WorldWideScience

Sample records for ecosystem manipulation experiments

  1. CLIMAITE - a three factor climate change ecosystem manipulation experiment.

    Science.gov (United States)

    Mikkelsen, T. N.; Beier, C.; Albert, K.; Ro-Poulsen, H.

    2007-12-01

    The Danish multi factorial climate change effects on vegetation experiment (Climaite) have now been conducted for two years on semi-natural grassland. The day time [CO2], night time temperature and precipitation (drought) have been altered, according to a regional climate change model for the year 2075, in a full factorial split plot design. The manipulated area for each treatment is 7 m2 and it is replicated 6 times. The CO2 and temperature treatments have been conducted continuously except for periods with snow cover. The CO2 is enhanced to 510 ppm via a FACE system based on concentrated CO2 released upwind under pressure. The control of the [CO2] varies with wind speed and irradiation, but during 50 percent of the fumigation period the target concentration was kept within +/-5 percent. The temperature treatment is conducted via infrared reflective curtains covering the plots during night time, and the warming of plants and soil depends of the day irradiation, night time wind speed and factors related to seasonality. In general, the air temperature is increased during night time with 1-2 C° and negligible during the day. The soil temperature in 5 cm depth is enhanced to 0.3 - 0.6 C° during night and day. The artificial summer droughts lasted about one month and differences in soil water content were developed over time. By the end of the treatment the èv content in the soil was as low as 0.06 m3 m-3 compared to 0.20 m3 m-3 in the control. Numerous physical and biological parameters in the grassland ecosystem have been measured and several are responding to the changed environment. After 9 months of exposure enhanced [CO2] stimulated the net photosynthesis (based on dry weight) in both of the domination plant species Calluna Vulgaris and Deschampsia flexuosa. When the plants were exposed to short term saturated [CO2] during gasexchange measurements the long term CO2 treated plants also had the highest photosynthesis rate, meaning that the plants were not

  2. Dryland ecosystem responses to precipitation extremes and wildfire at a long-term rainfall manipulation experiment

    Science.gov (United States)

    Brown, R. F.; Collins, S. L.

    2017-12-01

    Climate is becoming increasingly more variable due to global environmental change, which is evidenced by fewer, but more extreme precipitation events, changes in precipitation seasonality, and longer, higher severity droughts. These changes, combined with a rising incidence of wildfire, have the potential to strongly impact net primary production (NPP) and key biogeochemical cycles, particularly in dryland ecosystems where NPP is sequentially limited by water and nutrient availability. Here we utilize a ten-year dataset from an ongoing long-term field experiment established in 2007 in which we experimentally altered monsoon rainfall variability to examine how our manipulations, along with naturally occurring events, affect NPP and associated biogeochemical cycles in a semi-arid grassland in central New Mexico, USA. Using long-term regional averages, we identified extremely wet monsoon years (242.8 mm, 2013), and extremely dry monsoon years (86.0 mm, 2011; 80.0 mm, 2015) and water years (117.0 mm, 2011). We examined how changes in precipitation variability and extreme events affected ecosystem processes and function particularly in the context of ecosystem recovery following a 2009 wildfire. Response variables included above- and below-ground plant biomass (ANPP & BNPP) and abundance, soil nitrogen availability, and soil CO2 efflux. Mean ANPP ranged from 3.6 g m-2 in 2011 to 254.5 g m-2 in 2013, while BNPP ranged from 23.5 g m-2 in 2015 to 194.2 g m-2 in 2013, demonstrating NPP in our semi-arid grassland is directly linked to extremes in both seasonal and annual precipitation. We also show increased nitrogen deposition positively affects NPP in unburned grassland, but has no significant impact on NPP post-fire except during extremely wet monsoon years. While soil respiration rates reflect lower ANPP post-fire, patterns in CO2 efflux have not been shown to change significantly in that efflux is greatest following large precipitation events preceded by longer drying

  3. Large and Small Scale Nitrogen and Phosporous Manipulation Experiment in a Tree-Grass Ecosystem: first year of results

    Science.gov (United States)

    Migliavacca, Mirco; Perez Priego, Oscar; El-Madany, Tarek; Guan, JinHong; Carrara, Arnaud; Fava, Francesco; Moreno, Gerardo; Kolle, Olaf; Rossini, Micol; Schrumpf, Marion; Julitta, Tommaso; Reichstein, Markus

    2015-04-01

    Recent studies have shown how human induced N/P imbalances affect essential ecosystem processes (e.g. photosynthesis, plant growth rate, respiration), and might be particularly important in water-limited ecosystems. In this contribution we will present the experimental design and the results of the first year of two nutrient manipulation experiments conducted at different spatial scale. In the first experiment a cluster of 2 eddy covariance (EC) flux towers has been set up beside a long-term EC site (Las Majadas del Tietar, Spain). Sites are selected in a way to have similar nutrient conditions, canopy structure, and stoichiometry of the different vegetation and soil pools. Two of the three footprints will be manipulated with addition of N and NP fertilizer at the beginning of 2015. The comparison of the three EC flux towers installed during the first year of the experiment (without fertilization) will be shown. We characterized the differences of the responses of carbon and water fluxes measured by the EC systems to environmental drivers, and structural and biophysical properties of the canopy. The second experiment was conducted over a Mediterranean grassland, where 16 plots of 10x10 meters that were manipulated by adding nutrient (N, P, and NP). The overall objective was to investigate the response of the gross primary productivity (GPP), assessed by using transparent transient-state canopy chambers, to different nutrient availability. The second objective was to evaluate the capability of hyperspectral data and Solar induced fluorescence to track short- and long-term GPP and light use efficiency variation under different N and P fertilization treatments. Spectral vegetation indices (VIs) were acquired manually using high resolution spectrometers (HR4000, OceanOptics, USA) along a phenological cycle. The VIs used included photochemical reflectance index (PRI), MERIS terrestrial-chlorophyll index (MTCI) and normalized difference vegetation index (NDVI). Solar

  4. Manipulations to regenerate aspen ecosystems

    Science.gov (United States)

    Wayne D. Shepperd

    2001-01-01

    Vegetative regeneration of aspen can be initiated through manipulations that provide hormonal stimulation, proper growth environment, and sucker protection - the three elements of the aspen regeneration triangle. The correct course of action depends upon a careful evaluation of the size, vigor, age, and successional status of the existing clone. Soils and site...

  5. The Experimental Lakes Area: Over 45 Years of Whole Ecosystem Monitoring and Manipulation Experiments and a Focus on the Future

    Science.gov (United States)

    Emmerton, C. A.

    2015-12-01

    The IISD Experimental Lakes Area is a unique facility which has existed since 1968 and consists of 58 lakes and their watersheds set aside for research purposes. The IISD-ELA also boasts an on-site water chemistry lab, accommodations and facilities for up to 60 personnel. Since its inception in 1968 over 50 whole ecosystem experiments have been conducted at the ELA including eutrophication, acidification of lakes, environmental mercury fates, hydro-electric reservoir impacts and much more. The recent partnership between IISD and ELA has allowed ELA to refocus on freshwater research and policy development in a time where the preservation of the earth's most precious resource is of the utmost concern. In addition to water quality monitoring, the ELA is also focused on autotrophic ecology, zooplankton community structures, fish population and behaviour and food-web interactions. Monitoring all of these disciplines and their inter-relationships gives the research facility a unique perspective and along with the long term dataset stretching back to 1968 the ELA can look at historical records to monitor long term changes in the environment.

  6. Tree manipulation experiment

    Science.gov (United States)

    Nishina, K.; Takenaka, C.; Ishizuka, S.; Hashimoto, S.; Yagai, Y.

    2012-12-01

    Some forest operations such as thinning and harvesting management could cause changes in N cycling and N2O emission from soils, since thinning and harvesting managements are accompanied with changes in aboveground environments such as an increase of slash falling and solar radiation on the forest floor. However, a considerable uncertainty exists in effects of thinning and harvesting on N2O fluxes regarding changes in belowground environments by cutting trees. To focus on the effect of changes in belowground environments on the N2O emissions from soils, we conducted a tree manipulation experiment in Japanese cedar (Cryptomeria japonica) stand without soil compaction and slash falling near the chambers and measured N2O flux at 50 cm and 150 cm distances from the tree trunk (stump) before and after cutting. We targeted 5 trees for the manipulation and established the measurement chambers to the 4 directions around each targeted tree relative to upper slope (upper, left, right, lower positions). We evaluated the effect of logging on the emission by using hierarchical Bayesian model. HB model can evaluate the variability in observed data and their uncertainties in the estimation with various probability distributions. Moreover, the HB model can easily accommodate the non-linear relationship among the N2O emissions and the environmental factors, and explicitly take non-independent data (nested structure of data) for the estimation into account by using random effects in the model. Our results showed tree cutting stimulated N2O emission from soils, and also that the increase of N2O flux depended on the distance from the trunk (stump): the increase of N2O flux at 50 cm from the trunk (stump) was greater than that of 150 cm from the trunk. The posterior simulation of the HB model indicated that the stimulation of N2O emission by tree cut- ting could reach up to 200 cm in our experimental plot. By tree cutting, the estimated N2O emission at 0-40 cm from the trunk doubled

  7. Experimental manipulation of succession in heathland ecosystems.

    NARCIS (Netherlands)

    Berendse, F.; Schmitz, M.; Visser, de W.

    1994-01-01

    An experiment was carried out in two heathland ecosystems, one dominated by Calluna vulgaris and the other by Molinia caerulea, to analyse the effects of soil organic matter accumulation and nutrient mineralization on plant species dynamics during succession. The experiment included one treatment

  8. Manipulating a stated choice experiment

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Borjesson, Maria

    2015-01-01

    This paper considers the design of a stated choice experiment intended to measure the marginal rate of substitution (MRS) between cost and an attribute such as time using a conventional logit model. Focusing the experimental design on some target MRS will bias estimates towards that value....... The paper shows why this happens. The resulting estimated MRS can then be manipulated by adapting the target MRS in the experimental design. (C) 2015 Elsevier Ltd. All rights reserved....

  9. Whole-ecosystem experimental manipulations of tropical forests

    OpenAIRE

    Fayle, Tom M; Turner, Edgar Clive; Basset, Yves; Ewers, Robert M; Reynolds, Glen; Novotny, Vojtech

    2015-01-01

    Tropical forests are highly diverse systems involving extraordinary numbers of interactions between species, with each species responding in a different way to the abiotic environment. Understanding how these systems function and predicting how they respond to anthropogenic global change is extremely challenging. We argue for the necessity of ‘whole-ecosystem’ experimental manipulations, in which the entire ecosystem is targeted, either to reveal the functioning of the...

  10. Complexity in Climate Change Manipulation Experiments

    DEFF Research Database (Denmark)

    Kreyling, Juergen; Beier, Claus

    2014-01-01

    Climate change goes beyond gradual changes in mean conditions. It involves increased variability in climatic drivers and increased frequency and intensity of extreme events. Climate manipulation experiments are one major tool to explore the ecological impacts of climate change. Until now...... variability in temperature are ecologically important. Embracing complexity in future climate change experiments in general is therefore crucial......., precipitation experiments have dealt with temporal variability or extreme events, such as drought, resulting in a multitude of approaches and scenarios with limited comparability among studies. Temperature manipulations have mainly been focused only on warming, resulting in better comparability among studies...

  11. Danish heathland manipulation experiment data in Model-Data-Fusion

    Science.gov (United States)

    Thum, Tea; Peylin, Philippe; Ibrom, Andreas; Van Der Linden, Leon; Beier, Claus; Bacour, Cédric; Santaren, Diego; Ciais, Philippe

    2013-04-01

    In ecosystem manipulation experiments (EMEs) the ecosystem is artificially exposed to different environmental conditions that aim to simulate circumstances in future climate. At Danish EME site Brandbjerg the responses of a heathland to drought, warming and increased atmospheric CO2 concentration are studied. The warming manipulation is realized by passive nighttime warming. The measurements include control plots as well as replicates for each three treatment separately and in combination. The Brandbjerg heathland ecosystem is dominated by heather and wavy hairgrass. These experiments provide excellent data for validation and development of ecosystem models. In this work we used a generic vegetation model ORCHIDEE with Model-Data-Fusion (MDF) approach. ORCHIDEE model is a process-based model that describes the exchanges of carbon, water and energy between the atmosphere and the vegetation. It can be run at different spatial scales from global to site level. Different vegetation types are described in ORCHIDEE as plant functional types. In MDF we are using observations from the site to optimize the model parameters. This enables us to assess the modelling errors and the performance of the model for different manipulation treatments. This insight will inform us whether the different processes are adequately modelled or if the model is missing some important processes. We used a genetic algorithm in the MDF. The data available from the site included measurements of aboveground biomass, heterotrophic soil respiration and total ecosystem respiration from years 2006-2008. The biomass was measured six times doing this period. The respiration measurements were done with manual chamber measurements. For the soil respiration we used results from an empirical model that has been developed for the site. This enabled us to have more data for the MDF. Before the MDF we performed a sensitivity analysis of the model parameters to different data streams. Fifteen most influential

  12. Trajectories of grassland ecosystem change in response to experimental manipulations of precipitation

    Science.gov (United States)

    Knapp, Alan; Smith, Melinda; Collins, Scott; Blair, John; Briggs, John

    2010-05-01

    Understanding and predicting the dynamics of ecological systems has always been central to Ecology. Today, ecologists recognize that in addition to natural and human-caused disturbances, a fundamentally different type of ecosystem change is being driven by the combined and cumulative effects of anthropogenic activities affecting earth's climate and biogeochemical cycles. This type of change is historically unprecedented in magnitude, and as a consequence, such alterations are leading to trajectories of change in ecological responses that differ radically from those observed in the past. Through both short- and long-term experiments, we have been trying to better understand the mechanisms and consequences of ecological change in grassland ecosystems likely to result from changes in precipitation regimes. We have manipulated a key resource for most grasslands (water) and modulators of water availability (temperature) in field experiments that vary from 1-17 years in duration, and used even longer-term monitoring data from the Konza Prairie LTER program to assess how grassland communities and ecosystems will respond to changes in water availability. Trajectories of change in aboveground net primary production (ANPP) in sites subjected to 17 years of soil water augmentation were strongly non-linear with a marked increase in the stimulation of ANPP after year 8 (from 25% to 65%). Lags in alterations in grassland community composition are posited to be responsible for the form of this trajectory of change. In contrast, responses in ANPP to chronic increases in soil moisture variability appear to have decreased over a 10-yr period of manipulation, although the net effects of more variable precipitation inputs were to reduce ANPP, alter the genetic structure of the dominant grass species, increase soil nitrogen availability and reduce soil respiration. The loss of sensitivity to increased resource variability was not reflected in adjacent plots where precipitation was

  13. Do global change experiments overestimate impacts on terrestrial ecosystems?

    DEFF Research Database (Denmark)

    Leuzinger, Sebastian; Luo, Yiqi; Beier, Claus

    2011-01-01

    In recent decades, many climate manipulation experiments have investigated biosphere responses to global change. These experiments typically examined effects of elevated atmospheric CO2, warming or drought (driver variables) on ecosystem processes such as the carbon and water cycle (response...... of the responses to decline with higher-order interactions, longer time periods and larger spatial scales. This means that on average, both positive and negative global change impacts on the biosphere might be dampened more than previously assumed....

  14. Large remote manipulator operating and maintenance experience at IEM cell

    International Nuclear Information System (INIS)

    Hicks, D.F.; McGuinness, P.W.

    1985-01-01

    The Interim Examination and Maintenance (IEM) Cell at the Fast Flux Test Facility (FFTF) has two large Electro-Mechanical Manipulators (EMM's). These manipulators are used for cell operations (processing of reactor core components) as well as general cell maintenance. From our eleven years of operation and maintenance experience with these large EMM's, we have learned many lessons concerning manipulator design. This paper describes the IEM Cell EMM design features and discusses operating and maintenance experience at the IEM Cell

  15. Multilink manipulator computer control: experience in development and commissioning

    International Nuclear Information System (INIS)

    Holt, J.E.

    1988-11-01

    This report describes development which has been carried out on the multilink manipulator computer control system. The system allows the manipulator to be driven using only two joysticks. The leading link is controlled and the other links follow its path into the reactor, thus avoiding any potential obstacles. The system has been fully commissioned and used with the Sizewell ''A'' reactor 2 Multilink T.V. manipulator. Experience of the use of the system is presented, together with recommendations for future improvements. (author)

  16. What have we learned from global change manipulative experiments in China? A meta-analysis

    OpenAIRE

    Zheng Fu; Shuli Niu; Jeffrey S. Dukes

    2015-01-01

    Although China has the largest population in the world, a faster rate of warming than the global average, and an active global change research program, results from many of the global change experiments in Chinese terrestrial ecosystems have not been included in global syntheses. Here, we specifically analyze the observed responses of carbon (C) and nitrogen (N) cycling in global change manipulative experiments in China, and compare these responses to those from other regions of the world. Mo...

  17. Ecosystem and Community Responses to Rainfall Manipulations in Shrublands Depends on Dominant Vegetation Cover

    Science.gov (United States)

    Esch, E. H.; Lipson, D.; Kim, J. B.; Cleland, E. E.

    2014-12-01

    Southern California is predicted to face decreasing precipitation with increased interannual variability in the coming century. Native shrublands in this area are increasingly invaded by exotic annual grasses, though invasion dynamics can vary by rainfall scenario, with wet years generally associated with high invasion pressure. Interplay between rainfall and invasion scenarios can influence carbon stocks and community composition. Here we asked how invasion alters ecosystem and community responses in drought versus high rainfall scenarios, as quantified by community identity, biomass production, and the normalized difference vegetation index (NDVI). To do this, we performed a rainfall manipulation experiment with paired plots dominated either by native shrubs or exotic herbaceous species, subjected to treatments of 50%, 100%, or 150% of ambient rainfall. The study site was located in a coastal sage scrub ecosystem, with patches dominated by native shrubs and exotic grasses located in San Diego County, USA. During two growing seasons, we found that native, herbaceous biomass production was significantly affected by rainfall treatment (p<0.05 for both years), though was not affected by dominant community composition. Photosynthetic biomass production of shrub species also varied by treatment (p=0.035). Exotic biomass production showed a significant interaction between dominant community composition and rainfall treatment, and both individual effects (p<0.001 for all). NDVI showed similar results, but also indicated the importance of rainfall timing on overall biomass production between years. Community composition data showed certain species, of both native and exotic identities, segregating by treatment. These results indicate that exotic species are more sensitive to rainfall, and that increased rainfall may promote greater carbon storage in annual dominated communities when compared to shrub dominated communities in high rainfall years, but with drought, this

  18. What have we learned from global change manipulative experiments in China? A meta-analysis

    Science.gov (United States)

    Fu, Zheng; Niu, Shuli; Dukes, Jeffrey S.

    2015-01-01

    Although China has the largest population in the world, a faster rate of warming than the global average, and an active global change research program, results from many of the global change experiments in Chinese terrestrial ecosystems have not been included in global syntheses. Here, we specifically analyze the observed responses of carbon (C) and nitrogen (N) cycling in global change manipulative experiments in China, and compare these responses to those from other regions of the world. Most global change factors, vegetation types, and treatment methods that have been studied or used elsewhere in the world have also been studied and applied in China. The responses of terrestrial ecosystem C and N cycles to N addition and climate warming in China are similar in both direction and intensity to those reported in global syntheses. In Chinese ecosystems as elsewhere, N addition significantly increased aboveground (AGB) and belowground biomass (BGB), litter mass, dissolved organic C, net ecosystem productivity (NEP), and gross ecosystem productivity (GEP). Warming stimulated AGB, BGB and the root-shoot ratio. Increasing precipitation accelerated GEP, NEP, microbial respiration, soil respiration, and ecosystem respiration. Our findings complement and support previous global syntheses and provide insight into regional responses to global change. PMID:26205333

  19. Manipulators

    International Nuclear Information System (INIS)

    Wilcock, P.D.

    1984-01-01

    The patent concerns a manipulator, which enables operations to be carried out remotely from the operator. The device is suitable for use in handling of radioactive materials and other hazardous liquids or gases. The specifications are given, and the movements of the manipulator arm described. (U.K.)

  20. Asymmetric responses of primary productivity to precipitation extremes: A synthesis of grassland precipitation manipulation experiments.

    Science.gov (United States)

    Wilcox, Kevin R; Shi, Zheng; Gherardi, Laureano A; Lemoine, Nathan P; Koerner, Sally E; Hoover, David L; Bork, Edward; Byrne, Kerry M; Cahill, James; Collins, Scott L; Evans, Sarah; Gilgen, Anna K; Holub, Petr; Jiang, Lifen; Knapp, Alan K; LeCain, Daniel; Liang, Junyi; Garcia-Palacios, Pablo; Peñuelas, Josep; Pockman, William T; Smith, Melinda D; Sun, Shanghua; White, Shannon R; Yahdjian, Laura; Zhu, Kai; Luo, Yiqi

    2017-10-01

    Climatic changes are altering Earth's hydrological cycle, resulting in altered precipitation amounts, increased interannual variability of precipitation, and more frequent extreme precipitation events. These trends will likely continue into the future, having substantial impacts on net primary productivity (NPP) and associated ecosystem services such as food production and carbon sequestration. Frequently, experimental manipulations of precipitation have linked altered precipitation regimes to changes in NPP. Yet, findings have been diverse and substantial uncertainty still surrounds generalities describing patterns of ecosystem sensitivity to altered precipitation. Additionally, we do not know whether previously observed correlations between NPP and precipitation remain accurate when precipitation changes become extreme. We synthesized results from 83 case studies of experimental precipitation manipulations in grasslands worldwide. We used meta-analytical techniques to search for generalities and asymmetries of aboveground NPP (ANPP) and belowground NPP (BNPP) responses to both the direction and magnitude of precipitation change. Sensitivity (i.e., productivity response standardized by the amount of precipitation change) of BNPP was similar under precipitation additions and reductions, but ANPP was more sensitive to precipitation additions than reductions; this was especially evident in drier ecosystems. Additionally, overall relationships between the magnitude of productivity responses and the magnitude of precipitation change were saturating in form. The saturating form of this relationship was likely driven by ANPP responses to very extreme precipitation increases, although there were limited studies imposing extreme precipitation change, and there was considerable variation among experiments. This highlights the importance of incorporating gradients of manipulations, ranging from extreme drought to extreme precipitation increases into future climate change

  1. SSSFD manipulator engineering using statistical experiment design techniques

    Science.gov (United States)

    Barnes, John

    1991-01-01

    The Satellite Servicer System Flight Demonstration (SSSFD) program is a series of Shuttle flights designed to verify major on-orbit satellite servicing capabilities, such as rendezvous and docking of free flyers, Orbital Replacement Unit (ORU) exchange, and fluid transfer. A major part of this system is the manipulator system that will perform the ORU exchange. The manipulator must possess adequate toolplate dexterity to maneuver a variety of EVA-type tools into position to interface with ORU fasteners, connectors, latches, and handles on the satellite, and to move workpieces and ORUs through 6 degree of freedom (dof) space from the Target Vehicle (TV) to the Support Module (SM) and back. Two cost efficient tools were combined to perform a study of robot manipulator design parameters. These tools are graphical computer simulations and Taguchi Design of Experiment methods. Using a graphics platform, an off-the-shelf robot simulation software package, and an experiment designed with Taguchi's approach, the sensitivities of various manipulator kinematic design parameters to performance characteristics are determined with minimal cost.

  2. Precipitation manipulation experiments – challenges and recommendations for the future

    DEFF Research Database (Denmark)

    Beier, Claus; Beierkuhnlein, Carl; Wohlgemuth, Thomas

    2012-01-01

    changes is therefore limited, as is their potential value for the development and testing of ecosystem models. This highlights the need for new precipitation experiments in biomes and ambient climatic conditions hitherto poorly studied applying relevant complex scenarios including changes in precipitation...

  3. Bats of the hardwood ecosystem experiment before timber harvest: assessment and prognosis

    Science.gov (United States)

    Jeremy J. Sheets; John O. Whitaker; Virgil Jr. Brack; Dale W. Sparks

    2013-01-01

    Before experimental harvest of the Yellowwood (YW) and Morgan-Monroe (MM) State Forests (Indiana) as part of the Hardwood Ecosystem Experiment, bats were sampled using mist nets at four locations in MM and five locations in YW during each summer 2006 through 2008. Netting locations were adjacent to forest stands scheduled for experimental manipulations following...

  4. Near real time/low latency data collection for climate warming manipulations and an elevated CO2 SPRUCE experiment

    Science.gov (United States)

    Krassovski, M.; Hanson, P. J.; Riggs, J. S.; Nettles, W. R., IV

    2017-12-01

    Climate change studies are one of the most important aspects of modern science and related experiments are getting bigger and more complex. One such experiment is the Spruce and Peatland Responses Under Climatic and Environmental Change experiment (SPRUCE, http://mnspruce.ornl.gov) conducted in in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF). The SPRUCE experimental mission is to assess ecosystem-level biological responses of vulnerable, high carbon terrestrial ecosystems to a range of climate warming manipulations and an elevated CO2 atmosphere. This manipulation experiment generates a lot of observational data and requires a reliable onsite data collection system, dependable methods to transfer data to a robust scientific facility, and real-time monitoring capabilities. This presentation shares our experience of establishing near real time/low latency data collection and monitoring system using satellite communication.

  5. Soil respiration is stimulated by elevated CO2 and reduced by summer drought: three years of measurements in a multifactor ecosystem manipulation experiment in a temperate heathland (CLIMAITE)

    DEFF Research Database (Denmark)

    Selsted, Merete Bang; van der Linden, Leon; Ibrom, Andreas

    2012-01-01

    This study investigated the impact of predicted future climatic and atmospheric conditions on soil respiration (RS) in a Danish Calluna‐Deschampsia‐heathland. A fully factorial in situ experiment with treatments of elevated atmospheric CO2 (+130 ppm), raised soil temperature (+0.4 °C) and extended...... summer drought (5–8% precipitation exclusion) was established in 2005. The average RS, observed in the control over 3 years of measurements (1.7 μmol CO2 m−2 sec−1), increased 38% under elevated CO2, irrespective of combination with the drought or temperature treatments. In contrast, extended summer...... due to reduced plant growth or changes in soil water holding capacity. An empirical model that predicts RS from soil temperature, soil moisture and plant biomass was developed and accounted for 55% of the observed variability in RS. The model predicted annual sums of RS in 2006 and 2007...

  6. Manipulators

    International Nuclear Information System (INIS)

    Andre, Y.; Routelous, F.; Spina, G.; Perpina, J.; Suquet, J.; Rossi, M.; Zanca, M.; Billiet, A.; Madec, L.; Lemoine, T.; Gaboriaud, G.; Aubert, B.; Rosenwald, J.C.; Neuenschwander, S.; Brisse, H.; Rehel, J.L.; Rebibo, G.; Bensimon, J.L.; Kulski, A.; Serhal, M.; Nguyen, K.V.; Lescure, R.; Cymbalista, M.

    2005-01-01

    Three articles have for purpose the radiation doses optimization in medical imaging. The first one concerns the radiation protection of manipulators working at a PET scan post, the second one concerns more particularly the optimization of doses delivered in pediatric computerized tomography, the third one is devoted to a comparison between radiation dose and image quality through scanners of adult temporal bone. (N.C.)

  7. Nutrient Budgets Calculated in Floodwaters Using a Whole-Ecosystem Experimental Manipulation

    Science.gov (United States)

    Talbot, C. J.; Paterson, M. J.; Xenopoulos, M. A.

    2017-12-01

    Flooding provides pathways for nutrients to move into surface waters and alter nutrient concentrations, therefore influencing downstream ecosystems and increasing events of eutrophication. Nutrient enrichment will likely affect water quality, primary production, and overall ecosystem function. Quantifying nutrient movement post-flood will help evaluate the risks or advantages that flooding will have on ecosystem processes. Here we constructed nutrient budgets using data collected as part of the Flooded Upland Dynamics Experiment (FLUDEX) at the Experimental Lakes Area (ELA) in northwestern Ontario. Three experimental reservoirs with varying amounts of stored carbon were created by flooding forested land from May through September annually from 1999 to 2003. Organic matter became a significant source of nutrients under flooded conditions and elevated reservoir total nitrogen (TN) and total phosphorus (TP) concentrations within one week of flooding. The highest TN (2.6 mg L-1) and TP (579 µg L-1) concentrations throughout the entire flooding experiment occurred in the medium carbon reservoir within the first two weeks of flooding in 1999. TN and TP fluxes were positive in all years of flooding. TP fluxes decreased after each flooding season therefore, TP production may be less problematic in floodplains subject to frequent repeated flooding. However, TN fluxes remained large even after repeated flooding. Therefore, flooding, whether naturally occurring or from anthropogenic flow alteration, may be responsible for producing significant amounts of nitrogen and phosphorus in aquatic ecosystems.

  8. Influence of soil erosion on CO2 exchange within the CarboZALF manipulation experiment

    Science.gov (United States)

    Hoffmann, Mathias; Augustin, Jürgen; Sommer, Michael

    2014-05-01

    Agriculture in the hummocky ground moraine landscape of NE-Germany is characterized by an increase in energy crop cultivation, like maize or sorghum. Both enhance lateral C fluxes by erosion and induce feedbacks on C dynamics of agroecosystems as a result of the time limited land cover and the vigorous crop growth. However, the actual impact of these phenomena on the CO2-sink/-source function of agricultural landscapes, is still not clear. Therefore we established the interdisciplinary project 'CarboZALF' in 2009. In our field experiment CarboZALF-D we are monitoring CO2 fluxes for soil-plant systems, which cover all landscape relevant soil states in respect to erosion and deposition, like Albic Cutanic Luvisol, Calcic Cutanic Luvisol, Calcaric Regosol and Endogleyic Colluvic Regosol. Furthermore, we induced erosion / deposition in a manipulation experiment. Automated chamber systems (2.5 m, basal area 1 m2, transparent) are placed at the manipulated sites as well as at one site neither influenced by erosion, nor by deposition. CO2 flux modelling of high temporal resolution includes ecosystem respiration (Reco), gross primary productivity (GPP) and net ecosystem exchange (NEE) based on parallel and continuous measurements of the CO2 exchange, soil and air temperatures as well as photosynthetic active radiation (PAR). Modelling includes gap filling which is needed in case of chamber malfunctions and abrupt disturbances by farming practice. In our presentation we would like to show results of the CO2 exchange measurements for one year. Differences are most pronounced between the non-eroded and the colluvial soil: The Endogleyic Colluvic Regosol showed higher flux rates for Reco and NEE compared to the Albic Cutanic Luvisol. The eroded soil (Calcic Cutanic Luvisol) demonstrated CO2fluxes intermediate between the non-affected and depositional site. Site-specific consequences for the soil C stocks will be also discussed in the presentation.

  9. Remote manipulator experience in target train maintenance at Fermilab

    International Nuclear Information System (INIS)

    Butala, S.W.

    1984-01-01

    When Fermilab was designed in the late 1960's and early 1970's, it was anticipated that Neutrino target train servicing could be costly in terms of personnel radiation exposure. This was based in part on the expectation that target intensities of at least 1E13 protons/pulse would be required to produce several neutrino interactions in a large bubble chamber detector. This was indeed later proven to be the case and historically the Neutrino beamline has been targeted with about one half of the protons available from the Main Ring. It was believed that much of the occupational radiation dose from the Neutrino Area could be spared by utilization of a remote manipulator system, which was eventually installed. It is the purpose of this report to examine the use of the Fermilab remote manipulator system and evaluate its cost effectiveness and success as an ALARA (As Low As Reasonably Achievable) tool. 16 references, 11 figures

  10. Voting Experiments: Measuring Vulnerability of Voting Procedures to Manipulation

    OpenAIRE

    Palguta, Jan

    2011-01-01

    A minimal reduction in strategic voter’s knowledge about other voters’ voting patterns severely limits her ability to strategically manipulate the voting outcome. In this paper I relax the implicit assumption made in the Gibbard-Satterthwaite’s impossibility theorem about strategic voter‘s complete information about all other voters’ preference profiles. Via a series of computation-based simulations I find that vulnerability to strategic voting is decreasing in the number of voters and increa...

  11. Short term response of a peatland to warming and drought - climate manipulation experiment in W Poland

    Science.gov (United States)

    Juszczak, Radosław; Chojnicki, Bogdan; Urbaniak, Marek; Leśny, Jacek; Silvennoinen, Hanna; Lamentowicz, Mariusz; Basińska, Anna; Gąbka, Maciej; Stróżecki, Marcin; Samson, Mateusz; Łuców, Dominika; Józefczyk, Damian; Hoffmann, Mathias; Olejnik, Janusz

    2016-04-01

    Central European peatlands are highly vulnerable as potential sources of carbon (C) to the atmosphere under anticipated climate changes, namely warming and drought (Fenner & Freeman 2011). We carried out a field manipulation experiment at Rzecin peatland in Poland to assess how those changes impact carbon balance, vegetation and water chemistry. The field site consists of three times replicated treatments (control, CO; simulated warming, W; prolonged drought, D and warming & drought, W+D). Temperature (T) was increased year around with infrared heaters (400W × 4 per site, approx. 60 Wṡm-2 addition of LW radiation, Kimball 2005) and precipitation was reduced with automatic curtain during growth seasons at night. The manipulation was successful yielding up to 0.4 oC and 1.0 oC T increases in air (30 cm height) and soil (5 cm depth), respectively, as well as a 35 % lower precipitation (in 2015). To study the C exchange we developed an automatic mobile platform for measuring CO2/CH4/H2O fluxes (LGR) as well as for 13CO2 and 13CH4 fluxes (PICARRO CRDS G2201-i) with dynamic ecosystem chambers (for NEE and Reco) and for simultaneous measurements of surface optical properties. Gap filling of the fluxes was done according to Hoffmann et al. 2015. In the very dry 2015, Rzecin peatland was a net source of CO2to the atmosphere (80 gCṡm-2yr-1). Warming and drought considerably diminished the source strength (7 gCṡm-2yr-1at the W+D site), due to lower cumulative respiration (Reco the smallest, 610 gC m-2yr-1, at W+D site). The highest CO2 emissions were measured from the site that was only warmed (W site, Reco 680 gCṡm-2yr-1), emphasizing the importance of drought in inhibiting respiration. Temperature increase also provoked the productivity (highest GPP at W site, -620 gCṡm-2yr-1), while drought yielded the lowest productivity (lowest GPP at D site, -550 gCṡm-2yr-1). Different vegetation parameters further support the C exchange estimates. Generally, warmer

  12. Soil Carbon Inputs and Ecosystem Respiration: a Field Priming Experiment in Arctic Coastal Tundra

    Science.gov (United States)

    Vaughn, L. S.; Zhu, B.; Bimueller, C.; Curtis, J. B.; Chafe, O.; Bill, M.; Abramoff, R. Z.; Torn, M. S.

    2016-12-01

    In Arctic ecosystems, climate change is expected to influence soil carbon stocks through changes in both plant carbon inputs and organic matter decomposition. This study addresses the potential for a priming effect, an interaction between these changes in which root-derived carbon inputs alter SOM decomposition rates via microbial biomass increases, co-metabolism of substrates, induced nitrogen limitation, or other possible mechanisms. The priming effect has been observed in numerous laboratory and greenhouse experiments, and is increasingly included in ecosystem models. Few studies, however, have evaluated the priming effect with in situ field manipulations. In a two-year field experiment in Barrow, Alaska, we tested for a priming effect under natural environmental variability. In September 2014 and August 2015, we added 6.1g of 13C-labeled glucose to 25cm diameter mesocosms, 15cm below the soil surface in the mineral soil layer. Over the following month, we quantified effects on the rate and temperature sensitivity of native (non-glucose) ecosystem respiration and GPP. Following the 2014 treatment, soil samples were collected at 1 and 3 weeks for microbial biomass carbon and 13C/12C analysis, and ion exchange membranes were buried for one week to assess nitrate and ammonium availability. In contrast with many laboratory incubation studies using soils from a broad range of ecosystems, we observed no significant priming effect. In spite of a clear signal of 13C-glucose decomposition in respired CO2 and microbial biomass, we detected no treatment effect on background ecosystem respiration or total microbial biomass carbon. Our findings suggest that glucose taken up by microbes was not used for production of additional SOM-decomposing enzymes, possibly due to stoichiometric limitations on enzyme production. To best inform models representing complex and dynamic ecosystems, this study calls for further research relating theory, laboratory findings, and field

  13. Tribal experiences and lessons learned in riparian ecosystem restoration

    Science.gov (United States)

    Ronald K. Miller; James E. Enote; Cameron L. Martinez

    1996-01-01

    Riparian ecosystems have been part of the culture of land use of native peoples in the Southwest United States for thousands of years. The experiences of tribal riparian initiatives to incorporate modern elements of environment and development with cultural needs are relatively few. This paper describes tribal case examples and approaches in riparian management which...

  14. A large-scale forest fragmentation experiment: the Stability of Altered Forest Ecosystems Project

    Science.gov (United States)

    Ewers, Robert M.; Didham, Raphael K.; Fahrig, Lenore; Ferraz, Gonçalo; Hector, Andy; Holt, Robert D.; Kapos, Valerie; Reynolds, Glen; Sinun, Waidi; Snaddon, Jake L.; Turner, Edgar C.

    2011-01-01

    Opportunities to conduct large-scale field experiments are rare, but provide a unique opportunity to reveal the complex processes that operate within natural ecosystems. Here, we review the design of existing, large-scale forest fragmentation experiments. Based on this review, we develop a design for the Stability of Altered Forest Ecosystems (SAFE) Project, a new forest fragmentation experiment to be located in the lowland tropical forests of Borneo (Sabah, Malaysia). The SAFE Project represents an advance on existing experiments in that it: (i) allows discrimination of the effects of landscape-level forest cover from patch-level processes; (ii) is designed to facilitate the unification of a wide range of data types on ecological patterns and processes that operate over a wide range of spatial scales; (iii) has greater replication than existing experiments; (iv) incorporates an experimental manipulation of riparian corridors; and (v) embeds the experimentally fragmented landscape within a wider gradient of land-use intensity than do existing projects. The SAFE Project represents an opportunity for ecologists across disciplines to participate in a large initiative designed to generate a broad understanding of the ecological impacts of tropical forest modification. PMID:22006969

  15. A large-scale forest fragmentation experiment: the Stability of Altered Forest Ecosystems Project.

    Science.gov (United States)

    Ewers, Robert M; Didham, Raphael K; Fahrig, Lenore; Ferraz, Gonçalo; Hector, Andy; Holt, Robert D; Kapos, Valerie; Reynolds, Glen; Sinun, Waidi; Snaddon, Jake L; Turner, Edgar C

    2011-11-27

    Opportunities to conduct large-scale field experiments are rare, but provide a unique opportunity to reveal the complex processes that operate within natural ecosystems. Here, we review the design of existing, large-scale forest fragmentation experiments. Based on this review, we develop a design for the Stability of Altered Forest Ecosystems (SAFE) Project, a new forest fragmentation experiment to be located in the lowland tropical forests of Borneo (Sabah, Malaysia). The SAFE Project represents an advance on existing experiments in that it: (i) allows discrimination of the effects of landscape-level forest cover from patch-level processes; (ii) is designed to facilitate the unification of a wide range of data types on ecological patterns and processes that operate over a wide range of spatial scales; (iii) has greater replication than existing experiments; (iv) incorporates an experimental manipulation of riparian corridors; and (v) embeds the experimentally fragmented landscape within a wider gradient of land-use intensity than do existing projects. The SAFE Project represents an opportunity for ecologists across disciplines to participate in a large initiative designed to generate a broad understanding of the ecological impacts of tropical forest modification.

  16. Long range manipulator development and experiments with dismantling tools

    International Nuclear Information System (INIS)

    Mueller, K.

    1993-01-01

    An existing handling system (EMIR) was used as a carrier system for various tools for concrete dismantling and radiation protection monitoring. It combined the advantages of long reach and high payload with highly dexterous kinematics. This system was enhanced mechanically to allow the use of different tools. Tool attachment devices for automatic tool exchange were investigated as well as interfaces (electric, hydraulic, compressed air, cooling water and signals). The control system was improved with regard to accuracy and sensor data processing. Programmable logic controller functions for tool control were incorporated. A free field mockup of the EMIR was build that allowed close simulation of dismantling scenarios without radioactive inventory. Aged concrete was provided for the integration tests. The development scheduled included the basic concept investigation; the development of tools and sensors; the EMIR hardware enhancement including a tool exchange; the adaption of tools and mockup and the final evaluation of the system during experiments

  17. The scene and the unseen: manipulating photographs for experiments on change blindness and scene memory: image manipulation for change blindness.

    Science.gov (United States)

    Ball, Felix; Elzemann, Anne; Busch, Niko A

    2014-09-01

    The change blindness paradigm, in which participants often fail to notice substantial changes in a scene, is a popular tool for studying scene perception, visual memory, and the link between awareness and attention. Some of the most striking and popular examples of change blindness have been demonstrated with digital photographs of natural scenes; in most studies, however, much simpler displays, such as abstract stimuli or "free-floating" objects, are typically used. Although simple displays have undeniable advantages, natural scenes remain a very useful and attractive stimulus for change blindness research. To assist researchers interested in using natural-scene stimuli in change blindness experiments, we provide here a step-by-step tutorial on how to produce changes in natural-scene images with a freely available image-processing tool (GIMP). We explain how changes in a scene can be made by deleting objects or relocating them within the scene or by changing the color of an object, in just a few simple steps. We also explain how the physical properties of such changes can be analyzed using GIMP and MATLAB (a high-level scientific programming tool). Finally, we present an experiment confirming that scenes manipulated according to our guidelines are effective in inducing change blindness and demonstrating the relationship between change blindness and the physical properties of the change and inter-individual differences in performance measures. We expect that this tutorial will be useful for researchers interested in studying the mechanisms of change blindness, attention, or visual memory using natural scenes.

  18. Warming Effects on Enzyme Activities are Predominant in Sub-surface Soils of an Arctic Tundra Ecosystem over 6-Year Field Manipulation

    Science.gov (United States)

    Kang, H.; Seo, J.; Kim, M.; Jung, J. Y.; Lee, Y. K.

    2017-12-01

    Arctic tundra ecosystems are of great importance because they store a large amount of carbon as un-decomposed organic matter. Global climate change is expected to affect enzyme activities and heterotrophic respiration in Arctic soils, which may accelerate greenhouse gas (GHG) emission through positive biological feedbacks. Unlike laboratory-based incubation experiments, field measurements often show different warming effects on decomposition of organic carbon and releases of GHGs. In the present study, we conducted a field-based warming experiment in Cambridge Bay, Canada (69°07'48″N, 105°03'36″W) by employing passive chambers during growing seasons over 6 years. A suite of enzyme activities (ß-glucosidase, cellobiohydrolase, N-acetylglucosaminidase, leucine aminopeptidase and phenol oxidase), microbial community structure (NGS), microbial abundances (gene copy numbers of bacteria and fungi), and soil chemical properties have been monitored in two depths (0-5 cm and 5-10 cm) of tundra soils, which were exposed to four different treatments (`control', `warming-only', `water-addition only', and both `warming and water-addition'). Phenol oxidase activity increased substantially, and bacterial community structure and abundance changed in the early stage (after 1 year's warming manipulation), but these changes disappeared afterwards. Most hydrolases were enhanced in surface soils by `water-addition only' over the period. However, the long-term effects of warming appeared in sub-surface soils where both `warming only' and `warming and water addition' increased hydrolase activities. Overall results of this study indicate that the warming effects on enzyme activities in surface soils are only short-term (phenol oxidase) or masked by water-limitation (hydrolases). However, hydrolases activities in sub-surface soils are more strongly enhanced than surface soils by warming, probably due to the lack of water limitation. Meanwhile, negative correlations between hydrolase

  19. Gender differences in emotion experience perception under different facial muscle manipulations.

    Science.gov (United States)

    Wang, Yufeng; Zhang, Dongjun; Zou, Feng; Li, Hao; Luo, Yanyan; Zhang, Meng; Liu, Yijun

    2016-04-01

    According to embodied emotion theory, facial manipulations should modulate and initiate particular emotions. However, whether there are gender differences in emotion experience perception under different facial muscle manipulations is not clear. Therefore, we conducted two behavioral experiments to examine gender differences in emotional perception in response to facial expressions (sad, neutral, and happy) under three conditions: (1) holding a pen using only the teeth (HPT), which facilitates the muscles typically associated with smiling; (2) holding a pen using only the lips (HPL), which inhibits the muscles typically associated with smiling; and (3) a control condition--hold no pen (HNP). We found that HPT made the emotional feelings more positive, and that the change degree of female's ratings of sad facial expressions between conditions (HPL to HPT) was larger than males'. These results suggested cognition can be affected by the interaction of the stimuli and the body, especially the female. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Combining short-term manipulative experiments with long-term palaeoecological investigations at high resolution to assess the response of Sphagnum peatlands to drought, fire and warming

    Directory of Open Access Journals (Sweden)

    M. Lamentowicz

    2016-09-01

    Full Text Available Northern hemisphere peatlands are substantial carbon stores. However, recent climate change and human impacts (e.g., drainage and atmospheric nutrient deposition may trigger the emission of their stored carbon to the atmosphere. Biodiversity losses are also an important consequence of those changes. Therefore, there is a need to recognise these processes in space and time. Global change experiments are often conducted to improve our understanding of the potential responses of various ecosystems to global warming and drought. Most of the experiments carried out in peatlands are focused on carbon balance and nitrogen deposition. Nevertheless, it is still unclear how fast peatlands respond to temperature changes and water-table lowering in the continental climate setting. This is important because continental regions account for a significant proportion of all northern hemisphere peatlands. A combination of short-term and long-term approaches in a single research project is especially helpful because it facilitates the correct interpretation of experimental data. Here we describe the CLIMPEAT project - a manipulative field experiment in a Sphagnum-dominated peatland supported by a high-resolution multi-proxy palaeoecological study. The design of the field experiment (e.g., treatments, methodology and biogeographical setting are presented. We suggest it is beneficial to support field experiments with an investigation of past environmental changes in the studied ecosystem, as human impacts during the past 300 years have already caused substantial changes in ecosystem functioning which may condition the response in experimental studies.

