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  1. Biomes.

    Science.gov (United States)

    Web Feet K-8, 2001

    2001-01-01

    This annotated subject guide to Web sites and additional resources focuses on biomes. Specifies age levels for resources that include Web sites, CD-ROMs and software, videos, books, audios, and magazines; includes professional resources; and presents a relevant class activity. (LRW)

  2. Toward Understanding Dynamics in Shifting Biomes: An Individual Based Modeling Approach to Characterizing Drought and Mortality in Central Western Canada

    Science.gov (United States)

    Armstrong, A. H.; Foster, A.; Rogers, B. M.; Hogg, T.; Michaelian, M.; Shuman, J. K.; Shugart, H. H., Jr.; Goetz, S. J.

    2017-12-01

    The Arctic-Boreal zone is known be warming at an accelerated rate relative to other biomes. Persistent warming has already affected the high northern latitudes, altering vegetation productivity, carbon sequestration, and many other ecosystem processes and services. The central-western Canadian boreal forests and aspen parkland are experiencing a decade long drought, and rainfall has been identified as a key factor controlling the location of the boundary between forest and prairie in this region. Shifting biome with related greening and browning trends are readily measureable with remote sensing, but the dynamics that create and result from them are not well understood. In this study, we use the University of Virginia Forest Model Enhanced (UVAFME), an individual-based forest model, to simulate the changes that are occurring across the southern boreal and parkland forests of west-central Canada. We present a parameterization of UVAFME for western central Canadian forests, validated with CIPHA data (Climate Change Impacts on the Productivity and Health of Aspen), and improved mortality. In order to gain a fine-scale understanding of how climate change and specifically drought will continue to affect the forests of this region, we simulated forest conditions following CMIP5 climate scenarios. UVAFME predictions were compared with statistical models and satellite observations of productivity across the landscape. Changes in forest cover, forest type, aboveground biomass, and mortality and recruitment dynamics are presented, highlighting the high vulnerability of this region to vegetation transitions associated with future droughts.

  3. Aquatic ecosystem responses to Holocene climate change and biome development in boreal, central Asia

    Science.gov (United States)

    Mackay, Anson W.; Bezrukova, Elena V.; Leng, Melanie J.; Meaney, Miriam; Nunes, Ana; Piotrowska, Natalia; Self, Angela; Shchetnikov, Alexander; Shilland, Ewan; Tarasov, Pavel; Wang, Luo; White, Dustin

    2012-05-01

    Boreal ecosystems are highly vulnerable to climate change, and severe ecological impacts in the near future are virtually certain to occur. We undertook a multiproxy study on an alpine lake (ESM-1) at the modern tree-line in boreal, southern Siberia. Steppe and tundra biomes were extensive in eastern Sayan landscapes during the early Holocene. Boreal forest quickly expanded by 9.1 ka BP, and dominated the landscape until c 0.7 ka BP, when the greatest period of compositional turnover occurred. At this time, alpine meadow landscape expanded and Picea obovata colonised new habitats along river valleys and lake shorelines, because of prevailing cool, moist conditions. During the early Holocene, chironomid assemblages were dominated by cold stenotherms. Diatoms for much of the Holocene were dominated by alkaliphilous, fragilarioid taxa, up until 0.2 ka BP, when epiphytic species expanded, indicative of increased habitat availability. C/N mass ratios ranged between 9.5 and 13.5 (11.1-15.8 C/N atomic ratios), indicative of algal communities dominating organic matter contributions to bottom sediments with small, persistent contributions from vascular plants. However, δ13C values increased steadily from -34.9‰ during the early Holocene (9.3 ka BP) to -24.8‰ by 0.6 ka BP. This large shift in magnitude may be due to a number of factors, including increasing within-lake productivity, increasing disequilibrium between the isotopic balance of the lake with the atmosphere as the lake became isotopically ‘mature’, and declining soil respiration linked to small, but distinct retreat in forest biomes. The influence of climatic variables on landscape vegetation was assessed using redundancy analysis (RDA), a linear, direct ordination technique. Changes in July insolation at 60 °N significantly explained over one-fifth of the variation in species composition, while changes in estimates of northern hemisphere temperature and ice-rafted debris events in the North Atlantic

  4. User's Guide to Biome Information from the United States International Biological Program (IBP). First Edition.

    Science.gov (United States)

    Hinckley, A. Dexter; Haug, Peter T.

    This publication is a guide to the biome research conducted under the International Biological Program. The guide lists biome researchers by interest and by biome as well as a central list. A site list, map, information sources section reporting abstracts, bibliographies, journals, books, evaluations, and data books are also included. Three…

  5. Consequences of biome depletion

    International Nuclear Information System (INIS)

    Salvucci, Emiliano

    2013-01-01

    The human microbiome is an integral part of the superorganism together with their host and they have co-evolved since the early days of the existence of the human species. The modification of the microbiome as a result changes in food and social habits of human beings throughout their life history has led to the emergence of many diseases. In contrast with the Darwinian view of nature of selfishness and competence, new holistic approaches are rising. Under these views, the reconstitution of the microbiome comes out as a fundamental therapy for emerging diseases related to biome depletion.

  6. MedlinePlus

    Data.gov (United States)

    U.S. Department of Health & Human Services — MedlinePlus is the National Institutes of Health's Web site for patients and their families and friends. Produced by the National Library of Medicine, the world’s...

  7. MedlinePlus Tour

    Science.gov (United States)

    ... captioning, click the CC button on the lower right-hand corner of the player. Video player keyboard shortcuts Transcript Welcome to MedlinePlus, the consumer health information website from the National Library of ...

  8. Disturbance maintains alternative biome states.

    Science.gov (United States)

    Dantas, Vinícius de L; Hirota, Marina; Oliveira, Rafael S; Pausas, Juli G

    2016-01-01

    Understanding the mechanisms controlling the distribution of biomes remains a challenge. Although tropical biome distribution has traditionally been explained by climate and soil, contrasting vegetation types often occur as mosaics with sharp boundaries under very similar environmental conditions. While evidence suggests that these biomes are alternative states, empirical broad-scale support to this hypothesis is still lacking. Using community-level field data and a novel resource-niche overlap approach, we show that, for a wide range of environmental conditions, fire feedbacks maintain savannas and forests as alternative biome states in both the Neotropics and the Afrotropics. In addition, wooded grasslands and savannas occurred as alternative grassy states in the Afrotropics, depending on the relative importance of fire and herbivory feedbacks. These results are consistent with landscape scale evidence and suggest that disturbance is a general factor driving and maintaining alternative biome states and vegetation mosaics in the tropics. © 2015 John Wiley & Sons Ltd/CNRS.

  9. Evolution of the indoor biome.

    Science.gov (United States)

    Martin, Laura J; Adams, Rachel I; Bateman, Ashley; Bik, Holly M; Hawks, John; Hird, Sarah M; Hughes, David; Kembel, Steven W; Kinney, Kerry; Kolokotronis, Sergios-Orestis; Levy, Gabriel; McClain, Craig; Meadow, James F; Medina, Raul F; Mhuireach, Gwynne; Moreau, Corrie S; Munshi-South, Jason; Nichols, Lauren M; Palmer, Clare; Popova, Laura; Schal, Coby; Täubel, Martin; Trautwein, Michelle; Ugalde, Juan A; Dunn, Robert R

    2015-04-01

    Few biologists have studied the evolutionary processes at work in indoor environments. Yet indoor environments comprise approximately 0.5% of ice-free land area--an area as large as the subtropical coniferous forest biome. Here we review the emerging subfield of 'indoor biome' studies. After defining the indoor biome and tracing its deep history, we discuss some of its evolutionary dimensions. We restrict our examples to the species found in human houses--a subset of the environments constituting the indoor biome--and offer preliminary hypotheses to advance the study of indoor evolution. Studies of the indoor biome are situated at the intersection of evolutionary ecology, anthropology, architecture, and human ecology and are well suited for citizen science projects, public outreach, and large-scale international collaborations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Biomes computed from simulated climatologies

    Energy Technology Data Exchange (ETDEWEB)

    Claussen, M.; Esch, M. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

    1994-01-01

    The biome model of Prentice et al. is used to predict global patterns of potential natural plant formations, or biomes, from climatologies simulated by ECHAM, a model used for climate simulations at the Max-Planck-Institut fuer Meteorologie. This study undertaken in order to show the advantage of this biome model in diagnosing the performance of a climate model and assessing effects of past and future climate changes predicted by a climate model. Good overall agreement is found between global patterns of biomes computed from observed and simulated data of present climate. But there are also major discrepancies indicated by a difference in biomes in Australia, in the Kalahari Desert, and in the Middle West of North America. These discrepancies can be traced back to in simulated rainfall as well as summer or winter temperatures. Global patterns of biomes computed from an ice age simulation reveal that North America, Europe, and Siberia should have been covered largely by tundra and taiga, whereas only small differences are for the tropical rain forests. A potential northeast shift of biomes is expected from a simulation with enhanced CO{sub 2} concentration according to the IPCC Scenario A. Little change is seen in the tropical rain forest and the Sahara. Since the biome model used is not capable of predicting chances in vegetation patterns due to a rapid climate change, the latter simulation to be taken as a prediction of chances in conditions favourable for the existence of certain biomes, not as a reduction of a future distribution of biomes. 15 refs., 8 figs., 2 tabs.

  11. Biomes computed from simulated climatologies

    Energy Technology Data Exchange (ETDEWEB)

    Claussen, W.; Esch, M.

    1992-09-01

    The biome model of Prentice et al. is used to predict global patterns of potential natural plant formations, or biomes, from climatologies simulated by ECHAM, a model used for climate simulations at the Max-Planck-Institut fuer Meteorologie. This study is undertaken in order to show the advantage of this biome model in comprehensively diagnosing the performance of a climate model and assessing effects of past and future climate changes predicted by a climate model. Good overall agreement is found between global patterns of biomes computed from observed and simulated data of present climate. But there are also major discrepancies indicated by a difference in biomes in Australia, in the Kalahari Desert, and in the Middle West of North America. These discrepancies can be traced back to failures in simulated rain fall as well as summer or winter temperatures. Global patterns of biomes computed from an ice age simulation reveal that North America, Europe, and Siberia should have been covered largely by tundra and taiga, whereas only small differences are seen for the tropical rain forests. A potential North-East shift of biomes is expected from a simulation with enhanced CO{sub 2} concentration according to the IPCC Scenario A. Little change is seen in the tropical rain forest and the Sahara. Since the biome model used is not capable of predicting changes in vegetation patterns due to a rapid climate change, the latter simulation has to be taken as a prediction of changes in conditions favorable for the existence of certain biomes, not as a prediction of a future distribution of biomes. (orig.).

  12. MedlinePlus FAQ: MedlinePlus and MEDLINE/PubMed

    Science.gov (United States)

    ... What is the difference between MedlinePlus and MEDLINE/PubMed? To use the sharing features on this page, ... latest health professional articles on your topic. MEDLINE/PubMed: Is a database of professional biomedical literature Is ...

  13. Linking to MedlinePlus

    Science.gov (United States)

    ... want to link patients or healthcare providers from electronic health record (EHR) systems to relevant MedlinePlus information, use MedlinePlus ... updates Subscribe to RSS Follow us Disclaimers Copyright Privacy Accessibility Quality Guidelines Viewers & Players MedlinePlus Connect for ...

  14. Articles about MedlinePlus

    Science.gov (United States)

    ... MedlinePlus → Articles about MedlinePlus URL of this page: https://medlineplus.gov/bibliography.html Articles about MedlinePlus To ... Dec 29]; 3(5):256-60. Available from: http://ecp.acponline.org/sepoct00/nlm.htm . Marill JL, ...

  15. Description of the Karoo Biome project

    CSIR Research Space (South Africa)

    Cowling, RM

    1986-01-01

    Full Text Available The ecological characteristics and ecological problems of the karoo biome are briefly described. A conceptual basis and guidelines for the development of the Karoo Biome Project are outlined by addressing project goals, project structure...

  16. Description of the Grassland Biome Project

    CSIR Research Space (South Africa)

    Mentis, MT

    1982-10-01

    Full Text Available The objectives, organization and research programme of the Grassland Biome Project are described against a background of the biome's ecological characteristics and environmental problems. Four principal research topics wil 1 be focused upon: (i...

  17. MedlinePlus FAQ: What's the difference between MedlinePlus and MedlinePlus Connect?

    Science.gov (United States)

    ... MedlinePlus Connect is a free service that allows electronic health record (EHR) systems to easily link users to MedlinePlus, ... updates Subscribe to RSS Follow us Disclaimers Copyright Privacy Accessibility Quality Guidelines Viewers & Players MedlinePlus Connect for ...

  18. The Medline/full-text research project.

    Science.gov (United States)

    McKinin, E J; Sievert, M; Johnson, E D; Mitchell, J A

    1991-05-01

    This project was designed to test the relative efficacy of index terms and full-text for the retrieval of documents in those MEDLINE journals for which full-text searching was also available. The full-text files used were MEDIS from Mead Data Central and CCML from BRS Information Technologies. One hundred clinical medical topics were searched in these two files as well as the MEDLINE file to accumulate the necessary data. It was found that full-text identified significantly more relevant articles than did the indexed file, MEDLINE. The full-text searches, however, lacked the precision of searches done in the indexed file. Most relevant items missed in the full-text files, but identified in MEDLINE, were missed because the searcher failed to account for some aspect of natural language, used a logical or positional operator that was too restrictive, or included a concept which was implied, but not expressed in the natural language. Very few of the unique relevant full-text citations would have been retrieved by title or abstract alone. Finally, as of July, 1990 the more current issue of a journal was just as likely to appear in MEDLINE as in one of the full-text files.

  19. Biosphere 2's Marsh Biome

    Science.gov (United States)

    Molnar, Jennifer; Goodridge, Kelven

    1997-01-01

    The Marsh Biome, which was modeled after the mangroves and marshes of southwest Florida, has an area of 441.2 sq m separated into three hydrologically independent sections: the Freshwater, Oligohaline and Salt Marshes. The divisions are made based on their salinity (approximately 0, 4, and 34 ppt. respectively), but they also contain different biological communities. The Freshwater and Oligohaline Marshes are mostly filled with various grasses and several trees, while the Salt Marsh houses regions of red, black, and white mangroves (Rhizophora mangle, Avicennia germinans, and Languncularia racemosa respectively). Overall, there are an estimated 80 species of plants within the biome. Water in the Salt Marsh follows a meandering stream from the algal turf scrubbers (apparatuses that clean the water of its nutrients and heavy metals while increasing dissolved oxygen levels) which have an outlet in the Salt Marsh section near sites 4 and 5 to the Fringing Red Mangrove section. The sections of the Salt Marsh are separated by walls of concrete with openings to allow the stream to flow through. Throughout this study, conducted through the months of June and July, many conditions within the biome remained fairly constant. The temperature was within a degree or two of 25 C, mostly depending on whether the sample site was in direct sunlight or shaded. The pH throughout the Salt Marsh was 8.0 +/- 0.2, and the lower salinity waters only dropped below this soon after rains. The water rdepth and dissolved oxygen varied, however, between sites.

  20. Mobile MedlinePlus | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... version of this page please turn Javascript on. Mobile MedlinePlus Past Issues / Spring 2013 Table of Contents Trusted medical information on your mobile phone http://m.medlineplus.gov Wondering what the ...

  1. Mobile MedlinePlus | NIH MedlinePlus Magazine

    Science.gov (United States)

    ... version of this page please turn Javascript on. Mobile MedlinePlus Past Issues / Winter 2010 Table of Contents Trusted medical information on your mobile phone http://m.medlineplus.gov Wondering what the ...

  2. Search Tips: MedlinePlus

    Science.gov (United States)

    ... of this page: https://medlineplus.gov/searchtips.html Search Tips To use the sharing features on this page, please enable JavaScript. How do I search MedlinePlus? The search box appears at the top ...

  3. MedlinePlus FAQ: Framing

    Science.gov (United States)

    ... URL of this page: https://medlineplus.gov/faq/framing.html I'd like to link to MedlinePlus, ... M. encyclopedia. Our license agreements do not permit framing of their content from our site. For more ...

  4. Health Videos: MedlinePlus

    Science.gov (United States)

    ... Duplication for commercial use must be authorized in writing by ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow us Disclaimers Copyright ...

  5. Medical Encyclopedia: MedlinePlus

    Science.gov (United States)

    ... Duplication for commercial use must be authorized in writing by ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow us Disclaimers Copyright ...

  6. Phylogenetic biome conservatism on a global scale.

    Science.gov (United States)

    Crisp, Michael D; Arroyo, Mary T K; Cook, Lyn G; Gandolfo, Maria A; Jordan, Gregory J; McGlone, Matt S; Weston, Peter H; Westoby, Mark; Wilf, Peter; Linder, H Peter

    2009-04-09

    How and why organisms are distributed as they are has long intrigued evolutionary biologists. The tendency for species to retain their ancestral ecology has been demonstrated in distributions on local and regional scales, but the extent of ecological conservatism over tens of millions of years and across continents has not been assessed. Here we show that biome stasis at speciation has outweighed biome shifts by a ratio of more than 25:1, by inferring ancestral biomes for an ecologically diverse sample of more than 11,000 plant species from around the Southern Hemisphere. Stasis was also prevalent in transocean colonizations. Availability of a suitable biome could have substantially influenced which lineages establish on more than one landmass, in addition to the influence of the rarity of the dispersal events themselves. Conversely, the taxonomic composition of biomes has probably been strongly influenced by the rarity of species' transitions between biomes. This study has implications for the future because if clades have inherently limited capacity to shift biomes, then their evolutionary potential could be strongly compromised by biome contraction as climate changes.

  7. Shift of biome patterns due to simulated climate variability and climate change

    International Nuclear Information System (INIS)

    Claussen, M.

    1993-01-01

    The variability of simulated equilibrium-response patterns of biomes caused by simulated climate variability and climate shift is analysed. This investigation is based on various realisations of simulated present-day climate and climate shift. It has been found that the difference between biomes computed from three 10-year climatologies and from the corresponding 30-year climatology, simulated by the Hamburg climate model at T21 resolution, amounts to approximately 6% of the total land area, Antarctica excluded. This difference is mainly due to differences in annual moisture availability and winter temperatures. When intercomparing biomes from the 10-year climatologies a 10% difference is seen, but there is no unique difference pattern. In contrast to the interdecadal variability, the shift of conditions favorable for biomes due to a shift in climate in the next 100 years, caused by an increase in sea-surface temperatures and atmospheric CO 2 , reveals a unique trend pattern. It turns out that the strongest and most significant signal is the north-east shift of conditions for boreal biomes. This signal is caused by an increase of annual temperature sums as well as mean temperatures of the coldest and warmest months. Trends in annual moisture availability are of secondary importance globally. Regionally, a decrease in water availability affects biomes in Central and East Europe and an increase of water availability leads to a potential increase in tropical rain forest. In total, all differences amount to roughly 30% of the total land surface, Antarctica excluded. (orig./KW)

  8. Description of the Fynbos Biome Project

    CSIR Research Space (South Africa)

    Kruger, FJ

    1978-06-01

    Full Text Available The objectives, organization and research programme of the Fynbos Biome Project being undertaken in the south-west and southern Cape are described. The project is a cooperative multi-disciplinary study of the ecological characteristics, structure...

  9. Thresholds for boreal biome transitions.

    Science.gov (United States)

    Scheffer, Marten; Hirota, Marina; Holmgren, Milena; Van Nes, Egbert H; Chapin, F Stuart

    2012-12-26

    Although the boreal region is warming twice as fast as the global average, the way in which the vast boreal forests and tundras may respond is poorly understood. Using satellite data, we reveal marked alternative modes in the frequency distributions of boreal tree cover. At the northern end and at the dry continental southern extremes, treeless tundra and steppe, respectively, are the only possible states. However, over a broad intermediate temperature range, these treeless states coexist with boreal forest (∼75% tree cover) and with two more open woodland states (∼20% and ∼45% tree cover). Intermediate tree covers (e.g., ∼10%, ∼30%, and ∼60% tree cover) between these distinct states are relatively rare, suggesting that they may represent unstable states where the system dwells only transiently. Mechanisms for such instabilities remain to be unraveled, but our results have important implications for the anticipated response of these ecosystems to climatic change. The data reveal that boreal forest shows no gradual decline in tree cover toward its limits. Instead, our analysis suggests that it becomes less resilient in the sense that it may more easily shift into a sparse woodland or treeless state. Similarly, the relative scarcity of the intermediate ∼10% tree cover suggests that tundra may shift relatively abruptly to a more abundant tree cover. If our inferences are correct, climate change may invoke massive nonlinear shifts in boreal biomes.

  10. The extent of forest in dryland biomes

    Science.gov (United States)

    Jean-Francois Bastin; Nora Berrahmouni; Alan Grainger; Danae Maniatis; Danilo Mollicone; Rebecca Moore; Chiara Patriarca; Nicolas Picard; Ben Sparrow; Elena Maria Abraham; Kamel Aloui; Ayhan Atesoglu; Fabio Attore; Caglar Bassullu; Adia Bey; Monica Garzuglia; Luis G. GarcÌa-Montero; Nikee Groot; Greg Guerin; Lars Laestadius; Andrew J. Lowe; Bako Mamane; Giulio Marchi; Paul Patterson; Marcelo Rezende; Stefano Ricci; Ignacio Salcedo; Alfonso Sanchez-Paus Diaz; Fred Stolle; Venera Surappaeva; Rene Castro

    2017-01-01

    Dryland biomes cover two-fifths of Earth’s land surface, but their forest area is poorly known. Here, we report an estimate of global forest extent in dryland biomes, based on analyzing more than 210,000 0.5-hectare sample plots through a photo-interpretation approach using large databases of satellite imagery at (i) very high spatial resolution and (ii) very high...

  11. Beyond MEDLINE for literature searches.

    Science.gov (United States)

    Conn, Vicki S; Isaramalai, Sang-arun; Rath, Sabyasachi; Jantarakupt, Peeranuch; Wadhawan, Rohini; Dash, Yashodhara

    2003-01-01

    To describe strategies for a comprehensive literature search. MEDLINE searches result in limited numbers of studies that are often biased toward statistically significant findings. Diversified search strategies are needed. Empirical evidence about the recall and precision of diverse search strategies is presented. Challenges and strengths of each search strategy are identified. Search strategies vary in recall and precision. Often sensitivity and specificity are inversely related. Valuable search strategies include examination of multiple diverse computerized databases, ancestry searches, citation index searches, examination of research registries, journal hand searching, contact with the "invisible college," examination of abstracts, Internet searches, and contact with sources of synthesized information. Extending searches beyond MEDLINE enables researchers to conduct more systematic comprehensive searches.

  12. Himalayan uplift shaped biomes in Miocene temperate Asia: evidence from leguminous Caragana

    Science.gov (United States)

    Ming-Li Zhang; Xiao-Guo Xiang; Juan-Juan Xue; Stewart C. Sanderson; Peter W. Fritsch

    2016-01-01

    Caragana, with distinctive variation in leaf and rachis characters, exhibits three centers of geographic distribution, i.e., Central Asia, the Qinghai-Tibetan Plateau (QTP), and East Asia, corresponding to distinct biomes. Because Caragana species are often ecologically dominant components of the vegetation in these regions, it is regarded as a key taxon for...

  13. MedlinePlus Milestones: 1998-present

    Science.gov (United States)

    ... Connect , a service linking patients or providers in electronic health record (EHR) systems to related MedlinePlus information on conditions ... updates Subscribe to RSS Follow us Disclaimers Copyright Privacy Accessibility Quality Guidelines Viewers & Players MedlinePlus Connect for ...

  14. MedlinePlus Connect in Use

    Science.gov (United States)

    ... MedlinePlus Connect in Use URL of this page: https://medlineplus.gov/connect/users.html MedlinePlus Connect in ... will change.) Old URLs New URLs Web Application https://apps.nlm.nih.gov/medlineplus/services/mpconnect.cfm? ...

  15. Dry Mouth: MedlinePlus Health Topic

    Science.gov (United States)

    ... MEDLINE/PubMed (National Library of Medicine) Article: Transcription profiling of peripheral B cells in antibody-positive primary ... our quality guidelines . About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  16. MedlinePlus XML Data Sources

    Science.gov (United States)

    ... on MedlinePlus health topic pages. With the Web service, software developers can build applications that leverage the authoritative, reliable health information in MedlinePlus. The MedlinePlus Web service is free of charge and does not require ...

  17. Changes in forest productivity across Alaska consistent with biome shift

    Science.gov (United States)

    Peter S.A. Beck; Glenn P. Juday; Claire Alix; Valerie A. Barber; Stephen E. Winslow; Emily E. Sousa; Patricia Heiser; James D. Herriges; Scott J. Goetz

    2011-01-01

    Global vegetation models predict that boreal forests are particularly sensitive to a biome shift during the 21st century. This shift would manifest itself first at the biome's margins, with evergreen forest expanding into current tundra while being replaced by grasslands or temperate forest at the biome's southern edge. We evaluated changes in forest...

  18. On coupling global biome models with climate models

    International Nuclear Information System (INIS)

    Claussen, M.

    1994-01-01

    The BIOME model of Prentice et al. (1992), which predicts global vegetation patterns in equilibrium with climate, is coupled with the ECHAM climate model of the Max-Planck-Institut fuer Meteorologie, Hamburg. It is found that incorporation of the BIOME model into ECHAM, regardless at which frequency, does not enhance the simulated climate variability, expressed in terms of differences between global vegetation patterns. Strongest changes are seen only between the initial biome distribution and the biome distribution computed after the first simulation period, provided that the climate-biome model is started from a biome distribution that resembles the present-day distribution. After the first simulation period, there is no significant shrinking, expanding, or shifting of biomes. Likewise, no trend is seen in global averages of land-surface parameters and climate variables. (orig.)

  19. Biogeography of photoautotrophs in the high polar biome

    Directory of Open Access Journals (Sweden)

    Stephen Brian Pointing

    2015-09-01

    Full Text Available The global latitudinal gradient in biodiversity weakens in the high polar biome and so an alternative explanation for distribution of Arctic and Antarctic photoautotrophs is required. Here we identify how temporal, microclimate and evolutionary drivers of biogeography are important, rather than the macroclimate features that drive plant diversity patterns elsewhere. High polar ecosystems are biologically unique, with a more central role for bryophytes, lichens and microbial photoautotrophs over that of vascular plants. Constraints on vascular plants arise mainly due to stature and ontogenetic barriers. Conversely non-vascular plant and microbial photoautotroph distribution is correlated with favourable microclimates and the capacity for poikilohydric dormancy. Contemporary distribution also depends on evolutionary history, with adaptive and dispersal traits as well as legacy influencing biogeography. We highlight the relevance of these findings to predicting future impacts on polar plant diversity and to the current status of plants in Arctic and Antarctic conservation policy frameworks.

  20. Biome Is Where the Art Is

    Science.gov (United States)

    Gooden, Kelly

    2005-01-01

    The author is surprised every year when fifth-grade students react to the study of biomes as if they've never given any thought to the differences across parts of the world. Sure, they've all heard of the tropical rain forest and the desert, but it seems as though they think the rest of the world is just some undefined area with climate, animals,…

  1. The Brazilian Pampa: A Fragile Biome

    Directory of Open Access Journals (Sweden)

    Valdir Marcos Stefenon

    2009-12-01

    Full Text Available Biodiversity is one of the most fundamental properties of Nature. It underpins the stability of ecosystems, provides vast bioresources for economic use, and has important cultural significance for many people. The Pampa biome, located in the southernmost state of Brazil, Rio Grande do Sul, illustrates the direct and indirect interdependence of humans and biodiversity. The Brazilian Pampa lies within the South Temperate Zone where grasslands scattered with shrubs and trees are the dominant vegetation. The soil, originating from sedimentary rocks, often has an extremely sandy texture that makes them fragile—highly prone to water and wind erosion. Human activities have converted or degraded many areas of this biome. In this review we discuss our state-of-the-art knowledge of the diversity and the major biological features of this regions and the cultural factors that have shaped it. Our aim is to contribute toward a better understanding of the current status of this special biome and to describe how the interaction between human activities and environment affects the region, highlighting the fragility of the Brazilian Pampa.

  2. MedlinePlus Connect: Web Service

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  3. MedlinePlus Connect: Web Application

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  4. MedlinePlus Connect: Technical Information

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  5. MedlinePlus Connect: Email List

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  6. MedlinePlus.gov on Twitter

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    ... page please turn Javascript on. MedlinePlus.gov on Twitter Past Issues / Fall 2009 Table of Contents You can now follow MedlinePlus.gov on Twitter: twitter.com/medlineplus4you The medlineplus4you Twitter feed provides ...

  7. Finding biomedical categories in Medline®

    Directory of Open Access Journals (Sweden)

    Yeganova Lana

    2012-10-01

    Full Text Available Abstract Background There are several humanly defined ontologies relevant to Medline. However, Medline is a fast growing collection of biomedical documents which creates difficulties in updating and expanding these humanly defined ontologies. Automatically identifying meaningful categories of entities in a large text corpus is useful for information extraction, construction of machine learning features, and development of semantic representations. In this paper we describe and compare two methods for automatically learning meaningful biomedical categories in Medline. The first approach is a simple statistical method that uses part-of-speech and frequency information to extract a list of frequent nouns from Medline. The second method implements an alignment-based technique to learn frequent generic patterns that indicate a hyponymy/hypernymy relationship between a pair of noun phrases. We then apply these patterns to Medline to collect frequent hypernyms as potential biomedical categories. Results We study and compare these two alternative sets of terms to identify semantic categories in Medline. We find that both approaches produce reasonable terms as potential categories. We also find that there is a significant agreement between the two sets of terms. The overlap between the two methods improves our confidence regarding categories predicted by these independent methods. Conclusions This study is an initial attempt to extract categories that are discussed in Medline. Rather than imposing external ontologies on Medline, our methods allow categories to emerge from the text.

  8. Automatic inference of indexing rules for MEDLINE

    Directory of Open Access Journals (Sweden)

    Shooshan Sonya E

    2008-11-01

    Full Text Available Abstract Background: Indexing is a crucial step in any information retrieval system. In MEDLINE, a widely used database of the biomedical literature, the indexing process involves the selection of Medical Subject Headings in order to describe the subject matter of articles. The need for automatic tools to assist MEDLINE indexers in this task is growing with the increasing number of publications being added to MEDLINE. Methods: In this paper, we describe the use and the customization of Inductive Logic Programming (ILP to infer indexing rules that may be used to produce automatic indexing recommendations for MEDLINE indexers. Results: Our results show that this original ILP-based approach outperforms manual rules when they exist. In addition, the use of ILP rules also improves the overall performance of the Medical Text Indexer (MTI, a system producing automatic indexing recommendations for MEDLINE. Conclusion: We expect the sets of ILP rules obtained in this experiment to be integrated into MTI.

  9. NIH Institutes and MLN MedlinePlus Advisory Board | NIH MedlinePlus the Magazine

    Science.gov (United States)

    Skip to main content NIH MedlinePlus the Magazine NIH MedlinePlus Salud Download the Current Issue PDF [3.1 mb] Trusted Health Information from the National Institutes of Health Home Current Issue ...

  10. Anthropogenic Biomes of the World, Version 2: 1700

    Data.gov (United States)

    National Aeronautics and Space Administration — The Anthropogenic Biomes of the World, Version 2: 1700 data set describes anthropogenic transformations within the terrestrial biosphere caused by sustained direct...

  11. Anthropogenic Biomes of the World, Version 2: 1900

    Data.gov (United States)

    National Aeronautics and Space Administration — The Anthropogenic Biomes of the World, Version 2: 1900 data set describes anthropogenic transformations within the terrestrial biosphere caused by sustained direct...

  12. Anthropogenic Biomes of the World, Version 2: 1800

    Data.gov (United States)

    National Aeronautics and Space Administration — The Anthropogenic Biomes of the World, Version 2: 1800 data set describes anthropogenic transformations within the terrestrial biosphere caused by sustained direct...

  13. Anthropogenic Biomes of the World, Version 2: 2000

    Data.gov (United States)

    National Aeronautics and Space Administration — The Anthropogenic Biomes of the World, Version 2: 2000 data set describes anthropogenic transformations within the terrestrial biosphere caused by sustained direct...

  14. Comparative patterns of plant invasions in the Mediterranean biome.

    Science.gov (United States)

    Arianoutsou, Margarita; Delipetrou, Pinelopi; Vilà, Montserrat; Dimitrakopoulos, Panayiotis G; Celesti-Grapow, Laura; Wardell-Johnson, Grant; Henderson, Lesley; Fuentes, Nicol; Ugarte-Mendes, Eduardo; Rundel, Philip W

    2013-01-01

    The objective of this work was to compare and contrast the patterns of alien plant invasions in the world's five mediterranean-climate regions (MCRs). We expected landscape age and disturbance history to have bearing on levels of invasion. We assembled a database on naturalized alien plant taxa occurring in natural and semi-natural terrestrial habitats of all five regions (specifically Spain, Italy, Greece and Cyprus from the Mediterranean Basin, California, central Chile, the Cape Region of South Africa and Southwestern - SW Australia). We used multivariate (hierarchical clustering and NMDS ordination) trait and habitat analysis to compare characteristics of regions, taxa and habitats across the mediterranean biome. Our database included 1627 naturalized species with an overall low taxonomic similarity among the five MCRs. Herbaceous perennials were the most frequent taxa, with SW Australia exhibiting both the highest numbers of naturalized species and the highest taxonomic similarity (homogenization) among habitats, and the Mediterranean Basin the lowest. Low stress and highly disturbed habitats had the highest frequency of invasion and homogenization in all regions, and high natural stress habitats the lowest, while taxonomic similarity was higher among different habitats in each region than among regions. Our analysis is the first to describe patterns of species characteristics and habitat vulnerability for a single biome. We have shown that a broad niche (i.e. more than one habitat) is typical of naturalized plant species, regardless of their geographical area of origin, leading to potential for high homogenization within each region. Habitats of the Mediterranean Basin are apparently the most resistant to plant invasion, possibly because their landscapes are generally of relatively recent origin, but with a more gradual exposure to human intervention over a longer period.

  15. La filatelia biomédica

    OpenAIRE

    Emilio J.A. Roldán; Claudio Zuckerberg

    2011-01-01

    La temática biomédica es un capítulo extendido de la filatelia o coleccionismo de sellos postales. Inaugura la temática la imagen de la diosa Hygeia, en un sello de la isla Nevis de 1861. Los primeros médicos retratados en una estampilla son tres constitucionalistas americanos, en un ejemplar de 1869, pero recién en 1937 aparecen médicos holandeses en reconocimiento específico de sus aportes a la salud. En la Argentina la primera estampilla que oficialmente se ocupa del tema es de 1944, en ay...

  16. Antibiotic Resistance: MedlinePlus Health Topic

    Science.gov (United States)

    ... GO GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Health Topics → Antibiotic Resistance URL of this page: https://medlineplus.gov/antibioticresistance. ...

  17. Newborn Screening: MedlinePlus Health Topic

    Science.gov (United States)

    ... more articles Reference Desk Glossary (National Center for Biotechnology Information) Find an Expert Eunice Kennedy Shriver National ... other than English on Newborn Screening NIH MedlinePlus Magazine Hearing Loss: Screening Newborns Screening Newborns' Hearing Now ...

  18. MedlinePlus: Awards and Recognition

    Science.gov (United States)

    ... winner of the 2005 World Summit on the Information Society Awards for e-health. Winner of the Thomas Reuters/Frank Bradway Rogers Information Advancement Award in 2014 for MedlinePlus Connect and ...

  19. MedlinePlus Connect: How it Works

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    ... Connect → How it Works URL of this page: https://medlineplus.gov/connect/howitworks.html MedlinePlus Connect: How ... will change.) Old URLs New URLs Web Application https://apps.nlm.nih.gov/medlineplus/services/mpconnect.cfm? ...

  20. Liver Transplantation: MedlinePlus Health Topic

    Science.gov (United States)

    ... Statistics and Research The SRTR/OPTN Annual Data Report (Scientific Registry of Transplant Recipients) Clinical Trials ClinicalTrials.gov: Liver Transplantation (National Institutes of Health) Journal Articles References and abstracts from MEDLINE/PubMed (National ...

  1. Back Cover: NIH MedlinePlus Salud

    Science.gov (United States)

    ... Bar Home Current Issue Past Issues NIH MedlinePlus Salud Past Issues / Winter 2009 Table of Contents For ... this page please turn Javascript on. ¡A su salud! Los Institutos Nacionales de la Salud (NIH, por ...

  2. Female Infertility: MedlinePlus Health Topic

    Science.gov (United States)

    ... Prolactin blood test (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Female Infertility updates ... Serum progesterone Show More Show Less Related Health Topics Assisted Reproductive Technology Infertility Male Infertility National Institutes ...

  3. Mobility Aids: MedlinePlus Health Topic

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    ... Mobility Problems (AGS Foundation for Health in Aging) Topic Image MedlinePlus Email Updates Get Mobility Aids updates ... standing and walking Using a cane Related Health Topics Assistive Devices Other Languages Find health information in ...

  4. Genetic Testing: MedlinePlus Health Topic

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    ... Your Family's Health (National Institutes of Health) - PDF Topic Image MedlinePlus Email Updates Get Genetic Testing updates ... testing and your cancer risk Karyotyping Related Health Topics Birth Defects Genetic Counseling Genetic Disorders Newborn Screening ...

  5. Folic Acid: MedlinePlus Health Topic

    Science.gov (United States)

    ... acid in diet (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Folic Acid updates ... acid - test Folic acid in diet Related Health Topics Vitamins National Institutes of Health The primary NIH ...

  6. Pneumococcal Infections: MedlinePlus Health Topic

    Science.gov (United States)

    ... Prevention, Immunization Action Coalition) - PDF Also in Spanish Topic Image MedlinePlus Email Updates Get Pneumococcal Infections updates ... ray Meningitis - pneumococcal Sputum gram stain Related Health Topics Meningitis Pneumonia Sepsis Sinusitis Streptococcal Infections National Institutes ...

  7. Chiropractic: MedlinePlus Health Topic

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    ... for back pain (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Chiropractic updates by ... ENCYCLOPEDIA Chiropractic care for back pain Related Health Topics Back Pain Complementary and Integrative Medicine National Institutes ...

  8. Wilms' Tumor: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish Wilms tumor (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Wilms Tumor updates ... ENCYCLOPEDIA After chemotherapy - discharge Wilms tumor Related Health Topics Kidney Cancer National Institutes of Health The primary ...

  9. Child Safety: MedlinePlus Health Topic

    Science.gov (United States)

    ... injuries in children (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Child Safety updates ... safety Preventing head injuries in children Related Health Topics Infant and Newborn Care Internet Safety Motor Vehicle ...

  10. Diets: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish Mediterranean diet (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Diets updates by ... foods Diet-busting foods Mediterranean diet Related Health Topics Child Nutrition DASH Eating Plan Diabetic Diet Nutrition ...

  11. Colonoscopy: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish Virtual colonoscopy (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Colonoscopy updates by ... Colonoscopy Colonoscopy discharge Sigmoidoscopy Virtual colonoscopy Related Health Topics Colonic Diseases Colonic Polyps Colorectal Cancer National Institutes ...

  12. Pneumocystis Infections: MedlinePlus Health Topic

    Science.gov (United States)

    ... Pneumocystis jiroveci pneumonia (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Pneumocystis Infections updates ... GO MEDICAL ENCYCLOPEDIA Pneumocystis jiroveci pneumonia Related Health Topics HIV/AIDS HIV/AIDS and Infections Pneumonia National ...

  13. Collapsed Lung: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish Pneumothorax - infants (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Collapsed Lung updates ... Lung surgery Pneumothorax - slideshow Pneumothorax - infants Related Health Topics Chest Injuries and Disorders Lung Diseases Pleural Disorders ...

  14. Male Infertility: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish Testicular biopsy (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Male Infertility updates ... analysis Sperm release pathway Testicular biopsy Related Health Topics Assisted Reproductive Technology Female Infertility Infertility National Institutes ...

  15. Prediabetes:MedlinePlus Health Topic

    Science.gov (United States)

    ... in Spanish Prediabetes (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Prediabetes updates by ... Glucose tolerance test - non-pregnant Prediabetes Related Health Topics A1C Diabetes Diabetes in Children and Teens Diabetes ...

  16. Healthy Aging: MedlinePlus Health Topic

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    ... Aging National Institute on Aging Also in Spanish Topic Image MedlinePlus Email Updates Get Healthy Aging updates ... 65 Health screening - women - over 65 Related Health Topics Exercise for Seniors Nutrition for Seniors Seniors' Health ...

  17. Psoriatic Arthritis: MedlinePlus Health Topic

    Science.gov (United States)

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  18. Hip Replacement: MedlinePlus Health Topic

    Science.gov (United States)

    ... invasive hip replacement (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Hip Replacement updates ... replacement - precautions Minimally invasive hip replacement Related Health Topics Hip Injuries and Disorders National Institutes of Health ...

  19. Diabetes: MedlinePlus Health Topic

    Science.gov (United States)

    ... High blood sugar (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Diabetes updates by ... ketones test Show More Show Less Related Health Topics A1C Blood Sugar Diabetes and Pregnancy Diabetes Complications ...

  20. Platelet Disorders: MedlinePlus Health Topic

    Science.gov (United States)

    ... Thromobocytopenia - drug-induced (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Platelet Disorders updates ... Willebrand disease Show More Show Less Related Health Topics Bleeding Disorders Blood Clots Blood Count Tests Blood ...

  1. Cardiac Rehabilitation: MedlinePlus Health Topic

    Science.gov (United States)

    ... in Spanish Electrocardiogram (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Cardiac Rehabilitation updates ... How to take your pulse Pulse Related Health Topics Heart Attack Heart Diseases How to Prevent Heart ...

  2. Dialysis: MedlinePlus Health Topic

    Science.gov (United States)

    ... access for hemodialysis (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Dialysis updates by ... for hemodialysis Show More Show Less Related Health Topics Creatinine Kidney Cysts Kidney Failure Peritoneal Disorders National ...

  3. Eye Wear: MedlinePlus Health Topic

    Science.gov (United States)

    ... When You Exercise (National Institute on Aging) - PDF Topic Image MedlinePlus Email Updates Get Eye Wear updates by email What's this? GO Related Health Topics Refractive Errors National Institutes of Health The primary ...

  4. Cardiac Arrest: MedlinePlus Health Topic

    Science.gov (United States)

    ... Handouts Cardiac arrest (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Cardiac Arrest updates ... this? GO MEDICAL ENCYCLOPEDIA Cardiac arrest Related Health Topics Arrhythmia CPR Pacemakers and Implantable Defibrillators National Institutes ...

  5. Kawasaki Disease: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish Kawasaki disease (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Kawasaki Disease updates ... GO MEDICAL ENCYCLOPEDIA Electrocardiogram Kawasaki disease Related Health Topics Vasculitis National Institutes of Health The primary NIH ...

  6. Diabetic Diet: MedlinePlus Health Topic

    Science.gov (United States)

    ... Sweeteners - sugar substitutes (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Diabetic Diet updates ... you have diabetes Sweeteners - sugar substitutes Related Health Topics Blood Sugar Diabetes Diabetes in Children and Teens ...

  7. Infection Control: MedlinePlus Health Topic

    Science.gov (United States)

    ... Staph infections - hospital (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Infection Control updates ... infections when visiting Staph infections - hospital Related Health Topics Hepatitis HIV/AIDS MRSA National Institutes of Health ...

  8. Menopause: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish What is Menopause? (National Institute on Aging) Topic Image MedlinePlus Email Updates Get Menopause updates by ... test Menopause Types of hormone therapy Related Health Topics Hormone Replacement Therapy Menstruation Premature Ovarian Failure National ...

  9. Vaginitis: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish Vulvovaginitis - overview (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Vaginitis updates by ... Vaginitis test - wet mount Vulvovaginitis - overview Related Health Topics Trichomoniasis Vaginal Diseases Yeast Infections Other Languages Find ...

  10. Hearing Aids: MedlinePlus Health Topic

    Science.gov (United States)

    ... for hearing loss (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Hearing Aids updates ... MEDICAL ENCYCLOPEDIA Devices for hearing loss Related Health Topics Cochlear Implants Hearing Disorders and Deafness National Institutes ...

  11. Kidney Tests: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish Total protein (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Kidney Tests updates ... hour volume Show More Show Less Related Health Topics Kidney Cancer Kidney Diseases National Institutes of Health ...

  12. Ischemic Stroke: MedlinePlus Health Topic

    Science.gov (United States)

    ... Spanish Thrombolytic therapy (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Ischemic Stroke updates ... cardiogenic embolism Stroke - slideshow Thrombolytic therapy Related Health Topics Hemorrhagic Stroke Stroke Stroke Rehabilitation National Institutes of ...

  13. Pulmonary Rehabilitation: MedlinePlus Health Topic

    Science.gov (United States)

    ... Handouts Postural drainage (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Pulmonary Rehabilitation updates ... this? GO MEDICAL ENCYCLOPEDIA Postural drainage Related Health Topics Lung Diseases National Institutes of Health The primary ...

  14. Environmental history of the dry forest biome of Guerrero, Mexico, and human impact during the last c. 2700 years

    NARCIS (Netherlands)

    Berrio, J.C.; Hooghiemstra, H.; van Geel, B.; Ludlow-Wiegers, B.

    2006-01-01

    Two lake sediment cores from Madre del Sur mountain range, Guerrero State, west-central Mexico were studied to examine the past dynamics of the dry forest biome. Pollen, spores of coprophilous fungi, cyanobacteria and lithological changes are presented. The 390-cm Tixtla core (17°30′N, 99°24′W, 1400

  15. La filatelia biomédica

    Directory of Open Access Journals (Sweden)

    Emilio J.A. Roldán

    2011-02-01

    Full Text Available La temática biomédica es un capítulo extendido de la filatelia o coleccionismo de sellos postales. Inaugura la temática la imagen de la diosa Hygeia, en un sello de la isla Nevis de 1861. Los primeros médicos retratados en una estampilla son tres constitucionalistas americanos, en un ejemplar de 1869, pero recién en 1937 aparecen médicos holandeses en reconocimiento específico de sus aportes a la salud. En la Argentina la primera estampilla que oficialmente se ocupa del tema es de 1944, en ayuda de las víctimas del terremoto de San Juan. Florentino Ameghino es el primer científico incluido en 1954, y en 1967 se edita un sello conmemorativo de la Dra. Cecilia Grierson. La filatelia argentina luego reconoce varios de nuestros científicos y médicos, congresos, universidades, campañas sanitarias, temas de odontología, farmacia, enfermería y otros, generando un amplio material filatélico en reconocimiento del valor social que la ciencia biomédica argentina ha logrado en el contexto propio e internacional. Posiblemente sea un científico, el Dr. Bernardo Houssay, uno de los argentinos más veces editado en distintos sellos postales de la filatelia mundial.

  16. Changes in forest productivity across Alaska consistent with biome shift.

    Science.gov (United States)

    Beck, Pieter S A; Juday, Glenn P; Alix, Claire; Barber, Valerie A; Winslow, Stephen E; Sousa, Emily E; Heiser, Patricia; Herriges, James D; Goetz, Scott J

    2011-04-01

    Global vegetation models predict that boreal forests are particularly sensitive to a biome shift during the 21st century. This shift would manifest itself first at the biome's margins, with evergreen forest expanding into current tundra while being replaced by grasslands or temperate forest at the biome's southern edge. We evaluated changes in forest productivity since 1982 across boreal Alaska by linking satellite estimates of primary productivity and a large tree-ring data set. Trends in both records show consistent growth increases at the boreal-tundra ecotones that contrast with drought-induced productivity declines throughout interior Alaska. These patterns support the hypothesized effects of an initiating biome shift. Ultimately, tree dispersal rates, habitat availability and the rate of future climate change, and how it changes disturbance regimes, are expected to determine where the boreal biome will undergo a gradual geographic range shift, and where a more rapid decline. © 2011 Blackwell Publishing Ltd/CNRS.

  17. Climate-biomes, pedo-biomes and pyro-biomes: which world view explains the tropical forest - savanna boundary in South America?

    Science.gov (United States)

    Langan, Liam; Higgins, Steven; Scheiter, Simon

    2015-04-01

    Elucidating the drivers of broad vegetation formations improves our understanding of earth system functioning. The biome, defined primarily by the dominance of a particular growth strategy, is commonly employed to group vegetation into similar units. Predicting tropical forest and savanna biome boundaries in South America has proven difficult. Process based DGVMs (Dynamic global vegetation models) are our best tool to simulate vegetation patterns, make predictions for future changes and test theory, however, many DGVMs fail to accurately simulate the spatial distribution or indeed presence of the South American savanna biome which can result in large differences in modelled ecosystem structural properties. Evidence suggests fire plays a significant role in mediating these forest and savanna biome boundaries, however, fire alone does not appear to be sufficient to predict these boundaries in South America using DGVMs hinting at the presence of one or more missing environmental factors. We hypothesise that soil depth, which affects plant available water by determining maximum storage potential and influences temporal availability, may be one of these missing environmental factors. To test our hypothesis we use a novel vegetation model, the aDGVM2. This model has been specifically designed to allow plant trait strategies, constrained by trade-offs between traits, evolve based on the abiotic and biotic conditions where the resulting community trait suites are emergent properties of model dynamics. Furthermore it considers root biomass in multiple soil layers and therefore allows the consideration of alternative rooting strategies, which in turn allows us to explore in more detail the role of soil hydraulic factors in controlling biome boundary distributions. We find that changes in soil depth, interacting with fire, affect the relative dominance of tree and grass strategies and thus the presence and spatial distribution of forest and savanna biomes in South America

  18. Pain Relievers: MedlinePlus Health Topic

    Science.gov (United States)

    ... Health) ClinicalTrials.gov: Narcotics (National Institutes of Health) Journal Articles References and abstracts from MEDLINE/PubMed (National ... Concentration Before Giving Acetaminophen to Infants (Food and Drug Administration) ... Related Health Topics Chronic Pain Medicines Opioid Abuse and Addiction Over-the-Counter Medicines Pain Other ...

  19. Heart Surgery: MedlinePlus Health Topic

    Science.gov (United States)

    ... Living With Related Issues Specifics See, Play and Learn Videos and Tutorials Research Clinical Trials Journal Articles Resources ... Also in Spanish Videos and Tutorials MedlinePlus: Surgery Videos ... strategy is better to reduce postoperative stroke... Article: Ferumoxtyol-enhanced MR ...

  20. Montane plant environments in the Fynbos Biome

    Directory of Open Access Journals (Sweden)

    B. M. Campbell

    1983-12-01

    Full Text Available Environmental data collected at 507 plots on 22 transects, and soil analytical data from 81 of these plots, have been used to describe the plant environments of the mountains in the Fynbos Biome. Two major regional gradients are recognized: a west-east gradient and a coast-interior gradient. Of particular consequence for fynbos-environment studies is the increase in the proportion of fine soil particles from west to east. At least some aspects of soil fertility also increase towards the east. The edaphic changes are paralleled by climatic changes: chiefly a decrease in the severity of summer drought towards the east. On the coast-interior gradient a major non-climatic variable in the gradient is rock cover. High rock cover is a feature of the interior ranges. Soils with organic horizons or with E horizons are a feature on the coastal mountains, but are generally lacking on the interior mountains. The other environmental gradients recognized occur on individual transects and all include edaphic variables. The rockiness-soil depth gradient, on which an increase in rockiness is associated with a decrease in soil depth and usually a decrease in clay content, tends to occur in three situations. Firstly, it is associated with local topographic variation; the shallow, rocky soils being a feature of the steeper slopes. Secondly, it is associated with the aspect gradient; the hot, dry northern aspects having shallow, rocky, less developed soils. Thirdly, it tends to be associated with the altitude-rainfall gradient: shallower soils being found at higher altitudes. It is also at higher altitudes that higher rainfall is found. Variation in oxidizable carbon is chiefly accounted for by the altitude-rainfall gradient. Whereas at a biome-wide level, aspects of soil fertility are related to soil texture, it appears that on individual transects fertility is linked to amounts of plant remains in the soil and to rainfall. Apart from these gradients, which are

  1. The Economics of Root Distributions of Terrestrial Biomes in Response to Elevated CO2

    Science.gov (United States)

    Lu, M.; Hedin, L. O. O.

    2017-12-01

    Belowground root distributions of terrestrial biomes are central to understanding soil biogeochemical processes and land carbon sink. Yet models are thus far not able to predict root distributions across plant functional groups and major biomes, limiting our ability to predict the response of land systems to elevated CO2 concentration. Of particular concern is the apparent lack of stimulation of the aboveground carbon sink despite 30% increase of atmospheric CO2 over the past half-century, and despite the clear acceleration of the land carbon sink over the same period. This apparent discrepancy in land ecosystem response has led to the proposition that changes in belowground root dynamics might be responsible for the overlooked land sink. We here present a new modeling approach for predicting the response of root biomass and soil carbon storage to increased CO2. Our approach considers the first-principle mechanisms and tradeoffs by which plants and plant roots invest carbon to gain belowground resources, in collaboration with distinct root symbioses. We allow plants to locally compete for nutrients, with the ability to allocate biomass at different depths in the soil profile. We parameterized our model using an unprecedented global dataset of root traits, and validated our biome-level predictions with a recently updated global root biomass database. Our results support the idea that plants "dig deeper" when exposed to increased CO2, and we offer an economic-based mechanism for predicting the plant root response across soil conditions, plant functional groups and major biomes. Our model also recreates the observed responses across a range of free-air CO2 enrichment experiments, including a distinct response between plants associated with ectomycorrhizal and arbuscular mycorrhizal fungi. Most broadly, our findings suggest that roots may be increasingly important in the land carbon sink, and call for a greater effort to quantify belowground responses to elevated

  2. Using an Exploratory Internet Activity & Trivia Game to Teach Students about Biomes

    Science.gov (United States)

    Richardson, Matthew L.

    2009-01-01

    Students in life science classes need an introduction to biomes, including an introduction to the concept, key biotic and abiotic features of biomes, and geographic locations of biomes. In this activity, students in seventh- and eighth-grade science classes used a directed exploratory Internet activity to learn about biomes. The author tested…

  3. Spatial Distribution of Aboveground Carbon Stock of the Arboreal Vegetation in Brazilian Biomes of Savanna, Atlantic Forest and Semi-Arid Woodland.

