfaces of the leafy gametophyte, calyptra and sporophyte capsule of F. hygrometrica were covered with 0·94, 2·0 and 0·44 μg cm(-2) wax, respectively. While each wax mixture was composed of mainly fatty acid alkyl esters, the waxes from maternal and offspring structures had unique compositional markers. β-Hydroxy fatty acid alkyl esters were limited to the leafy gametophyte and calyptra, while alkanes, aldehydes and diol esters were restricted to the sporophyte capsule. Ubiquitous fatty acids, alcohols, fatty acid alkyl esters, aldehydes and alkanes were all found on at least one surface. This is the first study to determine wax coverage (μg cm(-2)) on a moss surface, enabling direct comparisons with vascular plants, which were shown to have an equal amount or more wax than F. hygrometrica Wax ester biosynthesis is of particular importance in this species, and the ester-forming enzyme(s) in different parts of the moss may have different substrate preferences. Furthermore, the alkane-forming wax biosynthesis pathway, found widely in vascular plants, is active in the sporophyte capsule, but not in the leafy

G-DOC: A Systems Medicine Platform for Personalized Oncology

Directory of Open Access Journals (Sweden)

Subha Madhavan

2011-09-01

Full Text Available Currently, cancer therapy remains limited by a “one-size-fits-all” approach, whereby treatment decisions are based mainly on the clinical stage of disease, yet fail to reference the individual's underlying biology and its role driving malignancy. Identifying better personalized therapies for cancer treatment is hindered by the lack of high-quality “omics” data of sufficient size to produce meaningful results and the ability to integrate biomedical data from disparate technologies. Resolving these issues will help translation of therapies from research to clinic by helping clinicians develop patient-specific treatments based on the unique signatures of patient's tumor. Here we describe the Georgetown Database of Cancer (G-DOC, a Web platform that enables basic and clinical research by integrating patient characteristics and clinical outcome data with a variety of high-throughput research data in a unified environment. While several rich data repositories for high-dimensional research data exist in the public domain, most focus on a single-data type and do not support integration across multiple technologies. Currently, G-DOC contains data from more than 2500 breast cancer patients and 800 gastrointestinal cancer patients, G-DOC includes a broad collection of bioinformatics and systems biology tools for analysis and visualization of four major “omics” types: DNA, mRNA, microRNA, and metabolites. We believe that G-DOC will help facilitate systems medicine by providing identification of trends and patterns in integrated data sets and hence facilitate the use of better targeted therapies for cancer. A set of representative usage scenarios is provided to highlight the technical capabilities of this resource.

The intrinsically disordered domain of the antitoxin Phd chaperones the toxin Doc against irreversible inactivation and misfolding.

Science.gov (United States)

De Gieter, Steven; Konijnenberg, Albert; Talavera, Ariel; Butterer, Annika; Haesaerts, Sarah; De Greve, Henri; Sobott, Frank; Loris, Remy; Garcia-Pino, Abel

2014-12-05

The toxin Doc from the phd/doc toxin-antitoxin module targets the cellular translation machinery and is inhibited by its antitoxin partner Phd. Here we show that Phd also functions as a chaperone, keeping Doc in an active, correctly folded conformation. In the absence of Phd, Doc exists in a relatively expanded state that is prone to dimerization through domain swapping with its active site loop acting as hinge region. The domain-swapped dimer is not capable of arresting protein synthesis in vitro, whereas the Doc monomer is. Upon binding to Phd, Doc becomes more compact and is secured in its monomeric state with a neutralized active site. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

75 FR 16748 - Final Voluntary Product Standard; DOC PS 20-10 “American Softwood Lumber Standard”

Science.gov (United States)

2010-04-02

...-0146-02] Final Voluntary Product Standard; DOC PS 20-10 ``American Softwood Lumber Standard'' AGENCY... of Standards and Technology (NIST) announces voluntary product standard DOC PS 20-10 ``American Softwood Lumber Standard'' which will supersede DOC PS 20-05. The Standard establishes standard sizes and...

DOC concentrations across a depth-dependent light gradient on a Caribbean coral reef

NARCIS (Netherlands)

Mueller, Benjamin; Meesters, Erik H.; Duyl, Van Fleur C.

2017-01-01

Photosynthates released by benthic primary producers (BPP), such as reef algae and scleractinian corals, fuel the dissolved organic carbon (DOC) production on tropical coral reefs. DOC concentrations near BPP have repeatedly been observed to be elevated compared to those in the surrounding water

A systematic examination of the relationship between CDOM and DOC for various inland waters across China

OpenAIRE

Song, Kaishan; Zhao, Ying; Wen, Zhidan; Ma, Jianhang; Shao, Tiantian; Fang, Chong; Shang, Yingxin

2016-01-01

Chromophoric dissolved organic matter (CDOM) plays a vital role in aquatic ecosystems. Strong relationship has been proven between CDOM and dissolved organic carbon (DOC), which set the basis for remote estimation of DOC with remote sensing data. An algorithm has been developed to retrieve DOC via CDOM absorption at 275 and 295 nm with coastal waters. However, the relationship between DOC and aCDOM(275) and aCDOM(295) for different types of inland waters are still not clear. Further, i...

Effect of light and nutrient availability on the release of dissolved organic carbon (DOC) by Caribbean turf algae.

Science.gov (United States)

Mueller, Benjamin; den Haan, Joost; Visser, Petra M; Vermeij, Mark J A; van Duyl, Fleur C

2016-03-22

Turf algae increasingly dominate benthic communities on coral reefs. Given their abundance and high dissolved organic carbon (DOC) release rates, turf algae are considered important contributors to the DOC pool on modern reefs. The release of photosynthetically fixed carbon as DOC generally, but not always, increases with increased light availability. Nutrient availability was proposed as an additional factor to explain these conflicting observations. To address this proposed but untested hypothesis, we documented the interactive contributions of light and nutrient availability on the release of DOC by turf algae. DOC release rates and oxygen production were quantified in incubation experiments at two light levels (full and reduced light) and two nutrient treatments (natural seawater and enriched seawater). In natural seawater, DOC release at full light was four times higher than at reduced light. When nutrients were added, DOC release rates at both light levels were similar to the natural seawater treatment at full light. Our results therefore show that low light in combination with low nutrient availability reduces the release of DOC by turf algae and that light and nutrient availability interactively determine DOC release rates by this important component of Caribbean reef communities.

78 FR 35093 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel EYE DOC; Invitation for...

Science.gov (United States)

2013-06-11

... Administrative Waiver of the Coastwise Trade Laws: Vessel EYE DOC; Invitation for Public Comments AGENCY... DOC is: INTENDED COMMERCIAL USE OF VESSEL: ``Charter fishing on Lake Erie'' GEOGRAPHIC REGION: ``Ohio..., Maritime Administration. [FR Doc. 2013-13836 Filed 6-10-13; 8:45 am] BILLING CODE 4910-81-P ...

The effect of drought on dissolved organic carbon (DOC) release from peatland soil and vegetation sources

Science.gov (United States)

Ritson, Jonathan P.; Brazier, Richard E.; Graham, Nigel J. D.; Freeman, Chris; Templeton, Michael R.; Clark, Joanna M.

2017-06-01

Drought conditions are expected to increase in frequency and severity as the climate changes, representing a threat to carbon sequestered in peat soils. Downstream water treatment works are also at risk of regulatory compliance failures and higher treatment costs due to the increase in riverine dissolved organic carbon (DOC) often observed after droughts. More frequent droughts may also shift dominant vegetation in peatlands from Sphagnum moss to more drought-tolerant species. This paper examines the impact of drought on the production and treatability of DOC from four vegetation litters (Calluna vulgaris, Juncus effusus, Molinia caerulea and Sphagnum spp.) and a peat soil. We found that mild droughts caused a 39.6 % increase in DOC production from peat and that peat DOC that had been exposed to oxygen was harder to remove by conventional water treatment processes (coagulation/flocculation). Drought had no effect on the amount of DOC production from vegetation litters; however large variation was observed between typical peatland species (Sphagnum and Calluna) and drought-tolerant grassland species (Juncus and Molinia), with the latter producing more DOC per unit weight. This would therefore suggest the increase in riverine DOC often observed post-drought is due entirely to soil microbial processes and DOC solubility rather than litter layer effects. Long-term shifts in species diversity may, therefore, be the most important impact of drought on litter layer DOC flux, whereas pulses related to drought may be observed in peat soils and are likely to become more common in the future. These results provide evidence in support of catchment management which increases the resilience of peat soils to drought, such as ditch blocking to raise water tables.

A clade in the QUASIMODO2 family evolved with vascular plants and supports a role for cell wall composition in adaptation to environmental changes.

Science.gov (United States)

Fuentes, Sara; Pires, Nuno; Østergaard, Lars

2010-08-01

The evolution of plant vascular tissue is tightly linked to the evolution of specialised cell walls. Mutations in the QUASIMODO2 (QUA2) gene from Arabidopsis thaliana were previously shown to result in cell adhesion defects due to reduced levels of the cell wall component homogalacturonic acid. In this study, we provide additional information about the role of QUA2 and its closest paralogues, QUASIMODO2 LIKE1 (QUL1) and QUL2. Within the extensive QUA2 family, our phylogenetic analysis shows that these three genes form a clade that evolved with vascular plants. Consistent with a possible role of this clade in vasculature development, QUA2 is highly expressed in the vascular tissue of embryos and inflorescence stems and overexpression of QUA2 resulted in temperature-sensitive xylem collapse. Moreover, in-depth characterisation of qua2 qul1 qul2 triple mutant and 35S::QUA2 overexpression plants revealed contrasting temperature-dependent stem development with dramatic effects on stem width. Taken together, our results suggest that the QUA2-specific clade contributed to the evolution of vasculature and illustrate the important role that modification of cell wall composition plays in the adaptation to changing environmental conditions, including changes in temperature.

Variable flushing mechanisms and landscape structure control stream DOC export during snowmelt in a set of nested catchments

Science.gov (United States)

Vincent J. Pacific; Kelsey G. Jencso; Brian L. McGlynn

2010-01-01

Stream DOC dynamics during snowmelt have been the focus of much research, and numerous DOC mobilization and delivery mechanisms from riparian and upland areas have been proposed. However, landscape structure controls on DOC export from riparian and upland landscape elements remains poorly understood. We investigated stream and groundwater DOC dynamics across three...

Algorithm Development and Validation for Satellite-Derived Distributions of DOC and CDOM in the US Middle Atlantic Bight

Science.gov (United States)

Mannino, Antonio; Russ, Mary E.; Hooker, Stanford B.

2007-01-01

In coastal ocean waters, distributions of dissolved organic carbon (DOC) and chromophoric dissolved organic matter (CDOM) vary seasonally and interannually due to multiple source inputs and removal processes. We conducted several oceanographic cruises within the continental margin of the U.S. Middle Atlantic Bight (MAB) to collect field measurements in order to develop algorithms to retrieve CDOM and DOC from NASA's MODIS-Aqua and SeaWiFS satellite sensors. In order to develop empirical algorithms for CDOM and DOC, we correlated the CDOM absorption coefficient (a(sub cdom)) with in situ radiometry (remote sensing reflectance, Rrs, band ratios) and then correlated DOC to Rrs band ratios through the CDOM to DOC relationships. Our validation analyses demonstrate successful retrieval of DOC and CDOM from coastal ocean waters using the MODIS-Aqua and SeaWiFS satellite sensors with mean absolute percent differences from field measurements of cdom)(355)1,6 % for a(sub cdom)(443), and 12% for the CDOM spectral slope. To our knowledge, the algorithms presented here represent the first validated algorithms for satellite retrieval of a(sub cdom) DOC, and CDOM spectral slope in the coastal ocean. The satellite-derived DOC and a(sub cdom) products demonstrate the seasonal net ecosystem production of DOC and photooxidation of CDOM from spring to fall. With accurate satellite retrievals of CDOM and DOC, we will be able to apply satellite observations to investigate interannual and decadal-scale variability in surface CDOM and DOC within continental margins and monitor impacts of climate change and anthropogenic activities on coastal ecosystems.

Cold storage as a method for the long-term preservation of tropical dissolved organic carbon (DOC

Directory of Open Access Journals (Sweden)

S. Cook

2016-11-01

Full Text Available Fluvial fluxes of dissolved organic carbon (DOC may represent an important loss for terrestrial carbon stores in the tropics. However, there is currently limited guidance on the preservation of tropical water samples for DOC analysis. Commonly employed preservation techniques such as freezing or acidification can limit degradation but may also alter sample properties, complicating DOC analysis. We examined the effects of cold storage at 4 °C on DOC concentration and quality in water samples collected from a tropical peat catchment. Samples were stored in the dark at 4 °C for periods of 6–12 weeks. Freeze/thaw experiments were also made. Mean DOC concentrations in samples stored for six weeks at 4 °C were 6.1 % greater than in samples stored at ambient room temperature (33 °C over the same period. Changes in DOC concentrations, in two sample sets, during cold storage were 2.25 ± 2.9 mg L-1 (8 % to 2.69 ± 1.4 mg L-1 (11 % over a 12-week period. Freeze/thaw resulted in alterations in the optical properties of samples, and this in turn altered the calculated DOC concentrations by an average of 10.9 %. We conclude that cold storage at 4 °C is an acceptable preservation method for tropical DOC water samples, for moderate time periods, and is preferable to freezing or storage at ambient temperatures.

Decreased DOC concentrations in soil water in forested areas in southern Sweden during 1987-2008.

Science.gov (United States)

Löfgren, Stefan; Zetterberg, Therese

2011-04-15

During the last two decades, there is a common trend of increasing concentrations of dissolved organic carbon (DOC) in streams and lakes in Europe, Canada and the US. Different processes have been proposed to explain this trend and recently a unifying hypothesis was presented, concluding that declining sulphur deposition and recovery from acidification, is the single most important factor for the long-term DOC concentration trends in surface waters. If this recovery hypothesis is correct, the soil water DOC concentrations should increase as well. However, long-term soil water data from Sweden and Norway indicate that there are either decreasing or indifferent DOC concentrations, while positive DOC trends have been found in the Czech Republic. Based on the soil water data from two Swedish integrated monitoring sites and geochemical modelling, it has been shown that depending on changes in pH, ionic strength and soil Al pools, the DOC solubility might be positive, negative or indifferent. In this study, we test the acidification recovery hypothesis on long-term soil water data (25 and 50cm soil depth) from 68 forest covered sites in southern Sweden, showing clear signs of recovery from acidification. The main aim was to identify potential drivers for the DOC solubility in soil solution by comparing trends in DOC concentrations with observed changes in pH, ionic strength and concentrations of Al(n+). As in earlier Swedish and Norwegian studies, the DOC concentrations in soil water decreased or showed no trend. The generally small increases in pH (median <0.3 pH units) during the investigation period seem to be counterbalanced by the reduced ionic strength and diminished Al concentrations, increasing the organic matter coagulation. Hence, opposite to the conclusion for surface waters, the solubility of organic matter seems to decrease in uphill soils, as a result of the acidification recovery. Copyright © 2011 Elsevier B.V. All rights reserved.

Post-translational control of nitrate reductase activity responding to light and photosynthesis evolved already in the early vascular plants.

Science.gov (United States)

Nemie-Feyissa, Dugassa; Królicka, Adriana; Førland, Nina; Hansen, Margarita; Heidari, Behzad; Lillo, Cathrine

2013-05-01

Regulation of nitrate reductase (NR) by reversible phosphorylation at a conserved motif is well established in higher plants, and enables regulation of NR in response to rapid fluctuations in light intensity. This regulation is not conserved in algae NR, and we wished to test the evolutionary origin of the regulatory mechanism by physiological examination of ancient land plants. Especially a member of the lycophytes is of interest since their NR is candidate for regulation by reversible phosphorylation based on sequence analysis. We compared Selaginella kraussiana, a member of the lycophytes and earliest vascular plants, with the angiosperm Arabidopsis thaliana, and also tested the moss Physcomitrella patens. Interestingly, optimization of assay conditions revealed that S. kraussiana NR used NADH as an electron donor like A. thaliana, whereas P. patens NR activity depended on NADPH. Examination of light/darkness effects showed that S. kraussiana NR was rapidly regulated similar to A. thaliana NR when a differential (Mg(2+) contra EDTA) assay was used to reveal activity state of NR. This implies that already existing NR enzyme was post-translationally activated by light in both species. Light had a positive effect also on de novo synthesis of NR in S. kraussiana, which could be shown after the plants had been exposed to a prolonged dark period (7 days). Daily variations in NR activity were mainly caused by post-translational modifications. As for angiosperms, the post-translational light activation of NR in S. kraussiana was inhibited by 3-(3,4-dichlorophenyl)-1*1-dimethylurea (DCMU), an inhibitor of photosynthesis and stomata opening. Evolutionary, a post-translational control mechanism for NR have occurred before or in parallel with development of vascular tissue in land plants, and appears to be part of a complex mechanisms for coordination of CO2 and nitrogen metabolism in these plants. Copyright © 2013 Elsevier GmbH. All rights reserved.

Dissolved organic carbon (DOC) concentrations in UK soils and the influence of soil, vegetation type and seasonality.

Science.gov (United States)

van den Berg, Leon J L; Shotbolt, Laura; Ashmore, Mike R

2012-06-15

Given the lack of studies which measured dissolved organic carbon (DOC) over long periods, especially in non-forest habitat, the aim of this study was to expand the existing datasets with data of mainly non-forest sites that were representative of the major soil and habitat types in the UK. A further aim was to predict DOC concentrations from a number of biotic and abiotic explanatory variables such as rainfall, temperature, vegetation type and soil type in a multivariate way. Pore water was sampled using Rhizon or Prenart samplers at two to three week intervals for 1 year. DOC, pH, organic carbon, carbon/nitrogen (C:N) ratios of soils and slope were measured and data on vegetation, soil type, temperature and precipitation were obtained. The majority of the variation in DOC concentrations between the UK sites could be explained by simple empirical models that included annual precipitation, and soil C:N ratio with precipitation being negatively related to DOC concentrations and C:N ratio being positively related to DOC concentrations. Our study adds significantly to the data reporting DOC concentrations in soils, especially in grasslands, heathlands and moorlands. Broad climatic and site factors have been identified as key factors influencing DOC concentrations. Copyright © 2012 Elsevier B.V. All rights reserved.

Mosses Are Better than Leaves of Vascular Plants in Monitoring Atmospheric Heavy Metal Pollution in Urban Areas.

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Jiang, Yanbin; Fan, Miao; Hu, Ronggui; Zhao, Jinsong; Wu, Yupeng

2018-05-29

Mosses and leaves of vascular plants have been used as bioindicators of environmental contamination by heavy metals originating from various sources. This study aims to compare the metal accumulation capabilities of mosses and vascular species in urban areas and quantify the suitability of different taxa for monitoring airborne heavy metals. One pleurocarpous feather moss species, Haplocladium angustifolium , and two evergreen tree species, Cinnamomum bodinieri Osmanthus fragrans , and substrate soil were sampled in the urban area of different land use types in Wuhan City in China. The concentrations of Ag, As, Cd, Co, Cr, Cu, Mn, Mo, Ni, V, Pb, and Zn in these samples were analyzed by inductively coupled plasma mass spectrometry. The differences of heavy metals concentration in the three species showed that the moss species was considerably more capable of accumulating heavy metals than tree leaves (3 times to 51 times). The accumulated concentration of heavy metals in the moss species depended on the metal species and land use type. The enrichment factors of metals for plants and the correlations of metals in plants with corresponding metals in soil reflected that the accumulated metals in plants stemmed mostly from atmospheric deposition, rather than the substrate soil. Anthropogenic factors, such as traffic emissions from automobile transportation and manufacturing industries, were primarily responsible for the variations in metal pollutants in the atmosphere and subsequently influenced the metal accumulation in the mosses. This study elucidated that the moss species H. angustifolium is relatively more suitable than tree leaves of C. bodinieri and O. fragrans in monitoring heavy metal pollution in urban areas, and currently Wuhan is at a lower contamination level of atmospheric heavy metals than some other cities in China.

Soft X-ray induced chemical modification of polysaccharides in vascular plant cell walls

International Nuclear Information System (INIS)

Cody, George D.; Brandes, Jay; Jacobsen, Chris; Wirick, Susan

2009-01-01

Scanning transmission X-ray microscopy and micro carbon X-ray Absorption Near Edge Spectroscopy (C-XANES) can provide quantitative information regarding the distribution of the biopolymers cellulose, hemicellulose, and lignin in vascular plant cell walls. In the case of angiosperms, flowering plants, C-XANES may also be able to distinguish variations in lignin monomer distributions throughout the cell wall. Polysaccharides are susceptible to soft X-ray irradiation induced chemical transformations that may complicate spectral analysis. The stability of a model polysaccharide, cellulose acetate, to variable doses of soft X-rays under conditions optimized for high quality C-XANES spectroscopy was investigated. The primary chemical effect of soft X-ray irradiation on cellulose acetate involves mass loss coincident with de-acetylation. A lesser amount of vinyl ketone formation also occurs. Reduction in irradiation dose via defocusing does enable high quality pristine spectra to be obtained. Radiation induced chemical modification studies of oak cell wall reveals that cellulose and hemicellulose are less labile to chemical modification than cellulose acetate. Strategies for obtaining pristine C-XANES spectra of polysaccharides are presented.

Leaching of DOC, DN, and inorganic constituents from scrap tires.

Science.gov (United States)

Selbes, Meric; Yilmaz, Ozge; Khan, Abdul A; Karanfil, Tanju

2015-11-01

One concern for recycle and reuse of scrap tires is the leaching of tire constituents (organic and inorganic) with time, and their subsequent potential harmful impacts in environment. The main objective of this study was to examine the leaching of dissolved organic carbon (DOC), dissolved nitrogen (DN), and selected inorganic constituents from scrap tires. Different sizes of tire chips and crumb rubber were exposed to leaching solutions with pH's ranging from 3.0 to 10.0 for 28days. The leaching of DOC and DN were found to be higher for smaller size tire chips; however, the leaching of inorganic constituents was independent of the size. In general, basic pH conditions increased the leaching of DOC and DN, whereas acidic pH conditions led to elevated concentrations of metals. Leaching was minimal around the neutral pH values for all the monitored parameters. Analysis of the leaching rates showed that components associated with the rubbery portion of the tires (DOC, DN, zinc, calcium, magnesium, etc.) exhibited an initial rapid followed by a slow release. On the other hand, a constant rate of leaching was observed for iron and manganese, which are attributed to the metal wires present inside the tires. Although the total amounts that leached varied, the observed leaching rates were similar for all tire chip sizes and leaching solutions. Operation under neutral pH conditions, use of larger size tire chips, prewashing of tires, and removal of metal wires prior to application will reduce the impact of tire recycle and reuse. Copyright © 2015 Elsevier Ltd. All rights reserved.

Linking soil DOC production rates and transport processes from landscapes to sub-basin scales

Science.gov (United States)

Tian, Y. Q.; Yu, Q.; Li, J.; Ye, C.

2014-12-01

Recent research rejects the traditional perspective that dissolved organic carbon (DOC) component in global carbon cycle are simply trivial, and in fact evidence demonstrates that lakes likely mediate carbon dynamics on a global scale. Riverine and estuarine carbon fluxes play a critical role in transporting and recycling carbon and nutrients, not only within watersheds but in their receiving waters. However, the underlying mechanisms that drive carbon fluxes, from land to rivers, lake and oceans, remain poorly understood. This presentation will report a research result of the scale-dependent DOC production rate in coastal watersheds and DOC transport processes in estuarine regions. We conducted a series of controlled experiments and field measurements for examining biogeochemical, biological, and geospatial variables that regulate downstream processing on global-relevant carbon fluxes. Results showed that increased temperatures and raised soil moistures accelerate decomposition rates of organic matter with significant variations between vegetation types. The measurements at meso-scale ecosystem demonstrated a good correlation to bulk concentration of DOC monitored in receiving waters at the outlets of sub-basins (R2 > 0.65). These field and experimental measurements improved the model of daily carbon exports through below-ground processes as a function of the organic matter content of surface soils, forest litter supply, and temperature. The study demonstrated a potential improvement in modeling the co-variance of CDOM and DOC with the unique terrestrial sources. This improvement indicated a significant promise for monitoring riverine and estuarine carbon flux from satellite images. The technical innovations include deployments of 1) mini-ecosystem (mesocosms) with soil as replicate controlled experiments for DOC production and leaching rates, and 2) aquatic mesocosms for co-variances of DOC and CDOM endmembers, and an instrumented incubation experiment for

Spatial and Seasonal Variation of dissolved organic carbon (DOC) concentrations in Irish streams: importance of soil and topography characteristics.

Science.gov (United States)

Liu, Wen; Xu, Xianli; McGoff, Nicola M; Eaton, James M; Leahy, Paul; Foley, Nelius; Kiely, Gerard

2014-05-01

Dissolved organic carbon (DOC) concentrations have increased in many sites in Europe and North America in recent decades. High DOC concentrations can damage the structure and functions of aquatic ecosystems by influencing water chemistry. This study investigated the spatial and seasonal variation of DOC concentrations in Irish streams across 55 sites at seven time occasions over 1 year (2006/2007). The DOC concentrations ranged from 0.9 to 25.9 mg/L with a mean value of 6.8 and a median value of 5.7 mg/L and varied significantly over the course of the year. The DOC concentrations from late winter (February: 5.2 ± 3.0 mg/L across 55 sites) and early spring (April: 4.5 ± 3.5 mg/L) had significantly lower DOC concentrations than autumn (October: mean 8.3 ± 5.6 mg/L) and early winter (December: 8.3 ± 5.1 mg/L). The DOC production sources (e.g., litterfall) or the accumulation of DOC over dry periods might be the driving factor of seasonal change in Irish stream DOC concentrations. Analysis of data using stepwise multiple linear regression techniques identified the topographic index (TI, an indication of saturation-excess runoff potential) and soil conditions (organic carbon content and soil drainage characteristics) as key factors in controlling DOC spatial variation in different seasons. The TI and soil carbon content (e.g., soil organic carbon; peat occurrence) are positively related to DOC concentrations, while well-drained soils are negatively related to DOC concentrations. The knowledge of spatial and seasonal variation of DOC concentrations in streams and their drivers are essential for optimum riverine water resources management.

A transcriptional coregulator, SPIN·DOC, attenuates the coactivator activity of Spindlin1.

Science.gov (United States)

Bae, Narkhyun; Gao, Min; Li, Xu; Premkumar, Tolkappiyan; Sbardella, Gianluca; Chen, Junjie; Bedford, Mark T

2017-12-22

Spindlin1 (SPIN1) is a transcriptional coactivator with critical functions in embryonic development and emerging roles in cancer. SPIN1 harbors three Tudor domains, two of which engage the tail of histone H3 by reading the H3-Lys-4 trimethylation and H3-Arg-8 asymmetric dimethylation marks. To gain mechanistic insight into how SPIN1 functions as a transcriptional coactivator, here we purified its interacting proteins. We identified an uncharacterized protein (C11orf84), which we renamed SPIN1 docking protein (SPIN·DOC), that directly binds SPIN1 and strongly disrupts its histone methylation reading ability, causing it to disassociate from chromatin. The Spindlin family of coactivators has five related members (SPIN1, 2A, 2B, 3, and 4), and we found that all of them bind SPIN·DOC. It has been reported previously that SPIN1 regulates gene expression in the Wnt signaling pathway by directly interacting with transcription factor 4 (TCF4). We observed here that SPIN·DOC associates with TCF4 in a SPIN1-dependent manner and dampens SPIN1 coactivator activity in TOPflash reporter assays. Furthermore, knockdown and overexpression experiments indicated that SPIN·DOC represses the expression of a number of SPIN1-regulated genes, including those encoding ribosomal RNA and the cytokine IL1B. In conclusion, we have identified SPIN·DOC as a transcriptional repressor that binds SPIN1 and masks its ability to engage the H3-Lys-4 trimethylation activation mark. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Vascular plant biodiversity of the lower Coppermine River valley and vicinity (Nunavut, Canada: an annotated checklist of an Arctic flora

Directory of Open Access Journals (Sweden)

Jeffery M. Saarela

2017-01-01

Full Text Available The Coppermine River in western Nunavut is one of Canada’s great Arctic rivers, yet its vascular plant flora is poorly known. Here, we report the results of a floristic inventory of the lower Coppermine River valley and vicinity, including Kugluk (Bloody Falls Territorial Park and the hamlet of Kugluktuk. The study area is approximately 1,200 km2, extending from the forest-tundra south of the treeline to the Arctic coast. Vascular plant floristic data are based on a review of all previous collections from the area and more than 1,200 new collections made in 2014. Results are presented in an annotated checklist, including citation of all specimens examined, comments on taxonomy and distribution, and photographs for a subset of taxa. The vascular plant flora comprises 300 species (311 taxa, a 36.6% increase from the 190 species documented by previous collections made in the area over the last century, and is considerably more diverse than other local floras on mainland Nunavut. We document 207 taxa for Kugluk (Bloody Falls Territorial Park, an important protected area for plants on mainland Nunavut. A total of 190 taxa are newly recorded for the study area. Of these, 14 taxa (13 species and one additional variety are newly recorded for Nunavut (Allium schoenoprasum, Carex capitata, Draba lonchocarpa, Eremogone capillaris subsp. capillaris, Sabulina elegans, Eleocharis quinqueflora, Epilobium cf. anagallidifolium, Botrychium neolunaria, Botrychium tunux, Festuca altaica, Polygonum aviculare, Salix ovalifolia var. arctolitoralis, Salix ovalifolia var. ovalifolia and Stuckenia pectinata, seven species are newly recorded for mainland Nunavut (Carex gynocrates, Carex livida, Cryptogramma stelleri, Draba simmonsii, Festuca viviparoidea subsp. viviparoidea, Juncus alpinoarticulatus subsp. americanus and Salix pseudomyrsinites and 56 range extensions are reported. The psbA-trnH and rbcL DNA sequence data were used to help identify the three Botrychium

Degree of contribution (DoC) feature selection algorithm for structural brain MRI volumetric features in depression detection.

Science.gov (United States)

Kipli, Kuryati; Kouzani, Abbas Z

2015-07-01

Accurate detection of depression at an individual level using structural magnetic resonance imaging (sMRI) remains a challenge. Brain volumetric changes at a structural level appear to have importance in depression biomarkers studies. An automated algorithm is developed to select brain sMRI volumetric features for the detection of depression. A feature selection (FS) algorithm called degree of contribution (DoC) is developed for selection of sMRI volumetric features. This algorithm uses an ensemble approach to determine the degree of contribution in detection of major depressive disorder. The DoC is the score of feature importance used for feature ranking. The algorithm involves four stages: feature ranking, subset generation, subset evaluation, and DoC analysis. The performance of DoC is evaluated on the Duke University Multi-site Imaging Research in the Analysis of Depression sMRI dataset. The dataset consists of 115 brain sMRI scans of 88 healthy controls and 27 depressed subjects. Forty-four sMRI volumetric features are used in the evaluation. The DoC score of forty-four features was determined as the accuracy threshold (Acc_Thresh) was varied. The DoC performance was compared with that of four existing FS algorithms. At all defined Acc_Threshs, DoC outperformed the four examined FS algorithms for the average classification score and the maximum classification score. DoC has a good ability to generate reduced-size subsets of important features that could yield high classification accuracy. Based on the DoC score, the most discriminant volumetric features are those from the left-brain region.

A systematic examination of the relationships between CDOM and DOC in inland waters in China

Science.gov (United States)

Song, Kaishan; Zhao, Ying; Wen, Zhidan; Fang, Chong; Shang, Yingxin

2017-10-01

Chromophoric dissolved organic matter (CDOM) plays a vital role in the biogeochemical cycle in aquatic ecosystems. The relationship between CDOM and dissolved organic carbon (DOC) has been investigated, and this significant relationship lays the foundation for the estimation of DOC using remotely sensed imagery data. The current study examined samples from freshwater lakes, saline lakes, rivers and streams, urban water bodies, and ice-covered lakes in China for tracking the variation of the relationships between DOC and CDOM. The regression model slopes for DOC vs. aCDOM (275) ranged from extremely low 0.33 (highly saline lakes) to 1.03 (urban waters) and 3.01 (river waters). The low values were observed in saline lake waters and waters from semi-arid or arid regions, where strong photobleaching is expected due to less cloud cover, longer water residence time, and daylight hours. In contrast, high values were found in waters developed in wetlands or forest in Northeast China, where more organic matter was transported from catchment to waters. The study also demonstrated that closer relationships between CDOM and DOC were revealed when aCDOM (275) were sorted by the ratio of aCDOM(250)/aCDOM (365), which is a measure for the CDOM absorption with respect to its composition, and the determination of coefficient of the regression models ranged from 0.79 to 0.98 for different groups of waters. Our results indicate the relationships between CDOM and DOC are variable for different inland waters; thus, models for DOC estimation through linking with CDOM absorption need to be tailored according to water types.