  1. The Hardwood Ecosystem Experiment: a framework for studying responses to forest management

    Science.gov (United States)

    Robert K. Swihart; Michael R. Saunders; Rebecca A. Kalb; G. Scott Haulton; Charles H., eds. Michler

    2013-01-01

    Conditions in forested ecosystems of southern Indiana are described before initiation of silvicultural treatments for the Hardwood Ecosystem Experiment (HEE). The HEE is a 100-year study begun in 2006 in Morgan-Monroe and Yellowwood State Forests to improve the sustainability of forest resources and quality of life of Indiana residents by understanding ecosystem and...

  2. A Large-Scale Multibody Manipulator Soft Sensor Model and Experiment Validation

    Directory of Open Access Journals (Sweden)

    Wu Ren

    2014-01-01

    Full Text Available Stress signal is difficult to obtain in the health monitoring of multibody manipulator. In order to solve this problem, a soft sensor method is presented. In the method, stress signal is considered as dominant variable and angle signal is regarded as auxiliary variable. By establishing the mathematical relationship between them, a soft sensor model is proposed. In the model, the stress information can be deduced by angle information which can be easily measured for such structures by experiments. Finally, test of ground and wall working conditions is done on a multibody manipulator test rig. The results show that the stress calculated by the proposed method is closed to the test one. Thus, the stress signal is easier to get than the traditional method. All of these prove that the model is correct and the method is feasible.

  3. A model ecosystem experiment and its computational simulation studies

    International Nuclear Information System (INIS)

    Doi, M.

    2002-01-01

    Simplified microbial model ecosystem and its computer simulation model are introduced as eco-toxicity test for the assessment of environmental responses from the effects of environmental impacts. To take the effects on the interactions between species and environment into account, one option is to select the keystone species on the basis of ecological knowledge, and to put it in the single-species toxicity test. Another option proposed is to put the eco-toxicity tests as experimental micro ecosystem study and a theoretical model ecosystem analysis. With these tests, the stressors which are more harmful to the ecosystems should be replace with less harmful ones on the basis of unified measures. Management of radioactive materials, chemicals, hyper-eutrophic, and other artificial disturbances of ecosystem should be discussed consistently from the unified view point of environmental protection. (N.C.)

  4. Hurricane Effects on a Shallow Lake Ecosystem and Its Response to a Controlled Manipulation of Water Level

    Directory of Open Access Journals (Sweden)

    Karl E. Havens

    2001-01-01

    Full Text Available In order to reverse the damage to aquatic plant communities caused by multiple years of high water levels in Lake Okeechobee, Florida (U.S., the Governing Board of the South Florida Water Management District (SFWMD authorized a "managed recession" to substantially lower the surface elevation of the lake in spring 2000. The operation was intended to achieve lower water levels for at least 8 weeks during the summer growing season, and was predicted to result in a large-scale recovery of submerged vascular plants. We treated this operation as a whole ecosystem experiment, and assessed ecological responses using data from an existing network of water quality and submerged plant monitoring sites. As a result of large-scale discharges of water from the lake, coupled with losses to evaporation and to water supply deliveries to agriculture and other regional users, the lake surface elevation receded by approximately 1 m between April and June. Water depths in shoreline areas that historically supported submerged plant communities declined from near 1.5 m to below 0.5 m. Low water levels persisted for the entire summer. Despite shallow depths, the initial response (in June 2000 of submerged plants was very limited and water remained highly turbid (due at first to abiotic seston and later to phytoplankton blooms. Turbidity decreased in July and the biomass of plants increased. However, submerged plant biomass did not exceed levels observed during summer 1999 (when water depths were greater until August. Furthermore, a vascular plant-dominated assemblage (Vallisnera, Potamogeton, and Hydrilla that occurred in 1999 was replaced with a community of nearly 98% Chara spp. (a macro-alga in 2000. Hence, the lake’s submerged plant community appeared to revert to an earlier successional stage despite what appeared to be better conditions for growth. To explain this unexpected response, we evaluated the impacts that Hurricane Irene may have had on the lake in the

  5. Hurricane effects on a shallow lake ecosystem and its response to a controlled manipulation of water level.

    Science.gov (United States)

    Havens, K E; Jin, K R; Rodusky, A J; Sharfstein, B; Brady, M A; East, T L; Iricanin, N; James, R T; Harwell, M C; Steinman, A D

    2001-04-04

    In order to reverse the damage to aquatic plant communities caused by multiple years of high water levels in Lake Okeechobee, Florida (U.S.), the Governing Board of the South Florida Water Management District (SFWMD) authorized a "managed recession" to substantially lower the surface elevation of the lake in spring 2000. The operation was intended to achieve lower water levels for at least 8 weeks during the summer growing season, and was predicted to result in a large-scale recovery of submerged vascular plants. We treated this operation as a whole ecosystem experiment, and assessed ecological responses using data from an existing network of water quality and submerged plant monitoring sites. As a result of large-scale discharges of water from the lake, coupled with losses to evaporation and to water supply deliveries to agriculture and other regional users, the lake surface elevation receded by approximately 1 m between April and June. Water depths in shoreline areas that historically supported submerged plant communities declined from near 1.5 m to below 0.5 m. Low water levels persisted for the entire summer. Despite shallow depths, the initial response (in June 2000) of submerged plants was very limited and water remained highly turbid (due at first to abiotic seston and later to phytoplankton blooms). Turbidity decreased in July and the biomass of plants increased. However, submerged plant biomass did not exceed levels observed during summer 1999 (when water depths were greater) until August. Furthermore, a vascular plant-dominated assemblage (Vallisneria, Potamogeton, and Hydrilla) that occurred in 1999 was replaced with a community of nearly 98% Chara spp. (a macro-alga) in 2000. Hence, the lake"s submerged plant community appeared to revert to an earlier successional stage despite what appeared to be better conditions for growth. To explain this unexpected response, we evaluated the impacts that Hurricane Irene may have had on the lake in the previous

  6. Ecosystem effects of thermal manipulation of a whole lake, Lake Breisjøen, southern Norway (THERMOS project)

    Science.gov (United States)

    Lydersen, E.; Aanes, K. J.; Andersen, S.; Andersen, T.; Brettum, P.; Baekken, T.; Lien, L.; Lindstræm, E. A.; Lævik, J. E.; Mjelde, M.; Oredalen, T. J.; Solheim, A. L.; Romstad, R.; Wright, R. F.

    2008-03-01

    We conducted a 3-year artificial deepening of the thermocline in the dimictic Lake Breisjøen, southern Norway, by means of a large submerged propeller. An adjacent lake served as untreated reference. The manipulation increased thermocline depth from 6 to 20 m, caused a significant increase in the heat content, and delayed ice-on by about 20 days. There were only minor changes in water chemistry. Concentrations of sulphate declined, perhaps due to greater reduction of sulphate at the sediment-water interface. Concentrations of particulate carbon and nitrogen decreased, perhaps due to increased sedimentation velocity. Water transparency increased. There was no significant change in concentration of phosphorus, the growth-limiting nutrient. There were few significant changes in principal biological components. Phytoplankton biomass and productivity did not change, although the chlorophyll-a concentration showed a small decrease. Phytoplankton species richness increased, and the species composition shifted. Growth of periphyton increased. There was no change in the macrophyte community. The manipulation did not affect the zooplankton biodiversity, but caused a significant shift in the relative abundance (measured as biomass) in the two major copepod species. The manipulation did not affect the individual density, but appeared to have changed the vertical distribution of zoobenthos. Fish populations were not affected. The lake is oligotrophic and clearwater and the manipulation did not change the supply of phosphorus, and thus there were only minor changes in lake chemistry and biology. Effects might be larger in eutrophic and dystrophic lakes in which internal processes are stronger.

  7. A comprehensive data acquisition and management system for an ecosystem-scale peatland warming and elevated CO2 experiment

    Science.gov (United States)

    Krassovski, M. B.; Riggs, J. S.; Hook, L. A.; Nettles, W. R.; Hanson, P. J.; Boden, T. A.

    2015-11-01

    Ecosystem-scale manipulation experiments represent large science investments that require well-designed data acquisition and management systems to provide reliable, accurate information to project participants and third party users. The SPRUCE project (Spruce and Peatland Responses Under Climatic and Environmental Change, http://mnspruce.ornl.gov) is such an experiment funded by the Department of Energy's (DOE), Office of Science, Terrestrial Ecosystem Science (TES) Program. The SPRUCE experimental mission is to assess ecosystem-level biological responses of vulnerable, high carbon terrestrial ecosystems to a range of climate warming manipulations and an elevated CO2 atmosphere. SPRUCE provides a platform for testing mechanisms controlling the vulnerability of organisms, biogeochemical processes, and ecosystems to climatic change (e.g., thresholds for organism decline or mortality, limitations to regeneration, biogeochemical limitations to productivity, and the cycling and release of CO2 and CH4 to the atmosphere). The SPRUCE experiment will generate a wide range of continuous and discrete measurements. To successfully manage SPRUCE data collection, achieve SPRUCE science objectives, and support broader climate change research, the research staff has designed a flexible data system using proven network technologies and software components. The primary SPRUCE data system components are the following: 1. data acquisition and control system - set of hardware and software to retrieve biological and engineering data from sensors, collect sensor status information, and distribute feedback to control components; 2. data collection system - set of hardware and software to deliver data to a central depository for storage and further processing; 3. data management plan - set of plans, policies, and practices to control consistency, protect data integrity, and deliver data. This publication presents our approach to meeting the challenges of designing and constructing an

  8. Measuring conditions and trends in ecosystem services at multiple scales: the Southern African Millennium Ecosystem Assessment (SAfMA) experience.

    Science.gov (United States)

    van Jaarsveld, A S; Biggs, R; Scholes, R J; Bohensky, E; Reyers, B; Lynam, T; Musvoto, C; Fabricius, C

    2005-02-28

    The Southern African Millennium Ecosystem Assessment (SAfMA) evaluated the relationships between ecosystem services and human well-being at multiple scales, ranging from local through to sub-continental. Trends in ecosystem services (fresh water, food, fuel-wood, cultural and biodiversity) over the period 1990-2000 were mixed across scales. Freshwater resources appear strained across the continent with large numbers of people not securing adequate supplies, especially of good quality water. This translates to high infant mortality patterns across the region. In some areas, the use of water resources for irrigated agriculture and urban-industrial expansion is taking place at considerable cost to the quality and quantity of freshwater available to ecosystems and for domestic use. Staple cereal production across the region has increased but was outstripped by population growth while protein malnutrition is on the rise. The much-anticipated wood-fuel crisis on the subcontinent has not materialized but some areas are experiencing shortages while numerous others remain vulnerable. Cultural benefits of biodiversity are considerable, though hard to quantify or track over time. Biodiversity resources remain at reasonable levels, but are declining faster than reflected in species extinction rates and appear highly sensitive to land-use decisions. The SAfMA sub-global assessment provided an opportunity to experiment with innovative ways to assess ecosystem services including the use of supply-demand surfaces, service sources and sink areas, priority areas for service provision, service 'hotspots' and trade-off assessments.

  9. Technical Report: Investigation of Carbon Cycle Processes within a Managed Landscape: An Ecosystem Manipulation and Isotope Tracer Approach

    Energy Technology Data Exchange (ETDEWEB)

    Griffis, Timothy J; Baker, John M; Billmark, Kaycie

    2009-06-01

    The goal of this research is to provide a better scientific understanding of carbon cycle processes within an agricultural landscape characteristic of the Upper Midwest. This project recognizes the need to study processes at multiple spatial and temporal scales to reduce uncertainty in ecosystem and landscape-scale carbon budgets to provide a sound basis for shaping future policy related to carbon management. Specifically, this project has attempted to answer the following questions: 1. Would the use of cover crops result in a shift from carbon neutral to significant carbon gain in corn-soybean rotation ecosystems of the Upper Midwest? 2. Can stable carbon isotope analyses be used to partition ecosystem respiration into its autotrophic and heterotrophic components? 3. Can this partitioning be used to better understand the fate of crop residues to project changes in the soil carbon reservoir? 4. Are agricultural ecosystems of the Upper Midwest carbon neutral, sinks, or sources? Can the proposed measurement and modeling framework help address landscape-scale carbon budget uncertainties and help guide future carbon management policy?

  10. Amazon forest ecosystem responses to elevated atmospheric CO2 and alterations in nutrient availability: filling the gaps with model-experiment integration

    Directory of Open Access Journals (Sweden)

    Florian eHofhansl

    2016-02-01

    Full Text Available The impacts of elevated CO2 (eCO2 and alterations in nutrient availability on the carbon (C storage capacity and resilience of the Amazon forest remain highly uncertain. Carbon dynamics are controlled by multiple eco-physiological processes responding to environmental change, but we lack solid experimental evidence, hampering theory development and thus representation in ecosystem models. Here, we present two ecosystem-scale manipulation experiments, to be carried out in the Amazon, that examine tropical ecosystem responses to eCO2 and nutrient addition and thus will elucidate the representation of crucial ecological processes by ecosystem models. We highlight current gaps in our understanding of tropical ecosystem responses to projected global changes in light of the eco-physiological assumptions considered by current ecosystem models. We conclude that a more detailed process-based representation of the spatial (e.g. soil type; plant functional type and temporal (seasonal and inter-annual variation diversity of tropical forests is needed to enhance model predictions of ecosystem responses to projected global environmental change.

  11. Jagiellonian University Advances in Ps Manipulations and Laser Studies in the AEgIS Experiment

    CERN Document Server

    Caravita, R; Amsler, C; Bonomi, G; Brusa, R S; Caccia, M; Castelli, F; Cerchiari, G; Comparat, D; Consolati, G; Demetrio, A; Di Noto, L; Doser, M; Evans, C; Ferragut, R; Fesel, J; Fontana, A; Gerber, S; Giammarchi, M; Gligorova, A; Guatieri, F; Haider, S; Hinterberger, A; Holmestad, H; Kellerbauer, A; Khalidova, O; Krasnický, D; Lagomarsino, V; Lansonneur, P; Lebrun, P; Malbrunot, C; Mariazzi, S; Marton, J; Matveev, V; Mazzotta, Z; Müller, S R; Nebbia, G; Nedelec, P; Oberthaler, M; Pacifico, N; Pagano, D; Penasa, L; Petracek, V; Prelz, F; Prevedelli, M; Ravelli, L; Rienäcker, B; Robert, J; Røhne, O M; Rotondi, A; Sandaker, H; Santoro, R; Smestad, L; Sorrentino, F; Testera, G; Tietje, I; Widmann, E; Yzombard, P; Zimmer, C; Zmeskal, J; Zurlo, N

    2017-01-01

    Positronium (Ps), the unstable bound state of electron and positron, is a valuable system for neutral antimatter spectroscopic studies and for antihydrogen production. Forming a pulsed beam cold antihydrogen using charge-exchange with the Rydberg Ps is the goal of the AEgIS Collaboration, which aims to measure gravity on neutral antimatter. Recent results achieved in producing, manipulating and studying Ps are summarized. Ps has been first produced with mesoporous silica targets in a reflection geometry. Spectroscopy of Ps n = 3 state has been conducted, yielding as a byproduct an independent estimate of the produced Ps temperature. Efficient laser excitation to the Rydberg levels was then achieved, validating the proof-of-concept of AEgIS. Subsequently, production of Ps from a new class of transmission targets was also achieved, opening the possibility for future experiments.

  12. Surgeon-Manipulated Live Surgery Video Recording Apparatuses: Personal Experience and Review of Literature.

    Science.gov (United States)

    Kapi, Emin

    2017-06-01

    Visual recording of surgical procedures is a method that is used quite frequently in practices of plastic surgery. While presentations containing photographs are quite common in education seminars and congresses, video-containing presentations find more favour. For this reason, the presentation of surgical procedures in the form of real-time video display has increased especially recently. Appropriate technical equipment for video recording is not available in most hospitals, so there is a need to set up external apparatus in the operating room. Among these apparatuses can be listed such options as head-mounted video cameras, chest-mounted cameras, and tripod-mountable cameras. The head-mounted video camera is an apparatus that is capable of capturing high-resolution and detailed close-up footage. The tripod-mountable camera enables video capturing from a fixed point. Certain user-specific modifications can be made to overcome some of these restrictions. Among these modifications, custom-made applications are one of the most effective solutions. The article makes an attempt to present the features and experiences concerning the use of a combination of a head- or chest-mounted action camera, a custom-made portable tripod apparatus of versatile features, and an underwater camera. The descriptions we used are quite easy-to-assembly, quickly installed, and inexpensive apparatuses that do not require specific technical knowledge and can be manipulated by the surgeon personally in all procedures. The author believes that video recording apparatuses will be integrated more to the operating room, become a standard practice, and become more enabling for self-manipulation by the surgeon in the near future. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  13. The single lineup paradigm: A new way to manipulate target presence in eyewitness identification experiments.

    Science.gov (United States)

    Oriet, Chris; Fitzgerald, Ryan J

    2018-02-01

    The suspect in eyewitness lineups may be guilty or innocent. These possibilities are traditionally simulated in eyewitness identification studies using a dual-lineup paradigm: All witnesses observe the same perpetrator and then receive one of two lineups. In this paradigm, the suspect's guilt is manipulated by including the perpetrator in one lineup and an innocent suspect in the other. The lineup is then filled with people matched to either the suspect (resulting in different fillers in perpetrator-present and perpetrator-absent lineups) or to the perpetrator (resulting in the same fillers in each lineup). An inescapable feature of the dual-lineup paradigm is that the perpetrator-present and perpetrator-absent lineups differ not only in the suspect's guilt, but also in their composition. Here, we describe a single-lineup paradigm: Subjects observe one of two perpetrators and then all subjects receive the same lineup containing one of the perpetrators. This alternative paradigm allows manipulation of the suspect's guilt without changing the lineup's composition. In three experiments, we applied the single-lineup paradigm to explore suspect-filler similarity and consistently found that increasing similarity reduced perpetrator identifications but did little to prevent innocent suspect misidentifications. Conversely, when fillers were matched to the perpetrator using a dual-lineup paradigm, increasing similarity reduced identification of perpetrators and innocent suspects. This finding suggests that the effect of filler similarity may depend on the person to whom the fillers are matched. We suggest that the single-lineup paradigm is a more ecologically valid and better controlled approach to creating suspect-matched lineups in laboratory investigations of eyewitness memory than existing procedures. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  14. Satyam’s Manipulative Accounting Methodology Unveiled: An Experience of an Asian Economy

    OpenAIRE

    MADAN LAL BHASIN

    2017-01-01

    Manipulative accounting practices are perennial and such practices have occurred in all eras, in all countries and affected millions of corporations. Unfortunately, there are few loopholes in accounting and auditing standards, which provide leeway and thus motivate accounting professionals to use aggressively manipulation practices. In fact, manipulative accounting (MA) involves the intentional cooking-up of financial records towards a pre-determined target. Every company indeed maneuvers the...

  15. Development of a mobile manipulator for nuclear plant disaster, HELIOS X. Mechanical design and basic experiments

    International Nuclear Information System (INIS)

    Noda, Satsuya; Hirose, Shigeo; Ueda, Koji; Nakano, Hisami; Horigome, Atsushi; Endo, Gen

    2016-01-01

    In places such as nuclear power plant disaster area, which it is difficult for human workers to enter, robots are required to scout those places instead of human workers. In this paper, we present a mobile manipulator HELIOS X for a nuclear plant decommissioning task. Firstly, we address demands and specifications for the robot, considering the mission of reconnaissance. Then we outline the system of the robot, mainly focusing on the following mechanism: 'Crank Wheel', 'Main Arm', 'Sphere Link Wrist', 'Camera Arm', 'Control System' and 'System architecture'. Especially, we installed 3 degree of freedom 'Camera Arm' on the 'Main Arm', in order to improve functionality of remote control system. This enables the operator to monitor both the gripper and its overall view of the robot. 'Camera Arm' helps the operator to recognize the distance from an object to the gripper, because the operator can interactively move the viewpoint of the camera, and monitor from another camera angle without changing the gripper's position. We confirmed the basic functionality of mobile base, 'Main Arm' and 'Camera Arm' through hardware experiments. We also demonstrated that HELIOS X could pass through the pull-to-open door with a substantial closing force when the operator watched camera view only. (author)

  16. Can current moisture responses predict soil CO2 efflux under altered precipitation regimes? A synthesis of manipulation experiments

    Science.gov (United States)

    As a key component of the carbon cycle, soil respiration (Rsoil) is being excessively studied with the aim of improving our understanding as well as our ability to predict Rsoil when climate changes. Many manipulation experiments have been performed to test how Rsoil and other carbon fluxes and ecos...

  17. How emotions affect logical reasoning: evidence from experiments with mood-manipulated participants, spider phobics, and people with exam anxiety

    OpenAIRE

    Jung, Nadine; Wranke, Christina; Hamburger, Kai; Knauff, Markus

    2014-01-01

    Recent experimental studies show that emotions can have a significant effect on the way we think, decide, and solve problems. This paper presents a series of four experiments on how emotions affect logical reasoning. In two experiments different groups of participants first had to pass a manipulated intelligence test. Their emotional state was altered by giving them feedback, that they performed excellent, poor or on average. Then they completed a set of logical inference problems (with if p,...

  18. A large-scale throughfall manipulation experiment on Walker Branch Watershed

    International Nuclear Information System (INIS)

    Turner, R.S.; Hanson, P.J.; Huston, M.A.; Garten, C.T. Jr.; Mulholland, P.J.

    1992-01-01

    A throughfall displacement experiment is being performed in a mixed-age upland-oak forest on the upper slopes of Walker Branch Watershed in eastern Tennessee to investigate the effects of decreased and increased rainfall on individual species and ecosystem processes at the spatial scale of forest stands. Approximately 25% of the throughfall on the ''dry'' plot will be collected in polyethylene troughs suspended above the forest floor and the water transferred by gravity through pipes across the control plot for distribution onto the ''wet'' plot. Each plot is approximately 0.6 ha in size. The 25% reduction in soil moisture anticipated for the dry plot is equivalent to the driest growing season of the 1980's drought, which was correlated with sapling mortality and reduced growth of yellow poplar on the watershed. The experimental treatments will last at least 5 years. A wide range of biological and chemical characteristics of forest stands win be investigated, including: forest growth and physiological responses of major tree and understory species, leaf area index, herbivory, litter fall, understory competition, litter decomposition, soil organic matter and microbial populations, nutrient availability, soil and soil solution chemistry, and biogeochemical cycling processes. Data on vegetation growth, mortality, and reproduction will be used in existing models of community structure to produce estimates of potential changes in species composition over longer time periods resulting from wet versus dry experimental scenarios

  19. Leveraging 35 years of Pinus taeda research in the southeastern US to constrain forest carbon cycle predictions: regional data assimilation using ecosystem experiments

    Science.gov (United States)

    Quinn Thomas, R.; Brooks, Evan B.; Jersild, Annika L.; Ward, Eric J.; Wynne, Randolph H.; Albaugh, Timothy J.; Dinon-Aldridge, Heather; Burkhart, Harold E.; Domec, Jean-Christophe; Fox, Thomas R.; Gonzalez-Benecke, Carlos A.; Martin, Timothy A.; Noormets, Asko; Sampson, David A.; Teskey, Robert O.

    2017-07-01

    Predicting how forest carbon cycling will change in response to climate change and management depends on the collective knowledge from measurements across environmental gradients, ecosystem manipulations of global change factors, and mathematical models. Formally integrating these sources of knowledge through data assimilation, or model-data fusion, allows the use of past observations to constrain model parameters and estimate prediction uncertainty. Data assimilation (DA) focused on the regional scale has the opportunity to integrate data from both environmental gradients and experimental studies to constrain model parameters. Here, we introduce a hierarchical Bayesian DA approach (Data Assimilation to Predict Productivity for Ecosystems and Regions, DAPPER) that uses observations of carbon stocks, carbon fluxes, water fluxes, and vegetation dynamics from loblolly pine plantation ecosystems across the southeastern US to constrain parameters in a modified version of the Physiological Principles Predicting Growth (3-PG) forest growth model. The observations included major experiments that manipulated atmospheric carbon dioxide (CO2) concentration, water, and nutrients, along with nonexperimental surveys that spanned environmental gradients across an 8.6 × 105 km2 region. We optimized regionally representative posterior distributions for model parameters, which dependably predicted data from plots withheld from the data assimilation. While the mean bias in predictions of nutrient fertilization experiments, irrigation experiments, and CO2 enrichment experiments was low, future work needs to focus modifications to model structures that decrease the bias in predictions of drought experiments. Predictions of how growth responded to elevated CO2 strongly depended on whether ecosystem experiments were assimilated and whether the assimilated field plots in the CO2 study were allowed to have different mortality parameters than the other field plots in the region. We present

  20. Leveraging 35 years of Pinus taeda research in the southeastern US to constrain forest carbon cycle predictions: regional data assimilation using ecosystem experiments

    Directory of Open Access Journals (Sweden)

    R. Q. Thomas

    2017-07-01

    Full Text Available Predicting how forest carbon cycling will change in response to climate change and management depends on the collective knowledge from measurements across environmental gradients, ecosystem manipulations of global change factors, and mathematical models. Formally integrating these sources of knowledge through data assimilation, or model–data fusion, allows the use of past observations to constrain model parameters and estimate prediction uncertainty. Data assimilation (DA focused on the regional scale has the opportunity to integrate data from both environmental gradients and experimental studies to constrain model parameters. Here, we introduce a hierarchical Bayesian DA approach (Data Assimilation to Predict Productivity for Ecosystems and Regions, DAPPER that uses observations of carbon stocks, carbon fluxes, water fluxes, and vegetation dynamics from loblolly pine plantation ecosystems across the southeastern US to constrain parameters in a modified version of the Physiological Principles Predicting Growth (3-PG forest growth model. The observations included major experiments that manipulated atmospheric carbon dioxide (CO2 concentration, water, and nutrients, along with nonexperimental surveys that spanned environmental gradients across an 8.6  ×  105 km2 region. We optimized regionally representative posterior distributions for model parameters, which dependably predicted data from plots withheld from the data assimilation. While the mean bias in predictions of nutrient fertilization experiments, irrigation experiments, and CO2 enrichment experiments was low, future work needs to focus modifications to model structures that decrease the bias in predictions of drought experiments. Predictions of how growth responded to elevated CO2 strongly depended on whether ecosystem experiments were assimilated and whether the assimilated field plots in the CO2 study were allowed to have different mortality parameters than the other field

  1. Nitrogen transformations in response to temperature and rainfall manipulation in oak savanna: A global change experiment

    Science.gov (United States)

    Wellman, R. L.; Boutton, T. W.; Tjoelker, M. G.; Volder, A.; Briske, D. D.

    2013-12-01

    Increasing concentrations of greenhouse gases are projected to elevate global surface air temperatures by 1.1 to 6.4°C by the end of the century, and potentially magnify the intensity and variability of seasonal precipitation distribution. The mid-latitude grasslands of North America are predicted to experience substantial modification in precipitation regimes, with a shift towards drier summers and wetter spring and fall seasons. Despite these predictions, little is known concerning the effects of these global climate change drivers or their potential interactive effects on nitrogen (N) cycling processes. The purpose of this study is to quantify seasonal variation in rates of N-mineralization, nitrification, and N-losses via leaching in soil subjected to experimental warming and rainfall manipulation. Research was conducted at the Texas A&M Warming and Rainfall Manipulation (WaRM) Site in College Station where eight 9x18m rainout shelters and two unsheltered controls were established in post oak savanna in 2003. Replicate annual rainfall redistribution treatments (n = 4) are applied at the shelter level (long term mean vs. 40% of summer redistributed to fall and spring with same annual total). Warming treatments (ambient vs. 24-hr IR canopy warming of 1-3°C) were applied to planted monocultures of juniper and little bluestem, and a juniper-grass combination. Both juniper and little bluestem are key species within the post oak savanna region. Plots were sampled from the full factorial design during years six and seven of the WaRM experiment. Soil N-mineralization, nitrification, and N-losses via leaching were assessed quarterly for two years using the resin core incubation method. Rainfall, species composition, and time interacted significantly to influence both ammonification and nitrification. Highest rates of ammonification (0.115 mg NH4+ -N/ kg soil/day) occurred in grass monocultures during summer in the control rainfall plots, whereas highest rates of

  2. Environmental influences on mate preferences as assessed by a scenario manipulation experiment.

    Science.gov (United States)

    Marzoli, Daniele; Moretto, Francesco; Monti, Aura; Tocci, Ornella; Roberts, S Craig; Tommasi, Luca

    2013-01-01

    Many evolutionary psychology studies have addressed the topic of mate preferences, focusing particularly on gender and cultural differences. However, the extent to which situational and environmental variables might affect mate preferences has been comparatively neglected. We tested 288 participants in order to investigate the perceived relative importance of six traits of an ideal partner (wealth, dominance, intelligence, height, kindness, attractiveness) under four different hypothetical scenarios (status quo/nowadays, violence/post-nuclear, poverty/resource exhaustion, prosperity/global well-being). An equal number of participants (36 women, 36 men) was allotted to each scenario; each was asked to allocate 120 points across the six traits according to their perceived value. Overall, intelligence was the trait to which participants assigned most importance, followed by kindness and attractiveness, and then by wealth, dominance and height. Men appraised attractiveness as more valuable than women. Scenario strongly influenced the relative importance attributed to traits, the main finding being that wealth and dominance were more valued in the poverty and post-nuclear scenarios, respectively, compared to the other scenarios. Scenario manipulation generally had similar effects in both sexes, but women appeared particularly prone to trade off other traits for dominance in the violence scenario, and men particularly prone to trade off other traits for wealth in the poverty scenario. Our results are in line with other correlational studies of situational variables and mate preferences, and represent strong evidence of a causal relationship of environmental factors on specific mate preferences, corroborating the notion of an evolved plasticity to current ecological conditions. A control experiment seems to suggest that our scenarios can be considered as realistic descriptions of the intended ecological conditions.

  3. Environmental influences on mate preferences as assessed by a scenario manipulation experiment.

    Directory of Open Access Journals (Sweden)

    Daniele Marzoli

    Full Text Available Many evolutionary psychology studies have addressed the topic of mate preferences, focusing particularly on gender and cultural differences. However, the extent to which situational and environmental variables might affect mate preferences has been comparatively neglected. We tested 288 participants in order to investigate the perceived relative importance of six traits of an ideal partner (wealth, dominance, intelligence, height, kindness, attractiveness under four different hypothetical scenarios (status quo/nowadays, violence/post-nuclear, poverty/resource exhaustion, prosperity/global well-being. An equal number of participants (36 women, 36 men was allotted to each scenario; each was asked to allocate 120 points across the six traits according to their perceived value. Overall, intelligence was the trait to which participants assigned most importance, followed by kindness and attractiveness, and then by wealth, dominance and height. Men appraised attractiveness as more valuable than women. Scenario strongly influenced the relative importance attributed to traits, the main finding being that wealth and dominance were more valued in the poverty and post-nuclear scenarios, respectively, compared to the other scenarios. Scenario manipulation generally had similar effects in both sexes, but women appeared particularly prone to trade off other traits for dominance in the violence scenario, and men particularly prone to trade off other traits for wealth in the poverty scenario. Our results are in line with other correlational studies of situational variables and mate preferences, and represent strong evidence of a causal relationship of environmental factors on specific mate preferences, corroborating the notion of an evolved plasticity to current ecological conditions. A control experiment seems to suggest that our scenarios can be considered as realistic descriptions of the intended ecological conditions.

  4. Effects on parathion on the ecology of a eutrophic aquatic ecosystem: limnocorral experiment

    International Nuclear Information System (INIS)

    Gasith, A.; Perry, A.S.; Mozel, Y.; Albright, J.L.

    1983-01-01

    Repetitive exposure of a eutrophic fish pond ecosystem, enclosed in limnocorrals, to 30 ppb parathion resulted in elimination of the potentially dominant zooplankton species, Moina micrura. Consequently, the populations of the rotifers Brachionus and Asplanchna markedly increased. Changes in the zooplankton composition and abundance were followed by increased fluctuations in phytoplankton biomass, phytoplankton photosynthesis, plankton respiration and community metabolism. Similar responses to parathion treatment were observed in previous studies under fish pond conditions. In the presence of fish the effect of parathion on the ecosystem was generally less pronounced and not uniform. The collapse of the zooplankton community and the rapid changes in limnological conditions in the control (untreated) limnocorrals severely limited the duration of the experiment. The results suggest that under eutrophic conditions, small enclosures may be useful for evaluation of the effect of toxicants on the ecosystem only in short term experiments with short lived chemicals. (author)

  5. Online Collaboration in Design Education: An Experiment in Real-Time Manipulation of Prototypes and Communication

    Science.gov (United States)

    Dreamson, Neal

    2017-01-01

    The features of collaboration in design education include effective and efficient communication and reflection, and feasible manipulation of design objects. For collaborative design, information and communication technology offers educators the possibility to change design pedagogy. However, there is a paucity of literature on relative advantages…

  6. The marketing and economic implications of the manipulation of share prices: Nigeria stock exchange experience

    Directory of Open Access Journals (Sweden)

    Ajayi Ezekiel Oluwole

    2012-12-01

    Full Text Available This paper examined the marketing and economic effects of the manipulation of share prices in the Nigerian Stock Exchange. The survey research design was adopted. Data collected was analyzed using the regression analysis. Student t- test was used to test the two hypotheses formulated at 0.05 level of significance. The findings of the study revealed that capital market infractions such as fraudulent disposal of investor assets, illegal fund management and the wonder bank syndrome, others are insider dealings, corporate accounting fraud and share price manipulations affects the capital market and the economy .The study concluded that share prices manipulation actually influences the marketing and economic values of the shares being manipulated. It was recommended that the Nigerian government must put in place strong regulatory measures and punish the entire offender that has been found guilty. It was also recommended that for the market to rebound, stockbrokers that accessed margin facility from banks should be provided with certain percentage of their contributions to the loan as cushion to help them move on with their business.

  7. Floral Sonication is an Innate Behaviour in Bumblebees that can be Fine-Tuned with Experience in Manipulating Flowers.

    Science.gov (United States)

    Morgan, Tan; Whitehorn, Penelope; Lye, Gillian C; Vallejo-Marín, Mario

    Bumblebees demonstrate an extensive capacity for learning complex motor skills to maximise exploitation of floral rewards. This ability is well studied in nectar collection but its role in pollen foraging is less well understood. Floral sonication is used by bees to extract pollen from some plant species with anthers which must be vibrated (buzzed) to release pollen. Pollen removal is determined by sonication characteristics including frequency and amplitude, and thus the ability to optimise sonication should allow bees to maximise the pollen collection. We investigated the ability of the buff-tailed bumblebee ( Bombus terrestris ) to modify the frequency and amplitude of their buzzes with increasing experience manipulating flowers of the buzz-pollinated plant Solanum rostratum . We analysed flight and feeding vibrations generated by naïve workers across feeding bouts. Feeding buzzes were of a higher frequency and a lower amplitude than flight buzzes. Both flight and feeding buzzes had reduced amplitudes with increasing number of foraging trips. However, the frequency of their feeding buzzes was reduced significantly more than their flight buzzes as bumblebee workers gained experience manipulating flowers. These results suggest that bumblebees are able to modify the characteristics of their buzzes with experience manipulating buzz-pollinated flowers. We discuss our findings in the context of bumblebee learning, and the current understanding of the optimal sonication characteristics for releasing pollen in buzz-pollinated species. Our results present a tantalising insight into the potential role of learning in floral sonication, paving the way for future research in this area.

  8. Snow depth manipulation experiments in a dry and a moist tundra

    Science.gov (United States)

    Kwon, M. J.; Czimczik, C. I.; Jung, J. Y.; Kim, M.; Lee, Y. K.; Nam, S.; Wagner, I.

    2017-12-01

    As a result of global warming, precipitation in the Arctic is expected to increase by 25-50% by the end of this century, mostly in the form of snow. However, precipitation patterns vary considerable in space and time, and future precipitation patterns are highly uncertain at local and regional scales. The amount of snowfall (or snow depth) influences a number of ecosystem properties in Arctic ecosystems, such as soil temperature over winter and soil moisture in the following growing season. These modifications then affect rates of carbon-related soil processes and photosynthesis, thus CO2 exchange rates between terrestrial ecosystems and the atmosphere. In this study, we investigate the effects of snow depth on the magnitude, sources and temporal dynamics of CO2 fluxes. We installed snow fences in a dry dwarf-shrub (Cambridge Bay, Canada; 69° N, 105° W) and a moist low-shrub (Council, Alaska, USA; 64° N, 165° W) tundra in summer 2017, and established control, and increased and reduced snow depth plots at each snow fence. Summertime CO2 flux rates (net ecosystem exchange, ecosystem respiration, gross primary production) and the fractions of autotrophic and heterotrophic respiration to ecosystem respiration were measured using manual chambers and radiocarbon signatures. Wintertime CO2 flux rates will be measured using soda lime adsorption technique and forced diffusion chambers. Soil temperature and moisture at multiple depths, as well as changes in soil properties and microbial communities will be also observed, to research whether these changes affect CO2 flux rates or patterns. Our study will elucidate how future snow depth and its impact on soil physical and biogeochemical properties influence the magnitude and sources of tundra-atmosphere CO2 exchange in the rapidly warming Arctic.

  9. A novel ice storm manipulation experiment in a northern hardwood forest

    Science.gov (United States)

    Lindsey E. Rustad; John L. Campbell

    2012-01-01

    Ice storms are an important natural disturbance within forest ecosystems of the northeastern United States. Current models suggest that the frequency and severity of ice storms may increase in the coming decades in response to changes in climate. Because of the stochastic nature of ice storms and difficulties in predicting their occurrence, most past investigations of...

  10. The marketing and economic implications of the manipulation of share prices: Nigeria stock exchange experience

    OpenAIRE

    Ajayi Ezekiel Oluwole; Omolekan Olushola Joshua

    2012-01-01

    This paper examined the marketing and economic effects of the manipulation of share prices in the Nigerian Stock Exchange. The survey research design was adopted. Data collected was analyzed using the regression analysis. Student t- test was used to test the two hypotheses formulated at 0.05 level of significance. The findings of the study revealed that capital market infractions such as fraudulent disposal of investor assets, illegal fund management and the wonder bank syndrome, others are i...

  11. Extended Model-Based Feedforward Compensation in L1 Adaptive Control for Mechanical Manipulators: Design and Experiments

    Directory of Open Access Journals (Sweden)

    Moussab eBennehar

    2015-12-01

    Full Text Available This paper deals with a new control scheme for Parallel Kinematic Manipulators (PKMs based on the L1 adaptive control theory. The original L1 adaptive controller is extended by including an adaptive loop based on the dynamics of the PKM. The additional model-based term is in charge of the compensation of the modeled nonlinear dynamics in the aim of improving the tracking performance. Moreover, the proposed controller is enhanced to reduce the internal forces, which may appear in the case of Redundantly Actuated PKMs (RA-PKMs. The generated control inputs are first regulated through a projection mechanism that reduces the antagonistic internal forces, before being applied to the manipulator. To validate the proposed controller and to show its effectiveness, real-time experiments are conducted on a new four degrees-of-freedom (4-DOFs RA-PKM developed in our laboratory.

  12. Satyam’s Manipulative Accounting Methodology Unveiled: An Experience of an Asian Economy

    Directory of Open Access Journals (Sweden)

    MADAN LAL BHASIN

    2017-01-01

    Full Text Available Manipulative accounting practices are perennial and such practices have occurred in all eras, in all countries and affected millions of corporations. Unfortunately, there are few loopholes in accounting and auditing standards, which provide leeway and thus motivate accounting professionals to use aggressively manipulation practices. In fact, manipulative accounting (MA involves the intentional cooking-up of financial records towards a pre-determined target. Every company indeed maneuvers the numbers, to a certain extent, as formally reported in its financial statements (FS to achieve budgetary targets and generously reward senior managers. From Enron, WorldCom to Satyam, it appeared that window-dressing leading to MA is a serious problem that is increasing both in its frequency and severity, which undermines the integrity of financial reports and eroded investors’ confidence. The responsibility of preventing, detecting and investigating financial frauds rests squarely on Board of Directors and they should adopt preventive steps. Despite the raft of CG, and financial disclosure reforms, corporate accounting still remains murky and companies continue to find ways to play ‘hide-and-seek’ game with the system. Satyam computers were once the crown jewel of Indian IT-industry but were brought to the ground by its founders in 2009 as a result of financial manipulations in FS. The present study provides a snapshot of how Mr. Raju (CEO and Chairman mastermind this maze of AM practices? Undoubtedly, Satyam scam is illegal and unethical in which computers were cleverly used to manipulate account books by creating fake invoices, inflating revenues, falsifying the cash and bank balances, showing non-existent interest on fixed deposits, showing ghost employees, and so on. Satyam fraud has shattered the dreams of investors, shocked the government and regulators and led to questioning of the accounting practices of auditors and CG norms in India. Finally

  13. Measuring conditions and trends in ecosystem services at multiple scales: the Southern African Millennium Ecosystem Assessment (SAfMA) experience

    OpenAIRE

    van Jaarsveld, A.S; Biggs, R; Scholes, R.J; Bohensky, E; Reyers, B; Lynam, T; Musvoto, C; Fabricius, C

    2005-01-01

    The Southern African Millennium Ecosystem Assessment (SAfMA) evaluated the relationships between ecosystem services and human well-being at multiple scales, ranging from local through to sub-continental. Trends in ecosystem services (fresh water, food, fuel-wood, cultural and biodiversity) over the period 1990-2000 were mixed across scales. Freshwater resources appear strained across the continent with large numbers of people not securing adequate supplies, especially of good quality water. T...

  14. Can current moisture responses predict soil CO2 efflux under altered precipitation regimes? A synthesis of manipulation experiments

    DEFF Research Database (Denmark)

    Vicca, S.; Bahn, M.; Estiarte, M.

    2014-01-01

    to fluctuations in soil temperature and soil water content can be used to predict SCE under altered rainfall patterns. Of the 58 experiments for which we gathered SCE data, 20 were discarded because either too few data were available or inconsistencies precluded their incorporation in the analyses. The 38...... remaining experiments were used to test the hypothesis that a model parameterized with data from the control plots (using soil temperature and water content as predictor variables) could adequately predict SCE measured in the manipulated treatment. Only for 7 of these 38 experiments was this hypothesis...... strongly on establishing response functions across a broader range of precipitation regimes and soil moisture conditions. Such experiments should make accurate measurements of water availability, should conduct high-frequency SCE measurements, and should consider both instantaneous responses...

  15. Making Sense with Manipulatives: Developing Mathematical Experiences for Early Childhood Teachers

    OpenAIRE

    Furman, Cara E.

    2017-01-01

    This paper is premised on the fact that math can be an important tool in helping people make sense of the world. Math offers a unique and particular lens, helping people to focus on a range of characteristics from shape and amount to the relationship between the general and the particular. To promote math as a tool for making sense, early childhood math instruction ought to teach it in a manner that helps children make sense of mathematical concepts. Specifically, I argue here that manipul...

  16. Meteorological and small scale internal ecosystem variability characterize the uncertainty of ecosystem level responses to elevated CO2. Insights from the Duke Forest FACE experiment

    Science.gov (United States)

    Paschalis, A.; Katul, G. G.; Fatichi, S.; Palmroth, S.; Way, D.

    2017-12-01

    One of the open questions in climate change research is the pathway by which elevated atmospheric CO2 concentration impacts the biogeochemical and hydrological cycles at the ecosystem scale. This impact leads to significant changes in long-term carbon stocks and the potential of ecosystems to sequester CO2, partially mitigating anthropogenic emissions. While the significance of elevated atmospheric CO2 concentration on instantaneous leaf-level processes such as photosynthesis and transpiration is rarely disputed, its integrated effect at the ecosystem level and at long-time scales remains a subject of debate. This debate has taken on some urgency as illustrated by differences arising between ecosystem modelling studies, and data-model comparisons using Free Air CO2 Enrichment (FACE) sites around the world. Inherent leaf-to-leaf variability in gas exchange rates can generate such inconsistencies. This inherent variability arises from the combined effect of meteorological "temporal" variability and the "spatial" variability of the biochemical parameters regulating vegetation carbon uptake. This combined variability leads to a non-straightforward scaling of ecosystem fluxes from the leaf to ecosystems. To illustrate this scaling behaviour, we used 10 years of leaf gas exchange measurements collected at the Duke Forest FACE experiment. The internal variability of the ecosystem parameters are first quantified and then combined with three different leaf-scale stomatal conductance models and an ecosystem model. The main results are: (a) Variability of the leaf level fluxes is dependent on both the meteorological drivers and differences in leaf age, position within the canopy, nitrogen and CO2 fertilization, which can be accommodated in model parameters; (b) Meteorological variability plays the dominant role at short temporal scales while parameter variability is significant at longer temporal scales. (c) Leaf level results do not necessarily translate to similar ecosystem

  17. Manipulating the magnetic anisotropy and magnetization dynamics by stress: Numerical calculation and experiment

    Science.gov (United States)

    Correa, M. A.; Bohn, F.