    Science.gov (United States)

    Scolforo, Henrique Ferraco; Scolforo, Jose Roberto Soares; Mello, Carlos Rogerio; Mello, Jose Marcio; Ferraz Filho, Antonio Carlos

    2015-01-01

    The objective of this study was to map the spatial distribution of aboveground carbon stock (using Regression-kriging) of arboreal plants in the Atlantic Forest, Semi-arid woodland, and Savanna Biomes in Minas Gerais State, southeastern Brazil. The database used in this study was obtained from 163 forest fragments, totaling 4,146 plots of 1,000 m2 distributed in these Biomes. A geographical model for carbon stock estimation was parameterized as a function of Biome, latitude and altitude. This model was applied over the samples and the residuals generated were mapped based on geostatistical procedures, selecting the exponential semivariogram theoretical model for conducting ordinary Kriging. The aboveground carbon stock was found to have a greater concentration in the north of the State, where the largest contingent of native vegetation is located, mainly the Savanna Biome, with Wooded Savanna and Shrub Savanna phytophysiognomes. The largest weighted averages of carbon stock per hectare were found in the south-center region (48.6 Mg/ha) and in the southern part of the eastern region (48.4 Mg/ha) of Minas Gerais State, due to the greatest predominance of Atlantic Forest Biome forest fragments. The smallest weighted averages per hectare were found in the central (21.2 Mg/ha), northern (20.4 Mg/ha), and northwestern (20.7 Mg/ha) regions of Minas Gerais State, where Savanna Biome fragments are predominant, in the phytophysiognomes Wooded Savanna and Shrub Savanna.

  4. Structural characterization of vegetation in the fynbos biome

    CSIR Research Space (South Africa)

    Campbell, BM

    1981-08-01

    Full Text Available A proposed system for the standardization of descriptive terminology for structural characterization of vegetation in the Fynbos Biome is presented in tabular form. Specific applications of the system are described and illustrations of some...

  5. Forest resilience to drought varies across biomes.

    Science.gov (United States)

    Gazol, Antonio; Camarero, Jesus Julio; Vicente-Serrano, Sergio M; Sánchez-Salguero, Raúl; Gutiérrez, Emilia; de Luis, Martin; Sangüesa-Barreda, Gabriel; Novak, Klemen; Rozas, Vicente; Tíscar, Pedro A; Linares, Juan C; Martín-Hernández, Natalia; Martínez Del Castillo, Edurne; Ribas, Montse; García-González, Ignacio; Silla, Fernando; Camisón, Alvaro; Génova, Mar; Olano, José M; Longares, Luis A; Hevia, Andrea; Tomás-Burguera, Miquel; Galván, J Diego

    2018-05-01

    Forecasted increase drought frequency and severity may drive worldwide declines in forest productivity. Species-level responses to a drier world are likely to be influenced by their functional traits. Here, we analyse forest resilience to drought using an extensive network of tree-ring width data and satellite imagery. We compiled proxies of forest growth and productivity (TRWi, absolutely dated ring-width indices; NDVI, Normalized Difference Vegetation Index) for 11 tree species and 502 forests in Spain corresponding to Mediterranean, temperate, and continental biomes. Four different components of forest resilience to drought were calculated based on TRWi and NDVI data before, during, and after four major droughts (1986, 1994-1995, 1999, and 2005), and pointed out that TRWi data were more sensitive metrics of forest resilience to drought than NDVI data. Resilience was related to both drought severity and forest composition. Evergreen gymnosperms dominating semi-arid Mediterranean forests showed the lowest resistance to drought, but higher recovery than deciduous angiosperms dominating humid temperate forests. Moreover, semi-arid gymnosperm forests presented a negative temporal trend in the resistance to drought, but this pattern was absent in continental and temperate forests. Although gymnosperms in dry Mediterranean forests showed a faster recovery after drought, their recovery potential could be constrained if droughts become more frequent. Conversely, angiosperms and gymnosperms inhabiting temperate and continental sites might have problems to recover after more intense droughts since they resist drought but are less able to recover afterwards. © 2018 John Wiley & Sons Ltd.

  6. Pollen-based biome reconstructions for Latin America at 0, 6000 and 18 000 radiocarbon years

    Science.gov (United States)

    Marchant, R.; Harrison, S.P.; Hooghiemstra, H.; Markgraf, Vera; Van Boxel, J. H.; Ager, T.; Almeida, L.; Anderson, R.; Baied, C.; Behling, H.; Berrio, J.C.; Burbridge, R.; Bjorck, S.; Byrne, R.; Bush, M.B.; Cleef, A.M.; Duivenvoorden, J.F.; Flenley, J.R.; De Oliveira, P.; Van Geel, B.; Graf, K.J.; Gosling, W.D.; Harbele, S.; Van Der Hammen, T.; Hansen, B.C.S.; Horn, S.P.; Islebe, G.A.; Kuhry, P.; Ledru, M.-P.; Mayle, F.E.; Leyden, B.W.; Lozano-Garcia, S.; Melief, A.B.M.; Moreno, P.; Moar, N.T.; Prieto, A.; Van Reenen, G. B.; Salgado-Labouriau, M. L.; Schasignbitz, F.; Schreve-Brinkman, E. J.; Wille, M.

    2009-01-01

    The biomisation method is used to reconstruct Latin American vegetation at 6000±500 and 18 000±1000 radiocarbon years before present (14C yr BP) from pollen data. Tests using modern pollen data from 381 samples derived from 287 locations broadly reproduce potential natural vegetation. The strong temperature gradient associated with the Andes is recorded by a transition from high altitude cool grass/shrubland and cool mixed forest to mid-altitude cool temperate rain forest, to tropical dry, seasonal and rain forest at low altitudes. Reconstructed biomes from a number of sites do not match the potential vegetation due to local factors such as human impact, methodological artefacts and mechanisms of pollen representivity of the parent vegetation. At 6000±500 14C yr BP 255 samples are analysed from 127 sites. Differences between the modern and the 6000±500 14C yr BP reconstruction are comparatively small. Patterns of change relative to the modern reconstruction are mainly to biomes characteristic of drier climate in the north of the region with a slight more mesic shift in the south. Cool temperate rain forest remains dominant in western South America. In northwestern South America a number of sites record transitions from tropical seasonal forest to tropical dry forest and tropical rain forest to tropical seasonal forest. Sites in Central America also show a change in biome assignment to more mesic vegetation, indicative of greater plant available moisture, e.g. on the Yucat??n peninsula sites record warm evergreen forest, replacing tropical dry forest and warm mixed forest presently recorded. At 18 000±1000 14C yr BP 61 samples from 34 sites record vegetation that reflects a generally cool and dry environment. Cool grass/shrubland prevalent in southeast Brazil, Amazonian sites record tropical dry forest, warm temperate rain forest and tropical seasonal forest. Southernmost South America is dominated by cool grass/shrubland, a single site retains cool temperate

  7. Dynamic vegetation modeling of tropical biomes during Heinrich events

    Science.gov (United States)

    Handiani, Dian Noor; Paul, André; Dupont, Lydie M.

    2010-05-01

    Heinrich events are thought to be associated with a slowdown of the Atlantic Meridional Overturning Circulation (AMOC), which in turn would lead to a cooling of the North Atlantic Ocean and a warming of the South Atlantic Ocean (the "bipolar seesaw" hypothesis). The accompanying abrupt climate changes occurred not only in the ocean but also on the continents. Changes were strongest in the Northern Hemisphere but were registered in the tropics as well. Pollen data from Angola and Brazil showed that climate changes during Heinrich events affected vegetation patterns very differently in eastern South America and western Africa. To understand the differential response in the terrestrial tropics, we studied the vegetation changes during Heinrich events by using a dynamic global vegetation model (TRIFFID) as part of the University of Victoria (UVic) Earth System-Climate Model (ESCM). The model results show a bipolar seesaw pattern in temperature and precipitation during a near-collapse of the AMOC. The succession in plant-functional types (PFTs) showed changes from forest to shrubs to desert, including spreading desert in northwest Africa, retreating broadleaf trees in West Africa and northern South America, but advancing broadleaf trees in Brazil. The pattern is explained by a southward shift of the tropical rainbelt resulting in a strong decrease in precipitation over northwest and West Africa as well as in northern South America, but an increase in precipitation in eastern Brazil. To facilitate the comparison between modeled vegetation results with pollen data, we diagnosed the distribution of biomes from the PFT coverage and the simulated model climate. The biome distribution was computed for Heinrich event 1 and the Last Glacial Maximum as well as for pre-industrial conditions. We used a classification of biomes in terms of "mega-biomes", which were defined following a scheme originally proposed by BIOME 6000 (v 4.2). The biome distribution of the Sahel region

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  12. On coupling global biome models with climate models

    OpenAIRE

    Claussen, M.

    1994-01-01

    The BIOME model of Prentice et al. (1992; J. Biogeogr. 19: 117-134), which predicts global vegetation patterns in equilibrium with climate, was coupled with the ECHAM climate model of the Max-Planck-Institut fiir Meteorologie, Hamburg, Germany. It was found that incorporation of the BIOME model into ECHAM, regardless at which frequency, does not enhance the simulated climate variability, expressed in terms of differences between global vegetation patterns. Strongest changes are seen only betw...

  13. Diverging responses of tropical Andean biomes under future climate conditions.

    Directory of Open Access Journals (Sweden)

    Carolina Tovar

    Full Text Available Observations and projections for mountain regions show a strong tendency towards upslope displacement of their biomes under future climate conditions. Because of their climatic and topographic heterogeneity, a more complex response is expected for biodiversity hotspots such as tropical mountain regions. This study analyzes potential changes in the distribution of biomes in the Tropical Andes and identifies target areas for conservation. Biome distribution models were developed using logistic regressions. These models were then coupled to an ensemble of 8 global climate models to project future distribution of the Andean biomes and their uncertainties. We analysed projected changes in extent and elevational range and identified regions most prone to change. Our results show a heterogeneous response to climate change. Although the wetter biomes exhibit an upslope displacement of both the upper and the lower boundaries as expected, most dry biomes tend to show downslope expansion. Despite important losses being projected for several biomes, projections suggest that between 74.8% and 83.1% of the current total Tropical Andes will remain stable, depending on the emission scenario and time horizon. Between 3.3% and 7.6% of the study area is projected to change, mostly towards an increase in vertical structure. For the remaining area (13.1%-17.4%, there is no agreement between model projections. These results challenge the common believe that climate change will lead to an upslope displacement of biome boundaries in mountain regions. Instead, our models project diverging responses, including downslope expansion and large areas projected to remain stable. Lastly, a significant part of the area expected to change is already affected by land use changes, which has important implications for management. This, and the inclusion of a comprehensive uncertainty analysis, will help to inform conservation strategies in the Tropical Andes, and to guide similar

  14. Generality of leaf trait relationships: A test across six biomes

    Energy Technology Data Exchange (ETDEWEB)

    Reich, P.B. [Univ. of Minnesota, Saint Paul, MN (United States). Dept. of Forest Resources; Ellsworth, D.S. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science; Walters, M.B. [Michigan State Univ., East Lansing, MI (United States). Dept. of Forestry; Vose, J.M. [Forest Service, Otto, NC (United States). Coweeta Hydrological Lab.; Gresham, C. [Clemson Univ., Georgetown, SC (United States). Baruch Forest Inst.; Volin, J.C. [Florida Atlantic Univ., Davie, FL (United States). Div. of Science; Bowman, W.D. [Inst. of Arctic and Alpine Research, Boulder, CO (United States). Mountain Research Station]|[Univ. of Colorado, Boulder, CO (United States). Dept. of Evolutionary, Population, and Organismic Biology

    1999-09-01

    Convergence in interspecific leaf trait relationships across diverse taxonomic groups and biomes would have important evolutionary and ecological implications. Such convergence has been hypothesized to result from trade-offs that limit the combination of plant traits for any species. Here the authors address this issue by testing for biome differences in the slope and intercept of interspecific relationships among leaf traits: longevity, net photosynthetic capacity (A{sub max}), leaf diffusive conductance (G{sub S}), specific leaf area (SLA), and nitrogen (N) status, for more than 100 species in six distinct biomes of the Americas. The six biomes were: alpine tundra-subalpine forest ecotone, cold temperate forest-prairie ecotone, montane cool temperate forest, desert shrubland, subtropical forest, and tropical rain forest. Despite large differences in climate and evolutionary history, in all biomes mass-based leaf N (N{sub mass}), SLA, G{sub S}, and A{sub max} were positively related to one another and decreased with increasing leaf life span. The relationships between pairs of leaf traits exhibited similar slopes among biomes, suggesting a predictable set of scaling relationships among key leaf morphological, chemical, and metabolic traits that are replicated globally among terrestrial ecosystems regardless of biome or vegetation type. However, the intercept (i.e., the overall elevation of regression lines) of relationships between pairs of leaf traits usually differed among biomes. With increasing aridity across sites, species had greater A{sub max} for a given level of G{sub S} and lower SLA for any given leaf life span. Using principal components analysis, most variation among species was explained by an axis related to mass-based leaf traits (A{sub max}, N, and SLA) while a second axis reflected climate, G{sub S}, and other area-based leaf traits.

  15. Modelling insights on the partition of evapotranspiration components across biomes

    Science.gov (United States)

    Fatichi, Simone; Pappas, Christoforos

    2017-04-01

    Recent studies using various methodologies have found a large variability (from 35 to 90%) in the ratio of transpiration to total evapotranspiration (denoted as T:ET) across biomes or even at the global scale. Concurrently, previous results suggest that T:ET is independent of mean precipitation and has a positive correlation with Leaf Area Index (LAI). We used the mechanistic ecohydrological model, T&C, with a refined process-based description of soil resistance and a detailed treatment of canopy biophysics and ecophysiology, to investigate T:ET across multiple biomes. Contrary to observation-based estimates, simulation results highlight a well-constrained range of mean T:ET across biomes that is also robust to perturbations of the most sensitive parameters. Simulated T:ET was confirmed to be independent of average precipitation, while it was found to be uncorrelated with LAI across biomes. Higher values of LAI increase evaporation from interception but suppress ground evaporation with the two effects largely cancelling each other in many sites. These results offer mechanistic, model-based, evidence to the ongoing research about the range of T:ET and the factors affecting its magnitude across biomes.

  16. Combating HIV/AIDS | NIH MedlinePlus the Magazine

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    Skip to main content NIH MedlinePlus the Magazine NIH MedlinePlus Salud Download the Current Issue PDF [3.1 mb] Trusted Health Information from the National Institutes of Health Home Current Issue ...

  17. Helping others hear better | NIH MedlinePlus the Magazine

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  18. Mary Tyler Moore Helps Launch NIH MedlinePlus Magazine

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  1. Exploring Graphic Medicine | NIH MedlinePlus the Magazine

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  14. Conserving the Brazilian semiarid (Caatinga) biome under climate change

    DEFF Research Database (Denmark)

    Oliveira, Guilherme de; Bastos Araujo, Miguel; Rangel, Thiago Fernado

    2012-01-01

    to assess changes in climate suitability across individual species ranges, ensemble forecasting was used based on seven bioclimatic envelope models, three atmosphere–ocean general circulation models, and two greenhouse emission gas scenarios for 2020, 2050, and 2080. We found that most species will gain...... additional threats to the biome’s biodiversity. Here, we ask if the remnants of natural vegetation in Caatinga biome, where endemic terrestrial vertebrate species occur, are likely to retain more climatic suitability under climate change scenarios than other less pristine areas of the biome. In order......The Caatinga is a semiarid biome of the northeast of Brazil with only 1 % of its territory currently conserved. The biome’s biodiversity is highly threatened due to exposure to land conversion for agricultural and cattle ranch. Climate forecasts predict increases in aridity, which could pose...

  15. Subscribe to NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... turn Javascript on. Subscribe to NIH MedlinePlus the magazine NIH MedlinePlus the magazine is published quarterly, in print and on the ... up for a free subscription to NIH MedlinePlus Magazine. Librarians may order this magazine in bulk . Please ...

  16. Remotely sensed phenology for mapping biomes and vegetation functional types

    CSIR Research Space (South Africa)

    Wessels, Konrad J

    2009-07-01

    Full Text Available clearly captured in Fig. 3. The majority of the pixels in the Savanna have a start of growing season in late October, midposition in February and end in June (Fig. 3). In contrast, the winter rainfall Succulent Karoo have a start of growing season... initially split the biomes based on vegetation production and then by the seasonality of growth IV - 1035 (Fig. 4). The three arid biomes (Desert, Succulent and Nama Figure 3. Frequency histograms of the mean START, midposition (MID) and END date...

  17. La prosodia como identificador biométrico

    OpenAIRE

    Farrús i Cabeceran, Mireia

    2011-01-01

    La biometría tiene como objetivo el reconocimiento de personas mediante uno o más identificadores biométricos como la voz, la cara o las huellas dactilares, entre otros. Gracias a la buena aceptación social y el poco intrusismo en los individuos, la voz ha sido, tradicionalmente, uno de los identificadores más utilizados en los sistemas biométricos. Estos sistemas de reconocimiento basados en la voz utilizan, habitualmente, características relacionadas con el espectro de la voz. No obstante, ...

  18. Karoo biome: a preliminary sythesis. Part 1 - physical environment

    CSIR Research Space (South Africa)

    Cowling, RM

    1986-01-01

    Full Text Available . It is a multi-authored publication covering a wide range of topics. This first volume summarizes what is currently known on the physical environment of the biome; namely geology, soils, climate, hydrology, geohydrology and soil erosion. Other aspects...

  19. Importance of soil-water to the Caatinga biome, Brazil

    NARCIS (Netherlands)

    Alves Rodrigues Pinheiro, Everton; Metselaar, Klaas; Jong van Lier, de Quirijn; Araújo, de José Carlos

    2016-01-01

    Northeastern Brazil is hydrologically characterized by recurrent droughts leading to a highly vulnerable natural water resource system. The region contains the Caatinga biome, covering an area of approximately 800000km2. To increase insight in water balance components for this sparsely

  20. South African Red Data Book: Plants - fynbos and Karoo biomes

    CSIR Research Space (South Africa)

    Hall, AV

    1985-01-01

    Full Text Available In this report a list is given of 1 808 rare, threatened and recently extinct plants in the fynbos and karoo biomes in the Cape Province of South Africa. The area covers the south-western and southern Cape, Namaqualand and the Karoo. Following...

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

    Science.gov (United States)

    Chuixiang Yi; Daniel Ricciuto; Runze Li; John Wolbeck; Xiyan Xu; Mats Nilsson; John Frank; William J. Massman

    2010-01-01

    Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmosphere across biomes...

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

    Czech Academy of Sciences Publication Activity Database

    Yi, C.; Ricciuto, D.; Marek, Michal V.

    2010-01-01

    Roč. 5, č. 3 (2010), s. 034007 ISSN 1748-9326 Institutional research plan: CEZ:AV0Z60870520 Keywords : NEE * climate control * terrestrial carbon sequestration * temperature * dryness * eddy flux * biomes * photosynthesis * respiration * global carbon cycle Subject RIV: EH - Ecology, Behaviour Impact factor: 3.049, year: 2010

  3. Anthropogenic biomes: a key contribution to earth-system science

    Science.gov (United States)

    Lilian Alessa; F. Stuart Chapin

    2008-01-01

    Human activities now dominate most of the ice-free terrestrial surface. A recent article presents a classification and global map of human-influenced biomes of the world that provides a novel and potentially appropriate framework for projecting changes in earth-system dynamics.

  4. The effect of heterogeneous landscape dynamics on ecotone types at two convergent semi-arid biomes

    Science.gov (United States)

    Landscapes in biome transition zones consist of a mosaic of patches dominated or codominated by species from adjacent biomes. Shifts in the vegetation composition and dynamics of a biome transition zone depend upon the underlying patch dynamics of the ecotones between these dominant species. Landsca...

  5. Importance of ecotone type to landscape dynamics at biome transition zones

    Science.gov (United States)

    Landscapes in biome transition zones consist of a mosaic of patches dominated or codominated by species from adjacent biomes. Shifts in the vegetation composition and dynamics of a biome transition zone depend upon the underlying patch dynamics of the ecotones between these dominant species. Landsc...

  6. Birth of a biome: insights into the assembly and maintenance of the Australian arid zone biota.

    Science.gov (United States)

    Byrne, M; Yeates, D K; Joseph, L; Kearney, M; Bowler, J; Williams, M A J; Cooper, S; Donnellan, S C; Keogh, J S; Leys, R; Melville, J; Murphy, D J; Porch, N; Wyrwoll, K-H

    2008-10-01

    The integration of phylogenetics, phylogeography and palaeoenvironmental studies is providing major insights into the historical forces that have shaped the Earth's biomes. Yet our present view is biased towards arctic and temperate/tropical forest regions, with very little focus on the extensive arid regions of the planet. The Australian arid zone is one of the largest desert landform systems in the world, with a unique, diverse and relatively well-studied biota. With foci on palaeoenvironmental and molecular data, we here review what is known about the assembly and maintenance of this biome in the context of its physical history, and in comparison with other mesic biomes. Aridification of Australia began in the Mid-Miocene, around 15 million years, but fully arid landforms in central Australia appeared much later, around 1-4 million years. Dated molecular phylogenies of diverse taxa show the deepest divergences of arid-adapted taxa from the Mid-Miocene, consistent with the onset of desiccation. There is evidence of arid-adapted taxa evolving from mesic-adapted ancestors, and also of speciation within the arid zone. There is no evidence for an increase in speciation rate during the Pleistocene, and most arid-zone species lineages date to the Pliocene or earlier. The last 0.8 million years have seen major fluctuations of the arid zone, with large areas covered by mobile sand dunes during glacial maxima. Some large, vagile taxa show patterns of recent expansion and migration throughout the arid zone, in parallel with the ice sheet-imposed range shifts in Northern Hemisphere taxa. Yet other taxa show high lineage diversity and strong phylogeographical structure, indicating persistence in multiple localised refugia over several glacial maxima. Similar to the Northern Hemisphere, Pleistocene range shifts have produced suture zones, creating the opportunity for diversification and speciation through hybridisation, polyploidy and parthenogenesis. This review highlights

  7. NEE and GPP dynamic evolution at two biomes in the upper Spanish plateau

    Science.gov (United States)

    Sánchez, María Luisa; Pardo, Nuria; Pérez, Isidro Alberto; García, Maria de los Angeles

    2014-05-01

    In order to assess the ability of dominant biomes to act as a CO2 sink, two eddy correlation stations close to each other in central Spain have been concurrently operational since March 2008 until the present. The land use of the first station, AC, is a rapeseed rotating crop consisting of annual rotation of non-irrigated rapeseed, barley, peas, rye, and sunflower, respectively. The land use of the second, CIBA, is a mixture of open shrubs/crops, with open shrubs being markedly dominant. The period of measurements covered variable general meteorological conditions. 2009 and 2012 were dominated by drought, whereas 2010 was the rainiest year. Annual rainfall during 2008 and 2009 was close to the historical averaged annual means. This paper presents the dynamic evolution of NEE-8d and GPP-8d observed at the AC station over five years and compares the results with those concurrently observed at the CIBA station. GGP 8-d estimates at both stations were determined using a Light Use Efficiency Model, LUE. Input data for the LUE model were the FPAR 8-d products supplied by MODIS, PAR in situ measurements, and a scalar f, varying between 0 and 1, to take account of the reduction in maximum PAR conversion efficiency, ɛ0, under limiting environmental conditions. f values were assumed to be dependent on air temperature and evaporative fraction, EF, which was considered a proxy of soil moisture. ɛ0, a key parameter, which depends on land use types, was derived through the results of a linear regression fit between the GPP 8-d eddy covariance composites observed and the LUE concurrent 8-d model estimates. Over the five-year study period, both biomes behaved as CO2 sinks. However, the ratio of the NEE-8d total accumulated at AC and CIBA, respectively, was close to a factor two, revealing the effectiveness of the studied crops as CO2 sinks. On an annual basis, accumulated NEE-8d exhibited major variability in both biomes. At CIBA, the results were largely dominated by the

  8. Terrestrial ecology. Comprehensive study of the grassland biome

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Terrestrial ecology and grassland biome studies are designed to characterize the biota of the Hanford Reservation, elucidate seasonal dynamics of plant productivity, decomposition and mineral behavior patterns of important plant communities, and, to study the response of these communities to important natural environmental stresses, such as weather, wildfire and man-induced alterations of communities (influenced by grazing cattle and severe mechanical disturbance of the soil, such as affected by plowing or burial of waste materials or construction activities). A detailed account of the important findings of a 5-yr study is currently being prepared by the terrestrial ecology section staff for publication as a contribution to the International Biological Program Grassland Biome project

  9. BIOME: A browser-aware search and order system

    Science.gov (United States)

    Grubb, Jon W.; Jennings, Sarah V.; Yow, Teresa G.; Daughterty, Patricia F.

    1996-01-01

    The Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC), which is associated with NASA's Earth Observing System Data and Information System (EOSDIS), provides access to a large number of tabular and imagery datasets used in ecological and environmental research. Because of its large and diverse data holdings, the challenge for the ORNL DAAC is to help users find data of interest from the hundreds of thousands of files available at the DAAC without overwhelming them. Therefore, the ORNL DAAC developed the Biogeochemical Information Ordering Management Environment (BIOME), a search and order system for the World Wide Web (WWW). The WWW provides a new vehicle that allows a wide range of users access to the data. This paper describes the specialized attributes incorporated into BIOME that allow researchers easy access to an otherwise bewildering array of data products.

  10. Pennsylvanian coniferopsid forests in sabkha facies reveal the nature of seasonal tropical biome

    Science.gov (United States)

    Falcon-Lang, H. J.; Jud, N.A.; John, Nelson W.; DiMichele, W.A.; Chaney, D.S.; Lucas, S.G.

    2011-01-01

    Pennsylvanian fossil forests are known from hundreds of sites across tropical Pangea, but nearly all comprise remains of humid Coal Forests. Here we report a unique occurrence of seasonally dry vegetation, preserved in growth position along >5 km of strike, in the Pennsylvanian (early Kasimovian, Missourian) of New Mexico (United States). Analyses of stump anatomy, diameter, and spatial density, coupled with observations of vascular traces and associated megaflora, show that this was a deciduous, mixed-age, coniferopsid woodland (~100 trees per hectare) with an open canopy. The coniferopsids colonized coastal sabkha facies and show tree rings, confirming growth under seasonally dry conditions. Such woodlands probably served as the source of coniferopsids that replaced Coal Forests farther east in central Pangea during drier climate phases. Thus, the newly discovered woodland helps unravel biome-scale vegetation dynamics and allows calibration of climate models. ?? 2011 Geological Society of America.

  11. Multiple nutrient stresses at intersecting Pacific Ocean biomes detected by protein biomarkers.

    Science.gov (United States)

    Saito, Mak A; McIlvin, Matthew R; Moran, Dawn M; Goepfert, Tyler J; DiTullio, Giacomo R; Post, Anton F; Lamborg, Carl H

    2014-09-05

    Marine primary productivity is strongly influenced by the scarcity of required nutrients, yet our understanding of these nutrient limitations is informed by experimental observations with sparse geographical coverage and methodological limitations. We developed a quantitative proteomic method to directly assess nutrient stress in high-light ecotypes of the abundant cyanobacterium Prochlorococcus across a meridional transect in the central Pacific Ocean. Multiple peptide biomarkers detected widespread and overlapping regions of nutritional stress for nitrogen and phosphorus in the North Pacific Subtropical Gyre and iron in the equatorial Pacific. Quantitative protein analyses demonstrated simultaneous stress for these nutrients at biome interfaces. This application of proteomic biomarkers to diagnose ocean metabolism demonstrated Prochlorococcus actively and simultaneously deploying multiple biochemical strategies for low-nutrient conditions in the oceans. Copyright © 2014, American Association for the Advancement of Science.

  12. Parameterisation of Biome BGC to assess forest ecosystems in Africa

    Science.gov (United States)

    Gautam, Sishir; Pietsch, Stephan A.

    2010-05-01

    African forest ecosystems are an important environmental and economic resource. Several studies show that tropical forests are critical to society as economic, environmental and societal resources. Tropical forests are carbon dense and thus play a key role in climate change mitigation. Unfortunately, the response of tropical forests to environmental change is largely unknown owing to insufficient spatially extensive observations. Developing regions like Africa where records of forest management for long periods are unavailable the process-based ecosystem simulation model - BIOME BGC could be a suitable tool to explain forest ecosystem dynamics. This ecosystem simulation model uses descriptive input parameters to establish the physiology, biochemistry, structure, and allocation patterns within vegetation functional types, or biomes. Undocumented parameters for larger-resolution simulations are currently the major limitations to regional modelling in African forest ecosystems. This study was conducted to document input parameters for BIOME-BGC for major natural tropical forests in the Congo basin. Based on available literature and field measurements updated values for turnover and mortality, allometry, carbon to nitrogen ratios, allocation of plant material to labile, cellulose, and lignin pools, tree morphology and other relevant factors were assigned. Daily climate input data for the model applications were generated using the statistical weather generator MarkSim. The forest was inventoried at various sites and soil samples of corresponding stands across Gabon were collected. Carbon and nitrogen in the collected soil samples were determined from soil analysis. The observed tree volume, soil carbon and soil nitrogen were then compared with the simulated model outputs to evaluate the model performance. Furthermore, the simulation using Congo Basin specific parameters and generalised BIOME BGC parameters for tropical evergreen broadleaved tree species were also

  13. Softball Games Bring NCI and Leidos Biomed Employees Together | Poster

    Science.gov (United States)

    NCI and Leidos Biomed employees took to the fields at Nallin Pond for the third annual slow-pitch softball games on August 26. The series attracted 54 employees who were divided into four teams, Red, Blue, Gray, and White, and they were cheered on by about 40 enthusiastic spectators. In the first set of games, the Gray team defeated the Blue team, 15–8, and the White team

  14. Pollen-based biome reconstructions for Latin America at 0, 6000 and 18 000 radiocarbon years ago

    Science.gov (United States)

    Marchant, R.; Cleef, A.; Harrison, S.P.; Hooghiemstra, H.; Markgraf, Vera; Van Boxel, J.; Ager, T.; Almeida, L.; Anderson, R.; Baied, C.; Behling, H.; Berrio, J.C.; Burbridge, R.; Bjorck, S.; Byrne, R.; Bush, M.; Duivenvoorden, J.; Flenley, J.; De Oliveira, P.; Van Gee, B.; Graf, K.; Gosling, W.D.; Harbele, S.; Van Der Hammen, T.; Hansen, B.; Horn, S.; Kuhry, P.; Ledru, M.-P.; Mayle, F.; Leyden, B.; Lozano-Garcia, S.; Melief, A.M.; Moreno, P.; Moar, N.T.; Prieto, A.; Van Reenen, G.; Salgado-Labouriau, M.; Schabitz, F.; Schreve-Brinkman, E. J.; Wille, M.

    2009-01-01

    The biomisation method is used to reconstruct Latin American vegetation at 6000??500 and 18 000??1000 radiocarbon years before present ( 14C yr BP) from pollen data. Tests using modern pollen data from 381 samples derived from 287 locations broadly reproduce potential natural vegetation. The strong temperature gradient associated with the Andes is recorded by a transition from high altitude cool grass/shrubland and cool mixed forest to mid-altitude cool temperate rain forest, to tropical dry, seasonal and rain forest at low altitudes. Reconstructed biomes from a number of sites do not match the potential vegetation due to local factors such as human impact, methodological artefacts and mechanisms of pollen representivity of the parent vegetation. At 6000??500 14C yr BP 255 samples are analysed from 127 sites. Differences between the modern and the 6000??500 14C yr BP reconstruction are comparatively small; change relative to the modern reconstruction are mainly to biomes characteristic of drier climate in the north of the region with a slight more mesic shift in the south. Cool temperate rain forest remains dominant in western South America. In northwestern South America a number of sites record transitions from tropical seasonal forest to tropical dry forest and tropical rain forest to tropical seasonal forest. Sites in Central America show a change in biome assignment, but to more mesic vegetation, indicative of greater plant available moisture, e.g. on the Yucat??n peninsula sites record warm evergreen forest, replacing tropical dry forest and warm mixed forest presently recorded. At 18 000??1000 14C yr BP 61 samples from 34 sites record vegetation reflecting a generally cool and dry environment. Cool grass/shrubland is prevalent in southeast Brazil whereas Amazonian sites record tropical dry forest, warm temperate rain forest and tropical seasonal forest. Southernmost South America is dominated by cool grass/shrubland, a single site retains cool temperate rain

  15. NIH Institutes and MLN MedlinePlus Advisory Board

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    ... JavaScript. Answer: MedlinePlus is a selected list of authoritative resources. MedlinePlus uses quality guidelines to evaluate Web ... ensure that the information we link to is authoritative, accurate, up-to-date, educational and available at ...

  17. Constrained variability of modeled T:ET ratio across biomes

    Science.gov (United States)

    Fatichi, Simone; Pappas, Christoforos

    2017-07-01

    A large variability (35-90%) in the ratio of transpiration to total evapotranspiration (referred here as T:ET) across biomes or even at the global scale has been documented by a number of studies carried out with different methodologies. Previous empirical results also suggest that T:ET does not covary with mean precipitation and has a positive dependence on leaf area index (LAI). Here we use a mechanistic ecohydrological model, with a refined process-based description of evaporation from the soil surface, to investigate the variability of T:ET across biomes. Numerical results reveal a more constrained range and higher mean of T:ET (70 ± 9%, mean ± standard deviation) when compared to observation-based estimates. T:ET is confirmed to be independent from mean precipitation, while it is found to be correlated with LAI seasonally but uncorrelated across multiple sites. Larger LAI increases evaporation from interception but diminishes ground evaporation with the two effects largely compensating each other. These results offer mechanistic model-based evidence to the ongoing research about the patterns of T:ET and the factors influencing its magnitude across biomes.

  18. A dated phylogeny and collection records reveal repeated biome shifts in the African genus Coccinia (Cucurbitaceae).

    Science.gov (United States)

    Holstein, Norbert; Renner, Susanne S

    2011-01-26

    Conservatism in climatic tolerance may limit geographic range expansion and should enhance the effects of habitat fragmentation on population subdivision. Here we study the effects of historical climate change, and the associated habitat fragmentation, on diversification in the mostly sub-Saharan cucurbit genus Coccinia, which has 27 species in a broad range of biota from semi-arid habitats to mist forests. Species limits were inferred from morphology, and nuclear and plastid DNA sequence data, using multiple individuals for the widespread species. Climatic tolerances were assessed from the occurrences of 1189 geo-referenced collections and WorldClim variables. Nuclear and plastid gene trees included 35 or 65 accessions, representing up to 25 species. The data revealed four species groups, one in southern Africa, one in Central and West African rain forest, one widespread but absent from Central and West African rain forest, and one that occurs from East Africa to southern Africa. A few individuals are differently placed in the plastid and nuclear (LFY) trees or contain two ITS sequence types, indicating hybridization. A molecular clock suggests that the diversification of Coccinia began about 6.9 Ma ago, with most of the extant species diversity dating to the Pliocene. Ancestral biome reconstruction reveals six switches between semi-arid habitats, woodland, and forest, and members of several species pairs differ significantly in their tolerance of different precipitation regimes. The most surprising findings of this study are the frequent biome shifts (in a relatively small clade) over just 6 - 7 million years and the limited diversification during and since the Pleistocene. Pleistocene climate oscillations may have been too rapid or too shallow for full reproductive barriers to develop among fragmented populations of Coccinia, which would explain the apparently still ongoing hybridization between certain species. Steeper ecological gradients in East Africa and

  19. A dated phylogeny and collection records reveal repeated biome shifts in the African genus Coccinia (Cucurbitaceae

    Directory of Open Access Journals (Sweden)

    Renner Susanne S

    2011-01-01

    Full Text Available Abstract Background Conservatism in climatic tolerance may limit geographic range expansion and should enhance the effects of habitat fragmentation on population subdivision. Here we study the effects of historical climate change, and the associated habitat fragmentation, on diversification in the mostly sub-Saharan cucurbit genus Coccinia, which has 27 species in a broad range of biota from semi-arid habitats to mist forests. Species limits were inferred from morphology, and nuclear and plastid DNA sequence data, using multiple individuals for the widespread species. Climatic tolerances were assessed from the occurrences of 1189 geo-referenced collections and WorldClim variables. Results Nuclear and plastid gene trees included 35 or 65 accessions, representing up to 25 species. The data revealed four species groups, one in southern Africa, one in Central and West African rain forest, one widespread but absent from Central and West African rain forest, and one that occurs from East Africa to southern Africa. A few individuals are differently placed in the plastid and nuclear (LFY trees or contain two ITS sequence types, indicating hybridization. A molecular clock suggests that the diversification of Coccinia began about 6.9 Ma ago, with most of the extant species diversity dating to the Pliocene. Ancestral biome reconstruction reveals six switches between semi-arid habitats, woodland, and forest, and members of several species pairs differ significantly in their tolerance of different precipitation regimes. Conclusions The most surprising findings of this study are the frequent biome shifts (in a relatively small clade over just 6 - 7 million years and the limited diversification during and since the Pleistocene. Pleistocene climate oscillations may have been too rapid or too shallow for full reproductive barriers to develop among fragmented populations of Coccinia, which would explain the apparently still ongoing hybridization between certain

  20. FIFE data analysis: Testing BIOME-BGC predictions for grasslands

    Science.gov (United States)

    Hunt, E. Raymond, Jr.

    1994-01-01

    The First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) was conducted in a 15 km by 15 km research area located 8 km south of Manhattan, Kansas. The site consists primarily of native tallgrass prairie mixed with gallery oak forests and croplands. The objectives of FIFE are to better understand the role of biology in controlling the interactions between the land and the atmosphere, and to determine the value of remotely sensed data for estimating climatological parameters. The goals of FIFE are twofold: the upscale integration of models, and algorithm development for satellite remote sensing. The specific objectives of the field campaigns carried out in 1987 and 1989 were the simultaneous acquisition of satellite, atmospheric, and surface data; and the understanding of the processes controlling surface energy and mass exchange. Collected data were used to study the dynamics of various ecosystem processes (photosynthesis, evaporation and transpiration, autotrophic and heterotrophic respiration, etc.). Modelling terrestrial ecosystems at scales larger than that of a homogeneous plot led to the development of simple, generalized models of biogeochemical cycles that can be accurately applied to different biomes through the use of remotely sensed data. A model was developed called BIOME-BGC (for BioGeochemical Cycles) from a coniferous forest ecosystem model, FOREST-BGC, where a biome is considered a combination of a life forms in a specified climate. A predominately C4-photosynthetic grassland is probably the most different from a coniferous forest possible, hence the FIFE site was an excellent study area for testing BIOME-BGC. The transition from an essentially one-dimensional calculation to three-dimensional, landscape scale simulations requires the introduction of such factors as meteorology, climatology, and geomorphology. By using remotely sensed geographic information data for important model inputs, process

  1. Use of BIOME-BGC to simulate water and carbon fluxes within Mediterranean macchia

    OpenAIRE

    Chiesi M; Chirici G; Corona P; Duce P; Salvati R; Spano D; Vaccari FP; Maselli F

    2012-01-01

    The biogeochemical model BIOME-BGC is capable to estimate the main ecophysiological processes characterising all terrestrial ecosystems. To this aim it needs to be properly adapted to reproduce the behaviour of each biome type through a calibration phase. The aim of this paper is to adapt BIOME-BGC to reproduce the evapotranspiration (ET) and photosynthesis (GPP) of Mediterranean macchia spread all over Italy. Ten different sites were selected in the Centre-South of Italy and their gross prim...

  2. Welcome to NIH MedlinePlus, the magazine

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    ... from the world's largest medical library, NIH's National Library of Medicine. MedlinePlus has extensive information from the NIH and other trusted sources on more than 700 diseases and conditions. There ...

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  1. Evaluating fire danger in Brazilian biomes: present and future patterns

    Science.gov (United States)

    Silva, Patrícia; Bastos, Ana; DaCamara, Carlos; Libonati, Renata

    2017-04-01

    Climate change is expected to have a significant impact on fire occurrence and activity, particularly in Brazil, a region known to be fire-prone [1]. The Brazilian savanna, commonly referred to as cerrado, is a fire-adapted biome covering more than 20% of the country's total area. It presents the highest numbers of fire events, making it particularly susceptible to changes in climate. It is thus essential to understand the present fire regimes in Brazilian biomes, in order to better evaluate future patterns. The CPTEC/INPE, the Brazilian Center for Weather Forecasting and Climate Research at the Brazilian National Institute of Space Research developed a fire danger index based on the occurrence of hundreds of thousands of fire events in the main Brazilian biomes [2]: the Meteorological Fire Danger Index (MFDI). This index indicates the predisposition of vegetation to be burned on a given day, for given climate conditions preceding that day. It relies on daily values of air temperature, relative humidity, accumulated precipitation and vegetation cover. In this study we aim to access the capability of the MFDI to accurately replicate present fire conditions for different biomes, with a special focus on cerrado. To this end, we assess the link between the MFDI as calculated by three different reanalysis (ERA-Interim, NCEP/DOE Reanalysis 2 and MERRA-2) and the observed burned area. We further calculate the validated MFDI using a regional climate model, the RCA4 as forced by EC-Earth from CORDEX, to understand the ability of the model to characterize present fire danger. Finally, the need to calibrate the model to better characterize future fire danger was also evaluated. This work was developed within the framework of the Brazilian Fire-Land-Atmosphere System (BrFLAS) Project financed by the Portuguese and Brazilian science foundations, FCT and FAPESP (project references FAPESP/1389/2014 and 2014/20042-2). [1] KRAWCHUK, M.A.; MORITZ, M.A.; PARISIEN, M.A.; VAN DORN, J

  2. Ticks parasitizing bats (Mammalia: Chiroptera) in the Caatinga Biome, Brazil.

    Science.gov (United States)

    Luz, Hermes Ribeiro; Muñoz-Leal, Sebastián; Almeida, Juliana Cardoso de; Faccini, João Luiz Horacio; Labruna, Marcelo Bahia

    2016-01-01

    In this paper, the authors report ticks parasitizing bats from the Serra das Almas Natural Reserve (RPPN) located in the municipality of Crateús, state of Ceará, in the semiarid Caatinga biome of northeastern Brazil. The study was carried out during nine nights in the dry season (July 2012) and 10 nights in the rainy season (February 2013). Only bats of the Phyllostomidae and Mormoopidae families were parasitized by ticks. The species Artibeus planirostris and Carolia perspicillata were the most parasitized. A total of 409 larvae were collected and classified into three genera: Antricola (n = 1), Nothoaspis (n = 1) and Ornithodoros (n = 407). Four species were morphologically identified as Nothoaspis amazoniensis, Ornithodoros cavernicolous, Ornithodoros fonsecai, Ornithodoros hasei, and Ornithodoros marinkellei. Ornithodoros hasei was the most common tick associated with bats in the current study. The present study expand the distributional ranges of at least three soft ticks into the Caatinga biome, and highlight an unexpected richness of argasid ticks inhabiting this arid ecosystem.

  3. Ticks parasitizing bats (Mammalia: Chiroptera in the Caatinga Biome, Brazil

    Directory of Open Access Journals (Sweden)

    Hermes Ribeiro Luz

    Full Text Available Abstract In this paper, the authors report ticks parasitizing bats from the Serra das Almas Natural Reserve (RPPN located in the municipality of Crateús, state of Ceará, in the semiarid Caatinga biome of northeastern Brazil. The study was carried out during nine nights in the dry season (July 2012 and 10 nights in the rainy season (February 2013. Only bats of the Phyllostomidae and Mormoopidae families were parasitized by ticks. The species Artibeus planirostris and Carolia perspicillata were the most parasitized. A total of 409 larvae were collected and classified into three genera: Antricola (n = 1, Nothoaspis (n = 1 and Ornithodoros (n = 407. Four species were morphologically identified as Nothoaspis amazoniensis, Ornithodoros cavernicolous, Ornithodoros fonsecai, Ornithodoros hasei, and Ornithodoros marinkellei. Ornithodoros hasei was the most common tick associated with bats in the current study. The present study expand the distributional ranges of at least three soft ticks into the Caatinga biome, and highlight an unexpected richness of argasid ticks inhabiting this arid ecosystem.

  4. biojs-io-biom, a BioJS component for handling data in Biological Observation Matrix (BIOM format [version 2; referees: 1 approved, 2 approved with reservations

    Directory of Open Access Journals (Sweden)

    Markus J. Ankenbrand

    2017-01-01

    Full Text Available The Biological Observation Matrix (BIOM format is widely used to store data from high-throughput studies. It aims at increasing interoperability of bioinformatic tools that process this data. However, due to multiple versions and implementation details, working with this format can be tricky. Currently, libraries in Python, R and Perl are available, whilst such for JavaScript are lacking. Here, we present a BioJS component for parsing BIOM data in all format versions. It supports import, modification, and export via a unified interface. This module aims to facilitate the development of web applications that use BIOM data. Finally, we demonstrate its usefulness by two applications that already use this component. Availability: https://github.com/molbiodiv/biojs-io-biom, https://dx.doi.org/10.5281/zenodo.218277

  5. Pollen-based biome reconstruction for southern Europe and Africa 18,000 yr BP

    NARCIS (Netherlands)

    Elenga, H; Peyron, O; Bonnefille, R; Jolly, D; Cheddadi, R; Guiot, J; Andrieu, [No Value; Bottema, S; Buchet, G; de Beaulieu, JL; Hamilton, AC; Maley, J; Marchant, R; Perez-Obiol, R; Reille, M; Riollet, G; Scott, L; Straka, H; Taylor, D; Van Campo, E; Vincens, A; Laarif, F; Jonson, H

    Pollen data from 18,000 C-14 yr sp were compiled in order to reconstruct biome distributions at the last glacial maximum in southern Europe and Africa. Biome reconstructions were made using the objective biomization method applied to pollen counts using a complete list of dryland taxa wherever

  6. Factors affecting ammonium uptake in streams - an inter-biome perspective

    Science.gov (United States)

    Jackson R Webster; Partick J. Mulholland; Jennifer L. Tanks; H. Maurice Valett; Walter K. Dodds; Bruce J. Peterson; William B. Bowden; Clifford N. Dahm; Stuart Findlay; Stanley V. Gregory; Nancy B. Grimm; Stephen K. Hamilton; Sherri L. Johnson; Eugenia Marti; William H. McDowell; Judy L. Meyer; Donna D. Morrall; Steven A. Thomas; Wilfred M. Wollhem

    2003-01-01

    1. The Lotic Intersite Nitrogen experiment (LINX) was a coordinated study of the relationships between North American biomes and factors governing ammonium uptake in streams. Our objective was to relate inter-biome variability of ammonium uptake to physical, chemical and biological processes. 2. Data were collected from 11 streams ranging from arctic to tropical and...

  7. Increasing atmospheric CO2 overrides the historical legacy of multiple stable biome states in Africa.

    Science.gov (United States)

    Moncrieff, Glenn R; Scheiter, Simon; Bond, William J; Higgins, Steven I

    2014-02-01

    The dominant vegetation over much of the global land surface is not predetermined by contemporary climate, but also influenced by past environmental conditions. This confounds attempts to predict current and future biome distributions, because even a perfect model would project multiple possible biomes without knowledge of the historical vegetation state. Here we compare the distribution of tree- and grass-dominated biomes across Africa simulated using a dynamic global vegetation model (DGVM). We explicitly evaluate where and under what conditions multiple stable biome states are possible for current and projected future climates. Our simulation results show that multiple stable biomes states are possible for vast areas of tropical and subtropical Africa under current conditions. Widespread loss of the potential for multiple stable biomes states is projected in the 21st Century, driven by increasing atmospheric CO2 . Many sites where currently both tree-dominated and grass-dominated biomes are possible become deterministically tree-dominated. Regions with multiple stable biome states are widespread and require consideration when attempting to predict future vegetation changes. Testing for behaviour characteristic of systems with multiple stable equilibria, such as hysteresis and dependence on historical conditions, and the resulting uncertainty in simulated vegetation, will lead to improved projections of global change impacts. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  8. Climate change in Inner Mongolia from 1955 to 2005-trends at regional, biome and local scales

    Energy Technology Data Exchange (ETDEWEB)

    Lu, N; Wilske, B; John, R; Chen, J [Department of Environmental Sciences, University of Toledo, Toledo, OH 43606 (United States); Ni, J, E-mail: nan.lu@utoledo.ed, E-mail: burkhard.wilske@utoledo.ed, E-mail: jni@ibcas.ac.c, E-mail: ranjeet.john@utoledo.ed, E-mail: jiquan.chen@utoledo.ed [Alfred Wegener Institute for Polar and Marine Research, Telegrafenberg A43, D-14473 Potsdam (Germany)

    2009-10-15

    This study investigated the climate change in Inner Mongolia based on 51 meteorological stations from 1955 to 2005. The climate data was analyzed at the regional, biome (i.e. forest, grassland and desert) and station scales, with the biome scale as our primary focus. The climate records showed trends of warmer and drier conditions in the region. The annual daily mean, maximum and minimum temperature increased whereas the diurnal temperature range (DTR) decreased. The decreasing trend of annual precipitation was not significant. However, the vapor pressure deficit (VPD) increased significantly. On the decadal scale, the warming and drying trends were more significant in the last 30 years than the preceding 20 years. The climate change varied among biomes, with more pronounced changes in the grassland and the desert biomes than in the forest biome. DTR and VPD showed the clearest inter-biome gradient from the lowest rate of change in the forest biome to the highest rate of change in the desert biome. The rates of change also showed large variations among the individual stations. Our findings correspond with the IPCC predictions that the future climate will vary significantly by location and through time, suggesting that adaptation strategies also need to be spatially viable.

  9. S2Biom database with logistical components of the biomass value chain

    NARCIS (Netherlands)

    Annevelink, E.; Groot, de H.L.E.; Shah, N.; Giarola, S.; Pantaleo, M.; Anttila, P.; Vis, Martijn; Raa, te Rik; Berg, van den Douwe; Gabrielle, B.

    2015-01-01

    The S2Biom project (www.s2biom.eu) - Delivery of sustainable supply of non-food biomass to support
    a resource-efficient Bioeconomy in Europe - supports sustainable delivery chains of non-food biomass feedstock.
    This poses a logistical challenge because the quality and handling

  10. Climate change in Inner Mongolia from 1955 to 2005-trends at regional, biome and local scales

    International Nuclear Information System (INIS)

    Lu, N; Wilske, B; John, R; Chen, J; Ni, J

    2009-01-01

    This study investigated the climate change in Inner Mongolia based on 51 meteorological stations from 1955 to 2005. The climate data was analyzed at the regional, biome (i.e. forest, grassland and desert) and station scales, with the biome scale as our primary focus. The climate records showed trends of warmer and drier conditions in the region. The annual daily mean, maximum and minimum temperature increased whereas the diurnal temperature range (DTR) decreased. The decreasing trend of annual precipitation was not significant. However, the vapor pressure deficit (VPD) increased significantly. On the decadal scale, the warming and drying trends were more significant in the last 30 years than the preceding 20 years. The climate change varied among biomes, with more pronounced changes in the grassland and the desert biomes than in the forest biome. DTR and VPD showed the clearest inter-biome gradient from the lowest rate of change in the forest biome to the highest rate of change in the desert biome. The rates of change also showed large variations among the individual stations. Our findings correspond with the IPCC predictions that the future climate will vary significantly by location and through time, suggesting that adaptation strategies also need to be spatially viable.

  11. Mid- to Late-Holocene pollen-based biome reconstructions for Colombia

    NARCIS (Netherlands)

    Marchant, R.; Behling, H.; Berrío, J.C.; Cleef, A.M.; Duivenvoorden, J.; Hooghiemstra, H.; Kuhry, P.; Melief, B.; Geel, van B.; Hammen, van der T.; Reenen, van T.; Wille, M.

    2001-01-01

    The assignment of Colombian pollen data to biomes allows the data to be synthesised at 10 `time windows' from the present-day to 6000 radiocarbon years before present (BP). The modern reconstructed biomes are compared to a map of modern potential vegetation to check the applicability of the method

  12. Identification of biomes affected by marginal expansion of agricultural land use induced by increased crop consumption

    DEFF Research Database (Denmark)

    Kløverpris, Jesper Hedal

    2009-01-01

    to characterise these areas. The present study ascribes so-called biomes (natural potential vegetation) to the areas affected by agricultural expansion in order to provide a basis for assessing the environmental impacts from land use in the life cycle impact assessment (LCIA). The methodology builds...... on agricultural statistics and maps of global agricultural areas and the global distribution of biomes. The application of the method is illustrated with four examples. The results indicate that agricultural expansion on land suited for crop cultivation (cultivable land) typically affects forest biomes...... or potential grassland/steppe, whereas expansion on land suited for grazing but not for crop cultivation (grazable land) typically occurs on potential shrubland or a few other biomes depending on the region. Some uncertainty applies to the results but it is concluded that it is feasible to identify biomes...

  13. Climate and litter quality differently modulate the effects of soil fauna on litter decomposition across biomes.

    Science.gov (United States)

    García-Palacios, Pablo; Maestre, Fernando T; Kattge, Jens; Wall, Diana H

    2013-08-01

    Climate and litter quality have been identified as major drivers of litter decomposition at large spatial scales. However, the role played by soil fauna remains largely unknown, despite its importance for litter fragmentation and microbial activity. We synthesised litterbag studies to quantify the effect sizes of soil fauna on litter decomposition rates at the global and biome scales, and to assess how climate, litter quality and soil fauna interact to determine such rates. Soil fauna consistently enhanced litter decomposition at both global and biome scales (average increment ~ 37%). [corrected]. However, climate and litter quality differently modulated the effects of soil fauna on decomposition rates between biomes, from climate-driven biomes to those where climate effects were mediated by changes in litter quality. Our results advocate for the inclusion of biome-specific soil fauna effects on litter decomposition as a mean to reduce the unexplained variation in large-scale decomposition models. © 2013 John Wiley & Sons Ltd/CNRS.

  14. PubMed alternatives to search MEDLINE: An environmental scan

    Directory of Open Access Journals (Sweden)

    Arun Keepanasseril

    2014-01-01

    Full Text Available The prime objective of this article is to introduce the newer methods to access, search and process MEDLINE citations. It also aims to provide a brief overview of each service′s salient features. A targeted search was conducted in MEDLINE through the OVID gateway. This was followed with a search in Google Scholar as well as Google and Bing. Ninety-two web-based services that can be used to search MEDLINE were identified. The list was shortened to 24 by applying a set of relevancy criteria to select those services more relevant to general medical and dental users. Salient features of the selected services are outlined and a use case based classification of the system has been proposed to help dental practitioners and researchers select the appropriate service for a given purpose.

  15. Supplementary searches of PubMed to improve currency of MEDLINE and MEDLINE In-Process searches via Ovid.

    Science.gov (United States)

    Duffy, Steven; de Kock, Shelley; Misso, Kate; Noake, Caro; Ross, Janine; Stirk, Lisa

    2016-10-01

    The research investigated whether conducting a supplementary search of PubMed in addition to the main MEDLINE (Ovid) search for a systematic review is worthwhile and to ascertain whether this PubMed search can be conducted quickly and if it retrieves unique, recently published, and ahead-of-print studies that are subsequently considered for inclusion in the final systematic review. Searches of PubMed were conducted after MEDLINE (Ovid) and MEDLINE In-Process (Ovid) searches had been completed for seven recent reviews. The searches were limited to records not in MEDLINE or MEDLINE In-Process (Ovid). Additional unique records were identified for all of the investigated reviews. Search strategies were adapted quickly to run in PubMed, and reviewer screening of the results was not time consuming. For each of the investigated reviews, studies were ordered for full screening; in six cases, studies retrieved from the supplementary PubMed searches were included in the final systematic review. Supplementary searching of PubMed for studies unavailable elsewhere is worthwhile and improves the currency of the systematic reviews.