Can oxygen stable isotopes be used to track precipitation moisture source in vascular plant-dominated peatlands?

Science.gov (United States)

Amesbury, Matthew J.; Charman, Dan J.; Newnham, Rewi M.; Loader, Neil J.; Goodrich, Jordan; Royles, Jessica; Campbell, David I.; Keller, Elizabeth D.; Baisden, W. Troy; Roland, Thomas P.; Gallego-Sala, Angela V.

2015-11-01

Variations in the isotopic composition of precipitation are determined by fractionation processes which occur during temperature- and humidity-dependent phase changes associated with evaporation and condensation. Oxygen stable isotope ratios have therefore been frequently used as a source of palaeoclimate data from a variety of proxy archives, which integrate this signal over time. Applications from ombrotrophic peatlands, where the source water used in cellulose synthesis is derived solely from precipitation, have been mostly limited to Northern Hemisphere Sphagnum-dominated bogs, with few in the Southern Hemisphere or in peatlands dominated by vascular plants. New Zealand (NZ) provides an ideal location to undertake empirical research into oxygen isotope fractionation in vascular peatlands because single taxon analysis can be easily carried out, in particular using the preserved root matrix of the restionaceous wire rush (Empodisma spp.) that forms deep Holocene peat deposits throughout the country. Furthermore, large gradients are observed in the mean isotopic composition of precipitation across NZ, caused primarily by the relative influence of different climate modes. Here, we test whether δ18O of Empodisma α-cellulose from ombrotrophic restiad peatlands in NZ can provide a methodology for developing palaeoclimate records of past precipitation δ18O. Surface plant, water and precipitation samples were taken over spatial (six sites spanning >10° latitude) and temporal (monthly measurements over one year) gradients. A link between the isotopic composition of root-associated water, the most likely source water for plant growth, and precipitation in both datasets was found. Back-trajectory modelling of precipitation moisture source for rain days prior to sampling showed clear seasonality in the temporal data that was reflected in root-associated water. The link between source water and plant cellulose was less clear, although mechanistic modelling predicted mean

5alphaDH-DOC (5alpha-dihydro-deoxycorticosterone) activates androgen receptor in castration-resistant prostate cancer.

Science.gov (United States)

Uemura, Motohide; Honma, Seijiro; Chung, Suyoun; Takata, Ryo; Furihata, Mutsuo; Nishimura, Kazuo; Nonomura, Norio; Nasu, Yasutomo; Miki, Tsuneharu; Shuin, Taro; Fujioka, Tomoaki; Okuyama, Akihiko; Nakamura, Yusuke; Nakagawa, Hidewaki

2010-08-01

Prostate cancer often relapses during androgen-depletion therapy, even under the castration condition in which circulating androgens are drastically reduced. High expressions of androgen receptor (AR) and genes involved in androgen metabolism indicate a continued role for AR in castration-resistant prostate cancers (CRPCs). There is increasing evidence that some amounts of 5alpha-dihydrotestosterone (DHT) and other androgens are present sufficiently to activate AR within CRPC tissues, and enzymes involved in the androgen and steroid metabolism, such as 5alpha-steroid reductases, are activated in CRPCs. In this report, we screened eight natural 5alphaDH-steroids to search for novel products of 5alpha-steroid reductases, and identified 11-deoxycorticosterone (DOC) as a novel substrate for 5alpha-steroid reductases in CRPCs. 11-Deoxycorticosterone (DOC) and 5alpha-dihydro-deoxycorticosterone (5alphaDH-DOC) could promote prostate cancer cell proliferation through AR activation, and type 1 5alpha-steroid reductase (SRD5A1) could convert from DOC to 5alphaDH-DOC. Sensitive liquid chromatography-tandem mass spectrometric analysis detected 5alphaDH-DOC in some clinical CRPC tissues. These findings implicated that under an extremely low level of DHT, 5alphaDH-DOC and other products of 5alpha-steroid reductases within CRPC tissues might activate the AR pathway for prostate cancer cell proliferation and survival under castration.

Direct analysis of δ13C and concentration of dissolved organic carbon (DOC) in environmental samples by TOC-IRMS

Science.gov (United States)

Kirkels, Frédérique; Cerli, Chiara; Federherr, Eugen; Kalbitz, Karsten

2014-05-01

Dissolved organic carbon (DOC) plays an important role in carbon cycling in terrestrial and aquatic systems. Stable isotope analysis (delta 13C) of DOC could provide valuable insights in its origin, fluxes and environmental fate. Precise and routine analysis of delta 13C and DOC concentration are therefore highly desirable. A promising, new system has been developed for this purpose, linking a high-temperature combustion TOC analyzer trough an interface with a continuous flow isotope ratio mass spectrometer (Elementar group, Hanau, Germany). This TOC-IRMS system enables simultaneous stable isotope (bulk delta 13C) and concentration analysis of DOC, with high oxidation efficiency by high-temperature combustion for complex mixtures as natural DOC. To give delta 13C analysis by TOC-IRMS the necessary impulse for broad-scale application, we present a detailed evaluation of its analytical performance for realistic and challenging conditions inclusive low DOC concentrations and environmental samples. High precision (standard deviation, SD predominantly TOC-IRMS and conventional EA-IRMS) were achieved by TOC-IRMS for a broad diversity of DOC solutions. This precision is comparable or even slightly better than that typically reported for EA-IRMS systems, and improves previous techniques for δ13C analysis of DOC. Simultaneously, very good precision was obtained for DOC concentration measurements. Assessment of natural abundance and slightly 13C enriched DOC, a wide range of concentrations (0.2-150 mgC/L) and injection volumes (0.05-3 ml), demonstrated good analytical performance with negligible memory effects, no concentration/volume effects and a wide linearity. Low DOC concentrations (TOC-IRMS was successfully applied to analyze DOC from diverse terrestrial, freshwater and marine environments (SD TOC-IRMS performs fast and reliable analysis of DOC concentration and δ13C in aqueous samples, without any pre-concentration/freeze-drying. Flexible usage is highlighted by

Disentangling the influence of environmental and anthropogenic factors on the distribution of endemic vascular plants in Sardinia.

Science.gov (United States)

Fois, Mauro; Fenu, Giuseppe; Cañadas, Eva Maria; Bacchetta, Gianluigi

2017-01-01

Due to the impelling urgency of plant conservation and the increasing availability of high resolution spatially interpolated (e.g. climate variables) and categorical data (e.g. land cover and vegetation type), many recent studies have examined relationships among plant species distributions and a diversified set of explanatory factors; nevertheless, global and regional patterns of endemic plant richness remain in many cases unexplained. One such pattern is the 294 endemic vascular plant taxa recorded on a 1 km resolution grid on the environmentally heterogeneous island of Sardinia. Sixteen predictors, including topographic, geological, climatic and anthropogenic factors, were used to model local (number of taxa inside each 1 km grid cell) Endemic Vascular Plant Richness (EVPR). Generalized Linear Models were used to evaluate how each factor affected the distribution of local EVPR. Significant relationships with local EVPR and topographic, geological, climatic and anthropogenic factors were found. In particular, elevation explained the larger fraction of variation in endemic richness but other environmental factors (e.g. precipitation seasonality and slope) and human-related factors (e.g. the Human Influence Index (HII) and the proportion of anthropogenic land uses) were, respectively, positively and negatively correlated with local EVPR. Regional EVPR (number of endemic taxa inside each 100 m elevation interval) was also measured to compare local and regional EVPR patterns along the elevation gradient. In contrast to local, regional EVPR tended to decrease with altitude partly due to the decreasing area covered along altitude. The contrasting results between local and regional patterns suggest that local richness increases as a result of increased interspecific aggregation along altitude, whereas regional richness may depend on the interaction between area and altitude. This suggests that the shape and magnitude of the species-area relationship might vary with

CDOM fluorescence as a proxy of DOC concentration in natural waters: a comparison of four contrasting tropical systems.

Science.gov (United States)

Rochelle-Newall, E; Hulot, F D; Janeau, J L; Merroune, A

2014-01-01

Chromophoric dissolved organic matter (CDOM) fluorescence or absorption is often proposed as a rapid alternative to chemical methods for the estimation of bulk dissolved organic carbon (DOC) concentration in natural waters. However, the robustness of this method across a wide range of systems remains to be shown. We measured CDOM fluorescence and DOC concentration in four tropical freshwater and coastal environments (estuary and coastal, tropical shallow lakes, water from the freshwater lens of two small islands, and soil leachates). We found that although this method can provide an estimation of DOC concentration in sites with low variability in DOC and CDOM sources in systems where the variability of DOC and CDOM sources are high, this method should not be used as it will lead to errors in the estimation of the bulk DOC concentration.

Cross-scale modelling of alien and native vascular plant species richness in Great Britain: where is geodiversity information most relevant?

Science.gov (United States)

Bailey, Joseph; Field, Richard; Boyd, Doreen

2016-04-01

We assess the scale-dependency of the relationship between biodiversity and novel geodiversity information by studying spatial patterns of native and alien (archaeophytes and neophytes) vascular plant species richness at varying spatial scales across Great Britain. Instead of using a compound geodiversity metric, we study individual geodiversity components (GDCs) to advance our understanding of which aspects of 'geodiversity' are most important and at what scale. Terrestrial native (n = 1,490) and alien (n = 1,331) vascular plant species richness was modelled across the island of Great Britain at two grain sizes and several extent radii. Various GDCs (landforms, hydrology, geology) were compiled from existing national datasets and automatically extracted landform coverage information (e.g. hollows, valleys, peaks), the latter using a digital elevation model (DEM) and geomorphometric techniques. More traditional predictors of species richness (climate, widely-used topography metrics, land cover diversity, and human population) were also incorporated. Boosted Regression Tree (BRT) models were produced at all grain sizes and extents for each species group and the dominant predictors were assessed. Models with and without geodiversity data were compared. Overarching patterns indicated a clear dominance of geodiversity information at the smallest study extent (12.5km radius) and finest grain size (1x1km), which substantially decreased for each increase in extent as the contribution of climatic variables increased. The contribution of GDCs to biodiversity models was chiefly driven by landform information from geomorphometry, but hydrology (rivers and lakes), and to a lesser extent materials (soil, superficial deposits, and geology), were important, also. GDCs added significantly to vascular plant biodiversity models in Great Britain, independently of widely-used topographic metrics, particularly for native species. The wider consideration of geodiversity alongside

panMetaDocs and DataSync - providing a convenient way to share and publish research data

Science.gov (United States)

Ulbricht, D.; Klump, J. F.

2013-12-01

In recent years research institutions, geological surveys and funding organizations started to build infrastructures to facilitate the re-use of research data from previous work. At present, several intermeshed activities are coordinated to make data systems of the earth sciences interoperable and recorded data discoverable. Driven by governmental authorities, ISO19115/19139 emerged as metadata standards for discovery of data and services. Established metadata transport protocols like OAI-PMH and OGC-CSW are used to disseminate metadata to data portals. With the persistent identifiers like DOI and IGSN research data and corresponding physical samples can be given unambiguous names and thus become citable. In summary, these activities focus primarily on 'ready to give away'-data, already stored in an institutional repository and described with appropriate metadata. Many datasets are not 'born' in this state but are produced in small and federated research projects. To make access and reuse of these 'small data' easier, these data should be centrally stored and version controlled from the very beginning of activities. We developed DataSync [1] as supplemental application to the panMetaDocs [2] data exchange platform as a data management tool for small science projects. DataSync is a JAVA-application that runs on a local computer and synchronizes directory trees into an eSciDoc-repository [3] by creating eSciDoc-objects via eSciDocs' REST API. DataSync can be installed on multiple computers and is in this way able to synchronize files of a research team over the internet. XML Metadata can be added as separate files that are managed together with data files as versioned eSciDoc-objects. A project-customized instance of panMetaDocs is provided to show a web-based overview of the previously uploaded file collection and to allow further annotation with metadata inside the eSciDoc-repository. PanMetaDocs is a PHP based web application to assist the creation of metadata in

Winter Ground Temperatures Control Snowmelt DOC Export From a Discontinuous Permafrost Watershed: A Multi-Year Perspective

Science.gov (United States)

Carey, S. K.

2006-12-01

For discontinuous and continuous permafrost watersheds, the largest mass flux of dissolved organic carbon (DOC) occurs during the snowmelt period. During this time, available allochtonous organic carbon that has accumulated over the winter in frozen organic soils is rapidly flushed to the basin outlet. While this process has been observed now in many river systems of different size and location, there have been few inter-annual reports on the mass of DOC loss and the factors controlling its variability during freshet. Hydrological and DOC fluxes were recorded for the 2002, 2003 and 2006 snowmelt season with supplementary over-winter data for an 8 square kilometer sub-basin (Granger Basin) of the Wolf Creek Research Basin, Yukon Territory, Canada. Granger Basin is an alpine catchment above treeline underlain with discontinuous permafrost (approximately 70 %) and has widespread surface organic soils up to 0.4 m in thickness. Pre-melt snow water equivalent varied widely throughout the basin, yet was greatest in 2006, followed by 2002 and 2003. Ground temperatures were notably colder throughout the 2003 winter compared with 2006 and 2002. For all years, discharge began in mid-May, and was a continuous event in 2002 and 2006. In 2003 four distinct melt-periods were observed due to rising and falling temperatures. During freshet, stream DOC concentration increased rapidly from 15 mg C/L on the first ascending limb of the hydrograph in each year. In 2003, DOC was largely flushed from the catchment several weeks prior to peak freshet. DOC concentration in wells and piezometers followed a similar pattern to streamflow DOC, with 2003 groundwater DOC concentrations less than 2002 and 2006. The total mass flux of DOC during freshet was 0.85, 0.45 and 1.01 g C/m2 for 2002, 2003 and 2006 respectively. Despite differences in pre-melt snow accumulation, the timing of melt and the volume of discharge, it appears that spring DOC export is largely controlled by over-winter ground

Contrasts between bryophyte and vascular plant synecological responses in an SO/sub 2/-stressed white spruce association in Central Alberta

Energy Technology Data Exchange (ETDEWEB)

Winner, W.E.; Bewley, J.D.

1978-01-01

Canopy coverage analysis was used to examine the synecological changes exhibited by vascular plants and terrestrial mosses in a white spruce association exposed to SO/sub 2/ fumigation. Both these understory components were found to decline in coverage as SO/sub 2/ stress increased, but mosses were more sensitive to SO/sub 2/ in the more heavily stressed areas. This was observed along both an angle-dependent and a distance-dependent gradient of pollution stress. Diversity steadily declined with increasing SO/sub 2/ stress along the angle-dependent gradient but some localized increases in diversity occurred with increasing stress along the distance-dependent gradient. This was due to invasion of openings resulting from attrition of SO/sub 2/-sensitive species by weedy angiosperms and by vegetative growth of moss species more tolerant of pollution stress. Conclusions have been drawn about the productive strategy of vascular plants and mosses subjected to increasing concentrations of SO/sub 2/. We have elucidated the ecological consequences for community structure of the systematic removal of pollution-sensitive understory species from an otherwise stable vegetation unit.

Does cross-taxon analysis show similarity in diversity patterns between vascular plants and bryophytes? Some answers from a literature review.

Science.gov (United States)

Bagella, Simonetta

2014-04-01

The objective of this study was to clarify the taxon surrogacy hypothesis relative to vascular plants and bryophytes. A literature review was conducted to obtain papers that met the following criteria: (i) they examined species richness values; or (ii) they evaluated the species richness within the same study sites, or under the same spatial variation conditions. Twenty-seven papers were accessed. The richness of the two taxa, compared in 32 cases, positively co-varied in about half of the comparisons. The response to the spatial variation in environmental or human-induced factors of the two taxa in terms of species richness was rather variable. Based on current knowledge, the main documented findings regard forest habitats and nival gradients. In forest habitats, co-variation in species richness is likely when similar environments are analysed and seems to be strengthened for boreal forests. Along the nival gradient, a different response in terms of richness of the two taxa suggests that vascular plants cannot be considered good surrogates for bryophytes. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

G-DOC: A Systems Medicine Platform for Personalized Oncology1

Science.gov (United States)

Madhavan, Subha; Gusev, Yuriy; Harris, Michael; Tanenbaum, David M; Gauba, Robinder; Bhuvaneshwar, Krithika; Shinohara, Andrew; Rosso, Kevin; Carabet, Lavinia A; Song, Lei; Riggins, Rebecca B; Dakshanamurthy, Sivanesan; Wang, Yue; Byers, Stephen W; Clarke, Robert; Weiner, Louis M

2011-01-01

Currently, cancer therapy remains limited by a “one-size-fits-all” approach, whereby treatment decisions are based mainly on the clinical stage of disease, yet fail to reference the individual's underlying biology and its role driving malignancy. Identifying better personalized therapies for cancer treatment is hindered by the lack of high-quality “omics” data of sufficient size to produce meaningful results and the ability to integrate biomedical data from disparate technologies. Resolving these issues will help translation of therapies from research to clinic by helping clinicians develop patient-specific treatments based on the unique signatures of patient's tumor. Here we describe the Georgetown Database of Cancer (G-DOC), a Web platform that enables basic and clinical research by integrating patient characteristics and clinical outcome data with a variety of high-throughput research data in a unified environment. While several rich data repositories for high-dimensional research data exist in the public domain, most focus on a single-data type and do not support integration across multiple technologies. Currently, G-DOC contains data from more than 2500 breast cancer patients and 800 gastrointestinal cancer patients, G-DOC includes a broad collection of bioinformatics and systems biology tools for analysis and visualization of four major “omics” types: DNA, mRNA, microRNA, and metabolites. We believe that G-DOC will help facilitate systems medicine by providing identification of trends and patterns in integrated data sets and hence facilitate the use of better targeted therapies for cancer. A set of representative usage scenarios is provided to highlight the technical capabilities of this resource. PMID:21969811

A systematic examination of the relationships between CDOM and DOC in inland waters in China

Directory of Open Access Journals (Sweden)

K. Song

2017-10-01

Full Text Available Chromophoric dissolved organic matter (CDOM plays a vital role in the biogeochemical cycle in aquatic ecosystems. The relationship between CDOM and dissolved organic carbon (DOC has been investigated, and this significant relationship lays the foundation for the estimation of DOC using remotely sensed imagery data. The current study examined samples from freshwater lakes, saline lakes, rivers and streams, urban water bodies, and ice-covered lakes in China for tracking the variation of the relationships between DOC and CDOM. The regression model slopes for DOC vs. aCDOM (275 ranged from extremely low 0.33 (highly saline lakes to 1.03 (urban waters and 3.01 (river waters. The low values were observed in saline lake waters and waters from semi-arid or arid regions, where strong photobleaching is expected due to less cloud cover, longer water residence time, and daylight hours. In contrast, high values were found in waters developed in wetlands or forest in Northeast China, where more organic matter was transported from catchment to waters. The study also demonstrated that closer relationships between CDOM and DOC were revealed when aCDOM (275 were sorted by the ratio of aCDOM(250∕aCDOM (365, which is a measure for the CDOM absorption with respect to its composition, and the determination of coefficient of the regression models ranged from 0.79 to 0.98 for different groups of waters. Our results indicate the relationships between CDOM and DOC are variable for different inland waters; thus, models for DOC estimation through linking with CDOM absorption need to be tailored according to water types.

Role of endophytic fungi in the migration of the radionuclides in the vascular plants of the Ukrainian Polesye sphagniopratum

International Nuclear Information System (INIS)

Zhdanova, N.N.; Sokolova, E.V.; Kurchenko, I.N.; Orlov, A.A.

2002-01-01

It is known that the specific activity of 137 Cs in vegetative phytomass of cranberry and sphagnum in oligotrophic conditions of Ukrainian Polessye forest sphagniopratum amounts 5000 - 10000 Bq/kg of air-dry weight. Roots of cranberry in natural conditions never run up to peat and mainly are located in top layer of the sphagnum top which is sodden by a water, but specific activity of the radionuclide in swamp water is low (2 - 10 Bq/l). It was supposed that mycorrhizal and endophytic micromycetes take an essential part in transferring the mineral substances and 137 Cs from sphagnum mosses to ericoid plants under oligotrophic swamp conditions. Endophytic fungi from vascular plants were not investigated in Ukraine. The article is devoted to the estimation of distribution of endophytic fungi in plants which are dominants of the plant cover of sphagniopratum. 47 species of micromycetes which belong to 27 genera were identified. For moss and ericoid plants five mutual species of endophytic fungi was detected

The Fic protein Doc uses an inverted substrate to phosphorylate and inactivate EF-Tu.

Science.gov (United States)

Castro-Roa, Daniel; Garcia-Pino, Abel; De Gieter, Steven; van Nuland, Nico A J; Loris, Remy; Zenkin, Nikolay

2013-12-01

Fic proteins are ubiquitous in all of the domains of life and have critical roles in multiple cellular processes through AMPylation of (transfer of AMP to) target proteins. Doc from the doc-phd toxin-antitoxin module is a member of the Fic family and inhibits bacterial translation by an unknown mechanism. Here we show that, in contrast to having AMPylating activity, Doc is a new type of kinase that inhibits bacterial translation by phosphorylating the conserved threonine (Thr382) of the translation elongation factor EF-Tu, rendering EF-Tu unable to bind aminoacylated tRNAs. We provide evidence that EF-Tu phosphorylation diverged from AMPylation by antiparallel binding of the NTP relative to the catalytic residues of the conserved Fic catalytic core of Doc. The results bring insights into the mechanism and role of phosphorylation of EF-Tu in bacterial physiology as well as represent an example of the catalytic plasticity of enzymes and a mechanism for the evolution of new enzymatic activities.

The eDoc-Server Project Building an Institutional Repository for the Max Planck Society

CERN Document Server

Beier, Gerhard

2004-01-01

With the eDoc-Server the Heinz Nixdorf Center for Information Management in the Max Planck Society (ZIM) provides the research institutes of the Max Planck Society (MPS) with a platform to disseminate, store, and manage their scientific output. Moreover, eDoc serves as a tool to facilitate and promote open access to scientific information and primary sources. Since its introduction in October 2002 eDoc has gained high visibility within the MPS. It has been backed by strong institutional commitment to open access as documented in the 'Berlin Declaration on Open Access to the Data of the Sciences and Humanities', which was initiated by the MPS and found large support among major research organizations in Europe. This paper will outline the concept as well as the current status of the eDoc-Server, providing an example for the development and introduction of an institutional repository in a multi-disciplinary research organization.

A mobile water analysis laboratory for the study of stream nutrient and DOC dynamics

Science.gov (United States)

Echevarria Roman, Y.; Pullin, M. J.; Schwingle, R.; Gabrielsen, P. J.

2013-12-01

The dynamics of nutrient and dissolved organic carbon (DOC) quantity and composition in streams vary with season and in response to hydrologic events. Periodic grab sampling can capture some of this variation, but has also been shown to miss high flow events. Sampling during winter, during thunderstorms, and at night is difficult and sometimes hazardous. For these reasons, we have developed a mobile laboratory that autonomously determines pH, Eh, conductivity, dissolved oxygen, turbidity, nitrate, phosphate, DOC, DIC, as well as DOC fluorescence and absorbance continuously on a minutes timescale. The laboratory includes a Labview operated computer system that allows remote control and interaction with pumps, pressure, temperature, and flow sensors as well as the analytical instruments. Climate control allows for operation in winter. The design and operation of this laboratory will be presented. We will also discuss example data showing diurnal changes and responses to hydrologic events in DOC quantity and quality in the East Fork of the Jemez River, New Mexico.

The role of hydrologic regimes on dissolved organic carbon composition in an agricultural watershed

Science.gov (United States)

Hernes, P.J.; Spencer, R.G.M.; Dyda, R.Y.; Pellerin, B.A.; Bachand, P.A.M.; Bergamaschi, B.A.

2008-01-01

Willow Slough, a seasonally irrigated agricultural watershed in the Sacramento River valley, California, was sampled weekly in 2006 in order to investigate seasonal concentrations and compositions of dissolved organic carbon (DOC). Average DOC concentrations nearly doubled from winter baseflow (2.75 mg L-1) to summer irrigation (5.14 mg L-1), while a concomitant increase in carbon-normalized vanillyl phenols (0.11 mg 100 mg OC-1 increasing to 0.31 mg 100 mg OC-1, on average) indicates that this additional carbon is likely vascular plant-derived. A strong linear relationship between lignin concentration and total suspended sediments (r2 = 0.79) demonstrates that agricultural management practices that mobilize sediments will likely have a direct and significant impact on DOC composition. The original source of vascular plant-derived DOC to Willow Slough appears to be the same throughout the year as evidenced by similar syringyl to vanillyl and cinnamyl to vanillyl ratios. However, differing diagenetic pathways during winter baseflow as compared to the rest of the year are evident in acid to aldehyde ratios of both vanillyl and syringyl phenols. The chromophoric dissolved organic matter (CDOM) absorption coefficient at 350 nm showed a strong correlation with lignin concentration (r2 = 0.83). Other CDOM measurements related to aromaticity and molecular weight also showed correlations with carbon-normalized yields (e.g. specific UV absorbance at 254 nm (r2 = 0.57) and spectral slope (r2 = 0.54)). Our overall findings suggest that irrigated agricultural watersheds like Willow Slough can potentially have a significant impact on mainstem DOC concentration and composition when scaled to the entire watershed of the main tributary. ?? 2008 Elsevier Ltd.

The role of hydrologic regimes on dissolved organic carbon composition in an agricultural watershed

Science.gov (United States)

Hernes, Peter J.; Spencer, Robert G. M.; Dyda, Rachael Y.; Pellerin, Brian A.; Bachand, Philip A. M.; Bergamaschi, Brian A.

2008-11-01

Willow Slough, a seasonally irrigated agricultural watershed in the Sacramento River valley, California, was sampled weekly in 2006 in order to investigate seasonal concentrations and compositions of dissolved organic carbon (DOC). Average DOC concentrations nearly doubled from winter baseflow (2.75 mg L -1) to summer irrigation (5.14 mg L -1), while a concomitant increase in carbon-normalized vanillyl phenols (0.11 mg 100 mg OC -1 increasing to 0.31 mg 100 mg OC -1, on average) indicates that this additional carbon is likely vascular plant-derived. A strong linear relationship between lignin concentration and total suspended sediments ( r2 = 0.79) demonstrates that agricultural management practices that mobilize sediments will likely have a direct and significant impact on DOC composition. The original source of vascular plant-derived DOC to Willow Slough appears to be the same throughout the year as evidenced by similar syringyl to vanillyl and cinnamyl to vanillyl ratios. However, differing diagenetic pathways during winter baseflow as compared to the rest of the year are evident in acid to aldehyde ratios of both vanillyl and syringyl phenols. The chromophoric dissolved organic matter (CDOM) absorption coefficient at 350 nm showed a strong correlation with lignin concentration ( r2 = 0.83). Other CDOM measurements related to aromaticity and molecular weight also showed correlations with carbon-normalized yields (e.g. specific UV absorbance at 254 nm ( r2 = 0.57) and spectral slope ( r2 = 0.54)). Our overall findings suggest that irrigated agricultural watersheds like Willow Slough can potentially have a significant impact on mainstem DOC concentration and composition when scaled to the entire watershed of the main tributary.

Local and regional scale exchanges of dissolved organic carbon (DOC) between tidal wetlands and their adjacent coastal waters

Science.gov (United States)

Osburn, C. L.; Joshi, I.; Lebrasse, M. C.; Oviedo-Vargas, D.; Bianchi, T. S.; Bohnenstiehl, D. R.; D'Sa, E. J.; He, R.; Ko, D.; Arellano, A.; Ward, N. D.

2017-12-01

The contribution of blue carbon from tidal wetlands to the coastal ocean in the form of dissolved organic carbon (DOC) represents a terrestrial-aquatic linkage of increasing importance. DOC flux results will be presented from local (tidal creek) and regional (bays) scale studies in which various combinations of field observations, ocean-color satellite observations, and the outputs of high-resolution hydrodynamic models were used to estimate DOC export. The first project was located in Bald Head Creek, a tributary to the Cape Fear River estuary in eastern North Carolina (NC). DOC fluxes were computed using a bathymetric data collected via unmanned surface vehicle (USV) and a numerical hydrodynamic model (SCHISM) based on the relationships between colored dissolved organic matter (CDOM) absorption, DOC concentration, and salinity taken from field observations. Model predictions estimated an annual net export of DOC at 54 g C m-2 yr-1 from the tidal creek to the adjacent estuary. Carbon stable isotope (δ13C) values were used to estimate the contribution of wetland carbon to this export. In the second project, DOC fluxes from the Apalachicola Bay, FL, Barataria Bay, LA, were based on the development of algorithms between DOC and CDOM absorption derived from the VIIRS ocean color sensor. The Navy Coastal Ocean Model (NCOM) was used to compute salt flux estimates from each bay to the Louisiana-Texas shelf. The relationship between salinity and CDOM was used to estimate net annual DOC exports of 8.35 x 106 g C m-2 y-1 (Apalachicola Bay) and 7.14 x 106 g C m-2 yr-1 (Barataria Bay). These values approximate 13% and 9% of the annual loads of DOC from the Mississippi River to the Gulf of Mexico, respectively. CDOM and lignin were used in a mixing model to estimate wetland-derived DOC were 2% for Apalachicola Bay and 13% for Barataria Bay, the latter having one of the highest rates of relative sea level rise in North America. Results from our project demonstrated the utility

Characterisation of DOC and its relation to the deep terrestrial biosphere

Science.gov (United States)

Vieth, Andrea; Vetter, Alexandra; Sachse, Anke; Horsfield, Brian

2010-05-01

The deep subsurface is populated by a large number of microorganisms playing a pivotal role in the carbon cycling. The question arises as to the origin of the potential carbon sources that support deep microbial communities and their possible interactions within the deep subsurface. As the carbon sources need to be dissolved in formation fluids to become available to microorganisms, the dissolved organic carbon (DOC) needs further characterisation as regards concentration, structural as well as molecular composition and origin. The Malm carbonates in the Molasse basin of southern Germany are of large economic potential as they are targets for both hydrocarbon and geothermal exploration (ANDREWS et al., 1987). Five locations that differ in their depth of the Malm aquifer between 220 m and 3445 m below surface have been selected for fluid sampling. The concentration and the isotopic composition of the DOC have been determined. To get a better insight into the structural composition of the DOC, we also applied size exclusion chromatography and quantified the amount of low molecular weight organic acids (LMWOA) by ion chromatography. With increasing depth of the aquifer the formation fluids show increasing salinity as chloride concentrations increase from 2 to 300 mg/l and also the composition of the DOC changes. Water samples from greater depth (>3000 m) showed that the DOC mainly consists of LMWOA (max. 83 %) and low percentages of neutral compounds (alcohols, aldehyde, ketones, amino acids) as well as "building blocks". Building blocks have been described to be the oxidation intermediates from humic substances to LMWOA. With decreasing depth of the aquifer, the DOC of the fluid becomes increasingly dominated by neutral compounds and the percentage of building blocks increases to around 27%. The fluid sample from 220 m depth still contains a small amount of humic substances. The DOC of formation fluids in some terrestrial sediments may originate from organic

Does wildfire cause cascading effects on aquatic C cycling? A study of soil, well and lake DOC composition and bio/photolability

Science.gov (United States)

Olefeldt, D.; Turetsky, M. R.; Devito, K. J.; Blodau, C.