    2018-05-01

    We perform a theoretical and experimental investigation of the magnetic properties and magnetization dynamics of a ferromagnetic magnetostrictive multilayer grown onto a flexible substrate and submitted to external stress. We calculate the magnetic behavior and magnetoimpedance effect for a trilayered system from an approach that considers a magnetic permeability model for planar geometry and a magnetic free energy density which takes into account induced uniaxial and magnetoelastic anisotropy contributions. We verify remarkable modifications of the magnetic anisotropy with external stress, as well as we show that the dynamic magnetic response is strongly affected by these changes. We discuss the magnetic features that lead to modifications of the frequency limits where distinct mechanisms are responsible by the magnetoimpedance variations, enabling us to manipulate the resonance fields. To test the robustness of the approach, we directly compare theoretical results with experimental data. Thus, we provide experimental evidence to confirm the validity of the theoretical approach, as well as to manipulate the resonance fields to tune the MI response according to real applications in devices.

  18. Payments discourage coordination in ecosystem services provision: evidence from behavioral experiments in Southeast Asia

    Science.gov (United States)

    Bell, Andrew; Zhang, Wei

    2016-11-01

    The contribution of synthetic pesticides to closing yield gaps around the world is undeniable; however, their use is also a classic double-edged sword. Beyond the well-recognized social costs (e.g., pollution to soil and water, and health effects both on consumers and other species) there are also private costs on farmers beyond the direct costs of inputs, associated with elevated risks of both acute and chronic damage to farmers’ health, and with the destruction of populations of beneficial organisms. Managing agricultural land use to enhance natural pest control services (also called mobile agent-based ecosystem services or MABES) holds promise to reduce this growing reliance on pesticides, though it too carries costs. In particular, uncertainty in crop yield due to pest damages, as well as the need to coordinate pesticide use with neighboring farms, can be important obstacles to establishing the longer-term public good of natural pest regulation. Current thinking on promoting ecosystem services suggests that payments or other economic incentives are a good fit for the promotion of public good ecosystem services such as MABES. We undertook a framed field experiment to examine the role of subsidies for non-crop habitat in improving insect-based ecosystem services in two separate samples in Southeast Asia—Cambodia and Vietnam. Our central finding is that these two contexts are not poised equally to benefit from incentives promoting MABES, and in fact may be left worse off by payments schemes. As the study and practice of payments for ecosystem services programs grows, this finding provides an important qualifier on recent theory supporting the use of payments to promote public good ecosystem services—where the nature of the coordination problem is complex and nonlinear, farm systems can be made worse off by being encouraged to attempt it.

  19. Asymmetric responses of primary productivity to precipitation extremes: A synthesis of grassland precipitation manipulation experiments

    Czech Academy of Sciences Publication Activity Database

    Wilcox, K. R.; Shi, Z.; Gherardi, L. A.; Lemoine, N. P.; Koerner, S. E.; Hoover, D. L.; Bork, E.; Byrne, K. M.; Cahill, J.; Collins, S. L.; Evans, S.M.; Gilgen, Anna K.; Holub, Petr; Jiang, L.; Knapp, A. K.; LeCain, D.; Liang, J.; Garcia-Palacios, P.; Penuelas, J.; Pockman, W. T.; Smith, M. D.; Sun, S.; White, S. R.; Yahdjian, L.; Zhu, K.; Luo, Y.

    2017-01-01

    Roč. 23, č. 10 (2017), s. 4376-4385 ISSN 1354-1013 Institutional support: RVO:86652079 Keywords : net primary productivity * terrestrial ecosystems * temperate grassland * biomass allocation * plant-communities * tallgrass prairie * climate extremes * use efficiency * united-states * global-change * aboveground net primary productivity * belowground net primary productivity * biomass allocation * climate change * grasslands * meta-analysis * root biomass Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 8.502, year: 2016

  20. Community and ecosystem responses to elevational gradients

    DEFF Research Database (Denmark)

    Sundqvist, Maja K.; Sanders, Nate; Wardle, David A.

    2013-01-01

    Community structure and ecosystem processes often vary along elevational gradients. Their responses to elevation are commonly driven by changes in temperature, and many community- and ecosystem-level variables therefore frequently respond similarly to elevation across contrasting gradients...... elevational gradients for understanding community and ecosystem responses to global climate change at much larger spatial and temporal scales than is possible through conventional ecological experiments. However, future studies that integrate elevational gradient approaches with experimental manipulations...... will provide powerful information that can improve predictions of climate change impacts within and across ecosystems....

  1. The biotest basin of the Forsmark nuclear power plant, Sweden. An experiment on the ecosystem level

    International Nuclear Information System (INIS)

    Grimaas, U.

    1979-01-01

    Biotope models of various sizes and enclosed waters in connection with radionuclide release constitute important tools for radioecological experiments, representing an intermediate step between field and laboratory conditions. The biotest basin at Forsmark is especially constructed for investigations on the effects of radioactivity and heat on a brackish water ecosystem. The basin encloses a water area of 1km 2 in the outer archipelago of the region and is fed with cooling water and released radionuclides by a discharge tunnel. The quantities of the discharges into the basin are adjustable. The biotest experiment permits a quantification of the retention and transport of radionuclides at the various trophic levels. Of special value is the possibility to work with known populations of fish. The approach has the advantage of experimental ecology - the control of important parameters - under the impact of all environmental factors in a complete ecosystem. (author)

  2. Landscape experiences as a cultural ecosystem service in a Nordic context:

    DEFF Research Database (Denmark)

    Lindhjem, Henrik; Reinvang, Rasmus; Zandersen, Marianne

    2015-01-01

    Cultural ecosystem services in the form of experiences derived from landscapes are potentially important, but often overlooked. Given the large and unprecedented landscape changes many of the Nordic countries are undergoing, there is a need to find ways of including people’s preferences and the v......Cultural ecosystem services in the form of experiences derived from landscapes are potentially important, but often overlooked. Given the large and unprecedented landscape changes many of the Nordic countries are undergoing, there is a need to find ways of including people’s preferences...... and decision-making contexts in the Nordics. The literature demonstrates potentially high unaccounted welfare loss from landscape change. We find clear weaknesses in current practices, that a second phase will try to address. The project was carried out by Vista Analysis in Oslo and Department of Environmental...

  3. Soil acidification occurs under ambient conditions but is retarded by repeated drought: Results of a field-scale climate manipulation experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kopittke, G.R.; Tietema, A., E-mail: A.Tietema@uva.nl; Verstraten, J.M.

    2012-11-15

    Acid atmospheric emissions within Europe and North America have decreased strongly since 1985 and most recent acidification studies have focused on the changes occurring within ecosystems as a result of this decreased deposition. This current study documents a soil acidification trend under ambient N deposition conditions over a 13 year period, suggesting that acidification continues to be a process of concern at this Calluna vulgaris dominated heathland with an acidic sandy soil. The annual manipulation of climatic conditions on this heathland simulated the predicted summer rainfall reduction (drought) and resulted in a long term retardation of the soil acidification trend. The pH of the soil solution significantly decreased over the course of the trial for both treatments, however, in the final 2 years the decline continued only in the Control treatment. This retardation is primarily associated with the reduction in rainfall leading to lower drainage rates, reduced loss of cations and therefore reduced lowering of the soil acid neutralizing capacity (ANC). However, a change in the underlying mechanisms also indicated that N transformations became less important in the Drought treatment. This change corresponded to an increase in groundcover of an air-pollution tolerant moss species and it is hypothesized that this increasing moss cover filtered an increasing quantity of deposited N, thus reducing the N available for transformation. A soil acidification lag time is expected to increase between the two treatments due to the cumulative disparity in cation retention and rates of proton formation. To the authors' knowledge, this is the first study in which such acidification trends have been demonstrated in a field-scale climate manipulation experiment. -- Highlights: Black-Right-Pointing-Pointer A unique investigation of acidification on a field-scale climate manipulation trial. Black-Right-Pointing-Pointer Soil acidification occurred over 13 years of ambient N

  4. First mirror deposition/erosion experiment by using multi-purpose manipulators in KSTAR

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Suk-Ho, E-mail: sukhhong@nfri.re.kr [National Fusion Research Institute, Daejeon (Korea, Republic of); University of Science and Technology, Daejeon (Korea, Republic of); Department of Electrical Engineering, Hanyang University, Seoul (Korea, Republic of); Bang, Eunnam; Son, Soohyun [National Fusion Research Institute, Daejeon (Korea, Republic of); Kogut, Dmitry; Douai, David [CEA, IRFM, Association Euratom-CEA, Paul lez Durance (France)

    2016-11-01

    First mirrors are essential plasma-facing components (PFCs) for fusion devices. Erosion and redeposition on first mirrors are of interest, since they cause degradation of signal intensity. In order to trace deposition/erosion characteristics of amorphous hydrogenated carbon (a-C:H) films on first mirrors, two manipulators attached at midplane and divertor regions of KSTAR vacuum vessel are utilized. A net deposition rate of 0.3–0.5 nm/s during a discharge and an erosion rates of 0.1 nm/s during He ion cyclotron wall conditioning (ICWC) are obtained. Property of redeposited layers are different depending on the location, varying from soft polymer-like to hard diamond-like a-C:H layers. For the deposition and erosion of metal layers, a plan for a dedicated experimental session has been set at KSTAR.

  5. First mirror deposition/erosion experiment by using multi-purpose manipulators in KSTAR

    International Nuclear Information System (INIS)

    Hong, Suk-Ho; Bang, Eunnam; Son, Soohyun; Kogut, Dmitry; Douai, David

    2016-01-01

    First mirrors are essential plasma-facing components (PFCs) for fusion devices. Erosion and redeposition on first mirrors are of interest, since they cause degradation of signal intensity. In order to trace deposition/erosion characteristics of amorphous hydrogenated carbon (a-C:H) films on first mirrors, two manipulators attached at midplane and divertor regions of KSTAR vacuum vessel are utilized. A net deposition rate of 0.3–0.5 nm/s during a discharge and an erosion rates of 0.1 nm/s during He ion cyclotron wall conditioning (ICWC) are obtained. Property of redeposited layers are different depending on the location, varying from soft polymer-like to hard diamond-like a-C:H layers. For the deposition and erosion of metal layers, a plan for a dedicated experimental session has been set at KSTAR.

  6. Soil Nutrient Responses to Disturbance in a Northern Temperate Forest: The Influence of an Ice Storm Manipulation Experiment on Belowground Biogeochemical Cycling

    Science.gov (United States)

    Wiley, E.; King, C.; Richardson, A. D.; Landhäusser, S.

    2016-12-01

    Temperate forest ecosystems are increasingly impacted by human-induced changes in climate, which have the ability to alter the prevalence, severity, and extent of extreme weather events. Ice storms, an example of such extreme events, tend to be rarer and often occur as localized events, making them difficult to predict. As such, their impacts on ecosystem structure and functioning are poorly understood. We utilized a field manipulation experiment that effectively simulated natural ice storms of varying intensities to mechanistically understand the short-term nitrogen (N) responses to such extreme weather events. Net N mineralization and nitrification were quantified for both the organic and mineral soil horizons via 30-day in situ incubations of intact soil cores, while gross N transformations were measured in short-term laboratory incubations using the 15N pool dilution technique. Net C mineralization and N and C microbial biomass were also measured on disturbed soil cores via the chloroform fumigation incubation method. All microbial transformation measurements were carried out in the fall of the pre-treatment year (2015), and the spring and fall of the post-treatment years (2016 and 2017). We found that the availability of inorganic N to the microbial community did not significantly change immediately following the simulated ice storms. Over longer time-scales, however, we expect that N loss (mineralization, nitrification, denitrification) and conservation (immobilization) processes will be controlled more by the flow and availability of labile C from newly decaying fine and coarse woody debris that was dropped immediately following the ice storm. We hypothesize that the forested ecosystem is now in a state of N oligotrophy, and thus less likely to show any N response to disturbance in the short-term. This suggests that recovery of the forest over the long-term may be slower than that observed following a natural ice storm event that took place in 1998 in the

  7. On a problematic procedure to manipulate response biases in recognition experiments: the case of "implied" base rates.

    Science.gov (United States)

    Bröder, Arndt; Malejka, Simone

    2017-07-01

    The experimental manipulation of response biases in recognition-memory tests is an important means for testing recognition models and for estimating their parameters. The textbook manipulations for binary-response formats either vary the payoff scheme or the base rate of targets in the recognition test, with the latter being the more frequently applied procedure. However, some published studies reverted to implying different base rates by instruction rather than actually changing them. Aside from unnecessarily deceiving participants, this procedure may lead to cognitive conflicts that prompt response strategies unknown to the experimenter. To test our objection, implied base rates were compared to actual base rates in a recognition experiment followed by a post-experimental interview to assess participants' response strategies. The behavioural data show that recognition-memory performance was estimated to be lower in the implied base-rate condition. The interview data demonstrate that participants used various second-order response strategies that jeopardise the interpretability of the recognition data. We thus advice researchers against substituting actual base rates with implied base rates.

  8. Ecosystem Jenga!

    Science.gov (United States)

    Umphlett, Natalie; Brosius, Tierney; Laungani, Ramesh; Rousseau, Joe; Leslie-Pelecky, Diandra L.

    2009-01-01

    To give students a tangible model of an ecosystem and have them experience what could happen if a component of that ecosystem were removed; the authors developed a hands-on, inquiry-based activity that visually demonstrates the concept of a delicately balanced ecosystem through a modification of the popular game Jenga. This activity can be…

  9. Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment

    Science.gov (United States)

    M. Mazur; C.P.J. Mitchell; C.S. Eckley; S.L. Eggert; R.K. Kolka; S.D. Sebestyen; E.B. Swain

    2014-01-01

    Forest harvesting leads to changes in soil moisture, temperature and incident solar radiation, all strong environmental drivers of soil-air mercury (Hg) fluxes. Whether different forest harvesting practices significantly alter Hg fluxes from forest soils is unknown.We conducted a field-scale experiment in a northern Minnesota deciduous forest wherein gaseous Hg...

  10. Measuring conditions and trends in ecosystem services at multiple scales: the Southern African millennium ecosystem assessment (SAFMA) experience

    CSIR Research Space (South Africa)

    Van Jaarsveld, AS

    2005-01-01

    Full Text Available to ecosystems and for domestic use. Staple cereal production across the region has increased but was outstripped by population growth while protein malnutrition is on the rise. The much-anticipated wood-fuel crisis on the subcontinent has not materialized...

  11. Successive sheep grazing reduces population density of Brandt's voles in steppe grassland by altering food resources: a large manipulative experiment.

    Science.gov (United States)

    Li, Guoliang; Yin, Baofa; Wan, Xinrong; Wei, Wanhong; Wang, Guiming; Krebs, Charles J; Zhang, Zhibin

    2016-01-01

    Livestock grazing has shaped grassland ecosystems around the world. Previous studies indicated grazing showed various impacts on small rodents; however, most studies were conducted over 1-2 years without controlling for confounding factors such as immigration/emigration and predation in rodents. Brandt's voles (Lasiopodomys brandtii) are generally recognized as pests because of food overlap with domestic herbivores, but are also important for biodiversity conservation because they provide nests or food to many birds. Fully understanding the ecological relationship between domestic herbivores and small mammals is essential to making ecosystem management decisions. To address these needs, we carried out a field experiment during the period 2010-2013 to assess the effects of sheep grazing on vegetation and the population density of Brandt's voles along a gradient of three grazing intensities by using 12 large-scale enclosures. Responses of Brandt's voles to livestock grazing varied with grazing intensity and year. As compared to the control group, sheep grazing had no effect on vole abundance in the first year but an overall negative effect on vole abundance in the following 3 years. Successive grazing caused decreases in survival and male body mass of voles, but had no significant effect on fecundity. Negative effects of grazing were associated with a grazing-induced deterioration in both food quantity (reflected by biomass and cover of less-preferred plants), and food quality (measured by tannin and total phenol content). Our findings highlight the urgent need for more flexible management of yearly rotational grazing to optimize livestock production while maintaining species diversity and ecosystem health.

  12. How emotions affect logical reasoning: evidence from experiments with mood-manipulated participants, spider phobics, and people with exam anxiety.

    Science.gov (United States)

    Jung, Nadine; Wranke, Christina; Hamburger, Kai; Knauff, Markus

    2014-01-01

    Recent experimental studies show that emotions can have a significant effect on the way we think, decide, and solve problems. This paper presents a series of four experiments on how emotions affect logical reasoning. In two experiments different groups of participants first had to pass a manipulated intelligence test. Their emotional state was altered by giving them feedback, that they performed excellent, poor or on average. Then they completed a set of logical inference problems (with if p, then q statements) either in a Wason selection task paradigm or problems from the logical propositional calculus. Problem content also had either a positive, negative or neutral emotional value. Results showed a clear effect of emotions on reasoning performance. Participants in negative mood performed worse than participants in positive mood, but both groups were outperformed by the neutral mood reasoners. Problem content also had an effect on reasoning performance. In a second set of experiments, participants with exam or spider phobia solved logical problems with contents that were related to their anxiety disorder (spiders or exams). Spider phobic participants' performance was lowered by the spider-content, while exam anxious participants were not affected by the exam-related problem content. Overall, unlike some previous studies, no evidence was found that performance is improved when emotion and content are congruent. These results have consequences for cognitive reasoning research and also for cognitively oriented psychotherapy and the treatment of disorders like depression and anxiety.

  13. How emotions affect logical reasoning: evidence from experiments with mood-manipulated participants, spider phobics, and people with exam anxiety

    Science.gov (United States)

    Jung, Nadine; Wranke, Christina; Hamburger, Kai; Knauff, Markus

    2014-01-01

    Recent experimental studies show that emotions can have a significant effect on the way we think, decide, and solve problems. This paper presents a series of four experiments on how emotions affect logical reasoning. In two experiments different groups of participants first had to pass a manipulated intelligence test. Their emotional state was altered by giving them feedback, that they performed excellent, poor or on average. Then they completed a set of logical inference problems (with if p, then q statements) either in a Wason selection task paradigm or problems from the logical propositional calculus. Problem content also had either a positive, negative or neutral emotional value. Results showed a clear effect of emotions on reasoning performance. Participants in negative mood performed worse than participants in positive mood, but both groups were outperformed by the neutral mood reasoners. Problem content also had an effect on reasoning performance. In a second set of experiments, participants with exam or spider phobia solved logical problems with contents that were related to their anxiety disorder (spiders or exams). Spider phobic participants' performance was lowered by the spider-content, while exam anxious participants were not affected by the exam-related problem content. Overall, unlike some previous studies, no evidence was found that performance is improved when emotion and content are congruent. These results have consequences for cognitive reasoning research and also for cognitively oriented psychotherapy and the treatment of disorders like depression and anxiety. PMID:24959160

  14. Enhanced ergonomics approaches for product design: a user experience ecosystem perspective and case studies.

    Science.gov (United States)

    Xu, Wei

    2014-01-01

    This paper first discusses the major inefficiencies faced in current human factors and ergonomics (HFE) approaches: (1) delivering an optimal end-to-end user experience (UX) to users of a solution across its solution lifecycle stages; (2) strategically influencing the product business and technology capability roadmaps from a UX perspective and (3) proactively identifying new market opportunities and influencing the platform architecture capabilities on which the UX of end products relies. In response to these challenges, three case studies are presented to demonstrate how enhanced ergonomics design approaches have effectively addressed the challenges faced in current HFE approaches. Then, the enhanced ergonomics design approaches are conceptualised by a user-experience ecosystem (UXE) framework, from a UX ecosystem perspective. Finally, evidence supporting the UXE, the advantage and the formalised process for executing UXE and methodological considerations are discussed. Practitioner Summary: This paper presents enhanced ergonomics approaches to product design via three case studies to effectively address current HFE challenges by leveraging a systematic end-to-end UX approach, UX roadmaps and emerging UX associated with prioritised user needs and usages. Thus, HFE professionals can be more strategic, creative and influential.

  15. Gaseous mercury fluxes from forest soils in response to forest harvesting intensity: A field manipulation experiment

    International Nuclear Information System (INIS)

    Mazur, M.; Mitchell, C.P.J.; Eckley, C.S.; Eggert, S.L.; Kolka, R.K.; Sebestyen, S.D.; Swain, E.B.

    2014-01-01

    Forest harvesting leads to changes in soil moisture, temperature and incident solar radiation, all strong environmental drivers of soil–air mercury (Hg) fluxes. Whether different forest harvesting practices significantly alter Hg fluxes from forest soils is unknown. We conducted a field-scale experiment in a northern Minnesota deciduous forest wherein gaseous Hg emissions from the forest floor were monitored after two forest harvesting prescriptions, a traditional clear-cut and a clearcut followed by biomass harvest, and compared to an un-harvested reference plot. Gaseous Hg emissions were measured in quadruplicate at four different times between March and November 2012 using Teflon dynamic flux chambers. We also applied enriched Hg isotope tracers and separately monitored their emission in triplicate at the same times as ambient measurements. Clearcut followed by biomass harvesting increased ambient Hg emissions the most. While significant intra-site spatial variability was observed, Hg emissions from the biomass harvested plot (180 ± 170 ng m −2 d −1 ) were significantly greater than both the traditional clearcut plot (− 40 ± 60 ng m −2 d −1 ) and the un-harvested reference plot (− 180 ± 115 ng m −2 d −1 ) during July. This difference was likely a result of enhanced Hg 2+ photoreduction due to canopy removal and less shading from downed woody debris in the biomass harvested plot. Gaseous Hg emissions from more recently deposited Hg, as presumably representative of isotope tracer measurements, were not significantly influenced by harvesting. Most of the Hg tracer applied to the forest floor became sequestered within the ground vegetation and debris, leaf litter, and soil. We observed a dramatic lessening of tracer Hg emissions to near detection levels within 6 months. As post-clearcutting residues are increasingly used as a fuel or fiber resource, our observations suggest that gaseous Hg emissions from forest soils will increase, although it

  16. Aerodynamic control of NASP-type vehicles through vortex manipulation. Volume 3: Wing rock experiments

    Science.gov (United States)

    Suarez, Carlos J.; Smith, Brooke C.; Kramer, Brian R.; Ng, T. Terry; Ong, Lih-Yenn; Malcolm, Gerald N.

    1993-01-01

    Free-to-roll tests were conducted in water and wind tunnels in an effort to investigate the mechanisms of wing rock on a NASP-type vehicle. The configuration tested consisted of a highly-slender forebody and a 78 deg swept delta wing. In the water tunnel test, extensive flow visualization was performed and roll angle histories were obtained. In the wind tunnel test, the roll angle, forces and moments, and limited forebody and wing surface pressures were measured during the wing rock motion. A limit cycle oscillation was observed for angles of attack between 22 deg and 30 deg. In general, the experiments confirmed that the main flow phenomena responsible for the wing-body-tail wing rock are the interactions between the forebody and the wing vortices. The variation of roll acceleration (determined from the second derivative of the roll angle time history) with roll angle clearly slowed the energy balance necessary to sustain the limit cycle oscillation. Different means of suppressing wing rock by controlling the forebody vortices using small blowing jets were also explored. Steady blowing was found to be capable of suppressing wing rock, but significant vortex asymmetrices are created, causing the model to stop at a non-zero roll angle. On the other hand, alternating pulsed blowing on the left and right sides of the fore body was demonstrated to be a potentially effective means of suppressing wing rock and eliminating large asymmetric moments at high angles of attack.

  17. Terrestrial ecosystem responses to global change: A research strategy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    Uncertainty about the magnitude of global change effects on terrestrial ecosystems and consequent feedbacks to the atmosphere impedes sound policy planning at regional, national, and global scales. A strategy to reduce these uncertainties must include a substantial increase in funding for large-scale ecosystem experiments and a careful prioritization of research efforts. Prioritization criteria should be based on the magnitude of potential changes in environmental properties of concern to society, including productivity; biodiversity; the storage and cycling of carbon, water, and nutrients; and sensitivity of specific ecosystems to environmental change. A research strategy is proposed that builds on existing knowledge of ecosystem responses to global change by (1) expanding the spatial and temporal scale of experimental ecosystem manipulations to include processes known to occur at large scales and over long time periods; (2) quantifying poorly understood linkages among processes through the use of experiments that manipulate multiple interacting environmental factors over a broader range of relevant conditions than did past experiments; and (3) prioritizing ecosystems for major experimental manipulations on the basis of potential positive and negative impacts on ecosystem properties and processes of intrinsic and/or utilitarian value to humans and on feedbacks of terrestrial ecosystems to the atmosphere.

  18. Manipulators in teleoperation

    International Nuclear Information System (INIS)

    Hamel, W.R.

    1985-01-01

    Teleoperated manipulators represent a mature technology which has evolved over nearly 40 years of applications experience. The wide range of manipulator concepts developed thus far reflect differing applications, priorities, and philosophies. The technology of teleoperated manipulators is in a rapid state of change (just as are industrial robotics) fueled by microelectronics and materials advances. Large strides in performance and dexterity are now practical and advantageous. Even though improved controls and sensory feedback will increase functionality, overall costs should be reduced as manipulator fabrication and assembly labor costs are reduced through improved manufacturing technology. As these advances begin to materialize, broader applications in nonnuclear areas should occur

  19. Out-reach in-space technology experiments program: Control of flexible robot manipulators in zero gravity, experiment definition phase

    Science.gov (United States)

    Phillips, Warren F.

    1989-01-01

    The results obtained show that it is possible to control light-weight robots with flexible links in a manner that produces good response time and does not induce unacceptable link vibrations. However, deflections induced by gravity cause large static position errors with such a control system. For this reason, it is not possible to use this control system for controlling motion in the direction of gravity. The control system does, on the other hand, have potential for use in space. However, in-space experiments will be needed to verify its applicability to robots moving in three dimensions.

  20. Stated Choice Experiments with Complex Ecosystem Changes: The Effect of Information Formats on Estimated Variances and Choice Parameters

    OpenAIRE

    Hoehn, John P.; Lupi, Frank; Kaplowitz, Michael D.

    2010-01-01

    Stated choice experiments about ecosystem changes involve complex information. This study examines whether the format in which ecosystem information is presented to respondents affects stated choice outcomes. Our analysis develops a utility-maximizing model to describe respondent behavior. The model shows how alternative questionnaire formats alter respondents’ use of filtering heuristics and result in differences in preference estimates. Empirical results from a large-scale stated choice e...

  1. The impact of search engine selection and sorting criteria on vaccination beliefs and attitudes: two experiments manipulating Google output.

    Science.gov (United States)

    Allam, Ahmed; Schulz, Peter Johannes; Nakamoto, Kent

    2014-04-02

    During the past 2 decades, the Internet has evolved to become a necessity in our daily lives. The selection and sorting algorithms of search engines exert tremendous influence over the global spread of information and other communication processes. This study is concerned with demonstrating the influence of selection and sorting/ranking criteria operating in search engines on users' knowledge, beliefs, and attitudes of websites about vaccination. In particular, it is to compare the effects of search engines that deliver websites emphasizing on the pro side of vaccination with those focusing on the con side and with normal Google as a control group. We conducted 2 online experiments using manipulated search engines. A pilot study was to verify the existence of dangerous health literacy in connection with searching and using health information on the Internet by exploring the effect of 2 manipulated search engines that yielded either pro or con vaccination sites only, with a group receiving normal Google as control. A pre-post test design was used; participants were American marketing students enrolled in a study-abroad program in Lugano, Switzerland. The second experiment manipulated the search engine by applying different ratios of con versus pro vaccination webpages displayed in the search results. Participants were recruited from Amazon's Mechanical Turk platform where it was published as a human intelligence task (HIT). Both experiments showed knowledge highest in the group offered only pro vaccination sites (Z=-2.088, P=.03; Kruskal-Wallis H test [H₅]=11.30, P=.04). They acknowledged the importance/benefits (Z=-2.326, P=.02; H5=11.34, P=.04) and effectiveness (Z=-2.230, P=.03) of vaccination more, whereas groups offered antivaccination sites only showed increased concern about effects (Z=-2.582, P=.01; H₅=16.88, P=.005) and harmful health outcomes (Z=-2.200, P=.02) of vaccination. Normal Google users perceived information quality to be positive despite a

  2. Changes in Soil Organic Matter Abundance, Molecular Composition, and Diversity in an Arid Ecosystem in Response to Long-term Elevated CO2 Manipulation.

    Science.gov (United States)

    Hess, N. J.; Tfaily, M.; Evans, R. D.; Koyama, A.

    2017-12-01

    Little is known about how soils in arid ecosystems will respond to rising atmospheric CO2 concentration yet arid and semi-arid ecosystems cover more than 40% of Earth's land surface. Previous work in the Mojave Desert (Evans et al., 2014 Nature Climate Change) reported higher soil organic carbon (SOC) and total nitrogen (N) concentrations following 10 years exposure to elevated atmospheric CO2 at the Nevada Desert Free-Air-Carbon dioxide-Enrichment (FACE) Facility (NDFF). In this study, we investigated potential mechanisms that resulted in increased SOC and total N accumulation and stabilization using high resolution mass spectrometry at the NDFF site. Samples were collected from soil profiles to 1 m in depth with a 0.2 m a increment under the dominant evergreen shrub Larrea tridentata. The differences in the molecular composition and diversity of soil organic matter (SOM) were more evident in surface soils and declined with depth, and were consistent with higher SOC and total N concentrations under elevated than ambient CO2. Our molecular analysis also suggested increased root exudation and/or microbial necromass from stabilization of labile C and N contributed to SOM and N stocks. Increased microbial activity and metabolism under elevated CO2 compared to ambient plots suggested that elevated CO2 altered microbial carbon (C) use patterns, reflecting changes in the quality and quantity of SOC inputs. We found that plant-derived compounds were primary substrates for microbial activity under elevated CO2 and microbial products were the main constituents of stabilized SOM. Our results suggest that arid ecosystems are a potential large C sink under elevated CO2, give the extensive coverage of the land surface, and that labile compounds are transformed to stable SOM via microbial processes. Arid systems are limited by water, and thus may have a different C storage potential under changing climates than other ecosystems that are limited by nitrogen or phosphorus.

  3. The invasive shrub Prosopis juliflora enhances the malaria parasite transmission capacity of Anopheles mosquitoes: a habitat manipulation experiment.

    Science.gov (United States)

    Muller, Gunter C; Junnila, Amy; Traore, Mohamad M; Traore, Sekou F; Doumbia, Seydou; Sissoko, Fatoumata; Dembele, Seydou M; Schlein, Yosef; Arheart, Kristopher L; Revay, Edita E; Kravchenko, Vasiliy D; Witt, Arne; Beier, John C

    2017-07-05

    A neglected aspect of alien invasive plant species is their influence on mosquito vector ecology and malaria transmission. Invasive plants that are highly attractive to Anopheles mosquitoes provide them with sugar that is critical to their survival. The effect on Anopheles mosquito populations was examined through a habitat manipulation experiment that removed the flowering branches of highly attractive Prosopis juliflora from selected villages in Mali, West Africa. Nine villages in the Bandiagara district of Mali were selected, six with flowering Prosopis juliflora, and three without. CDC-UV light traps were used to monitor their Anopheles spp. vector populations, and recorded their species composition, population size, age structure, and sugar feeding status. After 8 days, all of the flowering branches were removed from three villages and trap catches were analysed again. Villages where flowering branches of the invasive shrub Prosopis juliflora were removed experienced a threefold drop in the older more dangerous Anopheles females. Population density dropped by 69.4% and the species composition shifted from being a mix of three species of the Anopheles gambiae complex to one dominated by Anopheles coluzzii. The proportion of sugar fed females dropped from 73 to 15% and males from 77 to 10%. This study demonstrates how an invasive plant shrub promotes the malaria parasite transmission capacity of African malaria vector mosquitoes. Proper management of invasive plants could potentially reduce mosquito populations and malaria transmission.

  4. Using an input manipulation experiment to partition greenhouse gas fluxes from a commercial Miscanthus plantation in the UK

    Science.gov (United States)

    Robertson, Andy; Davies, Christian; Smith, Pete; McNamara, Niall

    2014-05-01

    Miscanthus is a lignocellulosic C4 crop that can be grown for a number of practical end-uses but recently interest has increased in its viability as a bioenergy crop; both providing a renewable source of energy and helping to limit climate change by reducing carbon (C) emissions associated with energy generation. Recent studies have shown that Miscanthus plantations may increase stocks of soil organic carbon (SOC) however there is still considerable uncertainty surrounding estimates of net C exchange and the best management practices to achieve the best greenhouse gas (GHG) mitigation potential. Using an input manipulation experiment, we monitored emissions of N2O, CH4 and CO2 from living Miscanthus roots, aboveground plant litter and soil individually to quantify and partition these emissions and better understand the influence of abiotic factors on SOC and GHG dynamics under Miscanthus. In January 2009 twenty-five 2 m2 plots were set up in a three-year old 11 hectare commercial Miscanthus plantation in Lincolnshire, UK; with five replicates of five treatments. These treatments varied plant input (roots or senesced aboveground plant litter) to the soil by way of controlled exclusion techniques. The delta 13C value of soil C and CO2 emitted from each treatment was measured monthly between March 2009 and March 2013. Measurements of CH4 and N2O emissions were also taken at the soil surface from each treatment. Miscanthus-derived emissions were determined using the isotopic discrimination between C4 plant matter and C3 soil, and the treatments were compared to assess their effects on C inputs and outputs to the soil. Both CH4 and N2O emissions were below detection limits, mainly due to a lack of fertiliser additions and limited disturbance of the agricultural site. However, results for CO2 emissions indicate a strong seasonal variation; litter decomposition forms a large portion of the CO2 emissions in winter and spring whereas root respiration dominates the summer

  5. A manipulator

    International Nuclear Information System (INIS)

    Cole, G.V.; Hofmann, D.A.; Ashby, R.

    1984-01-01

    A manipulator is described, for remote handling of objects within an enclosure, by an operator outside the enclosure. The manipulator consists of a telescopically extensible arm member, the action of which is controlled by a motor-driven lead screw. (U.K.)

  6. Can current moisture responses predict soil CO2 efflux under altered precipitation regimes? A synthesis of manipulation experiments

    Science.gov (United States)

    S. Vicca; M. Bahn; M. Estiarte; E. E. van Loon; R. Vargas; G. Alberti; P. Ambus; M. A. Arain; C. Beier; L. P. Bentley; W. Borken; N. Buchmann; S. L. Collins; G. de Dato; J. S. Dukes; C. Escolar; P. Fay; G. Guidolotti; P. J. Hanson; A. Kahmen; G. Kröel-Dulay; T. Ladreiter-Knauss; K. S. Larsen; E. Lellei-Kovacs; E. Lebrija-Trejos; F. T. Maestre; S. Marhan; M. Marshall; P. Meir; Y. Miao; J. Muhr; P. A. Niklaus; R. Ogaya; J. Peñuelas; C. Poll; L. E. Rustad; K. Savage; A. Schindlbacher; I. K. Schmidt; A. R. Smith; E. D. Sotta; V. Suseela; A. Tietema; N. van Gestel; O. van Straaten; S. Wan; U. Weber; I. A. Janssens

    2014-01-01

    As a key component of the carbon cycle, soil CO2 efflux (SCE) is being increasingly studied to improve our mechanistic understanding of this important carbon flux. Predicting ecosystem responses to climate change often depends an extrapolation of current relationships between ecosystem processes and their climatic drivers to conditions not yet experienced by the...

  7. Running an open experiment: transparency and reproducibility in soil and ecosystem science

    Science.gov (United States)

    Bond-Lamberty, Ben; Peyton Smith, A.; Bailey, Vanessa

    2016-08-01

    Researchers in soil and ecosystem science, and almost every other field, are being pushed—by funders, journals, governments, and their peers—to increase transparency and reproducibility of their work. A key part of this effort is a move towards open data as a way to fight post-publication data loss, improve data and code quality, enable powerful meta- and cross-disciplinary analyses, and increase trust in, and the efficiency of, publicly-funded research. Many scientists however lack experience in, and may be unsure of the benefits of, making their data and fully-reproducible analyses publicly available. Here we describe a recent ‘open experiment’, in which we documented every aspect of a soil incubation online, making all raw data, scripts, diagnostics, final analyses, and manuscripts available in real time. We found that using tools such as version control, issue tracking, and open-source statistical software improved data integrity, accelerated our team’s communication and productivity, and ensured transparency. There are many avenues to improve scientific reproducibility and data availability, of which is this only one example, and it is not an approach suited for every experiment or situation. Nonetheless, we encourage the communities in our respective fields to consider its advantages, and to lead rather than follow with respect to scientific reproducibility, transparency, and data availability.

  8. Ecosystem partitioning of 15N-glycine after long-term climate and nutrient manipulations, plant clipping and addition of labile carbon in a subarctic heath tundra

    DEFF Research Database (Denmark)

    Sørensen, Pernille Lærkedal; Michelsen, Anders; Jonasson, Sven Evert

    2008-01-01

    of nitrogen (N). Here, we studied 15N label incorporation into microbes, plants and soil N pools after both long-term (12 years) climate manipulation and nutrient addition, plant clipping and a pulse-addition of labile C to the soil, in order to gain information on interactions among soil N and C pools...... addition. However, plants exerted control on the soil inorganic N concentrations and recovery of total dissolved 15N (TD15N), and likewise the microbes reduced these soil pools, but only when fed with labile C. Soil microbes in clipped plots were primarily C limited, and the findings of reduced N...... availability, both in the presence of plants and with the combined treatment of plant clipping and addition of sugar, suggest that the plant control of soil N pools was not solely due to plant uptake of soil N, but also partially caused by plants feeding labile C to the soil microbes, which enhanced...

  9. Terrestrial Ecosystem Responses to Global Change: A Research Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Ecosystems Working Group,

    1998-09-23

    Uncertainty about the magnitude of global change effects on terrestrial ecosystems and consequent feedbacks to the atmosphere impedes sound policy planning at regional, national, and global scales. A strategy to reduce these uncertainties must include a substantial increase in funding for large-scale ecosystem experiments and a careful prioritization of research efforts. Prioritization criteria should be based on the magnitude of potential changes in environmental properties of concern to society, including productivity; biodiversity; the storage and cycling of carbon, water, and nutrients; and sensitivity of specific ecosystems to environmental change. A research strategy is proposed that builds on existing knowledge of ecosystem responses to global change by (1) expanding the spatial and temporal scale of experimental ecosystem manipulations to include processes known to occur at large scales and over long time periods; (2) quantifying poorly understood linkages among processes through the use of experiments that manipulate multiple interacting environmental factors over a broader range of relevant conditions than did past experiments; and (3) prioritizing ecosystems for major experimental manipulations on the basis of potential positive and negative impacts on ecosystem properties and processes of intrinsic and/or utilitarian value to humans and on feedbacks of terrestrial ecosystems to the atmosphere. Models and experiments are equally important for developing process-level understanding into a predictive capability. To support both the development and testing of mechanistic ecosystem models, a two-tiered design of ecosystem experiments should be used. This design should include both (1) large-scale manipulative experiments for comprehensive testing of integrated ecosystem models and (2) multifactor, multilevel experiments for parameterization of process models across the critical range of interacting environmental factors (CO{sub 2}, temperature, water

  10. Spatial ecology and behavior of eastern box turtles on the hardwood ecosystem experiment: pre-treatment results

    Science.gov (United States)

    Andrea F. Currylow; Brian J. MacGowan; Rod N. Williams

    2013-01-01

    To understand better how eastern box turtles (Terrapene carolina carolina) are affected by forest management practices, we monitored movements of box turtles prior to silvicultural treatments within the Hardwood Ecosystem Experiment (HEE) in Indiana. During 2007 and 2008, we tracked 23-28 turtles on six units of the HEE. Estimated minimum convex...

  11. Temporal and Spatial Variation in Peatland Carbon Cycling and Implications for Interpreting Responses of an Ecosystem-Scale Warming Experiment

    Science.gov (United States)

    Natalie A. Griffiths; Paul J. Hanson; Daniel M. Ricciuto; Colleen M. Iversen; Anna M. Jensen; Avni Malhotra; Karis J. McFarlane; Richard J. Norby; Khachik Sargsyan; Stephen D. Sebestyen; Xiaoying Shi; Anthony P. Walker; Eric J. Ward; Jeffrey M. Warren; David J. Weston

    2017-01-01

    We are conducting a large-scale, long-term climate change response experiment in an ombrotrophic peat bog in Minnesota to evaluate the effects of warming and elevated CO2 on ecosystem processes using empirical and modeling approaches. To better frame future assessments of peatland responses to climate change, we characterized and compared spatial...

  12. Simulation of robot manipulators

    International Nuclear Information System (INIS)

    Kress, R.L.; Babcock, S.M.; Bills, K.C.; Kwon, D.S.; Schoenwald, D.A.

    1995-01-01

    This paper describes Oak Ridge National Laboratory's development of an environment for the simulation of robotic manipulators. Simulation includes the modeling of kinematics, dynamics, sensors, actuators, control systems, operators, and environments. Models will be used for manipulator design, proposal evaluation, control system design and analysis, graphical preview of proposed motions, safety system development, and training. Of particular interest is the development of models for robotic manipulators having at least one flexible link. As a first application, models have been developed for the Pacific Northwest Laboratories' Flexible Beam Testbed which is a one-Degree-Of-Freedom, flexible arm with a hydraulic base actuator. Initial results show good agreement between model and experiment

  13. An experiment framework to identify community functional components driving ecosystem processes and services delivery.

    NARCIS (Netherlands)

    Dias, A.; Berg, M.P.; de Bello, F.; van Oosten, A.R.; Bila, K.; Moretti, M.

    2013-01-01

    There is a growing consensus that the distribution of species trait values in a community can greatly determine ecosystem processes and services delivery. Two distinct components of community trait composition are hypothesized to chiefly affect ecosystem processes: (i) the average trait value of the

  14. Manipulating Strings in Python

    Directory of Open Access Journals (Sweden)

    William J. Turkel

    2012-07-01

    Full Text Available This lesson is a brief introduction to string manipulation techniques in Python. Knowing how to manipulate strings plays a crucial role in most text processing tasks. If you’d like to experiment with the following lessons, you can write and execute short programs as we’ve been doing, or you can open up a Python shell / Terminal to try them out on the command line.

  15. Introduction to the project DUNE, a DUst experiment in a low Nutrient, low chlorophyll Ecosystem

    Science.gov (United States)

    Guieu, C.; Dulac, F.; Ridame, C.; Pondaven, P.

    2013-07-01

    The main goal of the project DUNE was to estimate the impact of atmospheric deposition on an oligotrophic ecosystem based on mesocosm experiments simulating strong atmospheric inputs of Aeolian dust. Atmospheric deposition is now recognized as a significant source of macro- and micro-nutrients for the surface ocean, but the quantification of its role on the biological carbon pump is still poorly determined. We proposed in DUNE to investigate the role of atmospheric inputs on the functioning of an oligotrophic system particularly well adapted to this kind of study: the Mediterranean Sea. The Mediterranean Sea - etymologically, sea surrounded by land - is submitted to atmospheric inputs that are very variable both in frequency and intensity. During the thermal stratification period, only atmospheric deposition is prone to fertilize Mediterranean surface waters which has become very oligotrophic due to the nutrient depletion (after the spring bloom). This paper describes the objectives of DUNE and the implementation plan of a series of mesocosms experiments during which either wet or dry and a succession of two wet deposition fluxes of 10 g m-2 of Saharan dust have been simulated. After the presentation of the main biogeochemical initial conditions of the site at the time of each experiment, a general overview of the papers published in this special issue is presented, including laboratory results on the solubility of trace elements in erodible soils in addition to results from the mesocosm experiments. Our mesocosm experiments aimed at being representative of real atmospheric deposition events onto the surface of oligotrophic marine waters and were an original attempt to consider the vertical dimension in the study of the fate of atmospheric deposition within surface waters. Results obtained can be more easily extrapolated to quantify budgets and parameterize processes such as particle migration through a "captured water column". The strong simulated dust deposition

  16. A Long-term Forest Fertilization Experiment to Understand Ecosystem Responses to Atmospheric Nitrogen Deposition

    Science.gov (United States)

    Baron, J.; Advani, S. M.; Allen, J.; Boot, C.; Denef, K.; Denning, S.; Hall, E.; Moore, J. C.; Reuth, H.; Ryan, M. G.; Shaw, E.