  16. MeSHmap: a text mining tool for MEDLINE.

    OpenAIRE

    Srinivasan, P.

    2001-01-01

    Our research goal is to explore text mining from the metadata included in MEDLINE documents. We present MeSHmap our prototype text mining system that exploits the MeSH indexing accompanying MEDLINE records. MeSHmap supports searches via PubMed followed by user driven exploration of the MeSH terms and subheadings in the retrieved set. The potential of the system goes beyond text retrieval. It may also be used to compare entities of the same type such as pairs of drugs or pairs of procedures et...

  17. Climate sensitivity of shrub growth across the tundra biome

    DEFF Research Database (Denmark)

    Myers-Smith, Isla H.; Elmendorf, Sarah C.; Beck, Pieter S.A.

    2015-01-01

    Rapid climate warming in the tundra biome has been linked to increasing shrub dominance1–4. Shrub expansion can modify climate by altering surface albedo, energy and water balance, and permafrost2,5–8, yet the drivers of shrub growth remain poorly understood. Dendroecological data consisting...... of multi-decadal time series of annual shrub growth provide an underused resource to explore climate–growth relationships. Here, we analyse circumpolar data from 37 Arctic and alpine sites in 9 countries, including 25 species, and 42,000 annual growth records from 1,821 individuals. Our analyses...... demonstrate that the sensitivity of shrub growth to climate was: (1) heterogeneous, with European sites showing greater summer temperature sensitivity than North American sites, and (2) higher at sites with greater soil moisture and for taller shrubs (for example, alders and willows) growing at their northern...

  18. Uso de bases de datos bibliográficas por investigadores biomédicos latinoamericanos hispanoparlantes: estudio transversal The use of bibliographic databases by Spanish-speaking Latin American biomedical researchers: a cross-sectional study

    OpenAIRE

    Edgar Guillermo Ospina; Ludovic Reveiz Herault; Andrés Felipe Cardona

    2005-01-01

    OBJETIVO: Caracterizar cómo los profesionales biomédicos hispanoparlantes de América Latina acceden a y utilizan las bases de datos bibliográficas. MÉTODOS: A partir de una búsqueda en MEDLINE se identificaron 2 515 artículos publicados entre agosto de 2002 y agosto de 2003 por autores de Argentina, Bolivia, Chile, Colombia, Costa Rica, Cuba, Ecuador, Guatemala, Honduras, México, Nicaragua, Panamá, Paraguay, Perú, Uruguay y Venezuela. La búsqueda se limitó a referencias de las ciencias básica...

  19. Improved simulation of poorly drained forests using Biome-BGC.

    Science.gov (United States)

    Bond-Lamberty, Ben; Gower, Stith T; Ahl, Douglas E

    2007-05-01

    Forested wetlands and peatlands are important in boreal and terrestrial biogeochemical cycling, but most general-purpose forest process models are designed and parameterized for upland systems. We describe changes made to Biome-BGC, an ecophysiological process model, that improve its ability to simulate poorly drained forests. Model changes allowed for: (1) lateral water inflow from a surrounding watershed, and variable surface and subsurface drainage; (2) adverse effects of anoxic soil on decomposition and nutrient mineralization; (3) closure of leaf stomata in flooded soils; and (4) growth of nonvascular plants (i.e., bryophytes). Bryophytes were treated as ectohydric broadleaf evergreen plants with zero stomatal conductance, whose cuticular conductance to CO(2) was dependent on plant water content. Individual model changes were parameterized with published data, and ecosystem-level model performance was assessed by comparing simulated output to field data from the northern BOREAS site in Manitoba, Canada. The simulation of the poorly drained forest model exhibited reduced decomposition and vascular plant growth (-90%) compared with that of the well-drained forest model; the integrated bryophyte photosynthetic response accorded well with published data. Simulated net primary production, biomass and soil carbon accumulation broadly agreed with field measurements, although simulated net primary production was higher than observed data in well-drained stands. Simulated net primary production in the poorly drained forest was most sensitive to oxygen restriction on soil processes, and secondarily to stomatal closure in flooded conditions. The modified Biome-BGC remains unable to simulate true wetlands that are subject to prolonged flooding, because it does not track organic soil formation, water table changes, soil redox potential or anaerobic processes.

  20. Two New Species and New Occurrences of Syneches Walker for Brazilian Biome of Caatinga (Diptera: Hybotidae: Hybotinae).

    Science.gov (United States)

    Soares, M M M; Ale-Rocha, R

    2018-03-13

    Syneches from Brazilian biome of Caatinga were studied, two new species are described, Syneches atratus sp. nov. and Syneches limeirai sp. nov., and three species, Syneches annulipes Bezzi, 1909, Syneches moraballi Smith, 1963, and Syneches rafaeli Ale-Rocha & Vieira, 2008, are recorded for the biome. An identification key for the species of Syneches from Caatinga biome is provided.

  1. Pacemakers and Implantable Defibrillators: MedlinePlus Health Topic

    Science.gov (United States)

    ... ClinicalTrials.gov: Pacemaker, Artificial (National Institutes of Health) Journal Articles References and abstracts from MEDLINE/PubMed (National ... Leadless Cardiac Pacemakers: The Next Evolution in Pacemaker Technology. ... on Pacemakers and Implantable Defibrillators is the National Heart, Lung, and Blood Institute Other Languages Find health information in languages other than English on Pacemakers and ...

  2. Welcome to MedlinePlus en español

    Science.gov (United States)

    ... para el público de la Biblioteca Nacional de Medicina, la biblioteca médica más grande del mundo. Los ... B. Lindberg, M.D. Director, Biblioteca Nacional de Medicina MedlinePlus.gov/salud Spring 2007 Issue: Volume 2 ...

  3. Comparing Medline citations using modified N-grams

    Science.gov (United States)

    Nawab, Rao Muhammad Adeel; Stevenson, Mark; Clough, Paul

    2014-01-01

    Objective We aim to identify duplicate pairs of Medline citations, particularly when the documents are not identical but contain similar information. Materials and methods Duplicate pairs of citations are identified by comparing word n-grams in pairs of documents. N-grams are modified using two approaches which take account of the fact that the document may have been altered. These are: (1) deletion, an item in the n-gram is removed; and (2) substitution, an item in the n-gram is substituted with a similar term obtained from the Unified Medical Language System  Metathesaurus. N-grams are also weighted using a score derived from a language model. Evaluation is carried out using a set of 520 Medline citation pairs, including a set of 260 manually verified duplicate pairs obtained from the Deja Vu database. Results The approach accurately detects duplicate Medline document pairs with an F1 measure score of 0.99. Allowing for word deletions and substitution improves performance. The best results are obtained by combining scores for n-grams of length 1–5 words. Discussion Results show that the detection of duplicate Medline citations can be improved by modifying n-grams and that high performance can also be obtained using only unigrams (F1=0.959), particularly when allowing for substitutions of alternative phrases. PMID:23715801

  4. Death, dying and informatics: misrepresenting religion on MedLine.

    Science.gov (United States)

    Rodríguez Del Pozo, Pablo; Fins, Joseph J

    2005-07-01

    The globalization of medical science carries for doctors worldwide a correlative duty to deepen their understanding of patients' cultural contexts and religious backgrounds, in order to satisfy each as a unique individual. To become better informed, practitioners may turn to MedLine, but it is unclear whether the information found there is an accurate representation of culture and religion. To test MedLine's representation of this field, we chose the topic of death and dying in the three major monotheistic religions. We searched MedLine using PubMed in order to retrieve and thematically analyze full-length scholarly journal papers or case reports dealing with religious traditions and end-of-life care. Our search consisted of a string of words that included the most common denominations of the three religions, the standard heading terms used by the National Reference Center for Bioethics Literature (NRCBL), and the Medical Subject Headings (MeSH) used by the National Library of Medicine. Eligible articles were limited to English-language papers with an abstract. We found that while a bibliographic search in MedLine on this topic produced instant results and some valuable literature, the aggregate reflected a selection bias. American writers were over-represented given the global prevalence of these religious traditions. Denominationally affiliated authors predominated in representing the Christian traditions. The Islamic tradition was under-represented. MedLine's capability to identify the most current, reliable and accurate information about purely scientific topics should not be assumed to be the same case when considering the interface of religion, culture and end-of-life care.

  5. Death, dying and informatics: misrepresenting religion on MedLine

    Directory of Open Access Journals (Sweden)

    Fins Joseph J

    2005-07-01

    Full Text Available Abstract Background The globalization of medical science carries for doctors worldwide a correlative duty to deepen their understanding of patients' cultural contexts and religious backgrounds, in order to satisfy each as a unique individual. To become better informed, practitioners may turn to MedLine, but it is unclear whether the information found there is an accurate representation of culture and religion. To test MedLine's representation of this field, we chose the topic of death and dying in the three major monotheistic religions. Methods We searched MedLine using PubMed in order to retrieve and thematically analyze full-length scholarly journal papers or case reports dealing with religious traditions and end-of-life care. Our search consisted of a string of words that included the most common denominations of the three religions, the standard heading terms used by the National Reference Center for Bioethics Literature (NRCBL, and the Medical Subject Headings (MeSH used by the National Library of Medicine. Eligible articles were limited to English-language papers with an abstract. Results We found that while a bibliographic search in MedLine on this topic produced instant results and some valuable literature, the aggregate reflected a selection bias. American writers were over-represented given the global prevalence of these religious traditions. Denominationally affiliated authors predominated in representing the Christian traditions. The Islamic tradition was under-represented. Conclusion MedLine's capability to identify the most current, reliable and accurate information about purely scientific topics should not be assumed to be the same case when considering the interface of religion, culture and end-of-life care.

  6. Eastern deciduous forest biome progress report, September 1, 1975--August 31, 1976

    International Nuclear Information System (INIS)

    Burgess, R.L.; Tarr, N.E.

    1978-09-01

    The report concentrates on the six projects as well as results from synthesis activities at the Lake George, Lake Wingra, and Oak Ridge sites. The centralized analysis and modeling component and the Eastern Decidious Forest Biome Information Center progress during the past year are also addressed. The project on belowground dynamics of ecosystems is investigating the allocation of phytosynthetic products into fixed or labile storage pools. Root sampling, radioactive tracer techniques, and biochemical analyses are leading to an understanding of complete tree physioogy requisite for interpreting forest growth in different environments. The Role of Consumers project has begun to document the regulatory role of heterotrophs in an array of ecosystem niches. Decomposition of woody substrates, studies of the contribution of canopy and litter arthropods to material processing, and the flow and remineralization of phosphorus in lake systems are leading to a comprehensive understanding of the role of consumer organisms in ecosystem function. The Microdynamics of Detritus project continues its investigations of carbon and nitrogen dynamics in freshwater lakes. Examination of potential pathways of detritus processing is illustrating the parts that physical and biological processes play in the breakdown of organic materials

  7. La filatelia biomédica Biomedicine philately

    Directory of Open Access Journals (Sweden)

    Emilio J.A. Roldán

    2011-02-01

    Full Text Available La temática biomédica es un capítulo extendido de la filatelia o coleccionismo de sellos postales. Inaugura la temática la imagen de la diosa Hygeia, en un sello de la isla Nevis de 1861. Los primeros médicos retratados en una estampilla son tres constitucionalistas americanos, en un ejemplar de 1869, pero recién en 1937 aparecen médicos holandeses en reconocimiento específico de sus aportes a la salud. En la Argentina la primera estampilla que oficialmente se ocupa del tema es de 1944, en ayuda de las víctimas del terremoto de San Juan. Florentino Ameghino es el primer científico incluido en 1954, y en 1967 se edita un sello conmemorativo de la Dra. Cecilia Grierson. La filatelia argentina luego reconoce varios de nuestros científicos y médicos, congresos, universidades, campañas sanitarias, temas de odontología, farmacia, enfermería y otros, generando un amplio material filatélico en reconocimiento del valor social que la ciencia biomédica argentina ha logrado en el contexto propio e internacional. Posiblemente sea un científico, el Dr. Bernardo Houssay, uno de los argentinos más veces editado en distintos sellos postales de la filatelia mundial.Biomedicine is a vast field in philately or stamp collecting. It opens the topic the image of the goddess Hygeia, issued in a stamp from Nevis Island dated 1861. The first physicians to appear printed in stamps, in 1869, were three American constitutionalists, but only in 1937 there appear Dutch physicians as an acknowledgement of their contribution to public health. In Argentina the first stamp officially related to the topic was issued in 1944, to raise funds for the victims of the San Juan earthquake. Florentino Ameghino was the first scientist included in 1954, and in 1967 a stamp was issued in honour of Dr. Cecilia Grierson. Afterwards, Argentinean philately has recognized several of our scientists and physicians, congresses, universities, health campaigns, dentistry topics

  8. Automatically identifying gene/protein terms in MEDLINE abstracts.

    Science.gov (United States)

    Yu, Hong; Hatzivassiloglou, Vasileios; Rzhetsky, Andrey; Wilbur, W John

    2002-01-01

    Natural language processing (NLP) techniques are used to extract information automatically from computer-readable literature. In biology, the identification of terms corresponding to biological substances (e.g., genes and proteins) is a necessary step that precedes the application of other NLP systems that extract biological information (e.g., protein-protein interactions, gene regulation events, and biochemical pathways). We have developed GPmarkup (for "gene/protein-full name mark up"), a software system that automatically identifies gene/protein terms (i.e., symbols or full names) in MEDLINE abstracts. As a part of marking up process, we also generated automatically a knowledge source of paired gene/protein symbols and full names (e.g., LARD for lymphocyte associated receptor of death) from MEDLINE. We found that many of the pairs in our knowledge source do not appear in the current GenBank database. Therefore our methods may also be used for automatic lexicon generation. GPmarkup has 73% recall and 93% precision in identifying and marking up gene/protein terms in MEDLINE abstracts. A random sample of gene/protein symbols and full names and a sample set of marked up abstracts can be viewed at http://www.cpmc.columbia.edu/homepages/yuh9001/GPmarkup/. Contact. hy52@columbia.edu. Voice: 212-939-7028; fax: 212-666-0140.

  9. Simulating economics and environmental impacts of beef and soybean systems in Brazil's Pamas and Amozon Biomes

    Science.gov (United States)

    Recent reductions in the deforestation of the Amazon biome have highlighted the need for the sustainable intensification of beef and commodity crop production in Brazil to increase agricultural productivity without accelerating adverse environmental impacts related to greenhouse gas emissions, eutro...

  10. Biome-BGC: Modeling Effects of Disturbance and Climate (Thornton et al. 2002)

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This archived model product contains the directions, executables, and procedures for running Biome-BGC, Version 4.1.1, to recreate the results of the...

  11. BIOME: A scientific data archive search-and-order system using browser-aware, dynamic pages

    Science.gov (United States)

    Jennings, S. V.; Yow, T. G.; Ng, V. W.

    1997-01-01

    The Oak Ridge National Laboratory's (ORNL) Distributed Active Archive Center (DAAC) is a data archive and distribution center for the National Air and Space Administration's (NASA) Earth Observing System Data and Information System (EOSDIS). Both the Earth Observing System (EOS) and EOSDIS are components of NASA's contribution to the US Global Change Research Program through its Mission to Planet Earth Program. The ORNL DAAC provides access to data used in ecological and environmental research such as global change, global warming, and terrestrial ecology. Because of its large and diverse data holdings, the challenge for the ORNL DAAC is to help users find data of interest from the hundreds of thousands of files available at the DAAC without overwhelming them. Therefore, the ORNL DAAC has developed the Biogeochemical Information Ordering Management Environment (BIOME), a customized search and order system for the World Wide Web (WWW). BIOME is a public system located at http://www-eosdis. ornl.gov/BIOME/biome.html.

  12. Biome-BGC: Modeling Carbon Dynamics in Ponderosa Pine Stands (Law et al. 2003)

    Data.gov (United States)

    National Aeronautics and Space Administration — This archived model product contains the directions, executables, and procedures for running Biome-BGC, Version 4.1.2, to recreate the results of the following...

  13. Biome-BGC: Terrestrial Ecosystem Process Model, Version 4.1.1

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Biome-BGC is a computer program that estimates fluxes and storage of energy, water, carbon, and nitrogen for the vegetation and soil components of...

  14. Biome-BGC: Terrestrial Ecosystem Process Model, Version 4.1.1

    Data.gov (United States)

    National Aeronautics and Space Administration — Biome-BGC is a computer program that estimates fluxes and storage of energy, water, carbon, and nitrogen for the vegetation and soil components of terrestrial...

  15. BIOME: An Ecosystem Remote Sensor Based on Imaging Interferometry

    Science.gov (United States)

    Peterson, David L.; Hammer, Philip; Smith, William H.; Lawless, James G. (Technical Monitor)

    1994-01-01

    Until recent times, optical remote sensing of ecosystem properties from space has been limited to broad band multispectral scanners such as Landsat and AVHRR. While these sensor data can be used to derive important information about ecosystem parameters, they are very limited for measuring key biogeochemical cycling parameters such as the chemical content of plant canopies. Such parameters, for example the lignin and nitrogen contents, are potentially amenable to measurements by very high spectral resolution instruments using a spectroscopic approach. Airborne sensors based on grating imaging spectrometers gave the first promise of such potential but the recent decision not to deploy the space version has left the community without many alternatives. In the past few years, advancements in high performance deep well digital sensor arrays coupled with a patented design for a two-beam interferometer has produced an entirely new design for acquiring imaging spectroscopic data at the signal to noise levels necessary for quantitatively estimating chemical composition (1000:1 at 2 microns). This design has been assembled as a laboratory instrument and the principles demonstrated for acquiring remote scenes. An airborne instrument is in production and spaceborne sensors being proposed. The instrument is extremely promising because of its low cost, lower power requirements, very low weight, simplicity (no moving parts), and high performance. For these reasons, we have called it the first instrument optimized for ecosystem studies as part of a Biological Imaging and Observation Mission to Earth (BIOME).

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

    Energy Technology Data Exchange (ETDEWEB)

    Yi Chuixiang; Wolbeck, John; Xu Xiyan [School of Earth and Environmental Sciences, Queens College, City University of New York, NY 11367 (United States); Ricciuto, Daniel [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Li Runze [Department of Statistics, Pennsylvania State University, University Park, PA 16802 (United States); Nilsson, Mats [Department of Forest Ecology, Swedish University of Agricultural Sciences, SE-901 83 Umeaa (Sweden); Aires, Luis [CESAM and Department of Environmental Engineering, School of Technology and Management, Polytechnic Institute of Leiria (Portugal); Albertson, John D [Department of Civil and Environmental Engineering, Duke University, Durham, NC 22708-0287 (United States); Ammann, Christof [Federal Research Station Agroscope Reckenholz-Taenikon, Reckenholzstrasse 191, 8046 Zuerich (Switzerland); Arain, M Altaf [School of Geography and Earth Sciences, McMaster University, Hamilton, ON, L8S 4K1 (Canada); De Araujo, Alessandro C [Instituto Nacional de Pesquisas da Amazonia, Programa LBA, Campus-II, Manaus-Amazonas 69060 (Brazil); Aubinet, Marc [University of Liege, Gembloux Agro-Bio Tech, Unit of Biosystem Physics, 2 Passage des Deportes, 5030 Gembloux (Belgium); Aurela, Mika [Finnish Meteorological Institute, Climate Change Research, FI-00101 Helsinki (Finland); Barcza, Zoltan [Department of Meteorology, Eoetvoes Lorand University, H-1117 Budapest, Pazmany setany 1/A (Hungary); Barr, Alan [Climate Research Division, Environment Canada, Saskatoon, SK, S7N 3H5 (Canada); Berbigier, Paul [INRA, UR1263 EPHYSE, Villenave d' Ornon F-33883 (France); Beringer, Jason [School of Geography and Environmental Science, Monash University, Clayton, Victoria 3800 (Australia); Bernhofer, Christian [Institute of Hydrology and Meteorology, Dresden University of Technology, Pienner Strasse 23, D-01737, Tharandt (Germany)

    2010-07-15

    Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO{sub 2} exchange with the atmosphere across biomes and continents are lacking. Here we present data describing the relationships between net ecosystem exchange of carbon (NEE) and climate factors as measured using the eddy covariance method at 125 unique sites in various ecosystems over six continents with a total of 559 site-years. We find that NEE observed at eddy covariance sites is (1) a strong function of mean annual temperature at mid- and high-latitudes, (2) a strong function of dryness at mid- and low-latitudes, and (3) a function of both temperature and dryness around the mid-latitudinal belt (45 deg. N). The sensitivity of NEE to mean annual temperature breaks down at {approx} 16 deg. C (a threshold value of mean annual temperature), above which no further increase of CO{sub 2} uptake with temperature was observed and dryness influence overrules temperature influence.

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

    International Nuclear Information System (INIS)

    Yi Chuixiang; Wolbeck, John; Xu Xiyan; Ricciuto, Daniel; Li Runze; Nilsson, Mats; Aires, Luis; Albertson, John D; Ammann, Christof; Arain, M Altaf; De Araujo, Alessandro C; Aubinet, Marc; Aurela, Mika; Barcza, Zoltan; Barr, Alan; Berbigier, Paul; Beringer, Jason; Bernhofer, Christian

    2010-01-01

    Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO 2 exchange with the atmosphere across biomes and continents are lacking. Here we present data describing the relationships between net ecosystem exchange of carbon (NEE) and climate factors as measured using the eddy covariance method at 125 unique sites in various ecosystems over six continents with a total of 559 site-years. We find that NEE observed at eddy covariance sites is (1) a strong function of mean annual temperature at mid- and high-latitudes, (2) a strong function of dryness at mid- and low-latitudes, and (3) a function of both temperature and dryness around the mid-latitudinal belt (45 deg. N). The sensitivity of NEE to mean annual temperature breaks down at ∼ 16 deg. C (a threshold value of mean annual temperature), above which no further increase of CO 2 uptake with temperature was observed and dryness influence overrules temperature influence.

  18. The phylogeny and biogeography of Hakea (Proteaceae) reveals the role of biome shifts in a continental plant radiation.

    Science.gov (United States)

    Cardillo, Marcel; Weston, Peter H; Reynolds, Zoe K M; Olde, Peter M; Mast, Austin R; Lemmon, Emily M; Lemmon, Alan R; Bromham, Lindell

    2017-08-01

    The frequency of evolutionary biome shifts during diversification has important implications for our ability to explain geographic patterns of plant diversity. Recent studies present several examples of biome shifts, but whether frequencies of biome shifts closely reflect geographic proximity or environmental similarity of biomes remains poorly known. We explore this question by using phylogenomic methods to estimate the phylogeny of Hakea, a diverse Australian genus occupying a wide range of biomes. Model-based estimation of ancestral regions indicates that Hakea began diversifying in the Mediterranean biome of southern Australia in the Middle Eocene-Early Oligocene, and dispersed repeatedly into other biomes across the continent. We infer around 47 shifts between biomes. Frequencies of shifts between pairs of biomes are usually similar to those expected from their geographic connectedness or climatic similarity, but in some cases are substantially higher or lower than expected, perhaps reflecting how readily key physiological traits can be modified to adapt lineages to new environments. The history of frequent biome-shifting is reflected in the structure of present-day assemblages, which tend to be more phylogenetically diverse than null-model expectations. The case of Hakea demonstrates that the radiation of large plant clades across wide geographic areas need not be constrained by dispersal limitation or conserved adaptations to particular environments. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  19. [Limiting a Medline/PubMed query to the "best" articles using the JCR relative impact factor].

    Science.gov (United States)

    Avillach, P; Kerdelhué, G; Devos, P; Maisonneuve, H; Darmoni, S J

    2014-12-01

    Medline/PubMed is the most frequently used medical bibliographic research database. The aim of this study was to propose a new generic method to limit any Medline/PubMed query based on the relative impact factor and the A & B categories of the SIGAPS score. The entire PubMed corpus was used for the feasibility study, then ten frequent diseases in terms of PubMed indexing and the citations of four Nobel prize winners. The relative impact factor (RIF) was calculated by medical specialty defined in Journal Citation Reports. The two queries, which included all the journals in category A (or A OR B), were added to any Medline/PubMed query as a central point of the feasibility study. Limitation using the SIGAPS category A was larger than the when using the Core Clinical Journals (CCJ): 15.65% of PubMed corpus vs 8.64% for CCJ. The response time of this limit applied to the entire PubMed corpus was less than two seconds. For five diseases out of ten, limiting the citations with the RIF was more effective than with the CCJ. For the four Nobel prize winners, limiting the citations with the RIF was more effective than the CCJ. The feasibility study to apply a new filter based on the relative impact factor on any Medline/PubMed query was positive. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  20. USING LUDIC ACTIVITIES TO EXPLAIN THE BIOME CONCEPT

    Directory of Open Access Journals (Sweden)

    Aline Riccioni de Melos

    2015-12-01

    Full Text Available This paper contributes to research on the role of ludic activities in teaching and learning physical geography content during the last four years of primary school. We question the discourse that identifies students’ lack of interest as the obstacle to teaching physical geography. This study contributes by questioning this obstacle. We note that few studies exist on this topic, according to the CAPES (Coordination for higher Education Staff Development dissertation database, in 2011 only five were completed. The theoretical basis for the study considers work by Graciolli (2009, Silva et al. (2010, Rupel (2011 and Freitas and Salvi (2011, authors who defend the use of ludic activities in teaching methodology. In 2010, the “Biome Game” for 6th year students was developed based on this theoretical framework as part of the required course “Supervised Practice”. The goal of the activity was to think about how the concept of biome was created, and the methodology used valued recreational approaches. The empirical results of this experiment, which involved developing and implementing the game during the Supervised Practice course, demonstrate the importance of ludic pedagogical strategies for teaching physical geography in Brazilian primary education. O presente artigo traz contribuições de pesquisa sobre a função da ludicidade no ensino-aprendizagem de conteúdos da geografia física, no segundo segmento do ensino fundamental. Tal questão problematiza o discurso sobre o desinteresse dos alunos, como significativo obstáculo para a didática da geografia física. A pertinência do presente estudo está em reconhecer esta questão, tendo em vista que existem poucos estudos na área, totalizando em 2011, segundo o banco de dissertações da CAPES, somente cinco trabalhos concluídos. Nossa investigação dialoga com Graciolli (2009, Silva et al. (2010, Rupel (2011 e Freitas e Salvi (2011, autores dedicados à defesa da utilização de

  1. Biogeochemical cycling in terrestrial ecosystems of the Caatinga Biome.

    Science.gov (United States)

    Menezes, R S C; Sampaio, E V S B; Giongo, V; Pérez-Marin, A M

    2012-08-01

    The biogeochemical cycles of C, N, P and water, the impacts of land use in the stocks and flows of these elements and how they can affect the structure and functioning of Caatinga were reviewed. About half of this biome is still covered by native secondary vegetation. Soils are deficient in nutrients, especially N and P. Average concentrations of total soil P and C in the top layer (0-20 cm) are 196 mg kg(-1) and 9.3 g kg(-1), corresponding to C stocks around 23 Mg ha(-1). Aboveground biomass of native vegetation varies from 30 to 50 Mg ha(-1), and average root biomass from 3 to 12 Mg ha(-1). Average annual productivities and biomass accumulation in different land use systems vary from 1 to 7 Mg ha(-1) year(-1). Biological atmospheric N2 fixation is estimated to vary from 3 to 11 kg N ha(-1) year-1 and 21 to 26 kg N ha(-1) year(-1) in mature and secondary Caatinga, respectively. The main processes responsible for nutrient and water losses are fire, soil erosion, runoff and harvest of crops and animal products. Projected climate changes in the future point to higher temperatures and rainfall decreases. In face of the high intrinsic variability, actions to increase sustainability should improve resilience and stability of the ecosystems. Land use systems based on perennial species, as opposed to annual species, may be more stable and resilient, thus more adequate to face future potential increases in climate variability. Long-term studies to investigate the potential of the native biodiversity or adapted exotic species to design sustainable land use systems should be encouraged.

  2. Does a General Temperature-Dependent Q10 Model of Soil Respiration Exist at Biome and Global Scale?

    Institute of Scientific and Technical Information of China (English)

    Hua CHEN; Han-Qin TIAN

    2005-01-01

    Soil respiration (SR) is commonly modeled by a Q10 (an indicator of temperature sensitivity)function in ecosystem models. Q10is usually treated as a constant of 2 in these models, although Q10 value of SR often decreases with increasing temperatures. It remains unclear whether a general temperaturedependent Q10 model of SR exists at biome and global scale. In this paper, we have compiled the long-term Q10 data of 38 SR studies ranging from the Boreal, Temperate, to Tropical/Subtropical biome on four continents.Our analysis indicated that the general temperature-dependent biome Q10 models of SR existed, especially in the Boreal and Temperate biomes. A single-exponential model was better than a simple linear model in fitting the average Q10 values at the biome scale. Average soil temperature is a better predictor of Q10 value than average air temperature in these models, especially in the Boreal biome. Soil temperature alone could explain about 50% of the Q10 variations in both the Boreal and Temperate biome single-exponential Q10 model. Q10 value of SR decreased with increasing soil temperature but at quite different rates among the three biome Q10 models. The k values (Q10 decay rate constants) were 0.09, 0.07, and 0.02/℃ in the Boreal, Temperate, and Tropical/Subtropical biome, respectively, suggesting that Q10 value is the most sensitive to soil temperature change in the Boreal biome, the second in the Temperate biome, and the least sensitive in the Tropical/Subtropical biome. This also indirectly confirms that acclimation of SR in many soil warming experiments probably occurs. The k value in the "global" single-exponential Q10 model which combined both the Boreal and Temperate biome data set was 0.08/℃. However, the global general temperature-dependent Q10model developed using the data sets of the three biomes is not adequate for predicting Q10 values of SR globally.The existence of the general temperature-dependent Q10 models of SR in the Boreal and

  3. On the query reformulation technique for effective MEDLINE document retrieval.

    Science.gov (United States)

    Yoo, Sooyoung; Choi, Jinwook

    2010-10-01

    Improving the retrieval accuracy of MEDLINE documents is still a challenging issue due to low retrieval precision. Focusing on a query expansion technique based on pseudo-relevance feedback (PRF), this paper addresses the problem by systematically examining the effects of expansion term selection and adjustment of the term weights of the expanded query using a set of MEDLINE test documents called OHSUMED. Implementing a baseline information retrieval system based on the Okapi BM25 retrieval model, we compared six well-known term ranking algorithms for useful expansion term selection and then compared traditional term reweighting algorithms with our new variant of the standard Rocchio's feedback formula, which adopts a group-based weighting scheme. Our experimental results on the OHSUMED test collection showed a maximum improvement of 20.2% and 20.4% for mean average precision and recall measures over unexpanded queries when terms were expanded using a co-occurrence analysis-based term ranking algorithm in conjunction with our term reweighting algorithm (p-valueretrieval.

  4. 2008 Co2 Assimilation in Plants: Genome to Biome Gordon Research Conference - August 17-22

    Energy Technology Data Exchange (ETDEWEB)

    James V. Maroney

    2009-08-12

    Formerly entitled 'CO2 Fixation and Metabolism in Green Plants', this long-standing Gordon Research Conference has been held on a triennial basis since 1976. In 1990 the participants decided to alternate between sites in the U.S. and outside the U.S. The 2005 conference was held in Europe at the Centre Paul Langevin in Aussois, France, so the 2008 conference returns to a U.S. site - the University of New England in Biddeford, Maine. The 2008 conference covers basic plant research related to photosynthesis and the subsequent regulation and engineering of carbon assimilation. Approaches that range from post-genomic technologies and systems biology, through to fundamental biochemistry, physiology and molecular biology are integrated within ecological and agronomic contexts. As such, the meeting provides the rare opportunity of a single venue for discussing all aspects of the 'carbon-side' of photosynthesis - from genome to biome. The 2008 conference will include an emphasis on the central role of carbon assimilation by plants for developing new sources of bioenergy and for achieving a carbon-neutral planet. A special characteristic of this conference is its 'intimacy' with approximately 110 conferees, ranging from beginning graduate students and postdoctoral associates to leading senior plant scientists, engaged in open and forward-thinking discussions in an informal, friendly setting. With extended time devoted to discussion, and the encouragement to challenge dogma, it is unlike other meetings in the U.S. or abroad. Another novel feature of the conference is a session devoted to the latest 'hot off the press' findings by both established and early career scientists, picked from the abstracts. Together with an expanded poster discussion in the evening sessions, this session provides an opportunity for early career scientists to present interesting new data and to 'test drive' hypotheses in a collegial atmosphere.

  5. Inferring biome-scale net primary productivity from tree-ring isotopes

    Science.gov (United States)

    Pederson, N.; Levesque, M.; Williams, A. P.; Hobi, M. L.; Smith, W. K.; Andreu-Hayles, L.

    2017-12-01

    Satellite estimates of vegetation growth (net primary productivity; NPP), tree-ring records, and forest inventories indicate that ongoing climate change and rising atmospheric CO2 concentration are altering productivity and carbon storage of forests worldwide. The impact of global change on the trends of NPP, however, remain unknown because of the lack of long-term high-resolution NPP data. For the first time, we tested if annually resolved carbon (δ13C) and oxygen (δ18O) stable isotopes from the cellulose of tree rings from trees in temperate regions could be used as a tool for inferring NPP across spatiotemporal scales. We compared satellite NPP estimates from the moderate-resolution imaging spectroradiometer sensor (MODIS, product MOD17A) and a newly developed global NPP dataset derived from the Global Inventory Modeling and Mapping Studies (GIMMS) dataset to annually resolved tree-ring width and δ13C and δ18O records from four sites along a hydroclimatic gradient in Eastern and Central United States. We found strong correlations across large geographical regions between satellite-derived NPP and tree-ring isotopes that ranged from -0.40 to -0.91. Notably, tree-ring derived δ18O had the strongest relation to climate. The results were consistent among the studied tree species (Quercus rubra and Liriodendron tulipifera) and along the hydroclimatic conditions of our network. Our study indicates that tree-ring isotopes can potentially be used to reconstruct NPP in time and space. As such, our findings represent an important breakthrough for estimating long-term changes in vegetation productivity at the biome scale.

  6. Abiotic and biotic determinants of leaf carbon exchange capacity from tropical to high boreal biomes

    Science.gov (United States)

    Smith, N. G.; Dukes, J. S.

    2016-12-01

    Photosynthesis and respiration on land represent the two largest fluxes of carbon dioxide between the atmosphere and the Earth's surface. As such, the Earth System Models that are used to project climate change are high sensitive to these processes. Studies have found that much of this uncertainty is due to the formulation and parameterization of plant photosynthetic and respiratory capacity. Here, we quantified the abiotic and biotic factors that determine photosynthetic and respiratory capacity at large spatial scales. Specifically, we measured the maximum rate of Rubisco carboxylation (Vcmax), the maximum rate of Ribulose-1,5-bisphosphate regeneration (Jmax), and leaf dark respiration (Rd) in >600 individuals of 98 plant species from the tropical to high boreal biomes of Northern and Central America. We also measured a bevy of covariates including plant functional type, leaf nitrogen content, short- and long-term climate, leaf water potential, plant size, and leaf mass per area. We found that plant functional type and leaf nitrogen content were the primary determinants of Vcmax, Jmax, and Rd. Mean annual temperature and mean annual precipitation were not significant predictors of these rates. However, short-term climatic variables, specifically soil moisture and air temperature over the previous 25 days, were significant predictors and indicated that heat and soil moisture deficits combine to reduce photosynthetic capacity and increase respiratory capacity. Finally, these data were used as a model benchmarking tool for the Community Land Model version 4.5 (CLM 4.5). The benchmarking analyses determined errors in the leaf nitrogen allocation scheme of CLM 4.5. Under high leaf nitrogen levels within a plant type the model overestimated Vcmax and Jmax. This result suggested that plants were altering their nitrogen allocation patterns when leaf nitrogen levels were high, an effect that was not being captured by the model. These data, taken with models in mind

  7. Carbon emission as a function of energy generation in hydroelectric reservoirs in Brazilian dry tropical biome

    International Nuclear Information System (INIS)

    Ometto, Jean P.; Cimbleris, André C.P.; Santos, Marco A. dos; Rosa, Luiz P.; Abe, Donato; Tundisi, José G.; Stech, José L.; Barros, Nathan; Roland, Fábio

    2013-01-01

    Most energy generation globally is fueled by coal and oil, raising concerns about greenhouse gas emissions. Hydroelectric reservoirs are anthropogenic aquatic systems that occur across a wide geographical extent, and, in addition to their importance for energy production, they have the potential to release two important greenhouse gases (GHGs), carbon dioxide and methane. We report results from an extensive study of eight hydroelectric reservoirs located in central and southeastern tropical Brazil. In the Brazilian dry tropical biome reservoirs, emissions (in tons of CO 2 Eq. per MW h) varied from 0.01 to 0.55, and decreased with reservoir age. Total emissions were higher in the reservoir lake when compared to the river downstream the dam; however, emissions per unit area, in the first kilometer of the river after the dam, were higher than that in the reservoir. The results showed, despite higher carbon emissions per energy production in the youngest reservoirs, lower emission from hydroelectric reservoirs from the studied region in relation to thermo electrical supply, fueled by coal or fossil fuel. The ratio emission of GHG per MWh produced is an important parameter in evaluating the service provided by hydroelectric reservoir and for energy planning policies. - Highlights: ► Hydroelectric reservoirs construction is growing worldwide. ► The effect of hydropower reservoir in the carbon cycle is dependent on environment characteristics. ► Carbon emissions per energy production are higher in the youngest tropical savannah reservoirs. ► Methane emissions decrease with reservoir age in tropical savannah reservoirs. ► In general, the effect of hydropower in the carbon cycle is lower than other energy sources

  8. Social wasps (Polistinae from Pampa Biome: South Brazil, Northeastern Argentina and Uruguay

    Directory of Open Access Journals (Sweden)

    Alexandre Somavilla

    2017-08-01

    Full Text Available Abstract. This study aimed to determine social wasps’ species from Pampa Biome. Were examined samples of social wasps from south-central of Rio Grande do Sul state (Brazil, parts of Buenos Aires, Entre Rios, Corrientes, Cordoba, Santa Fé and La Pampa provinces (Argentina and in Uruguay maintained in the Coleção Entomológica de Santa Cruz do Sul (Santa Cruz do Sul-Brazil, American Museum of Natural History (USA, Natural History Museum (London-United Kingdom and Muséum National d’Histoire Naturelle (Paris-France. Thirty species were recorded: Agelaia (01, Brachygastra (01, Mischocyttarus (04, Polistes (15, Polybia (08 and Protonectarina (01. Vespas sociais do Bioma Pampa: sul do Brasil, nordeste da Argentina e Uruguai. Resumo. Este estudo objetivou determinar as espécies de vespas sociais provenientes do Bioma Pampa. Foram examinadas vespas sociais provenientes de coletas da região centro-sul do Rio Grande do Sul (Brasil, parte das províncias de Buenos Aires, Entre Rios, Corrientes, Cordoba, Santa Fé e La Pampa (Argentina e Uruguai depositadas na Coleção Entomológica de Santa Cruz do Sul (Santa Cruz do Sul-Brasil, American Museum of Natural History (Nova Iorque-USA, Natural History Museum (Londres-Reino Unido e Muséum National d’Histoire Naturelle (Paris-França. Trinta espécies foram registradas: Agelaia (01, Brachygastra (01, Mischocyttarus (04, Polistes (15, Polybia (08 e Protonectarina (01.

  9. Expanding the global network of protected areas to save the imperiled mediterranean biome.

    Science.gov (United States)

    Underwood, Emma C; Klausmeyer, Kirk R; Cox, Robin L; Busby, Sylvia M; Morrison, Scott A; Shaw, M Rebecca

    2009-02-01

    : Global goals established by the Convention on Biological Diversity stipulate that 10% of the world's ecological regions must be effectively conserved by 2010. To meet that goal for the mediterranean biome, at least 5% more land must be formally protected over the next few years. Although global assessments identify the mediterranean biome as a priority, without biologically meaningful analysis units, finer-resolution data, and corresponding prioritization analysis, future conservation investments could lead to more area being protected without increasing the representation of unique mediterranean ecosystems. We used standardized analysis units and six potential natural vegetation types stratified by 3 elevation zones in a global gap analysis that systematically explored conservation priorities across the mediterranean biome. The highest levels of protection were in Australia, South Africa, and California-Baja California (from 9-11%), and the lowest levels of protection were in Chile and the mediterranean Basin (biome only one of the six vegetation types--mediterranean shrubland--exceeded 10% protection. The remaining vegetation types--grassland, scrub, succulent dominated, woodland, and forest--each had biome, we identified biodiversity assemblages with 30% conversion and suggest that these assemblages be elevated to high-priority status in future conservation efforts.

  10. Evolutionary biology and anthropology suggest biome reconstitution as a necessary approach toward dealing with immune disorders.

    Science.gov (United States)

    Parker, William; Ollerton, Jeff

    2013-01-01

    Industrialized society currently faces a wide range of non-infectious, immune-related pandemics. These pandemics include a variety of autoimmune, inflammatory and allergic diseases that are often associated with common environmental triggers and with genetic predisposition, but that do not occur in developing societies. In this review, we briefly present the idea that these pandemics are due to a limited number of evolutionary mismatches, the most damaging being 'biome depletion'. This particular mismatch involves the loss of species from the ecosystem of the human body, the human biome, many of which have traditionally been classified as parasites, although some may actually be commensal or even mutualistic. This view, evolved from the 'hygiene hypothesis', encompasses a broad ecological and evolutionary perspective that considers host-symbiont relations as plastic, changing through ecological space and evolutionary time. Fortunately, this perspective provides a blueprint, termed 'biome reconstitution', for disease treatment and especially for disease prevention. Biome reconstitution includes the controlled and population-wide reintroduction (i.e. domestication) of selected species that have been all but eradicated from the human biome in industrialized society and holds great promise for the elimination of pandemics of allergic, inflammatory and autoimmune diseases.

  11. An intercomparison of biogenic emissions estimates from BEIS2 and BIOME: Reconciling the differences

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, J.G. [Alpine Geophysics, Pittsburgh, PA (United States); Emigh, R.A. [Alpine Geophysics, Boulder, CO (United States); Pierce, T.E. [Atmospheric Characterization and Modeling Division/NOAA, Research Triangle Park, NC (United States)

    1996-12-31

    Biogenic emissions play a critical role in urban and regional air quality. For instance, biogenic emissions contribute upwards of 76% of the daily hydrocarbon emissions in the Atlanta, Georgia airshed. The Biogenic Emissions Inventory System-Version 2.0 (BEIS2) and the Biogenic Model for Emissions (BIOME) are two models that compute biogenic emissions estimates. BEIS2 is a FORTRAN-based system, and BIOME is an ARC/INFO{reg_sign} - and SAS{reg_sign}-based system. Although the technical formulations of the models are similar, the models produce different biogenic emissions estimates for what appear to be essentially the same inputs. The goals of our study are the following: (1) Determine why BIOME and BEIS2 produce different emissions estimates; (2) Attempt to understand the impacts that the differences have on the emissions estimates; (3) Reconcile the differences where possible; and (4) Present a framework for the use of BEIS2 and BIOME. In this study, we used the Coastal Oxidant Assessment for Southeast Texas (COAST) biogenics data which were supplied to us courtesy of the Texas Natural Resource Conservation Commission (TNRCC), and we extracted the BEIS2 data for the same domain. We compared the emissions estimates of the two models using their respective data sets BIOME Using TNRCC data and BEIS2 using BEIS2 data.

  12. We’re All in This Together | NIH MedlinePlus the Magazine

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  13. Achoo! Cold, Flu, or Something Else? | NIH MedlinePlus the Magazine

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  14. Psoriasis: On the Road to Discovery | NIH MedlinePlus the Magazine

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  15. Nick Jonas on Type 1 Diabetes | NIH MedlinePlus the Magazine

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  16. Asthma: What You Need to Know | NIH MedlinePlus the Magazine

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  17. Preventing Pregnancy with a Gel for Men? | NIH MedlinePlus the Magazine

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  18. Caregiving: It Takes a Village | NIH MedlinePlus the Magazine

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  19. Breathtaking: Managing a COPD Diagnosis | NIH MedlinePlus the Magazine

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  20. Understanding and preventing tick bites | NIH MedlinePlus the Magazine

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  1. Battling C. Difficile: Don’t Delay | NIH MedlinePlus the Magazine

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  2. From the lab - Exercise Key to Keeping Weight Off | NIH MedlinePlus the Magazine

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  3. From the lab - Can Potassium Help Your Heart? | NIH MedlinePlus the Magazine

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  4. Sickle Cell Disease: What You Should Know | NIH MedlinePlus the Magazine

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  5. A Journey with Mid-life Hearing Loss | NIH MedlinePlus the Magazine

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  6. Joint Replacement Surgery: What you Need to Know | NIH MedlinePlus the Magazine

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  7. The Future of Asthma Monitoring | NIH MedlinePlus the Magazine

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  8. Too ‘Stubborn’ to Give in to COPD | NIH MedlinePlus the Magazine

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  9. Cholesterol: The Good, the Bad, and the Unhealthy | NIH MedlinePlus the Magazine

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  10. Palliative Care: A Spectrum of Support | NIH MedlinePlus the Magazine

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  11. Confronting 9/11 Trauma from Childhood into Adulthood | NIH MedlinePlus the Magazine

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  12. Solving the Undiagnosed Disease Puzzle at NIH | NIH MedlinePlus the Magazine

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  13. Love and Life without Gluten | NIH MedlinePlus the Magazine

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  14. A Couple’s Caregiving Journey | NIH MedlinePlus the Magazine

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  15. Surgeon General Outlines Opioid Plan | NIH MedlinePlus the Magazine

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  16. From the lab - Testing Malaria-Resistant Mosquitoes | NIH MedlinePlus the Magazine

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  17. A Path to Hope for Sickle Cell Disease | NIH MedlinePlus the Magazine

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  18. Step Inside NIH’s Sickle Cell Branch | NIH MedlinePlus the Magazine

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  19. From the lab - Progress Against Zika | NIH MedlinePlus the Magazine

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  20. A Closer Look at Cancer Imaging Tools | NIH MedlinePlus the Magazine

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  1. Exploring the Celiac Disease Mystery | NIH MedlinePlus the Magazine

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  2. Beyond Pain Relief: Total Knee Replacement Surgery | NIH MedlinePlus the Magazine

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  3. TV Star Jim Parsons Shines Light on NIH Research | NIH MedlinePlus the Magazine

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  4. Advance Care Plan: A Checklist for the Future | NIH MedlinePlus the Magazine

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  5. Understanding Asthma from the Inside Out | NIH MedlinePlus the Magazine

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  6. Keys to Recovery after Knee Replacement Surgery | NIH MedlinePlus the Magazine

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  7. Fighting the Flu with a Universal Vaccine | NIH MedlinePlus the Magazine

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  8. Using incomplete citation data for MEDLINE results ranking.

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    Herskovic, Jorge R; Bernstam, Elmer V

    2005-01-01

    Information overload is a significant problem for modern medicine. Searching MEDLINE for common topics often retrieves more relevant documents than users can review. Therefore, we must identify documents that are not only relevant, but also important. Our system ranks articles using citation counts and the PageRank algorithm, incorporating data from the Science Citation Index. However, citation data is usually incomplete. Therefore, we explore the relationship between the quantity of citation information available to the system and the quality of the result ranking. Specifically, we test the ability of citation count and PageRank to identify "important articles" as defined by experts from large result sets with decreasing citation information. We found that PageRank performs better than simple citation counts, but both algorithms are surprisingly robust to information loss. We conclude that even an incomplete citation database is likely to be effective for importance ranking.

  9. Concluding remarks: overall impacts on biodiversity and future perspectives for conservation in the Pantanal biome.

    Science.gov (United States)

    Alho, C J R

    2011-04-01

    The Pantanal biome is characterised by seasonal flooding which determines specific ecosystem processes, with the occurrence of adapted plants and animals to the annual shrinking and expansion of habitats due to the seasonal hydrological regime. Biodiversity abundance varies during the dry and wet seasons. The Pantanal's biodiversity is a fundamental component of ecosystem services for human society, including nutrient cycling, fish production, ecotourism, carbon storage, flood control, among others, which are relevant to regional and global environmental consequences. The biome has been impacted by the conversion of natural vegetation into agricultural fields and pasture for cattle raising, with alteration and loss of natural habitats and biodiversity. Major negative impacts occur in uplands, with drastic deforestation of savanna vegetation, where main rivers feeding the Pantanal have their springs. This article discusses future needs and priorities for ecological research, in order to better understand the biome's natural system, to achieve conservation and sustainable use.

  10. Concluding remarks: overall impacts on biodiversity and future perspectives for conservation in the Pantanal biome

    Directory of Open Access Journals (Sweden)

    CJR. Alho

    Full Text Available The Pantanal biome is characterised by seasonal flooding which determines specific ecosystem processes, with the occurrence of adapted plants and animals to the annual shrinking and expansion of habitats due to the seasonal hydrological regime. Biodiversity abundance varies during the dry and wet seasons. The Pantanal's biodiversity is a fundamental component of ecosystem services for human society, including nutrient cycling, fish production, ecotourism, carbon storage, flood control, among others, which are relevant to regional and global environmental consequences. The biome has been impacted by the conversion of natural vegetation into agricultural fields and pasture for cattle raising, with alteration and loss of natural habitats and biodiversity. Major negative impacts occur in uplands, with drastic deforestation of savanna vegetation, where main rivers feeding the Pantanal have their springs. This article discusses future needs and priorities for ecological research, in order to better understand the biome's natural system, to achieve conservation and sustainable use.

  11. Friends of the National Library of Medicine, Welcome to NIH MedlinePlus, the magazine | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... Contents Dear Readers, WELCOME to NIH MedlinePlus , the magazine. The purpose of NIH MedlinePlus , the magazine, is to provide you with a FREE , trusted ... medical information. Published four times a year, the magazine showcases the National Institutes of Health's (NIH) latest ...

  12. BOREAS RSS-8 BIOME-BGC Model Simulations at Tower Flux Sites in 1994

    Science.gov (United States)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Kimball, John

    2000-01-01

    BIOME-BGC is a general ecosystem process model designed to simulate biogeochemical and hydrologic processes across multiple scales (Running and Hunt, 1993). In this investigation, BIOME-BGC was used to estimate daily water and carbon budgets for the BOREAS tower flux sites for 1994. Carbon variables estimated by the model include gross primary production (i.e., net photosynthesis), maintenance and heterotrophic respiration, net primary production, and net ecosystem carbon exchange. Hydrologic variables estimated by the model include snowcover, evaporation, transpiration, evapotranspiration, soil moisture, and outflow. The information provided by the investigation includes input initialization and model output files for various sites in tabular ASCII format.

  13. Where do the treeless tundra areas of northern highlands fit in the global biome system: toward an ecologically natural subdivision of the tundra biome.

    Science.gov (United States)

    Virtanen, Risto; Oksanen, Lauri; Oksanen, Tarja; Cohen, Juval; Forbes, Bruce C; Johansen, Bernt; Käyhkö, Jukka; Olofsson, Johan; Pulliainen, Jouni; Tømmervik, Hans

    2016-01-01

    According to some treatises, arctic and alpine sub-biomes are ecologically similar, whereas others find them highly dissimilar. Most peculiarly, large areas of northern tundra highlands fall outside of the two recent subdivisions of the tundra biome. We seek an ecologically natural resolution to this long-standing and far-reaching problem. We studied broad-scale patterns in climate and vegetation along the gradient from Siberian tundra via northernmost Fennoscandia to the alpine habitats of European middle-latitude mountains, as well as explored those patterns within Fennoscandian tundra based on climate-vegetation patterns obtained from a fine-scale vegetation map. Our analyses reveal that ecologically meaningful January-February snow and thermal conditions differ between different types of tundra. High precipitation and mild winter temperatures prevail on middle-latitude mountains, low precipitation and usually cold winters prevail on high-latitude tundra, and Scandinavian mountains show intermediate conditions. Similarly, heath-like plant communities differ clearly between middle latitude mountains (alpine) and high-latitude tundra vegetation, including its altitudinal extension on Scandinavian mountains. Conversely, high abundance of snowbeds and large differences in the composition of dwarf shrub heaths distinguish the Scandinavian mountain tundra from its counterparts in Russia and the north Fennoscandian inland. The European tundra areas fall into three ecologically rather homogeneous categories: the arctic tundra, the oroarctic tundra of northern heights and mountains, and the genuinely alpine tundra of middle-latitude mountains. Attempts to divide the tundra into two sub-biomes have resulted in major discrepancies and confusions, as the oroarctic areas are included in the arctic tundra in some biogeographic maps and in the alpine tundra in others. Our analyses based on climate and vegetation criteria thus seem to resolve the long-standing biome

  14. Carbon storage in permafrost and soils of the mammoth tundra-steppe biome: role in the global carbon budget

    Science.gov (United States)

    N.S. Zimov; S.A. Zimov; A.E. Zimova; G.M. Zimova; V.I. Chuprynin; F.S. Chapin

    2009-01-01

    During the Last Glacial Maximum (LGM), atmospheric CO2 concentration was 80-100 ppmv lower than in preindustrial times. At that time steppe-tundra was the most extensive biome on Earth. Some authors assume that C storage in that biome was very small, similar to today's deserts, and that the terrestrial carbon (C) reservoir increased at the...

  15. The Biological Observation Matrix (BIOM) format or: how I learned to stop worrying and love the ome-ome.

    Science.gov (United States)

    McDonald, Daniel; Clemente, Jose C; Kuczynski, Justin; Rideout, Jai Ram; Stombaugh, Jesse; Wendel, Doug; Wilke, Andreas; Huse, Susan; Hufnagle, John; Meyer, Folker; Knight, Rob; Caporaso, J Gregory

    2012-07-12

    We present the Biological Observation Matrix (BIOM, pronounced "biome") format: a JSON-based file format for representing arbitrary observation by sample contingency tables with associated sample and observation metadata. As the number of categories of comparative omics data types (collectively, the "ome-ome") grows rapidly, a general format to represent and archive this data will facilitate the interoperability of existing bioinformatics tools and future meta-analyses. The BIOM file format is supported by an independent open-source software project (the biom-format project), which initially contains Python objects that support the use and manipulation of BIOM data in Python programs, and is intended to be an open development effort where developers can submit implementations of these objects in other programming languages. The BIOM file format and the biom-format project are steps toward reducing the "bioinformatics bottleneck" that is currently being experienced in diverse areas of biological sciences, and will help us move toward the next phase of comparative omics where basic science is translated into clinical and environmental applications. The BIOM file format is currently recognized as an Earth Microbiome Project Standard, and as a Candidate Standard by the Genomic Standards Consortium.