2012-12-01

In May 2011 a wildfire broke out north of Utikuma Lake in central Alberta, Canada, which eventually burned an area of ~880 km2. Wildfire alters soil properties, potentially altering the chemical composition of terrestrial DOC that reaches downstream aquatic environments. In order to study the potential effects of wildfire on lake carbon cycling, we sampled and incubated DOC from soil samples (n=52), wells (n=35) and lakes (n=32) from within and outside the recent fire perimeter. We incubated the DOC samples under both dark and UV conditions to assess both bio- and photolability, and followed DOC composition throughout the incubations by measuring DOC absorbing and fluorescing properties. A strong effect of wildfire was found among DOC samples leached from surface peatland and upland soils - with fire yielding increased DOC aromaticity associated with decreased biodegradability but also increased photolability. Parallel factor analysis of fluorescence matrices revealed distinct regions that were associated with DOC leached from charred soils, potentially linked to their lower biodegradability. Dark and UV conditions gave rise to very different trajectories of changes to DOC composition throughout incubations, with preferential losses of non-aromatic DOC under dark conditions and aromatic DOC under UV conditions. The DOC composition index that was found to best predict both DOC bio- and photolability was specific UV absorbance, which is also a very simple and quick index to measure. For lakes, we found that the primary influences on DOC composition and bio-/photolability was linked to lake size and hydrogeological setting (whether located on a lacustrine clay plain or in a moraine/outwash region) that controls groundwater influence and the hydrological connectivity to adjacent peatlands. Further analysis of well and lake water incubations will be used to detect whether wildfire can be detected to have a subtle secondary effect on DOC composition and lability or if

48 CFR 1335.016-70 - DOC procedures for the use of broad agency announcements.

Science.gov (United States)

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false DOC procedures for the use of broad agency announcements. 1335.016-70 Section 1335.016-70 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE SPECIAL CATEGORIES OF CONTRACTING RESEARCH AND DEVELOPMENT CONTRACTING 1335.016-70 DOC...

Effect of light and nutrient availability on the release of dissolved organic carbon (DOC) by Caribbean turf algae

NARCIS (Netherlands)

Mueller, B.; den Haan, J.; Visser, P.M.; Vermeij, M.J.A.; van Duyl, F.C.

2016-01-01

Turf algae increasingly dominate benthic communities on coral reefs. Given their abundance and high dissolved organic carbon (DOC) release rates, turf algae are considered important contributors to the DOC pool on modern reefs. The release of photosynthetically fixed carbon as DOC generally, but not

Long-term changes in acidity and DOC in throughfall and soil water in Finnish forests.

Science.gov (United States)

Ukonmaanaho, Liisa; Starr, Mike; Lindroos, Antti-Jussi; Nieminen, Tiina M

2014-11-01

The main objective of this study was to examine if any detectable trends in dissolved organic carbon (DOC), sulphate (SO4-S) concentrations and acid neutralizing capacity (ANC) in throughfall (TF) and soil water (SW) could be found during 1990-2010 and to relate them to recent changes in decreased acid deposition. The study was conducted in seven boreal coniferous forest sites: four of which are managed and three unmanaged forests sites. Generally, temporal trend showed a significant decrease in SO4-S concentrations in bulk precipitation (BP), TF and SW. At some of the sites, there was an increasing tendency in BP and TF in the DOC concentrations. This feature coincides with decreasing SO4-S concentration, indicating that SO4-S may be an important driver of DOC release from the canopy. However, a slightly increased temperature, larger senescing needle mass and consequently increased decaying activity in the canopy may partly explain the increasing trend in DOC. In SW, no consistent DOC trend was seen. At some sites, the decreased base cation concentrations mostly account for the decrease in the ANC values in SW and TF.

Aging and temperature effects on DOC and elemental release from a metal contaminated soil

International Nuclear Information System (INIS)

Martinez, C.E.; Jacobson, A.R.; McBride, M.B.

2003-01-01

Increased aging and temperatures may affect DOC element complexes and their release. - The combined effect of time and temperature on elemental release and speciation from a metal contaminated soil (Master Old Site, MOS) was investigated. The soil was equilibrated at 10, 28, 45, 70 and 90 deg. C for 2 days, 2 weeks, and 2 months in the laboratory. Dissolved organic carbon (DOC), total soluble elements (by ICP), and labile metals (by DPASV) were determined in the filtered (0.22 μm) supernatants. For the samples equilibrated at 90 deg. C, DOC fractions were size fractionated by filtration and centrifugation; a subsample was only centrifuged while another was also filtered through a 0.45 μm filter. Analyses of the supernatants (ICP, DPASV, DOC) were performed on all size fraction subsamples. Dissolved organic carbon (DOC) increased both with temperature and incubation time; however, metal behavior was not as uniform. In general, total soluble metal release (ICP) paralleled the behavior of DOC, increasing with both time and temperature, and confirming the importance of soil organic matter (SOM) in metal retention. Voltammetric analysis (dpasv) of Cu and Zn showed that very little of these metals remains labile in solution due, presumably, to complexation with dissolved organic matter. Labile concentrations of Cd, on the other hand, constituted a significant portion (50%) of total soluble Cd. Copper and Al increased in solution with time (up to 2 months) and temperature up to 70 deg. C; however, at 90 deg. C the soluble concentration declined sharply. The same behavior was observed after equilibration for longer periods of time (550 days) at lower temperatures (23 and 70 deg. C). While concentrations of labile Cu and total soluble Cu and Al increased in the unfiltered samples, the trend remained the same. DPASV analysis showing shifts in labile Cu complexes with temperature and time, together with the results from the unfiltered samples, lead to the hypothesis that Cu

Disentangling environmental correlates of vascular plant biodiversity in a Mediterranean hotspot.

Science.gov (United States)

Molina-Venegas, Rafael; Aparicio, Abelardo; Pina, Francisco José; Valdés, Benito; Arroyo, Juan

2013-10-01

We determined the environmental correlates of vascular plant biodiversity in the Baetic-Rifan region, a plant biodiversity hotspot in the western Mediterranean. A catalog of the whole flora of Andalusia and northern Morocco, the region that includes most of the Baetic-Rifan complex, was compiled using recent comprehensive floristic catalogs. Hierarchical cluster analysis (HCA) and detrended correspondence analysis (DCA) of the different ecoregions of Andalusia and northern Morocco were conducted to determine their floristic affinities. Diversity patterns were studied further by focusing on regional endemic taxa. Endemic and nonendemic alpha diversities were regressed to several environmental variables. Finally, semi-partial regressions on distance matrices were conducted to extract the respective contributions of climatic, altitudinal, lithological, and geographical distance matrices to beta diversity in endemic and nonendemic taxa. We found that West Rifan plant assemblages had more similarities with Andalusian ecoregions than with other nearby northern Morocco ecoregions. The endemic alpha diversity was explained relatively well by the environmental variables related to summer drought and extreme temperature values. Of all the variables, geographical distance contributed by far the most to spatial turnover in species diversity in the Baetic-Rifan hotspot. In the Baetic range, elevation was the most significant driver of nonendemic species beta diversity, while lithology and elevation were the main drivers of endemic beta diversity. Despite the fact that Andalusia and northern Morocco are presently separated by the Atlantic Ocean and the Mediterranean Sea, the Baetic and Rifan mountain ranges have many floristic similarities - especially in their western ranges - due to past migration of species across the Strait of Gibraltar. Climatic variables could be shaping the spatial distribution of endemic species richness throughout the Baetic-Rifan hotspot. Determinants

Hydrologic and forest management controls on DOC dynamics in the small watersheds of the H.J. Andrews Experimental Forest, OR

Science.gov (United States)

Lajtha, K.; Jones, J. A.

2016-12-01

Dissolved organic carbon (DOC) export from hillslopes to streams is an important component of the carbon cycle of a catchment and may be a critical source of energy for the aquatic food web in receiving waters. Using a long-term record of DOC and other dissolved nutrients and elements from paired watersheds from the H.J. Andrews Experimental Forest in Oregon, we explored hydrologic, climatic, and land-use controls on seasonal and inter-annual patterns of DOC flux in a seasonally dry ecosystem. Seasonal patterns of DOC flux demonstrated source limitations to DOC export, with DOC concentrations highest immediately following the first rains after a dry summer, and lowest after winter rains. In contrast, more geochemically-controlled elements showed simple dilution-concentration patterns with no seasonal hysteresis. Inter-annual patterns of DOC flux, however, did not provide evidence of source limitation, with DOC flux within a watershed tightly correlated to total discharge but not temperature. Among watersheds, forest harvest, even over 50 years ago, significantly reduced DOC flux but not fluxes of other elements including N; this response was linked to the loading of coarse woody debris to the forest floor. Chemical fingerprinting of DOC revealed that old-growth watersheds had higher fluxes of DOC characteristic of forest floor organic materials, likely delivered to streams through more surficial preferential flow pathways not subject to microbial alteration, respiration, or sorption losses. Taken together these results suggest that the biogeochemical composition of forested streams reflects both current hydrologic patterns and also processes that occurred many decades ago within the catchment.

Diurnal and seasonal DOC and POC variability in the land-locked sea

Directory of Open Access Journals (Sweden)

Beata Szymczycha

2017-07-01

Full Text Available Organic matter is a minor yet important component of the marine environment. The aim of this study was to investigate the diurnal and seasonal changes in dissolved and particulate organic carbon (DOC and POC, respectively. Thus, DOC and POC as well as chlorophyll a (Chl a, δ13C, NO3−, NO2−, NH4+, PO43−, salinity, pH, and temperature were regularly measured in samples collected for 24 h (2-h resolution in the Gdańsk Deep (54°44.730′N, 19°08.531′E at three water depths (1, 10, and 40 m during sampling campaigns in 2011 (May, 2014 (May, and 2015 (January, March, May, July, September, November. Seasonal variations in DOC and POC followed the seasonality of Chl a (proportional trend and nutrients (reverse trend concentrations. Diurnal oscillations were detected in six out of the eight measurement series. The strongest diurnal variability in both POC and DOC occurred in May 2011 and March 2015, when phytoplankton activity was highest (high Chl a. The surprisingly low δ13C values (range: −28‰ to −24‰ measured over the course of the study revealed the gaps in our knowledge of the isotopic characteristics of terrestrial- vs. marine-derived particulate organic matter.

Radiocarbon measurements of dissolved organic carbon in sewage-treatment-plant effluent and domestic sewage

International Nuclear Information System (INIS)

Nara, Fumiko Watanabe; Imai, Akio; Matsushige, Kazuo; Komatsu, Kazuhiro; Kawasaki, Nobuyuki; Shibata, Yasuyuki

2010-01-01

In an attempt to better characterize dissolved organic carbon (DOC) in several specific sources to Lake Kasumigaura, such as sewage-treatment-plant effluent (STPE), domestic sewage (DS) and forest stream (FS), we analyzed radiocarbon ( 14 C) and stable carbon isotopic compositions ( 13 C) of the DOCs. The measurements of 14 C for DOC were performed by an accelerator mass spectrometer (AMS) at the National Institute for Environmental Studies (NIES-TERRA) in Japan. The Δ 14 C and δ 13 C values of the DOCs in several sources to Lake Kasumigaura, have low carbon isotopic values, ranging from -470 per mille to -79 per mille and from -27.9 per mille to -24.2 per mille , respectively. These carbon isotopic values are substantially different from those of Lake Kasumigaura. These results imply different origins for the DOC in Lake Kasumigaura. The 14 C and 13 C analyses of DOC led to a useful classification for DOCs in Lake Kasumigaura, Japan.

Declines in the dissolved organic carbon (DOC) concentration and flux from the UK

Science.gov (United States)

Worrall, Fred; Howden, Nicholas J. K.; Burt, Tim P.; Bartlett, Rebecca

2018-01-01

Increased concentrations of dissolved organic carbon (DOC) have been reported for many catchments across the northern hemisphere. Hypotheses to explain the increase have varied (eg. increasing air temperature or recovery from acidification) but one test of alternative hypotheses is the trend over the recent decade, with the competing hypotheses predicting: continuing increase; the rate of increase declining with time; and even decrease in concentration. In this study, records of DOC concentration in non-tidal rivers across the UK were examined for the period 2003-2012. The study found that: Of the 62 decade-long concentration trends that could be examined, 3 showed a significant increase, 17 experienced no significant change and 42 showed a significant decrease; in 28 of the 42 significant decreases, a significant step change was apparent with step changes being a decrease in concentration in every case. Of the 118 sites where annual flux and concentration records were available from 1974, 28 showed a significant step change down in flux and 52 showed a step down in concentration. The modal year of the step changes was 2000 with no step changes observed before 1982. At the UK national scale, DOC flux peaked in 2005 at 1354 ktonnes C/yr (5.55 tonnes C/km2/yr) but has declined since. The study suggests that there is a disconnection between DOC records from large catchments at their tidal limits and complementary records from headwater catchments, which means that mechanisms believed to be driving increases in DOC concentrations in headwaters will not necessarily be those controlling trends in DOC concentration further downstream. We propose that the changes identified here have been driven by changes in in-stream processing and changes brought about by the Urban Waste Water Treatment Directive. Therefore, signals identified in headwater catchments may bear little relation to those observed in large rivers much further downstream and vice versa.

The role of forest type in the variability of DOC in atmospheric deposition at forest plots in Italy.

Science.gov (United States)

Arisci, S; Rogora, M; Marchetto, A; Dichiaro, F

2012-06-01

Dissolved organic carbon (DOC) was studied in atmospheric deposition samples collected on a weekly basis in 2005-2009 at 10 forest plots in Italy. The plots covered a wide range of geographical attributes and were representative of the main forest types in Italy. Both spatial and temporal variations in DOC concentrations and fluxes are discussed, with the aim of identifying the main factors affecting DOC variability. DOC concentration increased from bulk to throughfall and stemflow water samples at all sites, as an effect of leaching from leaves and branches, going from 0.7-1.7 mg C L(-1) in bulk samples to 1.8-15.8 mg C L(-1) in throughfall and 4.2-10.7 mg C L(-1) in stemflow, with striking differences among the various plots. Low concentrations were found in runoff (0.5-2.0 mg C L(-1)), showing that the export of DOC via running waters was limited. The seasonality of DOC in throughfall samples was evident, with the highest concentration in summer when biological activity is at a maximum, and minima in winter due to limited DOC production and leaching. Statistical analysis revealed that DOC had a close relationship with organic and total nitrogen, and with nutrient ions, and a negative correlation with precipitation amount. Forest type proved to be a major factor affecting DOC variability: concentration and, to a lesser extent, fluxes were lower in stands dominated by deciduous species. The character of evergreens, and the size and shape of their leaves and needles, which regulate the interception mechanism of dry deposition, are mainly responsible for this.

Vascular Plant and Vertebrate Inventory of Montezuma Castle National Monument

Science.gov (United States)

Schmidt, Cecilia A.; Drost, Charles A.; Halvorson, William Lee

2006-01-01

Executive Summary We summarize past inventory efforts for vascular plants and vertebrates at Montezuma Castle National Monument (NM) in Arizona. We used data from previous research to compile complete species lists for the monument and to assess inventory completeness. There have been 784 species recorded at Montezuma Castle NM, of which 85 (11%) are non-native. In each taxon-specific chapter we highlight areas of resources that contributed to species richness or unique species for the monument. Of particular importance are Montezuma Well and Beaver and Wet Beaver creeks and the surrounding riparian vegetation, which are responsible for the monument having one of the highest numbers of bird species in the Sonoran Desert Network of park units. Beaver Creek is also home to populations of federally-listed fish species of concern. Other important resources include the cliffs along the creeks and around Montezuma Well (for cliff and cave roosting bats). Based on the review of past studies, we believe the inventory for most taxa is nearly complete, though some rare or elusive species will be added with additional survey effort. We recommend additional inventory, monitoring and research studies.

Impact of catchment geophysical characteristics and climate on the regional variability of dissolved organic carbon (DOC) in surface water.

Science.gov (United States)

Cool, Geneviève; Lebel, Alexandre; Sadiq, Rehan; Rodriguez, Manuel J

2014-08-15

Dissolved organic carbon (DOC) is a recognized indicator of natural organic matter (NOM) in surface waters. The aim of this paper is twofold: to evaluate the impact of geophysical characteristics, climate and ecological zones on DOC concentrations in surface waters and, to develop a statistical model to estimate the regional variability of these concentrations. In this study, multilevel statistical analysis was used to achieve three specific objectives: (1) evaluate the influence of climate and geophysical characteristics on DOC concentrations in surface waters; (2) compare the influence of geophysical characteristics and ecological zones on DOC concentrations in surface waters; and (3) develop a model to estimate the most accurate DOC concentrations in surface waters. The case study involved 115 catchments from surface waters in the Province of Quebec, Canada. Results showed that mean temperatures recorded 60 days prior to sampling, total precipitation 10 days prior to sampling and percentages of wetlands, coniferous forests and mixed forests have a significant positive influence on DOC concentrations in surface waters. The catchment mean slope had a significant negative influence on DOC concentrations in surface waters. Water type (lake or river) and deciduous forest variables were not significant. The ecological zones had a significant influence on DOC concentrations. However, geophysical characteristics (wetlands, forests and slope) estimated DOC concentrations more accurately. A model describing the variability of DOC concentrations was developed and can be used, in future research, for estimating DBPs in drinking water as well evaluating the impact of climate change on the quality of surface waters and drinking water. Copyright © 2014 Elsevier B.V. All rights reserved.

Overexpression of DOC-1R inhibits cell cycle G1/S transition by repressing CDK2 expression and activation.

Science.gov (United States)

Liu, Qi; Liu, Xing; Gao, Jinlan; Shi, Xiuyan; Hu, Xihua; Wang, Shusen; Luo, Yang

2013-01-01

DOC-1R (deleted in oral cancer-1 related) is a novel putative tumor suppressor. This study investigated DOC-1R antitumor activity and the underlying molecular mechanisms. Cell phenotypes were assessed using flow cytometry, BrdU incorporation and CDK2 kinase assays in DOC-1R overexpressing HeLa cells. In addition, RT-PCR and Western blot assays were used to detect underlying molecular changes in these cells. The interaction between DOC-1R and CDK2 proteins was assayed by GST pull-down and immunoprecipitation-Western blot assays. The data showed that DOC-1R overexpression inhibited G1/S phase transition, DNA replication and suppressed CDK2 activity. Molecularly, DOC-1R inhibited CDK2 expression at the mRNA and protein levels, and there were decreased levels of G1-phase cyclins (cyclin D1 and E) and elevated levels of p21, p27, and p53 proteins. Meanwhile, DOC-1R associated with CDK2 and inhibited CDK2 activation by obstructing its association with cyclin E and A. In conclusion, the antitumor effects of DOC-1R may be mediated by negatively regulating G1 phase progression and G1/S transition through inhibiting CDK2 expression and activation.

Radioimmunoassay of free urinary 18-hydroxydeoxycorticosterone (18-OH-DOC) in patients with essential hypertension

International Nuclear Information System (INIS)

Hornung, J.; Gless, K.H.; Abdelhamid, S.; Vielhauer, W.; Vecsei, P.

1978-01-01

Specific antiserum was raised in white New Zealand rabbits using 18-hydroxydeoxycorticosterone-3-oxime-BSA complex as antigen. The urinary free 18-OH-DOC was estimated after dichloromethane extraction and separation in one paper chromatographic system (propylene glycol/toluene). The mean 18-OH-DOC excretion value (+-S.D.) in normal subjects was 0.861+-0.527 μg/24 h (n=23). ACTH produced a 25-fold increase in the excretion of free 18-OH-DOC. Dexamethasone suppressed the values to the lower range of sensitivity. 32% of patients of essential hypertension showed a moderate increase in the free urinary 18-OH-DOC values. The mean value (+-S.D.) in the low renin hypertension group was 2.50 +- 1.49 μg/24 h (n=19), in the normal renin patient group 1.84 +- 1.32 μg/24 h (n=38), and in the group with elevated plasma renin 1.61 +- 1.22 μg/24 h (n=8). The difference between controls and the hypertensive groups was statistically significant. Among the different hypertensive groups significant differences could not be calculated. (Auth.)

The importance of the relationship between scale and process in understanding long-term DOC dynamics.

Science.gov (United States)

Clark, J M; Bottrell, S H; Evans, C D; Monteith, D T; Bartlett, R; Rose, R; Newton, R J; Chapman, P J

2010-06-01

Concentrations of dissolved organic carbon have increased in many, but not all, surface waters across acid impacted areas of Europe and North America over the last two decades. Over the last eight years several hypotheses have been put forward to explain these increases, but none are yet accepted universally. Research in this area appears to have reached a stalemate between those favouring declining atmospheric deposition, climate change or land management as the key driver of long-term DOC trends. While it is clear that many of these factors influence DOC dynamics in soil and stream waters, their effect varies over different temporal and spatial scales. We argue that regional differences in acid deposition loading may account for the apparent discrepancies between studies. DOC has shown strong monotonic increases in areas which have experienced strong downward trends in pollutant sulphur and/or seasalt deposition. Elsewhere climatic factors, that strongly influence seasonality, have also dominated inter-annual variability, and here long-term monotonic DOC trends are often difficult to detect. Furthermore, in areas receiving similar acid loadings, different catchment characteristics could have affected the site specific sensitivity to changes in acidity and therefore the magnitude of DOC release in response to changes in sulphur deposition. We suggest that confusion over these temporal and spatial scales of investigation has contributed unnecessarily to the disagreement over the main regional driver(s) of DOC trends, and that the data behind the majority of these studies is more compatible than is often conveyed. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Metabolic patterns of 14C incorporation by selected vascular plants following field incubations with acetate-2-14C in two plant successional stages in Glacier Bay, Alaska

International Nuclear Information System (INIS)

Wu, Pei-Hsing Lin

1975-01-01

Metabolic patterns of some vascular plants (Dryas sp., Vaccinium sp., Salix sp., Alnus sp., Epilobium sp.), occurring in successional habitats, following acetate-2- 14 C incubations in the field were demonstrated for the first time. Relative radioactivity within the alcoholic soluble fraction of each species reflects its distribution in successional communities. A high level of 14 C-sugars was present in the plants of the pioneer community; on the other hand a high level of 14 C-organic acids was present in the plants of the forest community. Three patterns, based on the relative activities of the sugar- and organic acid-pools were noted which correspond to the range and the frequency of occurrence of each species in the successional stages. Only two types of 14 C-amino acid levels were noted corresponding to the range of distribution. Plants having less than 10% relative radioactivity in amino acid-pools had a limited range of distribution and reside in only one habitat; plants having more than 10% radioactivity showed wider ranges of distribution occurring in at least two habitats. (auth.)

Application of the Red List Index for conservation assessment of Spanish vascular plants.

Science.gov (United States)

Saiz, Juan Carlos Moreno; Lozano, Felipe Domínguez; Gómez, Manuel Marrero; Baudet, Ángel Bañares

2015-06-01

The International Union for Conservation of Nature (IUCN) Red List Index (RLI) is used to measure trends in extinction risk of species over time. The development of 2 red lists for Spanish vascular flora during the past decade allowed us to apply the IUCN RLI to vascular plants in an area belonging to a global biodiversity hotspot. We used the Spanish Red Lists from 2000 and 2010 to assess changes in level of threat at a national scale and at the subnational scales of Canary Islands, Balearic Islands, and peninsular Spain. We assigned retrospective IUCN categories of threat to 98 species included in the Spanish Red List of 2010 but absent in the Spanish Red List of 2000. In addition, we tested the effect of different random and taxonomic and spatial Spanish samples on the overall RLI value. From 2000 to 2010, the IUCN categories of 768 species changed (10% of Spanish flora), mainly due to improved knowledge (63%), modifications in IUCN criteria (14%), and changes in threat status (12%). All measured national and subnational RLI values decreased during this period, indicating a general decline in the conservation status of the Spanish vascular flora. The Canarian RLI value (0.84) was the lowest, although the fastest deterioration in conservation status occurred on peninsular Spain (from 0.93 in 2000 to 0.92 in 2010). The RLI values based on subsamples of the Spanish Red List were not representative of RLI values for the entire country, which would discourage the use of small areas or small taxonomic samples to assess general trends in the endangerment of national biotas. The role of the RLI in monitoring of changes in biodiversity at the global and regional scales needs further reassessment because additional areas and taxa are necessary to determine whether the index is sufficiently sensitive for use in assessing temporal changes in species' risk of extinction. © 2015 Society for Conservation Biology.

Shedding light on DOC release by benthic primary producers and its consumption by bioeroding sponges

NARCIS (Netherlands)

Müller, Benjamin

2015-01-01

The effect of light on dissolved organic carbon (DOC) release of benthic primary producers (BPPs) was investigated on the coral reefs of Curaçao. Incubation experiments revealed a positive relation between the DOC release of four Caribbean reef algae (Cladophora sp., Dictyota menstrualis, Lobophora

Doc of prophage P1 is inhibited by its antitoxin partner Phd through fold complementation

DEFF Research Database (Denmark)

Garcia-Pino, Abel; Christensen-Dalsgaard, Mikkel; Wyns, Lode

2008-01-01

Prokaryotic toxin-antitoxin modules are involved in major physiological events set in motion under stress conditions. The toxin Doc (death on curing) from the phd/doc module on phage P1 hosts the C-terminal domain of its antitoxin partner Phd (prevents host death) through fold complementation....... This Phd domain is intrinsically disordered in solution and folds into an alpha-helix upon binding to Doc. The details of the interactions reveal the molecular basis for the inhibitory action of the antitoxin. The complex resembles the Fic (filamentation induced by cAMP) proteins and suggests a possible......-antitoxin locus for its action in vivo....

Non-linear, connectivity and threshold-dominated runoff-generation controls DOC and heavy metal export in a small peat catchment

Science.gov (United States)

Birkel, Christian; Broder, Tanja; Biester, Harald

2017-04-01

Peat soils act as important carbon sinks, but they also release large amounts of dissolved organic carbon (DOC) to the aquatic system. The DOC export is strongly tied to the export of soluble heavy metals. The accumulation of potentially toxic substances due to anthropogenic activities, and their natural export from peat soils to the aquatic system is an important health and environmental issue. However, limited knowledge exists as to how much of these substances are mobilized, how they are mobilized in terms of flow pathways and under which hydrometeorological conditions. In this study, we report from a combined experimental and modelling effort to provide greater process understanding from a small, lead (Pb) and arsenic (As) contaminated upland peat catchment in northwestern Germany. We developed a minimally parameterized, but process-based, coupled hydrology-biogeochemistry model applied to simulate detailed hydrometric and biogeochemical data. The model was based on an initial data mining analysis, in combination with regression relationships of discharge, DOC and element export. We assessed the internal model DOC-processing based on stream-DOC hysteresis patterns and 3-hourly time step groundwater level and soil DOC data (not used for calibration as an independent model test) for two consecutive summer periods in 2013 and 2014. We found that Pb and As mobilization can be efficiently predicted from DOC transport alone, but Pb showed a significant non-linear relationship with DOC, while As was linearly related to DOC. The relatively parsimonious model (nine calibrated parameters in total) showed the importance of non-linear and rapid near-surface runoff-generation mechanisms that caused around 60% of simulated DOC load. The total load was high even though these pathways were only activated during storm events on average 30% of the monitoring time - as also shown by the experimental data. Overall, the drier period 2013 resulted in increased nonlinearity, but

panMetaDocs, eSciDoc, and DOIDB - an infrastructure for the curation and publication of file-based datasets for 'GFZ Data Services'

Science.gov (United States)

Ulbricht, Damian; Elger, Kirsten; Bertelmann, Roland; Klump, Jens

2016-04-01

With the foundation of DataCite in 2009 and the technical infrastructure installed in the last six years it has become very easy to create citable dataset DOIs. Nowadays, dataset DOIs are increasingly accepted and required by journals in reference lists of manuscripts. In addition, DataCite provides usage statistics [1] of assigned DOIs and offers a public search API to make research data count. By linking related information to the data, they become more useful for future generations of scientists. For this purpose, several identifier systems, as ISBN for books, ISSN for journals, DOI for articles or related data, Orcid for authors, and IGSN for physical samples can be attached to DOIs using the DataCite metadata schema [2]. While these are good preconditions to publish data, free and open solutions that help with the curation of data, the publication of research data, and the assignment of DOIs in one software seem to be rare. At GFZ Potsdam we built a modular software stack that is made of several free and open software solutions and we established 'GFZ Data Services'. 'GFZ Data Services' provides storage, a metadata editor for publication and a facility to moderate minted DOIs. All software solutions are connected through web APIs, which makes it possible to reuse and integrate established software. Core component of 'GFZ Data Services' is an eSciDoc [3] middleware that is used as central storage, and has been designed along the OAIS reference model for digital preservation. Thus, data are stored in self-contained packages that are made of binary file-based data and XML-based metadata. The eSciDoc infrastructure provides access control to data and it is able to handle half-open datasets, which is useful in embargo situations when a subset of the research data are released after an adequate period. The data exchange platform panMetaDocs [4] makes use of eSciDoc's REST API to upload file-based data into eSciDoc and uses a metadata editor [5] to annotate the files

Careers and Networking: Professional Development for Graduate Students and Post-docs

Science.gov (United States)

Jungbluth, S.; Boiteau, R.; Bottjer, D.; De Leo, F. C.; Hawko, N.; Ilikchyan, I.; Bruno, B. C.

2013-12-01

Established in 2006 by the National Science Foundation, the Center for Microbial Oceanography: Research and Education (C-MORE) is a multi-institutional Science and Technology Center based at the University of Hawai i. One of C-MORE's missions is to provide graduate students and post-docs with state-of-the-art training, which primarily occurs through laboratory- and field-based research. Additionally, C-MORE offers a Professional Development Training Program (PDTP) to help students and post-docs develop a range of "soft" skills such as science communication, leadership, proposal writing, teaching and mentoring (Bruno et al, 2013). The PDTP not only provides professional development training to graduate students and post-docs, but also encourages these young scientists to take leadership of their training. The Professional Development Organizing Committee (PDOC), composed of students and post-docs across the various C-MORE institutions, works closely with the Education Office to implement the eight core PDTP modules as well as 'on-demand' workshops. In February 2013, we organized a workshop to promote networking and foster scientific collaborations among C-MORE graduate students and post-doctoral researchers at the seven partner institutions: the University of Hawaii, Massachusetts Institute of Technology, Woods Hole Oceanographic Institution, Oregon State University, University of California Santa Cruz, Monterey Bay Aquarium Research Institute and Columbia University. The workshop was held in New Orleans in conjunction with the 2013 ASLO/ Ocean Sciences national meeting. In this paper, we will describe the student-led planning process, the workshop itself, and evaluation results. We will also present examples of some of the collaborations that resulted from this workshop.

A role of TDIF peptide signaling in vascular cell differentiation is conserved among euphyllophytes

Directory of Open Access Journals (Sweden)

Yuki eHirakawa

2015-11-01

Full Text Available Peptide signals mediate a variety of cell-to-cell communication crucial for plant growth and development. During Arabidopsis thaliana vascular development, a CLE (CLAVATA3/EMBRYO SURROUNDING REGION-related family peptide hormone, TDIF (tracheary element differentiation inhibitory factor, regulates procambial cell fate by its inhibitory activity on xylem differentiation. To address if this activity is conserved among vascular plants, we performed comparative analyses of TDIF signaling in non-flowering vascular plants (gymnosperms, monilophytes and lycophytes. We identified orthologs of TDIF/CLE as well as its receptor TDR/PXY (TDIF RECEPTOR/PHLOEM INTERCALATED WITH XYLEM in Ginkgo biloba, Adiantum aethiopicum and Selaginella kraussiana by RACE-PCR. The predicted TDIF peptide sequences in seed plants and monilophytes were identical to that of A. thaliana TDIF. We examined the effects of exogenous CLE peptide-motif sequences of TDIF in these species. We found that liquid culturing of dissected leaves or shoots was useful for examining TDIF activity during vascular development. TDIF treatment suppressed xylem/tracheary element differentiation of procambial cells in G. bioloba and A. aethiopicum leaves. In contrast, neither TDIF nor putative endogenous TDIF inhibited xylem differentiation in developing shoots and rhizophores of S. kraussiana. These data suggest that activity of TDIF in vascular development is conserved among extant euphyllophytes. In addition to the conserved function, via liquid culturing of its bulbils, we found a novel inhibitory activity on root growth in the monilophyte Asplenium x lucrosum suggesting lineage-specific co-option of peptide signaling occurred during the evolution of vascular plant organs.

Doc2B acts as a calcium sensor for vesicle priming requiring synaptotagmin-1, Munc13-2 and SNAREs

DEFF Research Database (Denmark)

Houy, Sébastien; Groffen, Alexander J; Ziomkiewicz, Iwona

2017-01-01

Doc2B is a cytosolic protein with binding sites for Munc13 and Tctex-1 (dynein light chain), and two C2-domains that bind to phospholipids, Ca2+ and SNAREs. Whether Doc2B functions as a calcium sensor akin to synaptotagmins, or in other calcium-independent or calcium-dependent capacities is debated....... We here show by mutation and overexpression that Doc2B plays distinct roles in two sequential priming steps in mouse adrenal chromaffin cells. Mutating Ca2+-coordinating aspartates in the C2A-domain localizes Doc2B permanently at the plasma membrane, and renders an upstream priming step Ca2......+-independent, whereas a separate function in downstream priming depends on SNARE-binding, Ca2+-binding to the C2B-domain of Doc2B, interaction with ubMunc13-2 and the presence of synaptotagmin-1. Another function of Doc2B - inhibition of release during sustained calcium elevations - depends on an overlapping...