    2016-12-01

    Long-term field experiments can reveal changes in ecosystem processes that may not be evident in short-term studies. Short-term measurements or experiments may have narrower objectives or unrealistic treatments in order to see a change, whereas long-term studies can reveal complex interactions that take longer to manifest. We report results from a long-term experiment (1996 to present) in subalpine forests to simulate the consequences of sustained atmospheric nitrogen (N) deposition. Loch Vale watershed in Rocky Mountain National Park, the location of the experiment, has received an order of magnitude greater atmospheric N deposition than estimated background since mid-20th Century. Augmenting that, in 1996 we began adding 25 kg NH4NO3 ha-1 yr-1 to three 30m x 30m old-growth Engelmann spruce and subalpine fir plots. Treated stands were matched by nearby controls. N addition caused rapid leaching of nitrate and cations from soils, and increased N mineralization and nitrification rates. These observations in the fertilized plots have been sustained over time. Soluble aluminum concentrations do not differ significantly between fertilized and control plots, but treated soils are now markedly more acidic (pH of 4.7) than original soil and controls (pH of 5.1); further acidification might increase aluminum leaching. Effects on soil carbon were complex, mediated by reductions in total microbial biomass, decreases in arbuscular mychorrizal and saprotropic fungi, and increased potential rates of N enzyme degrading activities. Initial soil C:N of 24 was lower than similar soils in low N deposition stands (C:N of 36). The C:N declined to 22 with treatment. Fertilized plots lost 11% soil C, but the mechanism is unclear. We did not measure changes in C inputs from litter, microbial biomass, or plant uptake, but there was no change in summer CO2 flux, measured in 2003, 2004, and 2014. Leaching of DOC from fertilized plots was elevated throughout the experiment, providing one

  17. Dynamics of a grassland ecosystem: botanical equilibrium in the Park Grass Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Silvertown, J

    1980-01-01

    The published results of the Park Grass Experiment (PGE), begun in 1856, provide up to 30 yr of annual data which may be used to determine whether the botanical composition of these grasslands was at equilibrium. Data covering a period exceeding 80 yr are available to test for relationships between hay yield (biomass), species diversity, species number and time. Species diversity and species number show negative relationships with plot biomass and with pH. These relationships were constant over time. The effects of biomass and pH on species number and species diversity were additive. Analysis of the flora of nine plots, each divided into grasses, legumes and a miscellaneous component showed that these components were at equilibrium. The effect of various endogenous factors on this botanical equilibrium was examined. No regular or irregular cycles of component biomass operating between years were detected and it is inferred that populations were regulated by processes operating within individual years. The biomasses of all three components were positively correlated within an unfertilized plot but the floristic components of plots receiving a fertilizer treatment showed few within-plot correlations. By contrast between-plot correlations of components were common for all plots with the exception of those receiving nitrogen fertilizer. The mechanisms of population regulation which maintained the park grass ecosystem at equilibrium are discussed and tests for these are proposed.

  18. Introduction to project DUNE, a DUst experiment in a low Nutrient, low chlorophyll Ecosystem

    Science.gov (United States)

    Guieu, C.; Dulac, F.; Ridame, C.; Pondaven, P.

    2014-01-01

    The main goal of project DUNE was to estimate the impact of atmospheric deposition on an oligotrophic ecosystem based on mesocosm experiments simulating strong atmospheric inputs of eolian mineral dust. Our mesocosm experiments aimed at being representative of real atmospheric deposition events onto the surface of oligotrophic marine waters and were an original attempt to consider the vertical dimension after atmospheric deposition at the sea surface. This introductory paper describes the objectives of DUNE and the implementation plan of a series of mesocosm experiments conducted in the Mediterranean Sea in 2008 and 2010 during which either wet or dry and a succession of two wet deposition fluxes of 10 g m-2 of Saharan dust have been simulated based on the production of dust analogs from erodible soils of a source region. After the presentation of the main biogeochemical initial conditions of the site at the time of each experiment, a general overview of the papers published in this special issue is presented. From laboratory results on the solubility of trace elements in dust to biogeochemical results from the mesocosm experiments and associated modeling, these papers describe how the strong simulated dust deposition events impacted the marine biogeochemistry. Those multidisciplinary results are bringing new insights into the role of atmospheric deposition on oligotrophic ecosystems and its impact on the carbon budget. The dissolved trace metals with crustal origin - Mn, Al and Fe - showed different behaviors as a function of time after the seeding. The increase in dissolved Mn and Al concentrations was attributed to dissolution processes. The observed decrease in dissolved Fe was due to scavenging on sinking dust particles and aggregates. When a second dust seeding followed, a dissolution of Fe from the dust particles was then observed due to the excess Fe binding ligand concentrations present at that time. Calcium nitrate and sulfate were formed in the dust

  19. Integration of Long term experiments on terrestrial ecosystem in AnaEE-France Research Infrastructure : concept and adding value

    Science.gov (United States)

    Chanzy, André; Chabbi, Abad; Houot, Sabine; Lafolie, François; Pichot, Christian; Raynal, Hélène; Saint-André, Laurent; Clobert, Jean; Greiveldinger, Lucile

    2015-04-01

    Continental ecosystems represent a critical zone that provide key ecological services to human populations like biomass production, that participate to the regulation of the global biogeochemical cycles and contribute and contribute to the maintenance of air and water quality. Global changes effects on continental ecosystems are likely to impact the fate of humanity, which is thus facing numerous challenges, such as an increasing demand for food and energy, competition for land and water use, or rapid climate warming. Hence, scientific progress in our understanding of the continental critical zone will come from studies that address how biotic and abiotic processes react to global changes. Long term experiments are required to take into account ecosystem inertia and feedback loops and to characterize trends and threshold in ecosystem dynamics. In France, 20 long-term experiments on terrestrial ecosystems are gathered within a single Research Infrastructure: ANAEE-France (http://www.anaee-s.fr), which is a part of AnaEE-Europe (http://www.anaee.com/). Each experiment consist in applying differentiated pressures on different plot over a long period (>20 years) representative of a range of management options. The originality of such infrastructure is a combination of experimental set up and long-term monitoring of simultaneous measurements of key ecosystem variables and parameters through a multi-disciplinary approach and replications of each treatment that improve the statistical strength of the results. The sites encompass gradients of climate conditions, ecosystem complexity and/or management, and can be used for calibration/validation of ecosystem functioning models as well as for the design of ecosystem management strategies. Gathering those experiments in a single research infrastructure is an important issue to enhance their visibility and increase the number of hosting scientific team by offering a range of services. These are: • Access to the ongoing long

  20. Quantifying the transient carbon dynamics of ecosystem scale carbon cycle responses to piñon pine mortality using a large-scale experimental manipulation, remote sensing and model-data fusion

    Science.gov (United States)

    Litvak, M. E.; Hilton, T. W.; Krofcheck, D. J.; Fox, A. M.; Robinson, E.; McDowell, N. G.; Rahn, T.; Sinsabaugh, R.

    2012-12-01

    The southwestern United States experienced an extended drought from 1999-2002 which led to widespread coniferous tree mortality throughout New Mexico, Arizona, Utah and Colorado. Piñon-juniper (PJ) woodlands, which occupy 24 million ha throughout the Southwest, proved to be extremely vulnerable to this drought, experiencing 40 to 95% mortality of piñon pine (Pinus edulis) and 2-25% mortality of juniper (Juniperus monosperma) in less than 3 years (Breshears et al., 2005). Understanding the response trajectories of these woodlands is crucial given that climate projections for the region suggest that episodic droughts, such as the one correlated with these recent conifer mortality, are likely to increase in frequency and severity and to expand northward. We are using a combination of eddy covariance, soil respiration, sap flow and biomass carbon pool measurements made at: (i) an undisturbed PJ woodland (control) in central New Mexico and at a manipulation site within 2 miles of the control where all piñon trees greater than 7 cm diameter at breast height within the 4 ha flux footprint were girdled (decreasing LAI by ~ 1/3) to quantify the response of ecosystem carbon and water dynamics in PJ woodlands to widespread piñon mortality. As expected, piñon mortality triggered an abrupt shift in carbon stocks from productive biomass to detritus, leading to a 25% decrease in gross primary production, and >50% decrease in net ecosystem production in the two years following mortality. Because litter and course woody debris are slow to decompose in these semiarid environments, ecosystem respiration initially decreased following mortality, and only increased two years post mortality following a large monsoon precipitation event. In the three years following mortality, reduced competition for water in these water limited ecosystems and increased light availability has triggered compensatory growth in understory vegetation observed in both remote sensing and ground

  1. Data-directed modelling of Daphnia dynamics in a long-term micro-ecosystem experiment

    NARCIS (Netherlands)

    Grasman, J.; Nes, van E.H.; Kersting, K.

    2009-01-01

    The micro-ecosystem under consideration consists of three compartments forming a closed chain in which water circulates. Three trophic levels are represented in different compartments: autotrophs (algae, mainly Chlorella vulgaris), herbivores (Daphnia magna) and microbial decomposers. From a 20

  2. Compliant Aerial Manipulators

    DEFF Research Database (Denmark)

    Bartelds, T.; Capra, A.; Hamaza, S.

    2016-01-01

    joints. The approach aims at limiting the influence of impacts on the controlled attitude dynamics in order to allow the aerial manipulator to remain stable during and after impact. The developed concept is intended to convert kinetic energy into potential energy, which is permanently stored into elastic...... elements by means of directional locking mechanisms. The proposed approach has been tested on a 2 d.o.f. manipulator mounted on a quadrotor UAV. The manipulation system has one active rotational d.o.f. compensating for pitch movements of the UAV and one passive linear joint which is in charge of absorbing...... the impact energy. The device has been used to validate the method through experiments, in comparison with a rigid manipulator. The results show that the proposed approach and the developed mechanical system achieve stable impact absorption without bouncing away from the interacting environment. Our work has...

  3. Nitrate removal in stream ecosystems measured by 15N addition experiments: Total uptake

    Science.gov (United States)

    Hall, R.O.; Tank, J.L.; Sobota, D.J.; Mulholland, P.J.; O'Brien, J. M.; Dodds, W.K.; Webster, J.R.; Valett, H.M.; Poole, G.C.; Peterson, B.J.; Meyer, J.L.; McDowell, W.H.; Johnson, S.L.; Hamilton, S.K.; Grimm, N. B.; Gregory, S.V.; Dahm, Clifford N.; Cooper, L.W.; Ashkenas, L.R.; Thomas, S.M.; Sheibley, R.W.; Potter, J.D.; Niederlehner, B.R.; Johnson, L.T.; Helton, A.M.; Crenshaw, C.M.; Burgin, A.J.; Bernot, M.J.; Beaulieu, J.J.; Arangob, C.P.

    2009-01-01

    We measured uptake length of 15NO-3 in 72 streams in eight regions across the United States and Puerto Rico to develop quantitative predictive models on controls of NO-3 uptake length. As part of the Lotic Intersite Nitrogen eXperiment II project, we chose nine streams in each region corresponding to natural (reference), suburban-urban, and agricultural land uses. Study streams spanned a range of human land use to maximize variation in NO-3 concentration, geomorphology, and metabolism. We tested a causal model predicting controls on NO-3 uptake length using structural equation modeling. The model included concomitant measurements of ecosystem metabolism, hydraulic parameters, and nitrogen concentration. We compared this structural equation model to multiple regression models which included additional biotic, catchment, and riparian variables. The structural equation model explained 79% of the variation in log uptake length (S Wtot). Uptake length increased with specific discharge (Q/w) and increasing NO-3 concentrations, showing a loss in removal efficiency in streams with high NO-3 concentration. Uptake lengths shortened with increasing gross primary production, suggesting autotrophic assimilation dominated NO-3 removal. The fraction of catchment area as agriculture and suburban-urban land use weakly predicted NO-3 uptake in bivariate regression, and did improve prediction in a set of multiple regression models. Adding land use to the structural equation model showed that land use indirectly affected NO-3 uptake lengths via directly increasing both gross primary production and NO-3 concentration. Gross primary production shortened SWtot, while increasing NO-3 lengthened SWtot resulting in no net effect of land use on NO- 3 removal. ?? 2009.

  4. Manipulatives Work!

    Science.gov (United States)

    Moch, Peggy L.

    2001-01-01

    Fifth graders (n=16) engaged in manipulative activities to improve their grasp of math concepts; one-third were identified as exceptional children. Posttest results after 12 lessons showed the overall class average increased from 49% to 59% and all areas improved compared to pretest scores. Attitude changes were also apparent. (Contains 24…

  5. Ecosystem experiment reveals benefits of natural and simulated beaver dams to a threatened population of steelhead (Oncorhynchus mykiss)

    Science.gov (United States)

    Bouwes, Nicolaas; Weber, Nicholas; Jordan, Chris E.; Saunders, W. Carl; Tattam, Ian A.; Volk, Carol; Wheaton, Joseph M.; Pollock, Michael M.

    2016-01-01

    Beaver have been referred to as ecosystem engineers because of the large impacts their dam building activities have on the landscape; however, the benefits they may provide to fluvial fish species has been debated. We conducted a watershed-scale experiment to test how increasing beaver dam and colony persistence in a highly degraded incised stream affects the freshwater production of steelhead (Oncorhynchus mykiss). Following the installation of beaver dam analogs (BDAs), we observed significant increases in the density, survival, and production of juvenile steelhead without impacting upstream and downstream migrations. The steelhead response occurred as the quantity and complexity of their habitat increased. This study is the first large-scale experiment to quantify the benefits of beavers and BDAs to a fish population and its habitat. Beaver mediated restoration may be a viable and efficient strategy to recover ecosystem function of previously incised streams and to increase the production of imperiled fish populations. PMID:27373190

  6. Mapping the ecosystem service delivery chain: Capacity, flow, and demand pertaining to aesthetic experiences in mountain landscapes.

    Science.gov (United States)

    Egarter Vigl, Lukas; Depellegrin, Daniel; Pereira, Paulo; de Groot, Rudolf; Tappeiner, Ulrike

    2017-01-01

    Accounting for the spatial connectivity between the provision of ecosystem services (ES) and their beneficiaries (supply-benefit chain) is fundamental to understanding ecosystem functioning and its management. However, the interrelationships of the specific chain links within ecosystems and the actual benefits that flow from natural landscapes to surrounding land have rarely been analyzed. We present a spatially explicit model for the analysis of one cultural ecosystem service (aesthetic experience), which integrates the complete ecosystem service delivery chain for Puez-Geisler Nature Park (Italy): (1) The potential service stock (ES capacity) relies on an expert-based land use ranking matrix, (2) the actual supply (ES flow) is based on visibility properties of observation points along recreational routes, (3) the beneficiaries of the service (ES demand) are derived from socioeconomic data as a measure of the visitation rate to the recreation location, and (4) the supply-demand relationship (ES budget) addresses the spatially explicit oversupply and undersupply of ES. The results indicate that potential ES stocks are substantially higher in core and buffer zones of protected areas than in surrounding land owing to the specific landscape composition. ES flow maps reveal service delivery to 80% of the total area studied, with the highest actual service supply to locations with long and open vistas. ES beneficiary analyses show the highest demand for aesthetic experiences in all-season tourist destinations like Val Badia and Val Gardena, where both recreational amenity and overnight stays are equally high. ES budget maps identify ES hot and cold spots in terms of ES delivery, and they highlight ES undersupply in nature protection buffer zones although they are characterized by highest ES capacity. We show how decision/policy makers can use the presented methodology to plan landscape protection measures and develop specific regulation strategies for visitors based on

  7. Fishing for ecosystem services.

    Science.gov (United States)

    Pope, Kevin L; Pegg, Mark A; Cole, Nicholas W; Siddons, Stephen F; Fedele, Alexis D; Harmon, Brian S; Ruskamp, Ryan L; Turner, Dylan R; Uerling, Caleb C

    2016-12-01

    Ecosystems are commonly exploited and manipulated to maximize certain human benefits. Such changes can degrade systems, leading to cascading negative effects that may be initially undetected, yet ultimately result in a reduction, or complete loss, of certain valuable ecosystem services. Ecosystem-based management is intended to maintain ecosystem quality and minimize the risk of irreversible change to natural assemblages of species and to ecosystem processes while obtaining and maintaining long-term socioeconomic benefits. We discuss policy decisions in fishery management related to commonly manipulated environments with a focus on influences to ecosystem services. By focusing on broader scales, managing for ecosystem services, and taking a more proactive approach, we expect sustainable, quality fisheries that are resilient to future disturbances. To that end, we contend that: (1) management always involves tradeoffs; (2) explicit management of fisheries for ecosystem services could facilitate a transition from reactive to proactive management; and (3) adaptive co-management is a process that could enhance management for ecosystem services. We propose adaptive co-management with an ecosystem service framework where actions are implemented within ecosystem boundaries, rather than political boundaries, through strong interjurisdictional relationships. Published by Elsevier Ltd.

  8. Experiences gained from implementing mandatory buffer strips in Denmark: how can we enhance their ecosystem services?

    Science.gov (United States)

    Kronvang, Brian; Hoffmann, Carl Christian; Baattrup-Pedersen, Annette; Hille, Sandra; Rubæk, Gitte; Heckrath, Goswin; Gertz, Flemming; Jensen, Henning; Feuerback, Peter; Strand, John; Stutter, Marc

    2015-04-01

    along watercourses from ca. 50,000 ha to ca. 25,000 ha and at the same time they reduced the width of the mandatory BSs from 10 m to 9 m. The aim of this presentation is to share the experience gained in Denmark on establishing mandatory BSs. Furthermore, we will show some preliminary results from two newly initiated research projects (BUFFERTECH and BALTICSEA2020) that studies how to enhance the ecosystem services provided by buffer strips. We will show how intelligently to guide managers when establishing BSs along watercourses at catchment scale utilizing a combined P-index model for soil erosion and a statistical model for P retention in BSs as well as results obtained from new 'Engineered' or 'Constructed' BSs that delays tile drainage flow from field to streams thereby increasing nutrient retention. Acknowledgement The work is supported by the Strategic Research Foundation/Innovation Fund Denmark project 'BUFFERTECH - Optimization of Ecosystem Services Provided by Buffer Strips Using Novel Technological Methods' (Grant No. 1305-00017B) and the BalticSea2020 project 'Integrerade skyddszoner (IBZ)'.

  9. Measuring conflicts in the management of anthropized ecosystems: Evidence from a choice experiment in a human-created Mediterranean wetland.

    Science.gov (United States)

    Perni, Ángel; Martínez-Paz, José Miguel

    2017-12-01

    Economic valuation of ecosystem services provides valuable information for the management of anthropized environments, where individual preferences can be heterogeneous and even opposed. Here, we discuss how these ecosystem services were approached in the literature and we address the main issues in relation to their economic valuation. We consider that avoiding misspecifications in economic valuation surveys requires considering the linkages between anthropized ecosystems and human intervention. To illustrate, we analyse the case study of a human-created Mediterranean wetland (El Hondo, SE Spain) using a Choice Experiment. Our findings suggest that management strategies in El Hondo should be oriented to improve the water ecological status, to enhance biodiversity and to develop ecotourism, whereas hunting should be strictly limited and controlled. Our measures of conflict (trade-off between ecosystem services and willingness to pay values) can help to find the optimal allocation of public and private goods and services and for the implementation of compensation schemes in the area. According to public preferences, a conservationist management strategy would generate 331,100 €/year in terms of environmental benefits, whereas a tourism-based management strategy would benefit society with 805,200 €/year. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Currency Manipulation

    OpenAIRE

    Weithing Zhang; Thomas Mertens; Tarek Hassan

    2014-01-01

    Many central banks manage the stochastic behavior of their currencies' exchange rates by imposing pegs relative to a target currency. We study the effects of such currency manipulation in a multi-country model of exchange rate determination with endogenous capital accumulation. We find that the imposition of an exchange rate peg relative to a given target currency increases the volatility of consumption in the target country and decreases the volatility of the target currency's exchange rate ...

  11. Hydraulic manipulator

    International Nuclear Information System (INIS)

    Sinha, A.K.; Srikrishnamurty, G.

    1990-01-01

    Successful operation of nuclear plant is largely dependent on safe handling of radio-active material. In order to reduce this handling problem and minimise the exposure of radiation, various handling equipment and manipulators have been developed according to the requirements. Manufacture of nuclear fuel, which is the most important part of the nuclear industry, involves handling of uranium ingots weighing approximately 250 kg. This paper describes a specially designed hydraulic manipulator for handling of the ingots in a limited space. It was designed to grab and handle the ingots in any position. This has following drive motions: (1)gripping and releasing, (2)lifting and lowering (z-motion), (3)rotation about the horizontal axis (azimuth drive), (4)rotation about the job axis, and (5)rotation about the vertical axis. For horizontal motion (X and Y axis motion) this equipment is mounted on a motorised trolley, so that it can move inside the workshop. For all drives except the rotation about the job axis, hydraulic cylinders have been used with a battery operated power pack. Trolley drive is also given power from same battery. This paper describes the design aspects of this manipulator. (author). 4 figs

  12. Soil life in reconstructed ecosystems: initial soil food web responses after rebuilding a forest soil profile for a climate change experiment

    Science.gov (United States)

    Paul T. Rygiewicz; Vicente J. Monleon; Elaine R. Ingham; Kendall J. Martin; Mark G. Johnson

    2010-01-01

    Disrupting ecosystem components, while transferring and reconstructing them for experiments can produce myriad responses. Establishing the extent of these biological responses as the system approaches a new equilibrium allows us more reliably to emulate comparable native systems. That is, the sensitivity of analyzing ecosystem processes in a reconstructed system is...

  13. Manipulating the Gradient

    Science.gov (United States)

    Gaze, Eric C.

    2005-01-01

    We introduce a cooperative learning, group lab for a Calculus III course to facilitate comprehension of the gradient vector and directional derivative concepts. The lab is a hands-on experience allowing students to manipulate a tangent plane and empirically measure the effect of partial derivatives on the direction of optimal ascent. (Contains 7…

  14. Model-experiment synthesis at two FACE sites in the southeastern US. Forest ecosystem responses to elevated CO[2]. (Invited)

    Science.gov (United States)

    Walker, A. P.; Zaehle, S.; De Kauwe, M. G.; Medlyn, B. E.; Dietze, M.; Hickler, T.; Iversen, C. M.; Jain, A. K.; Luo, Y.; McCarthy, H. R.; Parton, W. J.; Prentice, C.; Thornton, P. E.; Wang, S.; Wang, Y.; Warlind, D.; Warren, J.; Weng, E.; Hanson, P. J.; Oren, R.; Norby, R. J.

    2013-12-01

    Ecosystem observations from two long-term Free-Air CO[2] Enrichment (FACE) experiments (Duke forest and Oak Ridge forest) were used to evaluate the assumptions of 11 terrestrial ecosystem models and the consequences of those assumptions for the responses of ecosystem water, carbon (C) and nitrogen (N) fluxes to elevated CO[2] (eCO[2]). Nitrogen dynamics were the main constraint on simulated productivity responses to eCO[2]. At Oak Ridge some models reproduced the declining response of C and N fluxes, while at Duke none of the models were able to maintain the observed sustained responses. C and N cycles are coupled through a number of complex interactions, which causes uncertainty in model simulations in multiple ways. Nonetheless, the major difference between models and experiments was a larger than observed increase in N-use efficiency and lower than observed response of N uptake. The results indicate that at Duke there were mechanisms by which trees accessed additional N in response to eCO[2] that were not represented in the ecosystem models, and which did not operate with the same efficiency at Oak Ridge. Sequestration of the additional productivity under eCO[2] into forest biomass depended largely on C allocation. Allocation assumptions were classified into three main categories--fixed partitioning coefficients, functional relationships and a partial (leaf allocation only) optimisation. The assumption which best constrained model results was a functional relationship between leaf area and sapwood area (pipe-model) and increased root allocation when nitrogen or water were limiting. Both, productivity and allocation responses to eCO[2] determined the ecosystem-level response of LAI, which together with the response of stomatal conductance (and hence water-use efficiency; WUE) determined the ecosystem response of transpiration. Differences in the WUE response across models were related to the representation of the relationship of stomatal conductance to CO[2] and

  15. Uncovering stability mechanisms in microbial ecosystems - combining microcosm experiments, computational modelling and ecological theory in a multidisciplinary approach

    Science.gov (United States)

    Worrich, Anja; König, Sara; Banitz, Thomas; Centler, Florian; Frank, Karin; Kästner, Matthias; Miltner, Anja; Thullner, Martin; Wick, Lukas

    2015-04-01

    Although bacterial degraders in soil are commonly exposed to fluctuating environmental conditions, the functional performance of the biodegradation processes can often be maintained by resistance and resilience mechanisms. However, there is still a gap in the mechanistic understanding of key factors contributing to the stability of such an ecosystem service. Therefore we developed an integrated approach combining microcosm experiments, simulation models and ecological theory to directly make use of the strengths of these disciplines. In a continuous interplay process, data, hypotheses, and central questions are exchanged between disciplines to initiate new experiments and models to ultimately identify buffer mechanisms and factors providing functional stability. We focus on drying and rewetting-cycles in soil ecosystems, which are a major abiotic driver for bacterial activity. Functional recovery of the system was found to depend on different spatial processes in the computational model. In particular, bacterial motility is a prerequisite for biodegradation if either bacteria or substrate are heterogeneously distributed. Hence, laboratory experiments focussing on bacterial dispersal processes were conducted and confirmed this finding also for functional resistance. Obtained results will be incorporated into the model in the next step. Overall, the combination of computational modelling and laboratory experiments identified spatial processes as the main driving force for functional stability in the considered system, and has proved a powerful methodological approach.

  16. Combined effects of local habitat, anthropogenic stress, and dispersal on stream ecosystems: a mesocosm experiment.

    Science.gov (United States)

    Turunen, Jarno; Louhi, Pauliina; Mykrä, Heikki; Aroviita, Jukka; Putkonen, Emmi; Huusko, Ari; Muotka, Timo

    2018-06-06

    The effects of anthropogenic stressors on community structure and ecosystem functioning can be strongly influenced by local habitat structure and dispersal from source communities. Catchment land uses increase the input of fine sediments into stream channels, clogging the interstitial spaces of benthic habitats. Aquatic macrophytes enhance habitat heterogeneity and mediate important ecosystem functions, being thus a key component of habitat structure in many streams. Therefore, the recovery of macrophytes following in-stream habitat modification may be prerequisite for successful stream restoration. Restoration success is also affected by dispersal of organisms from the source community, with potentially strongest responses in relatively isolated headwater sites that receive limited amount of dispersing individuals. We used a factorial design in a set of stream mesocosms to study the independent and combined effects of an anthropogenic stressor (sand sedimentation), local habitat (macrophytes, i.e. moss transplants) and enhanced dispersal (two levels: high vs. low) on organic matter retention, algal accrual rate, leaf decomposition and macroinvertebrate community structure. Overall, all responses were simple additive effects with no interactions between treatments. Sand reduced algal accumulation, total invertebrate density and density of a few individual taxa. Mosses reduced algal accrual rate and algae-grazing invertebrates, but enhanced organic matter retention and detritus- and filter-feeders. Mosses also reduced macroinvertebrate diversity by increasing the dominance by a few taxa. Mosses also reduced leaf-mass loss, possibly because the organic matter retained by mosses provided an additional food source for leaf-shredding invertebrates and thus reduced shredder aggregation into leaf packs. The effect of mosses on macroinvertebrate communities and ecosystem functioning was distinct irrespective of the level of dispersal, suggesting strong environmental

  17. Hydraulic manipulator research at ORNL

    International Nuclear Information System (INIS)

    Kress, R.L.; Jansen, J.F.; Love, L.J.

    1997-01-01

    Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL's flexible/prismatic test stand

  18. Hydraulic manipulator research at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States); Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States)

    1997-03-01

    Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL`s flexible/prismatic test stand.

  19. Evaluation of seasonal changes in methane flux in a wetland ecosystem using the Closed Geosphere Experiment Facility

    Science.gov (United States)

    Suzuki, S.; Inubushi, K.; Yokozawa, M.; Hara, T.; Nishidate, K.; Tsuga, S.; Tako, Y.; Nakamura, Y.

    2009-04-01

    To estimate CH4 emission from a wetland ecosystem to the atmosphere, seasonal change in CH4 flux was measured continuously in the Closed Geosphere Experiment Facility (CGEF). Plant-mediated transport is one of the important pathways for CH4 emission from Phragmites australis-dominated vegetation because most CH4 emission occurs through P. australis plant. The CGEF is equipped with a Geosphere Module (GM) and a Geosphere Material Circulation (GMC) system. The size of the GM is 5.8 m Ã- 8.7 m in ground area with an average height of 11.9 m, including the soil depth of 3.1 m. A wetland ecosystem dominated by P. australis was introduced into the GM. The CGEF can control air temperature and CO2 concentration in the GM automatically. Hourly CH4 flux from the wetland ecosystem can be calculated easily by measuring continuously the changes in CH4 concentration in air, air temperature and pressure in the GM. The method showed that monthly CH4 flux varied from 0.39 to 1.11 g C m-2 month-1 from April to November and the CH4 emission for the plant growing season (eight months) was 5.64 g C m-2. The CGEF has an advantage in studying total CH4 emission from soil to the atmosphere through plant-mediated transport, diffusion and ebullition because of the large size of the GM.

  20. Incorporating Ecosystem Experiments and Observations into Process Models of Forest Carbon and Water Cycles: Challenges and Solutions

    Science.gov (United States)

    Ward, E. J.; Thomas, R. Q.; Sun, G.; McNulty, S. G.; Domec, J. C.; Noormets, A.; King, J. S.

    2015-12-01

    Numerous studies, both experimental and observational, have been conducted over the past two decades in an attempt to understand how water and carbon cycling in terrestrial ecosystems may respond to changes in climatic conditions. These studies have produced a wealth of detailed data on key processes driving these cycles. In parallel, sophisticated models of these processes have been formulated to answer a variety of questions relevant to natural resource management. Recent advances in data assimilation techniques offer exciting new possibilities to combine this wealth of ecosystem data with process models of ecosystem function to improve prediction and quantify associated uncertainty. Using forests of the southeastern United States as our focus, we will specify how fine-scale physiological (e.g. half-hourly sap flux) can be scaled up with quantified error for use in models of stand growth and hydrology. This approach represents an opportunity to leverage current and past research from experiments including throughfall displacement × fertilization (PINEMAP), irrigation × fertilization (SETRES), elevated CO­2­ (Duke and ORNL FACE) and a variety of observational studies in both conifer and hardwood forests throughout the region, using a common platform for data assimilation and prediction. As part of this discussion, we will address variation in dominant species, stand structure, site age, management practices, soils and climate that represent both challenges to the development of a common analytical approach and opportunities to address questions of interest to policy makers and natural resource managers.

  1. Nitrate removal in stream ecosystems measured by 15N addition experiments: Denitrification

    Science.gov (United States)

    Mulholland, P.J.; Hall, R.O.; Sobota, D.J.; Dodds, W.K.; Findlay, S.E.G.; Grimm, N. B.; Hamilton, S.K.; McDowell, W.H.; O'Brien, J. M.; Tank, J.L.; Ashkenas, L.R.; Cooper, L.W.; Dahm, Clifford N.; Gregory, S.V.; Johnson, S.L.; Meyer, J.L.; Peterson, B.J.; Poole, G.C.; Valett, H.M.; Webster, J.R.; Arango, C.P.; Beaulieu, J.J.; Bernot, M.J.; Burgin, A.J.; Crenshaw, C.L.; Helton, A.M.; Johnson, L.T.; Niederlehner, B.R.; Potter, J.D.; Sheibley, R.W.; Thomasn, S.M.

    2009-01-01

    We measured denitrification rates using a field 15N-NO- 3 tracer-addition approach in a large, cross-site study of nitrate uptake in reference, agricultural, and suburban-urban streams. We measured denitrification rates in 49 of 72 streams studied. Uptake length due to denitrification (SWden) ranged from 89 m to 184 km (median of 9050 m) and there were no significant differences among regions or land-use categories, likely because of the wide range of conditions within each region and land use. N2 production rates far exceeded N2O production rates in all streams. The fraction of total NO-3 removal from water due to denitrification ranged from 0.5% to 100% among streams (median of 16%), and was related to NHz 4 concentration and ecosystem respiration rate (ER). Multivariate approaches showed that the most important factors controlling SWden were specific discharge (discharge / width) and NO-3 concentration (positive effects), and ER and transient storage zones (negative effects). The relationship between areal denitrification rate (Uden) and NO- 3 concentration indicated a partial saturation effect. A power function with an exponent of 0.5 described this relationship better than a Michaelis-Menten equation. Although Uden increased with increasing NO- 3 concentration, the efficiency of NO-3 removal from water via denitrification declined, resulting in a smaller proportion of streamwater NO-3 load removed over a given length of stream. Regional differences in stream denitrification rates were small relative to the proximate factors of NO-3 concentration and ecosystem respiration rate, and land use was an important but indirect control on denitrification in streams, primarily via its effect on NO-3 concentration. ?? 2009.

  2. Evaluating pesticide effects on freshwater invertebrate communities in alpine environment: a model ecosystem experiment.

    Science.gov (United States)

    Ippolito, A; Carolli, M; Varolo, E; Villa, S; Vighi, M

    2012-10-01

    Pesticide loads in streams are potentially one of the most relevant stressors for macroinvertebrate communities. Nevertheless, real effects provoked at the community level are still largely unknown. Model ecosystems are frequently used as tools for the risk assessment of pesticides, especially for their regulation, however, they can be also applied to site-specific risk assessment in order to gain better understanding of the responses of aquatic ecosystems to chemical stress. In the present work, an experimental system was composed of 5 artificial streams that reproduced a mountain lotic environment under controlled conditions. This study was aimed to better understand, whether (and how) the biological community was influenced by pesticides pulse exposures. 5 mixture load events were simulated over the productive season (March-July 2010): biological community was regularly sampled and nominal concentrations of water were tested. The results were interpreted comparing the output of different metrics and statistical methodologies. The sensitivity of different metrics was analyzed considering single exposure events (maximum Toxic Units) as well as overall temporal trends. Results showed how some common taxonomic metrics (e.g. taxa richness, Shannon's index, total abundance of organisms, and the Extended Biotic Index) were not suitable to identify the effects of pesticides at community level. On the contrary EPT%, SPEAR(pesticide) and the Principal Response Curve methodology proved to be sensitive to this kind of stress, providing comparable results. Temporal trends of these metrics proved to be related to the concentration of chemicals. Remarkably, the first Principal Response Curve illustrates the trend followed by the most vulnerable species, while the second is more related to the trend of opportunistic species. A high potential risk for the invertebrate community was highlighted by a statistically significant decline of 40 points (comparison with the control) in

  3. Transdisciplinary synthesis for ecosystem science, policy and management: The Australian experience.

    Science.gov (United States)

    Lynch, A J J; Thackway, R; Specht, A; Beggs, P J; Brisbane, S; Burns, E L; Byrne, M; Capon, S J; Casanova, M T; Clarke, P A; Davies, J M; Dovers, S; Dwyer, R G; Ens, E; Fisher, D O; Flanigan, M; Garnier, E; Guru, S M; Kilminster, K; Locke, J; Mac Nally, R; McMahon, K M; Mitchell, P J; Pierson, J C; Rodgers, E M; Russell-Smith, J; Udy, J; Waycott, M

    2015-11-15

    Mitigating the environmental effects of global population growth, climatic change and increasing socio-ecological complexity is a daunting challenge. To tackle this requires synthesis: the integration of disparate information to generate novel insights from heterogeneous, complex situations where there are diverse perspectives. Since 1995, a structured approach to inter-, multi- and trans-disciplinary(1) collaboration around big science questions has been supported through synthesis centres around the world. These centres are finding an expanding role due to ever-accumulating data and the need for more and better opportunities to develop transdisciplinary and holistic approaches to solve real-world problems. The Australian Centre for Ecological Analysis and Synthesis (ACEAS ) has been the pioneering ecosystem science synthesis centre in the Southern Hemisphere. Such centres provide analysis and synthesis opportunities for time-pressed scientists, policy-makers and managers. They provide the scientific and organisational environs for virtual and face-to-face engagement, impetus for integration, data and methodological support, and innovative ways to deliver synthesis products. We detail the contribution, role and value of synthesis using ACEAS to exemplify the capacity for synthesis centres to facilitate trans-organisational, transdisciplinary synthesis. We compare ACEAS to other international synthesis centres, and describe how it facilitated project teams and its objective of linking natural resource science to policy to management. Scientists and managers were brought together to actively collaborate in multi-institutional, cross-sectoral and transdisciplinary research on contemporary ecological problems. The teams analysed, integrated and synthesised existing data to co-develop solution-oriented publications and management recommendations that might otherwise not have been produced. We identify key outcomes of some ACEAS working groups which used synthesis to

  4. Drought-associated changes in climate and their relevance for ecosystem experiments and models

    Directory of Open Access Journals (Sweden)

    H. J. De Boeck

    2011-05-01

    Full Text Available Drought periods can have important impacts on plant productivity and ecosystem functioning, but climatic conditions other than the lack of precipitation during droughts have never been quantified and have therefore not been considered explicitly in both experimental and modeling studies. Here, we identify which climatic characteristics deviate from normal during droughts and how these deviations could affect plant responses. Analysis of 609 years of daily data from nine Western European meteorological stations reveals that droughts in the studied region are consistently associated with more sunshine (+45 %, increased mean (+1.6 °C and maximum (+2.8 °C air temperatures and vapour pressure deficits that were 51 % higher than under normal conditions. These deviations from normal increase significantly as droughts progress. Using the process-model ORCHIDEE, we simulated droughts consistent with the results of the dataset analysis and compared water and carbon exchange of three different vegetation types during such natural droughts and droughts in which only the precipitation was affected. The comparison revealed contrasting responses: carbon loss was higher under natural drought in grasslands, while increased carbon uptake was found especially in decidious forests. This difference was attributed to better access to water reserves in forest ecosystems which prevented drought stress. This demonstrates that the warmer and sunnier conditions naturally associated with droughts can either improve growth or aggravate drought-related stress, depending on water reserves. As the impacts of including or excluding climatic parameters that correlate with drought are substantial, we propose that both experimental and modeling efforts should take into account other environmental factors than merely precipitation.

  5. Can current moisture responses predict soil CO2 efflux under altered precipitation regimes? A synthesis of manipulation experiments

    DEFF Research Database (Denmark)

    Vicca, S.; Bahn, M.; Estiarte, M.

    2014-01-01

    dependencies of SCE. Hence, the most justified answer to the question of whether current moisture responses of SCE can be extrapolated to predict SCE under altered precipitation regimes is 'no' - as based on the most reliable data sets available. We strongly recommend that future experiments focus more...

  6. The TFTR maintenance manipulator

    International Nuclear Information System (INIS)

    Kungl, D.; Loesser, D.; Heitzenroeder, P.; Cerdan, G.

    1989-01-01

    TFTR plans to begin D-T experiments in mid 1990. The D-T experimental program will produce approximately one hundred shots, with a neutron generation rate of 10 19 neutrons per shot. This will result in high levels of activation in TFTR, especially in the vacuum vessel. The primary purpose of the Maintenance Manipulator is to provide a means of remotely performing certain defined maintenance and inspection tasks inside the vacuum torus so as to minimize personnel exposure to radiation. The manipulator consists of a six-link folding boom connected to a fixed boom on a movable carriage. The entire manipulator is housed in a vacuum antechamber connected to the vacuum torus, through a port formerly used for a vacuum pumping duct. The configuration extends 180 0 in either direction to provide complete coverage of the torus. The four 3500 l/s turbopumps which were formerly used in the pumping duct will be mounted on the antechamber. The manipulator will utilize two end effectors. The first, called a General Inspection Arm (GIA) provides a movable platform to an inspection camera and an in-vacuum leak detector. The second is a bilateral, force-reflecting pair of slave arms which utilize specially developed tools to perform several maintenance functions. All components except the slave arms are capable of operating in TFTR's vacuum environment and during 150 0 C bakeout of the torus. (orig.)

  7. A control method for manipulators with redundancy

    International Nuclear Information System (INIS)

    Furusho, Junji; Usui, Hiroyuki

    1989-01-01

    Redundant manipulators have more ability than nonredundant ones in many aspects such as avoiding obstacles, avoiding singular states, etc. In this paper, a control algorithm for redundant manipulators working under the circumstance in the presence of obstacles is presented. First, the measure of manipulability for robot manipulators under obstacle circumstances is defined. Then, the control algorithm for the obstacle avoidance is derived by using this measure of manipulability. The obstacle avoidance and the maintenance of good posture are simultaneously achieved by this algorithm. Lastly, an experiment and simulation results using an eight degree of freedom manipulator are shown. (author)

  8. Biodiversity increases the resistance of ecosystem productivity to climate extremes.

    Science.gov (United States)

    Isbell, Forest; Craven, Dylan; Connolly, John; Loreau, Michel; Schmid, Bernhard; Beierkuhnlein, Carl; Bezemer, T Martijn; Bonin, Catherine; Bruelheide, Helge; de Luca, Enrica; Ebeling, Anne; Griffin, John N; Guo, Qinfeng; Hautier, Yann; Hector, Andy; Jentsch, Anke; Kreyling, Jürgen; Lanta, Vojtěch; Manning, Pete; Meyer, Sebastian T; Mori, Akira S; Naeem, Shahid; Niklaus, Pascal A; Polley, H Wayne; Reich, Peter B; Roscher, Christiane; Seabloom, Eric W; Smith, Melinda D; Thakur, Madhav P; Tilman, David; Tracy, Benjamin F; van der Putten, Wim H; van Ruijven, Jasper; Weigelt, Alexandra; Weisser, Wolfgang W; Wilsey, Brian; Eisenhauer, Nico

    2015-10-22

    It remains unclear whether biodiversity buffers ecosystems against climate extremes, which are becoming increasingly frequent worldwide. Early results suggested that the ecosystem productivity of diverse grassland plant communities was more resistant, changing less during drought, and more resilient, recovering more quickly after drought, than that of depauperate communities. However, subsequent experimental tests produced mixed results. Here we use data from 46 experiments that manipulated grassland plant diversity to test whether biodiversity provides resistance during and resilience after climate events. We show that biodiversity increased ecosystem resistance for a broad range of climate events, including wet or dry, moderate or extreme, and brief or prolonged events. Across all studies and climate events, the productivity of low-diversity communities with one or two species changed by approximately 50% during climate events, whereas that of high-diversity communities with 16-32 species was more resistant, changing by only approximately 25%. By a year after each climate event, ecosystem productivity had often fully recovered, or overshot, normal levels of productivity in both high- and low-diversity communities, leading to no detectable dependence of ecosystem resilience on biodiversity. Our results suggest that biodiversity mainly stabilizes ecosystem productivity, and productivity-dependent ecosystem services, by increasing resistance to climate events. Anthropogenic environmental changes that drive biodiversity loss thus seem likely to decrease ecosystem stability, and restoration of biodiversity to increase it, mainly by changing the resistance of ecosystem productivity to climate events.

  9. What researchers told us about their experiences and expectations of scholarly communications ecosystems

    Directory of Open Access Journals (Sweden)

    Lorraine Estelle

    2017-03-01

    Full Text Available Publishers, vendors and librarians often discuss the needs of the researcher. However, it is not often that information professionals have the opportunity to sit down with a group of researchers, listen to their perspective and ask them questions. The UKSG One-Day Conference held in London in November 2016 offered such an opportunity with a panel session of researchers chaired by Charlie Rapple of Kudos. The researchers shared with us their frustrations about scholarly communications ecosystems and their ideas for improvements. A major source of frustration is the need for academics to publish, and publish well, to keep their jobs and progress. In doing so, they face what seem to be often insurmountable obstacles that they feel powerless to address or change. Themes of the session were the lack of incentives to peer review and join editorial boards, the role of social networking sites, open access and collaboration with libraries. The researchers who so generously gave us their time are Professor Andy Miah (University of Salford, Dr Mícheál Ó Fathartaigh (Dublin Business School and Dr Sabina Michnowicz (Hazard Centre, University College London.

  10. How emotions affect logical reasoning:Evidence from experiments with mood-manipulated participants, spider phobics, and people with exam anxiety

    Directory of Open Access Journals (Sweden)

    Nadine eJung

    2014-06-01

    Full Text Available Recent experimental studies show that emotions can have a significant effect on the way we think, decide, and solve problems. This paper presents a series of four experiments on how emotions affect logical reasoning. In two experiments different groups of participants first had to pass a manipulated intelligence test. Their emotional state was altered by giving them feedback, that they performed excellent, poor or on average. Then they completed a set of logical inference problems (with if p, then q statements either in a Wason selection task paradigm or problems from the logical propositional calculus. Problem content also had either a positive, negative or neutral emotional value. Results showed a clear effect of emotions on reasoning performance. Participants in negative mood performed worse than participants in positive mood, but both groups were outperformed by the neutral mood reasoners. Problem content also had an effect on reasoning performance. In a second set of experiments, participants with exam or spider phobia solved logical problems with contents that were related to their anxiety disorder (spiders or exams. Spider phobic participants’ performance was lowered by the spider-content, while exam anxious participants were not affected by the exam-related problem content. Overall, unlike some previous studies, no evidence was found that performance is improved when emotion and content are congruent. These results have consequences for cognitive reasoning research and also for cognitively oriented psychotherapy and the treatment of disorders like depression and anxiety.

  11. Design and performance of B4WarmED, an aboveground and belowground free-air warming experiment at the temperate-boreal forest ecotone

    Science.gov (United States)

    Conducting manipulative climate change experiments in forests is challenging, given their spatial heterogeneity and canopy complexity. One specific challenge involves warming both plants and soils to depth in ecosystems without much bare ground. We describe the design, implementation, and performanc...

  12. Millennium Ecosystem Assessment: MA Ecosystems

    Data.gov (United States)

    National Aeronautics and Space Administration — The Millennium Ecosystem Assessment: MA Ecosystems provides data and information on the extent and classification of ecosystems circa 2000, including coastal,...