  16. Large-scale impact of climate change vs. land-use change on future biome shifts in Latin America

    NARCIS (Netherlands)

    Boit, Alice; Sakschewski, Boris; Boysen, Lena; Cano-Crespo, Ana; Clement, Jan; Garcia-alaniz, Nashieli; Kok, Kasper; Kolb, Melanie; Langerwisch, Fanny; Rammig, Anja; Sachse, René; Eupen, van Michiel; Bloh, von Werner; Clara Zemp, Delphine; Thonicke, Kirsten

    2016-01-01

    Climate change and land-use change are two major drivers of biome shifts causing habitat and biodiversity loss. What is missing is a continental-scale future projection of the estimated relative impacts of both drivers on biome shifts over the course of this century. Here, we provide such a

  17. Spanish scientific output on Helicobacter pylori. A study through Medline.

    Science.gov (United States)

    Trapero-Marugán, M; Gisbert, J P; Pajares, J M

    2006-04-01

    to analyze scientific output from Spanish hospitals in relation to Helicobacter pylori infection. papers collected from the Medline database between January 1988 and December 2003 were selected. Our search strategy was: "Helicobacter pylori" [MeSH] AND ((Spain [AD] OR Espana [AD] OR Spanien [AD] OR Espagne [AD] OR Espanha [AD]) OR (Spanish [LA]) OR Spain). The following was analyzed: geographic area, Spanish or foreign publication, topic, and year of publication. Output and impact bibliometric markers were evaluated. in all, 691 papers were identified, of which 241 were excluded. Number of papers went from 2 in 1988 to 47 in 2002 and 13 in 2003. There were more reports in Spanish versus foreign journals (58 vs. 42%). In the first 5 years the areas with greater output were associated with diagnosis and microbiology (33 and 20%), whereas therapy was the predominating subject during the last 5 years (27%). Original papers were most common among publications (69%). Hospitals with highest output included La Princesa (24%) and Ramón y Cajal (17.6%) in Madrid, and Parc Taulí in Barcelona (6.4%). Mean impact factor progressively increased from 1.826 in 1988 to 2.142 in 2002 and 2.493 in 2003. the production and impact of documents published by Spanish scientists regarding H. pylori infection considerably increased during the past two decades.

  18. Water balance in paired watersheds with eucalyptus and degraded grassland in Pampa biome

    Science.gov (United States)

    Rangelands of the Pampa biome, which cover regions of Argentina, Uruguay and Brazil (176,496 km2 – 2.07% of Brazilian territory and 63% of Rio Grande do Sul State territory, southern region of Brazil) in South America (total area of 750,000 km2), are being substituted by crops and commercial eucalyp...

  19. Selection of native trees for intercropping with coffee in the Atlantic Rainforest biome

    NARCIS (Netherlands)

    Souza, de H.N.; Cardoso, I.M.; Fernandes, J.M.; Garcia, F.C.P.; Bonfim, V.R.; Santos, A.C.; Carvalho, A.F.; Mendonca, E.S.

    2010-01-01

    A challenge in establishing agroforestry systems is ensuring that farmers are interested in the tree species, and are aware of how to adequately manage these species. This challenge was tackled in the Atlantic Rainforest biome (Brazil), where a participatory trial with agroforestry coffee systems

  20. A new species of Andocaeculus (Acari, Caeculidae) from the Pampa biome, southern Brazil

    OpenAIRE

    Ana Paula Ott; Ricardo Ott

    2014-01-01

    A new caeculid species Andocaeculus caioi sp. nov. is described from Pampa biome in south Brazil. The species of this family are usually large and strong sclerotized mites with robust and spinulose legs I and II. Until now records of species for South America were known only from Chile and Argentina.

  1. Hantavirus pulmonary syndrome and rodent reservoirs in the savanna-like biome of Brazil's southeastern region.

    Science.gov (United States)

    Limongi, J E; Oliveira, R C; Guterres, A; Costa Neto, S F; Fernandes, J; Vicente, L H B; Coelho, M G; Ramos, V N; Ferreira, M S; Bonvicino, C R; D'Andrea, P S; Lemos, E R S

    2016-04-01

    This paper describes the diversity of rodent fauna in an area endemic for hantavirus cardiopulmonary syndrome (HCPS) in Brazil, the population dynamics and the relationship of rodents with hantavirus in the Cerrado (savanna-like) biome. Additionally, an analysis is made of the partial S segment sequences of the hantaviruses obtained from serologically confirmed human HCPS cases and from rodent specimens. Rodents were collected during four campaigns. Human serum samples were collected from suspected cases of HCPS at hospitals in the state of Minas Gerais. The samples antibody-reactive by ELISA were processed by RT-PCR. The PCR product was amplified and sequenced. Hantavirus was detected only in Necromys lasiurus, the wild rodent species most prevalent in the Cerrado biome (min-max: 50-83·7%). All the six human serum samples were hantavirus seropositive and five showed amplified PCR products. The analysis of the nucleotide sequences showed the circulation of a single genotype, the Araraquara hantavirus. The environmental changes that have occurred in the Cerrado biome in recent decades have favoured N. lasiurus in interspecific competition of habitats, thus increasing the risk of contact between humans and rodent species infected with hantavirus. Our data corroborate the definition of N. lasiurus as the main hantavirus reservoir in the Cerrado biome.

  2. Extreme precipitation patterns and reductions of terrestrial ecosystem production across biomes

    Science.gov (United States)

    Yongguang Zhang; M. Susan Moran; Mark A. Nearing; Guillermo E. Ponce Campos; Alfredo R. Huete; Anthony R. Buda; David D. Bosch; Stacey A. Gunter; Stanley G. Kitchen; W. Henry McNab; Jack A. Morgan; Mitchel P. McClaran; Diane S. Montoya; Debra P.C. Peters; Patrick J. Starks

    2013-01-01

    Precipitation regimes are predicted to shift to more extreme patterns that are characterized by more heavy rainfall events and longer dry intervals, yet their ecological impacts on vegetation production remain uncertain across biomes in natural climatic conditions. This in situ study investigated the effects of these climatic conditions on aboveground net primary...

  3. The Biome Project: Developing a Legitimate Parallel Curriculum for Physical Education and Life Sciences

    Science.gov (United States)

    Hastie, Peter Andrew

    2013-01-01

    The purpose of this article is to describe the outcomes of a parallel curriculum project between life sciences and physical education. Throughout a 6-week period, students in grades two through five became members of teams that represented different animal species and biomes, and concurrently participated in a season of gymnastics skills and…

  4. Guide to the literature on research in the grassland biome of South Africa

    CSIR Research Space (South Africa)

    Tainton, MN

    1984-12-01

    Full Text Available the development of an understanding of how these communities can best be managed to ensure their sustained producti¬vity, or indeed to increase their productivity. This publication serves to highlight the main work which has been undertaken in this biome...

  5. Remotely sensed vegetation phenology for describing and predicting the biomes of South Africa

    CSIR Research Space (South Africa)

    Wessels, Konrad J

    2011-02-01

    Full Text Available the distribution of the recently redefined biomes be predicted based on remotely sensed, phenology and productivity metrics? Ten-day, 1 km, NDVI AVHRR were analysed for the period 1985 to 2000. Phenological metrics such as start, end and length of the growing...

  6. Modeling Carbon and Water Budgets in the Lushi Basin with Biome-BGC

    Institute of Scientific and Technical Information of China (English)

    Dong Wenjuan; Qi Ye; Li Huimin; Zhou Dajie; Shi Duanhua; Sun Liying

    2005-01-01

    In this article, annual evapotranspiration (ET) and net primary productivity (NPP) of four types of vegetation were estimated for the Lushi basin,a subbasin of the Yellow River in China. These four vegetation types include: deciduous broadleaf forest,evergreen needle leaf forest, dwarf shrub and grass.Biome-BGC--a biogeochemical process model was used to calculate annual ET and NPP for each vegetation type in the study area from 1954 to 2000.Daily microclimate data of 47 years monitored by Lushi meteorological station was extrapolated to cover the basin using MT-CLIM, a mountain microclimate simulator. The output files of MTCLIM were used to feed Biome-BGC. We used average ecophysiological values of each type of vegetation supplied by Numerical Terradynamic Simulation Group (NTSG) in the University of Montana as input ecophysiological constants file.The estimates of daily NPP in early July and annual ET on these four biome groups were compared respectively with field measurements and other studies.Daily gross primary production (GPP) of evergreen needle leaf forest measurements were very dose to the output of Biome-BGC, but measurements of broadleaf forest and dwarf shrub were much smaller than the simulation result. Simulated annual ET and NPP had a significant correlation with precipitation,indicating precipitation is the major environmental factor affecting ET and NPP in the study area.Precipitation also is the key climatic factor for the interannual ET and NPP variations.

  7. Global negative vegetation feedback to climate warming responses of leaf litter decomposition rates in cold biomes.

    NARCIS (Netherlands)

    Cornelissen, J.H.C.; van Bodegom, P.M.; Aerts, R.; Gallaghan, T.V.; van Logtestijn, R.S.P; Alatalo, J.; Chapin, F.S. III; Gerdol, R.; Gudmundsson, J.; Gwynn-Jones, D.; Hartley, A.E.; Hik, D.S.; Hofgaard, A.; Jonsdottir, I.S.; Karlsson, S.; Klein, J.A.; Laundre, J.; Magnusson, B.; Michelsel, A.; Molau, U.; Onipchenko, V.G.; Quested, H.M.; Sandvik, S.M.; Schmidt, I.K.; Shaver, G.R.; Solhleim, B.; Soudzilovskaia, N.A.; Stenstrom, A.; Tolvanen, A.; Totland, O.; Wada, N.; Welker, J.M.; Zhao, X.; Team, M.O.L.

    2007-01-01

    Whether climate change will turn cold biomes from large long-term carbon sinks into sources is hotly debated because of the great potential for ecosystem-mediated feedbacks to global climate. Critical are the direction, magnitude and generality of climate responses of plant litter decomposition.

  8. The freezer defrosting: global warming and litter decomposition rates in cold biomes. Essay review.

    NARCIS (Netherlands)

    Aerts, R.

    2006-01-01

    1 Decomposition of plant litter, a key component of the global carbon budget, is hierarchically controlled by the triad: climate > litter quality > soil organisms. Given the sensitivity of decomposition to temperature, especially in cold biomes, it has been hypothesized that global warming will lead

  9. A reconstruction of Colombian biomes derived from modern pollen data along an altitude gradient

    NARCIS (Netherlands)

    Marchant, R.; Berrío, J.C.; Cleef, A.M.; Duivenvoorden, J.; Helmens, K.; Hooghiemstra, H.; Kuhry, P.; Melief, B.; Schreve-Brinkman, E.; Geel, van B.; Reenen, van G.; Hammen, van der T.

    2001-01-01

    Biomes are reconstructed in Colombia from modern (core-top) pollen data derived from 22 sites along an altitudinal gradient (2000–4100 m) that encompasses the tree line. The `biomization' methodology is described in a stepwise manner that details the reconstruction of vegetation along an altitudinal

  10. A reconstruction of Colombian biomes derived from modern pollen data along an altitude gradient.

    NARCIS (Netherlands)

    Marchant, R.A.; Behling, H.; Berrio Mogollon, J.C.; Cleef, A.M.; Duivenvoorden, J.F.; van Geel, B.; van der Hammen, T.; Hooghiemstra, H.; Kuhry, P.; Melief, B.M.; van Reenen, G.B.A.; Wille, M.

    2001-01-01

    Biomes are reconstructed in Colombia from modern (core-top) pollen data derived from twenty-two sites along an altitudinal gradient (2000 to 4100 m) that encompasses the tree line. The 'biomization' methodology is described in a stepwise manner that details the reconstruction of vegetation along an

  11. Pollen-based biome reconstructions for Colombia at 3000, 6000, 15 000 and 18 000 14C yr ago : Late Quaternary tropical vegetation dynamics

    NARCIS (Netherlands)

    Marchant, R.; Behling, H.; Berrío, J.C.; Cleef, A.M.; Duivenvoorden, J.; Hooghiemstra, H.; Kuhry, P.; Melief, B.; Schreve-Brinkman, E.; Geel, van B.; Hammen, van der T.; Reenen, van G.

    2002-01-01

    Colombian biomes are reconstructed at 45 sites from the modern period extending to the Last Glacial Maximum (LGM). The basis for our reconstruction is pollen data assigned to plant functional types and biomes at six 3000-yr intervals. A reconstruction of modern biomes is used to check the treatment

  12. Estimating 40 years of nitrogen deposition in global biomes using the SCIAMACHY NO2 column

    Science.gov (United States)

    Lu, Xuehe; Zhang, Xiuying; Liu, Jinxun; Jin, Jiaxin

    2016-01-01

    Owing to human activity, global nitrogen (N) cycles have been altered. In the past 100 years, global N deposition has increased. Currently, the monitoring and estimating of N deposition and the evaluation of its effects on global carbon budgets are the focus of many researchers. NO2 columns retrieved by space-borne sensors provide us with a new way of exploring global N cycles and these have the ability to estimate N deposition. However, the time range limitation of NO2 columns makes the estimation of long timescale N deposition difficult. In this study we used ground-based NOx emission data to expand the density of NO2columns, and 40 years of N deposition (1970–2009) was inverted using the multivariate linear model with expanded NO2 columns. The dynamic of N deposition was examined in both global and biome scales. The results show that the average N deposition was 0.34 g N m–2 year–1 in the 2000s, which was an increase of 38.4% compared with the 1970s’. The total N deposition in different biomes is unbalanced. N deposition is only 38.0% of the global total in forest biomes; this is made up of 25.9%, 11.3, and 0.7% in tropical, temperate, and boreal forests, respectively. As N-limited biomes, there was little increase of N deposition in boreal forests. However, N deposition has increased by a total of 59.6% in tropical forests and croplands, which are N-rich biomes. Such characteristics may influence the effects on global carbon budgets.

  13. Forest carbon emissions from cropland expansion in the Brazilian Cerrado biome

    Science.gov (United States)

    Noojipady, Praveen; Morton, C. Douglas; Macedo, N. Marcia; Victoria, C. Daniel; Huang, Chengquan; Gibbs, K. Holly; Edson Bolfe, L.

    2017-02-01

    Land use, land use change, and forestry accounted for two-thirds of Brazil’s greenhouse gas emissions profile in 2005. Amazon deforestation has declined by more than 80% over the past decade, yet Brazil’s forests extend beyond the Amazon biome. Rapid expansion of cropland in the neighboring Cerrado biome has the potential to undermine climate mitigation efforts if emissions from dry forest and woodland conversion negate some of the benefits of avoided Amazon deforestation. Here, we used satellite data on cropland expansion, forest cover, and vegetation carbon stocks to estimate annual gross forest carbon emissions from cropland expansion in the Cerrado biome. Nearly half of the Cerrado met Brazil’s definition of forest cover in 2000 (≥0.5 ha with ≥10% canopy cover). In areas of established crop production, conversion of both forest and non-forest Cerrado formations for cropland declined during 2003-2013. However, forest carbon emissions from cropland expansion increased over the past decade in Matopiba, a new frontier of agricultural production that includes portions of Maranhão, Tocantins, Piauí, and Bahia states. Gross carbon emissions from cropland expansion in the Cerrado averaged 16.28 Tg C yr-1 between 2003 and 2013, with forest-to-cropland conversion accounting for 29% of emissions. The fraction of forest carbon emissions from Matopiba was much higher; between 2010-2013, large-scale cropland conversion in Matopiba contributed 45% of total Cerrado forest carbon emissions. Carbon emissions from Cerrado-to-cropland transitions offset 5%-7% of the avoided emissions from reduced Amazon deforestation rates during 2011-2013. Comprehensive national estimates of forest carbon fluxes, including all biomes, are critical to detect cross-biome leakage within countries and achieve climate mitigation targets to reduce emissions from land use, land use change, and forestry.

  14. Temporal Changes in Coupled Vegetation Phenology and Productivity are Biome-Specific in the Northern Hemisphere

    Directory of Open Access Journals (Sweden)

    Lanhui Wang

    2017-12-01

    Full Text Available Global warming has greatly stimulated vegetation growth through both extending the growing season and promoting photosynthesis in the Northern Hemisphere (NH. Analyzing the combined dynamics of such trends can potentially improve our current understanding on changes in vegetation functioning and the complex relationship between anthropogenic and climatic drivers. This study aims to analyze the relationships (long-term trends and correlations of length of vegetation growing season (LOS and vegetation productivity assessed by the growing season NDVI integral (GSI in the NH (>30°N to study any dependency of major biomes that are characterized by different imprint from anthropogenic influence. Spatial patterns of converging/diverging trends in LOS and GSI and temporal changes in the coupling between LOS and GSI are analyzed for major biomes at hemispheric and continental scales from the third generation Global Inventory Monitoring and Modeling Studies (GIMMS Normalized Difference Vegetation Index (NDVI dataset for a 32-year period (1982–2013. A quarter area of the NH is covered by converging trends (consistent significant trends in LOS and GSI, whereas diverging trends (opposing significant trends in LOS and GSI cover about 6% of the region. Diverging trends are observed mainly in high latitudes and arid/semi-arid areas of non-forest biomes (shrublands, savannas, and grasslands, whereas forest biomes and croplands are primarily characterized by converging trends. The study shows spatially-distinct and biome-specific patterns between the continental land masses of Eurasia (EA and North America (NA. Finally, areas of high positive correlation between LOS and GSI showed to increase during the period of analysis, with areas of significant positive trends in correlation being more widespread in NA as compared to EA. The temporal changes in the coupled vegetation phenology and productivity suggest complex relationships and interactions that are induced

  15. Aura-biomes are present in the water layer above coral reef benthic macro-organisms.

    Science.gov (United States)

    Walsh, Kevin; Haggerty, J Matthew; Doane, Michael P; Hansen, John J; Morris, Megan M; Moreira, Ana Paula B; de Oliveira, Louisi; Leomil, Luciana; Garcia, Gizele D; Thompson, Fabiano; Dinsdale, Elizabeth A

    2017-01-01

    As coral reef habitats decline worldwide, some reefs are transitioning from coral- to algal-dominated benthos with the exact cause for this shift remaining elusive. Increases in the abundance of microbes in the water column has been correlated with an increase in coral disease and reduction in coral cover. Here we investigated how multiple reef organisms influence microbial communities in the surrounding water column. Our study consisted of a field assessment of microbial communities above replicate patches dominated by a single macro-organism. Metagenomes were constructed from 20 L of water above distinct macro-organisms, including (1) the coral Mussismilia braziliensis , (2) fleshy macroalgae ( Stypopodium , Dictota and Canistrocarpus ), (3) turf algae, and (4) the zoanthid Palythoa caribaeorum and were compared to the water microbes collected 3 m above the reef. Microbial genera and functional potential were annotated using MG-RAST and showed that the dominant benthic macro-organisms influence the taxa and functions of microbes in the water column surrounding them, developing a specific "aura-biome". The coral aura-biome reflected the open water column, and was associated with Synechococcus and functions suggesting oligotrophic growth, while the fleshy macroalgae aura-biome was associated with Ruegeria , Pseudomonas, and microbial functions suggesting low oxygen conditions. The turf algae aura-biome was associated with Vibrio, Flavobacterium, and functions suggesting pathogenic activity, while zoanthids were associated with Alteromonas and functions suggesting a stressful environment. Because each benthic organism has a distinct aura-biome, a change in benthic cover will change the microbial community of the water, which may lead to either the stimulation or suppression of the recruitment of benthic organisms.

  16. Forgotten forests - issues and prospects in biome mapping using Seasonally Dry Tropical Forests as a case study

    Science.gov (United States)

    2011-01-01

    Background South America is one of the most species diverse continents in the world. Within South America diversity is not distributed evenly at both local and continental scales and this has led to the recognition of various areas with unique species assemblages. Several schemes currently exist which divide the continental-level diversity into large species assemblages referred to as biomes. Here we review five currently available biome maps for South America, including the WWF Ecoregions, the Americas basemap, the Land Cover Map of South America, Morrone's Biogeographic regions of Latin America, and the Ecological Systems Map. The comparison is performed through a case study on the Seasonally Dry Tropical Forest (SDTF) biome using herbarium data of habitat specialist species. Results Current biome maps of South America perform poorly in depicting SDTF distribution. The poor performance of the maps can be attributed to two main factors: (1) poor spatial resolution, and (2) poor biome delimitation. Poor spatial resolution strongly limits the use of some of the maps in GIS applications, especially for areas with heterogeneous landscape such as the Andes. Whilst the Land Cover Map did not suffer from poor spatial resolution, it showed poor delimitation of biomes. The results highlight that delimiting structurally heterogeneous vegetation is difficult based on remote sensed data alone. A new refined working map of South American SDTF biome is proposed, derived using the Biome Distribution Modelling (BDM) approach where georeferenced herbarium data is used in conjunction with bioclimatic data. Conclusions Georeferenced specimen data play potentially an important role in biome mapping. Our study shows that herbarium data could be used as a way of ground-truthing biome maps in silico. The results also illustrate that herbarium data can be used to model vegetation maps through predictive modelling. The BDM approach is a promising new method in biome mapping, and could be

  17. Forgotten forests--issues and prospects in biome mapping using Seasonally Dry Tropical Forests as a case study.

    Science.gov (United States)

    Särkinen, Tiina; Iganci, João R V; Linares-Palomino, Reynaldo; Simon, Marcelo F; Prado, Darién E

    2011-11-24

    South America is one of the most species diverse continents in the world. Within South America diversity is not distributed evenly at both local and continental scales and this has led to the recognition of various areas with unique species assemblages. Several schemes currently exist which divide the continental-level diversity into large species assemblages referred to as biomes. Here we review five currently available biome maps for South America, including the WWF Ecoregions, the Americas basemap, the Land Cover Map of South America, Morrone's Biogeographic regions of Latin America, and the Ecological Systems Map. The comparison is performed through a case study on the Seasonally Dry Tropical Forest (SDTF) biome using herbarium data of habitat specialist species. Current biome maps of South America perform poorly in depicting SDTF distribution. The poor performance of the maps can be attributed to two main factors: (1) poor spatial resolution, and (2) poor biome delimitation. Poor spatial resolution strongly limits the use of some of the maps in GIS applications, especially for areas with heterogeneous landscape such as the Andes. Whilst the Land Cover Map did not suffer from poor spatial resolution, it showed poor delimitation of biomes. The results highlight that delimiting structurally heterogeneous vegetation is difficult based on remote sensed data alone. A new refined working map of South American SDTF biome is proposed, derived using the Biome Distribution Modelling (BDM) approach where georeferenced herbarium data is used in conjunction with bioclimatic data. Georeferenced specimen data play potentially an important role in biome mapping. Our study shows that herbarium data could be used as a way of ground-truthing biome maps in silico. The results also illustrate that herbarium data can be used to model vegetation maps through predictive modelling. The BDM approach is a promising new method in biome mapping, and could be particularly useful for mapping

  18. Forgotten forests - issues and prospects in biome mapping using Seasonally Dry Tropical Forests as a case study

    Directory of Open Access Journals (Sweden)

    Särkinen Tiina

    2011-11-01

    Full Text Available Abstract Background South America is one of the most species diverse continents in the world. Within South America diversity is not distributed evenly at both local and continental scales and this has led to the recognition of various areas with unique species assemblages. Several schemes currently exist which divide the continental-level diversity into large species assemblages referred to as biomes. Here we review five currently available biome maps for South America, including the WWF Ecoregions, the Americas basemap, the Land Cover Map of South America, Morrone's Biogeographic regions of Latin America, and the Ecological Systems Map. The comparison is performed through a case study on the Seasonally Dry Tropical Forest (SDTF biome using herbarium data of habitat specialist species. Results Current biome maps of South America perform poorly in depicting SDTF distribution. The poor performance of the maps can be attributed to two main factors: (1 poor spatial resolution, and (2 poor biome delimitation. Poor spatial resolution strongly limits the use of some of the maps in GIS applications, especially for areas with heterogeneous landscape such as the Andes. Whilst the Land Cover Map did not suffer from poor spatial resolution, it showed poor delimitation of biomes. The results highlight that delimiting structurally heterogeneous vegetation is difficult based on remote sensed data alone. A new refined working map of South American SDTF biome is proposed, derived using the Biome Distribution Modelling (BDM approach where georeferenced herbarium data is used in conjunction with bioclimatic data. Conclusions Georeferenced specimen data play potentially an important role in biome mapping. Our study shows that herbarium data could be used as a way of ground-truthing biome maps in silico. The results also illustrate that herbarium data can be used to model vegetation maps through predictive modelling. The BDM approach is a promising new method in

  19. Invasion of a Legume Ecosystem Engineer in a Cold Biome Alters Plant Biodiversity

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    Vanessa M. S. Vetter

    2018-06-01

    Full Text Available Plant ecosystem engineers are widely used to combat land degradation. However, the ability of those plants to modulate limiting abiotic and biotic resources of other species can cause damage to ecosystems in which they become invasive. Here, we use Lupinus nootkatensis as example to estimate and project the hazardous potential of nitrogen fixing herbaceous plants in a sub-polar oceanic climate. L. nootkatensis was introduced to Iceland in the 1940s to address erosion problems and foster reforestation, but subsequently became a high-latitude invader. In a local field survey, we quantified the impact of L. nootkatensis invasion at three different cover levels (0, 10–50, and 51–100% upon native plant diversity, richness, and community composition of heath-, wood-, and grasslands using a pairwise comparison design and comparisons of means. Afterward, we scaled impacts up to the ecosystem and landscape level by relating occurrences of L. nootkatensis to environmental and human-mediated variables across Iceland using a species distribution model. Plant diversity was significantly deteriorated under high lupine cover levels of the heath- and woodland, but not in the grassland. Plant species richness of the most diverse habitat, the heathland, linearly decreased with lupine cover level. The abundance of small rosettes, cushion plants, orchids, and small woody long-lived plants of the heath declined with invader presence, while the abundance of late successional species and widespread nitrophilous ruderals in wood- and grasslands increased. Distribution modeling revealed 13.3% of Iceland’s land surface area to be suitable lupine habitat. Until 2061–2080, this area will more than double and expand significantly into the Central Highlands due to human mediation and increasingly favorable climatic conditions. Species-rich habitats showed a loss of plant species diversity and richness as well as a change in community composition even in low lupine

  20. The Biological Observation Matrix (BIOM format or: how I learned to stop worrying and love the ome-ome

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    McDonald Daniel

    2012-07-01

    Full Text Available Abstract Background We present the Biological Observation Matrix (BIOM, pronounced “biome” format: a JSON-based file format for representing arbitrary observation by sample contingency tables with associated sample and observation metadata. As the number of categories of comparative omics data types (collectively, the “ome-ome” grows rapidly, a general format to represent and archive this data will facilitate the interoperability of existing bioinformatics tools and future meta-analyses. Findings The BIOM file format is supported by an independent open-source software project (the biom-format project, which initially contains Python objects that support the use and manipulation of BIOM data in Python programs, and is intended to be an open development effort where developers can submit implementations of these objects in other programming languages. Conclusions The BIOM file format and the biom-format project are steps toward reducing the “bioinformatics bottleneck” that is currently being experienced in diverse areas of biological sciences, and will help us move toward the next phase of comparative omics where basic science is translated into clinical and environmental applications. The BIOM file format is currently recognized as an Earth Microbiome Project Standard, and as a Candidate Standard by the Genomic Standards Consortium.

  1. Future changes in South American biomass distributions, biome distributions and plant trait spectra is dependent on applied atmospheric forcings.

    Science.gov (United States)

    Langan, Liam; Scheiter, Simon; Higgins, Steven

    2017-04-01

    It remains poorly understood why the position of the forest-savanna biome boundary, in a domain defined by precipitation and temperature, differs in South America, Africa and Australia. Process based Dynamic Global Vegetation Models (DGVMs) are a valuable tool to investigate the determinants of vegetation distributions, however, many DGVMs fail to predict the spatial distribution or indeed presence of the South American savanna biome. Evidence suggests fire plays a significant role in mediating forest-savanna biome boundaries, however, fire alone appear to be insufficient to predict these boundaries in South America. We hypothesize that interactions between precipitation, constraints on tree rooting depth and fire, affect the probability of savanna occurrence and the position of the savanna-forest boundary. We tested our hypotheses at tropical forest and savanna sites in Brazil and Venezuela using a novel DGVM, aDGVM2, which allows plant trait spectra, constrained by trade-offs between traits, to evolve in response to abiotic and biotic conditions. Plant hydraulics is represented by the cohesion-tension theory, this allowed us to explore how soil and plant hydraulics control biome distributions and plant traits. The resulting community trait distributions are emergent properties of model dynamics. We showed that across much of South America the biome state is not determined by climate alone. Interactions between tree rooting depth, fire and precipitation affected the probability of observing a given biome state and the emergent traits of plant communities. Simulations where plant rooting depth varied in space provided the best match to satellite derived biomass estimates and generated biome distributions that reproduced contemporary biome maps well. Future projections showed that biomass distributions, biome distributions and plant trait spectra will change, however, the magnitude of these changes are highly dependent on the applied atmospheric forcings.

  2. The medline UK filter: development and validation of a geographic search filter to retrieve research about the UK from OVID medline.

    Science.gov (United States)

    Ayiku, Lynda; Levay, Paul; Hudson, Tom; Craven, Jenny; Barrett, Elizabeth; Finnegan, Amy; Adams, Rachel

    2017-07-13

    A validated geographic search filter for the retrieval of research about the United Kingdom (UK) from bibliographic databases had not previously been published. To develop and validate a geographic search filter to retrieve research about the UK from OVID medline with high recall and precision. Three gold standard sets of references were generated using the relative recall method. The sets contained references to studies about the UK which had informed National Institute for Health and Care Excellence (NICE) guidance. The first and second sets were used to develop and refine the medline UK filter. The third set was used to validate the filter. Recall, precision and number-needed-to-read (NNR) were calculated using a case study. The validated medline UK filter demonstrated 87.6% relative recall against the third gold standard set. In the case study, the medline UK filter demonstrated 100% recall, 11.4% precision and a NNR of nine. A validated geographic search filter to retrieve research about the UK with high recall and precision has been developed. The medline UK filter can be applied to systematic literature searches in OVID medline for topics with a UK focus. © 2017 Crown copyright. Health Information and Libraries Journal © 2017 Health Libraries GroupThis article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

  3. Remote Sensing of the Urban Heat Island Effect Across Biomes in the Continental USA

    Science.gov (United States)

    Imhoff, Marc L.; Zhang, Ping; Wolfe, Robert E.; Bounoua, Lahouari

    2010-01-01

    Impervious surface area (ISA) from the Landsat TM-based NLCD 2001 dataset and land surface temperature (LST) from MODIS averaged over three annual cycles (2003-2005) are used in a spatial analysis to assess the urban heat island (UHI) skin temperature amplitude and its relationship to development intensity, size, and ecological setting for 38 of the most populous cities in the continental United States. Development intensity zones based on %ISA are defined for each urban area emanating outward from the urban core to the nonurban rural areas nearby and used to stratify sampling for land surface temperatures and NDVI. Sampling is further constrained by biome and elevation to insure objective intercomparisons between zones and between cities in different biomes permitting the definition of hierarchically ordered zones that are consistent across urban areas in different ecological setting and across scales. We find that ecological context significantly influences the amplitude of summer daytime UHI (urban-rural temperature difference) the largest (8 C average) observed for cities built in biomes dominated by temperate broadleaf and mixed forest. For all cities combined, ISA is the primary driver for increase in temperature explaining 70% of the total variance in LST. On a yearly average, urban areas are substantially warmer than the non-urban fringe by 2.9 C, except for urban areas in biomes with arid and semiarid climates. The average amplitude of the UHI is remarkably asymmetric with a 4.3 C temperature difference in summer and only 1.3 C in winter. In desert environments, the LST's response to ISA presents an uncharacteristic "U-shaped" horizontal gradient decreasing from the urban core to the outskirts of the city and then increasing again in the suburban to the rural zones. UHI's calculated for these cities point to a possible heat sink effect. These observational results show that the urban heat island amplitude both increases with city size and is seasonally

  4. Microbial Diversity in Cerrado Biome (Neotropical Savanna Soils.

    Directory of Open Access Journals (Sweden)

    Alinne Pereira de Castro

    Full Text Available The Cerrado, the largest savanna region in South America, is located in central Brazil. Cerrado physiognomies, which range from savanna grasslands to forest formations, combined with the highly weathered, acidic clay Cerrado soils form a unique ecoregion. In this study, high-throughput sequencing of ribosomal RNA genes was combined with shotgun metagenomic analysis to explore the taxonomic composition and potential functions of soil microbial communities in four different vegetation physiognomies during both dry and rainy seasons. Our results showed that changes in bacterial, archaeal, and fungal community structures in cerrado denso, cerrado sensu stricto, campo sujo, and gallery forest soils strongly correlated with seasonal patterns of soil water uptake. The relative abundance of AD3, WPS-2, Planctomycetes, Thermoprotei, and Glomeromycota typically decreased in the rainy season, whereas the relative abundance of Proteobacteria and Ascomycota increased. In addition, analysis of shotgun metagenomic data revealed a significant increase in the relative abundance of genes associated with iron acquisition and metabolism, dormancy, and sporulation during the dry season, and an increase in the relative abundance of genes related to respiration and DNA and protein metabolism during the rainy season. These gene functional categories are associated with adaptation to water stress. Our results further the understanding of how tropical savanna soil microbial communities may be influenced by vegetation covering and temporal variations in soil moisture.

  5. Estimation of Carbon Flux of Forest Ecosystem over Qilian Mountains by BIOME-BGC Model

    Science.gov (United States)

    Yan, Min; Tian, Xin; Li, Zengyuan; Chen, Erxue; Li, Chunmei

    2014-11-01

    The gross primary production (GPP) and net ecosystem exchange (NEE) are important indicators for carbon fluxes. This study aims at evaluating the forest GPP and NEE over the Qilian Mountains using meteorological, remotely sensed and other ancillary data at large scale. To realize this, the widely used ecological-process-based model, Biome-BGC, and remote-sensing-based model, MODIS GPP algorithm, were selected for the simulation of the forest carbon fluxes. The combination of these two models was based on calibrating the Biome-BGC by the optimized MODIS GPP algorithm. The simulated GPP and NEE values were evaluated against the eddy covariance observed GPPs and NEEs, and the well agreements have been reached, with R2=0.76, 0.67 respectively.

  6. Candidatus Rickettsia andeanae, a spotted fever group agent infecting Amblyomma parvum ticks in two Brazilian biomes

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    Fernanda Aparecida Nieri-Bastos

    2014-04-01

    Full Text Available Adult ticks of the species Amblyomma parvum were collected from the vegetation in the Pantanal biome (state of Mato Grosso do Sul and from horses in the Cerrado biome (state of Piauí in Brazil. The ticks were individually tested for rickettsial infection via polymerase chain reaction (PCR targeting three rickettsial genes, gltA, ompA and ompB. Overall, 63.5% (40/63 and 66.7% (2/3 of A. parvum ticks from Pantanal and Cerrado, respectively, contained rickettsial DNA, which were all confirmed by DNA sequencing to be 100% identical to the corresponding fragments of the gltA, ompA and ompB genes of Candidatus Rickettsia andeanae. This report is the first to describe Ca. R. andeanae in Brazil.

  7. MedlinePlus Connect: Linking Patient Portals and Electronic Health Records to Health Information

    Science.gov (United States)

    ... Here: Home → MedlinePlus Connect URL of this page: https://medlineplus.gov/connect/overview.html MedlinePlus Connect Linking ... will change.) Old URLs New URLs Web Application https://apps.nlm.nih.gov/medlineplus/services/mpconnect.cfm? ...

  8. A hierarchical analysis of terrestrial ecosystem model Biome-BGC: Equilibrium analysis and model calibration

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, Peter E [ORNL; Wang, Weile [ORNL; Law, Beverly E. [Oregon State University; Nemani, Ramakrishna R [NASA Ames Research Center

    2009-01-01

    The increasing complexity of ecosystem models represents a major difficulty in tuning model parameters and analyzing simulated results. To address this problem, this study develops a hierarchical scheme that simplifies the Biome-BGC model into three functionally cascaded tiers and analyzes them sequentially. The first-tier model focuses on leaf-level ecophysiological processes; it simulates evapotranspiration and photosynthesis with prescribed leaf area index (LAI). The restriction on LAI is then lifted in the following two model tiers, which analyze how carbon and nitrogen is cycled at the whole-plant level (the second tier) and in all litter/soil pools (the third tier) to dynamically support the prescribed canopy. In particular, this study analyzes the steady state of these two model tiers by a set of equilibrium equations that are derived from Biome-BGC algorithms and are based on the principle of mass balance. Instead of spinning-up the model for thousands of climate years, these equations are able to estimate carbon/nitrogen stocks and fluxes of the target (steady-state) ecosystem directly from the results obtained by the first-tier model. The model hierarchy is examined with model experiments at four AmeriFlux sites. The results indicate that the proposed scheme can effectively calibrate Biome-BGC to simulate observed fluxes of evapotranspiration and photosynthesis; and the carbon/nitrogen stocks estimated by the equilibrium analysis approach are highly consistent with the results of model simulations. Therefore, the scheme developed in this study may serve as a practical guide to calibrate/analyze Biome-BGC; it also provides an efficient way to solve the problem of model spin-up, especially for applications over large regions. The same methodology may help analyze other similar ecosystem models as well.

  9. Ecological consequences of the expansion of N2-fixing plants in cold biomes

    Science.gov (United States)

    Hiltbrunner, Erika; Aerts, Rien; Bühlmann, Tobias; Huss-Danell, Kerstin; Magnusson, Borgthor; Myrold, David D.; Reed, Sasha C.; Sigurdsson, Bjarni D.; Körner, Christian

    2014-01-01

    Research in warm-climate biomes has shown that invasion by symbiotic dinitrogen (N2)-fixing plants can transform ecosystems in ways analogous to the transformations observed as a consequence of anthropogenic, atmospheric nitrogen (N) deposition: declines in biodiversity, soil acidification, and alterations to carbon and nutrient cycling, including increased N losses through nitrate leaching and emissions of the powerful greenhouse gas nitrous oxide (N2O). Here, we used literature review and case study approaches to assess the evidence for similar transformations in cold-climate ecosystems of the boreal, subarctic and upper montane-temperate life zones. Our assessment focuses on the plant genera Lupinus and Alnus, which have become invasive largely as a consequence of deliberate introductions and/or reduced land management. These cold biomes are commonly located in remote areas with low anthropogenic N inputs, and the environmental impacts of N2-fixer invasion appear to be as severe as those from anthropogenic N deposition in highly N polluted areas. Hence, inputs of N from N2 fixation can affect ecosystems as dramatically or even more strongly than N inputs from atmospheric deposition, and biomes in cold climates represent no exception with regard to the risk of being invaded by N2-fixing species. In particular, the cold biomes studied here show both a strong potential to be transformed by N2-fixing plants and a rapid subsequent saturation in the ecosystem’s capacity to retain N. Therefore, analogous to increases in N deposition, N2-fixing plant invasions must be deemed significant threats to biodiversity and to environmental quality.

  10. Reply: “Use of BIOME-BGC to simulate Mediterranean forest carbon stocks”

    OpenAIRE

    Maselli F; Salvati R; Barbati A; Chirici G; Chiesi M

    2011-01-01

    The current note responds to the critical contribution of Dr. Eastaugh on Chiesi et al. (Chiesi et al. 2011). That paper did not aim at applying BIOME-BGC to simulate stand growth, which requires a thorough modification of the model functions. In contrast, only a parameter setting was changed in order to adjust the predicted carbon storages during the simulation of quasi-equilibrium conditions. The adjustment was calibrated on volume statistics derived from the Tuscany forest inventory and is...

  11. Record of the Buff-fronted Owl (Aegolius harrisii in the Pampa Biome, southern Brazil

    Directory of Open Access Journals (Sweden)

    Marluci Müller Rebelato

    2011-02-01

    Full Text Available We present the second record of the Buff-fronted Owl (Aegolius harrisii in the Pampa Biome, South Brazil. On 17 January 2010 an adult male was found dead at the roadside along the BR-290, São Gabriel municipality, center-east of Rio Grande do Sul state. The specimen probably collided with a car when using the area for foraging. The record reported here agrees with the suggestion that A. harrisii can use disturbed and open areas.

  12. Software quality assurance and software safety in the Biomed Control System

    International Nuclear Information System (INIS)

    Singh, R.P.; Chu, W.T.; Ludewigt, B.A.; Marks, K.M.; Nyman, M.A.; Renner, T.R.; Stradtner, R.

    1989-01-01

    The Biomed Control System is a hardware/software system used for the delivery, measurement and monitoring of heavy-ion beams in the patient treatment and biology experiment rooms in the Bevalac at the Lawrence Berkeley Laboratory (LBL). This paper describes some aspects of this system including historical background philosophy, configuration management, hardware features that facilitate software testing, software testing procedures, the release of new software quality assurance, safety and operator monitoring. 3 refs

  13. Aura-biomes are present in the water layer above coral reef benthic macro-organisms

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    Kevin Walsh

    2017-08-01

    Full Text Available As coral reef habitats decline worldwide, some reefs are transitioning from coral- to algal-dominated benthos with the exact cause for this shift remaining elusive. Increases in the abundance of microbes in the water column has been correlated with an increase in coral disease and reduction in coral cover. Here we investigated how multiple reef organisms influence microbial communities in the surrounding water column. Our study consisted of a field assessment of microbial communities above replicate patches dominated by a single macro-organism. Metagenomes were constructed from 20 L of water above distinct macro-organisms, including (1 the coral Mussismilia braziliensis, (2 fleshy macroalgae (Stypopodium, Dictota and Canistrocarpus, (3 turf algae, and (4 the zoanthid Palythoa caribaeorum and were compared to the water microbes collected 3 m above the reef. Microbial genera and functional potential were annotated using MG-RAST and showed that the dominant benthic macro-organisms influence the taxa and functions of microbes in the water column surrounding them, developing a specific “aura-biome”. The coral aura-biome reflected the open water column, and was associated with Synechococcus and functions suggesting oligotrophic growth, while the fleshy macroalgae aura-biome was associated with Ruegeria, Pseudomonas, and microbial functions suggesting low oxygen conditions. The turf algae aura-biome was associated with Vibrio, Flavobacterium, and functions suggesting pathogenic activity, while zoanthids were associated with Alteromonas and functions suggesting a stressful environment. Because each benthic organism has a distinct aura-biome, a change in benthic cover will change the microbial community of the water, which may lead to either the stimulation or suppression of the recruitment of benthic organisms.

  14. Genetic diversity of bats coronaviruses in the Atlantic Forest hotspot biome, Brazil.

    Science.gov (United States)

    Góes, Luiz Gustavo Bentim; Campos, Angélica Cristine de Almeida; Carvalho, Cristiano de; Ambar, Guilherme; Queiroz, Luzia Helena; Cruz-Neto, Ariovaldo Pereira; Munir, Muhammad; Durigon, Edison Luiz

    2016-10-01

    Bats are notorious reservoirs of genetically-diverse and high-profile pathogens, and are playing crucial roles in the emergence and re-emergence of viruses, both in human and in animals. In this report, we identified and characterized previously unknown and diverse genetic clusters of bat coronaviruses in the Atlantic Forest Biome, Brazil. These results highlight the virus richness of bats and their possible roles in the public health. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Federal Conservation Units in Brazil: The Situation of Biomes and Regions

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    Eduardo Pacca Luna Mattar

    2018-03-01

    Full Text Available ABSTRACT Federal conservation units (FCU are areas legally established by the government, in order to meet the needs of protection and sustainable exploitation of biodiversity. A way to ensure the efficiency of public management is to systematize data. Therefore, the present study grouped and analyzed public data about FCU. Brazil has 309 federal conservation units, which represent 9.06% of the national territory and 45305 residents households. The Northern Region covers 84.80% of these families and 79.20% of its area belongs to FCU. The Amazônia biome has 14.57% of its territory occupied by FCU; on the other hand, Pantanal has only 0.98% of its area protected. There is a higher concentration of public agents in the FCU of the Southeastern region and in the Mata Atlântica biome. The analysis of this information reveals significant differences between the biomes and the federation units, a fact that reflects the importance of the organization of public data.

  16. Convergence in the temperature response of leaf respiration across biomes and plant functional types.

    Science.gov (United States)

    Heskel, Mary A; O'Sullivan, Odhran S; Reich, Peter B; Tjoelker, Mark G; Weerasinghe, Lasantha K; Penillard, Aurore; Egerton, John J G; Creek, Danielle; Bloomfield, Keith J; Xiang, Jen; Sinca, Felipe; Stangl, Zsofia R; Martinez-de la Torre, Alberto; Griffin, Kevin L; Huntingford, Chris; Hurry, Vaughan; Meir, Patrick; Turnbull, Matthew H; Atkin, Owen K

    2016-04-05

    Plant respiration constitutes a massive carbon flux to the atmosphere, and a major control on the evolution of the global carbon cycle. It therefore has the potential to modulate levels of climate change due to the human burning of fossil fuels. Neither current physiological nor terrestrial biosphere models adequately describe its short-term temperature response, and even minor differences in the shape of the response curve can significantly impact estimates of ecosystem carbon release and/or storage. Given this, it is critical to establish whether there are predictable patterns in the shape of the respiration-temperature response curve, and thus in the intrinsic temperature sensitivity of respiration across the globe. Analyzing measurements in a comprehensive database for 231 species spanning 7 biomes, we demonstrate that temperature-dependent increases in leaf respiration do not follow a commonly used exponential function. Instead, we find a decelerating function as leaves warm, reflecting a declining sensitivity to higher temperatures that is remarkably uniform across all biomes and plant functional types. Such convergence in the temperature sensitivity of leaf respiration suggests that there are universally applicable controls on the temperature response of plant energy metabolism, such that a single new function can predict the temperature dependence of leaf respiration for global vegetation. This simple function enables straightforward description of plant respiration in the land-surface components of coupled earth system models. Our cross-biome analyses shows significant implications for such fluxes in cold climates, generally projecting lower values compared with previous estimates.

  17. Intrinsic climate dependency of ecosystem light and water-use-efficiencies across Australian biomes

    International Nuclear Information System (INIS)

    Shi, Hao; Li, Longhui; Eamus, Derek; Cleverly, James; Huete, Alfredo; Yu, Qiang; Beringer, Jason; Van Gorsel, Eva; Hutley, Lindsay

    2014-01-01

    The sensitivity of ecosystem gross primary production (GPP) to availability of water and photosynthetically active radiation (PAR) differs among biomes. Here we investigated variations of ecosystem light-use-efficiency (eLUE: GPP/PAR) and water-use-efficiency (eWUE: GPP/evapotranspiration) among seven Australian eddy covariance sites with differing annual precipitation, species composition and temperature. Changes to both eLUE and eWUE were primarily correlated with atmospheric vapor pressure deficit (VPD) at multiple temporal scales across biomes, with minor additional correlations observed with soil moisture and temperature. The effects of leaf area index on eLUE and eWUE were also relatively weak compared to VPD, indicating an intrinsic dependency of eLUE and eWUE on climate. Additionally, eLUE and eWUE were statistically different for biomes between summer and winter, except eWUE for savannas and the grassland. These findings will improve our understanding of how light- and water-use traits in Australian ecosystems may respond to climate change. (letter)

  18. Seasonal patterns of horse fly richness and abundance in the Pampa biome of southern Brazil.

    Science.gov (United States)

    Krüger, Rodrigo Ferreira; Krolow, Tiago Kütter

    2015-12-01

    Fluctuations in seasonal patterns of horse fly populations were examined in rainforests of tropical South America, where the climate is seasonal. These patterns were evaluated with robust analytical models rather than identifying the main factors that influenced the fluctuations. We examined the seasonality of populations of horse flies in fields and lowland areas of the Pampa biome of southern Brazil with generalized linear models. We also investigated the diversity of these flies and the sampling effort of Malaise traps in this biome over two years. All of the 29 species had clear seasonality with regard to occurrence and abundance, but only seven species were identified as being influenced by temperature and humidity. The sampling was sufficient and the estimated diversity was 10% more than observed. Seasonal trends were synchronized across species and the populations were most abundant between September and March and nearly zero in other months. While previous studies demonstrated that seasonal patterns in population fluctuations are correlated with climatic conditions in horse fly assemblages in South America rainforests, we show a clear effect of each factor on richness and abundance and the seasonality in the prevalence of horse fly assemblages in localities of the Pampa biome. © 2015 The Society for Vector Ecology.

  19. The future distribution of the savannah biome: model-based and biogeographic contingency.

    Science.gov (United States)

    Moncrieff, Glenn R; Scheiter, Simon; Langan, Liam; Trabucco, Antonio; Higgins, Steven I

    2016-09-19

    The extent of the savannah biome is expected to be profoundly altered by climatic change and increasing atmospheric CO2 concentrations. Contrasting projections are given when using different modelling approaches to estimate future distributions. Furthermore, biogeographic variation within savannahs in plant function and structure is expected to lead to divergent responses to global change. Hence the use of a single model with a single savannah tree type will likely lead to biased projections. Here we compare and contrast projections of South American, African and Australian savannah distributions from the physiologically based Thornley transport resistance statistical distribution model (TTR-SDM)-and three versions of a dynamic vegetation model (DVM) designed and parametrized separately for specific continents. We show that attempting to extrapolate any continent-specific model globally biases projections. By 2070, all DVMs generally project a decrease in the extent of savannahs at their boundary with forests, whereas the TTR-SDM projects a decrease in savannahs at their boundary with aridlands and grasslands. This difference is driven by forest and woodland expansion in response to rising atmospheric CO2 concentrations in DVMs, unaccounted for by the TTR-SDM. We suggest that the most suitable models of the savannah biome for future development are individual-based dynamic vegetation models designed for specific biogeographic regions.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'. © 2016 The Author(s).

  20. Plant phylogeny as a window on the evolution of hyperdiversity in the tropical rainforest biome.

    Science.gov (United States)

    Eiserhardt, Wolf L; Couvreur, Thomas L P; Baker, William J

    2017-06-01

    I. II. III. IV. V. VI. VII. VIII. IX. References SUMMARY: Tropical rainforest (TRF) is the most species-rich terrestrial biome on Earth, harbouring just under half of the world's plant species in c. 7% of the land surface. Phylogenetic trees provide important insights into mechanisms underpinning TRF hyperdiversity that are complementary to those obtained from the fossil record. Phylogenetic studies of TRF plant diversity have mainly focused on whether this biome is an evolutionary 'cradle' or 'museum', emphasizing speciation and extinction rates. However, other explanations, such as biome age, immigration and ecological limits, must also be considered. We present a conceptual framework for addressing the drivers of TRF diversity, and review plant studies that have tested them with phylogenetic data. Although surprisingly few in number, these studies point to old age of TRF, low extinction and high speciation rates as credible drivers of TRF hyperdiversity. There is less evidence for immigration and ecological limits, but these cannot be dismissed owing to the limited number of studies. Rapid methodological developments in DNA sequencing, macroevolutionary analysis and the integration of phylogenetics with other disciplines may improve our grasp of TRF hyperdiversity in the future. However, such advances are critically dependent on fundamental systematic research, yielding numerous, additional, well-sampled phylogenies of TRF lineages. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  1. Reimplementation of the Biome-BGC model to simulate successional change.

    Science.gov (United States)

    Bond-Lamberty, Ben; Gower, Stith T; Ahl, Douglas E; Thornton, Peter E

    2005-04-01

    Biogeochemical process models are increasingly employed to simulate current and future forest dynamics, but most simulate only a single canopy type. This limitation means that mixed stands, canopy succession and understory dynamics cannot be modeled, severe handicaps in many forests. The goals of this study were to develop a version of Biome-BGC that supported multiple, interacting vegetation types, and to assess its performance and limitations by comparing modeled results to published data from a 150-year boreal black spruce (Picea mariana (Mill.) BSP) chronosequence in northern Manitoba, Canada. Model data structures and logic were modified to support an arbitrary number of interacting vegetation types; an explicit height calculation was necessary to prioritize radiation and precipitation interception. Two vegetation types, evergreen needle-leaf and deciduous broadleaf, were modeled based on site-specific meteorological and physiological data. The new version of Biome-BGC reliably simulated observed changes in leaf area, net primary production and carbon stocks, and should be useful for modeling the dynamics of mixed-species stands and ecological succession. We discuss the strengths and limitations of Biome-BGC for this application, and note areas in which further work is necessary for reliable simulation of boreal biogeochemical cycling at a landscape scale.

  2. Modelling the impacts of reoccurring fires in tropical savannahs using Biome-BGC.

    Science.gov (United States)

    Fletcher, Charlotte; Petritsch, Richard; Pietsch, Stephan

    2010-05-01

    Fires are a dominant feature of tropical savannahs and have occurred throughout history by natural as well as human-induced means. These fires have a profound influence on the landscape in terms of flux dynamics and vegetative species composition. This study attempts to understand the impacts of fire regimes on flux dynamics and vegetation composition in savannahs using the Biome-BGC model. The Batéké Plateau, Gabon - an area of savannah grasslands in the Congo basin, serves as a case-study. To achieve model validation for savannahs, data sets from stands with differing levels of past burning are used. It is hypothesised that the field measurements from those stands with lower-levels of past burning will correlate with the Biome-BGC model output, meaning that the model is validated for the savannah excluding fire regimes. However, in reality, fire is frequent in the savannah. Data on past fire events are available from the Moderate Resolution Imaging Spectroradiometer (MODIS) to provide the fire regimes of the model. As the field data-driven measurements of the burnt stands are influenced by fire in the savannah, this will therefore result in a Biome-BGC model validated for the impacts of fire on savannah ecology. The validated model can then be used to predict the savannah's flux dynamics under the fire scenarios expected with climate and/or human impact change.

  3. Development of the BIOME-BGC model for the simulation of managed Moso bamboo forest ecosystems.

    Science.gov (United States)

    Mao, Fangjie; Li, Pingheng; Zhou, Guomo; Du, Huaqiang; Xu, Xiaojun; Shi, Yongjun; Mo, Lufeng; Zhou, Yufeng; Tu, Guoqing

    2016-05-01

    Numerical models are the most appropriate instrument for the analysis of the carbon balance of terrestrial ecosystems and their interactions with changing environmental conditions. The process-based model BIOME-BGC is widely used in simulation of carbon balance within vegetation, litter and soil of unmanaged ecosystems. For Moso bamboo forests, however, simulations with BIOME-BGC are inaccurate in terms of the growing season and the carbon allocation, due to the oversimplified representation of phenology. Our aim was to improve the applicability of BIOME-BGC for managed Moso bamboo forest ecosystem by implementing several new modules, including phenology, carbon allocation, and management. Instead of the simple phenology and carbon allocation representations in the original version, a periodic Moso bamboo phenology and carbon allocation module was implemented, which can handle the processes of Moso bamboo shooting and high growth during "on-year" and "off-year". Four management modules (digging bamboo shoots, selective cutting, obtruncation, fertilization) were integrated in order to quantify the functioning of managed ecosystems. The improved model was calibrated and validated using eddy covariance measurement data collected at a managed Moso bamboo forest site (Anji) during 2011-2013 years. As a result of these developments and calibrations, the performance of the model was substantially improved. Regarding the measured and modeled fluxes (gross primary production, total ecosystem respiration, net ecosystem exchange), relative errors were decreased by 42.23%, 103.02% and 18.67%, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Beyond the climate envelope: using trait filtering models to predict biome boundaries from plant physiology.