Potential Responses of Vascular Plants from the Pristine "Lost World" of the Neotropical Guayana Highlands to Global Warming: Review and New Perspectives.

Science.gov (United States)

Rull, Valentí; Vegas-Vilarrúbia, Teresa

2017-01-01

The neotropical Guayana Highlands (GH) are one of the few remaining pristine environments on Earth, and they host amazing biodiversity with a high degree endemism, especially among vascular plants. Despite the lack of direct human disturbance, GH plants and their communities are threatened with extinction from habitat loss due to global warming (GW). Geographic information systems simulations involving the entire known vascular GH flora (>2430 species) predict potential GW-driven extinctions on the order of 80% by the end of this century, including nearly half of the endemic species. These estimates and the assessment of an environmental impact value for each species led to the hierarchization of plants by their risk of habitat loss and the definition of priority conservation categories. However, the predictions assume that all species will respond to GW by migrating upward and at equal rates, which is unlikely, so current estimates should be considered preliminary and incomplete (although they represent the best that can be done with the existing information). Other potential environmental forcings (i.e., precipitation shifts, an increase in the atmospheric CO 2 concentration) and idiosyncratic plant responses (i.e., resistance, phenotypic acclimation, rapid evolution) should also be considered, so detailed eco-physiological studies of the more threatened species are urgently needed. The main obstacles to developing such studies are the remoteness and inaccessibility of the GH and, especially, the difficulty in obtaining official permits for fieldwork.

Dissolved organic carbon (DOC) and coliform bacteria in ...

African Journals Online (AJOL)

Out of the 40 sites sampled during both the wet and dry seasons, 11 contained colifrorm bacteria during the wet season, while only 2 contained the microbes during the dry season. The microbes were detected only in the wells. DOC was detected in 37 sites during the wet season and in 31 sites during the dry season within ...

Absorption features of chromophoric dissolved organic matter (CDOM) and tracing implication for dissolved organic carbon (DOC) in Changjiang Estuary, China

OpenAIRE

Zhang, X. Y.; Chen, X.; Deng, H.; Du, Y.; Jin, H. Y.

2013-01-01

Chromophoric dissolved organic matter (CDOM) represents the light absorbing fraction of dissolved organic carbon (DOC). Studies have shown that the optical properties of CDOM can be used to infer the distribution and diffusion characteristics of DOC in the estuary and coastal zone. The inversion of DOC concentrations from remote sensing has been implemented in certain regions. In this study we investigate the potential of tracing DOC from CDOM by the measure...

Regionalizando a produção de documentários – DocTV

Directory of Open Access Journals (Sweden)

Karla Holanda

2013-12-01

Full Text Available DocTV Program was a project created and carried out by Brazilian Ministry of Culture (2003-2010. Documentaries on DocTV were produced in each state and exhibited on the national network by way of public stations. This regional character in their production and exhibition is rare in the history of relationship between television and independent production in Brazil. This paper details the Program’s operation as well as its guiding principles and results.

Development and psychometric properties of the Shared Decision Making Questionnaire--physician version (SDM-Q-Doc).

Science.gov (United States)

Scholl, Isabelle; Kriston, Levente; Dirmaier, Jörg; Buchholz, Angela; Härter, Martin

2012-08-01

To develop and psychometrically test a brief instrument for assessing the physician's perspective of the shared decision-making process in clinical encounters. We adapted the 9-item Shared Decision Making Questionnaire (SDM-Q-9) for patients to generate a new version for physicians (SDM-Q-Doc). The physician version was tested in clinical encounters between 29 physicians and 324 patients in German outpatient care contexts. Analyses of the extent to which the instrument was accepted, the reliability of the instrument, and the factorial structure of the scale were performed. Physicians showed a high level of acceptance toward the SDM-Q-Doc. Item discrimination parameters were above .4 for all but one item. An analysis of internal consistency yielded a Cronbach's α of .88. Factor analysis confirmed a one-dimensional structure. The results of this study suggest that the SDM-Q-Doc is a well-accepted and reliable instrument for assessing the physician's perspective during SDM processes in clinical encounters. To our knowledge, the SDM-Q-Doc is the first psychometrically tested scale available for assessing the physician's perspective. The SDM-Q-Doc can be used in studies that analyze the effectiveness of the implementation of SDM and as a quality indicator in quality assurance programs and health service assessments. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Temporal-spatial variation of DOC concentration, UV absorbance and the flux estimation in the Lower Dagu River, China

Science.gov (United States)

Xi, Min; Kong, Fanlong; Li, Yue; Kong, Fanting

2017-12-01

Dissolved organic carbon (DOC) is an important component for both carbon cycle and energy balance. The concentration, UV absorbance, and export flux of DOC in the natural environment dominate many important transport processes. To better understand the temporal and spatial variation of DOC, 7 sites along the Lower Dagu River were chosen to conduct a comprehensive measurement from March 2013 to February 2014. Specifically, water samples were collected from the Lower Dagu River between the 26th and 29th of every month during the experimental period. The DOC concentration (CDOC) and UV absorbance were analyzed using a total organic carbon analyzer and the ultraviolet-visible absorption spectrum, and the DOC export flux was estimated with a simple empirical model. The results showed that the CDOC of the Lower Dagu River varied from 1.32 to 12.56 mg/L, consistent with global rivers. The CDOC and UV absorbance showed significant spatial variation in the Dagu River during the experiential period because of the upstream natural processes and human activities in the watershed. The spatial variation is mainly due to dam or reservoir constructions, riverside ecological environment changes, and non-point source or wastewater discharge. The seasonal variation of CDOC was mainly related to the source of water DOC, river runoff, and temperature, and the UV absorbance and humification degree of DOC had no obvious differences among months ( P<0.05). UV absorbance was applied to test the CDOC in Lower Dagu River using wave lengths of 254 and 280 nm. The results revealed that the annual DOC export flux varied from 1.6 to 3.76 × 105 g C/km2/yr in a complete hydrological year, significantly lower than the global average. It is worth mentioning that the DOC export flux was mainly concentrated in summer (˜90% of all-year flux in July and August), since the runoff in the Dagu River took place frequently in summer. These observations implied environment change could bring the temporal

Vascular Plant and Vertebrate Inventory of Saguaro National Park, Tucson Mountain District

Science.gov (United States)

Powell, Brian F.; Halvorson, William L.; Schmidt, Cecilia A.

2007-01-01

This report summarizes the results of the first comprehensive inventory of plants and vertebrates at the Tucson Mountain District (TMD) of Saguaro National Park, Arizona. From 2001 to 2003 we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at the district to document the presence of species within its boundaries. Park staff also carried out extensive infrared-triggered camera work for medium and large mammals from 2002-2005 and results from that effort are reported here. Our spatial sampling design for all taxa employed a combination of random and nonrandom survey sites. Survey effort was greatest for medium and large mammals and herpetofauna. Because we used repeatable study designs and standardized field methods, these inventories can serve as the first step in a biological monitoring program for the district. We also provide an overview of previous survey efforts in the district. We use data from our inventory and other surveys to compile species lists and to assess inventory completeness. The survey effort for herpetofauna, birds, and medium and large mammals was the most comprehensive ever undertaken in the district. We recorded a total of 320 plant and vertebrate species, including 21 species not previously found in the district (Table 1). Based on a review of our inventory and past research at the district, there have been a total of 723 species of plants and vertebrates found there. We believe inventories for most taxonomic groups are nearly complete. Based on our surveys, we believe the native plant and vertebrate community compositions of the district are relatively intact, though some species loss has occurred and threats are increasing, particularly to herpetofauna and larger mammals. Of particular note is the relatively small number of non-native species and their low abundance in the district, which is in contrast to many nearby natural areas. Rapidly expanding development on the west, north, and east sides of

Mosses in Ohio wetlands respond to indices of disturbance and vascular plant integrity

Science.gov (United States)

Stapanian, Martin A.; Schumacher, William; Gara, Brian; Viau, Nick

2016-01-01

We examined the relationships between an index of wetland habitat quality and disturbance (ORAM score) and an index of vascular plant integrity (VIBI-FQ score) with moss species richness and a moss quality assessment index (MQAI) in 45 wetlands in three vegetation types in Ohio, USA. Species richness of mosses and MQAI were positively associated with ORAM and VIBI-FQ scores. VIBI-FQ score was a better predictor of both moss species richness and MQAI than was either ORAM score or vegetation type. This result was consistent with the strict microhabitat requirements for many moss species, which may be better assessed by VIBI-FQ than ORAM. Probability curves as a function of VIBI-FQ score were then generated for presence of groups of moss species having the same degree of fidelity to substrate and plant communities relative to other species in the moss flora (coefficients of conservatism, CCs). Species having an intermediate- or high degree of fidelity to substrate and plant communities (i.e., species with CC ≥ 5) had a 50% probability of presence (P50) and 90% probability of presence (P90) in wetlands with intermediate- and high VIBI-FQ scores, respectively. Although moss species richness, probability of presence of species based on CC, and MQAI may reflect wetland habitat quality, the 95% confidence intervals around P50 and P90 values may be too wide for regulatory use. Moss species richness, MQAI, and presence of groups of mosses may be more useful for evaluating moss habitat quality in wetlands than a set of “indicator species.”

78 FR 68020 - Evaluation of Established Plant Pests for Action at Ports of Entry

Science.gov (United States)

2013-11-13

.... Kevin Shea, Administrator, Animal and Plant Health Inspection Service. [FR Doc. 2013-27132 Filed 11-12... DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service [Docket No. APHIS-2013-0048] Evaluation of Established Plant Pests for Action at Ports of Entry AGENCY: Animal and Plant Health Inspection...

Northward invading non-native vascular plant species in and adjacent to Wood Buffalo National Park

Energy Technology Data Exchange (ETDEWEB)

Wein, R.W.; Wein, G.; Bahret, S.; Cody, W.J. (Alberta University, Edmonton, AB (Canada). Canadian Circumpolar Institute)

A survey of the non-native vascular plant species in Wood Buffalo National Park, Canada's largest forested National Park, documented their presence and abundance in key locations. Most of the fifty-four species (nine new records) were found in disturbed sites including roadsides, settlements, farms, areas of altered hydrological regimes, recent bums, and intensive bison grazing. Species that have increased most in geographic area and abundance in recent years include [ital Agropyron repens], [ital Bromus inermis], [ital Chenopodium album], [ital Melilotus spp.], [ital Trifolium spp.], [ital Plantago major], [ital Achillea millefolium], [ital Crepis tectorum] and [ital Sonchus arvensis]. An additional 20 species, now common in the Peace River and Fort Vermilion areas, have the potential to invade the Park if plant communities are subjected to additional stress as northern climates are modified by the greenhouse effect and as other human-caused activities disturb the vegetation. It is recommended that permanent plots be located in key locations and monitored for species invasion and changing abundances as input to management plans.

Fido, a novel AMPylation domain common to fic, doc, and AvrB.

Directory of Open Access Journals (Sweden)

Lisa N Kinch

2009-06-01

Full Text Available The Vibrio parahaemolyticus type III secreted effector VopS contains a fic domain that covalently modifies Rho GTPase threonine with AMP to inhibit downstream signaling events in host cells. The VopS fic domain includes a conserved sequence motif (HPFx[D/E]GN[G/K]R that contributes to AMPylation. Fic domains are found in a variety of species, including bacteria, a few archaea, and metazoan eukaryotes.We show that the AMPylation activity extends to a eukaryotic fic domain in Drosophila melanogaster CG9523, and use sequence and structure based computational methods to identify related domains in doc toxins and the type III effector AvrB. The conserved sequence motif that contributes to AMPylation unites fic with doc. Although AvrB lacks this motif, its structure reveals a similar topology to the fic and doc folds. AvrB binds to a peptide fragment of its host virulence target in a similar manner as fic binds peptide substrate. AvrB also orients a phosphate group from a bound ADP ligand near the peptide-binding site and in a similar position as a bound fic phosphate.The demonstrated eukaryotic fic domain AMPylation activity suggests that the VopS effector has exploited a novel host posttranslational modification. Fic domain-related structures give insight to the AMPylation active site and to the VopS fic domain interaction with its host GTPase target. These results suggest that fic, doc, and AvrB stem from a common ancestor that has evolved to AMPylate protein substrates.

Origin and Evolution of The Early- Silurian Land Vascular Plants: Evidence From Biomarkers

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Jin, R.

2016-12-01

Origin and early evolution of land vascular plants, is one of the most intriguing hotspots in the life science research. During the 1970s and 1980s,Pinnatiramosus qianensis was found in early-Silurian strata in guizhou of south China.43 years have passed. But so far, the biological characteristics and belonging of the age of this unique plant have been debated again and again, up in the air.Biomarkers have a good stability in the process of organic evolution, no more or less changed, so they have a special `function of mark'. While biomarkers can provide information about organic matter of hydrocarbon source rock (the source), the period of deposition and burial (diagenesis) environmental conditions, and many other aspects of information.This paper obtained the sedimentary environment, source of organic matter input and other relevant information, through extracting and analyzing biomarkers of the 26 samples in the late Ordovician to early Silurian strata in NorthGuizhou areas. According to the results, Pr/Ph of late Ordovician Meitan Fm-early Silurian Hanjiadian Fm is high.It manifests more pristane, characterized by reductive environment. At the bottom of the Hanjiadian Fm, Pr/Ph has a volatility.Some huge environmental changes may have taken place in the corresponding period. N-alkanes do not have parity advantage or has even carbon advantage slightly.The peak carbon is mainly in low carbon number.(C21 + C22)/(C28 + C29) is high.Aquatic organisms is a major source of organic matter during this period,C21-/C22+ is low.This may be caused by the relatively serious loss of light hydrocarbon during the separation of components. In the Hanjiadian Fm,information of C29/C27 sterane ratios and oleanane index showed a trend of rising at the same time, indicating that during this period, there was a gradual increase input in the number of higher plants.The stable carbon isotope of saturated hydrocarbon and aromatic hydrocarbon in the Hanjiadian Fm also gradually become

Distinct expression of alkaline phosphatase activity in epilimnetic bacteria: Implication for persistent DOC consumption in a P-limited reservoir

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Tseng, Y.; Kao, S.; Shiah, F.

2013-12-01

In a P-deficient system, P availability usually controls the microbial activity and thus the ecosystem function. Thingstad et al. (1997) first addressed a 'Malfunctioning Microbial-loop' theory, which stated that low bacterial production (BP) caused by insufficient nutrient supply would result in DOC accumulation in an oligotrophic ecosystem. In this study we re-examined the theory by conducting seasonal patterns and correlations among soluble reactive phosphate (SRP) and DOC, microbial abundances (picocyanobacteria, bacteria, and heterotrophic nanoflagellate; HNF) and activities (primary production, bacterial production, and alkaline phosphatase activity; APA) coupled with enzyme-labeled fluorescence (ELF) assays on bacterioplankton in a subtropical reservoir sharing the common features, nitrate-replete and P-deficient, with most natural freshwater system during Oct 2007-Oct 2008. Persistently high APA was recorded during most of time, implying that the system was P-deficient. Size fractionated APA and ELF assay revealed that bacteria were the major APA contributor. However, significantly low epilimnion DOC was recorded during the stratified summer season accompanying with high BP and APA as well as high PP, implying that heterotrophic bacteria can well sustain in P-deficient system by utilizing DOP to rapidly lower down DOC under relatively high PP. Such findings oppose the 'Malfunctioning Microbial-loop' theory. On the other hand, strong epilimnetic DOC accumulation occurred in Oct 2007 under low light and low PP condition accompanying with high abundance of HNF, implying that HNF grazing may contribute to a certain degree of DOC accumulation. Correlation matrix supported our suggestions. This study testified the DOC dynamics in P-deficient ecosystem are tightly coupled with the source (PP and grazing) and sink (BP). We also suggested that in SRP-limited freshwater systems bacteria are capable of breaking down autochthonous DOC to reduce the chance of DOC

Photosynthetic limitations in two Antarctic vascular plants: importance of leaf anatomical traits and Rubisco kinetic parameters.

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Sáez, Patricia L; Bravo, León A; Cavieres, Lohengrin A; Vallejos, Valentina; Sanhueza, Carolina; Font-Carrascosa, Marcel; Gil-Pelegrín, Eustaquio; Javier Peguero-Pina, José; Galmés, Jeroni

2017-05-17

Particular physiological traits allow the vascular plants Deschampsia antarctica Desv. and Colobanthus quitensis (Kunth) Bartl. to inhabit Antarctica. The photosynthetic performance of these species was evaluated in situ, focusing on diffusive and biochemical constraints to CO2 assimilation. Leaf gas exchange, Chl a fluorescence, leaf ultrastructure, and Rubisco catalytic properties were examined in plants growing on King George and Lagotellerie islands. In spite of the species- and population-specific effects of the measurement temperature on the main photosynthetic parameters, CO2 assimilation was highly limited by CO2 diffusion. In particular, the mesophyll conductance (gm)-estimated from both gas exchange and leaf chlorophyll fluorescence and modeled from leaf anatomy-was remarkably low, restricting CO2 diffusion and imposing the strongest constraint to CO2 acquisition. Rubisco presented a high specificity for CO2 as determined in vitro, suggesting a tight co-ordination between CO2 diffusion and leaf biochemistry that may be critical ultimately to optimize carbon balance in these species. Interestingly, both anatomical and biochemical traits resembled those described in plants from arid environments, providing a new insight into plant functional acclimation to extreme conditions. Understanding what actually limits photosynthesis in these species is important to anticipate their responses to the ongoing and predicted rapid warming in the Antarctic Peninsula. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Northern peatland carbon biogeochemistry. The influence of vascular plants and edaphic factors on carbon dioxide and methane exchange

International Nuclear Information System (INIS)

Oequist, M.

2001-01-01

The findings reported in this thesis and in the accompanying papers are based on both laboratory and field investigations of carbon transformation dynamics on the process scale and at the resolution of individual peatland plant communities. The data from one of the studies also is extrapolated in an attempt to identify environmental controls on regional scales in order to predict the response of northern peatlands to climate warming. The laboratory experiments focus on how climate variations, inducing fluctuations in groundwater level and also soil freeze-thaw cycles, influences organic matter mineralisation to carbon dioxide and methane. The field studies investigate year-to-year variations and interdecadal differences in carbon gas exchange at a subarctic peatland, and also how the physiological activities of vascular plants control methane emission rates. The main conclusions presented include: Soil freeze-thaw events may be very important for the annual carbon balance in northern peatlands, because they have the potential to increase mineralisation rates and alter biogeochemical degradation pathways. Vascular plants exert a strong influence on methane flux dynamics during the growing season, both by mediating methane transport and through substrate-based interactions with the soil microbial community. However, there are important species-related factors that govern the nature and extent of this influence. Caution has to be taken when extrapolating field data to estimate regional carbon exchange because the relevance of the specific environmental parameters that control this exchange varies depending on resolution. On broad spatial and temporal scales the best predictor of peatland methane emissions is mean soil temperature, but also microbial substrate availability (expressed as the organic acid concentration in peat water) is of importance. This temperature sensitivity represents a strong potential feedback mechanism on climate change

Validation of SDM-Q-Doc Questionnaire to measure shared decision-making physician's perspective in oncology practice.

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Calderon, C; Ferrando, P J; Carmona-Bayonas, A; Lorenzo-Seva, U; Jara, C; Beato, C; García, T; Ramchandani, A; Castelo, B; Muñoz, M M; Garcia, S; Higuera, O; Mangas-Izquierdo, M; Jimenez-Fonseca, P

2017-11-01

The aim of this study was to analyze the psychometric properties of the Shared Decision-Making Questionnaire-Physician version (SDM-Q-Doc) in a sample of medical oncologists who provide adjuvant treatment to patients with non-metastatic resected cancer and the correlations between the total SDM-Q-Doc score and physician satisfaction with the information provided. Prospective, observational and multicenter study in which 32 medical oncologists and 520 patients were recruited. The psychometric properties, dimensionality, and factor structure of the SDM-Q-Doc were assessed. Exploratory factor analyses suggested that the most likely solution was two-dimensional, with two correlated factors: one factor regarding information and another one about treatment. Confirmatory factor analysis based on cross-validation showed that the fitted two-dimensional solution provided the best fit to the data. Reliability analyses revealed good accuracy for the derived scores, both total and sub-scale, with estimates ranging from 0.81 to 0.89. The results revealed significant correlations between the total SDM-Q-Doc score and physician satisfaction with the information provided (p Doc showed good psychometric properties and could be a helpful tool that examines physician's perspective of SDM and as an indicator of quality and satisfaction in patients with cancer.

Cross-regional prediction of long-term trajectory of stream water DOC response to climate change

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H. Laudon; J.M. Buttle; S.K. Carey; J.J. McDonnell; K.J. McGuire; J. Seibert; J. Shanley; C. Soulsby; D. Tetzlaff

2012-01-01

There is no scientific consensus about how dissolved organic carbon (DOC) in surface waters is regulated. Here we combine recent literature data from 49 catchments with detailed stream and catchment process information from nine well established research catchments at mid- to high latitudes to examine the question of how climate controls stream water DOC. We show for...

Resuspension of polychlorinated biphenyl-contaminated field sediment: release to the water column and determination of site-specific K DOC.

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Friedman, Carey L; Lohmann, Rainer; Burgess, Robert M; Perron, Monique M; Cantwell, Mark G

2011-02-01

Sediments from the New Bedford Harbor (NBH) U.S. Environmental Protection Agency (U.S. EPA) Superfund site (Massachusetts, USA), contaminated with polychlorinated biphenyls (PCBs), were resuspended under different water column redox conditions: untreated, oxidative, and reductive. The partitioning of PCBs to the overlying water column was measured with polyethylene samplers and compared to partitioning without resuspension. Greater concentrations of total aqueous (freely dissolved + dissolved organic carbon (DOC)-associated) PCBs were found in all resuspended treatments for PCBs with mid-range K(OW)s, but no difference was observed in total aqueous concentrations among different redox conditions. The magnitude of increased concentrations depended on resuspension time and congener K(OW), but ranged from approximately one to eight times those found without resuspension. In a parallel study, DOC was flocculated and removed from smaller-scale NBH sediment resuspensions. In situ K(DOC)s were determined and used to calculate freely dissolved and DOC-associated fractions of the increase in total aqueous PCB concentrations due to resuspension. The importance of DOC-associated PCBs increased with increasing K(OW). In situ K(DOC)s were approximately one to two orders of magnitude greater than those calculated with a commonly used linear free energy relationship (LFER). The present study demonstrates that resuspension of contaminated sediments releases PCBs to the water column, of which a significant fraction are DOC-associated (e.g., 28, 65, and 90% for PCBs 28, 66, and 110, respectively). Results also imply that site-specific PCB K(DOC)s are superior to those calculated with generic LFERs. © 2010 SETAC.

Control of Vascular Streak Dieback Disease of Cocoa with Flutriafol Fungicides

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Febrilia Nur'aini

2014-12-01

Full Text Available Vascular streak dieback caused by the fungus Oncobasidium theobromae is one of the important diseases in cocoa crop in Indonesia. One approach to control the disease is by using fungicides. The aim of this research was to determine the effect of class triazole fungicides to the intensity of the vascular streak dieback disease on cocoa seedling phase, immature and mature cocoa. Experiments were conducted in Kotta Blater, PTPN XII and Kaliwining, Indonesian  Coffee and Cocoa Research Institute. Flutriafol 250 g/l with a concentration 0,05%, 0,1% and 0,15% foliar sprayed on cocoa seedlings, immature and mature cocoa. Active compound combination of Azoxystrobin and Difenoconazole with 0,1% concentration used as a comparation fungicides. The result showed that Flutriafol with 0,05%, 0,1% and 0,15% concentration and Azoxystrobin & Difenoconazol with 0,1% concentration could suppress the vascular streak dieback disease on seedlings. On immature plants, the application of Flutriafol was not effectively suppress the vascular streak dieback disease whereas the fungicide comparison could suppress with the efficacy level of 46.22%. On mature plants,both of fungicides could not suppress the vascular streak dieback disease. Key words: Fungicide, cocoa, vascular streak dieback, triazole, flutriafol, azoxystrobin+difenoconazol

Long-term environmental drivers of DOC fluxes: Linkages between management, hydrology and climate in a subtropical coastal estuary

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Regier, Peter; Briceño, Henry; Jaffé, Rudolf

2016-12-01

Urban and agricultural development of the South Florida peninsula has disrupted historic freshwater flow in the Everglades, a hydrologically connected ecosystem stretching from central Florida to the Gulf of Mexico, USA. Current system-scale restoration efforts aim to restore natural hydrologic regimes to reestablish pre-drainage ecosystem functioning through increased water availability, quality and timing. Aquatic transport of carbon in this ecosystem, primarily as dissolved organic carbon (DOC), plays a critical role in biogeochemical cycling and food-web dynamics, and will be affected both by water management policies and climate change. To better understand DOC dynamics in South Florida estuaries and how hydrology, climate and water management may affect them, 14 years of monthly data collected in the Shark River estuary were used to examine DOC flux dynamics in a broader environmental context. Multivariate statistical methods were applied to long-term datasets for hydrology, water quality and climate to untangle the interconnected environmental drivers that control DOC export at monthly and annual scales. DOC fluxes were determined to be primarily controlled by hydrology but also by seasonality and long-term climate patterns and episodic weather events. A four-component model (salinity, rainfall, inflow, Atlantic Multidecadal Oscillation) capable of predicting DOC fluxes (R2 = 0.84, p water management and salinity.

Potential Responses of Vascular Plants from the Pristine “Lost World” of the Neotropical Guayana Highlands to Global Warming: Review and New Perspectives

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Rull, Valentí; Vegas-Vilarrúbia, Teresa

2017-01-01

The neotropical Guayana Highlands (GH) are one of the few remaining pristine environments on Earth, and they host amazing biodiversity with a high degree endemism, especially among vascular plants. Despite the lack of direct human disturbance, GH plants and their communities are threatened with extinction from habitat loss due to global warming (GW). Geographic information systems simulations involving the entire known vascular GH flora (>2430 species) predict potential GW-driven extinctions on the order of 80% by the end of this century, including nearly half of the endemic species. These estimates and the assessment of an environmental impact value for each species led to the hierarchization of plants by their risk of habitat loss and the definition of priority conservation categories. However, the predictions assume that all species will respond to GW by migrating upward and at equal rates, which is unlikely, so current estimates should be considered preliminary and incomplete (although they represent the best that can be done with the existing information). Other potential environmental forcings (i.e., precipitation shifts, an increase in the atmospheric CO2 concentration) and idiosyncratic plant responses (i.e., resistance, phenotypic acclimation, rapid evolution) should also be considered, so detailed eco-physiological studies of the more threatened species are urgently needed. The main obstacles to developing such studies are the remoteness and inaccessibility of the GH and, especially, the difficulty in obtaining official permits for fieldwork. PMID:28179913

Vascular Plant and Vertebrate Inventory of Saguaro National Park, Rincon Mountain District

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Powell, Brian F.; Halvorson, William Lee; Schmidt, Cecilia A.

2006-01-01

Executive Summary This report summarizes the results of the first comprehensive inventory of plants and vertebrates at the Rincon Mountain District (RMD) of Saguaro National Park, Arizona. From 2001 to 2003 we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at the district to document the presence of species within its boundaries. Park staff also surveyed for medium and large mammals using infrared-triggered cameras from 1999 to 2005. This report summarizes the methods and results of these two efforts. Our spatial sampling design was ambitious and was one of the first of its kind in the region to colocate study sites for vegetation and vertebrates using a stratified random design. We also chose the location of some study sites non-randomly in areas that we thought would have the highest species richness. Because we used repeatable study designs and standardized field methods, these inventories can serve as the first step in a biological monitoring program for the district. We also provide an important overview of most previous survey efforts in the district. We use data from our inventory and other surveys to compile species lists and to assess inventory completeness. With the exception of plants, our survey effort was the most comprehensive ever undertaken in the district. We recorded a total of 801 plant and vertebrate species, including 50 species not previously found in the district (Table 1) of which five (all plants) are non-native species. Based on a review of our inventory and past research at the district, there have been a total of 1,479 species of plants and vertebrates found there. We believe inventories for all taxonomic groups are nearly complete. In particular, the plant, amphibian and reptile, and mammal species lists are the most complete of any comparably large natural area of the 'sky island' region of southern Arizona and adjacent Mexico. For each taxon-specific chapter we discuss patterns of species

Contrasting land uses in Mediterranean agro-silvo-pastoral systems generated patchy diversity patterns of vascular plants and below-ground microorganisms.

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Bagella, Simonetta; Filigheddu, Rossella; Caria, Maria Carmela; Girlanda, Mariangela; Roggero, Pier Paolo

2014-12-01

The aims of this paper were (i) to define how contrasting land uses affected plant biodiversity in Mediterranean agro-silvo-pastoral-systems across a gradient of disturbance regimes: cork oak forests, secondary grasslands, hay crops, grass covered vineyards, tilled vineyards; (ii) to determine whether these patterns mirrored those of below-ground microorganisms and whether the components of γ-diversity followed a similar model. The disturbance regimes affected plant assemblage composition. Species richness decreased with increasing land use intensity, the Shannon index showed the highest values in grasslands and hay crops. Plant assemblage composition patterns mirrored those of Basidiomycota and Ascomycota. Richness in Basidiomycota, denitrifying bacteria and microbial biomass showed the same trend as that observed for vascular plant richness. The Shannon index pattern of below-ground microorganisms was different from that of plants. The plant γ-diversity component model weakly mirrored those of Ascomycota. Patchy diversity patterns suggest that the maintenance of contrasting land uses associated with different productions typical of agro-silvo-pastoral-systems can guarantee the conservation of biodiversity. Copyright © 2014 Académie des sciences. Published by Elsevier SAS. All rights reserved.

The perception of strigolactones in vascular plants.

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Lumba, Shelley; Holbrook-Smith, Duncan; McCourt, Peter

2017-05-17

Small-molecule hormones play central roles in plant development, ranging from cellular differentiation and organ formation to developmental response instruction in changing environments. A recently discovered collection of related small molecules collectively called strigolactones are of particular interest, as these hormones also function as ecological communicators between plants and fungi and between parasitic plants and their hosts. Advances from model plant systems have begun to unravel how, as a hormone, strigolactone is perceived and transduced. In this Review, we summarize this information and examine how understanding strigolactone hormone signaling is leading to insights into parasitic plant infections. We specifically focus on how the development of chemical probes can be used in combination with model plant systems to dissect strigolactone's perception in the parasitic plant Striga hermonthica. This information is particularly relevant since Striga is considered one of the largest impediments to food security in sub-Saharan Africa.

Assessing quality and quantity of groundwater DOC in relation to plant export from different over-winter green-cover treatments in tillage farming systems

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Premrov, Alina; Coxon, Catherine; Hackett, Richard; Richards, Karl

2010-05-01

The biogeochemistry of nitrogen is often connected to carbon and C/N dynamics. The dissolved organic carbon (DOC) electron donor availability can be related to groundwater denitrification (Buss, et al. 2005). Therefore groundwater nitrate attenuation processes are also frequently linked to carbon availability. In recent years the role of over-winter green cover in tillage farming has been studied extensively. Nevertheless further research on the biogeochemical effect of green cover on soil/sediment and groundwater quality is still needed. In particular plant roots are known to exude different types of organic compounds, but their role in groundwater quality has not been investigated in depth. According to Cannavo et al. (2004a,b), in addition to quantity, the quality of water-extractable soil organic matter (e.g. molecular size/weight) has also an important role for microbial activity. In this study we investigate the effect of over-winter green-cover on potential DOC export to shallow groundwater (2 - 5 m below ground level), located on tillage land in Oak Park, Carlow, Ireland. The experiment includes three over-winter green-cover treatments: natural green-cover, mustard and no-cover (sprayed with herbicide following harvest); and is underlain by a sand and gravel aquifer. The site is equipped with 4 shallow piezometers per treatment (total no. of piezometers is 20, including treatments and surrounding piezometers). In addition to monitoring the quantity of DOC concentrations in shallow groundwater under different green cover treatments over time, an attempt was made to evaluate the quality of dissolved organic matter in shallow groundwater using Excitation Emission Fluorescence Matrix (EEFM) profiles obtained from analyses performed on a Varian Fluorescence Spectrophotometer of a single batch of samples (from all 20 installed piezometers in September 2009). To evaluate the quality of dissolved organic matter in shallow groundwater, computation of the

Dynamics of dissolved organic carbon (DOC) through stormwater basins designed for groundwater recharge in urban area: Assessment of retention efficiency.