  13. Assessing landscape experiences as a cultural ecosystem service in public infrastructure projects

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Lindhjem, Henrik; Magnussen, Kristin

    Undesirable landscape changes, especially from large infrastructure projects, may give rise to large welfare losses due to degraded landscape experiences. These losses are largely unaccounted for in Nordic countries’ planning processes. There is a need to develop practical methods of including...

  14. Effects of Water and Nitrogen Addition on Ecosystem Carbon Exchange in a Meadow Steppe

    Science.gov (United States)

    Wang, Yunbo; Jiang, Qi; Yang, Zhiming; Sun, Wei; Wang, Deli

    2015-01-01

    A changing precipitation regime and increasing nitrogen deposition are likely to have profound impacts on arid and semiarid ecosystem C cycling, which is often constrained by the timing and availability of water and nitrogen. However, little is known about the effects of altered precipitation and nitrogen addition on grassland ecosystem C exchange. We conducted a 3-year field experiment to assess the responses of vegetation composition, ecosystem productivity, and ecosystem C exchange to manipulative water and nitrogen addition in a meadow steppe. Nitrogen addition significantly stimulated aboveground biomass and net ecosystem CO2 exchange (NEE), which suggests that nitrogen availability is a primary limiting factor for ecosystem C cycling in the meadow steppe. Water addition had no significant impacts on either ecosystem C exchange or plant biomass, but ecosystem C fluxes showed a strong correlation with early growing season precipitation, rather than whole growing season precipitation, across the 3 experimental years. After we incorporated water addition into the calculation of precipitation regimes, we found that monthly average ecosystem C fluxes correlated more strongly with precipitation frequency than with precipitation amount. These results highlight the importance of precipitation distribution in regulating ecosystem C cycling. Overall, ecosystem C fluxes in the studied ecosystem are highly sensitive to nitrogen deposition, but less sensitive to increased precipitation. PMID:26010888

  15. Changes in rainfall patterns in Mediterranean ecosystems: the MIND project

    Directory of Open Access Journals (Sweden)

    Papale D

    2007-12-01

    Full Text Available Will Mediterranean terrestrial ecosystems be affected by the expected changes in precipitation regimes? If so, by how much and in which direction? These questions are at the basis of the research performed in context of the EU MIND project, whose key objectives were: i to investigate the potential effects of increasing drought on Mediterranean terrestrial ecosystems at the process, ecosystem and regional scales and ii to assess ecosystem vulnerability to changes in rainfall patterns. A network of experimental study sites has been created in Portugal, Spain, France and Italy, where field manipulations alter the amount of water available to the ecosystem. The most up-to-date methods of ecophysiology, micrometeorology, soil ecology and remote sensing have been used to elucidate the mechanisms that regulate the response of vegetation and soil to changes in water availability. This information is providing the basis for the implementation and validation of simulation models capable of predicting the drought response of Mediterranean terrestrial ecosystems, and their vulnerability to future climate change, on a larger scale. The out-coming results are elucidating how water availability affects plant ecophysiological processes, the dynamics of soil carbon and the overall exchange of mass and energy between the land and the atmosphere. This paper focuses on some of the important, yet preliminary, results on C and energy fluxes that have been obtained at the large scale troughfall manipulation experiment (Tolfa, Italy, in a forest dominated by Arbutus unedo L.

  16. The importance of vegetation density for tourists' wildlife viewing experience and satisfaction in African savannah ecosystems.

    Science.gov (United States)

    Arbieu, Ugo; Grünewald, Claudia; Schleuning, Matthias; Böhning-Gaese, Katrin

    2017-01-01

    Southern African protected areas (PAs) harbour a great diversity of animals, which represent a large potential for wildlife tourism. In this region, global change is expected to result in vegetation changes, such as bush encroachment and increases in vegetation density. However, little is known on the influence of vegetation structure on wildlife tourists' wildlife viewing experience and satisfaction. In this study, we collected data on vegetation structure and perceived mammal densities along 196 road transects (each 5 km long) and conducted a social survey with 651 questionnaires across four PAs in three Southern African countries. Our objectives were 1) to assess visitors' attitude towards vegetation, 2) to test the influence of perceived mammal density and vegetation structure on the easiness to spot animals, and 3) on visitors' satisfaction during their visit to PAs. Using a Boosted Regression Tree procedure, we found mostly negative non-linear relationships between vegetation density and wildlife tourists' experience, and positive relationships between perceived mammal densities and wildlife tourists' experience. In particular, wildlife tourists disliked road transects with high estimates of vegetation density. Similarly, the easiness to spot animals dropped at thresholds of high vegetation density and at perceived mammal densities lower than 46 individuals per road transect. Finally, tourists' satisfaction declined linearly with vegetation density and dropped at mammal densities smaller than 26 individuals per transect. Our results suggest that vegetation density has important impacts on tourists' wildlife viewing experience and satisfaction. Hence, the management of PAs in savannah landscapes should consider how tourists perceive these landscapes and their mammal diversity in order to maintain and develop a sustainable wildlife tourism.

  17. The importance of vegetation density for tourists’ wildlife viewing experience and satisfaction in African savannah ecosystems

    Science.gov (United States)

    Grünewald, Claudia; Schleuning, Matthias; Böhning-Gaese, Katrin

    2017-01-01

    Southern African protected areas (PAs) harbour a great diversity of animals, which represent a large potential for wildlife tourism. In this region, global change is expected to result in vegetation changes, such as bush encroachment and increases in vegetation density. However, little is known on the influence of vegetation structure on wildlife tourists’ wildlife viewing experience and satisfaction. In this study, we collected data on vegetation structure and perceived mammal densities along 196 road transects (each 5 km long) and conducted a social survey with 651 questionnaires across four PAs in three Southern African countries. Our objectives were 1) to assess visitors’ attitude towards vegetation, 2) to test the influence of perceived mammal density and vegetation structure on the easiness to spot animals, and 3) on visitors’ satisfaction during their visit to PAs. Using a Boosted Regression Tree procedure, we found mostly negative non-linear relationships between vegetation density and wildlife tourists’ experience, and positive relationships between perceived mammal densities and wildlife tourists’ experience. In particular, wildlife tourists disliked road transects with high estimates of vegetation density. Similarly, the easiness to spot animals dropped at thresholds of high vegetation density and at perceived mammal densities lower than 46 individuals per road transect. Finally, tourists’ satisfaction declined linearly with vegetation density and dropped at mammal densities smaller than 26 individuals per transect. Our results suggest that vegetation density has important impacts on tourists’ wildlife viewing experience and satisfaction. Hence, the management of PAs in savannah landscapes should consider how tourists perceive these landscapes and their mammal diversity in order to maintain and develop a sustainable wildlife tourism. PMID:28957420

  18. Intercomparison of Terrestrial Laser Scanning Instruments for Assessing Forested Ecosystems: A Brisbane Field Experiment

    Science.gov (United States)

    Armston, J.; Newnham, G.; Strahler, A. H.; Schaaf, C.; Danson, M.; Gaulton, R.; Zhang, Z.; Disney, M.; Sparrow, B.; Phinn, S. R.; Schaefer, M.; Burt, A.; Counter, S.; Erb, A.; Goodwin, N.; Hancock, S.; Howe, G.; Johansen, K.; Li, Z.; Lollback, G.; Martel, J.; Muir, J.; Paynter, I.; Saenz, E.; Scarth, P.; Tindall, D.; Walker, L.; Witte, C.; Woodgate, W.; Wu, S.

    2013-12-01

    During 28th July - 3rd August, 2013, an international group of researchers brought five terrestrial laser scanners (TLS) to long-term monitoring plots in three eucalyptus-dominated woodland sites near Brisbane, Queensland, Australia, to acquire scans at common locations for calibration and intercomparison.They included: DWEL - a dual-wavelength full-waveform laser scanner (Boston U., U. Massachusetts Lowell, U. Massachusetts Boston, USA) SALCA - a dual-wavelength full-waveform laser scanner (U. Salford, UK) CBL - a canopy biomass lidar, a small ultraportable low-cost multiple discrete return scanner (U. Massachusetts Boston, USA) Riegl VZ400 - a survey-grade commercial waveform scanner (Queensland Government and TERN, U. Queensland, Australia) FARO Focus 3D - a lightweight commercial phase-shift ranging laser scanner (U. Southern Queensland) Two plots were scanned at Karawatha Forest Park, a Terrestrial Ecosystem Research Network (TERN) Supersite, and one plot at D'Aguilar National Park. At each 50 x 100 m plot, a center scan point was surrounded by four scan points located 25 m away in a cross pattern allowing for 3-D reconstructions of scan sites in the form of point clouds. At several center points, multiple instrument configurations (i.e. different beam divergence, angular resolution, pulse rate) were acquired to test the impact of instrument specifications on separation of woody and non-woody materials and estimation of vegetation structure parameters. Three-dimensional Photopoint photographic panoramas were also acquired, providing reconstructions of stems in the form of point clouds using photogrammetric correlation methods. Calibrated reflectance targets were also scanned to compare instrument geometric and radiometric performance. Ancillary data included hemispherical photos, TRAC LAI/clumping measurements, spectra of leaves, bark, litter, and other target components. Wet and dry leaf weights determined water content. Planned intercomparison topics and

  19. Comprehensive ecosystem model-experiment synthesis using multiple datasets at two temperate forest free-air CO2 enrichment experiments: model performance and compensating biases

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Anthony P [ORNL; Hanson, Paul J [ORNL; DeKauwe, Martin G [Macquarie University; Medlyn, Belinda [Macquarie University; Zaehle, S [Max Planck Institute for Biogeochemistry; Asao, Shinichi [Colorado State University, Fort Collins; Dietze, Michael [University of Illinois, Urbana-Champaign; Hickler, Thomas [Goethe University, Frankfurt, Germany; Huntinford, Chris [Centre for Ecology and Hydrology, Wallingford, United Kingdom; Iversen, Colleen M [ORNL; Jain, Atul [University of Illinois, Urbana-Champaign; Lomas, Mark [University of Sheffield; Luo, Yiqi [University of Oklahoma; McCarthy, Heather R [Duke University; Parton, William [Colorado State University, Fort Collins; Prentice, I. Collin [Macquarie University; Thornton, Peter E [ORNL; Wang, Shusen [Canada Centre for Remote Sensing (CCRS); Wang, Yingping [CSIRO Marine and Atmospheric Research; Warlind, David [Lund University, Sweden; Weng, Ensheng [University of Oklahoma, Norman; Warren, Jeffrey [ORNL; Woodward, F. Ian [University of Sheffield; Oren, Ram [Duke University; Norby, Richard J [ORNL

    2014-01-01

    Free Air CO2 Enrichment (FACE) experiments provide a remarkable wealth of data to test the sensitivities of terrestrial ecosystem models (TEMs). In this study, a broad set of 11 TEMs were compared to 22 years of data from two contrasting FACE experiments in temperate forests of the south eastern US the evergreen Duke Forest and the deciduous Oak Ridge forest. We evaluated the models' ability to reproduce observed net primary productivity (NPP), transpiration and Leaf Area index (LAI) in ambient CO2 treatments. Encouragingly, many models simulated annual NPP and transpiration within observed uncertainty. Daily transpiration model errors were often related to errors in leaf area phenology and peak LAI. Our analysis demonstrates that the simulation of LAI often drives the simulation of transpiration and hence there is a need to adopt the most appropriate of hypothesis driven methods to simulate and predict LAI. Of the three competing hypotheses determining peak LAI (1) optimisation to maximise carbon export, (2) increasing SLA with canopy depth and (3) the pipe model the pipe model produced LAI closest to the observations. Modelled phenology was either prescribed or based on broader empirical calibrations to climate. In some cases, simulation accuracy was achieved through compensating biases in component variables. For example, NPP accuracy was sometimes achieved with counter-balancing biases in nitrogen use efficiency and nitrogen uptake. Combined analysis of parallel measurements aides the identification of offsetting biases; without which over-confidence in model abilities to predict ecosystem function may emerge, potentially leading to erroneous predictions of change under future climates.

  20. Marine ecosystem community carbon and nutrient uptake stoichiometry under varying ocean acidification during the PeECE III experiment

    Directory of Open Access Journals (Sweden)

    R. G. J. Bellerby

    2008-11-01

    Full Text Available Changes to seawater inorganic carbon and nutrient concentrations in response to the deliberate CO2 perturbation of natural plankton assemblages were studied during the 2005 Pelagic Ecosystem CO2 Enrichment (PeECE III experiment. Inverse analysis of the temporal inorganic carbon dioxide system and nutrient variations was used to determine the net community stoichiometric uptake characteristics of a natural pelagic ecosystem perturbed over a range of pCO2 scenarios (350, 700 and 1050 μatm. Nutrient uptake showed no sensitivity to CO2 treatment. There was enhanced carbon production relative to nutrient consumption in the higher CO2 treatments which was positively correlated with the initial CO2 concentration. There was no significant calcification response to changing CO2 in Emiliania huxleyi by the peak of the bloom and all treatments exhibited low particulate inorganic carbon production (~15 μmol kg−1. With insignificant air-sea CO2 exchange across the treatments, the enhanced carbon uptake was due to increase organic carbon production. The inferred cumulative C:N:P stoichiometry of organic production increased with CO2 treatment from 1:6.3:121 to 1:7.1:144 to 1:8.25:168 at the height of the bloom. This study discusses how ocean acidification may incur modification to the stoichiometry of pelagic production and have consequences for ocean biogeochemical cycling.

  1. Response and recovery of a pristine groundwater ecosystem impacted by toluene contamination - A meso-scale indoor aquifer experiment

    Science.gov (United States)

    Herzyk, Agnieszka; Fillinger, Lucas; Larentis, Michael; Qiu, Shiran; Maloszewski, Piotr; Hünniger, Marko; Schmidt, Susanne I.; Stumpp, Christine; Marozava, Sviatlana; Knappett, Peter S. K.; Elsner, Martin; Meckenstock, Rainer; Lueders, Tillmann; Griebler, Christian

    2017-12-01

    Microbial communities are the driving force behind the degradation of contaminants like aromatic hydrocarbons in groundwater ecosystems. However, little is known about the response of native microbial communities to contamination in pristine environments as well as their potential to recover from a contamination event. Here, we used an indoor aquifer mesocosm filled with sandy quaternary calciferous sediment that was continuously fed with pristine groundwater to study the response, resistance and resilience of microbial communities to toluene contamination over a period of almost two years, comprising 132 days of toluene exposure followed by nearly 600 days of recovery. We observed an unexpectedly high intrinsic potential for toluene degradation, starting within the first two weeks after the first exposure. The contamination led to a shift from oxic to anoxic, primarily nitrate-reducing conditions as well as marked cell growth inside the contaminant plume. Depth-resolved community fingerprinting revealed a low resistance of the native microbial community to the perturbation induced by the exposure to toluene. Distinct populations that were dominated by a small number of operational taxonomic units (OTUs) rapidly emerged inside the plume and at the plume fringes, partially replacing the original community. During the recovery period physico-chemical conditions were restored to the pristine state within about 35 days, whereas the recovery of the biological parameters was much slower and the community composition inside the former plume area had not recovered to the original state by the end of the experiment. These results demonstrate the low resilience of sediment-associated groundwater microbial communities to organic pollution and underline that recovery of groundwater ecosystems cannot be assessed solely by physico-chemical parameters.

  2. Reactivation of a cryptobiotic stream ecosystem in the McMurdo Dry Valleys, Antarctica: A long-term geomorphological experiment

    Science.gov (United States)

    McKnight, Diane M.; Tate, C.M.; Andrews, E.D.; Niyogi, D.K.; Cozzetto, K.; Welch, K.; Lyons, W.B.; Capone, D.G.

    2007-01-01

    The McMurdo Dry Valleys of Antarctica contain many glacial meltwater streams that flow for 6 to 12??weeks during the austral summer and link the glaciers to the lakes on the valley floors. Dry valley streams gain solutes longitudinally through weathering reactions and microbial processes occurring in the hyporheic zone. Some streams have thriving cyanobacterial mats. In streams with regular summer flow, the mats are freeze-dried through the winter and begin photosynthesizing with the onset of flow. To evaluate the longer term persistence of cyanobacterial mats, we diverted flow to an abandoned channel, which had not received substantial flow for approximately two decades. Monitoring of specific conductance showed that for the first 3??years after the diversion, the solute concentrations were greater in the reactivated channel than in most other dry valley streams. We observed that cyanobacterial mats became abundant in the reactivated channel within a week, indicating that the mats had been preserved in a cryptobiotic state in the channel. Over the next several years, these mats had high rates of productivity and nitrogen fixation compared to mats from other streams. Experiments in which mats from the reactivated channel and another stream were incubated in water from both of the streams indicated that the greater solute concentrations in the reactivated channel stimulated net primary productivity of mats from both streams. These stream-scale experimental results indicate that the cryptobiotic preservation of cyanobacterial mats in abandoned channels in the dry valleys allows for rapid response of these stream ecosystems to climatic and geomorphological change, similar to other arid zone stream ecosystems. ?? 2006 Elsevier B.V. All rights reserved.

  3. Effects of red-backed salamanders on ecosystem functions.

    Directory of Open Access Journals (Sweden)

    Daniel J Hocking

    Full Text Available Ecosystems provide a vast array of services for human societies, but understanding how various organisms contribute to the functions that maintain these services remains an important ecological challenge. Predators can affect ecosystem functions through a combination of top-down trophic cascades and bottom-up effects on nutrient dynamics. As the most abundant vertebrate predator in many eastern US forests, woodland salamanders (Plethodon spp. likely affect ecosystems functions. We examined the effects of red-backed salamanders (Plethodon cinereus on a variety of forest ecosystem functions using a combined approach of large-scale salamander removals (314-m(2 plots and small-scale enclosures (2 m(2 where we explicitly manipulated salamander density (0, 0.5, 1, 2, 4 m(-2. In these experiments, we measured the rates of litter and wood decomposition, potential nitrogen mineralization and nitrification rates, acorn germination, and foliar insect damage on red oak seedlings. Across both experimental venues, we found no significant effect of red-backed salamanders on any of the ecosystem functions. We also found no effect of salamanders on intraguild predator abundance (carabid beetles, centipedes, spiders. Our study adds to the already conflicting evidence on effects of red-backed salamander and other amphibians on terrestrial ecosystem functions. It appears likely that the impact of terrestrial amphibians on ecosystem functions is context dependent. Future research would benefit from explicitly examining terrestrial amphibian effects on ecosystem functions under a variety of environmental conditions and in different forest types.

  4. Effects of red-backed salamanders on ecosystem functions.

    Science.gov (United States)

    Hocking, Daniel J; Babbitt, Kimberly J

    2014-01-01

    Ecosystems provide a vast array of services for human societies, but understanding how various organisms contribute to the functions that maintain these services remains an important ecological challenge. Predators can affect ecosystem functions through a combination of top-down trophic cascades and bottom-up effects on nutrient dynamics. As the most abundant vertebrate predator in many eastern US forests, woodland salamanders (Plethodon spp.) likely affect ecosystems functions. We examined the effects of red-backed salamanders (Plethodon cinereus) on a variety of forest ecosystem functions using a combined approach of large-scale salamander removals (314-m(2) plots) and small-scale enclosures (2 m(2)) where we explicitly manipulated salamander density (0, 0.5, 1, 2, 4 m(-2)). In these experiments, we measured the rates of litter and wood decomposition, potential nitrogen mineralization and nitrification rates, acorn germination, and foliar insect damage on red oak seedlings. Across both experimental venues, we found no significant effect of red-backed salamanders on any of the ecosystem functions. We also found no effect of salamanders on intraguild predator abundance (carabid beetles, centipedes, spiders). Our study adds to the already conflicting evidence on effects of red-backed salamander and other amphibians on terrestrial ecosystem functions. It appears likely that the impact of terrestrial amphibians on ecosystem functions is context dependent. Future research would benefit from explicitly examining terrestrial amphibian effects on ecosystem functions under a variety of environmental conditions and in different forest types.

  5. Enhancing the Understanding of Marine Ecosystems through Teleducation and Field Experiences

    Science.gov (United States)

    Macko, S.

    2006-12-01

    This project is an outreach and education program with a partner in the K-12 schools at Accomack County on the Eastern Shore of Virginia. It endeavors to build a community more knowledgeable of the importance the ocean plays daily in our lives, and our own impact on the ocean. It is an program built in stages that: 1) Establish high speed teleducation linkages with Eastern Shore of Virginia High Schools, for live interactive, classes (teleducation) for earth science teachers enabling them to remotely participate in University of Virginia classes in Oceanography (designed on a faculty development basis or acquire NSTA certification in Earth Science Education, as well as participation by seniors in the Accomack Schools; 2) Establish field experiences for teachers and selected students that involve travel to both the Virginia Coast Reserve Long Term Ecological Research (VCR/LTER) Center, UVA and the NOAA Beaufort, NC Laboratory to observe first- hand the science programs at those locations and participate in cutting edge coastal marine research efforts. These experiences will not only improve student understanding of the ocean-atmosphere biogeophysical system, but also encourage students to explore the sciences as a field of study and possible vocation. Advanced high school students and science teachers from Accomack County Public Schools participated in an experience involving field and laboratory methods employed in a NSF-sponsored study of the coupled natural-human dynamics on the Eastern Shore of Virginia over the past 500 years (NSF-Biocomplexity). Students and teachers worked with researchers of the VCR facility in Oyster, VA, collected sediment cores from Chesapeake Bay tributaries, and traveled to the Organic Geochemistry Laboratory at UVA, in Charlottesville, VA to prepare and analyze samples for isotopic and palynological information. In a first of its kind connectivity, in June/July, 2006, using high speed internet connections, a summer class in

  6. Are large-scale flow experiments informing the science and management of freshwater ecosystems?

    Science.gov (United States)

    Olden, Julian D.; Konrad, Christopher P.; Melis, Theodore S.; Kennard, Mark J.; Freeman, Mary C.; Mims, Meryl C.; Bray, Erin N.; Gido, Keith B.; Hemphill, Nina P.; Lytle, David A.; McMullen, Laura E.; Pyron, Mark; Robinson, Christopher T.; Schmidt, John C.; Williams, John G.

    2013-01-01

    Greater scientific knowledge, changing societal values, and legislative mandates have emphasized the importance of implementing large-scale flow experiments (FEs) downstream of dams. We provide the first global assessment of FEs to evaluate their success in advancing science and informing management decisions. Systematic review of 113 FEs across 20 countries revealed that clear articulation of experimental objectives, while not universally practiced, was crucial for achieving management outcomes and changing dam-operating policies. Furthermore, changes to dam operations were three times less likely when FEs were conducted primarily for scientific purposes. Despite the recognized importance of riverine flow regimes, four-fifths of FEs involved only discrete flow events. Over three-quarters of FEs documented both abiotic and biotic outcomes, but only one-third examined multiple taxonomic responses, thus limiting how FE results can inform holistic dam management. Future FEs will present new opportunities to advance scientifically credible water policies.

  7. Preferences for Management of Near-Shore Marine Ecosystems: A Choice Experiment in New Zealand

    Directory of Open Access Journals (Sweden)

    Sophal Chhun

    2013-09-01

    Full Text Available There is considerable interest in New Zealand in establishing “Customary Management Areas” (taiāpure and mātaitai and Marine Reserves to support Māori cultural practices and restore declining biodiversity and fish stocks. Allocation of near-shore marine areas for these management systems potentially benefits the larger public, but it has often been vigorously opposed by recreational and commercial fishers. This paper reports estimates of the relative values held by the public toward four potentially conflicting uses of near-shore marine areas. These estimates come from a web-based choice survey completed by 1055 respondents recruited from throughout New Zealand. The response rate was especially high at 60%. We present results weighted to the characteristics of the population and test the results against a variety of well-known sources of survey bias. Scenario development suggests that some reallocation of near-shore marine areas to any of the management systems under discussion alternative to the status quo is likely to yield a welfare gain. A combination of marine reserves and taiāpure is most preferred. The exercise supports the use of discrete choice experiments to provide crucial information about difficult-to-quantify public values for aspects of management of near-shore marine areas, such as proposed taiāpure, mātaitai, or marine reserves.

  8. Peeking at ecosystem stability: making use of a natural disturbance experiment to analyze resistance and resilience.

    Science.gov (United States)

    Bruelheide, Helge; Luginbühl, Ute

    2009-05-01

    To determine which factors contribute most to the stability of species composition in a beech forest after profound disturbance, we made use of a natural experiment caused by a severe windthrow that occurred at a permanent monitoring site in an old beech forest in Lower Saxony (Germany). The floristic composition was recorded for the succeeding five years after the disturbance and used to derive measures of resistance and resilience for plots as well as for individual species. Due to the existence of previously established randomly distributed permanent plots, we had precise information of the pre-disturbance state, including initial cover of the herb layer, species richness, and species composition. Variables describing the floristic change, resistance, and resilience were derived from correspondence analysis allowing for partitioning the effects of variation among plots from those of temporal change. We asked to which degree these variables could be predicted by pre-disturbance state and disturbance intensity. We found that both the pre-disturbance state and the disturbance intensity were good predictors for floristic change and resistance, while they failed to predict resilience. Among the descriptors of the pre-disturbance state the initial cover of the herb layer turned out to be a useful predictor, which is explained by a high vegetation cover buffering against losses and preventing establishment of newcomers. In contrast, species number neither showed a relationship to floristic change nor to resistance. Putative positive effects of species number on stability according to the insurance hypothesis might have been counterbalanced by a disruption of niche complementarity in species-rich communities. Among the descriptors of disturbance intensity, the loss in canopy cover and the change in photosynthetically active radiation after the storm were equally good predictors for the change in floristic composition and resistance. The analysis of the responses of

  9. Whole-ecosystem nitrogen effects research in Europe

    International Nuclear Information System (INIS)

    Sullivan, T.J.

    1993-01-01

    There has been an enormous increase during the past few years in the amount of research being conducted in Europe on the effects of atmospheric deposition of nitrogen on aquatic, and especially terrestrial, ecosystems. Nitrogen deposition increases the emissions of N 2 O from forest soils and may decrease CH 4 uptake. Both increased N 2 O production and decreased CH 4 consumption would increase the concentration of greenhouse gases in the atmosphere. Thus there are important linkages between nitrogen deposition (and consequent ecosystem effects) and the release of greenhouse gases that have been implicated in potential global climate change. This paper summarises some of the European research that has been carried out in recent years. The experimental approach has shifted heavily into whole-ecosystem experimental manipulations, which are being conducted across gradients of atmospheric deposition and other environmental factors. Manipulations are focused primarily on coniferous forest ecosystems and involve increasing ambient deposition of sulfur and nitrogen; excluding ambient deposition via the construction of roofs over entire forested plots or catchments; and manipulating climatic factors, especially water availability. Experiments are designed to continue for long periods (i.e., 5-10 years) and are augmented by detailed, process-level studies at the manipulation sites. Results of the broad-scale and detailed studies are being used to build, test, and validate mathematical models that simulate nitrogen processing, nutrient cycling, and water regulation in coniferous forest ecosystems under varying depositional and climatic regimes. Ultimately, these models will be used to predict nitrogen saturation, estimate the critical loads of nitrogen for European forests, and specify emission controls needed to protect European forests and surface waters from the detrimental effects of excess nitrogen deposition. 19 refs., 1 fig., 2 photos

  10. Regional zooplankton dispersal provides spatial insurance for ecosystem function.

    Science.gov (United States)

    Symons, Celia C; Arnott, Shelley E

    2013-05-01

    Changing environmental conditions are affecting diversity and ecosystem function globally. Theory suggests that dispersal from a regional species pool may buffer against changes in local community diversity and ecosystem function after a disturbance through the establishment of functionally redundant tolerant species. The spatial insurance provided by dispersal may decrease through time after environmental change as the local community monopolizes resources and reduces community invasibility. To test for evidence of the spatial insurance hypothesis and to determine the role dispersal timing plays in this response we conducted a field experiment using crustacean zooplankton communities in a subarctic region that is expected to be highly impacted by climate change - Churchill, Canada. Three experiments were conducted where nutrients, salt, and dispersal were manipulated. The three experiments differed in time-since-disturbance that the dispersers were added. We found that coarse measures of diversity (i.e. species richness, evenness, and Shannon-Weiner diversity) were generally resistant to large magnitude disturbances, and that dispersal had the most impact on diversity when dispersers were added shortly after disturbance. Ecosystem functioning (chl-a) was degraded in disturbed communities, but dispersal recovered ecosystem function to undisturbed levels. This spatial insurance for ecosystem function was mediated through changes in community composition and the relative abundance of functional groups. Results suggest that regional diversity and habitat connectivity will be important in the future to maintain ecosystem function by introducing functionally redundant species to promote compensatory dynamics. © 2012 Blackwell Publishing Ltd.

  11. Ecosystem Services

    Science.gov (United States)

    Ecosystem goods and services are the many life-sustaining benefits we receive from nature and contribute to environmental and human health and well-being. Ecosystem-focused research will develop methods to measure ecosystem goods and services.

  12. Experimental Whole-Ecosystem Warming Alters Vegetation Phenology in a Boreal Spruce Bog: Initial Results from the SPRUCE Experiment

    Science.gov (United States)

    Richardson, A. D.

    2016-12-01

    Phenology is one of the most robust indicators of the biological impacts of global change. However, the response of phenology to future environmental conditions still remains highly uncertain because of the challenges associated with conducting realistic manipulative experiments. At the SPRUCE (Spruce and Peatland Responses Under Climatic and Environmental Change) experiment in the north-central United States, experimental temperature (0 to +9°C above ambient) and CO2 (ambient and elevated) treatments are being applied to mature, and intact, Picea mariana-Sphagnum spp. bog communities in their native habitat through the use of ten large (approximately 12 m wide, 10 m high) open-topped enclosures. We are tracking vegetation green-up and senescence in these chambers using repeat digital photography. Within each chamber, images are recorded every 30 minutes and uploaded to PhenoCam (http://phenocam.sr.unh.edu), where processed to yield quantitative measures of canopy color. These data are complemented by on-the-ground phenological data collected by human observers. Air warming treatments at SPRUCE began in August 2015. We observed a delay in senescence during autumn 2015 (2-5 days per degree of warming) and an advance in onset during spring 2016 (1-4 days per degree of warming). These patterns are robust across species and methods of phenological observation (i.e. camera-based vs. human observer). And, our results show very little evidence for photoperiod acting as a constraint on the response to warming. Early spring onset and consequent loss of frost hardiness in the warmest chambers proved disadvantageous when a brief period of extreme cold (to -12°C in the control chambers, to -3°C in the +9°C chambers) followed a month of generally mild weather. Foliage mortality for both Larix and Picea was immediate and severe, although both species subsequently re-flushed. These results give support for the hypothesis that warming may enhance the likelihood of spring frost

  13. Diagnosing and Assessing Uncertainties of the Carbon Cycle in Terrestrial Ecosystem Models from a Multi-Model Ensemble Experiment

    Science.gov (United States)

    Wang, W.; Dungan, J. L.; Hashimoto, H.; Michaelis, A.; Milesi, C.; Ichii, K.; Nemani, R. R.

    2009-12-01

    We are conducting an ensemble modeling exercise using the Terrestrial Observation and Prediction System (TOPS) to characterize structural uncertainty in carbon fluxes and stocks estimates from different ecosystem models. The experiment uses public-domain versions of Biome-BGC, LPJ, TOPS-BGC, and CASA, driven by a consistent set of climate fields for North America at 8km resolution and daily/monthly time steps over the period of 1982-2006. A set of diagnostics is developed to characterize the behavior of the models in the climate (temperature-precipitation) space, and to evaluate the simulated carbon cycle in an integrated way. The key findings of this study include that: (relative) optimal primary production is generally found in climate regions where the relationship between annual temperature (T, oC) and precipitation (P, mm) is defined by P = 50*T+500; the ratios between NPP and GPP are close to 50% on average, yet can vary between models and in different climate regions; the allocation of carbon to leaf growth represents a positive feedback to the primary production, and different approaches to constrain this process have significant impacts on the simulated carbon cycle; substantial differences in biomass stocks may be induced by small differences in the tissue turnover rate and the plant mortality; the mean residence time of soil carbon pools is strongly influenced by schemes of temperature regulations; non-respiratory disturbances (e.g., fires) are the main driver for NEP, yet its magnitudes vary between models. Overall, these findings indicate that although the structures of the models are similar, the uncertainties among them can be large, highlighting the problem inherent in relying on only one modeling approach to map surface carbon fluxes or to assess vegetation-climate interactions.

  14. Towards a consistent approach for ecosystem accounting

    NARCIS (Netherlands)

    Edens, B.; Hein, L.G.

    2013-01-01

    In spite of an increasing interest in environmental economic accounting, there is still very limited experience with the integration of ecosystem services and ecosystem capital in national accounts. This paper identifies four key methodological challenges in developing ecosystem accounts: the

  15. River food web response to large-scale riparian zone manipulations.

    Directory of Open Access Journals (Sweden)

    J Timothy Wootton

    Full Text Available Conservation programs often focus on select species, leading to management plans based on the autecology of the focal species, but multiple ecosystem components can be affected both by the environmental factors impacting, and the management targeting, focal species. These broader effects can have indirect impacts on target species through the web of interactions within ecosystems. For example, human activity can strongly alter riparian vegetation, potentially impacting both economically-important salmonids and their associated river food web. In an Olympic Peninsula river, Washington state, USA, replicated large-scale riparian vegetation manipulations implemented with the long-term (>40 yr goal of improving salmon habitat did not affect water temperature, nutrient limitation or habitat characteristics, but reduced canopy cover, causing reduced energy input via leaf litter, increased incident solar radiation (UV and PAR and increased algal production compared to controls. In response, benthic algae, most insect taxa, and juvenile salmonids increased in manipulated areas. Stable isotope analysis revealed a predominant contribution of algal-derived energy to salmonid diets in manipulated reaches. The experiment demonstrates that riparian management targeting salmonids strongly affects river food webs via changes in the energy base, illustrates how species-based management strategies can have unanticipated indirect effects on the target species via the associated food web, and supports ecosystem-based management approaches for restoring depleted salmonid stocks.

  16. Currency Manipulation versus Current Account Manipulation

    OpenAIRE

    Junning Cai

    2005-01-01

    It is said that a country’s currency peg can become currency manipulation representing protracted government intervention in the foreign exchange market that gives it unfair competitive advantage in international trade yet prevents effective balance of payments in its trade partners. Regarding this widespread fallacy, this paper explains why currency peg is not currency manipulation even when it keeps a country’s currency undervalued. We clarify that 1) government is inherently a major player...

  17. Assessing atmospheric nitrogen deposition to natural and semi-natural ecosystemsexperience from Danish studies using the DAMOS system

    DEFF Research Database (Denmark)

    Hertel, Ole; Geels, Camilla; Frohn, Lise

    2013-01-01

    and ammonium (reaction products of nitrogen oxides and ammonia), but also dry deposition of other reactive nitrogen compounds (mainly nitrogen oxides in the form of gas phase nitric acid and nitrogen dioxide). In Denmark's environmental management of the sensitive terrestrial ecosystems modelling tools...... are required that account for both the local and the long-range transported contributions. This motivated development of the Danish Ammonia MOdelling System (DAMOS) that has been successfully applied to the assessment of atmospheric nitrogen loadings to sensitive Danish ecosystems. We present here three...... different examples of such assessments. Our results show that ecosystems located in Western Denmark (Case 1) receive the highest loads of atmospheric nitrogen depositions which generally exceed the critical load. This part of the country has the highest livestock density. In the Eastern part of the country...

  18. Bottom-up effects on biomass versus top-down effects on identity: a multiple-lake fish community manipulation experiment

    NARCIS (Netherlands)

    Lemmens, P.; Declerck, S.A.J.; Tuytens, K.; Vanderstukken, M.; De Meester, L.

    2018-01-01

    The extent to which ecosystems are regulated by top-down relative to bottom-up control has been a dominant paradigm in ecology for many decades. For lakes, it has been shown that predation by fish is an important determinant of variation in zooplankton and phytoplankton community characteristics.

  19. Are rocky shore ecosystems affected by nutrient-enriched seawater? Some preliminary results from a mesocosm experiment

    NARCIS (Netherlands)

    Bokn, T.L.; Moy, F.E.; Christie, H.; Engelbert, S.; Karez, R.; Kersting, K.; Kraufvelin, P.; Lindblad, C.; Marba, N.; Pedersen, M.F.; Sorensen, K.

    2002-01-01

    The response of rocky shore ecosystems to increased nutrient availability was examined in eight land-based mesocosms designed for hard-bottom littoral communities built at Marine Research Station Solbergstrand (Norway). The average seawater volume in each basin was 9 m3 with an average water

  20. Experiences in multiyear combined state-parameter estimation with an ecosystem model of the North Atlantic and Arctic Oceans using the Ensemble Kalman Filter

    Science.gov (United States)

    Simon, Ehouarn; Samuelsen, Annette; Bertino, Laurent; Mouysset, Sandrine

    2015-12-01

    A sequence of one-year combined state-parameter estimation experiments has been conducted in a North Atlantic and Arctic Ocean configuration of the coupled physical-biogeochemical model HYCOM-NORWECOM over the period 2007-2010. The aim is to evaluate the ability of an ensemble-based data assimilation method to calibrate ecosystem model parameters in a pre-operational setting, namely the production of the MyOcean pilot reanalysis of the Arctic biology. For that purpose, four biological parameters (two phyto- and two zooplankton mortality rates) are estimated by assimilating weekly data such as, satellite-derived Sea Surface Temperature, along-track Sea Level Anomalies, ice concentrations and chlorophyll-a concentrations with an Ensemble Kalman Filter. The set of optimized parameters locally exhibits seasonal variations suggesting that time-dependent parameters should be used in ocean ecosystem models. A clustering analysis of the optimized parameters is performed in order to identify consistent ecosystem regions. In the north part of the domain, where the ecosystem model is the most reliable, most of them can be associated with Longhurst provinces and new provinces emerge in the Arctic Ocean. However, the clusters do not coincide anymore with the Longhurst provinces in the Tropics due to large model errors. Regarding the ecosystem state variables, the assimilation of satellite-derived chlorophyll concentration leads to significant reduction of the RMS errors in the observed variables during the first year, i.e. 2008, compared to a free run simulation. However, local filter divergences of the parameter component occur in 2009 and result in an increase in the RMS error at the time of the spring bloom.

  1. Getting Manipulative about Math.

    Science.gov (United States)

    Scheer, Janet K.; And Others

    1984-01-01

    Math manipulatives that are made from inexpensive, common items help students understand basic mathematics concepts. Learning activities using Cheerios, jellybeans, and clay as teaching materials are suggested. (DF)

  2. Alpine ecosystems

    Science.gov (United States)

    P.W. Rundel; C.I. Millar

    2016-01-01

    Alpine ecosystems are typically defined as those areas occurring above treeline, while recognizing that alpine ecosystems at a local scale may be found below this boundary for reasons including geology, geomorphology, and microclimate. The lower limit of the alpine ecosystems, the climatic treeline, varies with latitude across California, ranging from about 3500 m in...

  3. Ecosystem engineering potential of the gastropod Terebralia palustris (Linnaeus, 1767) in mangrove wastewater wetlands - A controlled mesocosm experiment

    Energy Technology Data Exchange (ETDEWEB)

    Penha-Lopes, Gil, E-mail: gil.penha-lopes@biology-research.co [Centro de Oceanografia - Laboratorio Maritimo da Guia, Departamento de Biologia Animal, Faculdade de Ciencias da Universidade de Lisboa, Avenida Na, Senhora do Cabo 939, 2750-374 Cascais (Portugal); Department of Analytical and Environmental Chemistry, Vrije Universiteit Brussels, Brussels (Belgium); Bartolini, Fabrizio [Dipartimento di Biologia Evoluzionistica, Universita degli Studi di Firenze, via Romana 17, I-50125 Firenze (Italy); Limbu, Samwel [University of Dar es Salaam, Department of Aquatic Sciences and Fisheries, P.O. Box 35064, Dar es Salaam (Tanzania, United Republic of); Cannicci, Stefano [Dipartimento di Biologia Evoluzionistica, Universita degli Studi di Firenze, via Romana 17, I-50125 Firenze (Italy); Mgaya, Yunus [University of Dar es Salaam, Department of Aquatic Sciences and Fisheries, P.O. Box 35064, Dar es Salaam (Tanzania, United Republic of); Kristensen, Erik [Institute of Biology, University of Southern Denmark, DK-5230 Odense M (Denmark); Paula, Jose [Centro de Oceanografia - Laboratorio Maritimo da Guia, Departamento de Biologia Animal, Faculdade de Ciencias da Universidade de Lisboa, Avenida Na, Senhora do Cabo 939, 2750-374 Cascais (Portugal)

    2010-01-15

    The effect of different sewage concentrations (0, 20, 60 and 100%), vegetation (Bare, Avicennia marina or Rhizophora mucronata) and immersion periods (immersion/emersion period of 12/12 h or 3/3 days just for 100%) conditions were studied for 6 months on survival and growth rates of Terebralia palustris (Linnaeus, 1767). Gastropods' activity and ecosystem engineering preformed at bare and A. marina planted cells and 3 sewage conditions (0, 20 and 60%) were determined. Survival rates were higher than 70% in all treatments. Growth rate decreased significantly with increasing sewage concentrations (mainly at unplanted conditions) and longer immersion periods. A complete shift (from immersion to emersion periods) and a significant decrease in mobility and consequently its engineer potential, due to sewage contamination, lead to a 3-4 fold decrease in the amount of sediment disturbed. Sewage contamination, primary producers' abundance and environmental conditions may have influenced the gastropods survival, growth and its ecosystem engineering potential. - Terebralia palustris high ecosystem engineering potential in constructed mangrove wetlands.

  4. Master-slave manipulator

    International Nuclear Information System (INIS)

    Haaker, L.W.; Jelatis, D.G.

    1981-01-01

    A remote control master-slave manipulator for performing work on the opposite side of a barrier wall, is described. The manipulator consists of a rotatable horizontal support adapted to extend through the wall and two longitudinally extensible arms, a master and a slave, pivotally connected one to each end of the support. (U.K.)

  5. In Praise of Manipulation

    NARCIS (Netherlands)

    Dowding, Keith; Van Hees, Martin

    Many theorists believe that the manipulation of voting procedures is a serious problem. Accordingly, much of social choice theory examines the conditions under which strategy-proofness can be ensured, and what kind of procedures do a better job of preventing manipulation. This article argues that

  6. Cell manipulation in microfluidics

    International Nuclear Information System (INIS)

    Yun, Hoyoung; Kim, Kisoo; Lee, Won Gu

    2013-01-01

    Recent advances in the lab-on-a-chip field in association with nano/microfluidics have been made for new applications and functionalities to the fields of molecular biology, genetic analysis and proteomics, enabling the expansion of the cell biology field. Specifically, microfluidics has provided promising tools for enhancing cell biological research, since it has the ability to precisely control the cellular environment, to easily mimic heterogeneous cellular environment by multiplexing, and to analyze sub-cellular information by high-contents screening assays at the single-cell level. Various cell manipulation techniques in microfluidics have been developed in accordance with specific objectives and applications. In this review, we examine the latest achievements of cell manipulation techniques in microfluidics by categorizing externally applied forces for manipulation: (i) optical, (ii) magnetic, (iii) electrical, (iv) mechanical and (v) other manipulations. We furthermore focus on history where the manipulation techniques originate and also discuss future perspectives with key examples where available. (topical review)

  7. Manipulator comparative testing program

    International Nuclear Information System (INIS)

    Draper, J.V.; Handel, S.J.; Sundstrom, E.; Herndon, J.N.; Fujita, Y.; Maeda, M.

    1986-01-01

    The Manipulator Comparative Testing Program examined differences among manipulator systems from the United States and Japan. The manipulator systems included the Meidensha BILARM 83A, the Model M-2 of Central Research Laboratories Division of Sargent Industries (CRL), and the GCA Corporation PaR Systems Model 6000. The site of testing was the Remote Operations Maintenance Demonstration (ROMD) facility, operated by the Fuel Recycle Division in the Consolidated Fuel Reprocessing Program at the Oak Ridge National Laboratory (ORNL). In all stages of testing, operators using the CRL Model M-2 manipulator had consistently lower times to completion and error rates than they did using other machines. Performance was second best with the Meidensha BILARM 83A in master-slave mode. Performance with the BILARM in switchbox mode and the PaR 6000 manipulator was approximately equivalent in terms of criteria recorded in testing. These data show no impact of force reflection on task performance

  8. Non-use Economic Values for Little-Known Aquatic Species at Risk: Comparing Choice Experiment Results from Surveys Focused on Species, Guilds, and Ecosystems

    Science.gov (United States)

    Rudd, Murray A.; Andres, Sheri; Kilfoil, Mary

    2016-09-01

    Accounting for non-market economic values of biological diversity is important to fully assess the benefits of environmental policies and regulations. This study used three choice experiments (species-, guild-, and ecosystem-based surveys) in parallel to quantify non-use values for little-known aquatic species at risk in southern Ontario. Mean willingness-to-pay (WTP) ranged from 9.45 to 21.41 per listing status increment under Canada's Species at Risk Act for both named and unnamed little-known species. Given the broad range of valuable ecosystem services likely to accrue to residents from substantial increases in water quality and the rehabilitation of coastal wetlands, the difference in WTP between species- and ecosystem-based surveys seemed implausibly small. It appeared that naming species—the `iconization' of species in two of the three surveys—had an important effect on WTP. The results suggest that reasonable annual household-level WTP values for little-known aquatic species may be 10 to 25 per species or 10 to 20 per listing status increment. The results highlighted the utility of using parallel surveys to triangulate on non-use economic values for little-known species at risk.