    Science.gov (United States)

    Fisher, R.; Hoffmann, W. A.; Muszala, S.

    2014-12-01

    The introduction of second-generation dynamic vegetation models - which simulate the distribution of light resources between plant types along the vertical canopy profile, and therefore facilitate the representation of plant competition explicitly - is a large increase in the complexity and fidelity with which the terrestrial biosphere is abstracted into Earth System Models. In this new class of model, biome boundaries are predicted as the emergent properties of plant physiology, and are therefore sensitive to the high-dimensional parameterizations of plant functional traits. These new approaches offer the facility to quantitatively test ecophysiological hypotheses of plant distribution at large scales, a field which remains surprisingly under-developed. Here we describe experiments conducted with the Community Land Model Ecosystem Demography component, CLM(ED), in which we reduce the complexity of the problem by testing how individual plant functional trait changes to control the location of biome boundaries between functional types. Specifically, we investigate which physiological trade-offs determine the boundary between frequently burned savanna and forest biomes, and attempt to distinguish how each strategic life-history trade-off (carbon storage, bark investment, re-sprouting strategy) contributes towards the maintenance of sharp geographical gradients between fire adapted and typically inflammable closed canopy ecosystems. This study forms part of the planning for a model-inspired fire manipulation experiment at the cerrado-forest boundary in South-Eastern Brazil, and the results will be used to guide future data-collection and analysis strategies.

  5. ANTIBACTERIAL POTENTIAL OF NATIVE PLANTS FROM THE CAATINGA BIOME AGAINST Staphylococcus spp. ISOLATES FROM SMALL RUMINANTS WITH MASTITIS

    OpenAIRE

    PEIXOTO, RODOLFO DE MORAES; SILVA, WELLINGTON ERASMO LIMA E; ALMEIDA, JACKSON ROBERTO GUEDES SILVA; BRANCO, ALEXSANDRO; COSTA, MATEUS MATIUZZI DA

    2016-01-01

    ABSTRACT The aim of the present study is to assess the antibacterial potential of plants from the Caatinga biome of the semi-arid region of Pernambuco, against Staphylococcus spp. isolates from cases of subclinical mastitis in small ruminants, such as goats and ewes. Ethanolic extracts of the following plants from the Caatinga biome were used: Encholirium spectabile Mart., Bromelia laciniosa Mart., Neoglaziovia variegata Mez., Amburana cearensis (Fr. Allem.) A. C. Smith, Hymenaea martiana Hay...

  6. Modelling the carbon budget of intensive forest monitoring sites in Germany using the simulation model BIOME-BGC

    OpenAIRE

    Jochheim, H.; Puhlmann, M.; Beese, F.; Berthold, D.; Einert, P.; Kallweit, R.; Konopatzky, A.; Meesenburg, H.; Meiwes, K.-J.; Raspe, S.; Schulte-Bisping, H.; Schulz, C.

    2008-01-01

    It is shown that by calibrating the simulation model BIOME-BGC with mandatory and optional Level II data, within the ICP Forest programme, a well-founded calculation of the carbon budget of forest stands is achievable and, based on succeeded calibration, the modified BIOME-BGC model is a useful tool to assess the effect of climate change on forest ecosystems. peerReviewed

  7. Evolutionary history of a keystone pollinator parallels the biome occupancy of angiosperms in the Greater Cape Floristic Region.

    Science.gov (United States)

    de Jager, Marinus L; Ellis, Allan G

    2017-02-01

    The Greater Cape Floristic Region (GCFR) in South Africa has been extensively investigated for its phenomenal angiosperm diversity. A key emergent pattern is the occurrence of older plant lineages in the southern Fynbos biome and younger lineages in the northern Succulent Karoo biome. We know practically nothing, however, about the evolutionary history of the animals that pollinate this often highly-specialized flora. In this study, we explore the evolutionary history of an important GCFR fly pollinator, Megapalpus capensis, and ask whether it exhibits broadly congruent genetic structuring and timing of diversification to flowering plants within these biomes. We find that the oldest M. capensis lineages originated in Fynbos during the Miocene, while younger Succulent Karoo lineages diverged in the Pliocene and correspond to the proposed age of this recent biome. A strong signature of population expansion is also recovered for flies in this arid biome, consistent with recent colonization. Our first investigation into the evolutionary history of GCFR pollinators thus supports a recent origin of the SK biome, as inferred from angiosperm phylogenies, and suggests that plants and pollinators may have co-diverged within this remarkable area. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Intelligent system for topic survey in MEDLINE by keyword recommendation and learning text characteristics.

    Science.gov (United States)

    Tanaka, M; Nakazono, S; Matsuno, H; Tsujimoto, H; Kitamura, Y; Miyano, S

    2000-01-01

    We have implemented a system for assisting experts in selecting MEDLINE records for database construction purposes. This system has two specific features: The first is a learning mechanism which extracts characteristics in the abstracts of MEDLINE records of interest as patterns. These patterns reflect selection decisions by experts and are used for screening the records. The second is a keyword recommendation system which assists and supplements experts' knowledge in unexpected cases. Combined with a conventional keyword-based information retrieval system, this system may provide an efficient and comfortable environment for MEDLINE record selection by experts. Some computational experiments are provided to prove that this idea is useful.

  9. MedlinePlus® Everywhere: Access from Your Phone, Tablet or Desktop

    Science.gov (United States)

    ... responsivefull.html MedlinePlus® Everywhere: Access from Your Phone, Tablet or Desktop To use the sharing features on ... provide a consistent user experience from a desktop, tablet, or phone. All users, regardless of how they ...

  10. A Leader in Clinical Trials, Medical Data, & Electronic Health Information | NIH MedlinePlus the Magazine

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    ... of C. Everett Koop, the former Surgeon General; Charles Drew, the “father of the blood bank”; Rosalind ... MedlinePlus information resources about prescriptions. Soon, such information will be available through one click on the name ...

  11. For Distinguished Public Service: Medical Library Association Honors FNLM and NIH MedlinePlus Magazine | NIH ...

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    ... Medical Library Association Honors FNLM and NIH MedlinePlus Magazine Past Issues / Summer 2011 Table of Contents MLA ... From You We want your feedback on the magazine and ideas for future issues, as well as ...

  12. The Match of Her Life | NIH MedlinePlus the Magazine

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    ... answer questions for this issue of NIH MedlinePlus magazine about her breast cancer. You discovered you had ... way of healing. As this issue of the magazine went to press, Navratilova was receiving radiation therapy ...

  13. FNLM 2013 Events & Programs Announced | NIH MedlinePlus the Magazine

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    ... study in their field of expertise. Annual Awards Dinner In 2013, the Awards Dinner to celebrate advances ... Mobile MedlinePlus! Trusted medical information on your mobile phone. http://m.medlineplus.gov and in Spanish at ...

  14. To Your Health: NLM update transcript - NIH MedlinePlus magazine Winter 2018

    Science.gov (United States)

    ... who is a star of 'The Big Bang Theory' television show, and the producer/narrator of a ... trials, NIH MedlinePlus magazine reports the current life expectancy of a person with sickle cell disease is ...

  15. NIH Launches National COPD Action Plan | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... COPD Action Plan Follow us NIH Launches National COPD Action Plan Photo: National Heart, Lung, and Blood ... questions for NIH MedlinePlus magazine. Why was the COPD National Action Plan created? The staggering numbers associated ...

  16. Annotating patents with Medline MeSH codes via citation mapping.

    Science.gov (United States)

    Griffin, Thomas D; Boyer, Stephen K; Councill, Isaac G

    2010-01-01

    Both patents and Medline are important document collections for discovering new relationships between chemicals and biology, searching for prior art for patent applications and retrieving background knowledge for current research activities. Finding relevance to a topic within patents is often made difficult by poor categorization, badly written descriptions, and even intentional obfuscation. Unlike patents, the Medline corpus has Medical Subject Heading (MeSH) keywords manually added to their articles, giving a medically relevant taxonomy to the 18 million article abstracts. Our work attempts to accurately recognize the citations made in patents to Medline-indexed articles, linking them to their corresponding PubMed ID and exploiting the associated MeSH to enhance patent search by annotating the referencing patents with their Medline citations' MeSH codes. The techniques, system features, and benefits are explained.

  17. Technical development of PubMed Interact: an improved interface for MEDLINE/PubMed searches

    OpenAIRE

    Muin, Michael; Fontelo, Paul

    2006-01-01

    Abstract Background The project aims to create an alternative search interface for MEDLINE/PubMed that may provide assistance to the novice user and added convenience to the advanced user. An earlier version of the project was the 'Slider Interface for MEDLINE/PubMed searches' (SLIM) which provided JavaScript slider bars to control search parameters. In this new version, recent developments in Web-based technologies were implemented. These changes may prove to be even more valuable in enhanci...

  18. Morphofunctional diversity of equine of varied genetic compositions raised in the Pantanal biome of Brazil.

    Science.gov (United States)

    de Rezende, Marcos Paulo Gonçalves; de Souza, Julio Cesar; Carneiro, Paulo Luiz Souza; Bozzi, Riccardo; Jardim, Rodrigo Jose Delgado; Malhado, Carlos Henrique Mendes

    2018-06-01

    Evaluating phenotypic diversity makes it possible to identify discrepancies in aptitudes among animals of different genetic bases, which is an indicator of adaptive or selective differences between populations. The objective of this work was to evaluate the morphofunctional diversity of 452 male and female adult equines (Arabian, Quarter Mile, Pantaneiro, and Criollo breeds, and undefined crossbreeds of horses and mules) raised in the Pantanal biome (Brazil). Linear measurements were performed to estimate conformation indexes. Initially, a discriminant analysis was performed, regardless of the animal's size, followed by factor analysis. The factors were characterized and used as new variables. The diversity among equines and their relationship with the factors were evaluated using multivariate analysis. The factors were classified according to their decreasing importance: balance, rusticity, and robustness for the measurement factors; and load, ability, conformation, and equilibrium for the index factors. The genetic groups of equines have well-defined morphofunctional characteristics. The main differences are based on the rusticity and ability typologies in relation to those based on performance. Equines introduced to the Pantanal biome presented a more robust and compact body with good conformation. As a result, these horses may have superior athletic performance during equestrian activities when compared to the Pantaneiro local breed. However, this biotype may represent less rusticity (less adaptive capacity). Therefore, the regional breed can be equal or better in equestrian activities than breeds introduced to the Pantanal biome. Thus, breeders may cross horses from local breeds as an alternative to those introduced. Undefined crossbred male equines presented a different profile from the Pantaneiro breed, which may indicate little use of crossbreeds in breeding.

  19. Identification of priority conservation areas and potential corridors for jaguars in the Caatinga biome, Brazil.

    Science.gov (United States)

    Morato, Ronaldo Gonçalves; Ferraz, Katia Maria Paschoaletto Micchi de Barros; de Paula, Rogério Cunha; de Campos, Cláudia Bueno

    2014-01-01

    The jaguar, Panthera onca, is a top predator with the extant population found within the Brazilian Caatinga biome now known to be on the brink of extinction. Designing new conservation units and potential corridors are therefore crucial for the long-term survival of the species within the Caatinga biome. Thus, our aims were: 1) to recognize suitable areas for jaguar occurrence, 2) to delineate areas for jaguar conservation (PJCUs), 3) to design corridors among priority areas, and 4) to prioritize PJCUs. A total of 62 points records of jaguar occurrence and 10 potential predictors were analyzed in a GIS environment. A predictive distributional map was obtained using Species Distribution Modeling (SDM) as performed by the Maximum Entropy (Maxent) algorithm. Areas equal to or higher than the median suitability value of 0.595 were selected as of high suitability for jaguar occurrence and named as Priority Jaguar Conservation Units (PJCU). Ten PJCUs with sizes varying from 23.6 km2 to 4,311.0 km2 were identified. Afterwards, we combined the response curve, as generated by SDM, and expert opinions to create a permeability matrix and to identify least cost corridors and buffer zones between each PJCU pair. Connectivity corridors and buffer zone for jaguar movement included an area of 8.884,26 km2 and the total corridor length is about 160.94 km. Prioritizing criteria indicated the PJCU representing c.a. 68.61% of the total PJCU area (PJCU # 1) as of high priority for conservation and connectivity with others PJCUs (PJCUs # 4, 5 and 7) desirable for the long term survival of the species. In conclusion, by using the jaguar as a focal species and combining SDM and expert opinion we were able to create a valid framework for practical conservation actions at the Caatinga biome. The same approach could be used for the conservation of other carnivores.

  20. Identification of priority conservation areas and potential corridors for jaguars in the Caatinga biome, Brazil.

    Directory of Open Access Journals (Sweden)

    Ronaldo Gonçalves Morato

    Full Text Available The jaguar, Panthera onca, is a top predator with the extant population found within the Brazilian Caatinga biome now known to be on the brink of extinction. Designing new conservation units and potential corridors are therefore crucial for the long-term survival of the species within the Caatinga biome. Thus, our aims were: 1 to recognize suitable areas for jaguar occurrence, 2 to delineate areas for jaguar conservation (PJCUs, 3 to design corridors among priority areas, and 4 to prioritize PJCUs. A total of 62 points records of jaguar occurrence and 10 potential predictors were analyzed in a GIS environment. A predictive distributional map was obtained using Species Distribution Modeling (SDM as performed by the Maximum Entropy (Maxent algorithm. Areas equal to or higher than the median suitability value of 0.595 were selected as of high suitability for jaguar occurrence and named as Priority Jaguar Conservation Units (PJCU. Ten PJCUs with sizes varying from 23.6 km2 to 4,311.0 km2 were identified. Afterwards, we combined the response curve, as generated by SDM, and expert opinions to create a permeability matrix and to identify least cost corridors and buffer zones between each PJCU pair. Connectivity corridors and buffer zone for jaguar movement included an area of 8.884,26 km2 and the total corridor length is about 160.94 km. Prioritizing criteria indicated the PJCU representing c.a. 68.61% of the total PJCU area (PJCU # 1 as of high priority for conservation and connectivity with others PJCUs (PJCUs # 4, 5 and 7 desirable for the long term survival of the species. In conclusion, by using the jaguar as a focal species and combining SDM and expert opinion we were able to create a valid framework for practical conservation actions at the Caatinga biome. The same approach could be used for the conservation of other carnivores.

  1. Reactivity continuum modeling of leaf, root, and wood decomposition across biomes

    Science.gov (United States)

    Koehler, Birgit; Tranvik, Lars J.

    2015-07-01

    Large carbon dioxide amounts are released to the atmosphere during organic matter decomposition. Yet the large-scale and long-term regulation of this critical process in global carbon cycling by litter chemistry and climate remains poorly understood. We used reactivity continuum (RC) modeling to analyze the decadal data set of the "Long-term Intersite Decomposition Experiment," in which fine litter and wood decomposition was studied in eight biome types (224 time series). In 32 and 46% of all sites the litter content of the acid-unhydrolyzable residue (AUR, formerly referred to as lignin) and the AUR/nitrogen ratio, respectively, retarded initial decomposition rates. This initial rate-retarding effect generally disappeared within the first year of decomposition, and rate-stimulating effects of nutrients and a rate-retarding effect of the carbon/nitrogen ratio became more prevalent. For needles and leaves/grasses, the influence of climate on decomposition decreased over time. For fine roots, the climatic influence was initially smaller but increased toward later-stage decomposition. The climate decomposition index was the strongest climatic predictor of decomposition. The similar variability in initial decomposition rates across litter categories as across biome types suggested that future changes in decomposition may be dominated by warming-induced changes in plant community composition. In general, the RC model parameters successfully predicted independent decomposition data for the different litter-biome combinations (196 time series). We argue that parameterization of large-scale decomposition models with RC model parameters, as opposed to the currently common discrete multiexponential models, could significantly improve their mechanistic foundation and predictive accuracy across climate zones and litter categories.

  2. Clonality analysis of lymphoid proliferations using the BIOMED-2 clonality assays: a single institution experience

    Science.gov (United States)

    Kokovic, Ira; Novakovic, Barbara Jezersek; Cerkovnik, Petra; Novakovic, Srdjan

    2014-01-01

    Background Clonality determination in patients with lymphoproliferative disorders can improve the final diagnosis. The aim of our study was to evaluate the applicative value of standardized BIOMED-2 gene clonality assay protocols for the analysis of clonality of lymphocytes in a group of different lymphoid proliferations. Materials and methods. With this purpose, 121 specimens from 91 patients with suspected lymphoproliferations submitted for routine diagnostics from January to December 2011 were retrospectively analyzed. According to the final diagnosis, our series comprised 32 cases of B-cell lymphomas, 38 cases of non-Hodgkin’s T-cell lymphomas and 51 cases of reactive lymphoid proliferations. Clonality testing was performed using the BIOMED-2 clonality assays. Results The determined sensitivity of the TCR assay was 91.9%, while the sensitivity of the IGH assay was 74.2%. The determined specificity of the IGH assay was 73.3% in the group of lymphomas and 87.2% in the group of reactive lesions. The determined specificity of the TCR assay was 62.5% in the group of lymphomas and 54.3% in the group of reactive lesions. Conclusions In the present study, we confirmed the utility of standardized BIOMED-2 clonality assays for the detection of clonality in a routine diagnostical setting of non-Hodgkin’s lymphomas. Reactions for the detection of the complete IGH rearrangements and reactions for the detection of the TCR rearrangements are a good choice for clonality testing of a wide range of lymphoid proliferations and specimen types while the reactions for the detection of incomplete IGH rearrangements have not shown any additional diagnostic value. PMID:24991205

  3. Global soil-climate-biome diagram: linking soil properties to climate and biota

    Science.gov (United States)

    Zhao, X.; Yang, Y.; Fang, J.

    2017-12-01

    As a critical component of the Earth system, soils interact strongly with both climate and biota and provide fundamental ecosystem services that maintain food, climate, and human security. Despite significant progress in digital soil mapping techniques and the rapidly growing quantity of observed soil information, quantitative linkages between soil properties, climate and biota at the global scale remain unclear. By compiling a large global soil database, we mapped seven major soil properties (bulk density [BD]; sand, silt and clay fractions; soil pH; soil organic carbon [SOC] density [SOCD]; and soil total nitrogen [STN] density [STND]) based on machine learning algorithms (regional random forest [RF] model) and quantitatively assessed the linkage between soil properties, climate and biota at the global scale. Our results demonstrated a global soil-climate-biome diagram, which improves our understanding of the strong correspondence between soils, climate and biomes. Soil pH decreased with greater mean annual precipitation (MAP) and lower mean annual temperature (MAT), and the critical MAP for the transition from alkaline to acidic soil pH decreased with decreasing MAT. Specifically, the critical MAP ranged from 400-500 mm when the MAT exceeded 10 °C but could decrease to 50-100 mm when the MAT was approximately 0 °C. SOCD and STND were tightly linked; both increased in accordance with lower MAT and higher MAP across terrestrial biomes. Global stocks of SOC and STN were estimated to be 788 ± 39.4 Pg (1015 g, or billion tons) and 63 ± 3.3 Pg in the upper 30-cm soil layer, respectively, but these values increased to 1654 ± 94.5 Pg and 133 ± 7.8 Pg in the upper 100-cm soil layer, respectively. These results reveal quantitative linkages between soil properties, climate and biota at the global scale, suggesting co-evolution of the soil, climate and biota under conditions of global environmental change.

  4. Is a Widely Available Cure for Sickle Cell Disease on the Horizon? | NIH MedlinePlus the Magazine

    Science.gov (United States)

    Skip to main content NIH MedlinePlus the Magazine NIH MedlinePlus Salud Download the Current Issue PDF [1.5 mb] Trusted Health Information from the National Institutes of Health Home Current Issue ...

  5. Journalist Liz Hernandez hopes to make Alzheimer’s a thing of the past | NIH MedlinePlus the Magazine

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    Skip to main content NIH MedlinePlus the Magazine NIH MedlinePlus Salud Download the Current Issue PDF [4.3 mb] Trusted Health Information from the National Institutes of Health Home Current Issue ...

  6. Finding Better and More Personalized Ways to Diagnose Cancer at NIH | NIH MedlinePlus the Magazine

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    Skip to main content NIH MedlinePlus the Magazine NIH MedlinePlus Salud Download the Current Issue PDF [3.1 mb] Trusted Health Information from the National Institutes of Health Home Current Issue ...

  7. From the lab - CancerSEEK: Blood Test Could Detect Cancer Earlier | NIH MedlinePlus the Magazine

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    Skip to main content NIH MedlinePlus the Magazine NIH MedlinePlus Salud Download the Current Issue PDF [3.1 mb] Trusted Health Information from the National Institutes of Health Home Current Issue ...

  8. From Bench to Bedside: Researchers of NIH’s Clinical Center | NIH MedlinePlus the Magazine

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    Skip to main content NIH MedlinePlus the Magazine NIH MedlinePlus Salud Download the Current Issue PDF [1.5 mb] Trusted Health Information from the National Institutes of Health Home Current Issue ...

  9. From the lab - Brain Scan Technology Extends Treatment Window for Stroke | NIH MedlinePlus the Magazine

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  10. Biomímesis: una propuesta ética y técnica para reorientar la ingeniería por los senderos de la sustentabilidad

    Directory of Open Access Journals (Sweden)

    Nicolás Jiménez Iguarán

    2016-01-01

    Full Text Available Nos encontramos en lo que el intelectual español Jorge Riechmann denomina “el siglo de la gran prueba”. La actual crisis ambiental, cuyos síntomas no dejan de aparecer, nos impone retos en todos los niveles de nuestra vida. El presente trabajo tiene el propósito de explorar las potencialidades que tiene la ingeniería para superar esta crisis (o “prueba”, a la luz de la categoría biomímesis. Para esto, partimos de una reflexión central sobre la correspondencia entre el saber técnico ingenieril, los límites de la naturaleza y la noción de progreso para, a partir de ella, realizar una crítica propositiva a la ingeniería e inferir algunos elementos éticos que encaminen su desarrollo. Como ciencia aplicada, la ingeniería forma parte de nuestras vidas así no seamos plenamente conscientes de ello. En su desarrollo y evolución ha contribuido a producir sobrecargas significativas en la biósfera. La ética ambiental ha venido insistiendo, durante más de cinco décadas, en la necesidad de reconducir nuestra civilización hacia técnicas aplicadas que aprendan de la naturaleza en lugar de degradarla. La biomímesis, al recordar que los resultados de la ingeniería deben estar asociados a un objetivo social colectivo, se presenta como un camino para superar esta compleja realidad.

  11. Sensitivity Analysis of Biome-Bgc Model for Dry Tropical Forests of Vindhyan Highlands, India

    Science.gov (United States)

    Kumar, M.; Raghubanshi, A. S.

    2011-08-01

    A process-based model BIOME-BGC was run for sensitivity analysis to see the effect of ecophysiological parameters on net primary production (NPP) of dry tropical forest of India. The sensitivity test reveals that the forest NPP was highly sensitive to the following ecophysiological parameters: Canopy light extinction coefficient (k), Canopy average specific leaf area (SLA), New stem C : New leaf C (SC:LC), Maximum stomatal conductance (gs,max), C:N of fine roots (C:Nfr), All-sided to projected leaf area ratio and Canopy water interception coefficient (Wint). Therefore, these parameters need more precision and attention during estimation and observation in the field studies.

  12. SENSITIVITY ANALYSIS OF BIOME-BGC MODEL FOR DRY TROPICAL FORESTS OF VINDHYAN HIGHLANDS, INDIA

    OpenAIRE

    M. Kumar; A. S. Raghubanshi

    2012-01-01

    A process-based model BIOME-BGC was run for sensitivity analysis to see the effect of ecophysiological parameters on net primary production (NPP) of dry tropical forest of India. The sensitivity test reveals that the forest NPP was highly sensitive to the following ecophysiological parameters: Canopy light extinction coefficient (k), Canopy average specific leaf area (SLA), New stem C : New leaf C (SC:LC), Maximum stomatal conductance (gs,max), C:N of fine roots (C:Nfr), All-sided to...

  13. Characterizing forest carbon stocks at tropical biome and landscape level in Mount Apo National Park, Philippines

    Science.gov (United States)

    Rubas, L. C.

    2012-12-01

    Forest resources sequester and store carbon, and serve as a natural brake on climate change. In the tropics, the largest source of greenhouse emission is from deforestation and forest degradation (Gibbs et al 2007). This paper attempts to compile sixty (60) existing studies on using remote sensing to measure key environmental forest indicators at two levels of scales: biome and landscape level. At the tropical forest biome level, there is not as much remote sensing studies that have been done as compared to other forest biomes. Also, existing studies on tropical Asia is still sparse compared to other tropical regions in Latin America and Africa. Biomass map is also produced for the tropical biome using keyhole macro language (KML) which is projected on Google Earth. The compiled studies showed there are four indicators being measured using remote sensors in tropical forest. These are biomass, landcover classification, deforestation and cloud cover. The landscape level will focus on Mount Apo National Park in the Philippines which is encompassing a total area of 54,974.87 hectares. It is one of the ten priority sites targeted in the World Bank-assisted Biodiversity Conservation Program. This park serves as the major watershed for the three provinces with 19 major rivers emanating from the montane formations. Only a small fraction of the natural forest that once covered the country remains. In spite of different policies that aim to reduce logging recent commercial deforestation, illegal logging and agricultural expansion pose an important threat to the remaining forest areas. In some locations in the country, these hotspots of deforestation overlap with the protected areas (Verburg et al 2006). The study site was clipped using ArcGIS from the forest biomass carbon density map produced by Gibbs and Brown (2007). Characterization on this national park using vegetation density, elevation, slope, land cover and precipitation will be conducted to determine factors that

  14. Extensiones biométricas para bases de datos objeto- relacionales

    OpenAIRE

    Miranda, Ernesto; Ruíz, Silvia; Aguirre, Juan José; Herlein, Mauro; Etchart, Graciela; Alvez, Carlos E.

    2017-01-01

    La autenticación de personas basadas en rasgos biométricos se ha vuelto muy popular en los últimos años como consecuencia de la baja en los costos de los sensores requeridos, su inclusión en dispositivos de consumo masivo y el surgimiento de vulnerabilidades debido al uso de múltiples claves de acceso a diferentes sitios que requieren cierto nivel de seguridad como ser cuentas de correo, sitios de banca electrónica, sistemas corporativos, etc. De todos los rasgos utilizados en biometría, el i...

  15. Impacts of land-use and land-cover change on stream hydrochemistry in the Cerrado and Amazon biomes.

    Science.gov (United States)

    Nóbrega, Rodolfo L B; Guzha, Alphonce C; Lamparter, Gabriele; Amorim, Ricardo S S; Couto, Eduardo G; Hughes, Harold J; Jungkunst, Hermann F; Gerold, Gerhard

    2018-04-14

    Studies on the impacts of land-use and land-cover change on stream hydrochemistry in active deforestation zones of the Amazon agricultural frontier are limited and have often used low-temporal-resolution datasets. Moreover, these impacts are not concurrently assessed in well-established agricultural areas and new deforestations hotspots. We aimed to identify these impacts using an experimental setup to collect high-temporal-resolution hydrological and hydrochemical data in two pairs of low-order streams in catchments under contrasting land use and land cover (native vegetation vs. pasture) in the Amazon and Cerrado biomes. Our results indicate that the conversion of natural landscapes to pastures increases carbon and nutrient fluxes via streamflow in both biomes. These changes were the greatest in total inorganic carbon in the Amazon and in potassium in the Cerrado, representing a 5.0- and 5.5-fold increase in the fluxes of each biome, respectively. We found that stormflow, which is often neglected in studies on stream hydrochemistry in the tropics, plays a substantial role in the carbon and nutrient fluxes, especially in the Amazon biome, as its contributions to hydrochemical fluxes are mostly greater than the volumetric contribution to the total streamflow. These findings demonstrate that assessments of the impacts of deforestation in the Amazon and Cerrado biomes should also take into account rapid hydrological pathways; however, this can only be achieved through collection of high-temporal-resolution data. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Large-scale impact of climate change vs. land-use change on future biome shifts in Latin America.

    Science.gov (United States)

    Boit, Alice; Sakschewski, Boris; Boysen, Lena; Cano-Crespo, Ana; Clement, Jan; Garcia-Alaniz, Nashieli; Kok, Kasper; Kolb, Melanie; Langerwisch, Fanny; Rammig, Anja; Sachse, René; van Eupen, Michiel; von Bloh, Werner; Clara Zemp, Delphine; Thonicke, Kirsten

    2016-11-01

    Climate change and land-use change are two major drivers of biome shifts causing habitat and biodiversity loss. What is missing is a continental-scale future projection of the estimated relative impacts of both drivers on biome shifts over the course of this century. Here, we provide such a projection for the biodiverse region of Latin America under four socio-economic development scenarios. We find that across all scenarios 5-6% of the total area will undergo biome shifts that can be attributed to climate change until 2099. The relative impact of climate change on biome shifts may overtake land-use change even under an optimistic climate scenario, if land-use expansion is halted by the mid-century. We suggest that constraining land-use change and preserving the remaining natural vegetation early during this century creates opportunities to mitigate climate-change impacts during the second half of this century. Our results may guide the evaluation of socio-economic scenarios in terms of their potential for biome conservation under global change. © 2016 John Wiley & Sons Ltd.

  17. Biome depletion in conjunction with evolutionary mismatches could play a role in the etiology of neurofibromatosis 1.

    Science.gov (United States)

    Beales, Donna L

    2015-04-01

    Neurofibromatosis 1 (NF1) arises de novo in a striking 30-50% of cases, pointing toward an environmental etiology, though none has been clearly identified. The Biome Depletion Theory posits that the absence of mutualistic and commensal organisms within the human body coupled with modern lifestyle alterations may have profoundly deleterious effects, inclusive of immunologic derangement that is thought to result in allergy, atopy, and numerous autoimmune diseases. Biome depletion has been implicated as a factor in the etiology of both multiple sclerosis and autism spectrum disorders; biome reconstitution, i.e. replenishment of the biome with certain keynote species, is being used in the treatment of these and other autoimmune states. Neurofibromatosis 1 has been associated with allergy, various autoimmune states, multiple sclerosis, and autism. Recent research has posited that NF1, multiple sclerosis and autism may all arise from disturbances in the neural crest during gestation. This paper hypothesizes that there is indirect evidence that a highly inflammatory uterine state may precipitate epigenetic changes in vulnerable NF-related genes in the course of fetal development. The etiology of NF1 may lie in the absence of immunomodulation by commensal and mutualistic species once ubiquitously present in the environment, as well as through adoption of a modern lifestyle that contributes to chronic inflammation. Replenishment of helminths and other missing organisms to the human biome prior to conception as well as addressing nutritional status, psychological stress, and environmental exposures may prevent the development of NF1. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Terrestrial ecosystem process model Biome-BGCMuSo v4.0: summary of improvements and new modeling possibilities

    Science.gov (United States)

    Hidy, Dóra; Barcza, Zoltán; Marjanović, Hrvoje; Zorana Ostrogović Sever, Maša; Dobor, Laura; Gelybó, Györgyi; Fodor, Nándor; Pintér, Krisztina; Churkina, Galina; Running, Steven; Thornton, Peter; Bellocchi, Gianni; Haszpra, László; Horváth, Ferenc; Suyker, Andrew; Nagy, Zoltán

    2016-12-01

    The process-based biogeochemical model Biome-BGC was enhanced to improve its ability to simulate carbon, nitrogen, and water cycles of various terrestrial ecosystems under contrasting management activities. Biome-BGC version 4.1.1 was used as a base model. Improvements included addition of new modules such as the multilayer soil module, implementation of processes related to soil moisture and nitrogen balance, soil-moisture-related plant senescence, and phenological development. Vegetation management modules with annually varying options were also implemented to simulate management practices of grasslands (mowing, grazing), croplands (ploughing, fertilizer application, planting, harvesting), and forests (thinning). New carbon and nitrogen pools have been defined to simulate yield and soft stem development of herbaceous ecosystems. The model version containing all developments is referred to as Biome-BGCMuSo (Biome-BGC with multilayer soil module; in this paper, Biome-BGCMuSo v4.0 is documented). Case studies on a managed forest, cropland, and grassland are presented to demonstrate the effect of model developments on the simulation of plant growth as well as on carbon and water balance.

  19. Aspectos biométricos do desenvolvimento testicular e corporal em cutias (Dasyprocta aguti criadas em cativeiros

    Directory of Open Access Journals (Sweden)

    Antônio Chaves de Assis-Neto

    2003-01-01

    Full Text Available Analisou-se os dados biométricos do desenvolvimento testicular e peso corporal de 31 cutias (Dasyprocta aguti desde o nascimento até os 14 meses de idade. As correlações entre o peso corporal, idade e parâmetros testiculares apresentaram-se altamente significativas. O peso testicular, o volume testicular, assim como os demais parâmetros biométricos testiculares (comprimento, diâmetro e perímetro, evoluíram lenta e gradualmente até os 8 meses de idade. A partir dos 9 meses, o crescimento foi mais rápido. O desenvolvimento biométrico do testículo pode ser dividido em duas fases, de 0 - 8 meses e de 9 - 14 meses de idade, sendo 9 meses considerado ponto de corte em se tratando de desenvolvimento testicular de cutias criadas em cativeiro.

  20. The Use of Fire Radiative Power to Estimate the Biomass Consumption Coefficient for Temperate Grasslands in the Atlantic Forest Biome

    Directory of Open Access Journals (Sweden)

    Bibiana Salvador Cabral da Costa

    Full Text Available Abstract Every year, many active fire spots are identified in the satellite images of the southern Brazilian grasslands in the Atlantic Forest biome and Pampa biome. Fire Radiative Power (FRP is a technique that uses remotely sensed data to quantify burned biomass. FRP measures the radiant energy released per time unit by burning vegetation. This study aims to use satellite and field data to estimate the biomass consumption rate and the biomass consumption coefficient for the southern Brazilian grasslands. Three fire points were identified in satellite FRP products. These data were combined with field data, collected through literature review, to calculate the biomass consumption coefficient. The type of vegetation is an important variable in the estimation of the biomass consumption coefficient. The biomass consumption rate was estimated to be 2.237 kg s-1 for the southern Brazilian grasslands in Atlantic Forest biome, and the biomass consumption coefficient was estimated to be 0.242 kg MJ-1.

  1. Cross-biome metagenomic analyses of soil microbial communities and their functional attributes.

    Science.gov (United States)

    Fierer, Noah; Leff, Jonathan W; Adams, Byron J; Nielsen, Uffe N; Bates, Scott Thomas; Lauber, Christian L; Owens, Sarah; Gilbert, Jack A; Wall, Diana H; Caporaso, J Gregory

    2012-12-26

    For centuries ecologists have studied how the diversity and functional traits of plant and animal communities vary across biomes. In contrast, we have only just begun exploring similar questions for soil microbial communities despite soil microbes being the dominant engines of biogeochemical cycles and a major pool of living biomass in terrestrial ecosystems. We used metagenomic sequencing to compare the composition and functional attributes of 16 soil microbial communities collected from cold deserts, hot deserts, forests, grasslands, and tundra. Those communities found in plant-free cold desert soils typically had the lowest levels of functional diversity (diversity of protein-coding gene categories) and the lowest levels of phylogenetic and taxonomic diversity. Across all soils, functional beta diversity was strongly correlated with taxonomic and phylogenetic beta diversity; the desert microbial communities were clearly distinct from the nondesert communities regardless of the metric used. The desert communities had higher relative abundances of genes associated with osmoregulation and dormancy, but lower relative abundances of genes associated with nutrient cycling and the catabolism of plant-derived organic compounds. Antibiotic resistance genes were consistently threefold less abundant in the desert soils than in the nondesert soils, suggesting that abiotic conditions, not competitive interactions, are more important in shaping the desert microbial communities. As the most comprehensive survey of soil taxonomic, phylogenetic, and functional diversity to date, this study demonstrates that metagenomic approaches can be used to build a predictive understanding of how microbial diversity and function vary across terrestrial biomes.

  2. Detection of wild animals as carriers of Leptospira by PCR in the Pantanal biome, Brazil.

    Science.gov (United States)

    Vieira, Anahi S; Narduche, Lorena; Martins, Gabriel; Schabib Péres, Igor A H F; Zimmermann, Namor P; Juliano, Raquel S; Pellegrin, Aiesca O; Lilenbaum, Walter

    2016-11-01

    Leptospiral infection is widespread in wildlife. In this context, wild ecosystems in tropical countries hold a vast biodiversity, including several species that may act as potential reservoirs of leptospires. The Pantanal biome presents highly favorable environmental conditions for the occurrence of leptospirosis, such as high temperatures, constant flooding, and high biodiversity. The purpose of this study was to detect wild animals as carriers of Leptospira sp. using direct methods (PCR and culture) in the Pantanal biome, Brazil. A total of 35 animals were studied, namely Cerdocyon thous, Nasua nasua, Ozotoceros bezoarticus, and Sus scrofa species. Blood for serology (MAT) and urine for bacteriological culturing and PCR was sampled. The most prevalent serogroups were Javanica and Djasiman. Additionally, 40.6% of these animals presented PCR positive reactions. Seroreactivity associated with the high frequency of leptospiral carriers among the different studied species suggests a high level of exposure of the studied animals to pathogenic Leptospira strains. Our results are still limited and the actual role of the studied animals in the epidemiology of leptospirosis in the Pantanal region remains to be elucidated. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Temporal profiles of vegetation indices for characterizing grazing intensity on natural grasslands in Pampa biome

    Directory of Open Access Journals (Sweden)

    Amanda Heemann Junges

    2016-08-01

    Full Text Available ABSTRACT The Pampa biome is an important ecosystem in Brazil that is highly relevant to livestock production. The objective of this study was to analyze the potential use of vegetation indices to discriminate grazing intensities on natural grasslands in the Pampa biome. Moderate Resolution Imaging Spectroradiometer (MODIS Normalized Difference Vegetation Index (NDVI and Enhanced Vegetation Index (EVI images from Jan to Dec, 2000 to 2013 series, were analyzed for natural grassland experimental units managed under high (forage allowance of 5 ± 2 % live weight – LW, moderate (13 ± 5 % LW and low grazing intensity (19 ± 7 % LW. Regardless of intensity, the temporal profiles showed lower NDVI and EVI during winter, increased values in spring because of summer species regrowth, slightly decreased values in summer, especially in years when there is a water deficit, and increased values in the fall associated with the beginning of winter forage development. The average temporal profiles of moderate grazing intensity exhibited greater vegetation index values compared with low and high grazing intensities. The temporal profiles of less vegetation index were associated with lower green biomass accumulation caused by the negative impact of stocking rates on the leaf area index under high grazing intensity and a floristic composition with a predominance of tussocks under low grazing intensity. Vegetation indices can be used for distinguishing moderate grazing intensity from low and high intensities. The average EVI values can discriminate moderate grazing intensity during any season, and the NDVI values can discriminate moderate grazing intensity during spring and winter.

  4. Above- and Belowground Biomass Allocation in Shrub Biomes across the Northeast Tibetan Plateau

    Science.gov (United States)

    Yang, Yuanhe; Yang, Lucun; Zhou, Guoying

    2016-01-01

    Biomass partitioning has been explored across various biomes. However, the strategies of allocation in plants still remain contentious. This study investigated allocation patterns of above- and belowground biomass at the community level, using biomass survey from the Tibetan Plateau. We explored above- and belowground biomass by conducting three consecutive sampling campaigns across shrub biomes on the northeast Tibetan Plateau during 2011–2013. We then documented the above-ground biomass (AGB), below-ground biomass (BGB) and root: shoot ratio (R/S) and the relationships between R/S and environment factors using data from 201 plots surveyed from 67 sites. We further examined relationships between above-ground and below-ground biomass across various shrub types. Our results indicated that the median values of AGB, BGB, and R/S in Tibetan shrub were 1102.55, 874.91 g m-2, and 0.85, respectively. R/S showed significant trend with mean annual precipitation (MAP), while decreased with mean annual temperature (MAT). Reduced major axis analysis indicated that the slope of the log-log relationship between above- and belowground biomass revealed a significant difference from 1.0 over space, supporting the optimal hypothesis. Interestingly, the slopes of the allometric relationship between log AGB and log BGB differed significantly between alpine and desert shrub. Our findings supported the optimal theory of above- and belowground biomass partitioning in Tibetan shrub, while the isometric hypothesis for alpine shrub at the community level. PMID:27119379

  5. The deforestation story: testing for anthropogenic origins of Africa's flammable grassy biomes.

    Science.gov (United States)

    Bond, William; Zaloumis, Nicholas P

    2016-06-05

    Africa has the most extensive C4 grassy biomes of any continent. They are highly flammable accounting for greater than 70% of the world's burnt area. Much of Africa's savannas and grasslands occur in climates warm enough and wet enough to support closed forests. The combination of open grassy systems and the frequent fires they support have long been interpreted as anthropogenic artefacts caused by humans igniting frequent fires. True grasslands, it was believed, would be restricted to climates too dry or too cold to support closed woody vegetation. The idea that higher-rainfall savannas are anthropogenic and that fires are of human origin has led to initiatives to 'reforest' Africa's open grassy systems paid for by carbon credits under the assumption that the net effect of converting these system to forests would sequester carbon, reduce greenhouse gases and mitigate global warming. This paper reviews evidence for the antiquity of African grassy ecosystems and for the fires that they sustain. Africa's grassy biomes and the fires that maintain them are ancient and there is no support for the idea that humans caused large-scale deforestation. Indicators of old-growth grasslands are described. These can help distinguish secondary grasslands suitable for reforestation from ancient grasslands that should not be afforested.This article is part of the themed issue 'The interaction of fire and mankind'. © 2016 The Author(s).

  6. Contribution to the discussions on the origin of the cerrado biome: Brazilian savanna

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    MHO. Pinheiro

    Full Text Available Theories that attempt to explain the origin of the cerrado biome are mostly based on the isolated action of three major factors: climate, fire and soil. Another factor that has been mentioned is that of human interference. We hypothesise that the evolutionary origin of this biome resulted from the complex interaction of climate, fire and soil, with climate being the triggering agent of this assumed interaction. Fire, as well as acid and dystrophic soils, would be factors involved in the selection of savanna species throughout climatic events, during the Tertiary and the Quaternary, e.g. Pliocene and Pleistocene. The genesis of the physiognomies that would give rise to cerrado sensu lato, rather than forest formations, could have occurred due to the strong pressure exerted by the reduction in water availability, and the selection of the species adapted to the new conditions imposed by the environment. The characteristics of cerrado sensu lato soil, originated from edaphic impoverishment caused by lixiviation and successive past fires, would remain, even after hydric availability increased following the Pleistocene glaciations.

  7. NDVI and meteorological data as indicators of the Pampa biome natural grasslands growth

    Directory of Open Access Journals (Sweden)

    Denise Cybis Fontana

    2018-04-01

    Full Text Available ABSTRACT The present study aimed to characterize the dynamics of NDVI and meteorological conditions, relating both to the annual dynamics of biomass accumulation in natural pastures of the Pampa biome as a way of subsidizing growth modeling. Forage accumulation rate data from a long-term experiment, NDVI data from the MODIS images, and meteorological data measured at the surface were used. We verify that the agrometeorological element associated to the accumulation of forage in the natural grasslands is different according to the season, which is typical of the subtropical climate. Winter is the critical season for livestock production due to the lower forage accumulation rate and lower values of NDVI, conditioned by the decrease of solar radiation and air temperature. In the summer, the limiting factor to forage accumulation is the hydric condition. It was also verified that the variability in the growth of grasslands can be associated with the ENSO phenomenon, being the El Niño favorable and the La Niña unfavorable, especially in the spring-summer period. Considering the verified associations, spectral indices combined with agrometeorological elements are recommended to the adjustment of models of forage accumulation in the Pampa biome natural grasslands.

  8. Feedbacks between land cover and climate changes in the Brazilian Amazon and Cerrado biomes

    Science.gov (United States)

    Coe, M. T.; Silverio, D. V.; Bustamante, M.; Macedo, M.; Shimbo, J.; Brando, P. M.

    2016-12-01

    An estimated 20% of Amazon forests and 45% of Cerrado savannas have been cleared to make way for the expansion of croplands and pasturelands in Brazil. Although deforestation rates have decreased or remained steady over the last decade, the cumulative area deforested continues to grow in both biomes. These land-use transitions are expected to influence regional climate by reducing evapotranspiration (ET), increasing land surface temperatures (LST), and ultimately reducing regional precipitation. Here we present results from spatial analyses to quantify the impact of land-use transitions on the regional climate of the Amazon-Cerrado agricultural frontier. The analyses combine satellite observations and model outputs from the MODIS dataset. Results from the southeastern Amazon indicate that transitions from forest to pasture or cropland decreased mean annual ET (by 24% and 32%, respectively) and increased LST (by 4.2°C and 6.4°C). Preliminary results from the Cerrado indicate that transitions from woody savannas to pasture or cropland also result in substantial reductions in mean annual ET (23% and 20%, respectively) and increases in LST (by 1.6°C in both cases). These results reinforce the need to better understand how land-use change at regional scales may alter climate by changing ecosystem properties (beyond carbon stocks and fluxes). It is important to evaluate these responses across different biomes, particularly in tropical regions under increasing deforestation pressure.

  9. Cities as Novel Biomes;Recognizing Urban Ecosystem Services as Anthropogenic

    Directory of Open Access Journals (Sweden)

    Stephanie ePincetl

    2015-12-01

    Full Text Available Urban Ecosystem Science is now an established science, arising along side the historic shift of humans to becoming in majority urban dwellers. In this Perspective I suggest there is a need to develop a new framework for UES as embedded in distinct urban biomes that can be classified by city-type and typologized. UES are largely the artifact of human decision making from what to plant where, to determining the urban infrastructure type in which UES will be placed. Developing urban typologies by climate zone, level of development, size and history will better enable the understanding of UES. I attempt to show the rise of the importance of nature, and of urban nature following the development of industrial city, and the importance of human intent in creating these urban ecosystems over time. If humans choose to manage cities through increasing UES, this will require coupled shifts, the shift in rules and regulations, goals and processes and shifts in urban form, infrastructure and function – socio-technical-ecological changes – driven by human decision-making. Such efforts will vary widely by city -- by urban biome.

  10. A biome-scale assessment of the impact of invasive alien plants on ecosystem services in South Africa.

    Science.gov (United States)

    van Wilgen, B W; Reyers, B; Le Maitre, D C; Richardson, D M; Schonegevel, L

    2008-12-01

    This paper reports an assessment of the current and potential impacts of invasive alien plants on selected ecosystem services in South Africa. We used data on the current and potential future distribution of 56 invasive alien plant species to estimate their impact on four services (surface water runoff, groundwater recharge, livestock production and biodiversity) in five terrestrial biomes. The estimated reductions in surface water runoff as a result of current invasions were >3000 million m(3) (about 7% of the national total), most of which is from the fynbos (shrubland) and grassland biomes; the potential reductions would be more than eight times greater if invasive alien plants were to occupy the full extent of their potential range. Impacts on groundwater recharge would be less severe, potentially amounting to approximately 1.5% of the estimated maximum reductions in surface water runoff. Reductions in grazing capacity as a result of current levels of invasion amounted to just over 1% of the potential number of livestock that could be supported. However, future impacts could increase to 71%. A 'biodiversity intactness index' (the remaining proportion of pre-modern populations) ranged from 89% to 71% for the five biomes. With the exception of the fynbos biome, current invasions have almost no impact on biodiversity intactness. Under future levels of invasion, however, these intactness values decrease to around 30% for the savanna, fynbos and grassland biomes, but to even lower values (13% and 4%) for the two karoo biomes. Thus, while the current impacts of invasive alien plants are relatively low (with the exception of those on surface water runoff), the future impacts could be very high. While the errors in these estimates are likely to be substantial, the predicted impacts are sufficiently large to suggest that there is serious cause for concern.

  11. Structural development and web service based sensitivity analysis of the Biome-BGC MuSo model

    Science.gov (United States)

    Hidy, Dóra; Balogh, János; Churkina, Galina; Haszpra, László; Horváth, Ferenc; Ittzés, Péter; Ittzés, Dóra; Ma, Shaoxiu; Nagy, Zoltán; Pintér, Krisztina; Barcza, Zoltán

    2014-05-01

    Studying the greenhouse gas exchange, mainly the carbon dioxide sink and source character of ecosystems is still a highly relevant research topic in biogeochemistry. During the past few years research focused on managed ecosystems, because human intervention has an important role in the formation of the land surface through agricultural management, land use change, and other practices. In spite of considerable developments current biogeochemical models still have uncertainties to adequately quantify greenhouse gas exchange processes of managed ecosystem. Therefore, it is an important task to develop and test process-based biogeochemical models. Biome-BGC is a widely used, popular biogeochemical model that simulates the storage and flux of water, carbon, and nitrogen between the ecosystem and the atmosphere, and within the components of the terrestrial ecosystems. Biome-BGC was originally developed by the Numerical Terradynamic Simulation Group (NTSG) of University of Montana (http://www.ntsg.umt.edu/project/biome-bgc), and several other researchers used and modified it in the past. Our research group developed Biome-BGC version 4.1.1 to improve essentially the ability of the model to simulate carbon and water cycle in real managed ecosystems. The modifications included structural improvements of the model (e.g., implementation of multilayer soil module and drought related plant senescence; improved model phenology). Beside these improvements management modules and annually varying options were introduced and implemented (simulate mowing, grazing, planting, harvest, ploughing, application of fertilizers, forest thinning). Dynamic (annually varying) whole plant mortality was also enabled in the model to support more realistic simulation of forest stand development and natural disturbances. In the most recent model version separate pools have been defined for fruit. The model version which contains every former and new development is referred as Biome-BGC MuSo (Biome

  12. Análisis comparativo de distintas toolkits para el reconocimiento biométrico de personas mediante voz

    OpenAIRE

    Ruíz, Silvia; Miranda, Ernesto; Herlein, Mauro; Etchart, Graciela; Alvez, Carlos E.

    2017-01-01

    El objetivo de este trabajo es realizar un análisis comparativo de distintas toolkits para el reconocimiento biométrico de personas mediante voz. Hoy en día los sistemas de identificación de personas se han convertido en una necesidad para la sociedad. A medida que avanza la tecnología y la aplicación de la misma en entornos tanto de ocio como de seguridad, la evolución en desarrollo biométrico es muy grande. Los sistemas de identificación o verificación tradicionales (tarjetas o claves) se h...

  13. Improved clonality detection in B-cell lymphoma using a semi-nested modification of the BIOMED-2 PCR assay for IGH rearrangement: A paraffin-embedded tissue study.

    Science.gov (United States)

    Sakamoto, Yuma; Masaki, Ayako; Aoyama, Satsuki; Han, Shusen; Saida, Kosuke; Fujii, Kana; Takino, Hisashi; Murase, Takayuki; Iida, Shinsuke; Inagaki, Hiroshi

    2017-09-01

    The BIOMED-2 PCR protocol for targeting the IGH gene is widely employed for detecting clonality in B-cell malignancies. Unfortunately, the detection of clonality with this method is not very sensitive when paraffin sections are used as a DNA source. To increase the sensitivity, we devised a semi-nested modification of a JH consensus primer. The clonality detection rates of three assays were compared: the standard BIOMED-2, BIOMED-2 assay followed by BIOMED-2 re-amplification, and BIOMED-2 assay followed by semi-nested BIOMED-2. We tested more than 100 cases using paraffin-embedded tissues of various B-cell lymphomas, and found that the clonality detection rates with the above three assays were 63.9%, 79.6%, and 88.0%, respectively. While BIOMED-2 re-amplification was significantly more sensitive than the standard BIOMED-2, the semi-nested BIOMED-2 was significantly more sensitive than both the standard BIOMED-2 and BIOMED-2 re-amplification. An increase in sensitivity was observed in all lymphoma subtypes examined. In conclusion, tumor clonality may be detected in nearly 90% of B-cell lymphoma cases with semi-nested BIOMED-2. This ancillary assay may be useful when the standard BIOMED-2 fails to detect clonality in histopathologically suspected B-cell lymphomas. © 2017 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.

  14. Social networks in education of health professionals in bosnia and herzegovina - the role of pubmed/medline in improvement of medical sciences.

    Science.gov (United States)

    Masic, Izet; Sivic, Suad

    2011-12-01

    Social network is a social structure made up of individuals and organizations that represent "nodes", and they are associated with one or more types of interdependency; such as: friendship, common interests, work, knowledge, prestige and many other interests. Beginning with the late twentieth and early twenty-first century, the Internet was a significant additional tool in the education of teenagers. Later, it takes more and more significant role in educating students and professionals. The aim of this paper is to investigate, to what extent and how effectively the Internet is used today. In addition, more specifically, this paper will research the implications of the well-known social networks in education of students and health professionals in Bosnia and Herzegovina (B&H). We compared the ratio of using Medline, as the largest biomedical data base system for spreading medical information, as basics for health education at biomedical faculties at five universities in B&H. According to data from the CRA (i.e. Communications Regulatory Agency) in B&H, in 2010, there were 522,364 internet access accounts, with about 2 million Internet users, representing about 52% of the total population. The Internet users' preference is dominated by the users of fast broadband access (e.g. xDSL) with 42.8%, and elsewhere, still with dialup access, with 25.2%. The results showed that only 11.6% of professors use Facebook type of social network, 49.3% of them have a profile on BiomedExperts scientific social network and 79% have available articles in the largest biomedical literature database MEDLINE. Students are also frequent users of general social networks and educational clips from You Tube, which they prefer to utilize considerably more than the other types of professionals. Students rarely use the facilities of professional social networks, because they contain mainly data and information needed for further, postgraduate professional education. In our research, we analized

  15. Impact of SciELO and MEDLINE indexing on submissions to Jornal de Pediatria.

    Science.gov (United States)

    Blank, Danilo; Buchweitz, Claudia; Procianoy, Renato S

    2005-01-01

    To evaluate the impact of SciELO and MEDLINE indexing on the number of articles submitted to Jornal de Pediatria. Analysis of total article submission, submission of articles from foreign countries and acceptance figures in the following periods: stage I - pre-website (Jan 2000-Mar 2001); stage II - website (Apr 2001-Jul 2002); stage III - SciELO (Aug 2002-Aug 2003); stage IV - MEDLINE (Sep 2003-Dec 2004). There was a significant trend toward linear increase in the number of submissions along the study period (p = 0.009). The number of manuscripts submitted in stages I through IV was 184, 240, 297, and 482, respectively. The number of submissions was similar in stages I and II (p = 0.148), but statistically higher in Stage III (p SciELO indexing was associated with an increase in Brazilian manuscript submissions to Jornal de Pediatria, whereas MEDLINE indexing led to an increase in both Brazilian and foreign submissions.