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Mermillod-Blondin, Florian; Simon, Laurent; Maazouzi, Chafik; Foulquier, Arnaud; Delolme, Cécile; Marmonier, Pierre

2015-09-15

Managed aquifer recharge (MAR) has been developed in many countries to limit the risk of urban flooding and compensate for reduced groundwater recharge in urban areas. The environmental performances of MAR systems like infiltration basins depend on the efficiency of soil and vadose zone to retain stormwater-derived contaminants. However, these performances need to be finely evaluated for stormwater-derived dissolved organic matter (DOM) that can affect groundwater quality. Therefore, this study examined the performance of MAR systems to process DOM during its transfer from infiltration basins to an urban aquifer. DOM characteristics (fluorescent spectroscopic properties, biodegradable and refractory fractions of dissolved organic carbon -DOC-, consumption by micro-organisms during incubation in slow filtration sediment columns) were measured in stormwater during its transfer through three infiltration basins during a stormwater event. DOC concentrations sharply decreased from surface to the aquifer for the three MAR sites. This pattern was largely due to the retention of biodegradable DOC which was more than 75% for the three MAR sites, whereas the retention of refractory DOC was more variable and globally less important (from 18% to 61% depending on MAR site). Slow filtration column experiments also showed that DOC retention during stormwater infiltration through soil and vadose zone was mainly due to aerobic microbial consumption of the biodegradable fraction of DOC. In parallel, measurements of DOM characteristics from groundwaters influenced or not by MAR demonstrated that stormwater infiltration increased DOC quantity without affecting its quality (% of biodegradable DOC and relative aromatic carbon content -estimated by SUVA254-). The present study demonstrated that processes occurring in soil and vadose zone of MAR sites were enough efficient to limit DOC fluxes to the aquifer. Nevertheless, the enrichments of DOC concentrations measured in groundwater below

Vascular Plants of the Chimbote Wetlands, Peru

OpenAIRE

Arana, César; Salinas, Letty

2013-01-01

Los humedales de Chimbote (09°05’51"S; 78°32’52"O) presentan una flora vascular compuesta por 41 especies en 18 familias. El 61% magnoliópsidas y el 39% liliópsidas. Las familias con mayor número de especies fueron Poaceae, Cyperaceae y Asteraceae. Las formas de crecimiento dominantes fueron las hierbas (85%) seguidas de arbustos (10%). En comparación con los humedales costeros de Lima, en Chimbote se presenta mayor riqueza de especies que en Medio Mundo (16 especies) y El Paraíso (25), aunqu...

Master function for the solid:solution equilibrium of DOC in taiga and tundra soils of N. Russia: experimental and modeling results

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Oosterwoud, M. R.; van der Zee, S. E. A. T. M.; Meeussen, J. C. L.; Temminghoff, E. J. M.

2012-04-01

The formation and degradation of Dissolved Organic Carbon (DOC) in arctic environments is intensively investigated, in the context of DOC loading of arctic rivers and seas as well as climate change. However, chemical interaction studies are more scarce, in particular those involving modeling. We investigated DOC interactions in N. Russian taiga and tundra soils, and found that water extractable organic carbon (WEOC) comprises only a small fraction of total organic carbon, whereas DOC is again a small fraction of WEOC. The chemical composition of DOC in terms of humic, fulvic, and hydrophilic acids, the concentrations of dominant cations such as Ca and Al, and the solid iron oxide contents appear to differ profoundly for different soil horizons, as well as between taiga and tundra soils. To reconcile these differences, we processed the data with a simple Freundlich model and with advanced LCD (Ligand and Charge Distribution) modeling of DOC interactions. In the LCD modeling, a combination is made of advances such as CD-MUSIC, and Nica-Donnan approaches, that are implemented in the software ORCHESTRA (though adjusted for computational stability by us). To avoid fitting without good foundation, use is made of the generic parameterization of LCD in combination with measured, site-specific chemical data such as concentrations. We observe that the soil samples from both regions, soil types and horizons can be described with a single DOC sorption Freundlich isotherm. More interestingly, for the same set of samples, the LCD modeling enables us to cast DOC sorption into a single Master Function, that takes iron oxide content and Al and Ca concentrations of soil samples into account in a purely predictive way. Based on this Master Function, it is feasible to assess how DOC is sorbed onto the solid surface. In combination with DOC production and degradation models, our results provide a more balanced instrument to address changes in DOC loading to surface waters due to

TAS3 miR390-dependent loci in non-vascular land plants: towards a comprehensive reconstruction of the gene evolutionary history

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Sergey Y. Morozov

2018-04-01

Full Text Available Trans-acting small interfering RNAs (ta-siRNAs are transcribed from protein non-coding genomic TAS loci and belong to a plant-specific class of endogenous small RNAs. These siRNAs have been found to regulate gene expression in most taxa including seed plants, gymnosperms, ferns and mosses. In this study, bioinformatic and experimental PCR-based approaches were used as tools to analyze TAS3 and TAS6 loci in transcriptomes and genomic DNAs from representatives of evolutionary distant non-vascular plant taxa such as Bryophyta, Marchantiophyta and Anthocerotophyta. We revealed previously undiscovered TAS3 loci in plant classes Sphagnopsida and Anthocerotopsida, as well as TAS6 loci in Bryophyta classes Tetraphidiopsida, Polytrichopsida, Andreaeopsida and Takakiopsida. These data further unveil the evolutionary pathway of the miR390-dependent TAS3 loci in land plants. We also identified charophyte alga sequences coding for SUPPRESSOR OF GENE SILENCING 3 (SGS3, which is required for generation of ta-siRNAs in plants, and hypothesized that the appearance of TAS3-related sequences could take place at a very early step in evolutionary transition from charophyte algae to an earliest common ancestor of land plants.

TAS3 miR390-dependent loci in non-vascular land plants: towards a comprehensive reconstruction of the gene evolutionary history.

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Morozov, Sergey Y; Milyutina, Irina A; Erokhina, Tatiana N; Ozerova, Liudmila V; Troitsky, Alexey V; Solovyev, Andrey G

2018-01-01

Trans-acting small interfering RNAs (ta-siRNAs) are transcribed from protein non-coding genomic TAS loci and belong to a plant-specific class of endogenous small RNAs. These siRNAs have been found to regulate gene expression in most taxa including seed plants, gymnosperms, ferns and mosses. In this study, bioinformatic and experimental PCR-based approaches were used as tools to analyze TAS3 and TAS6 loci in transcriptomes and genomic DNAs from representatives of evolutionary distant non-vascular plant taxa such as Bryophyta, Marchantiophyta and Anthocerotophyta. We revealed previously undiscovered TAS3 loci in plant classes Sphagnopsida and Anthocerotopsida, as well as TAS6 loci in Bryophyta classes Tetraphidiopsida, Polytrichopsida, Andreaeopsida and Takakiopsida. These data further unveil the evolutionary pathway of the miR390-dependent TAS3 loci in land plants. We also identified charophyte alga sequences coding for SUPPRESSOR OF GENE SILENCING 3 (SGS3), which is required for generation of ta-siRNAs in plants, and hypothesized that the appearance of TAS3-related sequences could take place at a very early step in evolutionary transition from charophyte algae to an earliest common ancestor of land plants.

Solar ultraviolet photodegradation of DOC may stimulate freshwater food webs

NARCIS (Netherlands)

Lange, de H.J.; Morris, D.P.; Williamson, C.E.

2003-01-01

The UV component in solar radiation increased the availability of DOC for bacterial growth, and led to an increase in bacterial and bacterivore abundance in laboratory plankton cultures. UV radiation may thus stimulate ecosystem productivity by increasing dissolved organic carbon lability and

Florisitic summary of 'Manual of Vascular Plants of Northeastern United States and Adjacent Canada', second edition

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Bennett, J.P.

1996-01-01

The second edition of the Manual of Vascular Plants of Northeastern United States and Adjacent Canada by Gleason and Cronquist (1991) is the most recent and up-to-date taxonomic treatment of the flora of that region. Since no floristic summary of the Manual was included in the publication, a computer analysis of the taxonomic data of the Manual was performed in order to generate a floristic summary. Totals of 4285 species, 1091 genera, and 191 families were tabulated. The largest genus was Carex, with 230 species; the largest family was the Asteraceae, with 528 species. Comparisons made with earlier floras of the same region indicated small declines on the order of 10% for these taxonomic groups.

Effects of ozone as a stand-alone and coagulation-aid treatment on the reduction of trihalomethanes precursors from high DOC and hardness water.

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Sadrnourmohamadi, Mehrnaz; Gorczyca, Beata

2015-04-15

This study investigates the effect of ozone as a stand-alone and coagulation aid on the removal of dissolved organic carbon (DOC) from the water with a high level of DOC (13.8 mgL(-1)) and calcium hardness (270 mgL(-1)) CaCO3. Natural water collected from the Assiniboine River (Manitoba, Canada) was used in this study. Effectiveness of ozone treatment was evaluated by measurement of DOC, DOC fractions, UV254, and trihalomethane formation potential (THMFP). Additionally, zeta potential and dissolved calcium concentration were measured to discern the mechanism of ozone reactions. Results indicated that 0.8 mg O3/mg DOC ozone stand-alone can cause up to 86% UV254 reduction and up to 27% DOC reduction. DOC fractionation results showed that ozone can change the composition of DOC in the water samples, converting the hydrophobic fractions into hydrophilic ones and resulting in the reduction of THMFP. Also, ozone caused a decrease in particle stability and dissolved calcium concentration. These simultaneous ozonation effects caused improved water flocculation and enhanced removal of DOC. This resulted in reduction of the coagulant dosage when ozone doses higher than 0.2 mg O3/mg DOC were applied prior to coagulation with ferric sulfate. Also, pre-ozonation-coagulation process achieved preferential THMFP removal for all of the ozone doses tested (0-0.8 mg O3/mg DOC), leading to a lower specific THMFP in pre-ozonated-coagulated waters than in the corresponding ozonated waters. Copyright © 2015 Elsevier Ltd. All rights reserved.

ICF-DOC: the ICF dedicated checklist for evaluating functioning and disability in people with disorders of consciousness.

Science.gov (United States)

Leonardi, Matilde; Covelli, Venusia; Giovannetti, Ambra M; Raggi, Alberto; Sattin, Davide

2014-09-01

Clinicians need a comprehensive description of patients' functioning state to capture the complex interaction between symptoms and environmental factors, and to determine the actual level of functioning in patients in a vegetative state or a minimally conscious state. The aim of this study is to develop an International Classification of Functioning, Disability, and Health (ICF) checklist for patients with disorders of consciousness (DOC) so as to capture and describe, with a tailored list of categories, the most common health, disability, and functioning issues of adult patients with DOC. The WHO ICF checklist was used as a basis for collecting data. This was an observational, cross-sectional, multicenter study conducted in 69 Italian centers. Specific methodological procedures were used to identify the most appropriate categories for DOC patients to be added to or deleted from the ICF checklist so as to develop the ICF-DOC checklist. A total of 566 adult patients were enrolled: 398 in a vegetative state and 168 in a minimally conscious state. A total of 127 ICF categories reached the threshold of 20% concerning the presence of a problem: 37 categories from the body functions chapter, 13 from the body structures chapter, 46 from the activities and participations chapter, and 31 from the environmental factors chapter. ICF categories identified in this study can be useful guidelines for clinicians and researchers to collect data on functioning and disability of adult patients with DOC. The new ICF-DOC checklist allows monitoring of the effects of interventions on functional areas and possible changes in each patient in follow-up studies.

Adsorption and bioadsorption of granular activated carbon (GAC) for dissolved organic carbon (DOC) removal in wastewater.

Science.gov (United States)

Xing, W; Ngo, H H; Kim, S H; Guo, W S; Hagare, P

2008-12-01

In this study, the performances of GAC adsorption and GAC bioadsorption in terms of dissolved organic carbon (DOC) removal were investigated with synthetic biologically treated sewage effluent (BTSE), synthetic primary treated sewage effluent (PTSE), real BTSE and real PTSE. The main aims of this study are to verify and compare the efficiency of DOC removal by GAC (adsorption) and acclimatized GAC (bioadsorption). The results indicated that the performance of bioadsorption was significantly better than that of adsorption in all cases, showing the practical use of biological granular activated carbon (BGAC) in filtration process. The most significance was observed at a real PTSE with a GAC dose of 5g/L, having 54% and 96% of DOC removal by adsorption and bioadsorption, respectively. In addition, it was found that GAC adsorption equilibrium was successfully predicted by a hybrid Langmuir-Freundlich model whilst integrated linear driving force approximation (LDFA)+hybrid isotherm model could describe well the adsorption kinetics. Both adsorption isotherm and kinetic coefficients determined by these models will be useful to model the adsorption/bioadsorption process in DOC removal of BGAC filtration system.

Using Project-Based Learning and Google Docs to Support Diversity

Science.gov (United States)

Leh, Amy

2014-01-01

A graduate course, ETEC543 ("Technology and Learning I"), was revised to better serve increasing new student population, international students, in an academic program. Project-based learning, Google Docs, and instructional strategies fostering diversity and critical thinking were incorporated into the course redesign. Observations,…

Identification of the vascular plants of Churchill, Manitoba, using a DNA barcode library

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Kuzmina Maria L

2012-11-01

Full Text Available Abstract Background Because arctic plant communities are highly vulnerable to climate change, shifts in their composition require rapid, accurate identifications, often for specimens that lack diagnostic floral characters. The present study examines the role that DNA barcoding can play in aiding floristic evaluations in the arctic by testing the effectiveness of the core plant barcode regions (rbcL, matK and a supplemental ribosomal DNA (ITS2 marker for a well-studied flora near Churchill, Manitoba. Results This investigation examined 900 specimens representing 312 of the 354 species of vascular plants known from Churchill. Sequencing success was high for rbcL: 95% for fresh specimens and 85% for herbarium samples (mean age 20 years. ITS2 worked equally well for the fresh and herbarium material (89% and 88%. However, sequencing success was lower for matK, despite two rounds of PCR amplification, which reflected less effective primer binding and sensitivity to the DNA degradation (76% of fresh, 45% of herbaria samples. A species was considered as taxonomically resolved if its members showed at least one diagnostic difference from any other taxon in the study and formed a monophyletic clade. The highest species resolution (69% was obtained by combining information from all three genes. The joint sequence information for rbcL and matK distinguished 54% of 286 species, while rbcL and ITS2 distinguished 63% of 285 species. Discrimination of species within Salix, which constituted 8% of the flora, was particularly problematic. Despite incomplete resolution, the barcode results revealed 22 misidentified herbarium specimens, and enabled the identification of field specimens which were otherwise too immature to identify. Although seven cases of ITS2 paralogy were noted in the families Cyperaceae, Juncaceae and Juncaginaceae, this intergenic spacer played an important role in resolving congeneric plant species at Churchill. Conclusions Our results

Identification of the vascular plants of Churchill, Manitoba, using a DNA barcode library.

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Kuzmina, Maria L; Johnson, Karen L; Barron, Hannah R; Hebert, Paul Dn

2012-11-28

Because arctic plant communities are highly vulnerable to climate change, shifts in their composition require rapid, accurate identifications, often for specimens that lack diagnostic floral characters. The present study examines the role that DNA barcoding can play in aiding floristic evaluations in the arctic by testing the effectiveness of the core plant barcode regions (rbcL, matK) and a supplemental ribosomal DNA (ITS2) marker for a well-studied flora near Churchill, Manitoba. This investigation examined 900 specimens representing 312 of the 354 species of vascular plants known from Churchill. Sequencing success was high for rbcL: 95% for fresh specimens and 85% for herbarium samples (mean age 20 years). ITS2 worked equally well for the fresh and herbarium material (89% and 88%). However, sequencing success was lower for matK, despite two rounds of PCR amplification, which reflected less effective primer binding and sensitivity to the DNA degradation (76% of fresh, 45% of herbaria samples). A species was considered as taxonomically resolved if its members showed at least one diagnostic difference from any other taxon in the study and formed a monophyletic clade. The highest species resolution (69%) was obtained by combining information from all three genes. The joint sequence information for rbcL and matK distinguished 54% of 286 species, while rbcL and ITS2 distinguished 63% of 285 species. Discrimination of species within Salix, which constituted 8% of the flora, was particularly problematic. Despite incomplete resolution, the barcode results revealed 22 misidentified herbarium specimens, and enabled the identification of field specimens which were otherwise too immature to identify. Although seven cases of ITS2 paralogy were noted in the families Cyperaceae, Juncaceae and Juncaginaceae, this intergenic spacer played an important role in resolving congeneric plant species at Churchill. Our results provided fast and cost-effective solution to create a

Diversity, expression and mRNA targeting abilities of Argonaute-targeting miRNAs among selected vascular plants.

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Jagtap, Soham; Shivaprasad, Padubidri V

2014-12-02

Micro (mi)RNAs are important regulators of plant development. Across plant lineages, Dicer-like 1 (DCL1) proteins process long ds-like structures to produce micro (mi) RNA duplexes in a stepwise manner. These miRNAs are incorporated into Argonaute (AGO) proteins and influence expression of RNAs that have sequence complementarity with miRNAs. Expression levels of AGOs are greatly regulated by plants in order to minimize unwarranted perturbations using miRNAs to target mRNAs coding for AGOs. AGOs may also have high promoter specificity-sometimes expression of AGO can be limited to just a few cells in a plant. Viral pathogens utilize various means to counter antiviral roles of AGOs including hijacking the host encoded miRNAs to target AGOs. Two host encoded miRNAs namely miR168 and miR403 that target AGOs have been described in the model plant Arabidopsis and such a mechanism is thought to be well conserved across plants because AGO sequences are well conserved. We show that the interaction between AGO mRNAs and miRNAs is species-specific due to the diversity in sequences of two miRNAs that target AGOs, sequence diversity among corresponding target regions in AGO mRNAs and variable expression levels of these miRNAs among vascular plants. We used miRNA sequences from 68 plant species representing 31 plant families for this analysis. Sequences of miR168 and miR403 are not conserved among plant lineages, but surprisingly they differ drastically in their sequence diversity and expression levels even among closely related plants. Variation in miR168 expression among plants correlates well with secondary structures/length of loop sequences of their precursors. Our data indicates a complex AGO targeting interaction among plant lineages due to miRNA sequence diversity and sequences of miRNA targeting regions among AGO mRNAs, thus leading to the assumption that the perturbations by viruses that use host miRNAs to target antiviral AGOs can only be species-specific. We also show

Genome Analysis of Conserved Dehydrin Motifs in Vascular Plants

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Ahmad A. Malik

2017-05-01

Full Text Available Dehydrins, a large family of abiotic stress proteins, are defined by the presence of a mostly conserved motif known as the K-segment, and may also contain two other conserved motifs known as the Y-segment and S-segment. Using the dehydrin literature, we developed a sequence motif definition of the K-segment, which we used to create a large dataset of dehydrin sequences by searching the Pfam00257 dehydrin dataset and the Phytozome 10 sequences of vascular plants. A comprehensive analysis of these sequences reveals that lysine residues are highly conserved in the K-segment, while the amino acid type is often conserved at other positions. Despite the Y-segment name, the central tyrosine is somewhat conserved, but can be substituted with two other small aromatic amino acids (phenylalanine or histidine. The S-segment contains a series of serine residues, but in some proteins is also preceded by a conserved LHR sequence. In many dehydrins containing all three of these motifs the S-segment is linked to the K-segment by a GXGGRRKK motif (where X can be any amino acid, suggesting a functional linkage between these two motifs. An analysis of the sequences shows that the dehydrin architecture and several biochemical properties (isoelectric point, molecular mass, and hydrophobicity score are dependent on each other, and that some dehydrin architectures are overexpressed during certain abiotic stress, suggesting that they may be optimized for a specific abiotic stress while others are involved in all forms of dehydration stress (drought, cold, and salinity.

A systematic examination of the relationships between CDOM and DOC in inland waters in China

OpenAIRE

K. Song; Y. Zhao; Y. Zhao; Z. Wen; C. Fang; C. Fang; Y. Shang

2017-01-01

Chromophoric dissolved organic matter (CDOM) plays a vital role in the biogeochemical cycle in aquatic ecosystems. The relationship between CDOM and dissolved organic carbon (DOC) has been investigated, and this significant relationship lays the foundation for the estimation of DOC using remotely sensed imagery data. The current study examined samples from freshwater lakes, saline lakes, rivers and streams, urban water bodies, and ice-covered lakes in China for tracking t...

Deconstructing the Effects of Flow on DOC, Nitrate, and Major Ion Interactions Using a High-Frequency Aquatic Sensor Network

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Koenig, L. E.; Shattuck, M. D.; Snyder, L. E.; Potter, J. D.; McDowell, W. H.

2017-12-01

Streams provide a physical linkage between land and downstream river networks, delivering solutes derived from multiple catchment sources. We analyzed high-frequency time series of stream solutes to characterize the timing and magnitude of major ion, nutrient, and organic matter transport over event, seasonal, and annual timescales as well as to assess whether nitrate (NO3-) and dissolved organic carbon (DOC) transport are coupled in catchments, which would be expected if they are subject to similar biogeochemical controls throughout the watershed. Our data set includes in situ observations of NO3-, fluorescent dissolved organic matter (DOC proxy), and specific conductance spanning 2-4 years in 10 streams and rivers across New Hampshire, including observations of nearly 700 individual hydrologic events. We found a positive response of NO3- and DOC to flow in forested streams, but watershed development led to a negative relationship between NO3- and discharge, and thus a decoupling of the overall NO3- and DOC responses to flow. On event and seasonal timescales, NO3- and DOC consistently displayed different behaviors. For example, in several streams, FDOM yield was greatest during summer storms while NO3- yield was greatest during winter storms. Most streams had generalizable storm NO3- and DOC responses, but differences in the timing of NO3- and DOC transport suggest different catchment sources. Further, certain events, including rain-on-snow and summer storms following dry antecedent conditions, yielded disproportionate NO3- responses. High-frequency data allow for increased understanding of the processes controlling solute variability and will help reveal their responses to changing climatic regimes.

North Carolina Seagrass Submersed Rooted Vasculars 1990 Geoform

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National Oceanic and Atmospheric Administration, Department of Commerce — A GIS data set of polygon data interpreted from aerial photography taken by NOAA/NOS Photogrammetry Branch depicting areas of Aquatic Beds of Rooted Vascular Plants...

North Carolina Seagrass Submersed Rooted Vasculars 1990 Substrate

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A GIS data set of polygon data interpreted from aerial photography taken by NOAA/NOS Photogrammetry Branch depicting areas of Aquatic Beds of Rooted Vascular Plants...

North Carolina Seagrass Submersed Rooted Vasculars 1990 Biotic

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A GIS data set of polygon data interpreted from aerial photography taken by NOAA/NOS Photogrammetry Branch depicting areas of Aquatic Beds of Rooted Vascular Plants...

Direct DOC and nitrate determination in water using dual pathlength and second derivative UV spectrophotometry.

Science.gov (United States)

Causse, Jean; Thomas, Olivier; Jung, Aude-Valérie; Thomas, Marie-Florence

2017-01-01

UV spectrophotometry is largely used for water and wastewater quality monitoring. The measurement/estimation of specific and aggregate parameters such as nitrate and dissolved organic carbon (DOC) is possible with UV spectra exploitation, from 2 to multi wavelengths calibration. However, if nitrate determination from UV absorbance is known, major optical interferences linked to the presence of suspended solids, colloids or dissolved organic matter limit the relevance of UV measurement for DOC assessment. A new method based on UV spectrophotometric measurement of raw samples (without filtration) coupling a dual pathlength for spectra acquisition and the second derivative exploitation of the signal is proposed in this work. The determination of nitrate concentration is carried out from the second derivative of the absorbance at 226 nm corresponding at the inflexion point of nitrate signal decrease. A short optical pathlength can be used considering the strong absorption of nitrate ion around 210 nm. For DOC concentration determination the second derivative absorbance at 295 nm is proposed after nitrate correction. Organic matter absorbing slightly in the 270-330 nm window, a long optical pathlength must be selected in order to increase the sensitivity. The method was tested on several hundred of samples from small rivers of two agricultural watersheds located in Brittany, France, taken during dry and wet periods. The comparison between the proposed method and the standardised procedures for nitrate and DOC measurement gave a good adjustment for both parameters for ranges of 2-100 mg/L NO3 and 1-30 mg/L DOC. Copyright © 2016 Elsevier Ltd. All rights reserved.

Land management as a factor controlling dissolved organic carbon release from upland peat soils 2: changes in DOC productivity over four decades.

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Clutterbuck, B; Yallop, A R

2010-11-15

Increasing DOC concentrations in surface waters have been observed across parts of Europe and North America over the past few decades. Most proposed explanations for these widespread trends invoke climate change or reductions in sulphate deposition. However, these factors do not seem apposite to explain either the fine-scale (within kilometres) or regional-scale spatial variation in DOC concentrations observed across the UK. We have reconstructed DOC concentrations and land use for one North Pennine and five South Pennine catchments (UK), located in three discrete areas, over the last four decades. Rainfall, temperature and sulphate deposition data, where available, were also collated and the potential influence of these factors on surface water DOC concentrations was assessed. Four of the six catchments examined showed highly significant (pDOC (hDOC) concentrations in drainage waters over the period 1990-2005. Changes in temperature and sulphate deposition may explain 20-30% of this trend in these four catchments. However, the rapid expansion of new moorland burn on blanket peat can explain a far greater degree (>80%) of the change in hDOC. Far smaller increases in hDOC (10-18%) were identified for the two remaining catchments. These two sites experienced similar changes in sulphur deposition and temperature to those that had seen largest increases in DOC, but contained little or no moorland burn management on blanket peat. This study shows that regional-scale factors undoubtedly underlie some of the recent observed increases in drainage humic coloured DOC. However, changes in land management, in this case the extensive use of fire management on blanket peat, are a far more important driver of increased hDOC release from upland catchments in some parts of the UK. It suggests that the recent rapid increase in the use of burning on blanket peat moorland has implications for ecosystem services and carbon budgets. Copyright © 2010 Elsevier B.V. All rights reserved.

The "DOC" screen: Feasible and valid screening for depression, Obstructive Sleep Apnea (OSA) and cognitive impairment in stroke prevention clinics.

Science.gov (United States)

Swartz, Richard H; Cayley, Megan L; Lanctôt, Krista L; Murray, Brian J; Cohen, Ashley; Thorpe, Kevin E; Sicard, Michelle N; Lien, Karen; Sahlas, Demetrios J; Herrmann, Nathan

2017-01-01

Post-stroke Depression, Obstructive sleep apnea (OSA) and Cognitive impairment ("DOC") are associated with greater mortality, worse recovery and poorer quality of life. Best practice recommendations endorse routine screening for each condition; yet, all are under-assessed, diagnosed and treated. We seek to determine the feasibility and validity of an integrated tool ("DOC" screen) to identify stroke clinic patients at high-risk of depression, OSA, and cognitive impairment. All consecutive new referrals to a regional Stroke Prevention Clinic who were English-speaking and non-aphasic were eligible to be screened. Time for screen completion was logged. DOC screen results were compared to the neuropsychological battery and polysomnogram assessments using a modified receiver operator characteristic and area under the curve analysis. Data is reported to conform to STARD guidelines. 1503 people were screened over 2 years. 89% of eligible patients completed the screen in 5 minutes or less (mean 4.2 minutes), less than half the time it takes to complete the Montreal Cognitive Assessment (MoCA). 437 people consented to detailed testing. Of those, 421 completed the Structured Clinical Interview for Depression within 3 months of screening, 387 completed detailed neuropsychological testing within 3 months, and 88 had overnight polysomnograms. Screening scores combined with demographic variables (age, sex, education, body mass index), had excellent validity compared to gold standard diagnoses: DOC-Mood AUC 0.90; DOC-Apnea AUC 0.80; DOC-Cog AUC 0.81. DOC screen scores can reliably categorize patients in to low-, intermediate- or high-risk groups for further action and can do so with comparable accuracy to more time-consuming screens. Systematic screening of depression, obstructive sleep apnea, and cognitive impairment in 5 minutes or less is feasible and valid in a high volume stroke clinic using the DOC screen. The DOC screen may facilitate improved identification and treatment

Aquatic vascular plants as handicraft: a case study in southern Brazil

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Mabel R. Báez-Lizarazo

2017-11-01

Full Text Available ABSTRACT This study aimed to evaluate knowledge about and the usage and importance of aquatic vascular plants (AVPs in the production of handicrafts by communities on the north coast of the state of Rio Grande do Sul in southern Brazil. The snowball technique was employed to locate people who use and have knowledge regarding the use of AVPs for handicrafts. Data were collected through semi-structured interviews and guided tours with 35 interviewees who were involved in artisanal activity at the time of the study. The data were analyzed using the importance value (IV index and the consensus value for the forms of use (CMU. The Spearman correlation test (rs was employed to determine the correlations of each social variable with the knowledge variables, and Mann-Whitney U tests to verify whether men and women exhibited differences in knowledge. The interviewees cited 16 AVPs that were employed in 17 types of handicrafts, among which the four main species were Schoenoplectus californicus, Typha domingensis, T. latifolia and Androtrichum giganteum. Interviewee age, residence time on site and time working with handicrafts were the main social parameters that described the level of knowledge and use of AVPs. These AVPs reflect cultural knowledge and complement family incomes.

Abundance, stable isotopic composition, and export fluxes of DOC, POC, and DIC from the Lower Mississippi River during 2006–2008

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Cai, Yihua; Guo, Laodong; Wang, Xuri; Aiken, George R.

2015-01-01

Sources, abundance, isotopic compositions, and export fluxes of dissolved inorganic carbon (DIC), dissolved and colloidal organic carbon (DOC and COC), and particulate organic carbon (POC), and their response to hydrologic regimes were examined through monthly sampling from the Lower Mississippi River during 2006–2008. DIC was the most abundant carbon species, followed by POC and DOC. Concentration and δ13C of DIC decreased with increasing river discharge, while those of DOC remained fairly stable. COC comprised 61 ± 3% of the bulk DOC with similar δ13C abundances but higher percentages of hydrophobic organic acids than DOC, suggesting its aromatic and diagenetically younger status. POC showed peak concentrations during medium flooding events and at the rising limb of large flooding events. While δ13C-POC increased, δ15N of particulate nitrogen decreased with increasing discharge. Overall, the differences in δ13C between DOC or DIC and POC show an inverse correlation with river discharge. The higher input of soil organic matter and respired CO2 during wet seasons was likely the main driver for the convergence of δ13C between DIC and DOC or POC, whereas enhanced in situ primary production and respiration during dry seasons might be responsible for their isotopic divergence. Carbon export fluxes from the Mississippi River were estimated to be 13.6 Tg C yr−1 for DIC, 1.88 Tg C yr−1 for DOC, and 2.30 Tg C yr−1 for POC during 2006–2008. The discharge-normalized DIC yield decreased during wet seasons, while those of POC and DOC increased and remained constant, respectively, implying variable responses in carbon export to the increasing discharge.

The first insight into the metabolite profiling of grapes from three Vitis vinifera L. cultivars of two controlled appellation (DOC) regions.

Science.gov (United States)

Teixeira, António; Martins, Viviana; Noronha, Henrique; Eiras-Dias, José; Gerós, Hernâni

2014-03-10

The characterization of the metabolites accumulated in the grapes of specific cultivars grown in different climates is of particular importance for viticulturists and enologists. In the present study, the metabolite profiling of grapes from the cultivars, Alvarinho, Arinto and Padeiro de Basto, of two Portuguese Controlled Denomination of Origin (DOC) regions (Vinho Verde and Lisboa) was investigated by gas chromatography-coupled time-of-flight mass spectrometry (GC-TOF-MS) and an amino acid analyzer. Primary metabolites, including sugars, organic acids and amino acids, and some secondary metabolites were identified. Tartaric and malic acids and free amino acids accumulated more in grapes from vines of the DOC region of Vinho Verde than DOC Lisboa, but a principal component analysis (PCA) plot showed that besides the DOC region, the grape cultivar also accounted for the variance in the relative abundance of metabolites. Grapes from the cultivar, Alvarinho, were particularly rich in malic acid and tartaric acids in both DOC regions, but sucrose accumulated more in the DOC region of Vinho Verde.