  9. Computer control of a multi-link manipulator

    International Nuclear Information System (INIS)

    Holt, J.E.; Thiruarooran, C.

    1988-01-01

    The Central Electricity Generating Board has a requirement for a manipulator which can deploy to its work location around obstacles. A multilink manipulator has been designed for this purpose. A computer control system designed to ease manipulator operation is described. Using the control program, the manipulator may be deployed using just 2 joysticks. Experience in the use of the program with an inspection manipulator at Sizewell 'A' Nuclear Power Station is discussed. When used to control a manipulator of 9 hydraulically actuated degrees of freedom, a control accuracy of about 1.5% of full extension has been achieved. (author)

  10. Genetic diversity enhances the resistance of a seagrass ecosystem to disturbance

    OpenAIRE

    Hughes, A. R.; Stachowicz, John J

    2004-01-01

    Motivated by recent global reductions in biodiversity, empirical and theoretical research suggests that more species-rich systems exhibit enhanced productivity, nutrient cycling, or resistance to disturbance or invasion relative to systems with fewer species. In contrast, few data are available to assess the potential ecosystem-level importance of genetic diversity within species known to play a major functional role. Using a manipulative field experiment, we show that increasing genotypic di...

  11. A Choice Experiment for the Estimation of the Economic Value of the River Ecosystem: Management Policies for Sustaining NATURA (2000) species and the Coastal Environment

    OpenAIRE

    Phoebe Koundouri; Riccardo Scarpa; Mavra Stithou

    2013-01-01

    The valuation method of Choice Experiments (CEs) is often used for the economic valuation of natural areas with several nonmarket features that are either degraded or under-degradation. This method can be used to obtain estimates of Willingness-to-Pay (WTP) for the sustainability of several features of natural ecosystems. In particular, the CE method is a survey-based nonmarket valuation technique which can be used to estimate the total economic value of an environmental good in the form of a...

  12. Effects of Aluminium in Forest. Results of a pilot experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mulder, J; Wit, H de; Nygaard, P H

    1996-01-01

    This conference paper deals with an Norwegian pilot project which started in 1995 and finishing early 1999, investigates the solubility and phyto-toxicity of aluminium (Al) in mature forest ecosystems. The project consists of three major parts, including field manipulation study of Norwegian spruce stands, laboratory experiments and modelling Al chemistry in the root zone. 15 refs.

  13. Stereoscopically Observing Manipulative Actions.

    Science.gov (United States)

    Ferri, S; Pauwels, K; Rizzolatti, G; Orban, G A

    2016-08-01

    The purpose of this study was to investigate the contribution of stereopsis to the processing of observed manipulative actions. To this end, we first combined the factors "stimulus type" (action, static control, and dynamic control), "stereopsis" (present, absent) and "viewpoint" (frontal, lateral) into a single design. Four sites in premotor, retro-insular (2) and parietal cortex operated specifically when actions were viewed stereoscopically and frontally. A second experiment clarified that the stereo-action-specific regions were driven by actions moving out of the frontoparallel plane, an effect amplified by frontal viewing in premotor cortex. Analysis of single voxels and their discriminatory power showed that the representation of action in the stereo-action-specific areas was more accurate when stereopsis was active. Further analyses showed that the 4 stereo-action-specific sites form a closed network converging onto the premotor node, which connects to parietal and occipitotemporal regions outside the network. Several of the specific sites are known to process vestibular signals, suggesting that the network combines observed actions in peripersonal space with gravitational signals. These findings have wider implications for the function of premotor cortex and the role of stereopsis in human behavior. © The Author 2016. Published by Oxford University Press.

  14. Dimensions of ecosystem management: a system approach to policy formulation.

    Science.gov (United States)

    A.B. Carey

    1998-01-01

    For the past sixty years, ecologists have been arguing about what an ecosystem is, and the debate continues (Blew 1996; Lenz and Haber 1996). Ecosystem management, however, is an entirely human process that entails not only manipulating and protecting ecosystems but also making private and public goals operational within a larger social environment of public needs,...

  15. Manipulation, salience, and nudges.

    Science.gov (United States)

    Noggle, Robert

    2018-03-01

    Cass Sunstein and Richard Thaler recommend helping people make better decisions by employing 'nudges', which they define as noncoercive methods of influencing choice for the better. Not surprisingly, healthcare practitioners and public policy professionals have become interested in whether nudges might be a promising method of improving health-related behaviors without resorting to heavy-handed methods such as coercion, deception, or government regulation. Many nudges seem unobjectionable as they merely improve the quality and quantity available for the decision-maker. However, other nudges influence decision-making in ways that do not involve providing more and better information. Nudges of this sort raise concerns about manipulation. This paper will focus on noninformational nudges that operate by changing the salience of various options. It will survey two approaches to understanding manipulation, one which sees manipulation as a kind of pressure, and one that sees it as a kind of trickery. On the pressure view, salience nudges do not appear to be manipulative. However, on the trickery view (which the author favors), salience nudges will be manipulative if they increase the salience so that it is disproportionate to that fact's true relevance and importance for the decision at hand. By contrast, salience nudges will not be manipulative if they merely highlight some fact that is true and important for the decision at hand. The paper concludes by providing examples of both manipulative and nonmanipulative salience nudges. © 2017 John Wiley & Sons Ltd.

  16. Fungal symbiosis and precipitation alter traits and dune building by the ecosystem engineer, Ammophila breviligulata.

    Science.gov (United States)

    Emery, Sarah M; Bell-Dereske, Lukas; Rudgers, Jennifer A

    2015-04-01

    Ecosystem engineer species influence their community and ecosystem by creating or altering the physical structure of habitats. The function of ecosystem engineers is variable and can depend on both abiotic and biotic factors. Here we make use of a primary successional system to evaluate the direct and interactive effects of climate change (precipitation) and fungal endophyte symbiosis on population traits and ecosystem function of the ecosystem engineering grass species, Ammophila breviligulata. We manipulated endophyte presence in A. breviligulata in combination with rain-out shelters and rainfall additions in a factorial field experiment established in 2010 on Lake Michigan sand dunes. We monitored plant traits, survival, growth, and sexual reproduction of A. breviligulata from 2010-2013, and quantified ecosystem engineering as the sand accumulation rate. Presence of the endophyte in A. breviligulata increased vegetative growth by up to 19%, and reduced sexual reproduction by up to 46% across all precipitation treatments. Precipitation was a less significant factor than endophyte colonization for A. breviligulata growth. Reduced precipitation increased average leaf number per tiller but had no other effects on plant traits. Changes in A. breviligulata traits corresponded to increases in sand accumulation in plots with the endophyte as well as in plots with reduced precipitation. Sand accumulation is a key ecosystem function in these primary successional habitats, and so microbial symbiosis in this ecosystem engineer could lead to direct effects on the value of these dune habitats for humans.

  17. Control of a flexible bracing manipulator: Integration of current research work to realize the bracing manipulator

    Science.gov (United States)

    Kwon, Dong-Soo

    1991-01-01

    All research results about flexible manipulator control were integrated to show a control scenario of a bracing manipulator. First, dynamic analysis of a flexible manipulator was done for modeling. Second, from the dynamic model, the inverse dynamic equation was derived, and the time domain inverse dynamic method was proposed for the calculation of the feedforward torque and the desired flexible coordinate trajectories. Third, a tracking controller was designed by combining the inverse dynamic feedforward control with the joint feedback control. The control scheme was applied to the tip position control of a single link flexible manipulator for zero and non-zero initial condition cases. Finally, the contact control scheme was added to the position tracking control. A control scenario of a bracing manipulator is provided and evaluated through simulation and experiment on a single link flexible manipulator.

  18. Manipulators for production and research

    International Nuclear Information System (INIS)

    Munro, Ian

    1987-01-01

    The development of caves or cells and master-slave manipulators to handle radioactive materials is discussed. Some of the most recent advances are described. A manipulator arm, a master-slave manipulator and a servomanipulator mounted on a manipulator are illustrated. Future developments are discussed - these include resolved tip control for the manipulator. (UK)

  19. Powered manipulator control arm

    International Nuclear Information System (INIS)

    Le Mouee, Theodore; Vertut, Jean; Marchal, Paul; Germon, J.C.; Petit, Michel

    1975-01-01

    A remote operated control arm for powered manipulators is described. It includes an assembly allowing several movements with position sensors for each movement. The number of possible arm movements equals the number of possible manipulator movements. The control systems may be interrupted as required. One part of the arm is fitted with a system to lock it with respect to another part of the arm without affecting the other movements, so long as the positions of the manipulator and the arm have not been brought into complete coincidence. With this system the locking can be ended when complete concordance is achieved [fr

  20. The direct manipulation shell

    International Nuclear Information System (INIS)

    Allen, M.E.; Christiansen, M.

    1992-01-01

    Accelerator controls systems provide parameter display pages which allow the operator to monitor and manipulate selected control points in the system. Display pages are generally implemented as either hand-crafted, purpose-built programs; or by using a specialized display page layout tool. These two methods of display page development exhibit the classic trade-off between functionality vs. ease of implementation. In the Direct Manipulation Shell we approach the process of developing a display page in a manifestly object-oriented manner. This is done by providing a general framework for interactively instantiating and manipulating display objects. (author)

  1. Shifting the Arctic Carbon Balance: Effects of a Long-Term Fertilization Experiment and Anomalously Warm Temperatures on Net Ecosystem Exchange in the Alaskan Tundra

    Science.gov (United States)

    Ludwig, S.; Natali, S.; Rastetter, E. B.; Shaver, G. R.; Graham, L. M.; Jastrow, J. D.

    2017-12-01

    The arctic is warming at an accelerated rate relative to the globe. Among the predicted consequences of warming temperatures in the arctic are increased gross primary productivity (GPP), ecosystem respiration (ER), and nutrient availability. The net effect of these changes on the carbon (C) cycle and resulting C balance and feedback to climate change remain unclear. Historically the Arctic has been a C sink, but evidence from recent years suggests some regions in the Arctic are becoming C sources. To predict the role of the Arctic in global C cycling, the mechanisms affecting arctic C balances need to be better resolved. We measured net ecosystem exchange (NEE) in a long-term, multi-level, fertilization experiment at Toolik Lake, AK during an anomalously warm summer. We modeled NEE, ER, and GPP using a Bayesian network model. The best-fit model included Q10 temperature functions and linear fertilization functions for both ER and GPP. ER was more strongly affected by temperature and GPP was driven more by fertilization level. As a result, fertilization increased the C sink capacity, but only at moderate and low temperatures. At high temperatures (>28 °C) the NEE modeled for the highest level of fertilization was not significantly different from zero. In contrast, at ambient nutrient levels modeled NEE was significantly below zero (net uptake) until 35 °C, when it becomes neutral. Regardless of the level of fertilization, NEE never decreased with warming. Temperature in low ranges (5-15°C) had no net effect on NEE, whereas NEE began to increase exponentially with temperature after a threshold of 15°C until becoming a net source to the atmosphere at 37°C. Our results indicate that the C sink strength of tundra ecosystems can be increased with small increases in nutrient availability, but that large increase in nutrient availability can switch tundra ecosystems into C sources under warm conditions. Warming temperatures in tundra ecosystems will only decrease C

  2. Habitat structure mediates biodiversity effects on ecosystem properties.

    Science.gov (United States)

    Godbold, J A; Bulling, M T; Solan, M

    2011-08-22

    Much of what we know about the role of biodiversity in mediating ecosystem processes and function stems from manipulative experiments, which have largely been performed in isolated, homogeneous environments that do not incorporate habitat structure or allow natural community dynamics to develop. Here, we use a range of habitat configurations in a model marine benthic system to investigate the effects of species composition, resource heterogeneity and patch connectivity on ecosystem properties at both the patch (bioturbation intensity) and multi-patch (nutrient concentration) scale. We show that allowing fauna to move and preferentially select patches alters local species composition and density distributions, which has negative effects on ecosystem processes (bioturbation intensity) at the patch scale, but overall positive effects on ecosystem functioning (nutrient concentration) at the multi-patch scale. Our findings provide important evidence that community dynamics alter in response to localized resource heterogeneity and that these small-scale variations in habitat structure influence species contributions to ecosystem properties at larger scales. We conclude that habitat complexity forms an important buffer against disturbance and that contemporary estimates of the level of biodiversity required for maintaining future multi-functional systems may need to be revised.

  3. Geometric control of manipulators

    International Nuclear Information System (INIS)

    Thiruarooran, C.

    1996-01-01

    Resolved motion control enables the end effector to be moved as a rigid body in space without having to work out manually the joint combinations needed. Since a rigid body in space has three independent translational and three independent rotational movements, a manipulator with at least six joints can be controlled in this way. Normally the manipulator has more than six joints providing an infinite number of ways of moving the tip in the desired direction and this redundancy can be exploited in a variety of ways. Resolved motion tests performed on a hydraulically operated heavy duty manipulator at the Dungeness nuclear power plant are described. The results have shown that manipulators with as many as ten joints can be controlled under resolved tip motion and the areas which are critical to the performance of this type of control have been identified. (UK)

  4. MATHEMATICAL MODEL MANIPULATOR ROBOTS

    Directory of Open Access Journals (Sweden)

    O. N. Krakhmalev

    2015-12-01

    Full Text Available A mathematical model to describe the dynamics of manipulator robots. Mathematical model are the implementation of the method based on the Lagrange equation and using the transformation matrices of elastic coordinates. Mathematical model make it possible to determine the elastic deviations of manipulator robots from programmed motion trajectories caused by elastic deformations in hinges, which are taken into account in directions of change of the corresponding generalized coordinates. Mathematical model is approximated and makes it possible to determine small elastic quasi-static deviations and elastic vibrations. The results of modeling the dynamics by model are compared to the example of a two-link manipulator system. The considered model can be used when performing investigations of the mathematical accuracy of the manipulator robots.

  5. Surgical manipulation of mammalian embryos in vitro.

    Science.gov (United States)

    Naruse, I; Keino, H; Taniguchi, M

    1997-04-01

    Whole-embryo culture systems are useful in the fields of not only embryology but also teratology, toxicology, pharmacology, and physiology. Of the many advantages of whole-embryo culture, we focus here on the surgical manipulation of mammalian embryos. Whole-embryo culture allows us to manipulate mammalian embryos, similarly to fish, amphibian and avian embryos. Many surgical experiments have been performed in mammalian embryos in vitro. Such surgical manipulation alters the destiny of morphogenesis of the embryos and can answer many questions concerning developmental issues. As an example of surgical manipulation using whole-embryo culture systems, one of our experiments is described. Microsurgical electrocauterization of the deep preaxial mesodermal programmed cell death zone (fpp) in the footplate prevented the manifestation of polydactyly in genetic polydactyly mouse embryos (Pdn/Pdn), in which fpp was abolished.

  6. Controls on Ecosystem and Root Respiration in an Alaskan Peatland

    Science.gov (United States)

    McConnell, N. A.; McGuire, A. D.; Harden, J. W.; Kane, E. S.; Turetsky, M. R.

    2010-12-01

    Boreal ecosystems cover 14% of the vegetated surface on earth and account for 25-30% of the world’s soil carbon (C), mainly due to large carbon stocks in deep peat and frozen soil layers. While peatlands have served as historical sinks of carbon, global climate change may trigger re-release of C to the atmosphere and may turn these ecosystems into net C sources. Rates of C release from a peatland are determined by regional climate and local biotic and abiotic factors such as vegetation cover, thaw depth, and peat thickness. Soil CO2 fluxes are driven by both autotrophic (plant) respiration and heterotrophic (microbial) respiration. Thus, changes in plant and microbial activity in the soil will impact CO2 emissions from peatlands. In this study, we explored environmental and vegetation controls on ecosystem respiration and root respiration in a variety of wetland sites. The study was conducted at the Alaskan Peatland Experiment (APEX; www.uoguelph.ca/APEX) sites in the Bonanza Creek Experimental Forest located 35 km southwest of Fairbanks Alaska. We measured ecosystem respiration, root respiration, and monitored a suite of environmental variables along a vegetation and soil moisture gradient including a black spruce stand with permafrost, a shrubby site with permafrost, a tussock grass site, and a herbaceous open rich fen. Within the rich fen, we have been conducting water table manipulations including a control, lowered, and raised water table treatment. In each of our sites, we measured total ecosystem respiration using static chambers and root respiration by harvesting roots from the uppermost 20 cm and placing them in a root cuvette to obtain a root flux. Ecosystem respiration (ER) on a μmol/m2/sec basis varied across sites. Water table was a significant predictor of ER at the lowered manipulation site and temperature was a strong predictor at the control site in the rich fen. Water table and temperature were both significant predictors of ER at the raised

  7. Entrepreneurial Ecosystems

    NARCIS (Netherlands)

    Stam, F.C.; Spigel, Ben

    2016-01-01

    This paper reviews and discusses the emergent entrepreneurial ecosystem approach. Entrepreneurial ecosystems are defined as a set of interdependent actors and factors coordinated in such a way that they enable productive entrepreneurship within a particular territory. The purpose of this paper is to

  8. Effects of a large scale nitrogen and phosphorous fertilization on the ecosystem functioning of a Mediterranean tree-grass ecosystem

    Science.gov (United States)

    Migliavacca, Mirco; El Madany, Tarek; Perez-Priego, Oscar; Carrara, Arnaud; Hammer, Tiana; Henkel, Kathin; Kolle, Olaf; Luo, Yunpeng; Moreno, Gerardo; Morris, Kendalynn; Nair, Richard; Schrumpf, Marion; Wutzler, Thomas; Reichstein, Markus

    2017-04-01

    Recent studies have shown how human induced N/P imbalances affect essential ecosystem processes, and might be particularly important in water-limited ecosystems. In this contribution we will present results from an ecosystem scale nutrient manipulation experiment on a Mediterranean tree-grass ecosystem (Majadas del Tietar, Spain). Specifically, we will show how ecosystem functioning (e.g. light use efficiency, water use efficiency - WUE, albedo) changes as consequence of N and NP fertilization. A cluster of eddy covariance (EC) flux towers has been set up beside a long-term EC site (Control site) to measured high temporal resolution C and water fluxes between the ecosystem and the atmosphere. The sites were selected in a way to have similar pre-treatment conditions. Two out of three EC footprint areas (18 Ha) were fertilized with N and NP at the beginning of 2015 and 2016. To interpret the variations in C and water fluxes measured with the EC systems we monitored spatial and temporal variations in phenology, plant traits, species richness, and tree transpiration by using sap-flow meters, digital repeat photography, as well as soil sampling. The results show a consistent increase ( 15% compared to the Control site) in net ecosystem production (NEP) observed both in the N and the NP treatments. An increase of evapotranspiration (ET) of about 15% and 10% is observed in the N and NP site, respectively, indicating an increase of WUE in the NP treatment. The partitioning of the NEP into its gross components, the gross primary production (GPP) and the total ecosystem respiration (TER), show that the fertilization stimulated more GPP rather than TER, increasing therefore the capability of the ecosystem to act as carbon sink. The effects of fertilization are pronounced in spring and autumn and negligible in summer. This indicates that grass reacted much more than trees to N and NP addition. An increase of greenness and also an earlier green-up of grass in the N and NP sites

  9. Coordinated approaches to quantify long-term ecosystem dynamics in response to global change

    DEFF Research Database (Denmark)

    Liu, Y.; Melillo, J.; Niu, S.

    2011-01-01

    a coordinated approach that combines long-term, large-scale global change experiments with process studies and modeling. Long-term global change manipulative experiments, especially in high-priority ecosystems such as tropical forests and high-latitude regions, are essential to maximize information gain......Many serious ecosystem consequences of climate change will take decades or even centuries to emerge. Long-term ecological responses to global change are strongly regulated by slow processes, such as changes in species composition, carbon dynamics in soil and by long-lived plants, and accumulation...... to be the most effective strategy to gain the best information on long-term ecosystem dynamics in response to global change....

  10. Influence of contrast morphogenetic features of urban constructed soils on the functioning of Moscow green lawn urban ecosystems: analysis based on the field model experiment

    Science.gov (United States)

    Epikhina, Anna; Vizirskaya, Mariya; Mazirov, Ilya; Vasenev, Vyacheslav; Vasenev, Ivan; Valentini, Riccardo

    2014-05-01

    Green lawns are the key element of the urban environment. They occupy a considerable part of the city area and locate in different urban functional zones. Urban constructed soils under green lawns have a unique spatial variability in chemical and morphogenetic features. So far, there is lack of information on the influence of morphogenetic features of urban soils on the functioning of the green lawn ecosystems especially in Moscow - the biggest megalopolis in Europe. Urban lawns perform a number of principal functions including both aesthetic and environmental. The role of the green lawn ecosystems in global carbon cycle is one of their main environmental functions. It is traditionally assessed through carbon stocks and fluxes in the basic ecosystem components. So far, such a data for the urban lawn ecosystems of the Moscow megapolis is lacking. In addition to environmental functions, green lawns perform an important ornamental role, which is also a critical criterion of their optimal functioning. Considering the variability of driving factors, influencing green lawns in urban environment, we carry out the model experiment in order to analyze "pure" effect of soil morphogenetic features. The current study aimed to analyze the influence of contrast morphogenetic features of urban constructed soils on the environmental and aesthetic functions of lawn ecosystems in Moscow megapolis basing in the model experiment. We carry out the model experiment located at the experimental field of the Russian State Agrarian University. Special transparent containers developed for the experiment, provided an option to observe soil morphogenetic features dynamics, including the depth and material of the organic transformation. At the same soil body inside the containers was united with the outside environment through the system of holes in the bottom and walls. The set of urban constructed soils includ four contrast types of the top soil (turf (T), turf-sand (TSa), turf-soil (TSo) and

  11. Astronomical Ecosystems

    Science.gov (United States)

    Neuenschwander, D. E.; Finkenbinder, L. R.

    2004-05-01

    Just as quetzals and jaguars require specific ecological habitats to survive, so too must planets occupy a tightly constrained astronomical habitat to support life as we know it. With this theme in mind we relate the transferable features of our elementary astronomy course, "The Astronomical Basis of Life on Earth." Over the last five years, in a team-taught course that features a spring break field trip to Costa Rica, we have introduced astronomy through "astronomical ecosystems," emphasizing astronomical constraints on the prospects for life on Earth. Life requires energy, chemical elements, and long timescales, and we emphasize how cosmological, astrophysical, and geological realities, through stabilities and catastrophes, create and eliminate niches for biological life. The linkage between astronomy and biology gets immediate and personal: for example, studies in solar energy production are followed by hikes in the forest to examine the light-gathering strategies of photosynthetic organisms; a lesson on tides is conducted while standing up to our necks in one on a Pacific beach. Further linkages between astronomy and the human timescale concerns of biological diversity, cultural diversity, and environmental sustainability are natural and direct. Our experience of teaching "astronomy as habitat" strongly influences our "Astronomy 101" course in Oklahoma as well. This "inverted astrobiology" seems to transform our student's outlook, from the universe being something "out there" into something "we're in!" We thank the SNU Science Alumni support group "The Catalysts," and the SNU Quetzal Education and Research Center, San Gerardo de Dota, Costa Rica, for their support.

  12. Biological soil crusts (biocrusts) as a model system in community, landscape and ecosystem ecology

    Science.gov (United States)

    Bowker, Matthew A.; Maestre, Fernando T.; Eldridge, David; Belnap, Jayne; Castillo-Monroy, Andrea; Escolar, Cristina; Soliveres, Santiago

    2014-01-01

    Model systems have had a profound influence on the development of ecological theory and general principles. Compared to alternatives, the most effective models share some combination of the following characteristics: simpler, smaller, faster, general, idiosyncratic or manipulable. We argue that biological soil crusts (biocrusts) have unique combinations of these features that should be more widely exploited in community, landscape and ecosystem ecology. In community ecology, biocrusts are elucidating the importance of biodiversity and spatial pattern for maintaining ecosystem multifunctionality due to their manipulability in experiments. Due to idiosyncrasies in their modes of facilitation and competition, biocrusts have led to new models on the interplay between environmental stress and biotic interactions and on the maintenance of biodiversity by competitive processes. Biocrusts are perhaps one of the best examples of micro-landscapes—real landscapes that are small in size. Although they exhibit varying patch heterogeneity, aggregation, connectivity and fragmentation, like macro-landscapes, they are also compatible with well-replicated experiments (unlike macro-landscapes). In ecosystem ecology, a number of studies are imposing small-scale, low cost manipulations of global change or state factors in biocrust micro-landscapes. The versatility of biocrusts to inform such disparate lines of inquiry suggests that they are an especially useful model system that can enable researchers to see ecological principles more clearly and quickly.

  13. Predicting richness effects on ecosystem function in natural communities

    DEFF Research Database (Denmark)

    Dangles, Olivier; Crespo-Pérez, Verónica; Andino, Patricio

    2011-01-01

    rates in the field, although water discharge may also play a role locally. We also examined the relative contribution of the three most abundant shredders on decomposition rates by manipulating shredder richness and community composition in a field experiment. Transgressive overyielding was detected....... Despite the increased complexity of experimental and theoretical studies on the biodiversity-ecosystem functioning (B-EF) relationship, a major challenge is to demonstrate whether the observed importance of biodiversity in controlled experimental systems also persists in nature. Due...... to their structural simplicity and their low levels of human impacts, extreme species-poor ecosystems may provide new insights into B-EF relationships in natural systems. We address this issue using shredder invertebrate communities and organic matter decomposition rates in 24 high-altitude (3200-3900 m) Neotropical...

  14. Richness, biomass, and nutrient content of a wetland macrophyte community affect soil nitrogen cycling in a diversity-ecosystem functioning experiment

    Science.gov (United States)

    Korol, Alicia R.; Ahn, Changwoo; Noe, Gregory

    2016-01-01

    The development of soil nitrogen (N) cycling in created wetlands promotes the maturation of multiple biogeochemical cycles necessary for ecosystem functioning. This development proceeds from gradual changes in soil physicochemical properties and influential characteristics of the plant community, such as competitive behavior, phenology, productivity, and nutrient composition. In the context of a 2-year diversity experiment in freshwater mesocosms (0, 1, 2, 3, or 4 richness levels), we assessed the direct and indirect impacts of three plant community characteristics – species richness, total biomass, and tissue N concentration – on three processes in the soil N cycle – soil net ammonification, net nitrification, and denitrification potentials. Species richness had a positive effect on net ammonification potential (NAP) through higher redox potentials and likely faster microbial respiration. All NAP rates were negative, however, due to immobilization and high rates of ammonium removal. Net nitrification was inhibited at higher species richness without mediation from the measured soil properties. Higher species richness also inhibited denitrification potential through increased redox potential and decreased nitrification. Both lower biomass and/or higher tissue ratios of carbon to nitrogen, characteristics indicative of the two annual plants, were shown to have stimulatory effects on all three soil N processes. The two mediating physicochemical links between the young macrophyte community and microbial N processes were soil redox potential and temperature. Our results suggest that early-successional annual plant communities play an important role in the development of ecosystem N multifunctionality in newly created wetland soils.

  15. Complex Effects of Ecosystem Engineer Loss on Benthic Ecosystem Response to Detrital Macroalgae.

    Directory of Open Access Journals (Sweden)

    Francesca Rossi

    Full Text Available Ecosystem engineers change abiotic conditions, community assembly and ecosystem functioning. Consequently, their loss may modify thresholds of ecosystem response to disturbance and undermine ecosystem stability. This study investigates how loss of the bioturbating lugworm Arenicola marina modifies the response to macroalgal detrital enrichment of sediment biogeochemical properties, microphytobenthos and macrofauna assemblages. A field manipulative experiment was done on an intertidal sandflat (Oosterschelde estuary, The Netherlands. Lugworms were deliberately excluded from 1× m sediment plots and different amounts of detrital Ulva (0, 200 or 600 g Wet Weight were added twice. Sediment biogeochemistry changes were evaluated through benthic respiration, sediment organic carbon content and porewater inorganic carbon as well as detrital macroalgae remaining in the sediment one month after enrichment. Microalgal biomass and macrofauna composition were measured at the same time. Macroalgal carbon mineralization and transfer to the benthic consumers were also investigated during decomposition at low enrichment level (200 g WW. The interaction between lugworm exclusion and detrital enrichment did not modify sediment organic carbon or benthic respiration. Weak but significant changes were instead found for porewater inorganic carbon and microalgal biomass. Lugworm exclusion caused an increase of porewater carbon and a decrease of microalgal biomass, while detrital enrichment drove these values back to values typical of lugworm-dominated sediments. Lugworm exclusion also decreased the amount of macroalgae remaining into the sediment and accelerated detrital carbon mineralization and CO2 release to the water column. Eventually, the interaction between lugworm exclusion and detrital enrichment affected macrofauna abundance and diversity, which collapsed at high level of enrichment only when the lugworms were present. This study reveals that in nature the

  16. Complex Effects of Ecosystem Engineer Loss on Benthic Ecosystem Response to Detrital Macroalgae.

    Science.gov (United States)

    Rossi, Francesca; Gribsholt, Britta; Gazeau, Frederic; Di Santo, Valentina; Middelburg, Jack J

    2013-01-01

    Ecosystem engineers change abiotic conditions, community assembly and ecosystem functioning. Consequently, their loss may modify thresholds of ecosystem response to disturbance and undermine ecosystem stability. This study investigates how loss of the bioturbating lugworm Arenicola marina modifies the response to macroalgal detrital enrichment of sediment biogeochemical properties, microphytobenthos and macrofauna assemblages. A field manipulative experiment was done on an intertidal sandflat (Oosterschelde estuary, The Netherlands). Lugworms were deliberately excluded from 1× m sediment plots and different amounts of detrital Ulva (0, 200 or 600 g Wet Weight) were added twice. Sediment biogeochemistry changes were evaluated through benthic respiration, sediment organic carbon content and porewater inorganic carbon as well as detrital macroalgae remaining in the sediment one month after enrichment. Microalgal biomass and macrofauna composition were measured at the same time. Macroalgal carbon mineralization and transfer to the benthic consumers were also investigated during decomposition at low enrichment level (200 g WW). The interaction between lugworm exclusion and detrital enrichment did not modify sediment organic carbon or benthic respiration. Weak but significant changes were instead found for porewater inorganic carbon and microalgal biomass. Lugworm exclusion caused an increase of porewater carbon and a decrease of microalgal biomass, while detrital enrichment drove these values back to values typical of lugworm-dominated sediments. Lugworm exclusion also decreased the amount of macroalgae remaining into the sediment and accelerated detrital carbon mineralization and CO2 release to the water column. Eventually, the interaction between lugworm exclusion and detrital enrichment affected macrofauna abundance and diversity, which collapsed at high level of enrichment only when the lugworms were present. This study reveals that in nature the role of this

  17. Latitudinal gradients in ecosystem engineering by oysters vary across habitats.

    Science.gov (United States)

    McAfee, Dominic; Cole, Victoria J; Bishop, Melanie J

    2016-04-01

    Ecological theory predicts that positive interactions among organisms will increase across gradients of increasing abiotic stress or consumer pressure. This theory has been supported by empirical studies examining the magnitude of ecosystem engineering across environmental gradients and between habitat settings at local scale. Predictions that habitat setting, by modifying both biotic and abiotic factors, will determine large-scale gradients in ecosystem engineering have not been tested, however. A combination of manipulative experiments and field surveys assessed whether along the east Australian coastline: (1) facilitation of invertebrates by the oyster Saccostrea glomerata increased across a latitudinal gradient in temperature; and (2) the magnitude of this effect varied between intertidal rocky shores and mangrove forests. It was expected that on rocky shores, where oysters are the primary ecosystem engineer, they would play a greater role in ameliorating latitudinal gradients in temperature than in mangroves, where they are a secondary ecosystem engineer living under the mangrove canopy. On rocky shores, the enhancement of invertebrate abundance in oysters as compared to bare microhabitat decreased with latitude, as the maximum temperatures experienced by intertidal organisms diminished. By contrast, in mangrove forests, where the mangrove canopy resulted in maximum temperatures that were cooler and of greater humidity than on rocky shores, we found no evidence of latitudinal gradients of oyster effects on invertebrate abundance. Contrary to predictions, the magnitude by which oysters enhanced biodiversity was in many instances similar between mangroves and rocky shores. Whether habitat-context modifies patterns of spatial variation in the effects of ecosystem engineers on community structure will depend, in part, on the extent to which the environmental amelioration provided by an ecosystem engineer replicates that of other co-occurring ecosystem engineers.

  18. Ecosystem thermodynamics

    International Nuclear Information System (INIS)

    Gomez Palacio, German Rau

    1998-01-01

    Ecology is no more a descriptive and self-sufficient science. Many viewpoints are needed simultaneously to give a full coverage of such complex systems: ecosystems. These viewpoints come from physics, chemistry, and nuclear physics, without a new far from equilibrium thermodynamics and without new mathematical tools such as catastrophe theory, fractal theory, cybernetics and network theory, the development of ecosystem science would never have reached the point of today. Some ideas are presented about the importance that concept such as energy, entropy, exergy information and none equilibrium have in the analysis of processes taking place in ecosystems

  19. Atomic and molecular manipulation

    CERN Document Server

    Mayne, Andrew J

    2011-01-01

    Work with individual atoms and molecules aims to demonstrate that miniaturized electronic, optical, magnetic, and mechanical devices can operate ultimately even at the level of a single atom or molecule. As such, atomic and molecular manipulation has played an emblematic role in the development of the field of nanoscience. New methods based on the use of the scanning tunnelling microscope (STM) have been developed to characterize and manipulate all the degrees of freedom of individual atoms and molecules with an unprecedented precision. In the meantime, new concepts have emerged to design molecules and substrates having specific optical, mechanical and electronic functions, thus opening the way to the fabrication of real nano-machines. Manipulation of individual atoms and molecules has also opened up completely new areas of research and knowledge, raising fundamental questions of "Optics at the atomic scale", "Mechanics at the atomic scale", Electronics at the atomic scale", "Quantum physics at the atomic sca...

  20. Balanced articulated manipulator

    International Nuclear Information System (INIS)

    Francois, Daniel; Germond, J.-C.; Marchal, Paul; Vertut, Jean.

    1976-01-01

    The description is given of a manipulator of the type comprising a master arm and a slave arm, capable of working in a containment restricted by a wall fitted with an aperture to introduce the slave arm into the containment. According to the invention this manipulator is permanently balanced irrespective of its distortions when it is secured to the wall of the containment in which it is desired to work. The entire manipulator is also balanced when being set up and when moved outside the containment, in relation to a supporting axle. This result is achieved in a simplified manner by giving homothetic shapes to the various component parts of the slave and master arms, the master arm having at least one balancing weight [fr

  1. Stainless steel decontamination manipulators

    International Nuclear Information System (INIS)

    Sullivan, R.J.

    1986-01-01

    Three, large-volume coverage manipulator systems were designed and built for the Defense Water Processing Facility at the Savannah River Laboratory. These stainless steel systems will be used for high-pressure spray decontamination of waste containers and large process equipment modules. Each system has a manipulator arm, folding boom, and vertical drive and guide structure. Handling capacity is 45 kg, horizontal reach is 4.6 m with a 180-deg swing motion, and the vertical travel is 6 m. The system is remotely removable and replaceable in modules using an overhead crane and an impact wrench. The manipulator arm has seven motions: Shoulder rotation and pivot, elbow pivot, wrist pivot and rotation, and grip open-close. All motions are variable speed and are slip-clutch protected to prevent overloading from external forces (collisions)

  2. Managing collaboration in the nanoManipulator

    DEFF Research Database (Denmark)

    Hudson, Thomas C.; Heiser, Aron T.; Sonnenwald, Diane H.

    2003-01-01

    We designed, developed, deployed, and evaluated the Collaborative nanoManipulator (CnM), a system supporting remote collaboration between users of the nanoManipulator interface to atomic force microscopes. To be accepted by users, the shared nanoManipulator application had to have the same high...... level of interactivity as the single user system and the application had to support a user's ability to interleave working privately and working collaboratively. This paper briefly describes the entire collaboration system, but focuses on the shared nanoManipulator application. Based on our experience...... developing the CnM, we present: a method of analyzing applications to characterize the requirements for sharing data between collaborating sites, examples of data structures that support collaboration, and guidelines for selecting appropriate synchronization and concurrency control schemes....

  3. Data manipulation with R

    CERN Document Server

    Abedin, Jaynal

    2014-01-01

    This book is a step-by step, example-oriented tutorial that will show both intermediate and advanced users how data manipulation is facilitated smoothly using R.This book is aimed at intermediate to advanced level users of R who want to perform data manipulation with R, and those who want to clean and aggregate data effectively. Readers are expected to have at least an introductory knowledge of R and some basic administration work in R, such as installing packages and calling them when required.

  4. Urban ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Duvigneaud, P

    1974-01-01

    The author considers the town as an ecosystem. He examines its various subdivisions (climate, soil, structure, human and non-human communities, etc.) for which he chooses examples with particular reference to the city of Brussels.

  5. Manipulation of BDNF signaling modifies the experience-dependent plasticity induced by pure tone exposure during the critical period in the primary auditory cortex.

    Science.gov (United States)

    Anomal, Renata; de Villers-Sidani, Etienne; Merzenich, Michael M; Panizzutti, Rogerio

    2013-01-01

    Sensory experience powerfully shapes cortical sensory representations during an early developmental "critical period" of plasticity. In the rat primary auditory cortex (A1), the experience-dependent plasticity is exemplified by significant, long-lasting distortions in frequency representation after mere exposure to repetitive frequencies during the second week of life. In the visual system, the normal unfolding of critical period plasticity is strongly dependent on the elaboration of brain-derived neurotrophic factor (BDNF), which promotes the establishment of inhibition. Here, we tested the hypothesis that BDNF signaling plays a role in the experience-dependent plasticity induced by pure tone exposure during the critical period in the primary auditory cortex. Elvax resin implants filled with either a blocking antibody against BDNF or the BDNF protein were placed on the A1 of rat pups throughout the critical period window. These pups were then exposed to 7 kHz pure tone for 7 consecutive days and their frequency representations were mapped. BDNF blockade completely prevented the shaping of cortical tuning by experience and resulted in poor overall frequency tuning in A1. By contrast, BDNF infusion on the developing A1 amplified the effect of 7 kHz tone exposure compared to control. These results indicate that BDNF signaling participates in the experience-dependent plasticity induced by pure tone exposure during the critical period in A1.

  6. Manipulation of BDNF signaling modifies the experience-dependent plasticity induced by pure tone exposure during the critical period in the primary auditory cortex.

    Directory of Open Access Journals (Sweden)

    Renata Anomal

    Full Text Available Sensory experience powerfully shapes cortical sensory representations during an early developmental "critical period" of plasticity. In the rat primary auditory cortex (A1, the experience-dependent plasticity is exemplified by significant, long-lasting distortions in frequency representation after mere exposure to repetitive frequencies during the second week of life. In the visual system, the normal unfolding of critical period plasticity is strongly dependent on the elaboration of brain-derived neurotrophic factor (BDNF, which promotes the establishment of inhibition. Here, we tested the hypothesis that BDNF signaling plays a role in the experience-dependent plasticity induced by pure tone exposure during the critical period in the primary auditory cortex. Elvax resin implants filled with either a blocking antibody against BDNF or the BDNF protein were placed on the A1 of rat pups throughout the critical period window. These pups were then exposed to 7 kHz pure tone for 7 consecutive days and their frequency representations were mapped. BDNF blockade completely prevented the shaping of cortical tuning by experience and resulted in poor overall frequency tuning in A1. By contrast, BDNF infusion on the developing A1 amplified the effect of 7 kHz tone exposure compared to control. These results indicate that BDNF signaling participates in the experience-dependent plasticity induced by pure tone exposure during the critical period in A1.

  7. Particle manipulation techniques in AEgIS

    Energy Technology Data Exchange (ETDEWEB)

    Canali, C., E-mail: canali@ge.infn.it; Carraro, C.; Di Noto, L.; Krasnicky, D.; Lagomarsino, V.; Testera, G.; Zavatarelli, S. [Istituto Nazionale Fisica Nucleare Sez. Genova (Italy)

    2011-07-15

    The AEgIS experiment (http://aegis.web.cern.chhttp://aegis.web.cern.ch) will measure the gravitational acceleration g of antihydrogen. Once performed this could be the first direct test of the gravitational interaction between matter and antimatter. In the AEgIS experiment a beam of antihydrogen will travel horizontally along a path of about 1 m trough a moire deflectometer followed by a position sensitive detector. The g value will be obtained measuring the vertical displacement of the annihilation patterns. Before producing the beam, several tasks have to be performed mainly involving positron and electron plasma manipulation and particles cooling in Malmberg-Penning traps. The AEgIS experiment is currently under construction at CERN, meanwhile several tests involving particle manipulation and particle cooling are in progress. In this report some experimental results involving diocotron manipulation of plasma will be presented.

  8. Rising tides, cumulative impacts and cascading changes to estuarine ecosystem functions.

    Science.gov (United States)

    O'Meara, Theresa A; Hillman, Jenny R; Thrush, Simon F

    2017-08-31

    In coastal ecosystems, climate change affects multiple environmental factors, yet most predictive models are based on simple cause-and-effect relationships. Multiple stressor scenarios are difficult to predict because they can create a ripple effect through networked ecosystem functions. Estuarine ecosystem function relies on an interconnected network of physical and biological processes. Estuarine habitats play critical roles in service provision and represent global hotspots for organic matter processing, nutrient cycling and primary production. Within these systems, we predicted functional changes in the impacts of land-based stressors, mediated by changing light climate and sediment permeability. Our in-situ field experiment manipulated sea level, nutrient supply, and mud content. We used these stressors to determine how interacting environmental stressors influence ecosystem function and compared results with data collected along elevation gradients to substitute space for time. We show non-linear, multi-stressor effects deconstruct networks governing ecosystem function. Sea level rise altered nutrient processing and impacted broader estuarine services ameliorating nutrient and sediment pollution. Our experiment demonstrates how the relationships between nutrient processing and biological/physical controls degrade with environmental stress. Our results emphasise the importance of moving beyond simple physically-forced relationships to assess consequences of climate change in the context of ecosystem interactions and multiple stressors.

  9. MANIPULATING CONSUMERS THROUGH ADVERTISING

    Directory of Open Access Journals (Sweden)

    Nicoleta -Andreea Neacşu

    2012-12-01

    Full Text Available Marketing communication has evolved steadily in the direction of increasing complexity and increasing volume of funds needed to run their own actions. More than ever, consumers are exposed to an overwhelming variety of sources and communication tehniques, the information received being numerous, diverse and polyvalent. The desire to make more efficient the marketing communication activity urges the broadcasters to encode messages, to use effective means of propagation in order to obtain a high degree of control on receptors and to influence the consumption attitudes. Between the means used for this purpose, manipulation tehniques are well known. This paper highlights the main conclusions drawn as a result of a quantitative marketing research on the adult population from Braşov in order to identify the attitudes and opinions of consumers from Braşov regarding the manipulation techniques used by commercial practices and advertising.The results of the research have shown that 82% of the respondents buy products in promotional offers, and 18% choose not to buy these products and 61% of the respondents consider that they have not been manipulated not even once, while only 39% believe that they have been manipulated at least once through advertising or commercial practices. Advertisements on TV have a strong influence on consumers, 81% of the respondents considering that at least once they have bought a product because of a TV commercial.

  10. Microrobots to Manipulate Cells

    DEFF Research Database (Denmark)

    Glückstad, Jesper

    At DTU Fotonik we developed and harnessed the new and emerging research area of so-called Light Robotics including the 3D-printed micro-tools coined Wave-guided Optical Waveguides that can be real-time laser-manipulated in a 3D-volume with six-degrees-of-freedom. To be exploring the full potentia...

  11. Automated visual attention manipulation

    NARCIS (Netherlands)

    Bosse, T.; Lambalgen, R. van; Maanen, P.P. van; Treur, J.

    2009-01-01

    In this paper a system for visual attention manipulation is introduced and formally described. This system is part of the design of a software agent that supports naval crew in her task to compile a tactical picture of the situation in the field. A case study is described in hich the system is used

  12. Data manipulation with R

    CERN Document Server

    Abedin, Jaynal

    2015-01-01

    This book is for all those who wish to learn about data manipulation from scratch and excel at aggregating data effectively. It is expected that you have basic knowledge of R and have previously done some basic administration work with R.