  16. The MedlinePlus public user interface: studies of design challenges and opportunities

    Science.gov (United States)

    Marill, Jennifer L.; Miller, Naomi; Kitendaugh, Paula

    2006-01-01

    Question: What are the challenges involved in designing, modifying, and improving a major health information portal that serves over sixty million page views a month? Setting: MedlinePlus, the National Library of Medicine's (NLM's) consumer health Website, is examined. Method: Challenges are presented as six “studies,” which describe selected design issues and how NLM staff resolved them. Main Result: Improving MedlinePlus is an iterative process. Changes in the public user interface are ongoing, reflecting Web design trends, usability testing recommendations, user survey results, new technical requirements, and the need to grow the site in an orderly way. Conclusion: Testing and analysis should accompany Website design modifications. New technologies may enhance a site but also introduce problems. Further modifications to MedlinePlus will be informed by the experiences described here. PMID:16404467

  17. Plant litter dynamics in the forest-stream interface: precipitation is a major control across tropical biomes.

    Science.gov (United States)

    Tonin, Alan M; Gonçalves, José F; Bambi, Paulino; Couceiro, Sheyla R M; Feitoza, Lorrane A M; Fontana, Lucas E; Hamada, Neusa; Hepp, Luiz U; Lezan-Kowalczuk, Vânia G; Leite, Gustavo F M; Lemes-Silva, Aurea L; Lisboa, Leonardo K; Loureiro, Rafael C; Martins, Renato T; Medeiros, Adriana O; Morais, Paula B; Moretto, Yara; Oliveria, Patrícia C A; Pereira, Evelyn B; Ferreira, Lidiane P; Pérez, Javier; Petrucio, Mauricio M; Reis, Deusiano F; S Rezende, Renan; Roque, Nadia; Santos, Luiz E P; Siegloch, Ana E; Tonello, Gabriela; Boyero, Luz

    2017-09-07

    Riparian plant litter is a major energy source for forested streams across the world and its decomposition has repercussions on nutrient cycling, food webs and ecosystem functioning. However, we know little about plant litter dynamics in tropical streams, even though the tropics occupy 40% of the Earth's land surface. Here we investigated spatial and temporal (along a year cycle) patterns of litter inputs and storage in multiple streams of three tropical biomes in Brazil (Atlantic forest, Amazon forest and Cerrado savanna), predicting major differences among biomes in relation to temperature and precipitation regimes. Precipitation explained most of litter inputs and storage, which were generally higher in more humid biomes (litterfall: 384, 422 and 308 g m -2 y -1 , storage: 55, 113 and 38 g m -2 , on average in Atlantic forest, Amazon and Cerrado, respectively). Temporal dynamics varied across biomes in relation to precipitation and temperature, with uniform litter inputs but seasonal storage in Atlantic forest streams, seasonal inputs in Amazon and Cerrado streams, and aseasonal storage in Amazon streams. Our findings suggest that litter dynamics vary greatly within the tropics, but point to the major role of precipitation, which contrasts with the main influence of temperature in temperate areas.

  18. Tropical rainforest biome of Biosphere 2. Structure, composition and results of the first 2 years of operation

    Energy Technology Data Exchange (ETDEWEB)

    Leigh, Linda S. [Systems Ecology and Energy Analysis Program, Department of Environmental Engineering Sciences, University of Florida, Gainesville, FL (United States); Burgess, Tony; Marino, Bruno D.V.; Wei, Yong Dan [Biosphere 2 Center, Inc. P.O. Box 689, Oracle, AZ (United States)

    1999-06-01

    The tropical rainforest biome in the Biosphere 2 mesocosm was managed with rainfall and temperature conditions to simulate a natural rainforest typical of the new world tropics. The establishment of the biome was based on the introduction of excessive numbers of species allowing self-organization of an ecologically unique rainforest. Over 282 species of plants from rainforest areas were planted within the topographically diverse rainforest biome (area of 1900 m{sup 2}, volume of 35,000 m{sup 3}), just before the Biosphere 2 closure in 1991. Approximately 61% of these species survived when counted in 1993, representing a plant species richness reduction to 172 species in 0.19 hectare. Rank order graphs show that a high diversity community resulted not unlike insular rainforests. The plants of the rainforest mesocosm, however, grew under anomalous conditions of soil (amended desert grassland soil), atmospheric composition (CO{sub 2} up to 4500 ppm by volume (ppmv)) and rainwater composition (high salinity and nutrients). Stem growth rates of a dominant canopy tree, Cecropia, were up to four times higher but had reduced diameter at breast height compared to natural counterparts. Human intervention in plant succession was also an important factor in shaping the ecology of the rainforest biome of Biosphere 2

  19. Adapting the Biome-BGC Model to New Zealand Pastoral Agriculture: Climate Change and Land-Use Change

    Science.gov (United States)

    Keller, E. D.; Baisden, W. T.; Timar, L.

    2011-12-01

    We have adapted the Biome-BGC model to make climate change and land-use scenario estimates of New Zealand's pasture production in 2020 and 2050, with comparison to a 2005 baseline. We take an integrated modelling approach with the aim of enabling the model's use for policy assessments across broadly related issues such as climate change mitigation and adaptation, land-use change, and greenhouse gas projections. The Biome-BGC model is a biogeochemical model that simulates carbon, water, and nitrogen cycles in terrestrial ecosystems. We introduce two new 'ecosystems', sheep/beef and dairy pasture, within the existing structure of the Biome-BGC model and calibrate its ecophysiological parameters against pasture clipping data from diverse sites around New Zealand to form a baseline estimate of total New Zealand pasture production. Using downscaled AR4 climate projections, we construct mid- and upper-range climate change scenarios in 2020 and 2050. We produce land-use change scenarios in the same years by combining the Biome-BGC model with the Land Use in Rural New Zealand (LURNZ) model. The LURNZ model uses econometric approaches to predict future land-use change driven by changes in net profits driven by expected pricing, including the introduction of an emission trading system. We estimate the relative change in national pasture production from our 2005 baseline levels for both sheep/beef and dairy systems under each scenario.

  20. Scaling net ecosystem production and net biome production over a heterogeneous region in the Western United States

    Science.gov (United States)

    D.P. Turner; W.D. Ritts; B.E. Law; W.B. Cohen; Z. Yan; T. Hudiburg; J.L. Campbell; M. Duane

    2007-01-01

    Bottom-up scaling of net ecosystem production (NEP) and net biome production (NBP) was used to generate a carbon budget for a large heterogeneous region (the state of Oregon, 2.5x105 km2 ) in the Western United States. Landsat resolution (30 m) remote sensing provided the basis for mapping land cover and disturbance history...

  1. A remarkable finding that suggests the existence of a new groundwater biome based on chemoautotrophic resources, named

    Directory of Open Access Journals (Sweden)

    Ştefan Negrea

    2009-01-01

    Full Text Available An important work of subterranean biology, signed by Francis Dov Por, Ophel: a groundwater biome based on chemoautotrophic resources. The global significance of the Ayyalon cave finds, Israel is presented and discussed in the present paper. The subject is a remarkable discovery suggesting the existence of a new aquatic subterranean biome autonomous energy based the author calls Ophel, the Hebrew word for “darkness” and “netherworld”. For F.D. Por, this biome links different marine chemosynthetic ecosystems in a global biospheric entity. Finally, F.D. POR hypothesizes on the existence of three overlapped biospheres: the bacteriosphere in the depths of the planet’s crust, which does not require light or oxygen; the aphotic, subterranean deuterobiosphere, formed of bacterial chemosynthesis based eukaryotes and limited-supplied dissolved oxygen from above-ground; the above-ground eubiosphere, based on aerobic photosynthesis. I would like to emphasize that, at my suggestion, Prof. Dr. F.D. Por participated at the 18th International Symposium of Biospeleology from Cluj-Napoca (Romania at 10th to 15th July 2006 where he mentioned for the first time orally some data on the Ayyalon Cave and the Ophel biome.

  2. Physiology of Saccharomyces cerevisiae strains isolated from Brazilian biomes: new insights into biodiversity and industrial applications

    DEFF Research Database (Denmark)

    Beato, Felipe B.; Bergdahl, Basti; Rosa, Carlos A.

    2016-01-01

    Fourteen indigenous Saccharomyces cerevisiae strains isolated from the barks of three tree species located in the Atlantic Rain Forest and Cerrado biomes in Brazil were genetically and physiologically compared to laboratory strains and to strains from the Brazilian fuel ethanol industry. Although...

  3. Modeling impacts of human footprint and soil variability on the potential distribution of invasive plant species in different biomes

    Science.gov (United States)

    Wan, Ji-Zhong; Wang, Chun-Jing; Yu, Fei-Hai

    2017-11-01

    Human footprint and soil variability may be important in shaping the spread of invasive plant species (IPS). However, until now, there is little knowledge on how human footprint and soil variability affect the potential distribution of IPS in different biomes. We used Maxent modeling to project the potential distribution of 29 IPS with wide distributions and long introduction histories in China based on various combinations of climatic correlates, soil characteristics and human footprint. Then, we evaluated the relative importance of each type of environmental variables (climate, soil and human footprint) as well as the difference in range and similarity of the potential distribution of IPS between different biomes. Human footprint and soil variables contributed to the prediction of the potential distribution of IPS, and different types of biomes had varying responses and degrees of impacts from the tested variables. Human footprint and soil variability had the highest tendency to increase the potential distribution of IPS in Montane Grasslands and Shrublands. We propose to integrate the assessment in impacts of human footprint and soil variability on the potential distribution of IPS in different biomes into the prevention and control of plant invasion.

  4. A method to determine warm and cool steppe biomes from pollen data; application to the Mediterranean and Kazakhstan regions

    NARCIS (Netherlands)

    Tarasov, PE; Cheddadi, R; Guiot, J; Bottema, S; Peyron, O; Belmonte, J; Ruiz-Sanchez, [No Value; Saadi, F; Brewer, S

    1998-01-01

    An objective method for the assignment of pollen spectra to appropriate biomes has been published recently. The aim of this paper is to improve the distinction between warm and cool steppes, thus refining vegetation and climate reconstruction, particularly during the Last Glacial Maximum. A set of

  5. The global extent and determinants of savanna and forest as alternative biome states.

    Science.gov (United States)

    Staver, A Carla; Archibald, Sally; Levin, Simon A

    2011-10-14

    Theoretically, fire-tree cover feedbacks can maintain savanna and forest as alternative stable states. However, the global extent of fire-driven discontinuities in tree cover is unknown, especially accounting for seasonality and soils. We use tree cover, climate, fire, and soils data sets to show that tree cover is globally discontinuous. Climate influences tree cover globally but, at intermediate rainfall (1000 to 2500 millimeters) with mild seasonality (less than 7 months), tree cover is bimodal, and only fire differentiates between savanna and forest. These may be alternative states over large areas, including parts of Amazonia and the Congo. Changes in biome distributions, whether at the cost of savanna (due to fragmentation) or forest (due to climate), will be neither smooth nor easily reversible.

  6. BOREAS RSS-8 BIOME-BGC SSA Simulation of Annual Water and Carbon Fluxes

    Science.gov (United States)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Kimball, John

    2000-01-01

    The BOREAS RSS-8 team performed research to evaluate the effect of seasonal weather and landcover heterogeneity on boreal forest regional water and carbon fluxes using a process-level ecosystem model, BIOME-BGC, coupled with remote sensing-derived parameter maps of key state variables. This data set contains derived maps of landcover type and crown and stem biomass as model inputs to determine annual evapotranspiration, gross primary production, autotrophic respiration, and net primary productivity within the BOREAS SSA-MSA, at a 30-m spatial resolution. Model runs were conducted over a 3-year period from 1994-1996; images are provided for each of those years. The data are stored in binary image format. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  7. Overview on Environmental Comprehensive Management System Established in Imitation of Biome

    Institute of Scientific and Technical Information of China (English)

    李如燕; 孙可伟

    2004-01-01

    Environmental comprehensive management system, called "the bionic community", can be established in imitation of biome, which can transform the wastes generated in a certain field into the raw materials of other field. The establishment of the bionic community includes two aspects, i.e. , the matching technique and the management system. The main matching technique is the preparation of composite materials made of various wastes.This new kind of material can be divided into four types: polymer matrix, silicate matrix, metal matrix and carbon matrix (or ceramic matrix). The environmental comprehensive management system is formed by organizing a transtrades joint-management business entity with the products of composite material made of wastes at the core.

  8. Biométria de frutos e sementes de Luetzelburgia auriculata (Allemão Ducke

    Directory of Open Access Journals (Sweden)

    Roberto Ferreira Barroso

    2016-12-01

    Full Text Available A Caatinga apresenta uma grande diversidade de espécies vegetais, dentre elas Luetzelburgia auriculata é uma das espécies predominantes no bioma, desempenhando papel fundamental para o ecossistema local. Este trabalho objetivou descrever as características biométricas de frutos e sementes de Luetzelburgia auriculata.  Para a descrição das características da semente foram coletados 200 frutos e 200 sementes de plantas nativas do município de Santa Helena, Paraíba. As amostras foram encaminhadas ao Laboratório de Nutrição Mineral de Plantas do Centro de Saúde e Tecnologia Rural de Universidade Federal de Campina Grande para a realização das devidas aferições biométricas. Os frutos foram analisado pelo comprimento, espessura superior, mediana e inferior; largura superior, mediana e inferior. Para as sementes, foram analisados comprimento, espessura e a largura. Verificou-se que o comprimento dos frutos variou de 50,7 a 98,2 cm, a espessura de 6,00 a 17 mm e largura variando de 12,4 a 21,8 mm. Em relação às sementes, 46% se enquadraram na classe de comprimento com intervalo de 19,9 a 20,8 mm. A espécie Luetzelburgia auriculata apresentam variabilidade nas características biométricas de frutos e sementesBiometrics of fruit and seeds of Luetzelburgia auriculata (Allemão DuckeAbstract: The Caatinga presents a great diversity of plant species, among them the woodpecker (Luetzelburgia auriculata (Allemao Ducke. is one of the predominant species in the biome, playing a fundament al role for the local ecosystem. This work aimed to describe the biometric characteristics of fruits and seeds of Pau de Pedra. For the description of the characteristics of the Luetzelburgia auriculata (Allemão Ducke seed, 200 fruits and 200 seeds of native plants of the municipality of Santa Helena, Paraíba state were collected for biometry and seed mass. Afterwards they were packed in plastic bags and properly identified and taken to Laboratório de

  9. Autenticación mediante parámetros biométricos

    OpenAIRE

    Pastor Navarro, Ricard

    2017-01-01

    En les pàgines següents s’explicarà el procés seguit per la realització d’aquest treball de final de grau, en el que es pretén substituir, en un programa de gestió de contrasenyes, la contrasenya mestre per paràmetres biomètrics, concretament el reconeixement facial. Per a complir amb aquest objectiu s’utilitzaran alguns algoritmes de visió per computador extrets de les llibreries de OpenCV. El sistema final agafarà imatges de l’usuari i fent la comprovació del usuari decidint si ha de donar ...

  10. Genetic Divergence in Eucalyptus camaldulensis Progenies in the Savanna Biome in Mato Grosso, Brazil.

    Directory of Open Access Journals (Sweden)

    Reginaldo Brito da Costa

    Full Text Available Assessing the parental genetic differences and their subsequent prediction of progeny performance is an important first step to assure the efficiency of any breeding program. In this study, we estimate the genetic divergence in Eucalyptus camaldulensis based on the morphological traits of 132 progenies grown in a savanna biome. Thus, a field experiment was performed using a randomized block design and five replications to compare divergences in total height, commercial height, diameter at breast height, stem form and survival rate at 48 months. Tocher's clustering method was performed using the Mahalanobis and Euclidian distances. The Mahalanobis distance seemed more reliable for the assessed parameters and clustered all of the progenies into fourteen major groups. The most similar progenies (86 accessions were clustered into Group I, while the most dissimilar (1 progeny represented Group XIV. The divergence analysis indicated that promising crosses could be made between progenies allocated in different groups for high genetic divergence and for favorable morphological traits.

  11. Tundra biome research in Alaska: the structure and function of cold-dominated ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.; West, G.C.

    1970-11-01

    The objective of the Tundra Biome Program is to acquire a basic understanding of tundra, both alpine and arctic, and taiga. Collectively these are referred to as the cold-dominated ecosystems. The program's broad objectives are threefold: To develop a predictive understanding of how the wet arctic tundra ecosystem operates, particularly as exemplified in the Barrow, Alaska, area; to obtain the necessary data base from the variety of cold-dominated ecosystem types represented in the United States, so that their behavior can be modeled and simulated, and the results compared with similar studies underway in other circumpolar countries; to bring basic environmental knowledge to bear on problems of degradation, maintenance, and restoration of the temperature-sensitive and cold-dominated tundra/taiga ecosystems. (GRA)

  12. Microbial Community Profile and Water Quality in a Protected Area of the Caatinga Biome.

    Science.gov (United States)

    Lopes, Fabyano Alvares Cardoso; Catão, Elisa Caldeira Pires; Santana, Renata Henrique; Cabral, Anderson de Souza; Paranhos, Rodolfo; Rangel, Thiago Pessanha; de Rezende, Carlos Eduardo; Edwards, Robert A; Thompson, Cristiane C; Thompson, Fabiano L; Kruger, Ricardo Henrique

    2016-01-01

    The Caatinga is a semi-arid biome in northeast Brazil. The Paraguaçú River is located in the Caatinga biome, and part of its course is protected by the National Park of Chapada Diamantina (PNCD). In this study we evaluated the effect of PNCD protection on the water quality and microbial community diversity of this river by analyzing water samples obtained from points located inside and outside the PNCD in both wet and dry seasons. Results of water quality analysis showed higher levels of silicate, ammonia, particulate organic carbon, and nitrite in samples from the unprotected area compared with those from protected areas. Pyrosequencing of the 16S rRNA genes revealed that Burkholderiales was abundant in samples from all three sites during both seasons and was represented primarily by the genus Polynucleobacter and members of the Comamonadaceae family (e.g., genus Limnohabitans). During the dry season, the unprotected area showed a higher abundance of Flavobacterium sp. and Arthrobacter sp., which are frequently associated with the presence and/or degradation of arsenic and pesticide compounds. In addition, genes that appear to be related to agricultural impacts on the environment, as well as those involved in arsenic and cadmium resistance, copper homeostasis, and propanediol utilization, were detected in the unprotected areas by metagenomic sequencing. Although PNCD protection improves water quality, agricultural activities around the park may affect water quality within the park and may account for the presence of bacteria capable of pesticide degradation and assimilation, evidencing possible anthropogenic impacts on the Caatinga.

  13. Trans-biome diversity in Australian grass-specialist lizards (Diplodactylidae: Strophurus).

    Science.gov (United States)

    Laver, Rebecca J; Nielsen, Stuart V; Rosauer, Dan F; Oliver, Paul M

    2017-10-01

    Comparisons of biodiversity patterns within lineages that occur across major climate gradients and biomes, can provide insights into the relative roles that lineage history, landscape and climatic variation, and environmental change have played in shaping regional biotas. In Australia, while there has been extensive research into the origins and patterns of diversity in the Australian Arid Zone (AAZ), how diversity is distributed across this biome and the Australian Monsoonal Tropics (AMT) to the north, has been less studied. We compared the timing and patterns of diversification across this broad aridity gradient in a clade of lizards (Strophurus: phasmid geckos) that only occur in association with a unique Australian radiation of sclerophyllous grasses (Triodia: spinifex). Our results indicate that overall genetic diversity is much higher, older and more finely geographically structured within the AMT, including distantly related clades endemic to the sandstone escarpments of the Kimberley and Arnhem Plateau. Niche modelling analyses also suggest that the distribution of taxa in the AMT is more strongly correlated with variation in topographic relief than in the AAZ. The two broad patterns that we recovered - (i) lineage endemism increases as latitude decreases, and (ii) endemism is tightly correlated to rocky regions - parallel and corroborate other recent studies of habitat generalists and specialised saxicoline lineages occurring across these same regions. Early Miocene diversification estimates also suggest that, soon after Triodia grasses colonised Australia and began to diversify in the Miocene, phasmid geckos with Gondwanan ancestry shifted into these grasses, and have subsequently remained closely associated with this unique vegetation type. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Biome-scale nitrogen fixation strategies selected by climatic constraints on nitrogen cycle.

    Science.gov (United States)

    Sheffer, Efrat; Batterman, Sarah A; Levin, Simon A; Hedin, Lars O

    2015-11-23

    Dinitrogen fixation by plants (in symbiosis with root bacteria) is a major source of new nitrogen for land ecosystems(1). A long-standing puzzle(2) is that trees capable of nitrogen fixation are abundant in nitrogen-rich tropical forests, but absent or restricted to early successional stages in nitrogen-poor extra-tropical forests. This biome-scale pattern presents an evolutionary paradox(3), given that the physiological cost(4) of nitrogen fixation predicts the opposite pattern: fixers should be out-competed by non-fixers in nitrogen-rich conditions, but competitively superior in nitrogen-poor soils. Here we evaluate whether this paradox can be explained by the existence of different fixation strategies in tropical versus extra-tropical trees: facultative fixers (capable of downregulating fixation(5,6) by sanctioning mutualistic bacteria(7)) are common in the tropics, whereas obligate fixers (less able to downregulate fixation) dominate at higher latitudes. Using a game-theoretic approach, we assess the ecological and evolutionary conditions under which these fixation strategies emerge, and examine their dependence on climate-driven differences in the nitrogen cycle. We show that in the tropics, transient soil nitrogen deficits following disturbance and rapid tree growth favour a facultative strategy and the coexistence of fixers and non-fixers. In contrast, sustained nitrogen deficits following disturbance in extra-tropical forests favour an obligate fixation strategy, and cause fixers to be excluded in late successional stages. We conclude that biome-scale differences in the abundance of nitrogen fixers can be explained by the interaction between individual plant strategies and climatic constraints on the nitrogen cycle over evolutionary time.

  15. Soil, water, and nutrient losses from management alternatives for degraded pasture in Brazilian Atlantic Rainforest biome.

    Science.gov (United States)

    Rocha Junior, Paulo Roberto da; Andrade, Felipe Vaz; Mendonça, Eduardo de Sá; Donagemma, Guilherme Kangussú; Fernandes, Raphael Bragança Alves; Bhattharai, Rabin; Kalita, Prasanta Kumar

    2017-04-01

    The objective of this study was to evaluate sediment, water and nutrient losses from different pasture managements in the Atlantic Rainforest biome. A field study was carried out in Alegre Espiríto Santo, Brazil, on a Xanthic Ferralsol cultivated with braquiaria (Brachiaria brizantha). The six pasture managements studied were: control (CON), chisel (CHI), fertilizer (FER), burned (BUR), plowing and harrowing (PH), and integrated crop-livestock (iCL). Runoff and sediment samples were collected and analyzed for calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P) and organic carbon contents. Soil physical attributes and above and below biomass were also evaluated. The results indicated that higher water loss was observed for iCL (129.90mm) and CON (123.25mm) managements, and the sediment losses were higher for CON (10.24tha -1 ) and BUR (5.20tha -1 ) managements when compared to the other managements. Majority of the nutrients losses occurred in dissolved fraction (99% of Ca, 99% of Mg, 96% of K, and 65% of P), whereas a significant fraction of organic carbon (80%) loss occurred in a particulate form. Except for P, other nutrients (Ca, Mg and K) and organic carbon losses were higher in coarse sediment compared to fine sediment. The greater losses of sediment, organic carbon, and nutrients were observed for CON followed by BUR management (plosses from various practices, to reduce pasture degradation, farmers should adopt edaphic practices by applying lime and fertilize to improve pasture growth and soil cover, and reducing soil erosion in the hilly Brazilian Atlantic Rainforest biome. Copyright © 2016. Published by Elsevier B.V.

  16. Married...with Food Allergies | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... this page please turn Javascript on. Feature: Food Allergies Married...with Food Allergies Past Issues / Spring 2011 Table of Contents Photo: ... life together and a common problem—severe food allergies. NIH MedlinePlus magazine’s Naomi Miller caught up with ...

  17. Parkinson's Disease Research at NIH | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... of this page please turn JavaScript on. Feature: Parkinson's Disease Parkinson's Disease Research at NIH Past Issues / Winter 2014 ... areas of its research: MedlinePlus . medlineplus.gov . Type "Parkinson's disease" in the Search box. NIHSeniorHealth —Parkinson's Disease ...

  18. The development of search filters for adverse effects of surgical interventions in medline and Embase.

    Science.gov (United States)

    Golder, Su; Wright, Kath; Loke, Yoon Kong

    2018-03-31

    Search filter development for adverse effects has tended to focus on retrieving studies of drug interventions. However, a different approach is required for surgical interventions. To develop and validate search filters for medline and Embase for the adverse effects of surgical interventions. Systematic reviews of surgical interventions where the primary focus was to evaluate adverse effect(s) were sought. The included studies within these reviews were divided randomly into a development set, evaluation set and validation set. Using word frequency analysis we constructed a sensitivity maximising search strategy and this was tested in the evaluation and validation set. Three hundred and fifty eight papers were included from 19 surgical intervention reviews. Three hundred and fifty two papers were available on medline and 348 were available on Embase. Generic adverse effects search strategies in medline and Embase could achieve approximately 90% relative recall. Recall could be further improved with the addition of specific adverse effects terms to the search strategies. We have derived and validated a novel search filter that has reasonable performance for identifying adverse effects of surgical interventions in medline and Embase. However, we appreciate the limitations of our methods, and recommend further research on larger sample sizes and prospective systematic reviews. © 2018 The Authors Health Information and Libraries Journal published by John Wiley & Sons Ltd on behalf of Health Libraries Group.

  19. High school peer tutors teach MedlinePlus: a model for Hispanic outreach*

    Science.gov (United States)

    Warner, Debra G.; Olney, Cynthia A.; Wood, Fred B.; Hansen, Lucille; Bowden, Virginia M.

    2005-01-01

    Objectives: The objective was to introduce the MedlinePlus Website to the predominantly Hispanic residents of the Lower Rio Grande Valley region of Texas by partnering with a health professions magnet high school (known as Med High). Methods: Community assessment was used in the planning stages and included pre-project focus groups with students and teachers. Outreach methods included peer tutor selection, train-the-trainer sessions, school and community outreach, and pre- and posttests of MedlinePlus training sessions. Evaluation methods included Web statistics; end-of-project interviews; focus groups with students, faculty, and librarians; and end-of-project surveys of students and faculty. Results: Four peer tutors reached more than 2,000 people during the project year. Students and faculty found MedlinePlus to be a useful resource. Faculty and librarians developed new or revised teaching methods incorporating MedlinePlus. The project enhanced the role of school librarians as agents of change at Med High. The project continues on a self-sustaining basis. Conclusions: Using peer tutors is an effective way to educate high school students about health information resources and, through the students, to reach families and community members. PMID:15858628

  20. Use of the critical incident technique to evaluate the impact of MEDLINE

    International Nuclear Information System (INIS)

    Wilson, S.R.; Starr-Schneidkraut, N.; Cooper, M.D.

    1989-01-01

    The NLM has an ongoing responsibility to assess the extent to which its information products and services support the requirements of its users. This enables the Library to craft ever more responsive systems that capitalize on the latest advances in information and computer technology and, when necessary, to modify existing systems whose performance may no longer be optimal or consistent with the functions intended. The importance of this requirement was underscored in the recent report of the Outreach Planning Panel to the NLM Board of regents. A fundamental concern is the need to identify the impact of MEDLINE-derived information--i.e., does the use of MEDLINE ''make a difference''? In what ways is it used, and with what effect? In particular, is information retrieved from MEDLINE used successfully by health professionals to support medical decision-making and patient care? Previous efforts to address this question have been limited to the collection of available anecdotal reports. Traditional survey methodology, with pre-defined response categories, while used effectively to determine general areas in which MEDLINE information is used, is not well suited to developing a detailed understanding of user motivation, behavior, and resulting consequences. 8 refs., 6 figs., 2 tab

  1. A novel algorithm for analyzing drug-drug interactions from MEDLINE literature.

    Science.gov (United States)

    Lu, Yin; Shen, Dan; Pietsch, Maxwell; Nagar, Chetan; Fadli, Zayd; Huang, Hong; Tu, Yi-Cheng; Cheng, Feng

    2015-11-27

    Drug-drug interaction (DDI) is becoming a serious clinical safety issue as the use of multiple medications becomes more common. Searching the MEDLINE database for journal articles related to DDI produces over 330,000 results. It is impossible to read and summarize these references manually. As the volume of biomedical reference in the MEDLINE database continues to expand at a rapid pace, automatic identification of DDIs from literature is becoming increasingly important. In this article, we present a random-sampling-based statistical algorithm to identify possible DDIs and the underlying mechanism from the substances field of MEDLINE records. The substances terms are essentially carriers of compound (including protein) information in a MEDLINE record. Four case studies on warfarin, ibuprofen, furosemide and sertraline implied that our method was able to rank possible DDIs with high accuracy (90.0% for warfarin, 83.3% for ibuprofen, 70.0% for furosemide and 100% for sertraline in the top 10% of a list of compounds ranked by p-value). A social network analysis of substance terms was also performed to construct networks between proteins and drug pairs to elucidate how the two drugs could interact.

  2. Usefulness of systematic review search strategies in finding child health systematic reviews in MEDLINE

    NARCIS (Netherlands)

    Boluyt, Nicole; Tjosvold, Lisa; Lefebvre, Carol; Klassen, Terry P.; Offringa, Martin

    2008-01-01

    OBJECTIVE: To determine the sensitivity and precision of existing search strategies for retrieving child health systematic reviews in MEDLINE using PubMed. DESIGN: Filter (diagnostic) accuracy study. We identified existing search strategies for systematic reviews, combined them with a filter that

  3. The role of plant functional trade-offs for biodiversity changes and biome shifts under scenarios of global climatic change

    Directory of Open Access Journals (Sweden)

    B. Reu

    2011-05-01

    Full Text Available The global geographic distribution of biodiversity and biomes is determined by species-specific physiological tolerances to climatic constraints. Current vegetation models employ empirical bioclimatic relationships to predict present-day vegetation patterns and to forecast biodiversity changes and biome shifts under climatic change. In this paper, we consider trade-offs in plant functioning and their responses under climatic changes to forecast and explain changes in plant functional richness and shifts in biome geographic distributions.

    The Jena Diversity model (JeDi simulates plant survival according to essential plant functional trade-offs, including ecophysiological processes such as water uptake, photosynthesis, allocation, reproduction and phenology. We use JeDi to quantify changes in plant functional richness and biome shifts between present-day and a range of possible future climates from two SRES emission scenarios (A2 and B1 and seven global climate models using metrics of plant functional richness and functional identity.

    Our results show (i a significant loss of plant functional richness in the tropics, (ii an increase in plant functional richness at mid and high latitudes, and (iii a pole-ward shift of biomes. While these results are consistent with the findings of empirical approaches, we are able to explain them in terms of the plant functional trade-offs involved in the allocation, metabolic and reproduction strategies of plants. We conclude that general aspects of plant physiological tolerances can be derived from functional trade-offs, which may provide a useful process- and trait-based alternative to bioclimatic relationships. Such a mechanistic approach may be particularly relevant when addressing vegetation responses to climatic changes that encounter novel combinations of climate parameters that do not exist under contemporary climate.

  4. The GAAS metagenomic tool and its estimations of viral and microbial average genome size in four major biomes.

    Science.gov (United States)

    Angly, Florent E; Willner, Dana; Prieto-Davó, Alejandra; Edwards, Robert A; Schmieder, Robert; Vega-Thurber, Rebecca; Antonopoulos, Dionysios A; Barott, Katie; Cottrell, Matthew T; Desnues, Christelle; Dinsdale, Elizabeth A; Furlan, Mike; Haynes, Matthew; Henn, Matthew R; Hu, Yongfei; Kirchman, David L; McDole, Tracey; McPherson, John D; Meyer, Folker; Miller, R Michael; Mundt, Egbert; Naviaux, Robert K; Rodriguez-Mueller, Beltran; Stevens, Rick; Wegley, Linda; Zhang, Lixin; Zhu, Baoli; Rohwer, Forest

    2009-12-01

    Metagenomic studies characterize both the composition and diversity of uncultured viral and microbial communities. BLAST-based comparisons have typically been used for such analyses; however, sampling biases, high percentages of unknown sequences, and the use of arbitrary thresholds to find significant similarities can decrease the accuracy and validity of estimates. Here, we present Genome relative Abundance and Average Size (GAAS), a complete software package that provides improved estimates of community composition and average genome length for metagenomes in both textual and graphical formats. GAAS implements a novel methodology to control for sampling bias via length normalization, to adjust for multiple BLAST similarities by similarity weighting, and to select significant similarities using relative alignment lengths. In benchmark tests, the GAAS method was robust to both high percentages of unknown sequences and to variations in metagenomic sequence read lengths. Re-analysis of the Sargasso Sea virome using GAAS indicated that standard methodologies for metagenomic analysis may dramatically underestimate the abundance and importance of organisms with small genomes in environmental systems. Using GAAS, we conducted a meta-analysis of microbial and viral average genome lengths in over 150 metagenomes from four biomes to determine whether genome lengths vary consistently between and within biomes, and between microbial and viral communities from the same environment. Significant differences between biomes and within aquatic sub-biomes (oceans, hypersaline systems, freshwater, and microbialites) suggested that average genome length is a fundamental property of environments driven by factors at the sub-biome level. The behavior of paired viral and microbial metagenomes from the same environment indicated that microbial and viral average genome sizes are independent of each other, but indicative of community responses to stressors and environmental conditions.

  5. The GAAS metagenomic tool and its estimations of viral and microbial average genome size in four major biomes.

    Directory of Open Access Journals (Sweden)

    Florent E Angly

    2009-12-01

    Full Text Available Metagenomic studies characterize both the composition and diversity of uncultured viral and microbial communities. BLAST-based comparisons have typically been used for such analyses; however, sampling biases, high percentages of unknown sequences, and the use of arbitrary thresholds to find significant similarities can decrease the accuracy and validity of estimates. Here, we present Genome relative Abundance and Average Size (GAAS, a complete software package that provides improved estimates of community composition and average genome length for metagenomes in both textual and graphical formats. GAAS implements a novel methodology to control for sampling bias via length normalization, to adjust for multiple BLAST similarities by similarity weighting, and to select significant similarities using relative alignment lengths. In benchmark tests, the GAAS method was robust to both high percentages of unknown sequences and to variations in metagenomic sequence read lengths. Re-analysis of the Sargasso Sea virome using GAAS indicated that standard methodologies for metagenomic analysis may dramatically underestimate the abundance and importance of organisms with small genomes in environmental systems. Using GAAS, we conducted a meta-analysis of microbial and viral average genome lengths in over 150 metagenomes from four biomes to determine whether genome lengths vary consistently between and within biomes, and between microbial and viral communities from the same environment. Significant differences between biomes and within aquatic sub-biomes (oceans, hypersaline systems, freshwater, and microbialites suggested that average genome length is a fundamental property of environments driven by factors at the sub-biome level. The behavior of paired viral and microbial metagenomes from the same environment indicated that microbial and viral average genome sizes are independent of each other, but indicative of community responses to stressors and

  6. Developing optimal search strategies for detecting clinically sound prognostic studies in MEDLINE: an analytic survey

    Directory of Open Access Journals (Sweden)

    Haynes R Brian

    2004-06-01

    Full Text Available Abstract Background Clinical end users of MEDLINE have a difficult time retrieving articles that are both scientifically sound and directly relevant to clinical practice. Search filters have been developed to assist end users in increasing the success of their searches. Many filters have been developed for the literature on therapy and reviews but little has been done in the area of prognosis. The objective of this study is to determine how well various methodologic textwords, Medical Subject Headings, and their Boolean combinations retrieve methodologically sound literature on the prognosis of health disorders in MEDLINE. Methods An analytic survey was conducted, comparing hand searches of journals with retrievals from MEDLINE for candidate search terms and combinations. Six research assistants read all issues of 161 journals for the publishing year 2000. All articles were rated using purpose and quality indicators and categorized into clinically relevant original studies, review articles, general papers, or case reports. The original and review articles were then categorized as 'pass' or 'fail' for methodologic rigor in the areas of prognosis and other clinical topics. Candidate search strategies were developed for prognosis and run in MEDLINE – the retrievals being compared with the hand search data. The sensitivity, specificity, precision, and accuracy of the search strategies were calculated. Results 12% of studies classified as prognosis met basic criteria for scientific merit for testing clinical applications. Combinations of terms reached peak sensitivities of 90%. Compared with the best single term, multiple terms increased sensitivity for sound studies by 25.2% (absolute increase, and increased specificity, but by a much smaller amount (1.1% when sensitivity was maximized. Combining terms to optimize both sensitivity and specificity achieved sensitivities and specificities of approximately 83% for each. Conclusion Empirically derived

  7. PubMed had a higher sensitivity than Ovid-MEDLINE in the search for systematic reviews.

    Science.gov (United States)

    Katchamart, Wanruchada; Faulkner, Amy; Feldman, Brian; Tomlinson, George; Bombardier, Claire

    2011-07-01

    To compare the performance of Ovid-MEDLINE vs. PubMed for identifying randomized controlled trials of methotrexate (MTX) in patients with rheumatoid arthritis (RA). We created search strategies for Ovid-MEDLINE and PubMed for a systematic review of MTX in RA. Their performance was evaluated using sensitivity, precision, and number needed to read (NNR). Comparing searches in Ovid-MEDLINE vs. PubMed, PubMed retrieved more citations overall than Ovid-MEDLINE; however, of the 20 citations that met eligibility criteria for the review, Ovid-MEDLINE retrieved 17 and PubMed 18. The sensitivity was 85% for Ovid-MEDLINE vs. 90% for PubMed, whereas the precision and NNR were comparable (precision: 0.881% for Ovid-MEDLINE vs. 0.884% for PubMed and NNR: 114 for Ovid-MEDLINE vs. 113 for PubMed). In systematic reviews of RA, PubMed has higher sensitivity than Ovid-MEDLINE with comparable precision and NNR. This study highlights the importance of well-designed database-specific search strategies. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Vida saudável versus vida aprimorada: tecnologias biomédicas, processos de subjetivação e aprimoramento

    Directory of Open Access Journals (Sweden)

    Fabíola Rohden

    Full Text Available Resumo Fenômenos contemporâneos como um crescimento significativo dos campos da medicina sexual e da medicina estética exigem novas investigações empíricas e também aprofundamento de determinados debates teóricos. No contexto das últimas décadas, ganham relevo formas de subjetivação centradas no investimento pessoal via transformações corporais, nas quais o consumo de artefatos biomédicos considerados inovadores torna-se central. Em função da produção de questões advindas desse campo, este artigo discute criticamente alguns vetores conceituais. Categorias analíticas como biomedicalização, farmacologização, modos de subjetivação e aprimoramento são centrais para dar conta de entender os processos em questão. Na mesma direção, é preciso considerar a importância de problematizar as fronteiras entre os investimentos associados à manutenção da saúde e aqueles motivados pelo aprimoramento de si.

  9. Sensibility and time heterogeneity of Biome-BGC model parameters%Biome-BGC模型参数的敏感性和时间异质性

    Institute of Scientific and Technical Information of China (English)

    刘秋雨; 张廷龙; 孙睿; 王博闻; 叶欣欣; 李一哲

    2017-01-01

    生态过程模型为研究陆表生态系统水、碳、氮等物质的循环提供了一种有效的手段.模型与数据同化结合可建立模拟与观测之间的桥梁,同时提高模型与观测两种方法揭示地表真实状况的有效性.但模型参数的特性,将直接影响到模型模拟及数据同化的精度.传统观念认为,生态过程模型参数在相同植被类型条件下是固定不变的,但近期研究已开始关注其时空异质性.本文以Biome-BGC模型为例,利用美国哈佛森林Environmental Monitoring Site (EMS)通量观测站的相关数据,对哈佛森林地区水、碳通量进行模拟.首先对模型参数进行敏感性分析;然后应用模拟退火算法,构造目标函数,使待优化的敏感参数在合理阈值范围内不断变动反复迭代,获取逐月的最优参数值;通过引入变异系数,对敏感参数的时间异质性进行分析.结果表明:生态过程模型参数最优值并非常量,而会随时间表现出异质性,而且各参数时间异质性大小差异显著.文中对Biome-BGC模型的敏感参数按时间异质性大小划分了相应的等级.研究结果有助于加深对生态过程模型参数特性的认识,为参数的合理取值及动态优化提供思路与依据,有助于进一步提高模型模拟和数据同化的精度与效率.%Ecological process model provides an effective way for studying water,carbon and nitrogen cycles of terrestrial ecosystem.The combination of the model and data assimilation could build a link between observation and simulation,which improves the effectiveness of model and observation methods to reveal the real state of land surface,but the accuracy of simulation and assimilation is directly affected by model parameters.Parameters are constants in traditional opinion;however,some current studies have focused on the time-space heterogeneity of parameters.In this paper,we used Harvard Forest Environmental Monitoring Site (EMS) data to simulate

  10. Operationalizing Semantic Medline for meeting the information needs at point of care

    Science.gov (United States)

    Rastegar-Mojarad, Majid; Li, Dingcheng; Liu, Hongfang

    2015-01-01

    Scientific literature is one of the popular resources for providing decision support at point of care. It is highly desirable to bring the most relevant literature to support the evidence-based clinical decision making process. Motivated by the recent advance in semantically enhanced information retrieval, we have developed a system, which aims to bring semantically enriched literature, Semantic Medline, to meet the information needs at point of care. This study reports our work towards operationalizing the system for real time use. We demonstrate that the migration of a relational database implementation to a NoSQL (Not only SQL) implementation significantly improves the performance and makes the use of Semantic Medline at point of care decision support possible. PMID:26306259

  11. An IR-Based Approach Utilizing Query Expansion for Plagiarism Detection in MEDLINE.

    Science.gov (United States)

    Nawab, Rao Muhammad Adeel; Stevenson, Mark; Clough, Paul

    2017-01-01

    The identification of duplicated and plagiarized passages of text has become an increasingly active area of research. In this paper, we investigate methods for plagiarism detection that aim to identify potential sources of plagiarism from MEDLINE, particularly when the original text has been modified through the replacement of words or phrases. A scalable approach based on Information Retrieval is used to perform candidate document selection-the identification of a subset of potential source documents given a suspicious text-from MEDLINE. Query expansion is performed using the ULMS Metathesaurus to deal with situations in which original documents are obfuscated. Various approaches to Word Sense Disambiguation are investigated to deal with cases where there are multiple Concept Unique Identifiers (CUIs) for a given term. Results using the proposed IR-based approach outperform a state-of-the-art baseline based on Kullback-Leibler Distance.

  12. Operationalizing Semantic Medline for meeting the information needs at point of care.

    Science.gov (United States)

    Rastegar-Mojarad, Majid; Li, Dingcheng; Liu, Hongfang

    2015-01-01

    Scientific literature is one of the popular resources for providing decision support at point of care. It is highly desirable to bring the most relevant literature to support the evidence-based clinical decision making process. Motivated by the recent advance in semantically enhanced information retrieval, we have developed a system, which aims to bring semantically enriched literature, Semantic Medline, to meet the information needs at point of care. This study reports our work towards operationalizing the system for real time use. We demonstrate that the migration of a relational database implementation to a NoSQL (Not only SQL) implementation significantly improves the performance and makes the use of Semantic Medline at point of care decision support possible.

  13. Modeling the grazing effect on dry grassland carbon cycling with modified Biome-BGC grazing model

    Science.gov (United States)

    Luo, Geping; Han, Qifei; Li, Chaofan; Yang, Liao

    2014-05-01

    Identifying the factors that determine the carbon source/sink strength of ecosystems is important for reducing uncertainty in the global carbon cycle. Arid grassland ecosystems are a widely distributed biome type in Xinjiang, Northwest China, covering approximately one-fourth the country's land surface. These grasslands are the habitat for many endemic and rare plant and animal species and are also used as pastoral land for livestock. Using the modified Biome-BGC grazing model, we modeled carbon dynamics in Xinjiang for grasslands that varied in grazing intensity. In general, this regional simulation estimated that the grassland ecosystems in Xinjiang acted as a net carbon source, with a value of 0.38 Pg C over the period 1979-2007. There were significant effects of grazing on carbon dynamics. An over-compensatory effect in net primary productivity (NPP) and vegetation carbon (C) stock was observed when grazing intensity was lower than 0.40 head/ha. Grazing resulted in a net carbon source of 23.45 g C m-2 yr-1, which equaled 0.37 Pg in Xinjiang in the last 29 years. In general, grazing decreased vegetation C stock, while an increasing trend was observed with low grazing intensity. The soil C increased significantly (17%) with long-term grazing, while the soil C stock exhibited a steady trend without grazing. These findings have implications for grassland ecosystem management as it relates to carbon sequestration and climate change mitigation, e.g., removal of grazing should be considered in strategies that aim to increase terrestrial carbon sequestrations at local and regional scales. One of the greatest limitations in quantifying the effects of herbivores on carbon cycling is identifying the grazing systems and intensities within a given region. We hope our study emphasizes the need for large-scale assessments of how grazing impacts carbon cycling. Most terrestrial ecosystems in Xinjiang have been affected by disturbances to a greater or lesser extent in the past

  14. Future projections of fire danger in Brazilian biomes in the 21st century

    Science.gov (United States)

    Libonati, Renata; Silva, Patrícia; DaCamara, Carlos; Bastos, Ana

    2016-04-01

    In the global context, Brazil is one of the regions more severely affected by fire occurrences, with important consequences in the global CO2 balance, the state of the Amazon forest and the ecological diversity of the region. Brazil is also one of the few regions experiencing a raise in annual mean temperature above 2.5o during the 20th century, which may further increase between 2o and 7o until 2100 and, likely, be accompanied by a decrease in precipitation [1]. As the fire occurrence and severity largely depends on these two variables, it is worth assessing the evolution of fire danger for the coming decades. In order to obtain a detailed characterization of the future fire patterns in the different biomes of Brazil, we use outputs from a regional-downscaling of the EC-Earth climate model at 0.44 degrees spatial resolution for two future scenarios, an intermediate (RCP4.5) and a more severe (RCP8.5) one. We use a fire danger index specifically developed for the Brazilian climate and biome characteristics, the IFR from INPE. This index relies on values of maximum temperature, accumulated precipitation over different periods, minimum relative humidity and vegetation cover to estimate the likelihood of fire occurrence. We find a systematic increase of the days with critical fire risk, which is more pronounced in RCP8.5 and mostly affects months when fire activity takes place. Temperature increase is the most determinant factor for the increase in fire danger in the dry regions of savannah and shrubland, a result to be expected as fuel is already very dry. [1] Collins, M., R. Knutti, J. Arblaster, J.-L. Dufresne, T. Fichefet, P. Friedlingstein, X. Gao, W.J. Gutowski, T. Johns, G. Krinner, M. Shongwe, C. Tebaldi, A.J. Weaver and M. Wehner, 2013: Long-term Climate Change: Projections, Commitments and Irreversibility. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on

  15. Structure of Drosophilidae Assemblage (Insecta, Diptera in Pampa Biome (São Luiz Gonzaga, RS

    Directory of Open Access Journals (Sweden)

    Jean Lucas Poppe

    2012-01-01

    Full Text Available The Brazilian Pampa (the southernmost end of the country is currently a highly modified environment because of increasing agricultural activities. In many places, only small parts of grasslands remain inside an agricultural landscape. Drosophilidae (Diptera have been widely used as a potential bioindicators to monitor the effects of anthropogenic changes in natural environments. However, the fauna of Drosophilidae in the Pampa Biome from natural and disturbed environments, still remains largely unknown. The present study represents one of the first attempts to fill this gap, showing results from monthly collections in the municipality of São Luiz Gonzaga (28º24'28"S, 54º57'39"W, in the Brazilian Pampa. A species inventory was carried out in two contrasting environments, an urban zone and a forest remnant (rural zone. In both areas banana-baited traps were used to capture adult drosophilids. The identification was made using external morphology and male terminalia. In total, 13,379 drosophilids were analyzed (rural zone: N = 8,812 and Sobs = 25; urban zone: N = 4,567 and Sobs = 16. In the present study, 16 (60% out of 26 species were found exclusively or preferentially in the forest. The period of highest richness was between the months of June to November (roughly winter and spring, and the period of lowest richness was from December to May (roughly summer and autumn. An analysis of cluster by the Coefficient of Jaccard showed that species composition slightly changes when the period of the year with higher temperatures (from January to May is compared with the period with lower temperatures (from June to October. The species abundances were also highly affected by seasonality, as revealed by the Morisita Index, since the samples clustered into similar groups in consecutive periods and in the same season, showing the seasonal preference of some species. The time component was a determinant in the diversity of the assemblage, surpassing the

  16. A short guide to peer-reviewed, MEDLINE-indexed complementary and alternative medicine journals.

    Science.gov (United States)

    Morgan, Sherry; Littman, Lynn; Palmer, Christina; Singh, Gurneet; LaRiccia, Patrick J

    2012-01-01

    Complementary and alternative medicine (CAM) comprises a multitude of disciplines, for example, acupuncture, ayurvedic medicine, biofeedback, herbal medicine, and homeopathic medicine. While research on CAM interventions has increased and the CAM literature has proliferated since the mid-1990s, a number of our colleagues have expressed difficulties in deciding where to publish CAM articles. In response, we created a short guide to peer-reviewed MEDLINE-indexed journals that publish CAM articles. We examined numerous English-language sources to identify titles that met our criteria, whether specific to or overlapping CAM. A few of the resources in which we found the journal titles that we included are Alternative Medicine Foundation, American Holistic Nurses Association, CINAHL/Nursing Database, Journal Citation Reports database, MEDLINE, PubMed, and Research Council for Complementary Medicine. We organized the 69 selected titles for easy use by creating 2 user-friendly tables, one listing titles in alphabetical order and one listing them in topical categories. A few examples of the topical categories are Acupuncture, CAM (general), Chinese Medicine, Herbal/Plant/Phytotherapy, Neuroscience/Psychology, Nursing/Clinical Care. Our study is the first to list general CAM journals, specialty CAM journals, and overlapping mainstream journals that are peer reviewed, in English, and indexed in MEDLINE. Our goal was to assist both authors seeking publication and mainstream journal editors who receive an overabundance of publishable articles but must recommend that authors seek publication elsewhere due to space and priority issues. Publishing in journals indexed by and included in MEDLINE (or PubMed) ensures that citations to articles will be found easily. Copyright © 2012 Lippincott Williams & Wilkins.

  17. Evaluation of Term Ranking Algorithms for Pseudo-Relevance Feedback in MEDLINE Retrieval.

    Science.gov (United States)

    Yoo, Sooyoung; Choi, Jinwook

    2011-06-01

    The purpose of this study was to investigate the effects of query expansion algorithms for MEDLINE retrieval within a pseudo-relevance feedback framework. A number of query expansion algorithms were tested using various term ranking formulas, focusing on query expansion based on pseudo-relevance feedback. The OHSUMED test collection, which is a subset of the MEDLINE database, was used as a test corpus. Various ranking algorithms were tested in combination with different term re-weighting algorithms. Our comprehensive evaluation showed that the local context analysis ranking algorithm, when used in combination with one of the reweighting algorithms - Rocchio, the probabilistic model, and our variants - significantly outperformed other algorithm combinations by up to 12% (paired t-test; p algorithm pairs, at least in the context of the OHSUMED corpus. Comparative experiments on term ranking algorithms were performed in the context of a subset of MEDLINE documents. With medical documents, local context analysis, which uses co-occurrence with all query terms, significantly outperformed various term ranking methods based on both frequency and distribution analyses. Furthermore, the results of the experiments demonstrated that the term rank-based re-weighting method contributed to a remarkable improvement in mean average precision.

  18. Knowledge production status of Iranian researchers in the gastric cancer area: based on the medline database.

    Science.gov (United States)

    Ghojazadeh, Morteza; Naghavi-Behzad, Mohammad; Nasrolah-Zadeh, Raheleh; Bayat-Khajeh, Parvaneh; Piri, Reza; Mirnia, Keyvan; Azami-Aghdash, Saber

    2014-01-01

    Scientometrics is a useful method for management of financial and human resources and has been applied many times in medical sciences during recent years. The aim of this study was to investigate the status of science production by Iranian scientists in the gastric cancer field based on the Medline database. In this descriptive-cross sectional study Iranian science production concerning gastric cancer during 2000-2011 was investigated based on Medline. After two stages of searching, 121 articles were found, then we reviewed publication date, authors names, journal title, impact factor (IF), and cooperation coefficient between researchers. SPSS.19 was used for statistical analysis. There was a significant increase in published articles about gastric cancer by Iranian researchers in Medline database during 2006-2011. Mean cooperation coefficient between researchers was 6.14±3.29 person per article. Articles of this field were published in 19 countries and 56 journals. Those basex in Thailand, England, and America had the most published Iranian articles. Tehran University of Medical Sciences and Mohammadreza Zali had the most outstanding role in publishing scientific articles. According to results of this study, improving cooperation of researchers in conducting research and scientometric studies about other fields may have an important role in increasing both quality and quantity of published studies.

  19. Dialysis search filters for PubMed, Ovid MEDLINE, and Embase databases.

    Science.gov (United States)

    Iansavichus, Arthur V; Haynes, R Brian; Lee, Christopher W C; Wilczynski, Nancy L; McKibbon, Ann; Shariff, Salimah Z; Blake, Peter G; Lindsay, Robert M; Garg, Amit X

    2012-10-01

    Physicians frequently search bibliographic databases, such as MEDLINE via PubMed, for best evidence for patient care. The objective of this study was to develop and test search filters to help physicians efficiently retrieve literature related to dialysis (hemodialysis or peritoneal dialysis) from all other articles indexed in PubMed, Ovid MEDLINE, and Embase. A diagnostic test assessment framework was used to develop and test robust dialysis filters. The reference standard was a manual review of the full texts of 22,992 articles from 39 journals to determine whether each article contained dialysis information. Next, 1,623,728 unique search filters were developed, and their ability to retrieve relevant articles was evaluated. The high-performance dialysis filters consisted of up to 65 search terms in combination. These terms included the words "dialy" (truncated), "uremic," "catheters," and "renal transplant wait list." These filters reached peak sensitivities of 98.6% and specificities of 98.5%. The filters' performance remained robust in an independent validation subset of articles. These empirically derived and validated high-performance search filters should enable physicians to effectively retrieve dialysis information from PubMed, Ovid MEDLINE, and Embase.