The First Insight into the Metabolite Profiling of Grapes from Three Vitis vinifera L. Cultivars of Two Controlled Appellation (DOC Regions

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António Teixeira

2014-03-01

Full Text Available The characterization of the metabolites accumulated in the grapes of specific cultivars grown in different climates is of particular importance for viticulturists and enologists. In the present study, the metabolite profiling of grapes from the cultivars, Alvarinho, Arinto and Padeiro de Basto, of two Portuguese Controlled Denomination of Origin (DOC regions (Vinho Verde and Lisboa was investigated by gas chromatography-coupled time-of-flight mass spectrometry (GC-TOF-MS and an amino acid analyzer. Primary metabolites, including sugars, organic acids and amino acids, and some secondary metabolites were identified. Tartaric and malic acids and free amino acids accumulated more in grapes from vines of the DOC region of Vinho Verde than DOC Lisboa, but a principal component analysis (PCA plot showed that besides the DOC region, the grape cultivar also accounted for the variance in the relative abundance of metabolites. Grapes from the cultivar, Alvarinho, were particularly rich in malic acid and tartaric acids in both DOC regions, but sucrose accumulated more in the DOC region of Vinho Verde.

Reproductive organ and vascular specific promoter of the rice plasma membrane Ca2+ATPase mediates environmental stress responses in plants.

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Huda, Kazi Md Kamrul; Banu, Mst Sufara Akhter; Pathi, Krishna Mohan; Tuteja, Narendra

2013-01-01

Plasma membrane Ca(2+)ATPase is a transport protein in the plasma membrane of cells and helps in removal of calcium (Ca(2+)) from the cell, hence regulating Ca(2+) level within cells. Though plant Ca(2+)ATPases have been shown to be involved in plant stress responses but their promoter regions have not been well studied. The 1478 bp promoter sequence of rice plasma membrane Ca(2+)ATPase contains cis-acting elements responsive to stresses and plant hormones. To identify the functional region, serial deletions of the promoter were fused with the GUS sequence and four constructs were obtained. These were differentially activated under NaCl, PEG cold, methyl viologen, abscisic acid and methyl jasmonate treatments. We demonstrated that the rice plasma membrane Ca(2+)ATPase promoter is responsible for vascular-specific and multiple stress-inducible gene expression. Only full-length promoter showed specific GUS expression under stress conditions in floral parts. High GUS activity was observed in roots with all the promoter constructs. The -1478 to -886 bp flanking region responded well upon treatment with salt and drought. Only the full-length promoter presented cold-induced GUS expression in leaves, while in shoots slight expression was observed for -1210 and -886 bp flanking region. The -1210 bp deletion significantly responded to exogenous methyl viologen and abscisic acid induction. The -1210 and -886 bp flanking region resulted in increased GUS activity in leaves under methyl jasmonate treatments, whereas in shoots the -886 bp and -519 bp deletion gave higher expression. Salicylic acid failed to induce GUS activities in leaves for all the constructs. The rice plasma membrane Ca(2+)ATPase promoter is a reproductive organ-specific as well as vascular-specific. This promoter contains drought, salt, cold, methyl viologen, abscisic acid and methyl jasmonate related cis-elements, which regulated gene expression. Overall, the tissue-specificity and inducible nature of this

Reproductive organ and vascular specific promoter of the rice plasma membrane Ca2+ATPase mediates environmental stress responses in plants.

Directory of Open Access Journals (Sweden)

Kazi Md Kamrul Huda

Full Text Available Plasma membrane Ca(2+ATPase is a transport protein in the plasma membrane of cells and helps in removal of calcium (Ca(2+ from the cell, hence regulating Ca(2+ level within cells. Though plant Ca(2+ATPases have been shown to be involved in plant stress responses but their promoter regions have not been well studied.The 1478 bp promoter sequence of rice plasma membrane Ca(2+ATPase contains cis-acting elements responsive to stresses and plant hormones. To identify the functional region, serial deletions of the promoter were fused with the GUS sequence and four constructs were obtained. These were differentially activated under NaCl, PEG cold, methyl viologen, abscisic acid and methyl jasmonate treatments. We demonstrated that the rice plasma membrane Ca(2+ATPase promoter is responsible for vascular-specific and multiple stress-inducible gene expression. Only full-length promoter showed specific GUS expression under stress conditions in floral parts. High GUS activity was observed in roots with all the promoter constructs. The -1478 to -886 bp flanking region responded well upon treatment with salt and drought. Only the full-length promoter presented cold-induced GUS expression in leaves, while in shoots slight expression was observed for -1210 and -886 bp flanking region. The -1210 bp deletion significantly responded to exogenous methyl viologen and abscisic acid induction. The -1210 and -886 bp flanking region resulted in increased GUS activity in leaves under methyl jasmonate treatments, whereas in shoots the -886 bp and -519 bp deletion gave higher expression. Salicylic acid failed to induce GUS activities in leaves for all the constructs.The rice plasma membrane Ca(2+ATPase promoter is a reproductive organ-specific as well as vascular-specific. This promoter contains drought, salt, cold, methyl viologen, abscisic acid and methyl jasmonate related cis-elements, which regulated gene expression. Overall, the tissue-specificity and inducible

Mapping Surface Water DOC in the Northern Gulf of Mexico Using CDOM Absorption Coefficients and Remote Sensing Imagery

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Kelly, B.; Chelsky, A.; Bulygina, E.; Roberts, B. J.

2017-12-01

Remote sensing techniques have become valuable tools to researchers, providing the capability to measure and visualize important parameters without the need for time or resource intensive sampling trips. Relationships between dissolved organic carbon (DOC), colored dissolved organic matter (CDOM) and spectral data have been used to remotely sense DOC concentrations in riverine systems, however, this approach has not been applied to the northern Gulf of Mexico (GoM) and needs to be tested to determine how accurate these relationships are in riverine-dominated shelf systems. In April, July, and October 2017 we sampled surface water from 80+ sites over an area of 100,000 km2 along the Louisiana-Texas shelf in the northern GoM. DOC concentrations were measured on filtered water samples using a Shimadzu TOC-VCSH analyzer using standard techniques. Additionally, DOC concentrations were estimated from CDOM absorption coefficients of filtered water samples on a UV-Vis spectrophotometer using a modification of the methods of Fichot and Benner (2011). These values were regressed against Landsat visible band spectral data for those same locations to establish a relationship between the spectral data, CDOM absorption coefficients. This allowed us to spatially map CDOM absorption coefficients in the Gulf of Mexico using the Landsat spectral data in GIS. We then used a multiple linear regressions model to derive DOC concentrations from the CDOM absorption coefficients and applied those to our map. This study provides an evaluation of the viability of scaling up CDOM absorption coefficient and remote-sensing derived estimates of DOC concentrations to the scale of the LA-TX shelf ecosystem.

Bioprinting for vascular and vascularized tissue biofabrication.

Science.gov (United States)

Datta, Pallab; Ayan, Bugra; Ozbolat, Ibrahim T

2017-03-15

Bioprinting is a promising technology to fabricate design-specific tissue constructs due to its ability to create complex, heterocellular structures with anatomical precision. Bioprinting enables the deposition of various biologics including growth factors, cells, genes, neo-tissues and extra-cellular matrix-like hydrogels. Benefits of bioprinting have started to make a mark in the fields of tissue engineering, regenerative medicine and pharmaceutics. Specifically, in the field of tissue engineering, the creation of vascularized tissue constructs has remained a principal challenge till date. However, given the myriad advantages over other biofabrication methods, it becomes organic to expect that bioprinting can provide a viable solution for the vascularization problem, and facilitate the clinical translation of tissue engineered constructs. This article provides a comprehensive account of bioprinting of vascular and vascularized tissue constructs. The review is structured as introducing the scope of bioprinting in tissue engineering applications, key vascular anatomical features and then a thorough coverage of 3D bioprinting using extrusion-, droplet- and laser-based bioprinting for fabrication of vascular tissue constructs. The review then provides the reader with the use of bioprinting for obtaining thick vascularized tissues using sacrificial bioink materials. Current challenges are discussed, a comparative evaluation of different bioprinting modalities is presented and future prospects are provided to the reader. Biofabrication of living tissues and organs at the clinically-relevant volumes vitally depends on the integration of vascular network. Despite the great progress in traditional biofabrication approaches, building perfusable hierarchical vascular network is a major challenge. Bioprinting is an emerging technology to fabricate design-specific tissue constructs due to its ability to create complex, heterocellular structures with anatomical precision

Determination of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) in freshwaters by sequential injection spectrophotometry with on-line UV photo-oxidation

International Nuclear Information System (INIS)

Tue-Ngeun, Orawan; Sandford, Richard C.; Jakmunee, Jaroon; Grudpan, Kate; McKelvie, Ian D.; Worsfold, Paul J.

2005-01-01

An automated sequential injection (SI) method for the determination of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) in freshwaters is presented. For DIC measurement on-line sample acidification (sulphuric acid, pH 2 which subsequently diffused through a PTFE membrane into a basic, cresol red acceptor stream. The CO 2 increased the concentration of the acidic form of the cresol red indicator, with a resultant decrease in absorbance at 570 nm being directly proportional to DIC concentration. DIC + DOC was determined after on-line sample irradiation (15 W low power UV lamp) coupled with acid-peroxydisulfate digestion, with the subsequent detection of CO 2 as described above. DOC was determined by subtraction of DIC from (DIC + DOC). Analytical figures of merit were linear ranges of 0.05-5.0 mg C L -1 for both DIC and DIC + DOC, with typical R.S.D.s of less than 7% (0.05 mg C L -1 -5.3% for DIC and 6.6% for DIC + DOC; 4.0 mg C L -1 -2.6% for DIC and 2.4% for DIC + DOC, n = 3) and an LOD (blank + 3S.D.) of 0.05 mg C L -1 . Sample throughput for the automated system was 8 h -1 for DIC and DOC with low reagent consumption (acid/peroxydisulfate 200 μL per DIC + DOC analysis). A range of model carbon compounds and Tamar River (Plymouth, UK) samples were analysed for DIC and DOC and the results showed good agreement with a high temperature catalytic oxidation (HTCO) reference method (t-test, P = 0.05)

Determination of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) in freshwaters by sequential injection spectrophotometry with on-line UV photo-oxidation

Energy Technology Data Exchange (ETDEWEB)

Tue-Ngeun, Orawan [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Sandford, Richard C. [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drakes Circus, Plymouth PL4 8AA (United Kingdom)]. E-mail: rsandford@plymouth.ac.uk; Jakmunee, Jaroon [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Grudpan, Kate [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); McKelvie, Ian D. [Water Studies Centre, School of Chemistry, Monash University, P.O. Box 23, Clayton Campus, Vic. 3800 (Australia); Worsfold, Paul J. [School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drakes Circus, Plymouth PL4 8AA (United Kingdom)

2005-12-04

An automated sequential injection (SI) method for the determination of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) in freshwaters is presented. For DIC measurement on-line sample acidification (sulphuric acid, pH < 2), converted DIC to CO{sub 2} which subsequently diffused through a PTFE membrane into a basic, cresol red acceptor stream. The CO{sub 2} increased the concentration of the acidic form of the cresol red indicator, with a resultant decrease in absorbance at 570 nm being directly proportional to DIC concentration. DIC + DOC was determined after on-line sample irradiation (15 W low power UV lamp) coupled with acid-peroxydisulfate digestion, with the subsequent detection of CO{sub 2} as described above. DOC was determined by subtraction of DIC from (DIC + DOC). Analytical figures of merit were linear ranges of 0.05-5.0 mg C L{sup -1} for both DIC and DIC + DOC, with typical R.S.D.s of less than 7% (0.05 mg C L{sup -1}-5.3% for DIC and 6.6% for DIC + DOC; 4.0 mg C L{sup -1}-2.6% for DIC and 2.4% for DIC + DOC, n = 3) and an LOD (blank + 3S.D.) of 0.05 mg C L{sup -1}. Sample throughput for the automated system was 8 h{sup -1} for DIC and DOC with low reagent consumption (acid/peroxydisulfate 200 {mu}L per DIC + DOC analysis). A range of model carbon compounds and Tamar River (Plymouth, UK) samples were analysed for DIC and DOC and the results showed good agreement with a high temperature catalytic oxidation (HTCO) reference method (t-test, P = 0.05)

Increased dissolved organic carbon (DOC) in Central European streams is driven by reductions in ionic strength rather than climate change or decreasing acidity.

Science.gov (United States)

Hruska, Jakub; Krám, Pavel; McDowell, William H; Oulehle, Filip

2009-06-15

Temporal trends in DOC concentration and flux were investigated at two geochemically distinct forested catchments in western Czech Republic. Mean discharge-weighted DOC concentrations averaged 18.8 mg L(-1) at the acidic Lysina catchment, and 20.2 mg L(-1) at base-rich and well-buffered Pluhuv Bor. Between 1993 and 2007 DOC in streamwater increased significantly in both catchments: the mean annual increase was 0.42 mg L(-1) yr(-1) (p DOC were correlated with only modest increases in stream pH in both catchments, but large declines in ionic strength (IS), that resulted from declining atmospheric deposition. Neither catchment has undergone changes in soil-water pH, yet DOC concentrations tripled in the soil-water of both catchments. We conclude that changes in ionic strength of soil-water and streamwater, rather than acidity, are the primary drivers of changes in streamwater DOC in this region. Temperature, precipitation and discharge show no statistically significant trends during the study period, suggesting that climate change has played no role in the changes in DOC that we have observed.

78 FR 36506 - Notice of Request for Extension of Approval of an Information Collection; Importation of Plants...

Science.gov (United States)

2013-06-18

... 2013. Kevin Shea, Acting Administrator, Animal and Plant Health Inspection Service. [FR Doc. 2013-14466... DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service [Docket No. APHIS-2013-0035] Notice of Request for Extension of Approval of an Information Collection; Importation of Plants for...

TOC/DOC: "It Has Changed the Way I Do Science".

Science.gov (United States)

Douglas, Kimberly; Roth, Dana L.

1997-01-01

Describes a user-based automated service developed at the California Institute of Technology that combines access to journal article databases with an in-house document delivery system. TOC/DOC (Tables of Contents/Document Delivery) has undergone a conceptual change from a catalog of locally-held journal articles to a broader, more retrospective…

Experimental study on the particulate matter and nitrogenous compounds from diesel engine retrofitted with DOC+CDPF+SCR

Science.gov (United States)

Zhang, Yunhua; Lou, Diming; Tan, Piqiang; Hu, Zhiyuan

2018-03-01

The increasingly stringent emission regulations will mandate the retrofit of after-treatment devices for in-use diesel vehicles, in order to reduce their substantial particulate matter and nitrogen oxides (NOX) emissions. In this paper, a combination of DOC (diesel oxidation catalyst), CDPF (catalytic diesel particulate filter) and SCR (selective catalytic reduction) retrofit for a heavy-duty diesel engine was employed to perform experiment on the engine test bench to evaluate the effects on the particulate matter emissions including particle number (PN), particle mass (PM), particle size distributions and nitrogenous compounds emissions including NOX, nitrogen dioxide (NO2)/NOX, nitrous oxide (N2O) and ammonia (NH3) slip. In addition, the urea injection was also of our concern. The results showed that the DOC+CDPF+SCR retrofit almost had no adverse effect on the engine power and fuel consumption. Under the test loads, the upstream DOC and CDPF reduced the PN and PM by an average of 91.6% and 90.9%, respectively. While the downstream SCR brought about an average decrease of 85% NOX. Both PM and NOX emission factors based on this retrofit were lower than China-Ⅳ limits (ESC), and even lower than China-Ⅴ limits (ESC) at medium and high loads. The DOC and CDPF changed the particle size distributions, leading to the increase in the proportion of accumulation mode particles and the decrease in the percentage of nuclear mode particles. This indicates that the effect of DOC and CDPF on nuclear mode particles was better than that of accumulation mode ones. The upstream DOC could increase the NO2/NOX ratio to 40%, higher NO2/NOX ratio improved the efficiency of CDPF and SCR. Besides, the N2O emission increased by an average of 2.58 times after the retrofit and NH3 slip occurred with the average of 26.7 ppm. The rate of urea injection was roughly equal to 8% of the fuel consumption rate. The DOC+CDPF+SCR retrofit was proved a feasible and effective measurement in terms

Viscosity changes of riparian water controls diurnal fluctuations of stream-flow and DOC concentration

Science.gov (United States)

Schwab, Michael; Klaus, Julian; Pfister, Laurent; Weiler, Markus

2015-04-01

Diurnal fluctuations in stream-flow are commonly explained as being triggered by the daily evapotranspiration cycle in the riparian zone, leading to stream flow minima in the afternoon. While this trigger effect must necessarily be constrained by the extent of the growing season of vegetation, we here show evidence of daily stream flow maxima in the afternoon in a small headwater stream during the dormant season. We hypothesize that the afternoon maxima in stream flow are induced by viscosity changes of riparian water that is caused by diurnal temperature variations of the near surface groundwater in the riparian zone. The patterns were observed in the Weierbach headwater catchment in Luxembourg. The catchment is covering an area of 0.45 km2, is entirely covered by forest and is dominated by a schistous substratum. DOC concentration at the outlet of the catchment was measured with the field deployable UV-Vis spectrometer spectro::lyser (scan Messtechnik GmbH) with a high frequency of 15 minutes over several months. Discharge was measured with an ISCO 4120 Flow Logger. During the growing season, stream flow shows a frequently observed diurnal pattern with discharge minima in the afternoon. During the dormant season, a long dry period with daily air temperature amplitudes of around 10 ° C occurred in March and April 2014, with discharge maxima in the afternoon. The daily air temperature amplitude led to diurnal variations in the water temperature of the upper 10 cm of the riparian zone. Higher riparian water temperatures cause a decrease in water viscosity and according to the Hagen-Poiseuille equation, the volumetric flow rate is inversely proportional to viscosity. Based on the Hagen-Poiseuille equation and the viscosity changes of water, we calculated higher flow rates of near surface groundwater through the riparian zone into the stream in the afternoon which explains the stream flow maxima in the afternoon. With the start of the growing season, the viscosity

Effect of moisture and temperature variation on DOC release from a peatland: conflicting results from laboratory, field and historical data analysis.

Science.gov (United States)

Preston, Michael D; Eimers, M Catherine; Watmough, Shaun A

2011-03-01

Peatlands are large repositories of atmospheric carbon and concern has been raised over the stability of this carbon store because increasing dissolved organic carbon (DOC) concentrations have been observed in peatland drainage waters. A number of potential causes have been proposed in the literature, and conflicting results among studies conducted at different spatial and temporal scales suggest that the methodological approach may be an important confounding factor. The objective of this study was to determine the influence of moisture and temperature on DOC release from a south-central Ontario peatland during the fall (a major export period) following three commonly used approaches: laboratory microcosms, an intensive field study and analysis of long-term data (1980-2008). The effect of variations in temperature and moisture differed among microcosm, field study and analysis of the long-term record. Water content was important at the microcosm scale as DOC concentration and aromaticity increased with peat water-saturation. Drought caused a decrease in DOC concentration and pH, and an increase in sulphate and base cation concentrations. In contrast, the field study indicated that DOC concentration was strongly associated with temperature, and weakly correlated (negatively) with stream discharge. Average fall DOC concentration (but not export) increased over the 29 year record, and was correlated with fall discharge and precipitation (negative) and summer precipitation and fall stream pH (positive). As no common strong predictor of fall DOC was found at three scales of investigation at a single, well-studied site, it may be unreasonable to expect to identify a universal driver behind the widespread increase in DOC concentration. Copyright © 2010 Elsevier B.V. All rights reserved.

Role of hormones in controlling vascular differentiation and the mechanism of lateral root initiation.

Science.gov (United States)

Aloni, Roni

2013-11-01

The vascular system in plants is induced and controlled by streams of inductive hormonal signals. Auxin produced in young leaves is the primary controlling signal in vascular differentiation. Its polar and non-polar transport pathways and major controlling mechanisms are clarified. Ethylene produced in differentiating protoxylem vessels is the signal that triggers lateral root initiation, while tumor-induced ethylene is a limiting and controlling factor of crown gall development and its vascular differentiation. Gibberellin produced in mature leaves moves non-polarly and promotes elongation, regulates cambium activity and induces long fibers. Cytokinin from the root cap moves upward to promote cambial activity and stimulate shoot growth and branching, while strigolactone from the root inhibits branching. Furthermore, the role of the hormonal signals in controlling the type of differentiating vascular elements and gradients of conduit size and density, and how they regulate plant adaptation and have shaped wood evolution are elucidated.

Targeted delivery of miR-200c/DOC to inhibit cancer stem cells and cancer cells by the gelatinases-stimuli nanoparticles.

Science.gov (United States)

Liu, Qin; Li, Ru-Tian; Qian, Han-Qing; Wei, Jia; Xie, Li; Shen, Jie; Yang, Mi; Qian, Xiao-Ping; Yu, Li-Xia; Jiang, Xi-Qun; Liu, Bao-Rui

2013-09-01

Cancer stem cells (CSCs) are recently discovered as vital obstacles for the successful cancer therapy. Emerging evidences suggest that miR-200c functions as an effective CSCs inhibitor and can restore sensitivity to microtubule-targeting drugs. In the present work, the intelligent gelatinases-stimuli nanoparticles (NPs) was set up to co-deliver miR-200c and docetaxel (DOC) to verify their synergetic effects on inhibition of CSCs and non-CSC cancer cells. After tumor cells were treated with miR-200c NPs, miR-200c and its targeted gene class III beta-tubulin (TUBB3)TUBB3 expression were evaluated. The effects of miR-200c/DOC NPs on tumor cell viability, migration and invasion as well as the expression of E-cadherin and CD44 were studied. The antitumor effects of miR-200c/DOC NPs were compared with DOC NPs in xenograft gastric cancer mice. Moreover, the residual tumors after treatment were subcutaneously seeded into nude mice to further investigate the effective maintenance of NPs. We found that the gelatinases-stimuli NPs facilitated miR-200c into cells, achieving sustained miR-200c expression in tumor cells during 9 days. The miR-200c/DOC NPs significantly enhanced cytotoxicity of DOC, possibly by decreasing TUBB3 level, and reversing EMT. The miR-200c NPs achieved high levels of in vivo accumulation and long retention in gastric cancer xenografts after intravenous administration. The miR-200c/DOC NPs prominently suppressed in vivo tumor growth with elevated miR-200c and E-cadherin levels and down-regulated TUBB3 and CD44 expressions. When the residual tumors after miR-200c/DOC NPs treatment were re-transplanted into nude mice, the tumors demonstrated the slowest growth speed. The miR-200c/DOC NPs may provide a promising modality for co-delivery of nucleic acid and drugs to simultaneously inhibit CSCs and non-CSC cancer cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fluorescence measured in situ as a proxy of CDOM absorption and DOC concentration in the Baltic Sea

Directory of Open Access Journals (Sweden)

Piotr Kowalczuk

2010-09-01

Full Text Available This study presents results from field surveys performed in 2008 and 2009 in the southern Baltic in different seasons. The main goal of these measurements was to identify the empirical relationships between DOM optical properties and DOC. CDOM absorption and fluorescence and DOC concentrations were measured during thirteen research cruises. The values of the CDOM absorption coefficient at 370 nm aCDOM(370 ranged from 0.70 m-1 to 7.94 m-1, and CDOM fluorescence intensities (ex./em. 370/460 IFl, expressed in quinine sulphate equivalent units, ranged from 3.88 to 122.97 (in filtered samples. Dissolved organic carbon (DOC concentrations ranged from 266.7 to 831.7 µM C. There was a statistically significant linear relationship between the fluorescence intensity measured in the filtered samples and the CDOM absorption coefficient aCDOM(370, R2 = 0.87. There was much more scatter in the relationship between the fluorescence intensity measured in situ (i.e. in unprocessed water samples and the CDOM absorption coefficient aCDOM(370, resulting in a slight deterioration in the coefficient of determination R2 = 0.85. This indicated that the presence of particles could impact fluorometer output during in situ deployment. A calibration experiment was set up to quantify particle impact on the instrument output in raw marine water samples relative to readings from filtered samples. The bias calculated for the absolute percentage difference between fluorescence intensities measured in raw and filtered water was low (-2.05%, but the effect of particle presence expressed as the value of the RMSE was significant and was as high as 35%. Both DOM fluorescence intensity (in raw water and filtered samples and the CDOM absorption coefficient aCDOM(370 are highly correlated with DOC concentration. The relationship between DOC and the CDOM absorption coefficient aCDOM(370 was better (R2 = 0.76 than the relationship between DOC and the respective fluorescence intensities

Derivation of the physical equations solved in the inertial confinement stability code DOC. Informal report

International Nuclear Information System (INIS)

Scannapieco, A.J.; Cranfill, C.W.

1978-11-01

There now exists an inertial confinement stability code called DOC, which runs as a postprocessor. DOC (a code that has evolved from a previous code, PANSY) is a spherical harmonic linear stability code that integrates, in time, a set of Lagrangian perturbation equations. Effects due to real equations of state, asymmetric energy deposition, thermal conduction, shock propagation, and a time-dependent zeroth-order state are handled in the code. We present here a detailed derivation of the physical equations that are solved in the code

Derivation of the physical equations solved in the inertial confinement stability code DOC. Informal report

Energy Technology Data Exchange (ETDEWEB)

Scannapieco, A.J.; Cranfill, C.W.

1978-11-01

There now exists an inertial confinement stability code called DOC, which runs as a postprocessor. DOC (a code that has evolved from a previous code, PANSY) is a spherical harmonic linear stability code that integrates, in time, a set of Lagrangian perturbation equations. Effects due to real equations of state, asymmetric energy deposition, thermal conduction, shock propagation, and a time-dependent zeroth-order state are handled in the code. We present here a detailed derivation of the physical equations that are solved in the code.

Understanding the relationship between DOC and nitrate export and dominant rainfall-runoff processes through long-term high frequency measurements

Science.gov (United States)

Schwab, Michael; Klaus, Julian; Pfister, Laurent; Weiler, Markus

2016-04-01

Over the past decades, stream sampling protocols for hydro-geochemical parameters were often limited by logistical and technological constraints. While long-term monitoring protocols were typically based on weekly sampling intervals, high frequency sampling was commonly limited to a few single events. In our study, we combined high frequency and long-term measurements to understand the DOC and nitrate behaviour and dynamics for different runoff events and seasons. Our study area is the forested Weierbach catchment (0.47 km2) in Luxembourg. The fractured schist bedrock is covered by cambisol soils. The runoff response of the catchment is characterized by a double peak behaviour. A first discharge peak occurs during or right after a rainfall event (triggered by fast near surface runoff generation processes), while a second delayed peak lasts several days (generated by subsurface flow/ shallow groundwater flow). Peaks in DOC concentrations are closely linked to the first discharge peak, whereas nitrate concentrations follow the second peak. Our observations were carried out with the field deployable instrument spectro::lyser (scan Messtechnik GmbH). This instrument relies on the principles of UV-Vis spectrometry and measures DOC and nitrate concentrations. The measurements were carried out at a high frequency of 15 minutes in situ in the Weierbach creek for more than two years. In addition, a long-term validation was carried out with data obtained from the analysis of water collected with automatic samplers. The long-term, high-frequency measurements allowed us to calculate a complete and detailed balance of DOC and nitrate export over two years. Transport behaviour of the DOC and nitrate showed different dynamics between the first and second hydrograph peaks. DOC is mainly exported during first peaks, while nitrate is mostly exported during the delayed second peaks. In combination with other measurements in the catchment, the long and detailed observations have

Rapid response of hydrological loss of DOC to water table drawdown and warming in Zoige peatland: results from a mesocosm experiment.

Science.gov (United States)

Lou, Xue-Dong; Zhai, Sheng-Qiang; Kang, Bing; Hu, Ya-Lin; Hu, Li-Le

2014-01-01

A large portion of the global carbon pool is stored in peatlands, which are sensitive to a changing environment conditions. The hydrological loss of dissolved organic carbon (DOC) is believed to play a key role in determining the carbon balance in peatlands. Zoige peatland, the largest peat store in China, is experiencing climatic warming and drying as well as experiencing severe artificial drainage. Using a fully crossed factorial design, we experimentally manipulated temperature and controlled the water tables in large mesocosms containing intact peat monoliths. Specifically, we determined the impact of warming and water table position on the hydrological loss of DOC, the exported amounts, concentrations and qualities of DOC, and the discharge volume in Zoige peatland. Our results revealed that of the water table position had a greater impact on DOC export than the warming treatment, which showed no interactive effects with the water table treatment. Both DOC concentration and discharge volume were significantly increased when water table drawdown, while only the DOC concentration was significantly promoted by warming treatment. Annual DOC export was increased by 69% and 102% when the water table, controlled at 0 cm, was experimentally lowered by -10 cm and -20 cm. Increases in colored and aromatic constituents of DOC (measured by Abs(254 nm), SUVA(254 nm), Abs(400 nm), and SUVA(400 nm)) were observed under the lower water tables and at the higher peat temperature. Our results provide an indication of the potential impacts of climatic change and anthropogenic drainage on the carbon cycle and/or water storage in a peatland and simultaneously imply the likelihood of potential damage to downstream ecosystems. Furthermore, our results highlight the need for local protection and sustainable development, as well as suggest that more research is required to better understand the impacts of climatic change and artificial disturbances on peatland degradation.

Rapid response of hydrological loss of DOC to water table drawdown and warming in Zoige peatland: results from a mesocosm experiment.

Directory of Open Access Journals (Sweden)

Xue-Dong Lou

Full Text Available A large portion of the global carbon pool is stored in peatlands, which are sensitive to a changing environment conditions. The hydrological loss of dissolved organic carbon (DOC is believed to play a key role in determining the carbon balance in peatlands. Zoige peatland, the largest peat store in China, is experiencing climatic warming and drying as well as experiencing severe artificial drainage. Using a fully crossed factorial design, we experimentally manipulated temperature and controlled the water tables in large mesocosms containing intact peat monoliths. Specifically, we determined the impact of warming and water table position on the hydrological loss of DOC, the exported amounts, concentrations and qualities of DOC, and the discharge volume in Zoige peatland. Our results revealed that of the water table position had a greater impact on DOC export than the warming treatment, which showed no interactive effects with the water table treatment. Both DOC concentration and discharge volume were significantly increased when water table drawdown, while only the DOC concentration was significantly promoted by warming treatment. Annual DOC export was increased by 69% and 102% when the water table, controlled at 0 cm, was experimentally lowered by -10 cm and -20 cm. Increases in colored and aromatic constituents of DOC (measured by Abs(254 nm, SUVA(254 nm, Abs(400 nm, and SUVA(400 nm were observed under the lower water tables and at the higher peat temperature. Our results provide an indication of the potential impacts of climatic change and anthropogenic drainage on the carbon cycle and/or water storage in a peatland and simultaneously imply the likelihood of potential damage to downstream ecosystems. Furthermore, our results highlight the need for local protection and sustainable development, as well as suggest that more research is required to better understand the impacts of climatic change and artificial disturbances on peatland degradation.

Light absorption properties of colored dissolved organic matter (CDOM) in adjacent waters of the Changjiang Estuary during a flood season: implication for DOC estimation

Science.gov (United States)

Liu, Yangyang; Shen, Fang; Li, Xiuzhen

2014-11-01

Light absorption properties of colored dissolved organic matter (CDOM) in adjacent waters of the Changjiang Estuary were investigated during the summer of 2013. CDOM absorption showed a substantial portion of the total absorption and clearly dominant among most investigation stations. It generally decreased from the northwest to the southeast, which controlled by physical mixing of fresh water and seawater as was indicated by a conservative behaviour of CDOM. CDOM absorption sharply increased during phytoplankton blooms. Similarly, dissolved organic carbon (DOC) also peaked during blooms period. However, DOC exhibited a more complex behavior relative to a simple conservative mixing, possibly attributed to multiple origins of DOC. CDOM absorption and DOC co-varied to some degree, implying a potential way of DOC estimation from CDOM absorption. However, more detailed information such as CDOM and DOC composition and more validation data were required to obtain a stable CDOM - DOC pattern. Lastly, empirical algorithms with limited data were developed to retrieve CDOM absorption. Further validation of the algorithms were needed when they were to be commonly applied.

PanMetaDocs - A tool for collecting and managing the long tail of "small science data"

Science.gov (United States)

Klump, J.; Ulbricht, D.