  13. Manipulating Combinatorial Structures.

    Science.gov (United States)

    Labelle, Gilbert

    This set of transparencies shows how the manipulation of combinatorial structures in the context of modern combinatorics can easily lead to interesting teaching and learning activities at every level of education from elementary school to university. The transparencies describe: (1) the importance and relations of combinatorics to science and…

  14. IL4 gene polymorphism and previous malaria experiences manipulate anti-Plasmodium falciparum antibody isotype profiles in complicated and uncomplicated malaria

    Directory of Open Access Journals (Sweden)

    Kalambaheti Thareerat

    2009-12-01

    Full Text Available Abstract Background The IL4-590 gene polymorphism has been shown to be associated with elevated levels of anti-Plasmodium falciparum IgG antibodies and parasite intensity in the malaria protected Fulani of West Africa. This study aimed to investigate the possible impact of IL4-590C/T polymorphism on anti-P. falciparum IgG subclasses and IgE antibodies levels and the alteration of malaria severity in complicated and uncomplicated malaria patients with or without previous malaria experiences. Methods Anti-P.falciparum IgG subclasses and IgE antibodies in plasma of complicated and uncomplicated malaria patients with or without previous malaria experiences were analysed using ELISA. IL4-590 polymorphisms were genotyped using RFLP-PCR. Statistical analyses of the IgG subclass levels were done by Oneway ANOVA. Genotype differences were tested by Chi-squared test. Results The IL4-590T allele was significantly associated with anti-P. falciparum IgG3 antibody levels in patients with complicated (P = 0.031, but not with uncomplicated malaria (P = 0.622. Complicated malaria patients with previous malaria experiences carrying IL4-590TT genotype had significantly lower levels of anti-P. falciparum IgG3 (P = 0.0156, while uncomplicated malaria patients with previous malaria experiences carrying the same genotype had significantly higher levels (P = 0.0206 compared to their IL4-590 counterparts. The different anti-P. falciparum IgG1 and IgG3 levels among IL4 genotypes were observed. Complicated malaria patients with previous malaria experiences tended to have lower IgG3 levels in individuals carrying TT when compared to CT genotypes (P = 0.075. In contrast, complicated malaria patients without previous malaria experiences carrying CC genotype had significantly higher anti-P. falciparum IgG1 than those carrying either CT or TT genotypes (P = 0.004, P = 0.002, respectively. Conclusion The results suggest that IL4-590C or T alleles participated differently in the

  15. Strategic ecosystems of Colombia

    International Nuclear Information System (INIS)

    Marquez Calle German

    2002-01-01

    The author relates the ecosystems in Colombia, he makes a relationship between ecosystems and population, utility of the ecosystems, transformation of the ecosystems and poverty and he shows a methodology of identification of strategic ecosystems

  16. Payment for ecosystem services

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Oddershede, Jakob Stoktoft; Pedersen, Anders Branth

    Research question: Northern Europe experiences an increasingly wet climate, leading to more frequent and severe fluvial flood events. Ecosystem-based Adaptation (EbA) is becoming recognised as a valuable yet under-utilised means to alleviating negative effects of a changing climate. This however,...

  17. Spatial pattern enhances ecosystem functioning in an African savanna.

    Science.gov (United States)

    Pringle, Robert M; Doak, Daniel F; Brody, Alison K; Jocqué, Rudy; Palmer, Todd M

    2010-05-25

    The finding that regular spatial patterns can emerge in nature from local interactions between organisms has prompted a search for the ecological importance of these patterns. Theoretical models have predicted that patterning may have positive emergent effects on fundamental ecosystem functions, such as productivity. We provide empirical support for this prediction. In dryland ecosystems, termite mounds are often hotspots of plant growth (primary productivity). Using detailed observations and manipulative experiments in an African savanna, we show that these mounds are also local hotspots of animal abundance (secondary and tertiary productivity): insect abundance and biomass decreased with distance from the nearest termite mound, as did the abundance, biomass, and reproductive output of insect-eating predators. Null-model analyses indicated that at the landscape scale, the evenly spaced distribution of termite mounds produced dramatically greater abundance, biomass, and reproductive output of consumers across trophic levels than would be obtained in landscapes with randomly distributed mounds. These emergent properties of spatial pattern arose because the average distance from an arbitrarily chosen point to the nearest feature in a landscape is minimized in landscapes where the features are hyper-dispersed (i.e., uniformly spaced). This suggests that the linkage between patterning and ecosystem functioning will be common to systems spanning the range of human management intensities. The centrality of spatial pattern to system-wide biomass accumulation underscores the need to conserve pattern-generating organisms and mechanisms, and to incorporate landscape patterning in efforts to restore degraded habitats and maximize the delivery of ecosystem services.

  18. Whole-ecosystem experimental manipulations of tropical forests

    Czech Academy of Sciences Publication Activity Database

    Fayle, Tom Maurice; Turner, E. C.; Basset, Yves; Ewers, R. M.; Reynolds, G.; Novotný, Vojtěch

    2015-01-01

    Roč. 30, č. 6 (2015), s. 334-346 ISSN 0169-5347 R&D Projects: GA ČR GA14-32302S; GA ČR(CZ) GA14-04258S; GA ČR GB14-36098G Grant - others:Euroepan Social Fund(CZ) CZ.1.07/2.3.00/20.0064 Institutional support: RVO:60077344 Keywords : tropical forests Subject RIV: EH - Ecology, Behaviour Impact factor: 16.735, year: 2015 http://www.cell.com/trends/ecology-evolution/pdf/S0169-5347(15)00069-5.pdf

  19. Model Simulations of a Mesocosm Experiment Investigating the Response of a Low Nutrient Low Chlorophyll (LNLC Marine Ecosystem to Atmospheric Deposition Events

    Directory of Open Access Journals (Sweden)

    Kostas P. Tsiaras

    2017-05-01

    Full Text Available Atmospheric deposition of nitrogen and phosphorus represents an important source of nutrients, enhancing the marine productivity in oligotrophic areas, e.g., the Mediterranean. A comprehensive biogeochemical model (ERSEM was setup and customized to simulate a mesocosm experiment, where dissolved inorganic nitrogen and phosphorus by means of atmospheric dust (single addition/SA and repetitive addition/RA in three successive doses was added in controlled tanks and compared with a control (blank, all with Cretan Sea (Eastern Mediterranean water. Observations on almost all components of the pelagic ecosystem in a ten-day period allowed investigating the effect of atmospheric deposition and the pathways of the added nutrients. The model was able to reasonably capture the observed variability of different ecosystem components and reproduce the main features of the experiment. An enhancement of primary production and phytoplankton biomass with added nutrients was simulated, in agreement with observations. A significant increase of bacterial production was also reproduced, while the model underestimated the observed increase and variability in bacterial biomass, but this deviation could be partly removed considering a lower carbon conversion factor from cell abundance data. A slightly stronger overall response was simulated with the single dust addition, compared to the repetitive that showed a few days delay. The simulated carbon pathways indicated that nutrient additions did not modify the microbial food web structure, but just increased its trophic status. Changes in model assumptions and parameter set that were necessary to reproduce the observed variability in the mesocosm experiment were discussed through a series of sensitivity simulations. Bacterial production was assumed to be mostly affected by the in situ produced labile organic matter, while it was further stimulated by the addition of inorganic nutrients, adopting a function of external

  20. A universal microscope manipulator

    Directory of Open Access Journals (Sweden)

    Peter S. Boyadzhiev

    2012-03-01

    Full Text Available A modified and improved model of a mechanical manipulator for observation of pinned and mounted insects is described. This device allows movement of the observed object around three perpendicular axes in the field of vision at all magnifications of stereomicroscopes. The main improvement of this new model is positioning of the guiding knobs for rotating around two of the axes next to each other, allowing faster and easier manipulation of the studied object. Thus, one of the main advantages of this device is the possibility to rotate the specimen without the need to refocus. The device enables easily reaching a precession deviation in the intersection point of axes up to 0.5 mm in the process of assembling.

  1. Microradiographic microsphere manipulator

    International Nuclear Information System (INIS)

    Singleton, R.M.

    1980-01-01

    A method and apparatus are provided for radiographic characterization of small hollow spherical members (microspheres), constructed of either optically transparent or opaque materials. The apparatus involves a microsphere manipulator which holds a batch of microspheres between two parallel thin plastic films for contact microradiographic characterization or projection microradiography thereof. One plastic film is translated to relative to and parallel to the other to roll the microspheres through any desired angle to allow different views of the microspheres

  2. Manipulation of quantum evolution

    Science.gov (United States)

    Cabera, David Jose Fernandez; Mielnik, Bogdan

    1994-01-01

    The free evolution of a non-relativistic charged particle is manipulated using time-dependent magnetic fields. It is shown that the application of a programmed sequence of magnetic pulses can invert the free evolution process, forcing an arbitrary wave packet to 'go back in time' to recover its past shape. The possibility of more general operations upon the Schrodinger wave packet is discussed.

  3. Manipulating atoms with photons

    International Nuclear Information System (INIS)

    Cohen-Tannoudji, C.N.

    1998-01-01

    The article is a translation of the lecture delivered on the occasion of the 1997 Nobel Prize awarding ceremony. The physical mechanisms which allow manipulating of neutral atoms with laser photons are described. A remark is also made concerning several possible applications of ultra-cool atoms and streams of future research. The article is completed by Prof. Cohen-Tannoudji's autobiography. (Z.J.)

  4. Protozoa manipulation by ultrasound

    Directory of Open Access Journals (Sweden)

    Yancy Milena Porras Rodríguez

    2004-01-01

    Full Text Available Microorganism manipulation, considered as controlled motion and positioning, is one of the most important activities in microbiology and medicine. To achieve this goal there are some techniques such as those which and optical forces, among others. These techniques are usually sophisticated, and some of them can induce irreversible alterations on the microorganisms which prevents their use in another tests. Thus, there is justified the study of technological alternatives to manipulate microorganisms in an easy and cost-effective way. This work shows the interaction between protozoa and air microbubbles when they are under the influence of an ultrasonic field of 5.8 mW. At the microbubbles resonant frequencies, microorganisms were attracted toward the bubbles' frontier remaining there while the ultrasonic field was applied. Once the ultrasound disappears, protozoa recover their freedom of movement. The observed effects could be used as the actuation principle of devices capable to trap, hold and release microorganisms of high mobility without any apparent damage. Microbubbles are generated by electrolysis which take place on the surface of an electrode array, while the ultrasound is originated by means of a piezoelectric transducer. As microorganisms there were employed those present in stagnated water, and were observed through an stereomicroscope. Key words: manipulator; protozoa; ultrasonic; transducer; piezoelectric.

  5. Pose Space Surface Manipulation

    Directory of Open Access Journals (Sweden)

    Yusuke Yoshiyasu

    2012-01-01

    Full Text Available Example-based mesh deformation techniques produce natural and realistic shapes by learning the space of deformations from examples. However, skeleton-based methods cannot manipulate a global mesh structure naturally, whereas the mesh-based approaches based on a translational control do not allow the user to edit a local mesh structure intuitively. This paper presents an example-driven mesh editing framework that achieves both global and local pose manipulations. The proposed system is built with a surface deformation method based on a two-step linear optimization technique and achieves direct manipulations of a model surface using translational and rotational controls. With the translational control, the user can create a model in natural poses easily. The rotational control can adjust the local pose intuitively by bending and twisting. We encode example deformations with a rotation-invariant mesh representation which handles large rotations in examples. To incorporate example deformations, we infer a pose from the handle translations/rotations and perform pose space interpolation, thereby avoiding involved nonlinear optimization. With the two-step linear approach combined with the proposed multiresolution deformation method, we can edit models at interactive rates without losing important deformation effects such as muscle bulging.

  6. Heterotrophic respiration in drained tropical peat is greatly affected by temperature—a passive ecosystem cooling experiment

    International Nuclear Information System (INIS)

    Jauhiainen, Jyrki; Kerojoki, Otto; Vasander, Harri; Silvennoinen, Hanna; Limin, Suwido

    2014-01-01

    Vast areas of deforested tropical peatlands do not receive noteworthy shading by vegetation, which increases the amount of solar radiation reaching the peat surface. Peat temperature dynamics and heterotrophic carbon dioxide (CO 2 ), nitrous oxide (N 2 O) and methane (CH 4 ) fluxes were monitored under four shading conditions, i.e. unshaded, 28%, 51% and 90% shading at experiment sites established on reclaimed fallow agricultural- and degraded sites in Central Kalimantan, Indonesia. Groundwater tables on the sites were at about 50 cm depth, the sites were maintained vegetation free and root ingrowth to gas flux monitoring locations was prevented. Half of the four shading areas received NPK-fertilization 50 kg ha −1 for each of N, P and K during the experiment and the other half was unfertilized. Increases in shading created a lasting decrease in peat temperatures, and decreased diurnal temperature fluctuations, in comparison to less shaded plots. The largest peat temperature difference in the topmost 50 cm peat profile was between the unshaded and 90% shaded surface, where the average temperatures at 5 cm depth differed up to 3.7 °C, and diurnal temperatures at 5 cm depth varied up to 4.2 °C in the unshaded and 0.4 °C in the 90% shaded conditions. Highest impacts on the heterotrophic CO 2 fluxes caused by the treatments were on agricultural land, where 90% shading from the full exposure resulted in a 33% lower CO 2 emission average on the unfertilized plots and a 66% lower emission average on the fertilized plots. Correlation between peat temperature and CO 2 flux suggested an approximately 8% (unfertilized) and 25% (fertilized) emissions change for each 1 °C temperature change at 5 cm depth on the agricultural land. CO 2 flux responses to the treatments remained low on degraded peatland. Fertilized conditions negatively correlated with N 2 O efflux with increases in temperature, suggesting a 12–36% lower efflux for each 1 °C increase in peat temperature

  7. Variability of the carbonate chemistry in a shallow, seagrass-dominated ecosystem: implications for ocean acidification experiments

    Science.gov (United States)

    Challener, Roberta; Robbins, Lisa L.; Mcclintock, James B.

    2016-01-01

    Open ocean observations have shown that increasing levels of anthropogenically derived atmospheric CO2 are causing acidification of the world's oceans. Yet little is known about coastal acidification and studies are just beginning to characterise the carbonate chemistry of shallow, nearshore zones where many ecologically and economically important organisms occur. We characterised the carbonate chemistry of seawater within an area dominated by seagrass beds (Saint Joseph Bay, Florida) to determine the extent of variation in pH and pCO2 over monthly and daily timescales. Distinct diel and seasonal fluctuations were observed at daily and monthly timescales respectively, indicating the influence of photosynthetic and respiratory processes on the local carbonate chemistry. Over the course of a year, the range in monthly values of pH (7.36-8.28), aragonite saturation state (0.65-5.63), and calculated pCO2 (195-2537 μatm) were significant. When sampled on a daily basis the range in pH (7.70-8.06), aragonite saturation state (1.86-3.85), and calculated pCO2 (379-1019 μatm) also exhibited significant range and indicated variation between timescales. The results of this study have significant implications for the design of ocean acidification experiments where nearshore species are utilised and indicate that coastal species are experiencing far greater fluctuations in carbonate chemistry than previously thought.

  8. Machine Learnig for Robotic Manipulation in cluttered environments

    OpenAIRE

    Alet Puig, Ferran

    2016-01-01

    In this thesis we focus on designing the planner for MIT s entry in the Amazon Picking Challenge, a robotic competition aiming at pushing the frontiers of manipulation until robots can substitute human pickers in warehouses. Given a set of manipulation primitives (such as grasping, suction, scooping, placing or pushing) we designed a system capable of learning a planner from a set of manipulation experiments. After learning, given any configuration of objects, the planner can come up with the...

  9. Designer ecosystems

    NARCIS (Netherlands)

    Awasthi, Ashutosh; Singh, Kripal; O'Grady, Audrey; Courtney, Ronan; Kalra, Alok; Singh, Rana Pratap; Cerda Bolinches, Artemio; Steinberger, Yosef; Patra, D.D.

    2016-01-01

    Increase in human population is accelerating the rate of land use change, biodiversity loss and habitat degradation, triggering a serious threat to life supporting ecosystem services. Existing strategies for biological conservation remain insufficient to achieve a sustainable human-nature

  10. Perception and manipulation of game control

    NARCIS (Netherlands)

    Plass - Oude Bos, D.; van de Laar, B.L.A.; Reuderink, B.; Poel, Mannes; Nijholt, Antinus; Reidsma, Dennis; Choi, Insook; Bargar, Robin

    Brain-computer interfaces do not provide perfect recognition of user input, for similar reasons as natural input modalities. How well can users assess the amount of control they have, and how much control do they need? We describe an experiment where we manipulated the control users had in a

  11. Early Childhood Math: Make It Manipulative!

    Science.gov (United States)

    Stone, Janet I.

    1987-01-01

    Maintains that early childhood teachers should provide young children with creative, stimulating, and manipulative (hands-on) experiences rather than workbook pages in early mathematics programs. Presents reasons and corresponding counterpositions for using workbooks and suggests sample activities which teachers can use to make mathematics more…

  12. Using large-scale flow experiments to rehabilitate Colorado River ecosystem function in Grand Canyon: Basis for an adaptive climate-resilient strategy: Chapter 17

    Science.gov (United States)

    Melis, Theodore S.; Pine, William E.; Korman, Josh; Yard, Michael D.; Jain, Shaleen; Pulwarty, Roger S.; Miller, Kathleen; Hamlet, Alan F.; Kenney, Douglas S.; Redmond, Kelly T.

    2016-01-01

    Adaptive management of Glen Canyon Dam is improving downstream resources of the Colorado River in Glen Canyon National Recreation Area and Grand Canyon National Park. The Glen Canyon Dam Adaptive Management Program (AMP), a federal advisory committee of 25 members with diverse special interests tasked to advise the U.S. Department of the Interior), was established in 1997 in response to the 1992 Grand Canyon Protection Act. Adaptive management assumes that ecosystem responses to management policies are inherently complex and unpredictable, but that understanding and management can be improved through monitoring. Best known for its high-flow experiments intended to benefit physical and biological resources by simulating one aspect of pre-dam conditions—floods, the AMP promotes collaboration among tribal, recreation, hydropower, environmental, water and other natural resource management interests. Monitoring has shown that high flow experiments move limited new tributary sand inputs below the dam from the bottom of the Colorado River to shorelines; rebuilding eroded sandbars that support camping areas and other natural and cultural resources. Spring-timed high flows have also been shown to stimulate aquatic productivity by disturbing the river bed below the dam in Glen Canyon. Understanding about how nonnative tailwater rainbow trout (Oncorhynchus mykiss), and downstream endangered humpback chub (Gila cypha) respond to dam operations has also increased, but this learning has mostly posed “surprise” adaptation opportunities to managers. Since reoperation of the dam to Modified Low Fluctuating Flows in 1996, rainbow trout now benefit from more stable daily flows and high spring releases, but possibly at a risk to humpback chub and other native fishes downstream. In contrast, humpback chub have so far proven robust to all flows, and native fish have increased under the combination of warmer river temperatures associated with reduced storage in Lake Powell, and a

  13. Comprehensive ecosystem model-data synthesis using multiple data sets at two temperate forest free-air CO2 enrichment experiments: Model performance at ambient CO2 concentration

    Science.gov (United States)

    Walker, Anthony P.; Hanson, Paul J.; De Kauwe, Martin G.; Medlyn, Belinda E.; Zaehle, Sönke; Asao, Shinichi; Dietze, Michael; Hickler, Thomas; Huntingford, Chris; Iversen, Colleen M.; Jain, Atul; Lomas, Mark; Luo, Yiqi; McCarthy, Heather; Parton, William J.; Prentice, I. Colin; Thornton, Peter E.; Wang, Shusen; Wang, Ying-Ping; Warlind, David; Weng, Ensheng; Warren, Jeffrey M.; Woodward, F. Ian; Oren, Ram; Norby, Richard J.

    2014-05-01

    Free-air CO2 enrichment (FACE) experiments provide a remarkable wealth of data which can be used to evaluate and improve terrestrial ecosystem models (TEMs). In the FACE model-data synthesis project, 11 TEMs were applied to two decadelong FACE experiments in temperate forests of the southeastern U.S.—the evergreen Duke Forest and the deciduous Oak Ridge Forest. In this baseline paper, we demonstrate our approach to model-data synthesis by evaluating the models' ability to reproduce observed net primary productivity (NPP), transpiration, and leaf area index (LAI) in ambient CO2 treatments. Model outputs were compared against observations using a range of goodness-of-fit statistics. Many models simulated annual NPP and transpiration within observed uncertainty. We demonstrate, however, that high goodness-of-fit values do not necessarily indicate a successful model, because simulation accuracy may be achieved through compensating biases in component variables. For example, transpiration accuracy was sometimes achieved with compensating biases in leaf area index and transpiration per unit leaf area. Our approach to model-data synthesis therefore goes beyond goodness-of-fit to investigate the success of alternative representations of component processes. Here we demonstrate this approach by comparing competing model hypotheses determining peak LAI. Of three alternative hypotheses—(1) optimization to maximize carbon export, (2) increasing specific leaf area with canopy depth, and (3) the pipe model—the pipe model produced peak LAI closest to the observations. This example illustrates how data sets from intensive field experiments such as FACE can be used to reduce model uncertainty despite compensating biases by evaluating individual model assumptions.

  14. Ecosystem productivity is associated with bacterial phylogenetic distance in surface marine waters.

    Science.gov (United States)

    Galand, Pierre E; Salter, Ian; Kalenitchenko, Dimitri

    2015-12-01

    Understanding the link between community diversity and ecosystem function is a fundamental aspect of ecology. Systematic losses in biodiversity are widely acknowledged but the impact this may exert on ecosystem functioning remains ambiguous. There is growing evidence of a positive relationship between species richness and ecosystem productivity for terrestrial macro-organisms, but similar links for marine micro-organisms, which help drive global climate, are unclear. Community manipulation experiments show both positive and negative relationships for microbes. These previous studies rely, however, on artificial communities and any links between the full diversity of active bacterial communities in the environment, their phylogenetic relatedness and ecosystem function remain hitherto unexplored. Here, we test the hypothesis that productivity is associated with diversity in the metabolically active fraction of microbial communities. We show in natural assemblages of active bacteria that communities containing more distantly related members were associated with higher bacterial production. The positive phylogenetic diversity-productivity relationship was independent of community diversity calculated as the Shannon index. From our long-term (7-year) survey of surface marine bacterial communities, we also found that similarly, productive communities had greater phylogenetic similarity to each other, further suggesting that the traits of active bacteria are an important predictor of ecosystem productivity. Our findings demonstrate that the evolutionary history of the active fraction of a microbial community is critical for understanding their role in ecosystem functioning. © 2015 John Wiley & Sons Ltd.

  15. Using Manipulatives in Math Instruction.

    Science.gov (United States)

    Marzola, Eileen S.

    1987-01-01

    Guidelines for teachers to better use manipulatives in the teaching of mathematics to learning disabled learners are offered including a rationale for manipulatives, selection crteria, principles underlying productive use of manipulatives, and making the transition from the concrete to the symbolic. Suggested materials and distributors are listed.…

  16. Manipulating affective state influences conditioned appetitive responses.

    Science.gov (United States)

    Arnaudova, Inna; Krypotos, Angelos-Miltiadis; Effting, Marieke; Kindt, Merel; Beckers, Tom

    2017-10-06

    Affective states influence how individuals process information and behave. Some theories predict emotional congruency effects (e.g. preferential processing of negative information in negative affective states). Emotional congruency should theoretically obstruct the learning of reward associations (appetitive learning) and their ability to guide behaviour under negative mood. Two studies tested the effects of the induction of a negative affective state on appetitive Pavlovian learning, in which neutral stimuli were associated with chocolate (Experiment 1) or alcohol (Experiment 2) rewards. In both experiments, participants showed enhanced approach tendencies towards predictors of reward after a negative relative to a positive performance feedback manipulation. This increase was related to a reduction in positive affect in Experiment 1 only. No effects of the manipulation on conditioned reward expectancies, craving, or consumption were observed. Overall, our findings support the idea of counter-regulation, rather than emotional congruency effects. Negative affective states might therefore serve as a vulnerability factor for addiction, through increasing conditioned approach tendencies.

  17. Ecosystem functional response across precipitation extremes in a sagebrush steppe.

    Science.gov (United States)

    Tredennick, Andrew T; Kleinhesselink, Andrew R; Taylor, J Bret; Adler, Peter B

    2018-01-01

    Precipitation is predicted to become more variable in the western United States, meaning years of above and below average precipitation will become more common. Periods of extreme precipitation are major drivers of interannual variability in ecosystem functioning in water limited communities, but how ecosystems respond to these extremes over the long-term may shift with precipitation means and variances. Long-term changes in ecosystem functional response could reflect compensatory changes in species composition or species reaching physiological thresholds at extreme precipitation levels. We conducted a five year precipitation manipulation experiment in a sagebrush steppe ecosystem in Idaho, United States. We used drought and irrigation treatments (approximately 50% decrease/increase) to investigate whether ecosystem functional response remains consistent under sustained high or low precipitation. We recorded data on aboveground net primary productivity (ANPP), species abundance, and soil moisture. We fit a generalized linear mixed effects model to determine if the relationship between ANPP and soil moisture differed among treatments. We used nonmetric multidimensional scaling to quantify community composition over the five years. Ecosystem functional response, defined as the relationship between soil moisture and ANPP, was similar among irrigation and control treatments, but the drought treatment had a greater slope than the control treatment. However, all estimates for the effect of soil moisture on ANPP overlapped zero, indicating the relationship is weak and uncertain regardless of treatment. There was also large spatial variation in ANPP within-years, which contributes to the uncertainty of the soil moisture effect. Plant community composition was remarkably stable over the course of the experiment and did not differ among treatments. Despite some evidence that ecosystem functional response became more sensitive under sustained drought conditions, the response

  18. Burkholderia thailandensis: Genetic Manipulation.

    Science.gov (United States)

    Garcia, Erin C

    2017-05-16

    Burkholderia thailandensis is a Gram-negative bacterium endemic to Southeast Asian and northern Australian soils. It is non-pathogenic; therefore, it is commonly used as a model organism for the related human pathogens Burkholderia mallei and Burkholderia pseudomallei. B. thailandensis is relatively easily genetically manipulated and a variety of robust genetic tools can be used in this organism. This unit describes protocols for conjugation, natural transformation, mini-Tn7 insertion, and allelic exchange in B. thailandensis. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  19. Spatial manipulation with microfluidics

    Directory of Open Access Journals (Sweden)

    Benjamin eLin

    2015-04-01

    Full Text Available Biochemical gradients convey information through space, time, and concentration, and are ultimately capable of spatially resolving distinct cellular phenotypes, such as differentiation, proliferation, and migration. How these gradients develop, evolve, and function during development, homeostasis, and various disease states is a subject of intense interest across a variety of disciplines. Microfluidic technologies have become essential tools for investigating gradient sensing in vitro due to their ability to precisely manipulate fluids on demand in well controlled environments at cellular length scales. This minireview will highlight their utility for studying gradient sensing along with relevant applications to biology.

  20. A novel membrane inlet mass spectrometer method to measure ¹⁵NH4₄⁺ for isotope-enrichment experiments in aquatic ecosystems.

    Science.gov (United States)

    Yin, Guoyu; Hou, Lijun; Liu, Min; Liu, Zhanfei; Gardner, Wayne S

    2014-08-19

    Nitrogen (N) pollution in aquatic ecosystems has attracted much attention over the past decades, but the dynamics of this bioreactive element are difficult to measure in aquatic oxygen-transition environments. Nitrogen-transformation experiments often require measurement of (15)N-ammonium ((15)NH4(+)) ratios in small-volume (15)N-enriched samples. Published methods to determine N isotope ratios of dissolved ammonium require large samples and/or costly equipment and effort. We present a novel ("OX/MIMS") method to determine N isotope ratios for (15)NH4(+) in experimental waters previously enriched with (15)N compounds. Dissolved reduced (15)N (dominated by (15)NH4(+)) is oxidized with hypobromite iodine to nitrogen gas ((29)N2 and/or (30)N2) and analyzed by membrane inlet mass spectrometry (MIMS) to quantify (15)NH4(+) concentrations. The N isotope ratios, obtained by comparing the (15)NH4(+) to total ammonium (via autoanalyzer) concentrations, are compared to the ratios of prepared standards. The OX/MIMS method requires only small sample volumes of water (ca. 12 mL) or sediment slurries and is rapid, convenient, accurate, and precise (R(2) = 0.9994, p < 0.0001) over a range of salinities and (15)N/(14)N ratios. It can provide data needed to quantify rates of ammonium regeneration, potential ammonium uptake, and dissimilatory nitrate reduction to ammonium (DNRA). Isotope ratio results agreed closely (R = 0.998, P = 0.001) with those determined independently by isotope ratio mass spectrometry for DNRA measurements or by ammonium isotope retention time shift liquid chromatography for water-column N-cycling experiments. Application of OX/MIMS should simplify experimental approaches and improve understanding of N-cycling rates and fate in a variety of freshwater and marine environments.

  1. Drained coastal peatlands: A potential nitrogen source to marine ecosystems under prolonged drought and heavy storm events-A microcosm experiment.

    Science.gov (United States)

    Wang, Hongjun; Richardson, Curtis J; Ho, Mengchi; Flanagan, Neal

    2016-10-01

    Over the past several decades there has been a massive increase in coastal eutrophication, which is often caused by increased runoff input of nitrogen from landscape alterations. Peatlands, covering 3% of land area, have stored about 12-21% of global soil organic nitrogen (12-20Pg N) around rivers, lakes and coasts over millennia and are now often drained and farmed. Their huge nitrogen pools may be released by intensified climate driven hydrologic events-prolonged droughts followed by heavy storms-and later transported to marine ecosystems. In this study, we collected peat monoliths from drained, natural, and restored coastal peatlands in the Southeastern U.S., and conducted a microcosm experiment simulating coupled prolonged-drought and storm events to (1) test whether storms could trigger a pulse of nitrogen export from drought-stressed peatlands and (2) assess how differentially hydrologic managements through shifting plant communities affect nitrogen export by combining an experiment of nitrogen release from litter. During the drought phase, we observed a significant temporal variation in net nitrogen mineralization rate (NMR). NMR spiked in the third month and then decreased rapidly. This pattern indicates that drought duration significantly affects nitrogen mineralization in peat. NMR in the drained site reached up to 490±110kgha(-1)year(-1), about 5 times higher than in the restored site. After the 14-month drought phase, we simulated a heavy storm by bringing peat monoliths to saturation. In the discharge waters, concentrations of total dissolved nitrogen in the monoliths from the drained site (72.7±16.3mgL(-1)) was about ten times as high as from the restored site. Our results indicate that previously drained peatlands under prolonged drought are a potent source of nitrogen export. Moreover, drought-induced plant community shifts to herbaceous plants substantially raise nitrogen release with lasting effects by altering litter quality in peatlands

  2. Remote control manipulator

    Energy Technology Data Exchange (ETDEWEB)

    Sugawara, T

    1970-02-28

    A prior-art remote control manipulator comprises a horizontal suspension section, a master arm and a slave arm which are coupled to ends of the suspension section in a manner to pivotally move relative to the suspension section, and a connecting device which includes a tape and which joins both the arms. When the connecting device malfunctions, the slave arm can neither be extended nor contracted. Means to keep the tension of the tape is required which restricts the extension length of the slave arm. Further, the slave arm can be moved only in the axial direction. The invention described provides an improved remote control manipulator of the specified type. A moving device which moves the slave arm relative to the master arm without the intervention of the connecting device is mounted on a movable part of the slave arm, while pulleys which maintain the joining relationship of the connecting device are mounted on the movable part and fixed part of the slave arm. Owing to this construction, movement of the slave arm is assured despite troubles which may arise in the connecting device. In addition, no slack arises in the tape. By applying a similar construction to the horizontal suspension section, the suspension section can be stretched, and hence, the slave arm can be moved in a direction orthogonal to its axis.

  3. Biodiversity-ecosystem functioning relationships in long-term time series and palaeoecological records: deep sea as a test bed.

    Science.gov (United States)

    Yasuhara, Moriaki; Doi, Hideyuki; Wei, Chih-Lin; Danovaro, Roberto; Myhre, Sarah E

    2016-05-19

    The link between biodiversity and ecosystem functioning (BEF) over long temporal scales is poorly understood. Here, we investigate biological monitoring and palaeoecological records on decadal, centennial and millennial time scales from a BEF framework by using deep sea, soft-sediment environments as a test bed. Results generally show positive BEF relationships, in agreement with BEF studies based on present-day spatial analyses and short-term manipulative experiments. However, the deep-sea BEF relationship is much noisier across longer time scales compared with modern observational studies. We also demonstrate with palaeoecological time-series data that a larger species pool does not enhance ecosystem stability through time, whereas higher abundance as an indicator of higher ecosystem functioning may enhance ecosystem stability. These results suggest that BEF relationships are potentially time scale-dependent. Environmental impacts on biodiversity and ecosystem functioning may be much stronger than biodiversity impacts on ecosystem functioning at long, decadal-millennial, time scales. Longer time scale perspectives, including palaeoecological and ecosystem monitoring data, are critical for predicting future BEF relationships on a rapidly changing planet. © 2016 The Author(s).

  4. Synergy of extreme drought and shrub invasion reduce ecosystem functioning and resilience in water-limited climates

    Science.gov (United States)

    Caldeira, Maria C.; Lecomte, Xavier; David, Teresa S.; Pinto, Joaquim G.; Bugalho, Miguel N.; Werner, Christiane

    2015-10-01

    Extreme drought events and plant invasions are major drivers of global change that can critically affect ecosystem functioning and alter ecosystem-atmosphere exchange. Invaders are expanding worldwide and extreme drought events are projected to increase in frequency and intensity. However, very little is known on how these drivers may interact to affect the functioning and resilience of ecosystems to extreme events. Using a manipulative shrub removal experiment and the co-occurrence of an extreme drought event (2011/2012) in a Mediterranean woodland, we show that native shrub invasion and extreme drought synergistically reduced ecosystem transpiration and the resilience of key-stone oak tree species. Ecosystem transpiration was dominated by the water use of the invasive shrub Cistus ladanifer, which further increased after the extreme drought event. Meanwhile, the transpiration of key-stone tree species decreased, indicating a competitive advantage in favour of the invader. Our results suggest that in Mediterranean-type climates the invasion of water spending species and projected recurrent extreme drought events may synergistically cause critical drought tolerance thresholds of key-stone tree species to be surpassed, corroborating observed higher tree mortality in the invaded ecosystems. Ultimately, this may shift seasonally water limited ecosystems into less desirable alternative states dominated by water spending invasive shrubs.

  5. Agent Control for Reconfigurable Open Kinematic Chain Manipulators

    Directory of Open Access Journals (Sweden)

    Janez Sluga

    2013-10-01

    Full Text Available This paper presents a method for the autonomous control of differently structured open kinematic chains based on multi-agent system technology. The appropriate level of distributing local autonomy (agents to a manipulative structure is defined, which makes it possible to dynamically change the number, type and structure of manipulative components without modifying their behavioural logic. To achieve fast reconfigurable and scalable manipulative systems, a new multi-agent method is developed for controlling the manipulator kinematics. The new method enables independent manipulator structure from the control system because of its structural and system modularity. The proposed method consists of kinematic equations for use in an agent environment, agent motion-planning algorithms, evaluation functions, agent control logic and kinematic algorithms. The results of simulations and real-world experiments demonstrate the usefulness of the approach for different non-redundant and redundant manipulation structures.

  6. [Language Manipulation, Surrogacy, Altruism].

    Science.gov (United States)

    Serrano Ruiz-Calderón, José Miguel

    2017-01-01

    The Newspeak propitiates a change of the sense of the words and next to the double thinking forms the picture of totalitarianism described by Orwell in 1984. The purpose of the Newspeak is to make all other forms of thought impossible. In bioethics the Newspeak is applied, not because Bioethics is a new science but by the manipulative intention. The twentieth-century political language has, according to Orwell, the intention to remove the ″mental image ″ of what really happens. This is clear in the terms ″surrogacy ″. On the one hand, the mother is deprived of her child. On the other, there is no legal subrogation. As has been said the technique reduces a woman to the condition of a vessel. The excuse of gratuity does not change the exploitative relationship, since gratuitousness in the provision of women is not the altruism of all those involved in surrogacy.

  7. Media and manipulation

    Directory of Open Access Journals (Sweden)

    Kovačević Braco

    2013-01-01

    Full Text Available The role and importance of the media are huge, both in everyday life and in cultural, spiritual and political life of modern man. Their power in the sense of political shaping of people and shaping of public opinion is very distinctive. In the process of propaganda to influence public opinion, they use various manipulative procedures in order to accomplish certain interests and objectives. Through the media, politics realizes its economic, ideological, political and even military activities. The war in the former Yugoslavia and former Bosnia and Herzegovina was also waged through the media. This media war still is spreading the hate speech, thus still causing conflicts and disintegration processes in the Balkans.

  8. Interactive protein manipulation

    Energy Technology Data Exchange (ETDEWEB)

    SNCrivelli@lbl.gov

    2003-07-01

    We describe an interactive visualization and modeling program for the creation of protein structures ''from scratch''. The input to our program is an amino acid sequence -decoded from a gene- and a sequence of predicted secondary structure types for each amino acid-provided by external structure prediction programs. Our program can be used in the set-up phase of a protein structure prediction process; the structures created with it serve as input for a subsequent global internal energy minimization, or another method of protein structure prediction. Our program supports basic visualization methods for protein structures, interactive manipulation based on inverse kinematics, and visualization guides to aid a user in creating ''good'' initial structures.

  9. Interactive protein manipulation

    International Nuclear Information System (INIS)

    2003-01-01

    We describe an interactive visualization and modeling program for the creation of protein structures ''from scratch''. The input to our program is an amino acid sequence -decoded from a gene- and a sequence of predicted secondary structure types for each amino acid-provided by external structure prediction programs. Our program can be used in the set-up phase of a protein structure prediction process; the structures created with it serve as input for a subsequent global internal energy minimization, or another method of protein structure prediction. Our program supports basic visualization methods for protein structures, interactive manipulation based on inverse kinematics, and visualization guides to aid a user in creating ''good'' initial structures

  10. Characteristics of manipulative in mathematics laboratory

    Science.gov (United States)

    Istiandaru, A.; Istihapsari, V.; Prahmana, R. C. I.; Setyawan, F.; Hendroanto, A.

    2017-12-01

    A manipulative is a teaching aid designed such that students could understand mathematical concepts by manipulating it. This article aims to provide an insight to the characteristics of manipulatives produced in the mathematics laboratory of Universitas Ahmad Dahlan, Indonesia. A case study was conducted to observe the existing manipulatives produced during the latest three years and classified the manipulatives based on the characteristics found. There are four kinds of manipulatives: constructivism manipulative, virtual manipulative, informative manipulative, and game-based manipulative. Each kinds of manipulative has different characteristics and impact towards the mathematics learning.

  11. Manipulator Comparative Testing Program: Final report

    International Nuclear Information System (INIS)

    Draper, J.V.; Handel, S.J.; Sundstrom, E.; Herndon, J.N; Fujita, Y.; Maeda, M.

    1987-02-01

    The manipulator systems tested included the Meidensha BILARM 83A, the Central Research Laboratories Model M-2, and the GCA PaR Systems Model 6000. Six manipulator and control mode combinations were evaluated: (1) the BILARM in master/slave mode without force reflection, (2) the BILARM in master/slave mode with force reflection, (3) the Model M-2 in master/slave mode without force reflection, (4) the Model M-2 in master/slave mode with force reflection, (5) the BILARM with switchbox controls, and (6) the PaR 6000 with switchbox controls. The experiments examined differences between master/slave systems with and without force reflection and differences between master/slave systems and switchbox-controlled systems. A fourth experiment examined the relative contributions of the remote viewing system and the manipulator system to the performance of remote handling tasks. Results of the experiments showed that operators using the Model M-2 in master/slave mode had significantly faster times to completion than operators using the BILARM in master/slave mode, with about the same error rate per trial. Operators were slower using the BILARM with force reflection than without it, and they committed more errors. There was no statistically significant difference between force-reflection and nonforce-reflection conditions for the M-2 manipulator for any of the performance criteria. Tasks and procedures used in this testing were not sensitive to differences within any single system. No inferences about the effect of force reflection on remote task performance should be made from these data. The two manipulator systems in switchbox mode had significantly slower times to completion than any system in master/slave mode, with approximately the same error rate per trial. There were no significant differences between the BILARM in switchbox mode and the PaR arm

  12. Adaptive control of robotic manipulators

    Science.gov (United States)

    Seraji, H.

    1987-01-01

    The author presents a novel approach to adaptive control of manipulators to achieve trajectory tracking by the joint angles. The central concept in this approach is the utilization of the manipulator inverse as a feedforward controller. The desired trajectory is applied as an input to the feedforward controller which behaves as the inverse of the manipulator at any operating point; the controller output is used as the driving torque for the manipulator. The controller gains are then updated by an adaptation algorithm derived from MRAC (model reference adaptive control) theory to cope with variations in the manipulator inverse due to changes of the operating point. An adaptive feedback controller and an auxiliary signal are also used to enhance closed-loop stability and to achieve faster adaptation. The proposed control scheme is computationally fast and does not require a priori knowledge of the complex dynamic model or the parameter values of the manipulator or the payload.

  13. Effects of harvesting forest biomass on water and climate regulation services: A synthesis of long-term ecosystem experiments in eastern North America

    Science.gov (United States)

    Caputo, Jesse; Beier, Colin D; Groffman, Peter M; Burns, Douglas A.; Beall, Frederick D; Hazlett, Paul W.; Yorks, Thad E

    2016-01-01

    Demand for woody biomass fuels is increasing amidst concerns about global energy security and climate change, but there may be negative implications of increased harvesting for forest ecosystem functions and their benefits to society (ecosystem services). Using new methods for assessing ecosystem services based on long-term experimental research, post-harvest changes in ten potential benefits were assessed for ten first-order northern hardwood forest watersheds at three long-term experimental research sites in northeastern North America. As expected, we observed near-term tradeoffs between biomass provision and greenhouse gas regulation, as well as tradeoffs between intensive harvest and the capacity of the forest to remediate nutrient pollution. In both cases, service provision began to recover along with the regeneration of forest vegetation; in the case of pollution remediation, the service recovered to pre-harvest levels within 10 years. By contrast to these two services, biomass harvesting had relatively nominal and transient impacts on other ecosystem services. Our results are sensitive to empirical definitions of societal demand, including methods for scaling societal demand to ecosystem units, which are often poorly resolved. Reducing uncertainty around these parameters can improve confidence in our results and increase their relevance for decision-making. Our synthesis of long-term experimental studies provides insights on the social-ecological resilience of managed forest ecosystems to multiple drivers of change.

  14. Microbial Community Activity And Plant Biomass Are Insensitive To Passive Warming In A Semiarid Ecosystem

    Science.gov (United States)

    Espinosa, N. J.; Fehmi, J. S.; Rasmussen, C.; Gallery, R. E.

    2017-12-01

    Soil microorganisms drive biogeochemical and nutrient cycling through the production of extracellular enzymes that facilitate organic matter decomposition and the flux of large amounts of carbon dioxide to the atmosphere. Although dryland ecosystems occupy over 40% of land cover and are projected to expand due to climate change, much of our current understanding of these processes comes from mesic temperate ecosystems. Understanding the responses of these globally predominant dryland ecosystems is therefore important yet complicated by co-occurring environmental changes. For example, the widespread and pervasive transition from grass to woody dominated landscapes is changing the hydrology, fire regimes, and carbon storage potential of semiarid ecosystems. In this study, we used a novel passive method of warming to conduct a warming experiment with added plant debris as either woodchip or biochar, to simulate different long-term carbon additions that accompany woody plant encroachment in semiarid ecosystems. The response of heterotrophic respiration, plant biomass, and microbial activity was monitored bi-annually. We hypothesized that the temperature manipulations would have direct and indirect effects on microbial activity. Warmer soils directly reduce the activity of soil extracellular enzymes through denaturation and dehydration of soil pores and indirectly through reducing microbe-available substrates and plant inputs. Overall, reduction in extracellular enzyme activity may reduce decomposition of coarse woody debris and potentially enhance soil carbon storage in semiarid ecosystems. For all seven hydrolytic enzymes examined as well as heterotrophic respiration, there was no consistent or significant response to experimental warming, regardless of seasonal climatic and soil moisture variation. The enzyme results observed here are consistent with the few other experimental results for warming in semiarid ecosystems and indicate that the controls over soil

  15. Impact of climate change on carbon cycle in freshwater ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Kankaala, P.; Ojala, A.; Tulonen, T.; Haapamaeki, J.; Arvola, L. [Helsinki Univ., Lammi (Finland). Lammi Biological Station

    1996-12-31

    The impacts of the expected climate change on Finnish lake ecosystems were studied with the biota of the mesohumic Lake Paeaejaervi, southern Finland. Experimental conditions, from small-scale experiments on single species level to a large-scale ecosystem manipulation, were established to simulate directly the future climate and/or loading of nutrients and dissolved organic matter (DOM) from the drainage area. The experimental studies were accomplished by modelling the carbon flow in the pelagic food web as well as the growth of littoral macrophytes. The main hypothese tested were as follows: As a consequence of the climate change (rising temperature and increasing precipitation) the loading of nutrients and dissolved organic matter (DOM) from the drainage area to the lake will increase. In the pelagic zone this will be first reflected i higher productivity of primary producers and bacteria, but will later affect the entire food chain. Increase in atmospheric CO{sub 2} concentration and ambient temperature as well as longer growing season will enhance the overall productivity of littoral macrophytes. The higher productivity of the littoral zone will be reflected in the pelagic zone an thus may change the whole ecosystem of the lake

  16. Impact of climate change on carbon cycle in freshwater ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Kankaala, P; Ojala, A; Tulonen, T; Haapamaeki, J; Arvola, L [Helsinki Univ., Lammi (Finland). Lammi Biological Station

    1997-12-31

    The impacts of the expected climate change on Finnish lake ecosystems were studied with the biota of the mesohumic Lake Paeaejaervi, southern Finland. Experimental conditions, from small-scale experiments on single species level to a large-scale ecosystem manipulation, were established to simulate directly the future climate and/or loading of nutrients and dissolved organic matter (DOM) from the drainage area. The experimental studies were accomplished by modelling the carbon flow in the pelagic food web as well as the growth of littoral macrophytes. The main hypothese tested were as follows: As a consequence of the climate change (rising temperature and increasing precipitation) the loading of nutrients and dissolved organic matter (DOM) from the drainage area to the lake will increase. In the pelagic zone this will be first reflected i higher productivity of primary producers and bacteria, but will later affect the entire food chain. Increase in atmospheric CO{sub 2} concentration and ambient temperature as well as longer growing season will enhance the overall productivity of littoral macrophytes. The higher productivity of the littoral zone will be reflected in the pelagic zone an thus may change the whole ecosystem of the lake

  17. Image manipulation as research misconduct.

    Science.gov (United States)

    Parrish, Debra; Noonan, Bridget

    2009-06-01

    A growing number of research misconduct cases handled by the Office of Research Integrity involve image manipulations. Manipulations may include simple image enhancements, misrepresenting an image as something different from what it is, and altering specific features of an image. Through a study of specific cases, the misconduct findings associated with image manipulation, detection methods and those likely to identify such manipulations, are discussed. This article explores sanctions imposed against guilty researchers and the factors that resulted in no misconduct finding although relevant images clearly were flawed. Although new detection tools are available for universities and journals to detect questionable images, this article explores why these tools have not been embraced.