  20. Psoriasis Doesn't Slow Down Texan Brian LaFoy | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... willing to do. I'm one of the lucky ones." Find Out More National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) MedlinePlus-Psoriasis Clinical Trials Search Psoriasis Spring 2017 Issue: Volume 12 Number 1 Page 22 MedlinePlus Subscribe Magazine Information Contact ...

  1. Uso de bases de datos bibliográficas por investigadores biomédicos latinoamericanos hispanoparlantes: estudio transversal The use of bibliographic databases by Spanish-speaking Latin American biomedical researchers: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Edgar Guillermo Ospina

    2005-04-01

    Full Text Available OBJETIVO: Caracterizar cómo los profesionales biomédicos hispanoparlantes de América Latina acceden a y utilizan las bases de datos bibliográficas. MÉTODOS: A partir de una búsqueda en MEDLINE se identificaron 2 515 artículos publicados entre agosto de 2002 y agosto de 2003 por autores de Argentina, Bolivia, Chile, Colombia, Costa Rica, Cuba, Ecuador, Guatemala, Honduras, México, Nicaragua, Panamá, Paraguay, Perú, Uruguay y Venezuela. La búsqueda se limitó a referencias de las ciencias básicas y clínicas y de la medicina social. Se envió una encuesta por correo electrónico a los autores que efectuaron su investigación y residían en alguno de los países estudiados. En la encuesta se exploraron el área de desempeño del investigador (ciencias básicas, clínicas o salud pública, el nivel de destreza en la utilización de las bases de datos, la frecuencia y el tipo de acceso a las bases de datos más empleadas, el impacto de la carencia de los textos completos en el momento de escribir un manuscrito y la vía mediante la cual los encuestados solían conseguir el texto completo de los artículos. RESULTADOS: Se enviaron en total 586 mensajes con la encuesta y se recibieron 185 respuestas (32%. Las bases de datos más utilizadas para obtener información biomédica fueron MEDLINE (34,1%, los motores de búsqueda generales (Google, Yahoo! y Alta Vista (15,9%, las revistas en línea (9,8%, BIREME-LILACS (6,0%, BioMedNet (5,4%, las bases de datos del Centro para el Control y la Prevención de Enfermedades (CDC de los Estados Unidos (5,2% y la Biblioteca Cochrane (4,9%. De los encuestados, 64% indicaron tener habilidades medias o avanzadas en la utilización de MEDLINE. Sin embargo, 72% no utilizaban ni conocían los MeSH ("medical subject headings", términos estandarizados fijados por la Biblioteca Nacional de Medicina de los Estados Unidos para hacer búsquedas en bases de datos bio-médicas. La frecuencia de las consultas a las

  2. Plant litter dynamics in the forest-stream interface: precipitation is a major control across tropical biomes

    OpenAIRE

    Tonin, Alan M.; Gon?alves, Jos? F.; Bambi, Paulino; Couceiro, Sheyla R. M.; Feitoza, Lorrane A. M.; Fontana, Lucas E.; Hamada, Neusa; Hepp, Luiz U.; Lezan-Kowalczuk, V?nia G.; Leite, Gustavo F. M.; Lemes-Silva, Aurea L.; Lisboa, Leonardo K.; Loureiro, Rafael C.; Martins, Renato T.; Medeiros, Adriana O.

    2017-01-01

    Riparian plant litter is a major energy source for forested streams across the world and its decomposition has repercussions on nutrient cycling, food webs and ecosystem functioning. However, we know little about plant litter dynamics in tropical streams, even?though the tropics occupy 40% of the Earth?s land surface. Here we investigated spatial and temporal (along a year cycle) patterns of litter inputs and storage in multiple streams of three tropical biomes in Brazil (Atlantic forest, Ama...

  3. [Parameter sensitivity of simulating net primary productivity of Larix olgensis forest based on BIOME-BGC model].

    Science.gov (United States)

    He, Li-hong; Wang, Hai-yan; Lei, Xiang-dong

    2016-02-01

    Model based on vegetation ecophysiological process contains many parameters, and reasonable parameter values will greatly improve simulation ability. Sensitivity analysis, as an important method to screen out the sensitive parameters, can comprehensively analyze how model parameters affect the simulation results. In this paper, we conducted parameter sensitivity analysis of BIOME-BGC model with a case study of simulating net primary productivity (NPP) of Larix olgensis forest in Wangqing, Jilin Province. First, with the contrastive analysis between field measurement data and the simulation results, we tested the BIOME-BGC model' s capability of simulating the NPP of L. olgensis forest. Then, Morris and EFAST sensitivity methods were used to screen the sensitive parameters that had strong influence on NPP. On this basis, we also quantitatively estimated the sensitivity of the screened parameters, and calculated the global, the first-order and the second-order sensitivity indices. The results showed that the BIOME-BGC model could well simulate the NPP of L. olgensis forest in the sample plot. The Morris sensitivity method provided a reliable parameter sensitivity analysis result under the condition of a relatively small sample size. The EFAST sensitivity method could quantitatively measure the impact of simulation result of a single parameter as well as the interaction between the parameters in BIOME-BGC model. The influential sensitive parameters for L. olgensis forest NPP were new stem carbon to new leaf carbon allocation and leaf carbon to nitrogen ratio, the effect of their interaction was significantly greater than the other parameter' teraction effect.

  4. Comment on Chiesi et al. (2011): “Use of BIOME-BGC to simulate Mediterranean forest carbon stocks”

    OpenAIRE

    Eastaugh CS

    2011-01-01

    The mechanistic forest growth model BIOME-BGC utilizes a “spin-up” procedure to estimate site parameters for forests in a steady-state condition, as they may have been expected to be prior to anthropogenic influence. Forests in this condition have no net growth, as living biomass accumulation is balanced by mortality. To simulate current ecosystems it is necessary to reset the model to reflect a forest of the correct development stage. The alternative approach of simply post-adjus...

  5. Soil Loss Vulnerability in an Agricultural Catchment in the Atlantic Forest Biome in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Rafael Gotardo

    2016-11-01

    Full Text Available This study estimates soil loss vulnerability using field samples and spatial data in a 30 km² area in the Atlantic forest biome in southern Brazil. The anthropogenic part of the landscape consists mainly of small agricultural properties. Soil loss vulnerability was calculated using adaptations of the universal soil loss equation. The results were compared to sediment data collected during field surveys. Spatial analysis was performed using a geographical information system (GIS and fine resolution data (1 m. Both field and spatial analyses produced similar results, 5.390 tons of soil loss per year using field data and 5.691 tons per year using GIS. Using soil loss and sediment data related to the Concordia River, we estimate that of all the exported sediment 25% of the lost soil reaches the river. These data are an effective source of information for municipal administrators of the region, which consists of small agricultural catchments (dominated by small properties that comprise the regional economy. A thematic map was used to determine sub-drainage priority as information for public managers.

  6. A mesic maximum in biological water use demarcates biome sensitivity to aridity shifts.

    Science.gov (United States)

    Good, Stephen P; Moore, Georgianne W; Miralles, Diego G

    2017-12-01

    Biome function is largely governed by how efficiently available resources can be used and yet for water, the ratio of direct biological resource use (transpiration, E T ) to total supply (annual precipitation, P) at ecosystem scales remains poorly characterized. Here, we synthesize field, remote sensing and ecohydrological modelling estimates to show that the biological water use fraction (E T /P) reaches a maximum under mesic conditions; that is, when evaporative demand (potential evapotranspiration, E P ) slightly exceeds supplied precipitation. We estimate that this mesic maximum in E T /P occurs at an aridity index (defined as E P /P) between 1.3 and 1.9. The observed global average aridity of 1.8 falls within this range, suggesting that the biosphere is, on average, configured to transpire the largest possible fraction of global precipitation for the current climate. A unimodal E T /P distribution indicates that both dry regions subjected to increasing aridity and humid regions subjected to decreasing aridity will suffer declines in the fraction of precipitation that plants transpire for growth and metabolism. Given the uncertainties in the prediction of future biogeography, this framework provides a clear and concise determination of ecosystems' sensitivity to climatic shifts, as well as expected patterns in the amount of precipitation that ecosystems can effectively use.

  7. Plants of the fynbos biome harbour host species-specific bacterial communities.

    Science.gov (United States)

    Miyambo, Tsakani; Makhalanyane, Thulani P; Cowan, Don A; Valverde, Angel

    2016-08-01

    The fynbos biome in South Africa is globally recognised as a plant biodiversity hotspot. However, very little is known about the bacterial communities associated with fynbos plants, despite interactions between primary producers and bacteria having an impact on the physiology of both partners and shaping ecosystem diversity. This study reports on the structure, phylogenetic composition and potential roles of the endophytic bacterial communities located in the stems of three fynbos plants (Erepsia anceps, Phaenocoma prolifera and Leucadendron laureolum). Using Illumina MiSeq 16S rRNA sequencing we found that different subpopulations of Deinococcus-Thermus, Alphaproteobacteria, Acidobacteria and Firmicutes dominated the endophytic bacterial communities. Alphaproteobacteria and Actinobacteria were prevalent in P. prolifera, whereas Deinococcus-Thermus dominated in L. laureolum, revealing species-specific host-bacteria associations. Although a high degree of variability in the endophytic bacterial communities within hosts was observed, we also detected a core microbiome across the stems of the three plant species, which accounted for 72% of the sequences. Altogether, it seems that both deterministic and stochastic processes shaped microbial communities. Endophytic bacterial communities harboured putative plant growth-promoting bacteria, thus having the potential to influence host health and growth. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Soil-borne bacterial structure and diversity does not reflect community activity in Pampa biome.

    Science.gov (United States)

    Lupatini, Manoeli; Suleiman, Afnan Khalil Ahmad; Jacques, Rodrigo Josemar Seminoti; Antoniolli, Zaida Inês; Kuramae, Eiko Eurya; de Oliveira Camargo, Flávio Anastácio; Roesch, Luiz Fernando Würdig

    2013-01-01

    The Pampa biome is considered one of the main hotspots of the world's biodiversity and it is estimated that half of its original vegetation was removed and converted to agricultural land and tree plantations. Although an increasing amount of knowledge is being assembled regarding the response of soil bacterial communities to land use change, to the associated plant community and to soil properties, our understanding about how these interactions affect the microbial community from the Brazilian Pampa is still poor and incomplete. In this study, we hypothesized that the same soil type from the same geographic region but under distinct land use present dissimilar soil bacterial communities. To test this hypothesis, we assessed the soil bacterial communities from four land-uses within the same soil type by 454-pyrosequencing of 16S rRNA gene and by soil microbial activity analyzes. We found that the same soil type under different land uses harbor similar (but not equal) bacterial communities and the differences were controlled by many microbial taxa. No differences regarding diversity and richness between natural areas and areas under anthropogenic disturbance were detected. However, the measures of microbial activity did not converge with the 16S rRNA data supporting the idea that the coupling between functioning and composition of bacterial communities is not necessarily correlated.

  9. Local climatic conditions constrain soil yeast diversity patterns in Mediterranean forests, woodlands and scrub biome.

    Science.gov (United States)

    Yurkov, Andrey M; Röhl, Oliver; Pontes, Ana; Carvalho, Cláudia; Maldonado, Cristina; Sampaio, José Paulo

    2016-02-01

    Soil yeasts represent a poorly known fraction of the soil microbiome due to limited ecological surveys. Here, we provide the first comprehensive inventory of cultivable soil yeasts in a Mediterranean ecosystem, which is the leading biodiversity hotspot for vascular plants and vertebrates in Europe. We isolated and identified soil yeasts from forested sites of Serra da Arrábida Natural Park (Portugal), representing the Mediterranean forests, woodlands and scrub biome. Both cultivation experiments and the subsequent species richness estimations suggest the highest species richness values reported to date, resulting in a total of 57 and 80 yeast taxa, respectively. These values far exceed those reported for other forest soils in Europe. Furthermore, we assessed the response of yeast diversity to microclimatic environmental factors in biotopes composed of the same plant species but showing a gradual change from humid broadleaf forests to dry maquis. We observed that forest properties constrained by precipitation level had strong impact on yeast diversity and on community structure and lower precipitation resulted in an increased number of rare species and decreased evenness values. In conclusion, the structure of soil yeast communities mirrors the environmental factors that affect aboveground phytocenoses, aboveground biomass and plant projective cover. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. A multi-biome gap in understanding of crop and ecosystem responses to elevated CO2.

    Science.gov (United States)

    Leakey, Andrew D B; Bishop, Kristen A; Ainsworth, Elizabeth A

    2012-06-01

    A key finding from elevated [CO(2)] field experiments is that the impact of elevated [CO(2)] on plant and ecosystem function is highly dependent upon other environmental conditions, namely temperature and the availability of nutrients and soil moisture. In addition, there is significant variation in the response to elevated [CO(2)] among plant functional types, species and crop varieties. However, experimental data on plant and ecosystem responses to elevated [CO(2)] are strongly biased to economically and ecologically important systems in the temperate zone. There is a multi-biome gap in experimental data that is most severe in the tropics and subtropics, but also includes high latitudes. Physiological understanding of the environmental conditions and species found at high and low latitudes suggest they may respond differently to elevated [CO(2)] than well-studied temperate systems. Addressing this knowledge gap should be a high priority as it is vital to understanding 21st century food supply and ecosystem feedbacks on climate change. Published by Elsevier Ltd.

  11. Predicting the responsiveness of soil biodiversity to deforestation: a cross-biome study.

    Science.gov (United States)

    Crowther, Thomas W; Maynard, Daniel S; Leff, Jonathan W; Oldfield, Emily E; McCulley, Rebecca L; Fierer, Noah; Bradford, Mark A

    2014-09-01

    The consequences of deforestation for aboveground biodiversity have been a scientific and political concern for decades. In contrast, despite being a dominant component of biodiversity that is essential to the functioning of ecosystems, the responses of belowground biodiversity to forest removal have received less attention. Single-site studies suggest that soil microbes can be highly responsive to forest removal, but responses are highly variable, with negligible effects in some regions. Using high throughput sequencing, we characterize the effects of deforestation on microbial communities across multiple biomes and explore what determines the vulnerability of microbial communities to this vegetative change. We reveal consistent directional trends in the microbial community response, yet the magnitude of this vegetation effect varied between sites, and was explained strongly by soil texture. In sandy sites, the difference in vegetation type caused shifts in a suite of edaphic characteristics, driving substantial differences in microbial community composition. In contrast, fine-textured soil buffered microbes against these effects and there were minimal differences between communities in forest and grassland soil. These microbial community changes were associated with distinct changes in the microbial catabolic profile, placing community changes in an ecosystem functioning context. The universal nature of these patterns allows us to predict where deforestation will have the strongest effects on soil biodiversity, and how these effects could be mitigated. © 2014 John Wiley & Sons Ltd.

  12. SOIL ORGANIC MATTER FRACTIONS IN PRESERVED AND DISTURBED WETLANDS OF THE CERRADO BIOME

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    Ricardo Fernandes de Sousa

    2015-02-01

    Full Text Available Veredas are humid tropical ecosystems, generally associated to hydromorphic soils and a shallow water table. The soils of these ecosystems are affected by the use of the areas around these veredas. The objective of this study was to determine soil organic matter (SOM fractions in veredas adjacent to preserved (native savanna and disturbed environments (agricultural areas and pastures in the Cerrado biome. Soil samples were collected from the 0-10 and 10-20 cm layers along reference lines drawn along the relief following the upper, middle and lower positions of one of the slopes, in the direction of the draining line of the vereda. The soil analysis determined: total soil OC, total nitrogen and C:N ratio; C and N contents and C:N ratio in particulate and mineral-associated fractions (of SOM; fulvic acids, humic acids and humin fractions and ratio between humic and fulvic acids. The agricultural use around the veredas induced changes in the SOM fractions, more pronounced in the lower part of the slope. In the soil surface of this part, the OC levels in the humic substances and the particulate fraction of SOM, as well as total soil OC were reduced in the vereda next to crop fields.

  13. Introducing BASE: the Biomes of Australian Soil Environments soil microbial diversity database.

    Science.gov (United States)

    Bissett, Andrew; Fitzgerald, Anna; Meintjes, Thys; Mele, Pauline M; Reith, Frank; Dennis, Paul G; Breed, Martin F; Brown, Belinda; Brown, Mark V; Brugger, Joel; Byrne, Margaret; Caddy-Retalic, Stefan; Carmody, Bernie; Coates, David J; Correa, Carolina; Ferrari, Belinda C; Gupta, Vadakattu V S R; Hamonts, Kelly; Haslem, Asha; Hugenholtz, Philip; Karan, Mirko; Koval, Jason; Lowe, Andrew J; Macdonald, Stuart; McGrath, Leanne; Martin, David; Morgan, Matt; North, Kristin I; Paungfoo-Lonhienne, Chanyarat; Pendall, Elise; Phillips, Lori; Pirzl, Rebecca; Powell, Jeff R; Ragan, Mark A; Schmidt, Susanne; Seymour, Nicole; Snape, Ian; Stephen, John R; Stevens, Matthew; Tinning, Matt; Williams, Kristen; Yeoh, Yun Kit; Zammit, Carla M; Young, Andrew

    2016-01-01

    Microbial inhabitants of soils are important to ecosystem and planetary functions, yet there are large gaps in our knowledge of their diversity and ecology. The 'Biomes of Australian Soil Environments' (BASE) project has generated a database of microbial diversity with associated metadata across extensive environmental gradients at continental scale. As the characterisation of microbes rapidly expands, the BASE database provides an evolving platform for interrogating and integrating microbial diversity and function. BASE currently provides amplicon sequences and associated contextual data for over 900 sites encompassing all Australian states and territories, a wide variety of bioregions, vegetation and land-use types. Amplicons target bacteria, archaea and general and fungal-specific eukaryotes. The growing database will soon include metagenomics data. Data are provided in both raw sequence (FASTQ) and analysed OTU table formats and are accessed via the project's data portal, which provides a user-friendly search tool to quickly identify samples of interest. Processed data can be visually interrogated and intersected with other Australian diversity and environmental data using tools developed by the 'Atlas of Living Australia'. Developed within an open data framework, the BASE project is the first Australian soil microbial diversity database. The database will grow and link to other global efforts to explore microbial, plant, animal, and marine biodiversity. Its design and open access nature ensures that BASE will evolve as a valuable tool for documenting an often overlooked component of biodiversity and the many microbe-driven processes that are essential to sustain soil function and ecosystem services.

  14. PERMANENCE OF WATER EFFECTIVENESS IN THE ROOT ZONE OF THE CAATINGA BIOME

    Directory of Open Access Journals (Sweden)

    CARLOS ALEXANDRE GOMES COSTA

    2016-01-01

    Full Text Available Soil is an important water compartment into a watershed scale, mainly due to its role in providing water to plants and to the influence of antecedent moisture on the runoff initiation. The aim of this research is to assess the permanence of water effectiveness in the soil under preserved-vegetation constraints in the Caatinga biome, in the semiarid northeastern Brazil. For this purpose, hourly soil moisture measurements were collected with TDR and analyzed between 2003 and 2010 for three soil-vegetation associations in the Aiuaba Experimental Basin. The results showed that in nine months per year soil moisture was below wilting point for two associations, whose soils are Chromic Luvisol and Haplic Lixisol (Abruptic. In the third association, where the shallow soil Lithic Leptosol prevails, water was found non-effective four months per year. A possible reason for the high water permanence in the shallowest soil is the percolation process, generating sub-surface flow, which barely occurs in the deeper soils. In situ observations indicates that the long period of soil moisture below the wilting point was not enough to avoid the blooming season of the Caatinga vegetation during the rainy periods. Indeed, after the beginning of each rainy season, there is a growth of dense green vegetation, regardless of the long period under water shortage.

  15. Diversity of herbaceous plants and bacterial communities regulates soil resistome across forest biomes.

    Science.gov (United States)

    Hu, Hang-Wei; Wang, Jun-Tao; Singh, Brajesh K; Liu, Yu-Rong; Chen, Yong-Liang; Zhang, Yu-Jing; He, Ji-Zheng

    2018-04-24

    Antibiotic resistance is ancient and prevalent in natural ecosystems and evolved long before the utilization of synthetic antibiotics started, but factors influencing the large-scale distribution patterns of natural antibiotic resistance genes (ARGs) remain largely unknown. Here, a large-scale investigation over 4000 km was performed to profile soil ARGs, plant communities and bacterial communities from 300 quadrats across five forest biomes with minimal human impact. We detected diverse and abundant ARGs in forests, including over 160 genes conferring resistance to eight major categories of antibiotics. The diversity of ARGs was strongly and positively correlated with the diversity of bacteria, herbaceous plants and mobile genetic elements (MGEs). The ARG composition was strongly correlated with the taxonomic structure of bacteria and herbs. Consistent with this strong correlation, structural equation modelling demonstrated that the positive effects of bacterial and herb communities on ARG patterns were maintained even when simultaneously accounting for multiple drivers (climate, spatial predictors and edaphic factors). These findings suggest a paradigm that the interactions between aboveground and belowground communities shape the large-scale distribution of soil resistomes, providing new knowledge for tackling the emerging environmental antibiotic resistance. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

  16. Microbial quality of soil from the Pampa biome in response to different grazing pressures

    Directory of Open Access Journals (Sweden)

    Rafael S. Vargas

    2015-06-01

    Full Text Available The aim of this study was to evaluate the impact of different grazing pressures on the activity and diversity of soil bacteria. We performed a long-term experiment in Eldorado do Sul, southern Brazil, that assessed three levels of grazing pressure: high pressure (HP, with 4% herbage allowance (HA, moderate pressure (MP, with 12% HA, and low pressure (LP, with 16% HA. Two reference areas were also assessed, one of never-grazed native vegetation (NG and another of regenerated vegetation after two years of grazing (RG. Soil samples were evaluated for microbial biomass and enzymatic (β-glucosidase, arylsulfatase and urease activities. The structure of the bacterial community and the population of diazotrophic bacteria were evaluated by RFLP of the 16S rRNA and nifH genes, respectively. The diversity of diazotrophic bacteria was assessed by partial sequencing of the 16S rDNA gene. The presence of grazing animals increased soil microbial biomass in MP and HP. The structures of the bacterial community and the populations of diazotrophic bacteria were altered by the different grazing managements, with a greater diversity of diazotrophic bacteria in the LP treatment. Based on the characteristics evaluated, the MP treatment was the most appropriate for animal production and conservation of the Pampa biome.

  17. Termite assemblages in five semideciduous Atlantic Forest fragments in the northern coastland limit of the biome

    Directory of Open Access Journals (Sweden)

    Heitor Bruno de Araújo Souza

    2012-03-01

    Full Text Available Termites are abundant organisms in tropical ecosystems and strongly influence the litter decomposition and soil formation. Despite their importance, few studies about their assemblage structures have been made in Brazilian Atlantic Forest fragments, especially in the area located north of the São Francisco River. This study aims to analyze the assemblage composition of five Atlantic Forest fragments located in the northern biome limit along the Brazilian coast. A standardized sampling protocol of termites was applied in each fragment. Thirty-three termite species belonging to twenty genera and three families were found in the forest fragments. The wood-feeder group was dominant both concerning to species richness and number of encounters in all areas. In sites northern to 7°S, there is an evident simplification of the termite assemblage composition regarding species richness and number of encounters by feeding group. This fact is apparently due to a higher sandy level in soils and to semideciduous character of the vegetation in the northern fragments. Thus, even on the north of São Francisco River, termite biodiversity is heterogeneously spread with highest density of species in the portion between 07°S and São Francisco River mouth (10°29'S.

  18. Ornamental Eudicotyledons from grasslands of Pampa biome in Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    Ana De Araújo Carrion

    2012-10-01

    Full Text Available The present study aims at investigating the group of Eudicotyledons native plants with ornamental potential of grasslands from the Pampa biome in the south of Brazil. The Pampa presents a high level of biodiversity; however, it requires studies related to the richness of vascular plants and its biological and ecological knowledge. The purpose of this work is to elaborate a preliminary inventory of this group of plants, analyzing the ornamental potential of each specie and indicating those that could be considered as being priorities for the purpose of sustainable use with this objective. Some grassland species were selected through the search for information in herbarium registers, national and international works about decorative plants, floristic surveys, besides the authors´ practical knowledge. Some parameters and values were associated, aiming at reducing the subjectivity of the choice. The survey resulted in a list of 177 species distributed in 36 families and 101 genera. Among these species, ten presented high ornamental potential. These data show that the richness of the grassland native ornamental flora is high, even though its use is poorly known. The use of these plants, if in a sustainable manner, can produce economic and ecological benefits.

  19. Soil respiration at mean annual temperature predicts annual total across vegetation types and biomes

    Directory of Open Access Journals (Sweden)

    M. Bahn

    2010-07-01

    Full Text Available Soil respiration (SR constitutes the largest flux of CO2 from terrestrial ecosystems to the atmosphere. However, there still exist considerable uncertainties as to its actual magnitude, as well as its spatial and interannual variability. Based on a reanalysis and synthesis of 80 site-years for 57 forests, plantations, savannas, shrublands and grasslands from boreal to tropical climates we present evidence that total annual SR is closely related to SR at mean annual soil temperature (SRMAT, irrespective of the type of ecosystem and biome. This is theoretically expected for non water-limited ecosystems within most of the globally occurring range of annual temperature variability and sensitivity (Q10. We further show that for seasonally dry sites where annual precipitation (P is lower than potential evapotranspiration (PET, annual SR can be predicted from wet season SRMAT corrected for a factor related to P/PET. Our finding indicates that it can be sufficient to measure SRMAT for obtaining a well constrained estimate of its annual total. This should substantially increase our capacity for assessing the spatial distribution of soil CO2 emissions across ecosystems, landscapes and regions, and thereby contribute to improving the spatial resolution of a major component of the global carbon cycle.

  20. Methane Production and Transport within the Marsh Biome of Biosphere 2

    Science.gov (United States)

    Molnar, Jennifer; Goodridge, Kelven

    1997-01-01

    In recent decades, the concentration of methane in the earth's atmosphere increased 1-2% annually. It's rate of increases, combined with methane's effectiveness as a greenhouse gas, has led to an intensive research effort to determine the sources and sinks of the gas in the environment. Biosphere 2 offers a unique opportunity to contribute to the effort because it lacks a major photochemical sink present in the Earth's atmosphere. Researchers can therefore concentrate on biological processes involved in methane cycles. Wetlands are a large source of atmospheric methane, due to anoxic conditions in the sediments and the abundance of organic materials. In order to determine if these conditions in Biosphere 2 also promote methane production, this study looked for the fluxes of methane and methods of transport of the gas from from the water and sediments to the atmosphere in the Marsh Biome. Fluxes of methane from the sediments and waters were measured using static chambers, peepers, and leaf bags. Fluxes and vertical profiles of methane in the sediments show that substantial amounts of methane are being produced in the marsh and are being transported into the Biosphere 2 environment.

  1. Beyond aridification: multiple explanations for the elevated diversification of cacti in the New World Succulent Biome.

    Science.gov (United States)

    Hernández-Hernández, Tania; Brown, Joseph W; Schlumpberger, Boris O; Eguiarte, Luis E; Magallón, Susana

    2014-06-01

    Succulent plants are widely distributed, reaching their highest diversity in arid and semi-arid regions. Their origin and diversification is thought to be associated with a global expansion of aridity. We test this hypothesis by investigating the tempo and pattern of Cactaceae diversification. Our results contribute to the understanding of the evolution of New World Succulent Biomes. We use the most taxonomically complete dataset currently available for Cactaceae. We estimate divergence times and utilize Bayesian and maximum likelihood methods that account for nonrandom taxonomic sampling, possible extinction scenarios and phylogenetic uncertainty to analyze diversification rates, and evolution of growth form and pollination syndrome. Cactaceae originated shortly after the Eocene-Oligocene global drop in CO2 , and radiation of its richest genera coincided with the expansion of aridity in North America during the late Miocene. A significant correlation between growth form and pollination syndrome was found, as well as a clear state dependence between diversification rate, and pollination and growth-form evolution. This study suggests a complex picture underlying the diversification of Cactaceae. It not only responded to the availability of new niches resulting from aridification, but also to the correlated evolution of novel growth forms and reproductive strategies. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  2. Effect of postharvest practices including degreening on citrus carpoplane microbial biomes.

    Science.gov (United States)

    Gomba, A; Chidamba, L; Korsten, L

    2017-04-01

    To investigate the effect of commercial citrus packhouse processing steps on the fruit surface microbiome of Clementines and Palmer navel oranges. Viable bacteria, yeast and fungi counts, and the pyrosequencing analysis of the 16S rRNA and ITS were used to evaluate the community structure and population dynamics of phylloepiphytic bacteria and fungi associated with commercial postharvest processing. Drenching significantly reduced microbial counts in all cases except for yeasts on navels, while the extent of degreening effects varied between the citrus varieties. Pyrosequencing analysis showed a total of 4409 bacteria and 5792 fungi nonchimeric unique sequences with an average of 1102 bacteria and 1448 fungi reads per sample. Dominant phyla on the citrus carpoplane were Proteobacteria (53·5%), Actinobacteria (19·9%), Bacteroidetes (5·6%) and Deinococcus-Thermus (5·4%) for bacteria and Ascomycota (80·5%) and Basidiomycota (9·8%) for fungi. Beginning with freshly harvested fruit fungal diversity declined significantly after drenching, but had little effect on bacteria and populations recovered during degreening treatments, including those for Penicillium sp. Packhouse processing greatly influences microbial communities on the citrus carpoplane. A broad orange biome was described with pyrosequencing and gave insight into the likely survival and persistence of pathogens, especially as they may affect the quality and safety of the packed product. A close examination of the microbiota of fruit and the impact of intervention strategies on the ecological balance may provide a more durable approach to reduce losses and spoilage. © 2017 The Society for Applied Microbiology.

  3. Antimicrobial potential of actinobacteria isolated from the rhizosphere of the Caatinga biome plant Caesalpinia pyramidalis Tul.

    Science.gov (United States)

    Silva-Lacerda, G R; Santana, R C F; Vicalvi-Costa, M C V; Solidônio, E G; Sena, K X F R; Lima, G M S; Araújo, J M

    2016-03-04

    Actinobacteria are known to produce various secondary metabolites having antibiotic effects. This study assessed the antimicrobial potential of actinobacteria isolated from the rhizosphere of Caesalpinia pyramidalis Tul. from the Caatinga biome. Sixty-eight actinobacteria isolates were evaluated for antimicrobial activity against different microorganisms by disk diffusion and submerged fermentation, using different culture media, followed by determination of minimum inhibitory concentration (MIC) and chemical prospecting of the crude extract. Of the isolates studied, 52.9% of those isolated at 37°C and 47.05% of those isolated at 45°C had activity against Bacillus subtilis, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Fusarium moniliforme, and Candida albicans. When compared with others actinobacteria, the isolate C1.129 stood out with better activity and was identified by 16S rDNA gene analysis as Streptomyces parvulus. The crude ethanol extract showed an MIC of 0.97 μg/mL for MRSA and B. subtilis, while the ethyl acetate extract showed MIC of 3.9 μg/mL for S. aureus and MRSA, showing the greatest potential among the metabolites produced. Chemical prospecting revealed the presence of mono/sesquiterpenes, proanthocyanidin, triterpenes, and steroids in both crude extracts. This study evaluates S. parvulus activity against multi-resistant microorganisms such as MRSA. Thus, it proves that low-fertility soil, as is found in the Caatinga, may contain important microorganisms for the development of new antimicrobial drugs.

  4. Do language fluency and other socioeconomic factors influence the use of PubMed and MedlinePlus?

    Science.gov (United States)

    Sheets, L; Gavino, A; Callaghan, F; Fontelo, P

    2013-01-01

    Increased usage of MedlinePlus by Spanish-speakers was observed after introduction of MedlinePlus in Spanish. This probably reflects increased usage of MEDLINE and PubMed by those with greater fluency in the language in which it is presented; but this has never been demonstrated in English speakers. Evidence that lack of English fluency deters international healthcare personnel from using PubMed could support the use of multi-language search tools like Babel-MeSH. This study aims to measure the effects of language fluency and other socioeconomic factors on PubMed MEDLINE and MedlinePlus access by international users. We retrospectively reviewed server pageviews of PubMed and MedlinePlus from various periods of time, and analyzed them against country statistics on language fluency, GDP, literacy rate, Internet usage, medical schools, and physicians per capita, to determine whether they were associated. We found fluency in English to be positively associated with pageviews of PubMed and MedlinePlus in countries with high literacy rates. Spanish was generally found to be positively associated with pageviews of MedlinePlus en Español. The other parameters also showed varying degrees of association with pageviews. After adjusting for the other factors investigated in this study, language fluency was a consistently significant predictor of the use of PubMed, MedlinePlus English and MedlinePlus en Español. This study may support the need for multi-language search tools and may increase access of health information resources from non-English speaking countries.

  5. Vegetation of the Hantam-Tanqua-Roggeveld subregion, South Africa Part 2: Succulent Karoo Biome related vegetation

    Directory of Open Access Journals (Sweden)

    Helga van der Merwe

    2009-03-01

    Full Text Available The Hantam-Tanqua-Roggeveld subregion lies within the Succulent Karoo Hotspot that stretches along the western side of the Republic of South Africa and Namibia. This project, carried out to document the botanical diversity in the Hantam-Tanqua-Roggeveld subregion, was part of a project identified as a priority during the SKEP (Succulent Karoo Ecosystem Programme initiative in this Hotspot. Botanical surveys were conducted in an area covering over three million hectares. Satellite images of the area and topocadastral, land type and geology maps were used to stratify the area into relatively homogeneous units. An analysis of the floristic data of 390 sample plots identified two major floristic units, i.e. the Fynbos Biome related vegetation and the Succulent Karoo Biome related vegetation. A description of the vegetation related to the Succulent Karoo Biome is presented in this article. Seven associations, 16 subassociations and several mosaic vegetation units, consisting of more than one vegetation unit, were identified and mapped. Various threats to the vegetation in the region were identified during the survey and are briefly discussed.

  6. Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa.

    Science.gov (United States)

    Corbelli, Julian Martin; Zurita, Gustavo Andres; Filloy, Julieta; Galvis, Juan Pablo; Vespa, Natalia Isabel; Bellocq, Isabel

    2015-01-01

    The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD), functional (FBD) and phylogenetic (PBD) facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools) and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants) from two contrasting biomes (subtropical forest and grassland) and land uses (tree plantations and cropfields) in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland), and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation.

  7. Variation in decomposition rates in the fynbos biome, South Africa: the role of plant species and plant stoichiometry.

    Science.gov (United States)

    Bengtsson, Jan; Janion, Charlene; Chown, Steven L; Leinaas, Hans Petter

    2011-01-01

    Previous studies in the fynbos biome of the Western Cape, South Africa, have suggested that biological decomposition rates in the fynbos vegetation type, on poor soils, may be so low that fire is the main factor contributing to litter breakdown and nutrient release. However, the fynbos biome also comprises vegetation types on more fertile soils, such as the renosterveld. The latter is defined by the shrub Elytropappus rhinocerotis, while the shrub Galenia africana may become dominant in overgrazed areas. We examined decomposition of litter of these two species and the geophyte Watsonia borbonica in patches of renosterveld in an agricultural landscape. In particular, we sought to understand how plant species identity affects litter decomposition rates, especially through variation in litter stoichiometry. Decomposition (organic matter mass loss) varied greatly among the species, and was related to litter N and P content. G. africana, with highest nutrient content, lost 65% of its original mass after 180 days, while E. rhinocerotis had lost ca. 30%, and the very nutrient poor W. borbonica biome. Thus, biological decomposition has likely been underestimated and, along with small-scale variation in ecosystem processes, would repay further study.

  8. Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa

    Science.gov (United States)

    Corbelli, Julian Martin; Zurita, Gustavo Andres; Filloy, Julieta; Galvis, Juan Pablo; Vespa, Natalia Isabel; Bellocq, Isabel

    2015-01-01

    The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD), functional (FBD) and phylogenetic (PBD) facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools) and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants) from two contrasting biomes (subtropical forest and grassland) and land uses (tree plantations and cropfields) in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland), and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation. PMID:25978319

  9. Integrating Taxonomic, Functional and Phylogenetic Beta Diversities: Interactive Effects with the Biome and Land Use across Taxa.

    Directory of Open Access Journals (Sweden)

    Julian Martin Corbelli

    Full Text Available The spatial distribution of species, functional traits and phylogenetic relationships at both the regional and local scales provide complementary approaches to study patterns of biodiversity and help to untangle the mechanisms driving community assembly. Few studies have simultaneously considered the taxonomic (TBD, functional (FBD and phylogenetic (PBD facets of beta diversity. Here we analyze the associations between TBD, FBD, and PBD with the biome (representing different regional species pools and land use, and investigate whether TBD, FBD and PBD were correlated. In the study design we considered two widely used indicator taxa (birds and ants from two contrasting biomes (subtropical forest and grassland and land uses (tree plantations and cropfields in the southern Neotropics. Non-metric multidimensional scaling showed that taxonomic, functional and phylogenetic distances were associated to biome and land use; study sites grouped into four groups on the bi-dimensional space (cropfields in forest and grassland, and tree plantations in forest and grassland, and that was consistent across beta diversity facets and taxa. Mantel and PERMANOVA tests showed that TBD, FBD and PBD were positively correlated for both bird and ant assemblages; in general, partial correlations were also significant. Some of the functional traits considered here were conserved along phylogeny. Our results will contribute to the development of sound land use planning and beta diversity conservation.

  10. Modeling the Ecosystem Services Provided by Trees in Urban Ecosystems: Using Biome-BGC to Improve i-Tree Eco

    Science.gov (United States)

    Brown, Molly E.; McGroddy, Megan; Spence, Caitlin; Flake, Leah; Sarfraz, Amna; Nowak, David J.; Milesi, Cristina

    2012-01-01

    As the world becomes increasingly urban, the need to quantify the effect of trees in urban environments on energy usage, air pollution, local climate and nutrient run-off has increased. By identifying, quantifying and valuing the ecological activity that provides services in urban areas, stronger policies and improved quality of life for urban residents can be obtained. Here we focus on two radically different models that can be used to characterize urban forests. The i-Tree Eco model (formerly UFORE model) quantifies ecosystem services (e.g., air pollution removal, carbon storage) and values derived from urban trees based on field measurements of trees and local ancillary data sets. Biome-BGC (Biome BioGeoChemistry) is used to simulate the fluxes and storage of carbon, water, and nitrogen in natural environments. This paper compares i-Tree Eco's methods to those of Biome-BGC, which estimates the fluxes and storage of energy, carbon, water and nitrogen for vegetation and soil components of the ecosystem. We describe the two models and their differences in the way they calculate similar properties, with a focus on carbon and nitrogen. Finally, we discuss the implications of further integration of these two communities for land managers such as those in Maryland.

  11. Modeling distribution of Schinus molle L. in the Brazilian Pampa: insights on vegetation dynamics and conservation of the biome

    Directory of Open Access Journals (Sweden)

    R.P.M. Lemos

    2014-12-01

    Full Text Available Natural establishment of forests in the Brazilian Pampa biome should occur due to soil, hydrology and climate conditions, although no significant forest expansion over grassland has been noticed, precluded mainly by human interference and lack of environmental management. In this study, we used niche-modeling distribution of the tree species Schinus molle L. based on climatic variables to access the vegetation dynamics of the Brazilian Pampa and to develop strategies that assure the conservation of this biome, concerning both grassland and forest formations. Here we show that a large area of the Brazilian Pampa is suitable for expansion of S. molle populations, supporting the forest expansion over grassland as a natural process in this biome. We propose that the current absence of tree species expansion over the grassland in these areas is a result of the resilience of the grassland and of human interferences through expansion of agriculture, ranching and forestry with exotic species. Therefore, conservationist actions should focus on establishing preservation unities that include forest populations and grassland, while environmental management should be applied just in farming areas with historical human interference. Such actions will respect the ecological dynamics of the Pampa and value the forest formations in this grassland-dominated environment.

  12. Identification of novel mammalian hosts and Brazilian biome geographic distribution of Trypanosoma cruzi TcIII and TcIV.

    Science.gov (United States)

    Barros, Juliana Helena S; Xavier, Samanta Cristina C; Bilac, Daniele; Lima, Valdirene Santos; Dario, Maria Augusta; Jansen, Ana Maria

    2017-08-01

    Trypanosoma cruzi is a parasitic protozoan responsible for Chagas disease. Seven different Discrete Typing Units (DTUs) of T. cruzi are currently identified in nature: TcI-TcVI, and TcBat whose distribution patterns in nature, hosts/reservoirs and eco-epidemiological importance are still little known. Here, we present novel data on the geographic distribution and diversity of mammalian hosts and vectors of T. cruzi DTUs TcIII and TcIV. In this study, we analyzed 61 T. cruzi isolates obtained from 18 species of mammals (five orders) and two Hemiptera genera. Samples were collected from five Brazilian biomes (Pantanal, Caatinga, Cerrado, Atlantic Rainforest, and Amazon) previously characterized as Z3 or mixed infection (TcI-Z3) by mini-exon gene PCR. To identify TcIII and TcIV genotypes, we applied restriction fragment length polymorphism analysis to the PCR-amplified histone 3 gene. DTUs TcIII and TcIV were identified in single and mixed infections from wide dispersion throughout five Brazilian biomes studied, with TcIV being the most common. Pantanal was the biome that displayed the largest number of samples characterized as TcIII and TcIV in single and mixed infections, followed by Atlantic Rainforest and Amazon. Species from the Didelphimorphia order displayed the highest frequency of infection and were found in all five biomes. We report, for the first time, the infection of a species of the Artiodactyla order by DTU TcIII. In addition, we describe new host species: five mammals (marsupials and rodents) and two genera of Hemiptera. Our data indicate that DTUs TcIII and TcIV are more widespread and infect a larger number of mammalian species than previously thought. In addition, they are transmitted in restricted foci and cycles, but in different microhabitats and areas with distinct ecological profiles. Finally, we show that DTUs TcIII and TcIV do not present any specific association with biomes or host species. Copyright © 2017. Published by Elsevier B.V.

  13. Synergistic impacts of deforestation, climate change and fire on the future biomes distribution in Amazonia

    Science.gov (United States)

    Sampaio, G.; Cardoso, M. F.; Nobre, C. A.; Salazar, L. F.

    2013-05-01

    Several studies indicate future increase of environmental risks for the ecosystems in the Amazon region as a result of climate and land-use change, and their synergistic interactions. Modeling studies (e.g. Oyama and Nobre 2004, Salazar et al. 2007, Malhi et al. 2008) project rapid and irreversible replacement of forests by savannas with large-scale losses of biodiversity and livelihoods for people in the region. This process is referred to as the Amazon Dieback, where accelerated plant mortality due to environmental changes lead to forest collapse and savannas expansion after "tipping points" in climate and land surface changes are achieved. In this study we performed new analyses to quantify how deforestation, climate change and fire may combine to affect the distribution of major biomes in Amazonia. Changes in land use consider deforestation scenarios of 0%, 20%, 40%, and 50% (Sampaio et al., 2007), with and without fires (Cardoso et al., 2008), under the two greenhouse gases scenarios B1 and A2 and three "representative concentration pathways" (RCPs): 2.6, 4.5 and 8.5, for years 2015-2034 and 2040-2059 ("2025" and "2050" time-slices), from IPCC AR4 and CMIP5. The results show that the area affected in scenarios A2 and RCP 8.5 is larger than in the climate scenario B1 and RCP 2.6, and in both cases the effect is progressively higher in time. Most important changes occur in the East and South of the Amazon, with replacement of tropical forest by seasonal forest and savanna. The effect of fire in this region is important in all scenarios. The Northwest Amazon presents the smallest changes in the area of tropical forest, indicating that even for substantial land-use modifications and global climate change, the resulting atmospheric conditions would still support tropical forest in the region. In summary, we conclude that the synergistic combination of deforestation, climate change resulting from global warming, and the potential for higher fire occurrence may lead

  14. Adsorption-desorption reactions of selenium (VI) in tropical cultivated and uncultivated soils under Cerrado biome.

    Science.gov (United States)

    Lessa, J H L; Araujo, A M; Silva, G N T; Guilherme, L R G; Lopes, G

    2016-12-01

    Soil management may affect selenium (Se) adsorption capacity. This study investigated adsorption and desorption of Se (VI) in selected Brazilian soils from the Cerrado biome, an area of ever increasing importance for agriculture expansion in Brazil. Soil samples were collected from cultivated and uncultivated soils, comprising clayed and sandy soils. Following chemical and mineralogical characterization, soil samples were subjected to Se adsorption and desorption tests. Adsorption was evaluated after a 72-h reaction with increasing concentrations of Se (0-2000 μg L -1 ) added as Na 2 SeO 4 in a NaCl electrolyte solution (pH 5.5; ionic strength 15 mmol L -1 ). Desorption, as well as distribution coefficients (K d ) for selenate were also assessed. Soil management affected Se adsorption capacity, i.e., Se adsorbed amounts were higher for uncultivated soils, when compared to cultivated ones. Such results were also supported by data of K d and maximum adsorption capacity of Se. This fact was attributed mainly to the presence of greater amounts of competing anions, especially phosphate, in cultivated soils, due to fertilizer application. Phosphate may compete with selenate for adsorption sites, decreasing Se retention. For the same group of soils (cultivated and uncultivated), Se adsorption was greater in the clayed soils compared to sandy ones. Our results support the idea that adding Se (VI) to the soil is a good strategy to increase Se levels in food crops (agronomic biofortification), especially when crops are grown in soils that have been cultivated over the time due to their low Se adsorption capacity (high Se availability). Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Mosquito community composition in dynamic landscapes from the Atlantic Forest biome (Diptera, Culicidae

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    Mário Luís Pessôa Guedes

    2014-03-01

    Full Text Available Mosquito community composition in dynamic landscapes from the Atlantic Forest biome (Diptera, Culicidae. Considering that some species of Culicidae are vectors of pathogens, both the knowledge of the diversity of the mosquito fauna and how some environment factors influence in it, are important subjects. In order to address the composition of Culicidae species in a forest reserve in southern Atlantic Forest, we compared biotic and abiotic environmental determinants and how they were associated with the occurrence of species between sunset and sunrise. The level of conservation of the area was also considered. The investigation was carried out at Reserva Natural do Morro da Mina, in Antonina, state of Paraná, Brazil. We performed sixteen mosquito collections employing Shannon traps at three-hour intervals, from July 2008 to June 2009. The characterization of the area was determined using ecological indices of diversity, evenness, dominance and similarity. We compared the frequency of specimens with abiotic variables, i.e., temperature, relative humidity and pluviosity. Seven thousand four hundred ten mosquito females were captured. They belong to 48 species of 12 genera. The most abundant genera were Anopheles, Culex, Coquillettidia, Aedes and Runchomyia. Among the species, the most abundant was Anopheles cruzii, the primary vector of Plasmodium spp. in the Atlantic Forest. Results of the analyses showed that the abiotic variables we tested did not influence the occurrence of species, although certain values suggested that there was an optimum range for the occurrence of culicid species. It was possible to detect the presence of species of Culicidae with different epidemiologic profiles and habitat preference.

  16. Global pressures, specific responses: effects of nutrient enrichment in streams from different biomes

    International Nuclear Information System (INIS)

    Artigas, Joan; García-Berthou, Emili; Gómez, Nora; Romaní, Anna M; Sabater, Sergi; Bauer, Delia E; Cochero, Joaquín; Cortelezzi, Agustina; Rodrigues-Capítulo, Alberto; Castro, Maria I; Donato, John C; Colautti, Darío C; Elosegi, Arturo; Feijoó, Claudia; Giorgi, Adonis; Leggieri, Leonardo; Muñoz, Isabel

    2013-01-01

    We assessed the effects of nutrient enrichment on three stream ecosystems running through distinct biomes (Mediterranean, Pampean and Andean). We increased the concentrations of N and P in the stream water 1.6–4-fold following a before–after control–impact paired series (BACIPS) design in each stream, and evaluated changes in the biomass of bacteria, primary producers, invertebrates and fish in the enriched (E) versus control (C) reaches after nutrient addition through a predictive-BACIPS approach. The treatment produced variable biomass responses (2–77% of explained variance) among biological communities and streams. The greatest biomass response was observed for algae in the Andean stream (77% of the variance), although fish also showed important biomass responses (about 9–48%). The strongest biomass response to enrichment (77% in all biological compartments) was found in the Andean stream. The magnitude and seasonality of biomass responses to enrichment were highly site specific, often depending on the basal nutrient concentration and on windows of ecological opportunity (periods when environmental constraints other than nutrients do not limit biomass growth). The Pampean stream, with high basal nutrient concentrations, showed a weak response to enrichment (except for invertebrates), whereas the greater responses of Andean stream communities were presumably favored by wider windows of ecological opportunity in comparison to those from the Mediterranean stream. Despite variation among sites, enrichment globally stimulated the algal-based food webs (algae and invertebrate grazers) but not the detritus-based food webs (bacteria and invertebrate shredders). This study shows that nutrient enrichment tends to globally enhance the biomass of stream biological assemblages, but that its magnitude and extent within the food web are complex and are strongly determined by environmental factors and ecosystem structure. (letter)

  17. Implications of a lightning-rich tundra biome for permafrost carbon and vegetation dynamics

    Science.gov (United States)

    Chen, Y.; Veraverbeke, S.; Randerson, J. T.

    2017-12-01

    Lightning is a major ignition source of wildfires in circumpolar boreal forests but rarely occurs in arctic tundra. While theoretical and empirical work suggests that climate change will increase lightning strikes in temperate regions, much less is known about future changes in lightning across terrestrial ecosystems at high northern latitudes. Here we analyzed the spatial and temporal patterns of lightning flash rate (FR) from the satellite observations and surface detection networks. Regression models between the observed FR from the Optical Transient Detector on the MicroLab-1 satellite (later renamed OV-1) and meteorological parameters, including surface temperature (T), convective available potential energy (CAPE), and convective precipitation (CP) from ECMWF (European Centre for Medium-Range Weather Forecasts) ERA-interim reanalysis, were established and assessed. We found that FR had significant linear correlations with CAPE and CP, and a strong non-linear relationship with T. The statistical model based on T and CP can reproduce most of the spatial and temporal variability in FR in the circumpolar region. By using the regression model and meteorological predictions from 24 earth system models in the Coupled Model Intercomparison Project Phase 5 (CMIP5), we estimated the spatial distribution of FR by the end of the 21st century. Due to increases in surface temperature and convection, modeled FR shows substantial increase in northern biomes, including a 338% change in arctic tundra and a 185% change in regions with permafrost soil carbon reservoirs. These changes highlight a new mechanism by which permafrost carbon is vulnerable to the sustained impacts of climate warming. Increased fire in a warmer and lightning-rich future near the treeline has the potential to accelerate the northward migration of trees, which may further enhance warming and the abundance of lightning strikes.

  18. Regional Atmospheric CO2 Inversion Reveals Seasonal and Geographic Differences in Amazon Net Biome Exchange

    Science.gov (United States)

    Alden, Caroline B.; Miller, John B.; Gatti, Luciana V.; Gloor, Manuel M.; Guan, Kaiyu; Michalak, Anna M.; van der Laan-Luijkx, Ingrid; Touma, Danielle; Andrews, Arlyn; Basso, Luana G.; hide

    2016-01-01

    Understanding tropical rainforest carbon exchange and its response to heat and drought is critical for quantifying the effects of climate change on tropical ecosystems, including global climate carbon feedbacks. Of particular importance for the global carbon budget is net biome exchange of CO2 with the atmosphere (NBE), which represents nonfire carbon fluxes into and out of biomass and soils. Subannual and sub-Basin Amazon NBE estimates have relied heavily on process-based biosphere models, despite lack of model agreement with plot-scale observations. We present a new analysis of airborne measurements that reveals monthly, regional-scale (Approx.1-8 x 10(exp -6) km2) NBE variations. We develop a regional atmospheric CO2 inversion that provides the first analysis of geographic and temporal variability in Amazon biosphere-atmosphere carbon exchange and that is minimally influenced by biosphere model-based first guesses of seasonal and annual mean fluxes. We find little evidence for a clear seasonal cycle in Amazon NBE but do find NBE sensitivity to aberrations from long-term mean climate. In particular, we observe increased NBE (more carbon emitted to the atmosphere) associated with heat and drought in 2010, and correlations between wet season NBE and precipitation (negative correlation) and temperature (positive correlation). In the eastern Amazon, pulses of increased NBE persisted through 2011, suggesting legacy effects of 2010 heat and drought. We also identify regional differences in postdrought NBE that appear related to long-term water availability. We examine satellite proxies and find evidence for higher gross primary productivity (GPP) during a pulse of increased carbon uptake in 2011, and lower GPP during a period of increased NBE in the 2010 dry season drought, but links between GPP and NBE changes are not conclusive. These results provide novel evidence of NBE sensitivity to short-term temperature and moisture extremes in the Amazon, where monthly and sub

  19. Requisitos uniformes para preparar los manuscritos enviados a revistas biomédicas

    Directory of Open Access Journals (Sweden)

    1998-01-01

    Full Text Available En 1978, un reducido grupo de directores de revistas médicas generales que se publican en inglés se reunió de manera informal en Vancouver (Canadá a fin de fijar normas con respecto al formato que deberían adoptar los manuscritos enviados a esas publicaciones. Este fue el inicio de lo que con el tiempo llegó a conocerse como el Grupo de Vancouver. Sus requisitos para la preparación de manuscritos, que incluían el formato de las referencias bibliográficas creado por la Biblioteca Nacional de Medicina de los Estados Unidos, se publicaron por vez primera en 1979. Con el paso del tiempo el Grupo de Vancouver creció y se convirtió en el Comité Internacional de Directores de Revistas Médicas (CIDRM, que se reúne una vez al año y que gradualmente ha venido ampliando los temas que le conciernen. El Comité ha producido cinco ediciones de los requisitos uniformes para preparar los manuscritos enviados a revistas biomédicas. A lo largo de los años han surgido asuntos que van más allá de la preparación del manuscrito. Algunos de esos asuntos se han incorporado a los requisitos uniformes, mientras que otros se tratan en declaraciones por separado. Cada declaración se ha publicado en una revista científica.

  20. Net Biome Productivity of different land use at the sites of the Tharandt cluster

    Science.gov (United States)

    Grünwald, T.; Prescher, A.-K.; Bernhofer, Ch.