2011-12-01

In the early days of thinking about cyberinfrastructure the focus was on "big science data". Today, the challenge is not anymore to store several terabytes of data, but to manage data objects in a way that facilitates their re-use. Key to re-use by a user as a data consumer is proper documentation of the data. Also, data consumers need discovery metadata to find the data they need and they need descriptive metadata to be able to use the data they retrieved. Thus, data documentation faces the challenge to extensively and completely describe these objects, hold the items easily accessible at a sustainable cost level. However, data curation and documentation do not rank high in the everyday work of a scientist as a data producer. Data producers are often frustrated by being asked to provide metadata on their data over and over again, information that seemed very obvious from the context of their work. A challenge to data archives is the wide variety of metadata schemata in use, which creates a number of maintenance and design challenges of its own. PanMetaDocs addresses these issues by allowing an uploaded files to be described by more than one metadata object. PanMetaDocs, which was developed from PanMetaWorks, is a PHP based web application that allow to describe data with any xml-based metadata schema. Its user interface is browser based and was developed to collect metadata and data in collaborative scientific projects situated at one or more institutions. The metadata fields can be filled with static or dynamic content to reduce the number of fields that require manual entries to a minimum and make use of contextual information in a project setting. In the development of PanMetaDocs the business logic of panMetaWorks is reused, except for the authentication and data management functions of PanMetaWorks, which are delegated to the eSciDoc framework. The eSciDoc repository framework is designed as a service oriented architecture that can be controlled through a

Ecologic and geographic distributions of the vascular plants of southern Nye County, and adjacent parts of Clark, Lincoln, and Esmeralda Counties, Nevada. [Based on collections made in 1970

Energy Technology Data Exchange (ETDEWEB)

Beatley, J. C.

1971-01-01

A catalog is compiled of the vascular plants indiginous to Nye, Clark, Lincoln, and Esmeralda Counties of Nevada based on collections made in 1970. This compilation is an update of previous collections in these areas and is a supplement to report, UCLA--12-705. (ERB)

Correlates of monoicy and dioicy in hornworts, the apparent sister group to vascular plants.

Science.gov (United States)

Villarreal, Juan Carlos; Renner, Susanne S

2013-11-02

Whether male and female gametes are produced by single or separate individuals shapes plant mating and hence patterns of genetic diversity among and within populations. Haploid-dominant plants ("bryophytes": liverworts, mosses and hornworts) can have unisexual (dioicous) or bisexual (monoicous) gametophytes, and today, 68% of liverwort species, 57% of moss species, and 40% of hornwort species are dioicous. The transitions between the two sexual systems and possible correlations with other traits have been studied in liverworts and mosses, but not hornworts. Here we use a phylogeny for 98 of the 200 species of hornworts, the sister group to vascular plants, representing roughly equal proportions of all monoicous and all dioicous species, to test whether transitions in sexual systems are predominantly from monoicy to dioicy as might be expected based on studies of mosses. We further investigate possible correlations between sexual system and spore size, antheridium number, ploidy level, and diversification rate, with character selection partly based on findings in mosses and liverworts. Hornworts underwent numerous transitions between monoicy and dioicy. The transition rate from dioicy to monoicy was 2× higher than in the opposite direction, but monoicous groups have higher extinction rates; diversification rates do not correlate with sexual system. A correlation important in mosses, that between monoicy and polyploidy, apparently plays a small role: of 20 species with chromosome counts, only one is polyploid, the monoicous Anthoceros punctatus. A contingency test revealed that transitions to dioicy were more likely in species with small spores, supporting the hypothesis that small but numerous spores may be advantageous for dioicous species that depend on dense carpets of gametophytes for reproductive assurance. However, we found no evidence for increased antheridium-per-chamber numbers in dioicous species. Sexual systems in hornworts are labile, and the higher

Hydraulic efficiency and safety of vascular and non-vascular components in Pinus pinaster leaves.

Science.gov (United States)

Charra-Vaskou, Katline; Badel, Eric; Burlett, Régis; Cochard, Hervé; Delzon, Sylvain; Mayr, Stefan

2012-09-01

Leaves, the distal section of the soil-plant-atmosphere continuum, exhibit the lowest water potentials in a plant. In contrast to angiosperm leaves, knowledge of the hydraulic architecture of conifer needles is scant. We investigated the hydraulic efficiency and safety of Pinus pinaster needles, comparing different techniques. The xylem hydraulic conductivity (k(s)) and embolism vulnerability (P(50)) of both needle and stem were measured using the cavitron technique. The conductance and vulnerability of whole needles were measured via rehydration kinetics, and Cryo-SEM and 3D X-ray microtomographic observations were used as reference tools to validate physical measurements. The needle xylem of P. pinaster had lower hydraulic efficiency (k(s) = 2.0 × 10(-4) m(2) MPa(-1) s(-1)) and safety (P(50) = - 1.5 MPa) than stem xylem (k(s) = 7.7 × 10(-4) m(2) MPa(-1) s(-1); P(50) = - 3.6 to - 3.2 MPa). P(50) of whole needles (both extra-vascular and vascular pathways) was - 0.5 MPa, suggesting that non-vascular tissues were more vulnerable than the xylem. During dehydration to - 3.5 MPa, collapse and embolism in xylem tracheids, and gap formation in surrounding tissues were observed. However, a discrepancy in hydraulic and acoustic results appeared compared with visualizations, arguing for greater caution with these techniques when applied to needles. Our results indicate that the most distal parts of the water transport pathway are limiting for hydraulics of P. pinaster. Needle tissues exhibit a low hydraulic efficiency and low hydraulic safety, but may also act to buffer short-term water deficits, thus preventing xylem embolism.

Simulation of low temperature combustion mechanism of different combustion-supporting agents in close-coupled DOC and DPF system.

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Jiao, Penghao; Li, Zhijun; Li, Qiang; Zhang, Wen; He, Li; Wu, Yue

2018-07-01

In the coupled Diesel Oxidation Catalyst (DOC) and Diesel Particular Filter (DPF) system, soot cannot be completely removed by only using the passive regeneration. And DPF active regeneration is necessary. The research method in this paper is to spray different kinds of combustion-supporting agents to the DOC in the front of the DPF. Therefore, the low temperature combustion mechanism of different kinds of combustion-supporting agents in DOC was studied, in order to grasp the law of combustion in DOC, and the influence of follow-up emission on DPF removal of soot. During the study, CH 4 H 2 mixture and diesel (n-heptane + toluene) were used as combustion-supporting agents respectively. The simplified mechanisms of two kinds of gas mixtures used as the combustion-supporting agents in DPF have been constructed and testified in the paper. In this paper, the combustion and emission conditions of the two combustion-supporting agents were analyzed so as to meet the practical requirements of different working conditions. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Deposition and light absorption characteristics of precipitation dissolved organic carbon (DOC) at three remote stations in the Himalayas and Tibetan Plateau, China.

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Li, Chaoliu; Yan, Fangping; Kang, Shichang; Chen, Pengfei; Hu, Zhaofu; Han, Xiaowen; Zhang, Guoshuai; Gao, Shaopeng; Qu, Bin; Sillanpää, Mika

2017-12-15

The concentrations, depositions and optical properties of precipitation DOC at three remote stations (Nam Co, Lulang and Everest) were investigated in the Himalayas and Tibetan Plateau (HTP). The results showed that their volume-weighted mean DOC concentrations were 1.05±1.01mgCL -1 , 0.83±0.85mgCL -1 and 0.86±0.91mgCL -1 , respectively, close to those of other remote areas in the world and lower than those of typical polluted urban cities. Combined with precipitation amounts, the DOC depositions at these three stations were calculated to be 0.34±0.32gCm -2 yr -1 , 0.84±0.86gCm -2 yr -1 and 0.16±0.17gCm -2 yr -1 , respectively. The annual DOC deposition in the HTP was approximately 0.94±0.87TgC, the highest and lowest values appeared in the southeastern and northwestern plateau, respectively. The sources of DOC in the precipitation at these three stations were remarkably different, indicating large spatial heterogeneity in the sources of precipitation DOC over the HTP. Nam Co presented combustion sources from South Asia and local residents, Lulang showed biomass combustion source from South Asia, and Everest was mainly influenced by local mineral dust. The values of the MAC DOC at 365nm were 0.48±0.47m 2 g -1 , 0.25±0.15m 2 g -1 , and 0.64±0.49m 2 g -1 , respectively, for the precipitation at the three stations. All of these values were significantly lower than those of corresponding near-surface aerosol samples because precipitation DOC contains more secondary organic aerosol with low light absorption abilities. Additionally, this phenomenon was also observed in seriously polluted urban areas, implying it is universal in the atmosphere. Because precipitation DOC contains information for both particle-bound and gaseous components from the near surface up to the altitude of clouds where precipitation occurs, the MAC DOC of precipitation is more representative than that of near-surface aerosols for a given region. Copyright © 2017 Elsevier B.V. All rights

The vascular plants: open system of growth.

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Basile, Alice; Fambrini, Marco; Pugliesi, Claudio

2017-03-01

What is fascinating in plants (true also in sessile animals such as corals and hydroids) is definitely their open and indeterminate growth, as a result of meristematic activity. Plants as well as animals are characterized by a multicellular organization, with which they share a common set of genes inherited from a common eukaryotic ancestor; nevertheless, circa 1.5 billion years of evolutionary history made the two kingdoms very different in their own developmental biology. Flowering plants, also known as angiosperms, arose during the Cretaceous Period (145-65 million years ago), and up to date, they count around 235,000 species, representing the largest and most diverse group within the plant kingdom. One of the foundations of their success relies on the plant-pollinator relationship, essentially unique to angiosperms that pushed large speciation in both plants and insects and on the presence of the carpel, the structure devoted to seed enclosure. A seed represents the main organ preserving the genetic information of a plant; during embryogenesis, the primary axis of development is established by two groups of pluripotent cells: the shoot apical meristem (SAM), responsible for gene rating all aboveground organs, and the root apical meristem (RAM), responsible for producing all underground organs. During postembryonic shoot development, axillary meristem (AM) initiation and outgrowth are responsible for producing all secondary axes of growth including inflorescence branches or flowers. The production of AMs is tightly linked to the production of leaves and their separation from SAM. As leaf primordia are formed on the flanks of the SAM, a region between the apex and the developing organ is established and referred to as boundary zone. Interaction between hormones and the gene network in the boundary zone is fundamental for AM initiation. AMs only develop at the adaxial base of the leaf; thus, AM initiation is also strictly associated with leaf polarity. AMs

Plasma 11-deoxycorticosterone (DOC) and mineralocorticoid receptor testicular expression during rainbow trout Oncorhynchus mykiss spermiation: implication with 17alpha, 20beta-dihydroxyprogesterone on the milt fluidity?

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Milla, Sylvain; Terrien, Xavier; Sturm, Armin; Ibrahim, Fidaa; Giton, Franck; Fiet, Jean; Prunet, Patrick; Le Gac, Florence

2008-05-19

In rainbow trout (Oncorhynchus mykiss), the endocrine control of spermiation is not fully understood. Besides 11ketotestosterone (11KT) and 17alpha, 20beta-dihydroxyprogesterone (MIS), the potential physiological ligand of the mineralocorticoid receptor (MR) 11-deoxycorticosterone (DOC), is a credible candidate in O. mykiss spermiation regulation as spermiation is accompanied with changes in aqueous and ionic flows. In this study, we investigated potential roles of DOC during spermiation 1) by describing changes in blood plasma DOC level, MR mRNA abundance during the reproductive cycle and MR localization in the reproductive tract 2) by investigating and comparing the effects of DOC (10 mg/kg) and MIS (5 mg/kg) supplementations on sperm parameters 3) by measuring the in vitro effect of DOC on testis MIS production. The plasma concentration of DOC increased rapidly at the end of the reproductive cycle to reach levels that were 10-50 fold higher in mature males than in immature fish. MR mRNA relative abundance was lower in maturing testes when compared to immature testes, but increased rapidly during the spermiation period, immediately after the plasma rise in DOC. At this stage, immunohistochemistry localized MR protein to cells situated at the periphery of the seminiferous tubules and in the efferent ducts. Neither DOC nor MIS had significant effects on the mean sperm volume, although MIS treatment significantly increased the percentage of males producing milt. However, a significant reduction in the spermatocrit was observed when DOC and MIS were administrated together. Finally, we detected an inhibitory effect of DOC on testis MIS production in vitro. These results are in agreement with potential roles of DOC and MR during spermiation and support the hypothesis that DOC and MIS mechanisms of action are linked during this reproductive stage, maybe controlling milt fluidity. They also confirm that in O. mykiss MIS is involved in spermiation induction.

Land management as a factor controlling dissolved organic carbon release from upland peat soils 1: spatial variation in DOC productivity.

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Yallop, A R; Clutterbuck, B

2009-06-01

The importance of soil storage in global carbon cycling is well recognised and factors leading to increased losses from this pool may act as a positive feedback mechanism in global warming. Upland peat soils are usually assumed to serve as carbon sinks, there is however increasing evidence of carbon loss from upland peat soils, and DOC concentrations in UK rivers have increased markedly over the past three decades. A number of drivers for increasing DOC release from peat soils have been proposed although many of these would not explain fine-scale variations in DOC release observed in many catchments. We examined the effect of land use and management on DOC production in upland peat catchments at two spatial scales within the UK. DOC concentration was measured in streams draining 50 small-scale catchments (b3 km2) in three discrete regions of the south Pennines and one area in the North Yorkshire Moors. Annual mean DOC concentration was also derived from water colour data recorded at water treatment works for seven larger scale catchments (1.5-20 km2) in the south Pennines. Soil type and land use/management in all catchments were characterised from NSRI digital soil data and ortho-corrected colour aerial imagery. Of the factors assessed, representing all combinations of soil type and land use together with catchment slope and area, the proportion of exposed peat surface resulting from new heather burning was consistently identified as the most significant predictor of variation in DOC concentration. This relationship held across all blanket peat catchments and scales. We propose that management activities are driving changes in edaphic conditions in upland peat to those more favourable for aerobic microbial activity and thus enhance peat decomposition leading to increased losses of carbon from these environments.

Four-year-BS-position-paper.pdf | misc docs | academy | Indian ...

Indian Academy of Sciences (India)

Home; academy; misc docs; Four-year-BS-position-paper.pdf. 404! error. The page your are looking for can not be found! Please check the link or use the navigation bar at the top. YouTube; Twitter; Facebook; Blog. Academy News. IAS Logo. 29th Mid-year meeting. Posted on 19 January 2018. The 29th Mid-year meeting of ...

The effect of environmental change on vascular plant and cryptogam communities from the Falkland Islands and the Maritime Antarctic

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Convey Peter

2007-12-01

Full Text Available Abstract Background Antarctic terrestrial vegetation is subject to one of the most extreme climates on Earth. Currently, parts of Antarctica are one of the fastest warming regions on the planet. During 3 growing seasons, we investigated the effect of experimental warming on the diversity and abundance of coastal plant communities in the Maritime Antarctic region (cryptogams only and the Falkland Islands (vascular plants only. We compared communities from the Falkland Islands (51°S, mean annual temperature 7.9°C, with those of Signy Island (60°S, -2.1°C and Anchorage Island (67°S, -2.6°C, and experimental temperature manipulations at each of the three islands using Open Top Chambers (OTCs. Results Despite the strong difference in plant growth form dominance between the Falkland Islands and the Maritime Antarctic, communities across the gradient did not differ in total diversity and species number. During the summer months, the experimental temperature increase at 5 cm height in the vegetation was similar between the locations (0.7°C across the study. In general, the response to this experimental warming was low. Total lichen cover showed a non-significant decreasing trend at Signy Island (p Conclusion These results suggest that small temperature increases may rapidly lead to decreased soil moisture, resulting in more stressful conditions for plants. The more open plant communities (grass and lichen appeared more negatively affected by such changes than dense communities (dwarf shrub and moss.

Vascular flora and geoecology of Mont de la Table, Gaspesie, Quebec

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Scott W. Bailey; Joann Hoy; Charles V. Cogbill

2015-01-01

The influence of substrate lithology on the distribution of many vascular and nonvascular plants has long been recognized, especially in alpine, subalpine, and other rocky habitats. In particular, plants have been classified as dependent on high-calcium substrates (i.e., calcicoles) based on common restriction to habitats developed in calcareous rocks, such as...

Sources and fate of organic (DOC, POC, CDOM) and inorganic (DIC) carbon in a mangrove dominated estuary (French Guiana)

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Ray, R.; Michaud, E.; Vantrepotte, V.; Aller, R. C.; Morvan, S.; Thouzeau, G.

2016-12-01

We studied the mangrove dominated Sinnamary estuarine system in French Guiana during the dry and wet seasons in 2015 to examine the sources, transport and fate of surface water DOC, POC and DIC along the salinity gradient and the effect of tidal fluctuations on carbon dynamics. Elemental ratios, stable isotopes and optical properties (absorption) were applied as proxies to delineate the sources and molecular structure of the organic carbon. Results showed that during the wet season there were significant net inputs of POC and DOC along the salinity gradient from mangroves and enhanced surface runoff. Time series performed during the dry season at a station in channel water adjacent to mangroves revealed mangrove-derived export and exchanges of DOC and POC during the ebb and marine algae import during the flood. DOC was the dominant form of carbon in both seasons with DOC:POC ratios typically between 13 and 40. Both δ13DOC and CDOM descriptors (e.g., S275-295 and a*412) confirmed mangrove litter leaching to be the primary contributor of high molecular weight dissolved organic matter in the wet season which was replaced by marine phytoplanktonic OC during transport offshore in the dry season. CDOM aromaticity is lower in the dry season as mangrove inputs decrease. POC showed similar trends as DOC, with maximum contributions of terrestrial litter in the river and mixing zone, and in situ production dominant in the marine zone. The entire estuary is heterotrophic, exhibiting high pCO2 (837-5575µatm) and oxygen undersaturation (59-86%) in both seasons, and substantial CO2 emission fluxes (278-3671mmol m-2 d-1). Intense local remineralization and laterally transported CO2 originating from mangrove benthic respiration could account for the water column pCO2 enrichment during low tide and night time. Keywords: Organic carbon, stable isotopes, CDOM, pCO2, mangrove, French Guiana

Microarray Data Analysis of Space Grown Arabidopsis Leaves for Genes Important in Vascular Patterning

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Weitzeal, A. J.; Wyatt, S. E.; Parsons-Wingerter, P.

2016-01-01

Venation patterning in leaves is a major determinant of photosynthesis efficiency because of its dependency on vascular transport of photoassimilates, water, and minerals. Arabidopsis thaliana grown in microgravity show delayed growth and leaf maturation. Gene expression data from the roots, hypocotyl, and leaves of A. thaliana grown during spaceflight vs. ground control analyzed by Affymetrix microarray are available through NASAs GeneLab (GLDS-7). We analyzed the data for differential expression of genes in leaves resulting from the effects of spaceflight on vascular patterning. Two genes were found by preliminary analysis to be upregulated during spaceflight that may be related to vascular formation. The genes are responsible for coding an ARGOS like protein (potentially affecting cell elongation in the leaves), and an F-boxkelch-repeat protein (possibly contributing to protoxylem specification). Further analysis that will focus on raw data quality assessment and a moderated t-test may further confirm upregulation of the two genes and/or identify other gene candidates. Plants defective in these genes will then be assessed for phenotype by the mapping and quantification of leaf vascular patterning by NASAs VESsel GENeration (VESGEN) software to model specific vascular differences of plants grown in spaceflight.

15 CFR 20.1 - The purpose of DOC's age discrimination regulations.

Science.gov (United States)

2010-01-01

... NONDISCRIMINATION ON THE BASIS OF AGE IN PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE General § 20... basis of age in programs or activities receiving Federal financial assistance. The Act and the general... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false The purpose of DOC's age...

A review of plant-based compounds and medicinal plants effective on atherosclerosis

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Mehrnoosh Sedighi

2017-01-01

Full Text Available Atherosclerosis is one of the most important cardiovascular diseases that involve vessels through the development of fatty streaks and plaques. Plant-based compounds can help treat or prevent atherosclerosis through affecting the involved factors. The main purpose of this review article is to investigate and introduce medicinal plants and their potential activities regarding antioxidant properties, effective on lipids level and development of plaque, atherosclerosis, and progression of atherosclerosis as well as the development of cardiovascular disease and ischemia. To search for the relevant articles indexed in Information Sciences Institute, PubMed, Scientific Information Database, IranMedex, and Scopus between 1980 and 2013, with further emphasis on those indexed from 2004 to 2015, we used these search terms: atherosclerosis, antioxidant, cholesterol, inflammation, and the medicinal plants below. Then, the articles with inclusion criteria were used in the final analysis of the findings. Plant-based active compounds, including phenols, flavonoids, and antioxidants, can be effective on atherosclerosis predisposing factors and hence in preventing this disease and associated harmful complications, especially through reducing cholesterol, preventing increase in free radicals, and ultimately decreasing vascular plaque and vascular resistance. Hence, medicinal plants can contribute to treating atherosclerosis and preventing its progression through reducing cholesterolemia, free radicals, inflammation, vascular resistance, and certain enzymes. They, alone or in combination with hypocholesterolemic drugs, can therefore be useful for patients with hyperlipidemia and its complications.

UV-visible absorbance spectroscopy as a proxy for peatland dissolved organic carbon (DOC) quantity and quality: considerations on wavelength and absorbance degradation.

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Peacock, Mike; Evans, Chris D; Fenner, Nathalie; Freeman, Chris; Gough, Rachel; Jones, Timothy G; Lebron, Inma

2014-05-01

Absorbance in the UV or visible spectrum (UV-vis) is commonly used as a proxy for DOC concentrations in waters draining upland catchments. To determine the appropriateness of different UV-vis measurements we used surface and pore water samples from two Welsh peatlands in four different experiments: (i) an assessment of single wavelength proxies (1 nm increments between 230-800 nm) for DOC concentration demonstrated that 254 nm was more accurate than 400 nm. The highest R(2) values between absorbance and DOC concentration were generated using 263 nm for one sample set (R(2) = 0.91), and 230 nm for the other three sample sets (respective R(2) values of 0.86, 0.81, and 0.93). (ii) A comparison of different DOC concentration proxies, including single wavelength proxies, a two wavelength model, a proxy using phenolic concentration, and a proxy using the area under a UV spectrum at 250-350 nm. It was found that both a single wavelength proxy (≤263 nm) and a two wavelength model performed well for both pore water and surface water. (iii) An evaluation of the E2 : E3, E2 : E4, E4 : E6 ratios, and SUVA (absorbance at 254 nm normalised to DOC concentration) as indicators of DOC quality showed that the E4 : E6 ratio was subject to extensive variation over time, and was highly correlated between surface water and pore water, suggesting that it is a useful metric to determine temporal changes in DOC quality. (iv) A repeated weekly analysis over twelve weeks showed no consistent change in UV-vis absorbance, and therefore an inferred lack of degradation of total DOC in samples that were filtered and stored in the dark at 4 °C.

Characterization of midrib vascular bundles of selected medicinal species in Rubiaceae

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Nurul-Syahirah, M.; Noraini, T.; Latiff, A.

2016-11-01

An anatomical study was carried out on mature leaves of five selected medicinal species of Rubiaceae from Peninsular Malaysia. The chosen medicinal species were Aidia densiflora, Aidia racemosa, Chasallia chartacea, Hedyotis auricularia and Ixora grandifolia. The objective of this study is to determine the taxonomic value of midrib anatomical characteristics. Leaves samples were collected from Taman Paku Pakis, Universiti Kebangsaan Malaysia, Bangi, Selangor and Kledang Saiong Forest Reserve, Perak, Malaysia. Leaves samples then were fixed in spirit and acetic acid (3:1), the midrib parts then were sectioned using sliding microtome, cleared using Clorox, stained in Safranin and Alcian blue, mounted in Euparal and were observed under light microscope. Findings in this study have shown all species have collateral bundles. The midrib vascular bundles characteristics that can be used as tool to differentiate between species or genus are vascular bundles system (opened or closed), shape and arrangement of main vascular bundles, presence of both additional and medullary vascular bundles, position of additional vascular bundles, shape of medullary vascular bundles, presence of sclerenchyma cells ensheathed the vascular bundles. As a conclusion, midrib anatomical characteristics can be used to identify and discriminate medicinal plants species studied in the Rubiaceae.

Co-ordination of physiological and morphological responses of stomata to elevated [CO2] in vascular plants.

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Haworth, Matthew; Elliott-Kingston, Caroline; McElwain, Jennifer C

2013-01-01

Plant stomata display a wide range of short-term behavioural and long-term morphological responses to atmospheric carbon dioxide concentration ([CO(2)]). The diversity of responses suggests that plants may have different strategies for controlling gas exchange, yet it is not known whether these strategies are co-ordinated in some way. Here, we test the hypothesis that there is co-ordination of physiological (via aperture change) and morphological (via stomatal density change) control of gas exchange by plants. We examined the response of stomatal conductance (G(s)) to instantaneous changes in external [CO(2)] (C(a)) in an evolutionary cross-section of vascular plants grown in atmospheres of elevated [CO(2)] (1,500 ppm) and sub-ambient [O(2)] (13.0 %) compared to control conditions (380 ppm CO(2), 20.9 % O(2)). We found that active control of stomatal aperture to [CO(2)] above current ambient levels was not restricted to angiosperms, occurring in the gymnosperms Lepidozamia peroffskyana and Nageia nagi. The angiosperm species analysed appeared to possess a greater respiratory demand for stomatal movement than gymnosperm species displaying active stomatal control. Those species with little or no control of stomatal aperture (termed passive) to C(a) were more likely to exhibit a reduction in stomatal density than species with active stomatal control when grown in atmospheres of elevated [CO(2)]. The relationship between the degree of stomatal aperture control to C(a) above ambient and the extent of any reduction in stomatal density may suggest the co-ordination of physiological and morphological responses of stomata to [CO(2)] in the optimisation of water use efficiency. This trade-off between stomatal control strategies may have developed due to selective pressures exerted by the costs associated with passive and active stomatal control.

TogoDoc server/client system: smart recommendation and efficient management of life science literature.

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Wataru Iwasaki

Full Text Available In this paper, we describe a server/client literature management system specialized for the life science domain, the TogoDoc system (Togo, pronounced Toe-Go, is a romanization of a Japanese word for integration. The server and the client program cooperate closely over the Internet to provide life scientists with an effective literature recommendation service and efficient literature management. The content-based and personalized literature recommendation helps researchers to isolate interesting papers from the "tsunami" of literature, in which, on average, more than one biomedical paper is added to MEDLINE every minute. Because researchers these days need to cover updates of much wider topics to generate hypotheses using massive datasets obtained from public databases or omics experiments, the importance of having an effective literature recommendation service is rising. The automatic recommendation is based on the content of personal literature libraries of electronic PDF papers. The client program automatically analyzes these files, which are sometimes deeply buried in storage disks of researchers' personal computers. Just saving PDF papers to the designated folders makes the client program automatically analyze and retrieve metadata, rename file names, synchronize the data to the server, and receive the recommendation lists of newly published papers, thus accomplishing effortless literature management. In addition, the tag suggestion and associative search functions are provided for easy classification of and access to past papers (researchers who read many papers sometimes only vaguely remember or completely forget what they read in the past. The TogoDoc system is available for both Windows and Mac OS X and is free. The TogoDoc Client software is available at http://tdc.cb.k.u-tokyo.ac.jp/, and the TogoDoc server is available at https://docman.dbcls.jp/pubmed_recom.

TogoDoc server/client system: smart recommendation and efficient management of life science literature.

Science.gov (United States)

Iwasaki, Wataru; Yamamoto, Yasunori; Takagi, Toshihisa

2010-12-13

In this paper, we describe a server/client literature management system specialized for the life science domain, the TogoDoc system (Togo, pronounced Toe-Go, is a romanization of a Japanese word for integration). The server and the client program cooperate closely over the Internet to provide life scientists with an effective literature recommendation service and efficient literature management. The content-based and personalized literature recommendation helps researchers to isolate interesting papers from the "tsunami" of literature, in which, on average, more than one biomedical paper is added to MEDLINE every minute. Because researchers these days need to cover updates of much wider topics to generate hypotheses using massive datasets obtained from public databases or omics experiments, the importance of having an effective literature recommendation service is rising. The automatic recommendation is based on the content of personal literature libraries of electronic PDF papers. The client program automatically analyzes these files, which are sometimes deeply buried in storage disks of researchers' personal computers. Just saving PDF papers to the designated folders makes the client program automatically analyze and retrieve metadata, rename file names, synchronize the data to the server, and receive the recommendation lists of newly published papers, thus accomplishing effortless literature management. In addition, the tag suggestion and associative search functions are provided for easy classification of and access to past papers (researchers who read many papers sometimes only vaguely remember or completely forget what they read in the past). The TogoDoc system is available for both Windows and Mac OS X and is free. The TogoDoc Client software is available at http://tdc.cb.k.u-tokyo.ac.jp/, and the TogoDoc server is available at https://docman.dbcls.jp/pubmed_recom.

'Ike Wai Professional Development Model for Students and Post-docs

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Bruno, B. C.

2016-12-01

'Ike Wai: Securing Hawaii's Water Future, funded by NSF EPSCoR, is an interdisciplinary research collaboration among geophysicists, geochemists, engineers, microbiologists, computational modelers, data scientists and social scientists. Key questions include: How much water is there? How does it flow? How long will it last? Undergraduate students, graduate students and post-docs are actively involved in the research, and their professional development is a key part of the project. An underlying principle is that students assume responsibility for their own learning and professional development. Based on the model created by the NSF Center for Microbial Oceanography: Research and Education (C-MORE) (Bruno et al, 2008; Guannel et al 2014, Bottjer et al 2014), the 'Ike Wai professional development program includes (1) Leadership. Each student and post-doc creates an Individualized Professional Development plan, which includes leadership training (provided by external facilitators) and assuming leadership roles (such as developing and implementing trainings for their peers). (2) EDventures. Based on the C-MORE model, EDventures combines proposal-writing training with the incentive of seed money. Rather than providing training a priori, the EDventures model encourages students and post-docs to write a proposal based on guidelines provided. Training occurs during a two-stage review stage: proposers respond to panel reviews and resubmit their proposal within a single review cycle. C-MORE EDventures alumni self-report statistically significant confidence gains on all questions posed. Their subsequent proposal success is envious: of the 12 proposals submitted by to NSF, 50% were funded. (Wood Charlson & Bruno, 2015) (3) Layered Mentoring Network. All ´Ike Wai participants serve as both mentor and mentee. Students are matched with a non-research mentor in addition to their advisor to promote a holistic approach to career development. They will also serve as mentors to more

Decreasing DOC trends in soil solution along the hillslopes at two IM sites in southern Sweden--geochemical modeling of organic matter solubility during acidification recovery.

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Löfgren, Stefan; Gustafsson, Jon Petter; Bringmark, Lage

2010-12-01

Numerous studies report increased concentrations of dissolved organic carbon (DOC) during the last two decades in boreal lakes and streams in Europe and North America. Recently, a hypothesis was presented on how various spatial and temporal factors affect the DOC dynamics. It was concluded that declining sulphur deposition and thereby increased DOC solubility, is the most important driver for the long-term DOC concentration trends in surface waters. If this recovery hypothesis is correct, the DOC levels should increase both in the soil solution as well as in the surrounding surface waters as soil pH rises and the ionic strength declines due to the reduced input of SO(4)(2-) ions. In this project a geochemical model was set up to calculate the net humic charge and DOC solubility trends in soils during the period 1996-2007 at two integrated monitoring sites in southern Sweden, showing clear signs of acidification recovery. The Stockholm Humic Model was used to investigate whether the observed DOC solubility is related to the humic charge and to examine how pH and ionic strength influence it. Soil water data from recharge and discharge areas, covering both podzols and riparian soils, were used. The model exercise showed that the increased net charge following the pH increase was in many cases counteracted by a decreased ionic strength, which acted to decrease the net charge and hence the DOC solubility. Thus, the recovery from acidification does not necessarily have to generate increasing DOC trends in soil solution. Depending on changes in pH, ionic strength and soil Al pools, the trends might be positive, negative or indifferent. Due to the high hydraulic connectivity with the streams, the explanations to the DOC trends in surface waters should be searched for in discharge areas and peat lands. Copyright © 2010 Elsevier B.V. All rights reserved.

Major Vascular Neurocognitive Disorder: A Reappraisal to Vascular Dementia

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Emre Kumral

2017-03-01

Full Text Available Major vascular neurocognitive disorder (NCD is the second leading form of dementia after Alzheimer’s disease, accounting for 17-20% of all dementias. Vascular NCD is a progressive disease caused by reduced cerebral blood flow related to multiple large volume or lacunar infarcts that induce a sudden onset and stepwise decline in cognitive abilities. Despite its prevalence and clinical importance, there is still controversy in the terminology of vascular NCD. Only after the release of Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5 (2013 did the American Psychiatric Association define vascular dementia as “major vascular NCD”. This review includes an overview of risk factors, pathophysiology, types, diagnostic and clinical features of major vascular NCD, and current treatment options of vascular NCD regarding to DSM-5 criteria

Microarray Data Analysis of Space Grown Arabidopsis Leaves for Genes Important in Vascular Patterning. Analysis of Space Grown Arabidopsis with Microarray Data from GeneLab: Identification of Genes Important in Vascular Patterning

Science.gov (United States)

Weitzel, A. J.; Wyatt, S. E.; Parsons-Wingerter, P.