    2009-04-01

    Within the Tharandt cluster there are 5 flux monitoring sites including 3 CARBOEUROPE main sites. The CARBOEUROPE sites cover typical land use of the region (spruce [monitored since 1996], grassland [since 2003], cropland [since 2004]). For all sites estimates of the Net Biome Productivity (NBP) and its uncertainty have been derived using Net Ecosystem Productivity (NEP) based on the EC measurements and C exports and imports on an annual basis. The crop site is a small C sink (NEP of 30-110gCm-2a-1) only. The annual NEP values are dependent on the cultivated crop species (winter or summer crop). Including C export (harvest) and C import (manure spreading) lead to a considerable C source of 270-540gCm-2a-1. Organic fertilisation (C import) has a strong impact on NBP values expressed in a reduced annual net carbon source. Also, the largest interannual differences of NBP values are found at this site - mainly induced by the existence and the amount of a carbon import due to organic fertilisation. Management practices affect the NBP in a sensitive way at this crop site. Each crop shows a higher C export due to harvest than the annual NEP. To validate the calculated C equivalent using harvested grain biomass modelled NPP values are available. Uncertainty ranges of C export, C import and NBP as well as the grassland and spruce NBP (for comparison) are also stated. In general, land use and management strongly affect the annual NBP of non-forested ecosystems especially. So, this is the second main driver of the C budget besides the interannual variability in meteorological conditions and water availability with its influence on NEP, GPP and TER.

  1. Ecosystem-scale carbon monoxide exchange and partitioning across major biomes in Europe

    Science.gov (United States)

    Hammerle, Albin; Spielmann, Felix; Kitz, Florian; Ibrom, Andreas; Migliavacca, Mirco; Noe, Steffen; Kolle, Olaf; Moreno, Gerardo; Wohlfahrt, Georg

    2017-04-01

    With an average mole fraction of 100 ppb carbon monoxide (CO) plays a critical role in atmospheric chemistry and has an indirect global warming potential. While sources/sinks of CO on land at least partially cancel out each other and their magnitude is very likely lower compared to other sinks and sources, the magnitude of CO sources and sinks is highly uncertain. Thus it may be premature to neglect any direct contributions of land ecosystems to the CO budget. In addition, changes in global climate and resulting changes in global productivity may require re-evaluating older data and assumptions. One major reason for the large uncertainty is a general scarcity of empirical data. Here we present data on continuous eddy covariance measurements of CO-fluxes above different biomes in Europe in combination with soil-chamber flux measurements. Eddy covariance and soil-chamber measurements were conducted during the vegetation periods in 2015 and 2016 at a temperate grassland (AUT), a Mediterranean savanna (ESP), a temperate mixed deciduous (DEN) and a hemi-boreal forest (EST). While a clear diel pattern in ecosystem-scale CO-fluxes could be observed at the two grassland sites, with comparatively high emission rates at daytime conditions and fluxes around zero at night, no such pattern could be found for the two forest sites. Soil-chamber measurements mimicked the ecosystem-scale fluxes with CO-emissions during the day at the grassland ecosystems and slightly negative fluxes at night. Applying different treatments the influence of radiation and the availability of litter on these fluxes could be shown. Furthermore, a two-month rainout experiment revealed hardly any differences in CO soil fluxes between rainout- and control-plots at the grassland site (AUT), unless extremely dry conditions were reached.

  2. Assessing MODIS GPP in Non-Forested Biomes in Water Limited Areas Using EC Tower Data

    Directory of Open Access Journals (Sweden)

    Flor Álvarez-Taboada

    2015-03-01

    Full Text Available Although shrublands, savannas and grasslands account for 37% of the world’s terrestrial area, not many studies have analysed the role of these ecosystems in the global carbon cycle at a regional scale. The MODIS Gross Primary Production (GPP product is used here to help bridge this gap. In this study, the agreement between the MODIS GPP product (GPPm and the GPP Eddy Covariance tower data (GPPec was tested for six different sites in temperate and dry climatic regions (three grasslands, two shrublands and one evergreen forest. Results of this study show that for the non-forest sites in water-limited areas, GPPm is well correlated with GPPec at annual scales (r2 = 0.77, n = 12; SEE = 149.26 g C∙m−2∙year−1, although it tends to overestimate GPP and it is less accurate in the sites with permanent water restrictions. The use of biome-specific models based on precipitation measurements at a finer spatial resolution than the Data Assimilation Office (DAO values can increase the accuracy of these estimations. The seasonal dynamics and the beginning and end of the growing season were well captured by GPPm for the sites where (i the productivity was low throughout the year or (ii the changes in the flux trend were abrupt, usually due to the restrictions in water availability. The agreement between GPPec and GPPm in non-forested sites was lower on a weekly basis than at an annual scale (0.44 ≤ r2 ≤ 0.49, but these results were improved by including meteorological data at a finer spatial scale, and soil water content and temperature measurements in the model developed to predict GPPec (0.52 ≤ r2 ≤ 0.65.

  3. Quantitative comparison of the in situ microbial communities in different biomes

    Energy Technology Data Exchange (ETDEWEB)

    White, D.C. [Tennessee Univ., Knoxville, TN (United States)]|[Oak Ridge National Lab., TN (United States); Ringelberg, D.B.; Palmer, R.J. [Tennessee Univ., Knoxville, TN (United States). Center for Environmental Biotechnology

    1995-12-31

    A system to define microbial communities in different biomes requires the application of non-traditional methodology. Classical microbiological methods have severe limitations for the analysis of environmental samples. Pure-culture isolation, biochemical testing, and/or enumeration by direct microscopic counting are not well suited for the estimation of total biomass or the assessment of community composition within environmental samples. Such methods provide little insight into the in situ phenotypic activity of the extant microbiota since these techniques are dependent on microbial growth and thus select against many environmental microorganisms which are non- culturable under a wide range of conditions. It has been repeatedly documented in the literature that viable counts or direct counts of bacteria attached to sediment grains are difficult to quantitative and may grossly underestimate the extent of the existing community. The traditional tests provide little indication of the in situ nutritional status or for evidence of toxicity within the microbial community. A more recent development (MIDI Microbial Identification System), measure free and ester-linked fatty acids from isolated microorganisms. Bacterial isolates are identified by comparing their fatty acid profiles to the MIKI database which contains over 8000 entries. The application of the MIKI system to the analysis of environmental samples however, has significant drawbacks. The MIDI system was developed to identify clinical microorganisms and requires their isolation and culture on trypticase soy agar at 27{degrees}C. Since many isolates are unable to grow at these restrictive growth conditions, the system does not lend itself to identification of some environmental organisms. A more applicable methodology for environmental microbial analysis is based on the liquid extrication and separation of microbial lipids from environmental samples, followed by quantitative analysis using gas chromatography/

  4. Drivers of leaf carbon exchange capacity across biomes at the continental scale.

    Science.gov (United States)

    Smith, Nicholas G; Dukes, Jeffrey S

    2018-04-29

    Realistic representations of plant carbon exchange processes are necessary to reliably simulate biosphere-atmosphere feedbacks. These processes are known to vary over time and space, though the drivers of the underlying rates are still widely debated in the literature. Here, we measured leaf carbon exchange in >500 individuals of 98 species from the neotropics to high boreal biomes to determine the drivers of photosynthetic and dark respiration capacity. Covariate abiotic (long- and short-term climate) and biotic (plant type, plant size, ontogeny, water status) data were used to explore significant drivers of temperature-standardized leaf carbon exchange rates. Using model selection, we found the previous week's temperature and soil moisture at the time of measurement to be a better predictor of photosynthetic capacity than long-term climate, with the combination of high recent temperatures and low soil moisture tending to decrease photosynthetic capacity. Non-trees (annual and perennials) tended to have greater photosynthetic capacity than trees, and, within trees, adults tended to have greater photosynthetic capacity than juveniles, possibly as a result of differences in light availability. Dark respiration capacity was less responsive to the assessed drivers than photosynthetic capacity, with rates best predicted by multi-year average site temperature alone. Our results suggest that, across large spatial scales, photosynthetic capacity quickly adjusts to changing environmental conditions, namely light, temperature, and soil moisture. Respiratory capacity is more conservative and most responsive to longer-term conditions. Our results provide a framework for incorporating these processes into large-scale models and a dataset to benchmark such models. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  5. FLUXAPYROXAD IN THE ASIAN SOYBEAN RUST CONTROL IN THE CERRADO BIOME

    Directory of Open Access Journals (Sweden)

    RAFAEL MENEZES SILVA DE FREITAS

    2016-01-01

    Full Text Available The etiologic agent of the Asian soybean rust is the Phakopsora pachyrhizi, which causes a reduction in the photosynthetic leaf area and, consequently, in the crop yield. Chemical control is one of the main measures for its management. The objective of this work was to evaluate the efficacy and selectivity of the fluxapyroxad fungicide on controlling the Asian soybean rust, under the edaphoclimatic conditions of the Cerrado biome. The experiment was conducted in an area under no-tillage system, in the Agricultural Research Center, Rio Verde, Goias, Brazil, during the 2012/2013 crop season, using the cultivar NA7337. A randomized block experimental design was used, with twelve treatments and four replications. The treatments consisted of applications of fluxapyroxad (FX, pyraclostrobin (PT, epoxiconazole (EX and metconazole (MZ. The average severity of the disease in the plants reached 37% in the Control. All treatments with fungicides differed from the Control. Treatments 9, 10, 11 and 12 provided the greatest rates of soybean rust control. The treatments 10, 11 and 12 had the highest thousand grain weights, and the yields of the treatments 2, 3 and 11, despite higher than the Control, were lower than the treatments 4, 5, 6, 7, 8, 9, 10 and 12, which had statistically equal yields. The increasing in yield, compared to the Control, ranged from 10.05% (pyraclostrobin, epoxiconazole + pyraclostrobin + mineral oil to 30.55% (pyraclostrobin, pyraclostrobin + fluxapyroxad + mineral oil and pyraclostrobin + metconazole + mineral oil. The highest rates of soybean rust control were presented by fungicides containing fluxapyroxad.

  6. Examining the role of dissolved organic nitrogen in stream ecosystems across biomes and Critical Zone gradients

    Science.gov (United States)

    Wymore, A.; Rodriguez-Cardona, B.; Coble, A. A.; Potter, J.; Lopez Lloreda, C.; Perez Rivera, K.; De Jesus Roman, A.; Bernal, S.; Martí Roca, E.; Kram, P.; Hruska, J.; Prokishkin, A. S.; McDowell, W. H.

    2016-12-01

    Watershed nitrogen exports are often dominated by dissolved organic nitrogen (DON); yet, little is known about the role ambient DON plays in ecosystems. As an organic nutrient, DON may serve as either an energy source or as a nutrient source. One hypothesized control on DON is nitrate (NO3-) availability. Here we examine the interaction of NO3- and DON in streams across temperate forests, tropical rainforests, and Mediterranean and taiga biomes. Experimental streams also drain contrasting Critical Zones which provide gradients of vegetation, soil type and lithology (e.g. volcaniclastic, granitic, ultramafic, Siberian Traps Flood Basalt) in which to explore how the architecture of the Critical Zone affects microbial biogeochemical reactions. Streams ranged in background dissolved organic carbon (DOC) concentration (1-50 mg C/L) and DOC: NO3- ratios (10-2000). We performed a series of ecosystem-scale NO3- additions in multiple streams within each environment and measured the change in DON concentration. Results demonstrate that there is considerable temporal and spatial variation across systems with DON both increasing and decreasing in response to NO3- addition. Ecologically this suggests that DON can serve as both a nutrient source and an energy source to aquatic microbial communities. In contrast, DOC concentrations rarely changed in response to NO3- additions suggesting that the N-rich fraction of the ambient dissolved organic matter pool is more bioreactive than the C-rich fraction. Contrasting responses of the DON and DOC pools indicate different mechanisms controlling their respective cycling. It is likely that DON plays a larger role in ecosystems than previously recognized.

  7. Web-Scale Discovery Services Retrieve Relevant Results in Health Sciences Topics Including MEDLINE Content

    Directory of Open Access Journals (Sweden)

    Elizabeth Margaret Stovold

    2017-06-01

    Full Text Available A Review of: Hanneke, R., & O’Brien, K. K. (2016. Comparison of three web-scale discovery services for health sciences research. Journal of the Medical Library Association, 104(2, 109-117. http://dx.doi.org/10.3163/1536-5050.104.2.004 Abstract Objective – To compare the results of health sciences search queries in three web-scale discovery (WSD services for relevance, duplicate detection, and retrieval of MEDLINE content. Design – Comparative evaluation and bibliometric study. Setting – Six university libraries in the United States of America. Subjects – Three commercial WSD services: Primo, Summon, and EBSCO Discovery Service (EDS. Methods – The authors collected data at six universities, including their own. They tested each of the three WSDs at two data collection sites. However, since one of the sites was using a legacy version of Summon that was due to be upgraded, data collected for Summon at this site were considered obsolete and excluded from the analysis. The authors generated three questions for each of six major health disciplines, then designed simple keyword searches to mimic typical student search behaviours. They captured the first 20 results from each query run at each test site, to represent the first “page” of results, giving a total of 2,086 total search results. These were independently assessed for relevance to the topic. Authors resolved disagreements by discussion, and calculated a kappa inter-observer score. They retained duplicate records within the results so that the duplicate detection by the WSDs could be compared. They assessed MEDLINE coverage by the WSDs in several ways. Using precise strategies to generate a relevant set of articles, they conducted one search from each of the six disciplines in PubMed so that they could compare retrieval of MEDLINE content. These results were cross-checked against the first 20 results from the corresponding query in the WSDs. To aid investigation of overall

  8. Welcome from Library Director Donald A.B. Lindberg, M.D. | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... turn Javascript on. Welcome to the NIH MedlinePlus Magazine. Past Issues / Spring 2013 Table of Contents Donald ... about their efforts to cure disease. Lastly, the magazine's lively graphics, fun quizzes and practical tips have ...

  9. Milestones in Medical Research, The Human Genome and ClinicalTrials.gov | NIH MedlinePlus the Magazine

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    ... the information in this issue of NIH MedlinePlus magazine helps you and your loved ones stay healthier! ... From You! We want your feedback on the magazine, ideas for future issues, as well as questions ...

  10. National Library of Medicine Celebrates 30 Years of Progress and Charts the Future | NIH MedlinePlus the Magazine

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    ... described the genesis of the National Center for Biotechnology Information (NCBI); the Visible Human Project (a digital ... expand the publication and distribution of NIH MedlinePlus magazine, thousands and thousands more people will gain valuable, ...

  11. A Review of Published Articles in the Field of Biomedical Nanotechnology in Medline Database during 2000-2010

    OpenAIRE

    Peyman Sheikhzade

    2015-01-01

    Background and objectives : Nanotechnology is a new technology which is increasingly used over the past decade. Due to its great significance, governments are tending to invest greatly on the research and development on nanotechnology in various sectors and aspects. The purpose of this study was to determine the status of biomedical nanotechnology publications over the past ten years (2010-2000) in Medline/ PubMed. Material and Methods : This was a descriptive study. The Medline database wa...

  12. Towards reconstructing herbaceous biome dynamics and associated precipitation in Africa: insights from the classification of grass morphological traits

    Science.gov (United States)

    Pasturel, Marine; Alexandre, Anne; Novello, Alice; Moctar Dieye, Amadou; Wele, Abdoulaye; Paradis, Laure; Hely, Christelle

    2014-05-01

    Inter-tropical herbaceous ecosystems occupy a 1/5th of terrestrial surface, a half of the African continent, and are expected to extend in the next decades. Dynamic of these ecosystems is simulated with poor accuracy by Dynamic Global Vegetation Models (DGVMs). One of the bias results from the fact that the diversity of the grass layer dominating these herbaceous ecosystems is poorly taken into account. Mean annual precipitation and the length of the dry season are the main constrains of the dynamics of these ecosystems. Conversely, changes in vegetation affect the water cycle. Inaccuracy in herbaceous ecosystem simulation thus impacts simulations of the water cycle (including precipitation) and vice versa. In order to increase our knowledge of the relationships between grass morphological traits, taxonomy, biomes and climatic niches in Western and South Africa, a 3-step methodology was followed: i) values of culm height, leaf length and width of dominant grass species from Senegal were gathered from flora and clustered using the Partition Around Medoids (PAM) method; ii) trait group ability to sign climatic domains and biomes was assessed using Kruskal-Wallis tests; iii) genericity and robustness of the trait groups were evaluated through their application to Chadian and South African botanical datasets. Results show that 8 grass trait groups are present either in Senegal, Chad or South Africa. These 8 trait groups are distributed along mean annual precipitation and dry season length gradients. The combination of three of them allow to discriminate mean annual precipitation domains (1000 mm) and herbaceous biomes (steppes, savannas, South African grasslands and Nama-Karoo). With these results in hand, grass Plant Functional Types (PFTs) of the DGMV LPJ-GUESS will be re-parameterized and particular attention will be given to the herbaceous biomass assigned to each grass trait group. Simultaneously, relationships between grass trait groups and phytolith vegetation

  13. The Intestinal Eukaryotic and Bacterial Biome of Spotted Hyenas: The Impact of Social Status and Age on Diversity and Composition.

    Science.gov (United States)

    Heitlinger, Emanuel; Ferreira, Susana C M; Thierer, Dagmar; Hofer, Heribert; East, Marion L

    2017-01-01

    In mammals, two factors likely to affect the diversity and composition of intestinal bacteria (bacterial microbiome) and eukaryotes (eukaryome) are social status and age. In species in which social status determines access to resources, socially dominant animals maintain better immune processes and health status than subordinates. As high species diversity is an index of ecosystem health, the intestinal biome of healthier, socially dominant animals should be more diverse than those of subordinates. Gradual colonization of the juvenile intestine after birth predicts lower intestinal biome diversity in juveniles than adults. We tested these predictions on the effect of: (1) age (juvenile/adult) and (2) social status (low/high) on bacterial microbiome and eukaryome diversity and composition in the spotted hyena ( Crocuta crocuta ), a highly social, female-dominated carnivore in which social status determines access to resources. We comprehensively screened feces from 35 individually known adult females and 7 juveniles in the Serengeti ecosystem for bacteria and eukaryotes, using a set of 48 different amplicons (4 for bacterial 16S, 44 for eukaryote 18S) in a multi-amplicon sequencing approach. We compared sequence abundances to classical coprological egg or oocyst counts. For all parasite taxa detected in more than six samples, the number of sequence reads significantly predicted the number of eggs or oocysts counted, underscoring the value of an amplicon sequencing approach for quantitative measurements of parasite load. In line with our predictions, our results revealed a significantly less diverse microbiome in juveniles than adults and a significantly higher diversity of eukaryotes in high-ranking than low-ranking animals. We propose that free-ranging wildlife can provide an intriguing model system to assess the adaptive value of intestinal biome diversity for both bacteria and eukaryotes.

  14. From the lab - Eyes May be ‘Windows to the Brain’ in Stroke Patients | NIH MedlinePlus the Magazine

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    Skip to main content NIH MedlinePlus the Magazine NIH MedlinePlus Salud Download the Current Issue PDF [3.1 mb] Trusted Health Information from the National Institutes of Health Home Current Issue ...

  15. Aplicaciones del SiC biomórfico como reforzante estructural en hormigones refractarios

    Directory of Open Access Journals (Sweden)

    Sepúlveda, R.

    2005-10-01

    Full Text Available This work is devoted to the study of the time and temperature dependence of the static grain growth in YTZP 4 mol %, with an average grain size within the submicrometric range (> 0.1 μm. Also, the mechanical response in the temperature interval between 1200 ºC and 1500 ºC is analysed. The grain growth is controlled by the yttria segregation at the grain boundaries, which plays a key role in the cationic diffusion processes. Microstructural characterization of both as-received and deformed samples allows to conclude that plastic deformation is due to grain boundary sliding (GBS, with stress exponents increasing with the flow stress, but in all cases they are lower than n = 2.

    Una posible aplicación del SiC biomórfico (bioSiC son los reforzante estructural en hormigones refractarios. En este caso se han fabricado piezas de bioSiC con forma de cilindros alargados, 3-4 mm de diámetro y 30-35 mm de longitud, mediante infiltración reactiva de Si líquido en piezas de carbón obtenidas por pirolización de madera de haya de calidad comercial. Hemos estudiado las características microestructurales y las propiedades mecánicas de los reforzantes, como paso previo al estudio de la aplicación mencionada, de la que se ofrece un avance en este trabajo. Para caracterizar la calidad del material y del proceso de fabricación, la microestructura de las piezas se ha estudiado mediante microscopía electrónica de barrido. Los reforzantes de bioSiC fueron ensayados a compresión uniaxial y flexión en cuatro puntos a temperatura ambiente y a alta temperatura (1250-1400ºC para la determinación de sus propiedades mecánicas, y se realizaron estudios fractográficos en el segundo tipo de ensayos. Subsecuentemente, se prepararon ladrillos refractarios con un 3% en peso de reforzantes de bioSiC, que fueron curados a diferentes temperaturas (máx. 1600ºC. Estos ladrillos se han ensayado en compresión y flexión en tres puntos, a temperatura ambiente

  16. A cross-biome synthesis of soil respiration and its determinants under simulated precipitation changes.

    Science.gov (United States)

    Liu, Lingli; Wang, Xin; Lajeunesse, Marc J; Miao, Guofang; Piao, Shilong; Wan, Shiqiang; Wu, Yuxin; Wang, Zhenhua; Yang, Sen; Li, Ping; Deng, Meifeng

    2016-04-01

    Soil respiration (Rs) is the second-largest terrestrial carbon (C) flux. Although Rs has been extensively studied across a broad range of biomes, there is surprisingly little consensus on how the spatiotemporal patterns of Rs will be altered in a warming climate with changing precipitation regimes. Here, we present a global synthesis Rs data from studies that have manipulated precipitation in the field by collating studies from 113 increased precipitation treatments, 91 decreased precipitation treatments, and 14 prolonged drought treatments. Our meta-analysis indicated that when the increased precipitation treatments were normalized to 28% above the ambient level, the soil moisture, Rs, and the temperature sensitivity (Q10) values increased by an average of 17%, 16%, and 6%, respectively, and the soil temperature decreased by -1.3%. The greatest increases in Rs and Q10 were observed in arid areas, and the stimulation rates decreased with increases in climate humidity. When the decreased precipitation treatments were normalized to 28% below the ambient level, the soil moisture and Rs values decreased by an average of -14% and -17%, respectively, and the soil temperature and Q10 values were not altered. The reductions in soil moisture tended to be greater in more humid areas. Prolonged drought without alterations in the amount of precipitation reduced the soil moisture and Rs by -12% and -6%, respectively, but did not alter Q10. Overall, our synthesis suggests that soil moisture and Rs tend to be more sensitive to increased precipitation in more arid areas and more responsive to decreased precipitation in more humid areas. The responses of Rs and Q10 were predominantly driven by precipitation-induced changes in the soil moisture, whereas changes in the soil temperature had limited impacts. Finally, our synthesis of prolonged drought experiments also emphasizes the importance of the timing and frequency of precipitation events on ecosystem C cycles. Given these

  17. Gully erosion in the Caatinga biome, Brazil: measurement and stochastic modelling

    Science.gov (United States)

    Lima Alencar, Pedro Henrique; de Araújo, José Carlos; Nonato Távora Costa, Raimundo

    2017-04-01

    In contrast with inter-rill erosion, which takes a long time to modify the terrain form, gully erosion can fast and severely change the landscape. In the Brazilian semiarid region, a one-million km2 area that coincides with the Caatinga biome, inter-rill erosion prevails due to the silty shallow soils. However, gully erosion does occur in the Caatinga, with temporal increasing severity. This source of sediment impacts the existing dense network of small dams, generating significant deleterious effects, such as water availability reduction in a drought-prone region. This study focuses on the Madalena basin (124 km2, state of Ceará, Brazil), a land-reform settlement with 20 inhabitants per km2, whose main economic activities are agriculture (especially Zea mays), livestock and fishing. In the catchment area, where there are 12 dams (with storage capacity ranging from 6.104 to 2.107 m3), gully erosion has become an issue due to its increasing occurrence. Eight gully-erosion sites have been identified in the basin, but most of them have not yet reached great dimensions (depth and/or width), nor interacted with groundwater, being therefore classified as ephemeral gullies. We selected the three most relevant sites and measured the topography of the eroded channels, as well as the neighboring terrain relief, using accurate total stations and unmanned aerial vehicle. The data was processed with the help of software, such as DataGeosis (Office 7.5) and Surfer (11.0), providing information on gully erosion in terms of (μ ± σ): projection area (317±165 m2), eroded mass (61±36 Mg) and volume (42±25 m3), length (38±6 m), maximum depth (0.58±0.13 m) and maximum width (6.00±2.35 m). The measured data are then compared with those provided by the Foster and Lane model (1986). The model generated results with considerable scatter. This is possibly due to uncertainties in the field parameters, which are neglected in the deterministic approach of most physically-based models

  18. Holocene evolution of lakes in the forest-tundra biome of northern Manitoba, Canada

    Science.gov (United States)

    Hobbs, William O.; Edlund, Mark B.; Umbanhowar, Charles E.; Camill, Philip; Lynch, Jason A.; Geiss, Christoph; Stefanova, Vania

    2017-03-01

    The late-Quaternary paleoenvironmental history of the western Hudson Bay region of Subarctic Canada is poorly constrained. Here, we present a regional overview of the post-glacial history of eight lakes which span the forest-tundra biome in northern Manitoba. We show that during the penultimate drainage phase of Lake Agassiz the lake water had an estimated pH of ∼6.0, with abundant quillwort (Isöetes spp.) along the lakeshore and littoral zone and some floating green algae (Botryococcus spp. and Pediastrum sp.). Based on multiple sediment proxies, modern lake ontogeny in the region commenced at ∼7500 cal yrs BP. Pioneering diatom communities were shaped by the turbid, higher alkalinity lake waters which were influenced by base cation weathering of the surrounding till following Lake Agassiz drainage. By ∼7000 cal yrs BP, soil development and Picea spp. establish and the lakes began a slow trajectory of acidification over the remaining Holocene epoch. The natural acidification of the lakes in this region is slow, on the order of several millennia for one pH unit. Each of the study lakes exhibit relatively stable aquatic communities during the Holocene Thermal Maximum, suggesting this period is a poor analogue for modern climatic changes. During the Neoglacial, the beginning of the post-Little Ice Age period represents the most significant climatic event to impact the lakes of N. Manitoba. In the context of regional lake histories, the rate of diatom floristic change in the last 200-300 years is unprecedented, with the exception of post-glacial lake ontogeny in some of the lakes. For nearly the entire history of the lakes in this region, there is a strong linkage between landscape development and the aquatic ecosystems; however this relationship appears to become decoupled or less strong in the post-LIA period. Significant 20th century changes in the aquatic ecosystem cannot be explained wholly by changes in the terrestrial ecosystem, suggesting that future

  19. Central Chile

    Science.gov (United States)

    2002-01-01

    The beginning of spring in central Chile looked like this to SeaWiFS. The snow-covered Andes mark the country's eastern border, and phytoplankton blooms and river sediment plumes fill the waters off its west coast. A large eddy due west of Concepcion is highlighted by the phytoplankton it contains.

  20. Afrique Centrale

    African Journals Online (AJOL)

    PR BOKO

    (Afrique Centrale) : peuplement de protozoaires ciliés et macro invertébrés ... Le lac d'Obili est un écosystème aquatique situé en plein cœur de Yaoundé en ...... électrique des eaux est assez stable, autour de 200 ; ce qui suppose que la ...

  1. Integrative mining of traditional Chinese medicine literature and MEDLINE for functional gene networks.

    Science.gov (United States)

    Zhou, Xuezhong; Liu, Baoyan; Wu, Zhaohui; Feng, Yi

    2007-10-01

    The amount of biomedical data in different disciplines is growing at an exponential rate. Integrating these significant knowledge sources to generate novel hypotheses for systems biology research is difficult. Traditional Chinese medicine (TCM) is a completely different discipline, and is a complementary knowledge system to modern biomedical science. This paper uses a significant TCM bibliographic literature database in China, together with MEDLINE, to help discover novel gene functional knowledge. We present an integrative mining approach to uncover the functional gene relationships from MEDLINE and TCM bibliographic literature. This paper introduces TCM literature (about 50,000 records) as one knowledge source for constructing literature-based gene networks. We use the TCM diagnosis, TCM syndrome, to automatically congregate the related genes. The syndrome-gene relationships are discovered based on the syndrome-disease relationships extracted from TCM literature and the disease-gene relationships in MEDLINE. Based on the bubble-bootstrapping and relation weight computing methods, we have developed a prototype system called MeDisco/3S, which has name entity and relation extraction, and online analytical processing (OLAP) capabilities, to perform the integrative mining process. We have got about 200,000 syndrome-gene relations, which could help generate syndrome-based gene networks, and help analyze the functional knowledge of genes from syndrome perspective. We take the gene network of Kidney-Yang Deficiency syndrome (KYD syndrome) and the functional analysis of some genes, such as CRH (corticotropin releasing hormone), PTH (parathyroid hormone), PRL (prolactin), BRCA1 (breast cancer 1, early onset) and BRCA2 (breast cancer 2, early onset), to demonstrate the preliminary results. The underlying hypothesis is that the related genes of the same syndrome will have some biological functional relationships, and will constitute a functional network. This paper presents

  2. Calibration of a biome-biogeochemical cycles model for modeling the net primary production of teak forests through inverse modeling of remotely sensed data

    Science.gov (United States)

    Imvitthaya, Chomchid; Honda, Kiyoshi; Lertlum, Surat; Tangtham, Nipon

    2011-01-01

    In this paper, we present the results of a net primary production (NPP) modeling of teak (Tectona grandis Lin F.), an important species in tropical deciduous forests. The biome-biogeochemical cycles or Biome-BGC model was calibrated to estimate net NPP through the inverse modeling approach. A genetic algorithm (GA) was linked with Biome-BGC to determine the optimal ecophysiological model parameters. The Biome-BGC was calibrated by adjusting the ecophysiological model parameters to fit the simulated LAI to the satellite LAI (SPOT-Vegetation), and the best fitness confirmed the high accuracy of generated ecophysioligical parameter from GA. The modeled NPP, using optimized parameters from GA as input data, was evaluated using daily NPP derived by the MODIS satellite and the annual field data in northern Thailand. The results showed that NPP obtained using the optimized ecophysiological parameters were more accurate than those obtained using default literature parameterization. This improvement occurred mainly because the model's optimized parameters reduced the bias by reducing systematic underestimation in the model. These Biome-BGC results can be effectively applied in teak forests in tropical areas. The study proposes a more effective method of using GA to determine ecophysiological parameters at the site level and represents a first step toward the analysis of the carbon budget of teak plantations at the regional scale.

  3. Using co-occurrence network structure to extract synonymous gene and protein names from MEDLINE abstracts

    Directory of Open Access Journals (Sweden)

    Spackman K

    2005-04-01

    Full Text Available Abstract Background Text-mining can assist biomedical researchers in reducing information overload by extracting useful knowledge from large collections of text. We developed a novel text-mining method based on analyzing the network structure created by symbol co-occurrences as a way to extend the capabilities of knowledge extraction. The method was applied to the task of automatic gene and protein name synonym extraction. Results Performance was measured on a test set consisting of about 50,000 abstracts from one year of MEDLINE. Synonyms retrieved from curated genomics databases were used as a gold standard. The system obtained a maximum F-score of 22.21% (23.18% precision and 21.36% recall, with high efficiency in the use of seed pairs. Conclusion The method performs comparably with other studied methods, does not rely on sophisticated named-entity recognition, and requires little initial seed knowledge.

  4. Evaluating the MEDLINE Core Clinical Journals filter: data-driven evidence assessing clinical utility.

    Science.gov (United States)

    Klein-Fedyshin, Michele; Ketchum, Andrea M; Arnold, Robert M; Fedyshin, Peter J

    2014-12-01

    MEDLINE offers the Core Clinical Journals filter to limit to clinically useful journals. To determine its effectiveness for searching and patient-centric decision making, this study compared literature used for Morning Report in Internal Medicine with journals in the filter. An EndNote library with references answering 327 patient-related questions during Morning Report from 2007 to 2012 was exported to a file listing variables including designated Core Clinical Journal, Impact Factor, date used and medical subject. Bradford's law of scattering was applied ranking the journals and reflecting their clinical utility. Recall (sensitivity) and precision of the Core Morning Report journals and non-Core set was calculated. This study applied bibliometrics to compare the 628 articles used against these criteria to determine journals impacting decision making. Analysis shows 30% of clinically used articles are from the Core Clinical Journals filter and 16% of the journals represented are Core titles. When Bradford-ranked, 55% of the top 20 journals are Core. Articles sources used. Among the 63 Morning Report subjects, 55 have <50% precision and 41 have <50% recall including 37 subjects with 0% precision and 0% recall. Low usage of publications within the Core Clinical Journals filter indicates less relevance for hospital-based care. The divergence from high-impact medicine titles suggests clinically valuable journals differ from academically important titles. With few subjects demonstrating high recall or precision, the MEDLINE Core Clinical Journals filter may require a review and update to better align with current clinical needs. © 2014 John Wiley & Sons, Ltd.

  5. Strategies to optimize MEDLINE and EMBASE search strategies for anesthesiology systematic reviews. An experimental study.

    Science.gov (United States)

    Volpato, Enilze de Souza Nogueira; Betini, Marluci; Puga, Maria Eduarda; Agarwal, Arnav; Cataneo, Antônio José Maria; Oliveira, Luciane Dias de; Bazan, Rodrigo; Braz, Leandro Gobbo; Pereira, José Eduardo Guimarães; El Dib, Regina

    2018-01-15

    A high-quality electronic search is essential for ensuring accuracy and comprehensiveness among the records retrieved when conducting systematic reviews. Therefore, we aimed to identify the most efficient method for searching in both MEDLINE (through PubMed) and EMBASE, covering search terms with variant spellings, direct and indirect orders, and associations with MeSH and EMTREE terms (or lack thereof). Experimental study. UNESP, Brazil. We selected and analyzed 37 search strategies that had specifically been developed for the field of anesthesiology. These search strategies were adapted in order to cover all potentially relevant search terms, with regard to variant spellings and direct and indirect orders, in the most efficient manner. When the strategies included variant spellings and direct and indirect orders, these adapted versions of the search strategies selected retrieved the same number of search results in MEDLINE (mean of 61.3%) and a higher number in EMBASE (mean of 63.9%) in the sample analyzed. The numbers of results retrieved through the searches analyzed here were not identical with and without associated use of MeSH and EMTREE terms. However, association of these terms from both controlled vocabularies retrieved a larger number of records than did the use of either one of them. In view of these results, we recommend that the search terms used should include both preferred and non-preferred terms (i.e. variant spellings and direct/indirect order of the same term) and associated MeSH and EMTREE terms, in order to develop highly-sensitive search strategies for systematic reviews.

  6. Testing search strategies for systematic reviews in the Medline literature database through PubMed.

    Science.gov (United States)

    Volpato, Enilze S N; Betini, Marluci; El Dib, Regina

    2014-04-01

    A high-quality electronic search is essential in ensuring accuracy and completeness in retrieved records for the conducting of a systematic review. We analysed the available sample of search strategies to identify the best method for searching in Medline through PubMed, considering the use or not of parenthesis, double quotation marks, truncation and use of a simple search or search history. In our cross-sectional study of search strategies, we selected and analysed the available searches performed during evidence-based medicine classes and in systematic reviews conducted in the Botucatu Medical School, UNESP, Brazil. We analysed 120 search strategies. With regard to the use of phrase searches with parenthesis, there was no difference between the results with and without parenthesis and simple searches or search history tools in 100% of the sample analysed (P = 1.0). The number of results retrieved by the searches analysed was smaller using double quotations marks and using truncation compared with the standard strategy (P = 0.04 and P = 0.08, respectively). There is no need to use phrase-searching parenthesis to retrieve studies; however, we recommend the use of double quotation marks when an investigator attempts to retrieve articles in which a term appears to be exactly the same as what was proposed in the search form. Furthermore, we do not recommend the use of truncation in search strategies in the Medline via PubMed. Although the results of simple searches or search history tools were the same, we recommend using the latter.

  7. Ontology-Driven Search and Triage: Design of a Web-Based Visual Interface for MEDLINE.

    Science.gov (United States)

    Demelo, Jonathan; Parsons, Paul; Sedig, Kamran

    2017-02-02

    Diverse users need to search health and medical literature to satisfy open-ended goals such as making evidence-based decisions and updating their knowledge. However, doing so is challenging due to at least two major difficulties: (1) articulating information needs using accurate vocabulary and (2) dealing with large document sets returned from searches. Common search interfaces such as PubMed do not provide adequate support for exploratory search tasks. Our objective was to improve support for exploratory search tasks by combining two strategies in the design of an interactive visual interface by (1) using a formal ontology to help users build domain-specific knowledge and vocabulary and (2) providing multi-stage triaging support to help mitigate the information overload problem. We developed a Web-based tool, Ontology-Driven Visual Search and Triage Interface for MEDLINE (OVERT-MED), to test our design ideas. We implemented a custom searchable index of MEDLINE, which comprises approximately 25 million document citations. We chose a popular biomedical ontology, the Human Phenotype Ontology (HPO), to test our solution to the vocabulary problem. We implemented multistage triaging support in OVERT-MED, with the aid of interactive visualization techniques, to help users deal with large document sets returned from searches. Formative evaluation suggests that the design features in OVERT-MED are helpful in addressing the two major difficulties described above. Using a formal ontology seems to help users articulate their information needs with more accurate vocabulary. In addition, multistage triaging combined with interactive visualizations shows promise in mitigating the information overload problem. Our strategies appear to be valuable in addressing the two major problems in exploratory search. Although we tested OVERT-MED with a particular ontology and document collection, we anticipate that our strategies can be transferred successfully to other contexts.

  8. 改进Biome-BGC模型模拟哈佛森林地区水、碳通量%Simulation of water and carbon fluxes in Harvard forest area by using improved BiomeBGC model.

    Institute of Scientific and Technical Information of China (English)

    张廷龙; 孙睿; 胡波; 冯丽超; 张荣华

    2011-01-01

    Biome-BGC模型通过耦合植被、土壤与大气间的水分与CO2交换过程,实现植被生产力的模拟,但土壤水平衡模块的不够完善,导致在长时间无降水情况下植被生产力模拟存在较大误差.针对这一问题,本文对Biome-BGC模型中土壤水分胁迫气孔导度方程、蒸散计算公式及土壤水分流失过程等3方面进行了改进和调整,利用改进的Biome-BGC模型模拟美国哈佛森林地区蒸散、植被生产力,并与地面通量观测值进行了比较.结果表明,改进后模拟精度有明显的提高,蒸散、植被生态系统生产力(NEE)与观测值间的决定系数分别由0.483和0.658提高到0.617和O.813,蒸散逐年均方根误差平均下降了48.7%,NEE逐年误差平方和平均下降了39.8%.改进后的模型模拟结果更接近观测值.%Using Biome-BGC model can simulate vegetation productivity through the coupling of water and CO2 exchange processes between vegetation, soil and atmosphere, but the soil water balance module is not perfect enough, leading to a large deviation between simulated and observed values under condition of a long time no precipitation. Aiming at this problem, this paper improved and adjusted the equation of stomatal conductance stressed by soil water, the calculation formula of evapotranspiration, and the process of soil water loss in Biome-BGC model. Using this improved model, the evapotranspiration and vegetation productivity in Harvard Forest area were simulated, and compared with field observations. The accuracy of simulated results by the improved model enhanced obviously, with the evapotranspiration R between simulated and observed values increased from 0. 483 to 0. 617, NEE R2 increased from 0. 658 to 0. 813, root mean square error (RMSE) of annual evapotranspiration decreased averagely by 48. 7% , and annual sum squared error ( ASSE) of NEE decreased averagely by 39. 8% , which suggested that the simulated results by using the improved model

  9. Europa central

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    Karel BARTOSEK

    2010-02-01

    Full Text Available La investigación francesa continúa interesándose por Europa Central. Desde luego, hay límites a este interés en el ambiente general de mi nueva patria: en la ignorancia, producto del largo desinterés de Francia por este espacio después de la Segunda Guerra Mundial, y en el comportamiento y la reflexión de la clase política y de los medios de comunicación (una anécdota para ilustrar este ambiente: durante la preparación de nuestro coloquio «Refugiados e inmigrantes de Europa Central en el movimiento antifascista y la Resistencia en Francia, 1933-1945», celebrado en París en octubre de 1986, el problema de la definición fue planteado concreta y «prácticamente». ¡Y hubo entonces un historiador eminente, para quién Alemania no formaría parte de Europa Central!.

  10. Uso da rugoscopia palatina como ferramenta biométrica: um estudo populacional em Niterói-RJ, Brasil

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    Igor Iuco CASTRO-SILVA

    Full Text Available Introdução: Pesquisas por métodos biométricos auxiliares em perícias têm crescido na Odontologia Legal. Objetivo: Este estudo avaliou a eficácia da rugoscopia palatina na identificação humana. Material e método: Foram utilizados 184 modelos de gesso de estudantes voluntários em Niterói-RJ, para delineamento de suas rugosidades palatinas, sendo classificadas segundo quantidade, direção (sistema de Carrea e formato individual (sistema de Silva, e comparadas às variáveis demográficas sexo, cor da pele e idade. A análise estatística foi realizada com o teste qui-quadrado para amostras independentes, considerando-se p<0,05. Resultado: Houve maior prevalência de 2-7 rugas em homens. O tipo IV de Carrea e o tipo 1 de Silva foram mais evidentes, porém sem diferenças intergrupos significativas, de acordo com as variáveis propostas. Conclusão: A rugoscopia palatina é uma ferramenta biométrica viável e fornece informações morfológicas individuais relevantes, embora sua análise cega e em tempo único não exiba acurácia na estratificação populacional.

  11. The biogeographic origin of a radiation of trees in Madagascar: implications for the assembly of a tropical forest biome.

    Science.gov (United States)

    Federman, Sarah; Dornburg, Alex; Downie, Alexander; Richard, Alison F; Daly, Douglas C; Donoghue, Michael J

    2015-10-05

    Madagascar's rain forests are characterized by extreme and uneven patterns of species richness and endemicity, the biogeographic and evolutionary origins of which are poorly understood. Here we use a time-calibrated phylogeny of a dominant group of trees in Madagascar's eastern rain forests, Canarium, and related Burseraceae (Canarieae), to test biogeographic hypotheses regarding the origin and radiation of the flora of this unique biome. Our findings strongly support the monophyly of Malagasy Canarium, suggesting that this clade represents a previously undocumented in situ radiation. Contrary to expectations of dispersal from Africa during the Oligocene, concurrent with the formation of Madagascar's rain forest biome, our analyses support a late Miocene origin for Malagasy Canarium, probably by long distance dispersal from Southeast Asia. Our study illustrates the importance of considering long distance dispersal as a viable explanation for clades with pantropical distributions diversifying subsequent to the Oligocene, and it highlights the formation of the Indo-Australian Archipelago and associated fast-moving equatorial surface currents, suggesting an under-appreciated evolutionary link among tropical centers of endemism. We postulate that the relatively recent establishment and radiation of Canarium in Madagascar may have been facilitated by the highly stochastic climates associated with these forest ecosystems.

  12. Land-use change and soil type are drivers of fungal and archaeal communities in the Pampa biome.

    Science.gov (United States)

    Lupatini, Manoeli; Jacques, Rodrigo Josemar Seminoti; Antoniolli, Zaida Inês; Suleiman, Afnan Khalil Ahmad; Fulthorpe, Roberta R; Roesch, Luiz Fernando Würdig

    2013-02-01

    The current study aimed to test the hypothesis that both land-use change and soil type are responsible for the major changes in the fungal and archaeal community structure and functioning of the soil microbial community in Brazilian Pampa biome. Soil samples were collected at sites with different land-uses (native grassland, native forest, Eucalyptus and Acacia plantation, soybean and watermelon field) and in a typical toposequence in Pampa biome formed by Paleudult, Albaqualf and alluvial soils. The structure of soil microbial community (archaeal and fungal) was evaluated by ribosomal intergenic spacer analysis and soil functional capabilities were measured by microbial biomass carbon and metabolic quotient. We detected different patterns in microbial community driven by land-use change and soil type, showing that both factors are significant drivers of fungal and archaeal community structure and biomass and microbial activity. Fungal community structure was more affected by land-use and archaeal community was more affected by soil type. Irrespective of the land-use or soil type, a large percentage of operational taxonomic unit were shared among the soils. We accepted the hypothesis that both land-use change and soil type are drivers of archaeal and fungal community structure and soil functional capabilities. Moreover, we also suggest the existence of a soil microbial core.

  13. Hydrology of a Water‐Limited Forest under Climate Change Scenarios: The Case of the Caatinga Biome, Brazil

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    Everton Alves Rodrigues Pinheiro

    2017-02-01

    Full Text Available Given the strong interactions between climate and vegetation, climate change effects on natural and agricultural ecosystems are common objects of research. Reduced water availability is predicted to take place across large regions of the globe, including Northeastern Brazil. The Caatinga, a complex tropical water‐limited ecosystem and the only exclusively Brazilian biome, prevails as the main natural forest of this region. The aim of this study was to examine the soil‐water balance for this biome under a climate‐warming scenario and with reduced rainfall. Climate change projections were assessed from regional circulation models earlier applied to the Brazilian territory. A statistical climate data generator was used to compose a synthetic weather dataset, which was later integrated into a hydrological model. Compared to simulations with current climate for the same site, under the scenario with climate change, transpiration was enhanced by 36%, and soilwater evaporation and interception were reduced by 16% and 34%, respectively. The greatest change in soil‐water components was observed for deep drainage, accounting only for 2% of the annual rainfall. Soil‐plant‐atmosphere fluxes seem to be controlled by the top layer (0.0-0.2 m, which provides 80% of the total transpiration, suggesting that the Caatinga forest may become completely soil‐water pulse dominated under scenarios of reduced water availability.

  14. Ética e pesquisa biomédica em sociedades indígenas no Brasil

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    Coimbra Jr. Carlos E. A.

    1996-01-01

    Full Text Available Este trabalho discute questões relativas à ética da investigação biomédica em populações indígenas brasileiras, em particular no que tange à obtenção de consentimento pós-informacional em pesquisas que envolvam a coleta de amostras biológicas. Enfatiza-se que nada há de específico na legislação atual com respeito à pesquisa biomédica nestas populações. A partir de uma perspectiva antropológica, os autores analisam algumas das dificuldades para a obtenção do consentimento "realmente" informado. Chama-se atenção para a importância das discussões sobre ética em pesquisa face a possibilidade de utilização comercial de amostras biológicas, como exemplificado pelo atual debate sobre patenteamento de material genético humano.

  15. Stormflow influence on nutrient dynamics in micro-catchments under contrasting land use in the Cerrado and Amazon Biomes, Brazil

    Science.gov (United States)

    Edelmann, Katharina; Nóbrega, Rodolfo L. B.; Gerold, Gerhard

    2017-04-01

    The Amazon and Cerrado biomes in Brazil have been under intense land-use change during the past few decades. The conversion of native vegetation to pastures and croplands has caused impacts on hydrological processes in these biomes, resulting in increased streamflow and nutrient fluxes. Our aim was to compare the nutrient dynamics during stormflow events in two pairs of adjacent micro-catchments with similar physical characteristics under contrasting land use, i.e. native vegetation (rainforest or cerrado) and pasture. One pair of catchments was located in the Amazon and the other in the Cerrado, both on the Amazon Agricultural Frontier in the Brazilian states of Mato Grosso and Pará. We collected hydrological and hydrochemical data on 50 stormflow events on a sub-hourly resolution during the wet seasons of 2013 and 2014. We compared the dynamics of total inorganic carbon (TIC), total organic carbon (TOC), dissolved organic carbon (DOC), nitrate (NO3), calcium (Ca), potassium (K), and magnesium (Mg) in different hydrograph parts, i.e. rising limb, peak and recession limb, between the catchments within the same biome. For the Cerrado biome, our findings show that the nutrient concentrations in the stormflows were higher in the pasture catchment than in the cerrado catchment. In the Amazon biome, we found an inverse relationship with higher concentrations in the forest catchment than in the pasture catchment, except for TIC and K. Most nutrients in the cerrado catchment had the highest concentrations in the rising limb. Mg, however, reached highest concentrations during peak discharge, and lowest in the recession limb. In the adjacent pasture catchment, in contrast, the highest nutrient concentrations were observed during the peak discharge (TIC, TOC, Ca) or the recession limb (DOC, NO3, K, Mg) with lowest in the rising limb, except for NO3, which showed the lowest concentrations during peak discharge. In the Amazon forest catchment, the peak discharge showed the

  16. Are There Consistent Grazing Indicators in Drylands? Testing Plant Functional Types of Various Complexity in South Africa’s Grassland and Savanna Biomes

    Science.gov (United States)

    Linstädter, Anja; Schellberg, Jürgen; Brüser, Katharina; Moreno García, Cristian A.; Oomen, Roelof J.; du Preez, Chris C.; Ruppert, Jan C.; Ewert, Frank

    2014-01-01

    Despite our growing knowledge on plants’ functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs) with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa’s grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs). Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses) and two-trait PFTs (e.g. perennial grasses) performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold) had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may also be

  17. Are there consistent grazing indicators in Drylands? Testing plant functional types of various complexity in South Africa's Grassland and Savanna Biomes.

    Directory of Open Access Journals (Sweden)

    Anja Linstädter

    Full Text Available Despite our growing knowledge on plants' functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa's grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs. Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses and two-trait PFTs (e.g. perennial grasses performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may

  18. Are there consistent grazing indicators in Drylands? Testing plant functional types of various complexity in South Africa's Grassland and Savanna Biomes.

    Science.gov (United States)

    Linstädter, Anja; Schellberg, Jürgen; Brüser, Katharina; Moreno García, Cristian A; Oomen, Roelof J; du Preez, Chris C; Ruppert, Jan C; Ewert, Frank

    2014-01-01

    Despite our growing knowledge on plants' functional responses to grazing, there is no consensus if an optimum level of functional aggregation exists for detecting grazing effects in drylands. With a comparative approach we searched for plant functional types (PFTs) with a consistent response to grazing across two areas differing in climatic aridity, situated in South Africa's grassland and savanna biomes. We aggregated herbaceous species into PFTs, using hierarchical combinations of traits (from single- to three-trait PFTs). Traits relate to life history, growth form and leaf width. We first confirmed that soil and grazing gradients were largely independent from each other, and then searched in each biome for PFTs with a sensitive response to grazing, avoiding confounding with soil conditions. We found no response consistency, but biome-specific optimum aggregation levels. Three-trait PFTs (e.g. broad-leaved perennial grasses) and two-trait PFTs (e.g. perennial grasses) performed best as indicators of grazing effects in the semi-arid grassland and in the arid savanna biome, respectively. Some PFTs increased with grazing pressure in the grassland, but decreased in the savanna. We applied biome-specific grazing indicators to evaluate if differences in grazing management related to land tenure (communal versus freehold) had effects on vegetation. Tenure effects were small, which we mainly attributed to large variability in grazing pressure across farms. We conclude that the striking lack of generalizable PFT responses to grazing is due to a convergence of aridity and grazing effects, and unlikely to be overcome by more refined classification approaches. Hence, PFTs with an opposite response to grazing in the two biomes rather have a unimodal response along a gradient of additive forces of aridity and grazing. The study advocates for hierarchical trait combinations to identify localized indicator sets for grazing effects. Its methodological approach may also be useful

  19. Data resources for range-wide assessment of livestock grazing across the sagebrush biome

    Science.gov (United States)

    Assal, T.J.; Veblen, K.E.; Farinha, M.A.; Aldridge, Cameron L.; Casazza, Michael L.; Pyke, D.A.

    2012-01-01

    The data contained in this series were compiled, modified, and analyzed for the U.S. Geological Survey (USGS) report "Range-Wide Assessment of Livestock Grazing Across the Sagebrush Biome." This report can be accessed through the USGS Publications Warehouse (online linkage: http://pubs.usgs.gov/of/2011/1263/). The dataset contains spatial and tabular data related to Bureau of Land Management (BLM) Grazing Allotments. We reviewed the BLM national grazing allotment spatial dataset available from the GeoCommunicator National Integrated Land System (NILS) website in 2007 (http://www.geocommunicator.gov). We identified several limitations in those data and learned that some BLM State and/or field offices had updated their spatial data to rectify these limitations, but maintained the data outside of NILS. We contacted appropriate BLM offices (State or field, 25 in all) to obtain the most recent data, assessed the data, established a data development protocol, and compiled data into a topologically enforced dataset throughout the area of interest for this project (that is, the pre-settlement distribution of Greater Sage-Grouse in the Western United States). The final database includes three spatial datasets: Allotments (BLM Grazing Allotments), OUT_Polygons (nonallotment polygons used to ensure topology), and Duplicate_Polygon_Allotments. See Appendix 1 of the aforementioned report for complete methods. The tabular data presented here consists of information synthesized by the Land Health Standard (LHS) analysis (Appendix 2), and data obtained from the BLM Rangeland Administration System (http://www.blm.gov/ras/). In 2008, available LHS data for all allotments in all regions were compiled by BLM in response to a Freedom of Information Act (FOIA) request made by a private organization. The BLM provided us with a copy of these data. These data provided three major types of information that were of interest: (1) date(s) (if any) of the most recent LHS evaluation for each

  20. Determining the resilience of carbon dynamics in semi-arid biomes of the Southwestern US to severe drought and altered rainfall patterns

    Science.gov (United States)

    Litvak, M. E.; Krofcheck, D. J.; Hilton, T. W.; Fox, A. M.; Osuna, J. L.

    2011-12-01

    Water is critically important for biotic processes in semi-arid ecosystems and 2011 is developing as one of the most severe drought years on record for many parts of the Southwestern US. To quantify the impact of this severe drought on regional carbon and energy balance, we need a more detailed understanding of how water limitation alters ecosystem processes across a range of semi-arid biomes. We quantified the impact of severe drought and changes in both the quantity and distribution of precipitation on ecosystem biotic structure and function across the range of biomes represented in the NM elevation gradient network (desert grassland, creosote shrubland, juniper savanna, piñon-juniper woodland, ponderosa pine forest and subalpine mixed conifer forest). We compared how daily, seasonal and annual carbon and energy balance and their components in each of these biomes respond to changes in rainfall patterns using continuous measurements of carbon, water and energy exchange and associated measurements in each of these biomes during a 5 year period (2006-2011) that included a severe drought, and large variability in both winter precipitation and the timing and intensity of the monsoon. To understand the underlying mechanisms, we used time series of radiation absorbed by vegetation, surface albedo, soil moisture storage, phenology, gross primary productivity (GPP), ecosystem respiration (Re), and WorldView-2 images acquired pre- and post-monsoon in each of these biomes. In all of the biomes except the desert grassland site, the strength and timing of both winter and monsoon precipitation are important controls over carbon and energy dynamics in this region, though we see site-specific sensitivities across the elevation gradient. Over the past 5 years, carbon dynamics in the desert grassland site appears to be decoupled from winter precipitation. In addition, carbon dynamics in disturbed grassland and pinon-juniper ecosystems were more sensitive to severe drought than