2016-01-01

Venation patterning in leaves is a major determinant of photosynthesis efficiency because of its dependency on vascular transport of photo-assimilates, water, and minerals. Arabidopsis thaliana grown in microgravity show delayed growth and leaf maturation. Gene expression data from the roots, hypocotyl, and leaves of A. thaliana grown during spaceflight vs. ground control analyzed by Affymetrix microarray are available through NASA's GeneLab (GLDS-7). We analyzed the data for differential expression of genes in leaves resulting from the effects of spaceflight on vascular patterning. Two genes were found by preliminary analysis to be up-regulated during spaceflight that may be related to vascular formation. The genes are responsible for coding an ARGOS (Auxin-Regulated Gene Involved in Organ Size)-like protein (potentially affecting cell elongation in the leaves), and an F-box/kelch-repeat protein (possibly contributing to protoxylem specification). Further analysis that will focus on raw data quality assessment and a moderated t-test may further confirm up-regulation of the two genes and/or identify other gene candidates. Plants defective in these genes will then be assessed for phenotype by the mapping and quantification of leaf vascular patterning by NASA's VESsel GENeration (VESGEN) software to model specific vascular differences of plants grown in spaceflight.

DOC1-Dependent Recruitment of NURD Reveals Antagonism with SWI/SNF during Epithelial-Mesenchymal Transition in Oral Cancer Cells

Directory of Open Access Journals (Sweden)

Adone Mohd-Sarip

2017-07-01

Full Text Available The Nucleosome Remodeling and Deacetylase (NURD complex is a key regulator of cell differentiation that has also been implicated in tumorigenesis. Loss of the NURD subunit Deleted in Oral Cancer 1 (DOC1 is associated with human oral squamous cell carcinomas (OSCCs. Here, we show that restoration of DOC1 expression in OSCC cells leads to a reversal of epithelial-mesenchymal transition (EMT. This is caused by the DOC1-dependent targeting of NURD to repress key transcriptional regulators of EMT. NURD recruitment drives extensive epigenetic reprogramming, including eviction of the SWI/SNF remodeler, formation of inaccessible chromatin, H3K27 deacetylation, and binding of PRC2 and KDM1A, followed by H3K27 methylation and H3K4 demethylation. Strikingly, depletion of SWI/SNF mimics the effects of DOC1 re-expression. Our results suggest that SWI/SNF and NURD function antagonistically to control chromatin state and transcription. We propose that disturbance of this dynamic equilibrium may lead to defects in gene expression that promote oncogenesis.

panMetaDocs, eSciDoc, and DOIDB—An Infrastructure for the Curation and Publication of File-Based Datasets for GFZ Data Services

Directory of Open Access Journals (Sweden)

Damian Ulbricht

2016-03-01

Full Text Available The GFZ German Research Centre for Geosciences is the national laboratory for Geosciences in Germany. As part of the Helmholtz Association, providing and maintaining large-scale scientific infrastructures are an essential part of GFZ activities. This includes the generation of significant volumes and numbers of research data, which subsequently become source materials for data publications. The development and maintenance of data systems is a key component of GFZ Data Services to support state-of-the-art research. A challenge lies not only in the diversity of scientific subjects and communities, but also in different types and manifestations of how data are managed by research groups and individual scientists. The data repository of GFZ Data Services provides a flexible IT infrastructure for data storage and publication, including minting of digital object identifiers (DOI. It was built as a modular system of several independent software components linked together through Application Programming Interfaces (APIs provided by the eSciDoc framework. Principal application software are panMetaDocs for data management and DOIDB for logging and moderating data publications activities. Wherever possible, existing software solutions were integrated or adapted. A summary of our experiences made in operating this service is given. Data are described through comprehensive landing pages and supplementary documents, like journal articles or data reports, thus augmenting the scientific usability of the service.

Seasonal estimates of DOC standing stocks in Apalachicola Bay estuary: Towards a better understanding using field, ocean color and model data

Science.gov (United States)

D'Sa, E. J.; Joshi, I.; Osburn, C. L.; Bianchi, T. S.; Ko, D. S.; Oviedo-Vargas, D.; Arellano, A.; Ward, N.

2016-12-01

Apalachicola Bay, a semi-enclosed estuary located in Florida's panhandle, is well known for its water quality and oyster yields. We present the use of combined field and ocean color satellite observations and the outputs of a high-resolution hydrodynamic model to study the influence of physical processes on the distribution and the transport of terrestrially derived CDOM and DOC to shelf waters during the spring and fall of 2015. Determination of DOC stocks were based on the development of a CDOM algorithm (R2 = 0.87, N = 9) for the VIIRS ocean color sensor, and the assessment of CDOM - DOC relationships (R2 = 0.88, N = 13 in March; R2 = 0.83, N = 24 in November) for the Apalachicola Bay. Satellite-derived CDOM and DOC maps together with model-based salinity distributions revealed their spatial extent, sources and transport to the shelf water. Furthermore, strong seasonal influence on DOM distribution in the bay was associated with inputs from Apalachicola and Carrabelle Rivers and the surrounding marshes. Estimates of DOC standing stocks in the bay obtained using ocean color data and high-resolution bathymetry showed relatively higher stocks in November ( 3.71 × 106 kg C, 560 km2) than in March ( 4.07 × 106 kg C, 560 km2) despite lower river discharge in dry season. Results of DOC flux estimates from the bay to coastal waters will also be presented.

The drivers of plant diversity

DEFF Research Database (Denmark)

Jensen, Kristine Engemann

dataset consisting of 72,533 vascular plant species in 432 families covering the New World. Eight plant growth forms were defined based on woodiness, structure, and root traits, and species names were standardized to the latest accepted scientific name. The data is used in Paper II and IV In Paper II we....... The study emphasise that using big, collected datasets is not without limitations, and we recommend using rarefaction for species richness estimation from such datasets. Paper IV investigates a well-known macroecological pattern, the latitudinal diversity gradient, for nine vascular plant functional groups......In this thesis we use a “big data” approach to describe and explain large-scale patterns of plant diversity. The botanical data used for the six papers come from three different databases covering the New World, North America, and Europe respectively. The data on plant distributions were combined...

Additive Manufacturing of Vascular Grafts and Vascularized Tissue Constructs.

Science.gov (United States)

Elomaa, Laura; Yang, Yunzhi Peter

2017-10-01

There is a great need for engineered vascular grafts among patients with cardiovascular diseases who are in need of bypass therapy and lack autologous healthy blood vessels. In addition, because of the severe worldwide shortage of organ donors, there is an increasing need for engineered vascularized tissue constructs as an alternative to organ transplants. Additive manufacturing (AM) offers great advantages and flexibility of fabrication of cell-laden, multimaterial, and anatomically shaped vascular grafts and vascularized tissue constructs. Various inkjet-, extrusion-, and photocrosslinking-based AM techniques have been applied to the fabrication of both self-standing vascular grafts and porous, vascularized tissue constructs. This review discusses the state-of-the-art research on the use of AM for vascular applications and the key criteria for biomaterials in the AM of both acellular and cellular constructs. We envision that new smart printing materials that can adapt to their environment and encourage rapid endothelialization and remodeling will be the key factor in the future for the successful AM of personalized and dynamic vascular tissue applications.

High-frequency DOC and nitrate measurements provide new insights into their export and their relationships to rainfall-runoff processes

Science.gov (United States)

Schwab, Michael; Klaus, Julian; Pfister, Laurent; Weiler, Markus

2015-04-01

Over the past decades, stream sampling protocols for environmental tracers were often limited by logistical and technological constraints. Long-term sampling programs would typically rely on weekly sampling campaigns, while high-frequency sampling would remain restricted to a few days or hours at best. We stipulate that the currently predominant sampling protocols are too coarse to capture and understand the full amplitude of rainfall-runoff processes and its relation to water quality fluctuations. Weekly sampling protocols are not suited to get insights into the hydrological system during high flow conditions. Likewise, high frequency measurements of a few isolated events do not allow grasping inter-event variability in contributions and processes. Our working hypothesis is based on the potential of a new generation of field-deployable instruments for measuring environmental tracers at high temporal frequencies over an extended period. With this new generation of instruments we expect to gain new insights into rainfall-runoff dynamics, both at intra- and inter-event scales. Here, we present the results of one year of DOC and nitrate measurements with the field deployable UV-Vis spectrometer spectro::lyser (scan Messtechnik GmbH). The instrument measures the absorption spectrum from 220 to 720 nm in situ and at high frequencies and derives DOC and nitrate concentrations. The measurements were carried out at 15 minutes intervals in the Weierbach catchment (0.47 km2) in Luxemburg. This fully forested catchment is characterized by cambisol soils and fractured schist as underlying bedrock. The time series of DOC and nitrate give insights into the high frequency dynamics of stream water. Peaks in DOC concentrations are closely linked to discharge peaks that occur during or right after a rainfall event. Those first discharge peaks can be linked to fast near surface runoff processes and are responsible for a remarkable amount of DOC export. A special characterisation of

Large-scale proteome comparative analysis of developing rhizomes of the ancient vascular plant Equisetum hyemale.

Directory of Open Access Journals (Sweden)

Tiago Santana Balbuena

2012-06-01

Full Text Available Equisetum hyemale is a widespread vascular plant species, whose reproduction is mainly dependent on the growth and development of the rhizomes. Due to its key evolutionary position, the identification of factors that could be involved in the existence of the rhizomatous trait may contribute to a better understanding of the role of this underground organ for the successful propagation of this and other plant species. In the present work, we characterized the proteome of E. hyemale rhizomes using a GeLC-MS spectral-counting proteomics strategy. A total of 1,911 and 1,860 non-redundant proteins were identified in the rhizomes apical tip and elongation zone, respectively. Rhizome- characteristic proteins were determined by comparisons of the developing rhizome tissues to developing roots. A total of 87 proteins were found to be up-regulated in both E. hyemale rhizome tissues in relation to developing roots. Hierarchical clustering indicated a vast dynamic range in the expression of the 87 characteristic proteins and revealed, based on the expression profile, the existence of 9 major protein groups. Gene ontology analyses suggested an over-representation of the terms involved in macromolecular and protein biosynthetic processes, gene expression and nucleotide and protein binding functions. Spatial differences analysis between the rhizome apical tip and the elongation zone revealed that only eight proteins were up-regulated in the apical tip including RNA-binding proteins and an acyl carrier protein, as well as a KH-domain protein and a T-complex subunit; while only seven proteins were up-regulated in the elongation zone including phosphomannomutase, galactomannan galactosyltransferase, endoglucanase 10 and 25 and mannose-1-phosphate guanyltransferase subunits alpha and beta. This is the first large scale characterization of the proteome of a plant rhizome. Implications of the findings were discussed in relation to other underground organs and related

STS-82 Pilot Scott J. 'Doc' Horowitz Suit Up

Science.gov (United States)

1997-01-01

STS-82 Pilot Scott J. 'Doc' Horowitz puts on a glove of his launch and entry suit with assistance from a suit technician in the Operations and Checkout Building. This is Horowitz''';s second space flight. He and the six other crew members will depart shortly for Launch Pad 39A, where the Space Shuttle Discovery awaits liftoff on a 10-day mission to service the orbiting Hubble Space Telescope (HST). This will be the second HST servicing mission. Four back-to-back spacewalks are planned.

Fluorescence measured in situ as a proxy of CDOM absorption and DOC concentration in the Baltic Sea

OpenAIRE

Piotr Kowalczuk; Monika Zabłocka; Sławomir Sagan; Karol Kuliński

2010-01-01

This study presents results from field surveys performed in 2008 and 2009 in the southern Baltic in different seasons. The main goal of these measurements was to identify the empirical relationships between DOM optical properties and DOC. CDOM absorption and fluorescence and DOC concentrations were measured during thirteen research cruises. The values of the CDOM absorption coefficient at 370 nm aCDOM(370) ranged from 0.70 m-1 to 7.94 m-1, and CDOM fluorescence intensities (ex./em. 370/460) I...

Vascular flora of Kenya, based on the Flora of Tropical East Africa

Directory of Open Access Journals (Sweden)

Yadong Zhou

2017-11-01

Full Text Available Kenya, an African country with major higher plant diversity, has a corresponding diversity of plant associations, because of the wide geographic distribution, diverse climatic conditions and soil types. In this article, all vascular plants of Kenya were counted based on the completed "Flora of Tropical East Africa (FTEA", and all families and genera were revised using recent molecular systematics research, forming a "Synoptic List of Families and Genera of Kenyan Vascular Plants (SLFGKVP". In total, there are 225 families, 1538 genera and 6293 indigenous species and and 62 families, 302 genera and 588 exotic species in Kenya. The Fabaceae with 98 genera and 576 Species is the largest family. Two of the seven plant distribution regions of Kenya, K4 and K7 are the most species-richest areas with regard to both total and endemic species, with 3375 and 3191 total species and 174 and 185 endemic species in K4 and K7 respectively. While, K3 and K5 have the highest density of both total and endemic species. K1 has the lowest density of total species, and K2 has the lowest density of endemic species.

Ecology of the Nevada Test Site. I. Geographic and ecologic distributions of the vascular flora (annotated checklist)

Energy Technology Data Exchange (ETDEWEB)

Beatley, J C

1965-04-01

A checklist of vascular plants of the Nevada Test Site is presented for use in studies of plant ecology. Data on the occurrence and distribution of plant species are included. Collections were made from both undisturbed and disturbed sites.

Predicting Vascular Plant Diversity in Anthropogenic Peatlands: Comparison of Modeling Methods with Free Satellite Data

Directory of Open Access Journals (Sweden)

Ivan Castillo-Riffart

2017-07-01

Full Text Available Peatlands are ecosystems of great relevance, because they have an important number of ecological functions that provide many services to mankind. However, studies focusing on plant diversity, addressed from the remote sensing perspective, are still scarce in these environments. In the present study, predictions of vascular plant richness and diversity were performed in three anthropogenic peatlands on Chiloé Island, Chile, using free satellite data from the sensors OLI, ASTER, and MSI. Also, we compared the suitability of these sensors using two modeling methods: random forest (RF and the generalized linear model (GLM. As predictors for the empirical models, we used the spectral bands, vegetation indices and textural metrics. Variable importance was estimated using recursive feature elimination (RFE. Fourteen out of the 17 predictors chosen by RFE were textural metrics, demonstrating the importance of the spatial context to predict species richness and diversity. Non-significant differences were found between the algorithms; however, the GLM models often showed slightly better results than the RF. Predictions obtained by the different satellite sensors did not show significant differences; nevertheless, the best models were obtained with ASTER (richness: R2 = 0.62 and %RMSE = 17.2, diversity: R2 = 0.71 and %RMSE = 20.2, obtained with RF and GLM respectively, followed by OLI and MSI. Diversity obtained higher accuracies than richness; nonetheless, accurate predictions were achieved for both, demonstrating the potential of free satellite data for the prediction of relevant community characteristics in anthropogenic peatland ecosystems.

Using Eco-hydrologic modeling in the Penobscot River Watershed to explore the role of climate and land use change on DOC concentration and flux

Science.gov (United States)

Rouhani, S. F. B. B.; Schaaf, C.; Douglas, E. M.; Huntington, T. G.; Kim, J.

2017-12-01

Dissolved Organic Carbon leaches from the terrestrial watersheds to serve as one of the largest sources of marine DOC. Runoff, slope, soil organic matter and land cover characteristics are the primary spatial factors controlling the variability of fluvial Dissolved Organic Carbon fluxes through the catchment. In large, more heterogeneous catchments, streamflow dissolved organic carbon dynamics are regulated by the combined effect of hydrological mechanisms and the proportion of major landscape elements, such as wetland and forested areas. A number of studies have demonstrated that the amount of wetlands, especially peatlands, controls the watershed level transport of DOC in streams.The Penobscot River Watershed is located in north-central Maine and drains into the Gulf of Maine. It is the second largest watershed in New England. The Penobscot River Watershed is primarily forested but also contains extensive bogs, marshes, and wooded swamps.Studying the spatial and temporal changes in DOC export in the Penobscot River Watershed allows us to better understand and detect carbon sinks to carbon source shifts (or vice versa) in northern forested ecosystems.The Regional Hydro-Ecological Simulation System, is a physical process based terrestrial model that has the ability to simulate both the source and transportation of DOC by combining both hydrological and ecological processes. The study is focused on simulating the DOC concentration and flux with RHESSys in the Penobscot River Watershed. The simulated results are compared with field measurements of DOC from the watershed and the model results from the LOADEST and the temporal DOC export patterns are explored. Future changes in the amount of streamflow DOC will also be investigated by using projected land cover and climate change scenarios. Incremental increases in the loss of wetland areas have been implemented to explore the sensitivity of this watershed to wetland loss and progressive changes in forested land cover

Could combined sleep and pain evaluation be useful in the diagnosis of disorders of consciousness (DOC)? Preliminary findings.

Science.gov (United States)

Aricò, Irene; Naro, Antonino; Pisani, Laura Rosa; Leo, Antonino; Muscarà, Nunzio; De Salvo, Simona; Silvestri, Rosalia; Bramanti, Placido; Calabrò, Rocco Salvatore

2016-01-01

The diagnosis of Disorders of Consciousness (DOC) is still challenging. Indeed, ~ 40% of patients in vegetative state (VS) are misdiagnosed, suggesting the need of more appropriate diagnostic tools. Emerging data are showing that EEG, including sleep structure evaluation and multimodal evoked potential recording could be helpful in DOC diagnosis. Moreover, pain perception evaluation could further increase diagnosis accuracy in such individuals. Fourteen individuals with DOC, due to severe brain injury, were enrolled and admitted to the Intensive Neurorehabilitation Unit of the Research Institute. All patients were evaluated by means of the Coma Recovery Scale-Revised, a 24(hh)-polysomnography and a Laser Evoked Potential (LEP) paradigm. Clinically-defined patients in Minimally Consciousness State showed a more preserved sleep structure, physiologic hypnic figures and preserved REM/NREM sleep distribution than subjects in VS. LEP showed increased latencies and reduced amplitudes and were also detectable in patients with more structured sleep. The data support previous findings concerning the importance of sleep study in DOC diagnosis, with more specific neurophysiological paradigms. Interestingly, the findings shed some light on the possible correlations among global brain connectivity, sleep structure and pain perception, which are related to the activity of the wide thalamo-cortical and cortico-cortical networks underlying consciousness.

Association of ABCB1, β tubulin I, and III with multidrug resistance of MCF7/DOC subline from breast cancer cell line MCF7.

Science.gov (United States)

Li, Wentao; Zhai, Baoping; Zhi, Hui; Li, Yuhong; Jia, Linjiao; Ding, Chao; Zhang, Bin; You, Wei

2014-09-01

Docetaxel is a first-line chemotherapeutic agent for treating advanced breast cancer. The development of chemoresistance or multidrug resistance (MDR), however, results in breast cancer chemotherapy failure. This study aims to explore the molecular mechanisms underlying docetaxel-resistance in treatment of breast cancer. The docetaxel-resistant subline MCF7/DOC, derived from the parental sensitive breast cancer cell line MCF7, was established by intermittent exposure to moderate concentrations of docetaxel, followed by examination of its phenotypes. The MCF7/DOC subline showed cross resistance against paclitaxel, doxorubicin, methotrexate, and 5-Fu. Compared to the parental MCF7, MCF7/DOC cells were enlarged with heterogeneous sizes and a cobblestone and polygonal appearance. They were arrested at G2/M phase and proliferated slowly. The colony formation potential of MCF7/DOC in soft agar was significantly increased. MCF7/DOC cells showed reduced intracellular accumulation and increased efflux of rhodamine 123. The mRNA expression level of adenosine triphosphate binding cassette (ABC) transporter family, i.e., ABCB1, ABCC1, ABCC2, ABCG2, and β tubulin isotypes were characterized by quantitative PCR. High-level expression of ABCB1, βI, and βIII tubulin mRNA in MCF7/DOC was detected. Downregulation of ABCB1, βI, and βIII tubulin mediated by three combined siRNAs resulted in stronger growth inhibition of MCF7/DOC than inhibition of the expression of individual genes. ABCB1, βI, and βIII tubulin might contribute to the MDR of MCF7/DOC and be potential therapeutic targets for overcoming MDR of breast cancer.

Mobilisation and immobilisation of uranium-DOC-species in three waste dumps in the district of Schlema/Alberoda

International Nuclear Information System (INIS)

Kupsch, H.

1998-01-01

The modelling of geochemical processes needs the detailed and comprehensive knowledge of all chemical interactions which are able to exist in the flow path of waste dumps, soils and aquifer. This includes the adsorption, displacement and transport of heavy metal species of fulvic and humic acids which represent the main amount of DOC in the liquid / solid system of flow path. Comparative measurements of DOC concentrations in the input and output flow at the three waste dumps in the district Schlema / Alberoda have indicated that DOC is produced and / or supplied within of waste dumps. The speciation of heavy metal compounds of fulvic and humic acids was realized by means of two methods (sequential chromatographic analysis SCA; ions focussed electrophoresis IFE). Between 5 and 20% of uranium in the flow path exist in the form of fulvic and humic acids species in which the bond of uranium is permanently. Their distribution coefficients are strongly correlated with the pH values of the several geochemical systems. (orig.) [de

Exclusion of brown lemmings reduces vascular plant cover and biomass in Arctic coastal tundra: resampling of a 50 + year herbivore exclosure experiment near Barrow, Alaska

International Nuclear Information System (INIS)

Johnson, D R; Lara, M J; Tweedie, C E; Shaver, G R; Batzli, G O; Shaw, J D

2011-01-01

To determine the role lemmings play in structuring plant communities and their contribution to the 'greening of the Arctic', we measured plant cover and biomass in 50 + year old lemming exclosures and control plots in the coastal tundra near Barrow, Alaska. The response of plant functional types to herbivore exclusion varied among land cover types. In general, the abundance of lichens and bryophytes increased with the exclusion of lemmings, whereas graminoids decreased, although the magnitude of these responses varied among land cover types. These results suggest that sustained lemming activity promotes a higher biomass of vascular plant functional types than would be expected without their presence and highlights the importance of considering herbivory when interpreting patterns of greening in the Arctic. In light of the rapid environmental change ongoing in the Arctic and the potential regional to global implications of this change, further exploration regarding the long-term influence of arvicoline rodents on ecosystem function (e.g. carbon and energy balance) should be considered a research priority.

¹H, ¹³C, and ¹⁵N backbone and side-chain chemical shift assignment of the toxin Doc in the unbound state.

Science.gov (United States)

De Gieter, Steven; Loris, Remy; van Nuland, Nico A J; Garcia-Pino, Abel

2014-04-01

Toxin-antitoxin (TA) modules in bacteria are involved in pathogenesis, antibiotic stress response, persister formation and programmed cell death. The toxin Doc, from the phd/doc module, blocks protein synthesis by targeting the translation machinery. Despite a large wealth of biophysical and biochemical data on the regulatory aspects of the operon transcription and role of Doc co-activator and co-repressor, little is still know on the molecular basis of Doc toxicity. Structural information about this toxin is only available for its inhibited state bound to the antitoxin Phd. Here we report the (1)H, (15)N and (13)C backbone and side chain chemical shift assignments of the toxin Doc from of bacteriophage P1 (the model protein from this family of TA modules) in its free state. The BMRB accession number is 18899.

Vascular Plant and Vertebrate Inventory of Gila Cliff Dwellings National Monument

Science.gov (United States)

Powell, Brian F.; Albrecht, Eric W.; Halvorson, William L.; Schmidt, Cecilia A.; Docherty, Kathleen; Anning, Pamela

2006-01-01

Executive Summary This report summarizes the results of the first comprehensive biological inventory of Gila Cliff Dwellings National Monument (NM) in western New Mexico. This project was part of a larger effort to inventory plants and vertebrates in eight National Park Service units in Arizona and New Mexico. Our surveys address many of the objectives that were set forth in the monument's natural resource management plan almost 20 years ago, but until this effort, those goals were never accomplished. From 2001 to 2003 we surveyed for vascular plants and vertebrates (amphibians, reptiles, birds, and mammals) at Gila Cliff Dwellings NM to document presence of species within the boundaries of the monument. For all taxonomic groups that we studied, we collected 'incidental' sightings on U.S. Forest Service lands adjacent to the monument, and in a few cases we did formal surveys on those lands. Because we used repeatable study designs and standardized field techniques, these inventories can serve as the first step in a biological monitoring program for Gila Cliff Dwellings NM and surrounding lands. We recorded 552 species at Gila Cliff Dwellings NM and the surrounding lands (Table 1). We found no non-native species of reptiles, birds, or mammals, one non-native amphibian (American bullfrog), and 33 non-native plants. Particularly on lands adjacent to the monument we found that the American bullfrog was very abundant, which is a cause for significant management concern. Species of non-native plants that are of management concern include red brome, bufflegrass, and cheatgrass. For a park unit of its size and geographic location, we found the plant and vertebrate communities to be fairly diverse; for each taxonomic group we found representative species from a wide range of taxonomic orders and/or families. The monument's geographic location, with influences from the Rocky Mountain, Chihuahuan Desert, and Madrean ecological provinces, plays an important role in determining

Spatial patterns of DOC concentration and DOM optical properties in a Brazilian tropical river-wetland system

Science.gov (United States)

Dalmagro, Higo J.; Johnson, Mark S.; de Musis, Carlo R.; Lathuillière, Michael J.; Graesser, Jordan; Pinto-Júnior, Osvaldo B.; Couto, Eduardo G.

2017-08-01

The Cerrado (savanna) and Pantanal (wetland) biomes of Central Western Brazil have experienced significant development activity in recent decades, including extensive land cover conversion from natural ecosystems to agriculture and urban expansion. The Cuiabá River transects the Cerrado biome prior to inundating large areas of the Pantanal, creating one of the largest biodiversity hot spots in the world. We measured dissolved organic carbon (DOC) and the optical absorbance and fluorescence properties of dissolved organic matter (DOM) from 40 sampling locations spanning Cerrado and Pantanal biomes during wet and dry seasons. In the upper, more agricultural region of the basin, DOC concentrations were highest in the rainy season with more aromatic and humified DOM. In contrast, DOC concentrations and DOM optical properties were more uniform for the more urbanized middle region of the basin between wet and dry seasons, as well as across sample locations. In the lower region of the basin, wet season connectivity between the river and the Pantanal floodplain led to high DOC concentrations, a fourfold increase in humification index (HIX) (an indicator of DOM humification), and a 50% reduction in the spectral slope (SR). Basin-wide, wet season values for SR, HIX, and FI (fluorescence index) indicated an increasing representation of terrestrially derived DOM that was more humified. Parallel factor analysis identified two terrestrially derived components (C1 and C2) representing 77% of total fluorescing DOM (fDOM). A third, protein-like fDOM component increased markedly during the wet season within the more urban-impacted region.

CDOM fluorescence as a proxy of DOC concentration in natural waters : a comparison of four contrasting tropical systems

OpenAIRE

Rochelle Newall, Emma; Hulot, F. D.; Janeau, Jean-Louis; Merroune, A.

2014-01-01

Chromophoric dissolved organic matter (CDOM) fluorescence or absorption is often proposed as a rapid alternative to chemical methods for the estimation of bulk dissolved organic carbon (DOC) concentration in natural waters. However, the robustness of this method across a wide range of systems remains to be shown. We measured CDOM fluorescence and DOC concentration in four tropical freshwater and coastal environments (estuary and coastal, tropical shallow lakes, water from the freshwater lens ...

Phytogeography of the vascular páramo flora of Podocarpus National Park, south Ecuador

NARCIS (Netherlands)

Lozano, P.; Cleef, A.M.; Bussmann, R.W.

2009-01-01

A plant ecological transect study of the páramos of the Podocarpus massif, southern Ecuador, was carried out between July 2001 and August 2004. Including herbarium records 187 vascular plant genera were found, which were used for the present phytogeographical analysis. Three geographic flora

Delivery of adjuvant sequential dose-dense FEC-Doc to patients with breast cancer is feasible, but dose reductions and toxicity are dependent on treatment sequence.

Science.gov (United States)

Wildiers, H; Dirix, L; Neven, P; Prové, A; Clement, P; Squifflet, P; Amant, F; Skacel, T; Paridaens, R

2009-03-01

This study prospectively investigates the impact of dose densification and altering sequence of fluorouracil, epirubicin and cyclophosphamide [FEC(100)] and docetaxel [Doc] on dose delivery and tolerability of adjuvant chemotherapy in breast cancer patients. 117 patients with high-risk primary operable breast cancer were randomized (1:1:2:2) to conventional (three cycles of 3-weekly FEC(100) then three cycles of 3-weekly Doc 100 mg/m(2) or reverse sequence) or dose-dense (dd) treatment (four 10- to 11-day cycles of FEC(75) then four 2-weekly cycles of Doc 75 mg/m(2), or the reverse). In the dd arms, pegfilgrastim was given on day 2 of each cycle, but only as secondary prophylaxis in conventional arms. The primary endpoint was the proportion of patients completing intended cycles at relative dose intensity >or=85% and this was achieved by 95% of patients in each group except for the ddDoc-->FEC group (90%). Dose intensity in the dd arms increased by 48% for FEC and 11% for docetaxel, compared with the conventional arms (both P Doc dose reductions were more frequent with dd treatment and when Doc was given after FEC. Grade 3-4 neutropenia was significantly more frequent with conventional treatment, while fatigue and hand-foot syndrome were numerically more common with dd treatment, particularly when Doc was given after FEC. Discussion Delivery of adjuvant sequential ddFEC and Doc is feasible with growth factor support, and chemotherapy sequence appeared to affect delivery of target doses and toxicity.

A comprehensive checklist of vascular epiphytes of the Atlantic Forest reveals outstanding endemic rates.

Science.gov (United States)

Freitas, Leandro; Salino, Alexandre; Neto, Luiz Menini; Elias Almeida, Thaís; Mortara, Sara Ribeiro; Stehmann, João Renato; Amorim, André Marcio; Guimarães, Elsie Franklin; Coelho, Marcus Nadruz; Zanin, Ana; Forzza, Rafaela Campostrini

2016-01-01

Knowledge of the geographic distribution of plants is essential to underpin the understanding of global biodiversity patterns. Vascular epiphytes are important components of diversity and functionality of Neotropical forests but, unlike their terrestrial counterparts, they are under-represented in large-scale diversity and biogeographic analyses. This is the case for the Atlantic Forest - one of the most diverse and threatened biomes worldwide. We provide the first comprehensive species list of Atlantic Forest vascular epiphytes; their endemism patterns and threatened species occurrence have also been analyzed. A list with 2,256 species of (hemi-)epiphytes - distributed in 240 genera and 33 families - is presented based on the updated Brazilian Flora Checklist. This represents more than 15% of the total vascular plant richness in the Atlantic Forest. Moreover, 256 species are included on the Brazilian Red List. More than 93% of the overall richness is concentrated in ten families, with 73% represented by Orchidaceae and Bromeliaceae species alone. A total of 78% of epiphytic species are endemic to the Atlantic Forest, in contrast to overall vascular plant endemism in this biome estimated at 57%. Among the non-endemics, 13% of epiphytic species also occur either in the Amazon or in the Cerrado - the other two largest biomes of Brazil - and only 8% are found in two or more Brazilian biomes. This pattern of endemism, in addition to available dated phylogenies of some genera, indicate the dominance of recent radiations of epiphytic groups in the Atlantic Forest, showing that the majority of divergences dating from the Pliocene onwards are similar to those that were recently reported for other Neotropical plants.

Flora of vascular plants of selected Poznań cemeteries

Directory of Open Access Journals (Sweden)

Aneta Czarna

2012-12-01

Full Text Available The presence of 395 species of vascular flora at four rarely used cemeteries within the Poznań city was confirmed in 2010. Apart from naturally occurring species, cultivated species were noted equally. Among species appearing spontaneously between the graves, species new for the flora of Poland: Chionodoxa forbesii, Ch. luciliae, Puschkinia scilloides, new for the flora of Wielkopolska: Bidens ferulifolius, Hyacinthoides hispanica and new for the flora of Poznań: Erigeron ramosus, Lilium bulbiferum, Pimpinella nigra, Poa subcaerulea, Veronica hederifolia s.s., were recorded. Names of taxa originating from cultivation are underlined.

76 FR 55137 - Monitoring the Effectiveness of Maintenance at Nuclear Power Plants