  18. The Manipulative Discourse of Gandalf

    Directory of Open Access Journals (Sweden)

    Farid Mohammadi

    2014-07-01

    Full Text Available The aim of this essay is to investigate discursive, cognitive and social aspects of manipulation in regard to the dialogues of the literary fictional character of Gandalf in the trilogy of The Lord of the Rings. Accordingly, the researcher has taken a multidisciplinary approach to an account of discursive manipulation, and focuses on the cognitive dimensions of manipulation. As a result, the researcher demonstrates meticulously how manipulation involves intensifying the power, moral superiority and the credibility of the speaker(s, while abusing the others (recipients, along with an emotional and attractive way of expression, and supplemented by reasonable facts and documents in regard to a specific issue.

  19. Advances in FACE and manipulation techniques

    DEFF Research Database (Denmark)

    Beier, Claus; Larsen, Klaus S.; Mikkelsen, Teis Nørgaard

    Experimental techniques to expose plants and ecosystems to elevated CO2 have been around for decades, starting out with branch cuvettes, chambers and green houses and in the 90ies leading to the development of the FACE (Free Air Carbon Enrichment) technique, which has been and still is widely used....... The FACE technique is used under field conditions and has been developed over the years to be applied for many types of ecosystems from low stature shrub, grass and arable lands to high stature forest trees. These experiments have provided extensive knowledge and data on CO2 effects on individual plants...

  20. nitrogen saturation in stream ecosystems

    OpenAIRE

    Earl, S. R.; Valett, H. M.; Webster, J. R.

    2006-01-01

    The concept of nitrogen (N) saturation has organized the assessment of N loading in terrestrial ecosystems. Here we extend the concept to lotic ecosystems by coupling Michaelis-Menten kinetics and nutrient spiraling. We propose a series of saturation response types, which may be used to characterize the proximity of streams to N saturation. We conducted a series of short-term N releases using a tracer ((NO3)-N-15-N) to measure uptake. Experiments were conducted in streams spanning a gradient ...

  1. Remote inspection manipulators for AGR II: Babcock Power's interstitial manipulator

    International Nuclear Information System (INIS)

    Whyley, S.R.

    1985-01-01

    The interstitial manipulator has been designed and built by Babcock Power for the remote visual inspection of AGR II reactors at Heysham and Torness. Its five drives are operated from a console local to the manipulator on the pile cap, or from a similar console located remotely. The need to operate from an interstitial ISI standpipe has restricted the size of the components entering the reactor, and this has consequently provided the major design constraint. A detailed structural assessment of the manipulator was carried out to demonstrate the ability to operate with payloads in excess of the largest camera weight of 13.6 kg. The manipulator finite element model was also used to determine static deflections, and, as a consequence, has provided data from which the control system is able to predict accurately the camera's position. Other computer aided design techniques have enabled the step by step sequences of manipulator deployment, in the restricted space available, to be successfully demonstrated. (author)

  2. ADVERTISING AND LANGUAGE MANIPULATION

    Directory of Open Access Journals (Sweden)

    Cristina-Maria PRELIPCEANU

    2013-11-01

    Full Text Available Research has revealed that much of what happens in our minds as a result of language use is still hidden from our conscious awareness. Advertisers know this phenomenon better. They use the manipulation of language to suggest something about their products without directly claiming it to be true. Although the advertisers use colours, symbols, and imagery in advertisements, “the most direct way to study ads is through an analysis of the language employed” as all the other aspects are meant to reinforce the language message. Ads are designed to have an effect on consumers while being laughed at, belittle and all but ignored. Some modern advertisements appear to be almost dissuading consumers from the product – but this is just a modern technique. This paper is going to analyze a series of language techniques used by advertisers to arrest our attention, to arouse our interest, to stimulate desire for a product and ultimately to motivate us to buy it. Once we become familiar with the language strategies used in advertising messages we will be more able to make our own buying decisions.

  3. Stud manipulating device

    International Nuclear Information System (INIS)

    Bunyan, T.W.

    1980-01-01

    A device for inserting and removing studs from bores in a workpiece, for example a nuclear reactor vessel, comprises manipulating devices for operating on individual studs, each capable of tensioning a stud slackening a working nut on the stud, and subsequently removing the stud from the bore. A ring has dogs which can engage working nut recesses to interlock with the nut against relative rotation. Motors coupled to the ring rotate the working nut. A top nut is coupled to the motors to rotate the nut and screw it onto the stud. The top nut with other device parts can be raised and lowered on a tube by a hydraulic actuator. A hydraulic load cell between the top nut and a stool on the workpiece is pressurised to tension the stud by means of the top nut and thus facilitate rotation of the working nut when tightening or slackening. A dog clutch mechanism engages a stud end fitting against relative axial and rotational movement. The mechanism is raised and lowered on a guide member by an actuator. The mechanism has a tubular member and the drive coupling for the motors to the top nut includes a tubular member. Tubular members carry teeth which are engaged when the top nut is raised and the clutch mechanism is lowered, to provide a coupling between the motors and the mechanism for rotating the stud. (U.K.)

  4. Magnus force effect in optical manipulation

    International Nuclear Information System (INIS)

    Cipparrone, Gabriella; Pagliusi, Pasquale; Hernandez, Raul Josue; Provenzano, Clementina

    2011-01-01

    The effect of the Magnus force in optical micromanipulation has been observed. An ad hoc experiment has been designed based on a one-dimensional optical trap that carries angular momentum. The observed particle dynamics reveals the occurrence of this hydrodynamic force, which is neglected in the common approach. Its measured value is larger than the one predicted by the existing theoretical models for micrometric particles and low Reynolds number, showing that the Magnus force can contribute to unconventional optohydrodynamic trapping and manipulation.

  5. Manipulation Robustness of Collaborative Filtering

    OpenAIRE

    Benjamin Van Roy; Xiang Yan

    2010-01-01

    A collaborative filtering system recommends to users products that similar users like. Collaborative filtering systems influence purchase decisions and hence have become targets of manipulation by unscrupulous vendors. We demonstrate that nearest neighbors algorithms, which are widely used in commercial systems, are highly susceptible to manipulation and introduce new collaborative filtering algorithms that are relatively robust.

  6. CLIMAN - a mobile manipulator concept

    International Nuclear Information System (INIS)

    Noltingk, B.E.; Owen, C.K.V.

    With increasing age the integrity of more remote parts of reactors, such as the core restraints, is questioned so there is a need for a means of access to these places to carry out inspection, minor repairs and alterations. Conventional standpipe manipulators are about 20 m long so that extending them further presents difficulties of load capacity, rigidity, dexterity and control which must increase steeply with range. The proposal outlined here is for a mobile manipulator which can climb at the end of a cable (CLImbing MANipulator - CLIMAN) into a reactor and reach well beyond the range of a fixed base machine. In addition to virtually unlimited range such a mobile manipulator has twice as many degrees of freedom as a fixed base machine. Its body or base can be manoeuvred with six degrees of freedom so as to obtain the maximum coverage and obstacle avoidance for its manipulator. It is proposed that it should be manually controlled. (author)

  7. Dexterous Manipulation: Making Remote Manipulators Easy to Use

    International Nuclear Information System (INIS)

    HARRIGAN, RAYMOND W.; BENNETT, PHIL C.

    2001-01-01

    Perhaps the most basic barrier to the widespread deployment of remote manipulators is that they are very difficult to use. Remote manual operations are fatiguing and tedious, while fully autonomous systems are seldom able to function in changing and unstructured environments. An alternative approach to these extremes is to exploit computer control while leaving the operator in the loop to take advantage of the operator's perceptual and decision-making capabilities. This report describes research that is enabling gradual introduction of computer control and decision making into operator-supervised robotic manipulation systems, and its integration on a commercially available, manually controlled mobile manipulator

  8. Model ecosystem approach to estimate community level effects of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Masahiro, Doi; Nobuyuki, Tanaka; Shoichi, Fuma; Nobuyoshi, Ishii; Hiroshi, Takeda; Zenichiro, Kawabata [National Institute of Radiological Sciences, Environmental and Toxicological Sciences Research Group, Chiba (Japan)

    2004-07-01

    Mathematical computer model is developed to simulate the population dynamics and dynamic mass budgets of the microbial community realized as a self sustainable aquatic ecological system in the tube. Autotrophic algae, heterotrophic protozoa and sapro-trophic bacteria live symbiotically with inter-species' interactions as predator-prey relationship, competition for the common resource, autolysis of detritus and detritus-grazing food chain, etc. The simulation model is the individual-based parallel model, built in the demographic stochasticity, environmental stochasticity by dividing the aquatic environment into patches. Validity of the model is checked by the multifaceted data of the microcosm experiments. In the analysis, intrinsic parameters of umbrella endpoints (lethality, morbidity, reproductive growth, mutation) are manipulated at the individual level, and tried to find the population level, community level and ecosystem level disorders of ecologically crucial parameters (e.g. intrinsic growth rate, carrying capacity, variation, etc.) that related to the probability of population extinction. (author)

  9. Model ecosystem approach to estimate community level effects of radiation

    International Nuclear Information System (INIS)

    Masahiro, Doi; Nobuyuki, Tanaka; Shoichi, Fuma; Nobuyoshi, Ishii; Hiroshi, Takeda; Zenichiro, Kawabata

    2004-01-01

    Mathematical computer model is developed to simulate the population dynamics and dynamic mass budgets of the microbial community realized as a self sustainable aquatic ecological system in the tube. Autotrophic algae, heterotrophic protozoa and sapro-trophic bacteria live symbiotically with inter-species' interactions as predator-prey relationship, competition for the common resource, autolysis of detritus and detritus-grazing food chain, etc. The simulation model is the individual-based parallel model, built in the demographic stochasticity, environmental stochasticity by dividing the aquatic environment into patches. Validity of the model is checked by the multifaceted data of the microcosm experiments. In the analysis, intrinsic parameters of umbrella endpoints (lethality, morbidity, reproductive growth, mutation) are manipulated at the individual level, and tried to find the population level, community level and ecosystem level disorders of ecologically crucial parameters (e.g. intrinsic growth rate, carrying capacity, variation, etc.) that related to the probability of population extinction. (author)

  10. Linkages of plant stoichiometry to ecosystem production and carbon fluxes with increasing nitrogen inputs in an alpine steppe.

    Science.gov (United States)

    Peng, Yunfeng; Li, Fei; Zhou, Guoying; Fang, Kai; Zhang, Dianye; Li, Changbin; Yang, Guibiao; Wang, Guanqin; Wang, Jun; Yang, Yuanhe

    2017-12-01

    Unprecedented levels of nitrogen (N) have entered terrestrial ecosystems over the past century, which substantially influences the carbon (C) exchange between the atmosphere and biosphere. Temperature and moisture are generally regarded as the major controllers over the N effects on ecosystem C uptake and release. N-phosphorous (P) stoichiometry regulates the growth and metabolisms of plants and soil organisms, thereby affecting many ecosystem C processes. However, it remains unclear how the N-induced shift in the plant N:P ratio affects ecosystem production and C fluxes and its relative importance. We conducted a field manipulative experiment with eight N addition levels in a Tibetan alpine steppe and assessed the influences of N on aboveground net primary production (ANPP), gross ecosystem productivity (GEP), ecosystem respiration (ER), and net ecosystem exchange (NEE); we used linear mixed-effects models to further determine the relative contributions of various factors to the N-induced changes in these parameters. Our results showed that the ANPP, GEP, ER, and NEE all exhibited nonlinear responses to increasing N additions. Further analysis demonstrated that the plant N:P ratio played a dominate role in shaping these C exchange processes. There was a positive relationship between the N-induced changes in ANPP (ΔANPP) and the plant N:P ratio (ΔN:P), whereas the ΔGEP, ΔER, and ΔNEE exhibited quadratic correlations with the ΔN:P. In contrast, soil temperature and moisture were only secondary predictors for the changes in ecosystem production and C fluxes along the N addition gradient. These findings highlight the importance of plant N:P ratio in regulating ecosystem C exchange, which is crucial for improving our understanding of C cycles under the scenarios of global N enrichment. © 2017 John Wiley & Sons Ltd.

  11. The evolution of teleoperated manipulators at ORNL

    International Nuclear Information System (INIS)

    Kress, R.L.; Jansen, J.F.; Noakes, M.W.; Herndon, J.N.

    1996-01-01

    ORNL has made significant contributions to teleoperator and telerobotics technology for two decades and continues with an aggressive program today. Examples of past projects are: (1) the M2 servomanipulator, which was the first digitally controlled teleoperator; (2) the Advanced Servomanipulator (ASM), which was the first remotely maintainable teleoperator; (3) the CESARm/Kraft dissimilar teleoperated system; and (4) the Laboratory Telerobotic Manipulator (LTM), a 7-Degree-of-Freedom (7-DOF) telerobot built as a prototype for work in space. More recently, ORNL has become heavily involved with Environmental Restoration and Waste Management (ERWM) robotics programs funded by the Department of Energy (DOE). The ERWM program requires high payloads and high dexterity. As a result, a hydraulically actuated, dual-arm system comprised of two 6-DOF arms mounted on a 5-DOF base has been constructed and is being used today for various research tasks and for decontamination and dismantlement activities. All of these teleoperated manipulator systems build upon the experiences gained throughout the almost two decades of development. Each system incorporates not only the latest technology in computers, sensors, and electronics, but each new . system also adds at least one new feature to the technologies already developed and demonstrated in the previous system(s). As a result of this process, a serious study of these manipulator systems is a study in the evolution of teleoperated manipulator the systems in general. This provides insight not only into the research and development paths chosen in the past, but also into the appropriate directions for future teleoperator and telerobotics research. This paper examines each of the teleoperated/telerobotic systems developed at ORNL, summarizes their features and capabilities, examines the state of the most current telerobotic system (the Dual Arm Work Module), PM provides direction for a Next Generation Telerobotic Manipulator system

  12. Direct Manipulation in Virtual Reality

    Science.gov (United States)

    Bryson, Steve

    2003-01-01

    Virtual Reality interfaces offer several advantages for scientific visualization such as the ability to perceive three-dimensional data structures in a natural way. The focus of this chapter is direct manipulation, the ability for a user in virtual reality to control objects in the virtual environment in a direct and natural way, much as objects are manipulated in the real world. Direct manipulation provides many advantages for the exploration of complex, multi-dimensional data sets, by allowing the investigator the ability to intuitively explore the data environment. Because direct manipulation is essentially a control interface, it is better suited for the exploration and analysis of a data set than for the publishing or communication of features found in that data set. Thus direct manipulation is most relevant to the analysis of complex data that fills a volume of three-dimensional space, such as a fluid flow data set. Direct manipulation allows the intuitive exploration of that data, which facilitates the discovery of data features that would be difficult to find using more conventional visualization methods. Using a direct manipulation interface in virtual reality, an investigator can, for example, move a data probe about in space, watching the results and getting a sense of how the data varies within its spatial volume.

  13. Manipulating early pig embryos.

    Science.gov (United States)

    Niemann, H; Reichelt, B

    1993-01-01

    On the basis of established surgical procedures for embryo recovery and transfer, the early pig embryo can be subjected to various manipulations aimed at a long-term preservation of genetic material, the generation of identical multiplets, the early determination of sex or the alteration of the genetic make-up. Most of these procedures are still at an experimental stage and despite recent considerable progress are far from practical application. Normal piglets have been obtained after cryopreservation of pig blastocysts hatched in vitro, whereas all attempts to freeze embryos with intact zona pellucida have been unsuccessful. Pig embryos at the morula and blastocyst stage can be bisected microsurgically and the resulting demi-embryos possess a high developmental potential in vitro, whereas their development in vivo is impaired. Pregnancy rates are similar (80%) but litter size is reduced compared with intact embryos and twinning rate is approximately 2%. Pig blastomeres isolated from embryos up to the 16-cell stage can be grown in culture and result in normal blastocysts. Normal piglets have been born upon transfer of blastocysts derived from isolated eight-cell blastomeres, clearly underlining the totipotency of this developmental stage. Upon nuclear transfer the developmental capacity of reconstituted pig embryos is low and culture. Sex determination can be achieved either by separation of X and Y chromosome bearing spermatozoa by flow cytometry or by analysing the expression of the HY antigen in pig embryos from the eight-cell to morula stage. Microinjection of foreign DNA has been successfully used to alter growth and development of transgenic pigs, and to produce foreign proteins in the mammary gland or in the bloodstream, indicating that pigs can be used as donors for valuable human pharmaceutical proteins. Another promising area of gene transfer is the increase of disease resistance in transgenic lines of pigs. Approximately 30% of pig spermatozoa bind

  14. Kinematic sensitivity of robot manipulators

    Science.gov (United States)

    Vuskovic, Marko I.

    1989-01-01

    Kinematic sensitivity vectors and matrices for open-loop, n degrees-of-freedom manipulators are derived. First-order sensitivity vectors are defined as partial derivatives of the manipulator's position and orientation with respect to its geometrical parameters. The four-parameter kinematic model is considered, as well as the five-parameter model in case of nominally parallel joint axes. Sensitivity vectors are expressed in terms of coordinate axes of manipulator frames. Second-order sensitivity vectors, the partial derivatives of first-order sensitivity vectors, are also considered. It is shown that second-order sensitivity vectors can be expressed as vector products of the first-order sensitivity vectors.

  15. Modeling manipulation in medical education.

    Science.gov (United States)

    Dailey, Jason I

    2010-05-01

    As residents and medical students progress through their medical training, they are presented with multiple instances in which they feel they must manipulate the healthcare system and deceive others in order to efficiently treat their patients. This, however, creates a culture of manipulation resulting in untoward effects on trainees' ethical and professional development. Yet manipulation need not be a skill necessary to practice medicine, and steps should be taken by both individuals and institutions to combat the view that the way medicine must be practiced "in the real world" is somehow different from what one's affective moral sense implores.

  16. Spatial pattern enhances ecosystem functioning in an African savanna.

    Directory of Open Access Journals (Sweden)

    Robert M Pringle

    2010-05-01

    Full Text Available The finding that regular spatial patterns can emerge in nature from local interactions between organisms has prompted a search for the ecological importance of these patterns. Theoretical models have predicted that patterning may have positive emergent effects on fundamental ecosystem functions, such as productivity. We provide empirical support for this prediction. In dryland ecosystems, termite mounds are often hotspots of plant growth (primary productivity. Using detailed observations and manipulative experiments in an African savanna, we show that these mounds are also local hotspots of animal abundance (secondary and tertiary productivity: insect abundance and biomass decreased with distance from the nearest termite mound, as did the abundance, biomass, and reproductive output of insect-eating predators. Null-model analyses indicated that at the landscape scale, the evenly spaced distribution of termite mounds produced dramatically greater abundance, biomass, and reproductive output of consumers across trophic levels than would be obtained in landscapes with randomly distributed mounds. These emergent properties of spatial pattern arose because the average distance from an arbitrarily chosen point to the nearest feature in a landscape is minimized in landscapes where the features are hyper-dispersed (i.e., uniformly spaced. This suggests that the linkage between patterning and ecosystem functioning will be common to systems spanning the range of human management intensities. The centrality of spatial pattern to system-wide biomass accumulation underscores the need to conserve pattern-generating organisms and mechanisms, and to incorporate landscape patterning in efforts to restore degraded habitats and maximize the delivery of ecosystem services.

  17. The role of recurrent disturbances for ecosystem multifunctionality

    OpenAIRE

    Villnäs, Anna; Norkko, Joanna; Hietanen, Susanna; Josefson, Alf; Lukkari, Kaarina; Norkko, Alf

    2013-01-01

    Ecosystem functioning is threatened by an increasing number of anthropogenic stressors, creating a legacy of disturbance that undermines ecosystem resilience. However, few empirical studies have assessed to what extent an ecosystem can tolerate repeated disturbances and sustain its multiple functions. By inducing increasingly recurring hypoxic disturbances to a sedimentary ecosystem, we show that the majority of individual ecosystem functions experience gradual degradation patterns in respons...

  18. Single-photon manipulation in Nanophotonic Circuits

    DEFF Research Database (Denmark)

    Hansen, Sofie Lindskov

    Quantum dots in photonic nanostructures has long been known to be a very powerful and versatile solid-state platform for conducting quantum optics experiments. The present PhD thesis describes experimental demonstrations of single-photon generation and subsequent manipulation all realized...... on a gallium arsenide platform. This platform offers near-unity coupling between embedded single-photon emitters and a photonic mode, as well as the ability to suppress decoherence mechanisms, making it highly suited for quantum information applications. In this thesis we show how a single-photon router can...... be realized on a chip with embedded quantum dots. This allows for on-chip generation and manipulation of single photons. The router consists of an on-chip interferometer where the phase difference between the arms of the interferometer is controlled electrically. The response time of the device...

  19. Final Technical Report: Effects of Changing Water and Nitrogen Inputs on a Mojave Desert Ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Stanley, D.; Nowak, Robert S.; Fenstermaker, Lynn, F.; Young, Michael,H.

    2007-11-30

    In order to anticipate the effects of global change on ecosystem function, it is essential that predictive relationships be established linking ecosystem function to global change scenarios. The Mojave Desert is of considerable interest with respect to global change. It contains the driest habitats in North America, and thus most closely approximates the world’s great arid deserts. In order to examine the effects of climate and land use changes, in 2001 we established a long-term manipulative global change experiment, called the Mojave Global Change Facility. Manipulations in this study include the potential effects of (1) increased summer rainfall (75 mm over three discrete 25 mm events), (2) increased nitrogen deposition (10 and 40 kg ha-1), and (3) the disturbance of biological N-fixing crusts . Questions addressed under this grant shared the common hypothesis that plant and ecosystem performance will positively respond to the augmentation of the most limiting resources to plant growth in the Mojave Desert, e.g., water and nitrogen. Specific hypotheses include (1) increased summer rainfall will significantly increase plant production through an alleviation of moisture stress in the dry summer months, (2) N-deposition will increase plant production in this N-limited system, particularly in wet years or in concert with added summer rain, and (3) biological crust disturbance will gradually decrease bio-available N, with concomitant long-term reductions in photosynthesis and ANPP. Individual plant and ecosystem responses to global change may be regulated by biogeochemical processes and natural weather variability, and changes in plant and ecosystem processes may occur rapidly, may occur only after a time lag, or may not occur at all. During the first PER grant period, we observed changes in plant and ecosystem processes that would fall under each of these time-response intervals: plant and ecosystem processes responded rapidly to added summer rain, whereas most

  20. Analysis and design of software ecosystem architectures – Towards the 4S telemedicine ecosystem

    DEFF Research Database (Denmark)

    Christensen, Henrik Bærbak; Hansen, Klaus Marius; Kyng, Morten

    2014-01-01

    performed a descriptive, revelatory case study of the Danish telemedicine ecosystem and for ii), we experimentally designed, implemented, and evaluated the architecture of 4S. Results We contribute in three areas. First, we define the software ecosystem architecture concept that captures organization......, and application stove-pipes that inhibit the adoption of telemedical solutions. To which extent can a software ecosystem approach to telemedicine alleviate this? Objective In this article, we define the concept of software ecosystem architecture as the structure(s) of a software ecosystem comprising elements...... experience in creating and evolving the 4S telemedicine ecosystem. Conclusion The concept of software ecosystem architecture can be used analytically and constructively in respectively the analysis and design of software ecosystems....

  1. Dielectrophoretic Manipulation and Separation of Microparticles Using Microarray Dot Electrodes

    Directory of Open Access Journals (Sweden)

    Bashar Yafouz

    2014-04-01

    Full Text Available This paper introduces a dielectrophoretic system for the manipulation and separation of microparticles. The system is composed of five layers and utilizes microarray dot electrodes. We validated our system by conducting size-dependent manipulation and separation experiments on 1, 5 and 15 μm polystyrene particles. Our findings confirm the capability of the proposed device to rapidly and efficiently manipulate and separate microparticles of various dimensions, utilizing positive and negative dielectrophoresis (DEP effects. Larger size particles were repelled and concentrated in the center of the dot by negative DEP, while the smaller sizes were attracted and collected by the edge of the dot by positive DEP.

  2. Computational simulator of robotic manipulators

    International Nuclear Information System (INIS)

    Leal, Alexandre S.; Campos, Tarcisio P.R.

    1995-01-01

    Robotic application for industrial plants is discussed and a computational model for a mechanical manipulator of three links is presented. A neural network feed-forward type has been used to model the dynamic control of the manipulator. A graphic interface was developed in C programming language as a virtual world in order to visualize and simulate the arm movements handling radioactive waste environment. (author). 7 refs, 5 figs

  3. Can earnings manipulation create value?

    OpenAIRE

    Anton Miglo

    2008-01-01

    Existing literature usually considers earnings manipulation to be a negative social phenomenon. We argue that earnings manipulation can be a part of the equilibrium relationships between firm's insiders and outsiders. We consider an optimal contract between an entrepreneur and an investor where the entrepreneur is subject to a double moral hazard problem (one being the choice of production effort and the other being intertemporal substitution, which consists of transferring cash flows between...

  4. Precision spectral manipulation: A demonstration using a coherent optical memory

    Energy Technology Data Exchange (ETDEWEB)

    Sparkes, B. M.; Cairns, C.; Hosseini, M.; Higginbottom, D.; Campbell, G. T.; Lam, P. K.; Buchler, B. C. [Centre for Quantum Computation and Communication Technology, The Australian National University, Canberra (Australia)

    2014-12-04

    The ability to coherently spectrally manipulate quantum information has the potential to improve qubit rates across quantum channels and find applications in optical quantum computing. Here we present experiments that use a multi-element solenoid combined with the three-level gradient echo memory scheme to perform precision spectral manipulation of optical pulses. If applied in a quantum information network, these operations would enable frequency-based multiplexing of qubits.

  5. Integration of Mobile Manipulators in an Industrial Production

    DEFF Research Database (Denmark)

    Madsen, Ole; Bøgh, Simon; Schou, Casper

    2015-01-01

    Purpose – The purpose of this study has been to evaluate the technology of autonomous mobile manipulation in a real world industrial manufacturing environment. The objective has been to obtain experience in the integration with existing equipment and determine key challenges in maturing...... reports from such a real-world industrial experiment with two mobile manipulators. Design/methodology/approach – In the experiment, autonomous industrial mobile manipulators are integrated into the actual manufacturing environment of the pump manufacturer Grundfos. The two robots together solve the task...... of producing rotors; a task constituted by several sub-tasks ranging from logistics to complex assembly. With a total duration of 10 days, the experiment includes workspace adaptation, safety regulations, rapid robot instruction and running production. Findings – With a setup time of less than one day...

  6. Measuring Entrepreneurial Ecosystems

    OpenAIRE

    Stam, F.C.

    2017-01-01

    How can entrepreneurial ecosystems and productive entrepreneurship can be traced empirically and how is entrepreneurship related to entrepreneurial ecosystems. The analyses in this chapter show the value of taking a systems view on the context of entrepreneurship. We measure entrepreneurial ecosystem elements and use these to compose an entrepreneurial ecosystem index. Next, we measure the output of entrepreneurial ecosystems with different indicators of high-growth firms. We use the 12 provi...

  7. Mapping Ecosystem Services

    OpenAIRE

    Georgiev,Teodor; Burkhard,Benjamin; Maes,Joachim

    2017-01-01

    Ecosystem services are the contributions of ecosystem structure and function (in combination with other inputs) to human well-being. That means, humankind is strongly dependent on well-functioning ecosystems and natural capital that are the base for a constant flow of ecosystem services from nature to society. Therefore ecosystem services have the potential to become a major tool for policy and decision making on global, national, regional and local scales. Possible applications are manifold:...

  8. Payment for Ecosystem Services | Benjamin | Potchefstroom ...

    African Journals Online (AJOL)

    This address focuses on the legislative design for payment or ecosystem services (PES) since most countries do not have specific legislation that addresses the subject. Brazil is in the process of drafting national legislation on ecosystem services and there are several important issues that can be learnt from this experience.

  9. Parallel Computing for Terrestrial Ecosystem Carbon Modeling

    International Nuclear Information System (INIS)

    Wang, Dali; Post, Wilfred M.; Ricciuto, Daniel M.; Berry, Michael

    2011-01-01

    Terrestrial ecosystems are a primary component of research on global environmental change. Observational and modeling research on terrestrial ecosystems at the global scale, however, has lagged behind their counterparts for oceanic and atmospheric systems, largely because the unique challenges associated with the tremendous diversity and complexity of terrestrial ecosystems. There are 8 major types of terrestrial ecosystem: tropical rain forest, savannas, deserts, temperate grassland, deciduous forest, coniferous forest, tundra, and chaparral. The carbon cycle is an important mechanism in the coupling of terrestrial ecosystems with climate through biological fluxes of CO 2 . The influence of terrestrial ecosystems on atmospheric CO 2 can be modeled via several means at different timescales. Important processes include plant dynamics, change in land use, as well as ecosystem biogeography. Over the past several decades, many terrestrial ecosystem models (see the 'Model developments' section) have been developed to understand the interactions between terrestrial carbon storage and CO 2 concentration in the atmosphere, as well as the consequences of these interactions. Early TECMs generally adapted simple box-flow exchange models, in which photosynthetic CO 2 uptake and respiratory CO 2 release are simulated in an empirical manner with a small number of vegetation and soil carbon pools. Demands on kinds and amount of information required from global TECMs have grown. Recently, along with the rapid development of parallel computing, spatially explicit TECMs with detailed process based representations of carbon dynamics become attractive, because those models can readily incorporate a variety of additional ecosystem processes (such as dispersal, establishment, growth, mortality etc.) and environmental factors (such as landscape position, pest populations, disturbances, resource manipulations, etc.), and provide information to frame policy options for climate change

  10. High precision redundant robotic manipulator

    International Nuclear Information System (INIS)

    Young, K.K.D.

    1998-01-01

    A high precision redundant robotic manipulator for overcoming contents imposed by obstacles or imposed by a highly congested work space is disclosed. One embodiment of the manipulator has four degrees of freedom and another embodiment has seven degrees of freedom. Each of the embodiments utilize a first selective compliant assembly robot arm (SCARA) configuration to provide high stiffness in the vertical plane, a second SCARA configuration to provide high stiffness in the horizontal plane. The seven degree of freedom embodiment also utilizes kinematic redundancy to provide the capability of avoiding obstacles that lie between the base of the manipulator and the end effector or link of the manipulator. These additional three degrees of freedom are added at the wrist link of the manipulator to provide pitch, yaw and roll. The seven degrees of freedom embodiment uses one revolute point per degree of freedom. For each of the revolute joints, a harmonic gear coupled to an electric motor is introduced, and together with properly designed based servo controllers provide an end point repeatability of less than 10 microns. 3 figs

  11. Artificial Light at Night Affects Organism Flux across Ecosystem Boundaries and Drives Community Structure in the Recipient Ecosystem

    Directory of Open Access Journals (Sweden)

    Alessandro Manfrin

    2017-10-01

    Full Text Available Artificial light at night (ALAN is a widespread alteration of the natural environment that can affect the functioning of ecosystems. ALAN can change the movement patterns of freshwater animals that move into the adjacent riparian and terrestrial ecosystems, but the implications for local riparian consumers that rely on these subsidies are still unexplored. We conducted a 2-year field experiment to quantify changes of freshwater-terrestrial linkages by installing streetlights in a previously light-naïve riparian area adjacent to an agricultural drainage ditch. We compared the abundance and community composition of emerging aquatic insects, flying insects, and ground-dwelling arthropods with an unlit control site. Comparisons were made within and between years using two-way generalized least squares (GLS model and a BACI design (Before-After Control-Impact. Aquatic insect emergence, the proportion of flying insects that were aquatic in origin, and the total abundance of flying insects all increased in the ALAN-illuminated area. The abundance of several night-active ground-dwelling predators (Pachygnatha clercki, Trochosa sp., Opiliones increased under ALAN and their activity was extended into the day. Conversely, the abundance of nocturnal ground beetles (Carabidae decreased under ALAN. The changes in composition of riparian predator and scavenger communities suggest that the increase in aquatic-to-terrestrial subsidy flux may cascade through the riparian food web. The work is among the first studies to experimentally manipulate ALAN using a large-scale field experiment, and provides evidence that ALAN can affect processes that link adjacent ecosystems. Given the large number of streetlights that are installed along shorelines of freshwater bodies throughout the globe, the effects could be widespread and represent an underestimated source of impairment for both aquatic and riparian systems.

  12. Does brood size manipulation affect later competitive behaviour of offspring?

    NARCIS (Netherlands)

    deKogel, CH

    Data from several field experiments support the existence of a trade-off between number and quality of offspring. However, long term effects of brood size on fitness related traits of offspring have been a relatively neglected area of research. In a laboratory experiment the effect of manipulated

  13. Response of soil CO2 efflux to precipitation manipulation in a semiarid grassland.

    Science.gov (United States)

    Wei, Xiaorong; Zhang, Yanjiang; Liu, Jian; Gao, Hailong; Fan, Jun; Jia, Xiaoxu; Cheng, Jimin; Shao, Mingan; Zhang, Xingchang

    2016-07-01

    Soil CO2 efflux (SCE) is an important component of ecosystem CO2 exchange and is largely temperature and moisture dependent, providing feedback between C cycling and the climate system. We used a precipitation manipulation experiment to examine the effects of precipitation treatment on SCE and its dependences on soil temperature and moisture in a semiarid grassland. Precipitation manipulation included ambient precipitation, decreased precipitation (-43%), or increased precipitation (+17%). The SCE was measured from July 2013 to December 2014, and CO2 emission during the experimental period was assessed. The response curves of SCE to soil temperature and moisture were analyzed to determine whether the dependence of SCE on soil temperature or moisture varied with precipitation manipulation. The SCE significantly varied seasonally but was not affected by precipitation treatments regardless of season. Increasing precipitation resulted in an upward shift of SCE-temperature response curves and rightward shift of SCE-moisture response curves, while decreasing precipitation resulted in opposite shifts of such response curves. These shifts in the SCE response curves suggested that increasing precipitation strengthened the dependence of SCE on temperature or moisture, and decreasing precipitation weakened such dependences. Such shifts affected the predictions in soil CO2 emissions for different precipitation treatments. When considering such shifts, decreasing or increasing precipitation resulted in 43 or 75% less change, respectively, in CO2 emission compared with changes in emissions predicted without considering such shifts. Furthermore, the effects of shifts in SCE response curves on CO2 emission prediction were greater during the growing than the non-growing season. Copyright © 2016. Published by Elsevier B.V.

  14. Autonomous Industrial Mobile Manipulation (AIMM)

    DEFF Research Database (Denmark)

    Hvilshøj, Mads; Bøgh, Simon; Nielsen, Oluf Skov

    2012-01-01

    Purpose - The purpose of this paper is to provide a review of the interdisciplinary research field Autonomous Industrial Mobile Manipulation (AIMM), with an emphasis on physical implementations and applications. Design/methodology/approach - Following an introduction to AIMM, this paper investiga......Purpose - The purpose of this paper is to provide a review of the interdisciplinary research field Autonomous Industrial Mobile Manipulation (AIMM), with an emphasis on physical implementations and applications. Design/methodology/approach - Following an introduction to AIMM, this paper......; sustainability, configuration, adaptation, autonomy, positioning, manipulation and grasping, robot-robot interaction, human-robot interaction, process quality, dependability, and physical properties. Findings - The concise yet comprehensive review provides both researchers (academia) and practitioners (industry......) with a quick and gentle overview of AIMM. Furthermore, the paper identifies key open issues and promising research directions to realize real-world integration and maturation of the AIMM technology. Originality/value - This paper reviews the interdisciplinary research field Autonomous Industrial Mobile...

  15. Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO2 exposure in a subtropical oak woodland

    Science.gov (United States)

    Hungate, Bruce A; Dijkstra, Paul; Wu, Zhuoting; Duval, Benjamin D; Day, Frank P; Johnson, Dale W; Megonigal, J Patrick; Brown, Alisha L P; Garland, Jay L

    2013-01-01

    Summary Rising atmospheric carbon dioxide (CO2) could alter the carbon (C) and nitrogen (N) content of ecosystems, yet the magnitude of these effects are not well known. We examined C and N budgets of a subtropical woodland after 11 yr of exposure to elevated CO2. We used open-top chambers to manipulate CO2 during regrowth after fire, and measured C, N and tracer 15N in ecosystem components throughout the experiment. Elevated CO2 increased plant C and tended to increase plant N but did not significantly increase whole-system C or N. Elevated CO2 increased soil microbial activity and labile soil C, but more slowly cycling soil C pools tended to decline. Recovery of a long-term 15N tracer indicated that CO2 exposure increased N losses and altered N distribution, with no effect on N inputs. Increased plant C accrual was accompanied by higher soil microbial activity and increased C losses from soil, yielding no statistically detectable effect of elevated CO2 on net ecosystem C uptake. These findings challenge the treatment of terrestrial ecosystems responses to elevated CO2 in current biogeochemical models, where the effect of elevated CO2 on ecosystem C balance is described as enhanced photosynthesis and plant growth with decomposition as a first-order response. PMID:23718224

  16. Cumulative response of ecosystem carbon and nitrogen stocks to chronic CO₂ exposure in a subtropical oak woodland.

    Science.gov (United States)

    Hungate, Bruce A; Dijkstra, Paul; Wu, Zhuoting; Duval, Benjamin D; Day, Frank P; Johnson, Dale W; Megonigal, J Patrick; Brown, Alisha L P; Garland, Jay L

    2013-11-01

    Rising atmospheric carbon dioxide (CO₂) could alter the carbon (C) and nitrogen (N) content of ecosystems, yet the magnitude of these effects are not well known. We examined C and N budgets of a subtropical woodland after 11 yr of exposure to elevated CO₂. We used open-top chambers to manipulate CO₂ during regrowth after fire, and measured C, N and tracer (15) N in ecosystem components throughout the experiment. Elevated CO₂ increased plant C and tended to increase plant N but did not significantly increase whole-system C or N. Elevated CO₂ increased soil microbial activity and labile soil C, but more slowly cycling soil C pools tended to decline. Recovery of a long-term (15) N tracer indicated that CO₂ exposure increased N losses and altered N distribution, with no effect on N inputs. Increased plant C accrual was accompanied by higher soil microbial activity and increased C losses from soil, yielding no statistically detectable effect of elevated CO₂ on net ecosystem C uptake. These findings challenge the treatment of terrestrial ecosystems responses to elevated CO₂ in current biogeochemical models, where the effect of elevated CO₂ on ecosystem C balance is described as enhanced photosynthesis and plant growth with decomposition as a first-order response. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  17. Understanding pharmaceutical research manipulation in the context of accounting manipulation.

    Science.gov (United States)

    Brown, Abigail

    2013-01-01

    The problem of the manipulation of data that arises when there is both opportunity and incentive to mislead is better accepted and studied - though by no means solved - in financial accounting than in medicine. This article analyzes pharmaceutical company manipulation of medical research as part of a broader problem of corporate manipulation of data in the creation of accounting profits. The article explores how our understanding of accounting fraud and misinformation helps us understand the risk of similar information manipulation in the medical sciences. This understanding provides a framework for considering how best to improve the quality of medical research and analysis in light of the current system of medical information production. I offer three possible responses: (1) use of the Dodd-Frank whistleblower provisions to encourage reporting of medical research fraud; (2) a two-step academic journal review process for clinical trials; and (3) publicly subsidized trial-failure insurance. These would improve the release of negative information about drugs, thereby increasing the reliability of positive information. © 2013 American Society of Law, Medicine & Ethics, Inc.

  18. Transformation of Digital Ecosystems

    DEFF Research Database (Denmark)

    Henningsson, Stefan; Hedman, Jonas

    2014-01-01

    the Digital Ecosystem Technology Transformation (DETT) framework for explaining technology-based transformation of digital ecosystems by integrating theories of business and technology ecosystems. The framework depicts ecosystem transformation as distributed and emergent from micro-, meso-, and macro- level......In digital ecosystems, the fusion relation between business and technology means that the decision of technical compatibility of the offering is also the decision of how to position the firm relative to the coopetive relations that characterize business ecosystems. In this article we develop...... coopetition. The DETT framework consists an alternative to the existing explanations of digital ecosystem transformation as the rational management of one central actor balancing ecosystem tensions. We illustrate the use of the framework by a case study of transformation in the digital payment ecosystem...

  19. Ecosystem degradation in India

    International Nuclear Information System (INIS)

    Sinha, B.N.

    1990-01-01

    Environmental and ecosystem studies have assumed greater relevance in the last decade of the twentieth century than even before. The urban settlements are becoming over-crowded and industries are increasingly polluting the air, water and sound in our larger metropolises. Degradation of different types of ecosystem are discussed in this book, Ecosystem Degradation in India. The book has been divided into seven chapters: Introduction, Coastal and Delta Ecosystem, River Basin Ecosystem, Mountain Ecosystem, Forest Ecosystem, Urban Ecosystem and the last chapter deals with the Environmental Problems and Planning. In the introduction the environmental and ecosystem degradation problems in India is highlighted as a whole while in other chapters mostly case studies by experts who know their respective terrain very intimately are included. The case study papers cover most part of India and deal with local problems, stretching from east coast to west coast and from Kashmir to Kanyakumari. (author)

  20. Learning Area and Perimeter with Virtual Manipulatives

    Science.gov (United States)

    Bouck, Emily; Flanagan, Sara; Bouck, Mary

    2015-01-01

    Manipulatives are considered a best practice for educating students with disabilities, but little research exists which examines virtual manipulatives as tool for supporting students in mathematics. This project investigated the use of a virtual manipulative through the National Library of Virtual Manipulatives--polynominoes (i.e., tiles)--as a…

  1. A six degrees of freedom mems manipulator

    NARCIS (Netherlands)

    de Jong, B.R.

    2006-01-01

    This thesis reports about a six degrees of freedom (DOF) precision manipulator in MEMS, concerning concept generation for the manipulator followed by design and fabrication (of parts) of the proposed manipulation concept in MEMS. Researching the abilities of 6 DOF precision manipulation in MEMS is

  2. Repetitive motion planning and control of redundant robot manipulators

    CERN Document Server

    Zhang, Yunong

    2013-01-01

    Repetitive Motion Planning and Control of Redundant Robot Manipulators presents four typical motion planning schemes based on optimization techniques, including the fundamental RMP scheme and its extensions. These schemes are unified as quadratic programs (QPs), which are solved by neural networks or numerical algorithms. The RMP schemes are demonstrated effectively by the simulation results based on various robotic models; the experiments applying the fundamental RMP scheme to a physical robot manipulator are also presented. As the schemes and the corresponding solvers presented in the book have solved the non-repetitive motion problems existing in redundant robot manipulators, it is of particular use in applying theoretical research based on the quadratic program for redundant robot manipulators in industrial situations. This book will be a valuable reference work for engineers, researchers, advanced undergraduate and graduate students in robotics fields. Yunong Zhang is a professor at The School of Informa...

  3. A motion sensing-based framework for robotic manipulation.

    Science.gov (United States)

    Deng, Hao; Xia, Zeyang; Weng, Shaokui; Gan, Yangzhou; Fang, Peng; Xiong, Jing

    2016-01-01

    To data, outside of the controlled environments, robots normally perform manipulation tasks operating with human. This pattern requires the robot operators with high technical skills training for varied teach-pendant operating system. Motion sensing technology, which enables human-machine interaction in a novel and natural interface using gestures, has crucially inspired us to adopt this user-friendly and straightforward operation mode on robotic manipulation. Thus, in this paper, we presented a motion sensing-based framework for robotic manipulation, which recognizes gesture commands captured from motion sensing input device and drives the action of robots. For compatibility, a general hardware interface layer was also developed in the framework. Simulation and physical experiments have been conducted for preliminary validation. The results have shown that the proposed framework is an effective approach for general robotic manipulation with motion sensing control.

  4. Intelligent Switching Control of Pneumatic Artificial Muscle Manipulator

    Science.gov (United States)

    Ahn, Kyoung Kwan; Thanh, Tu Diep Cong; Ahn, Young Kong

    Problems with the control, oscillatory motion and compliance of pneumatic systems have prevented their widespread use in advanced robotics. However, their compactness, power/weight ratio, ease of maintenance and inherent safety are the factors that could potentially be exploited in sophisticated dexterous manipulator designs. These advantages have led to the development of novel actuators such as the McKibben Muscle, Rubber Actuator and Pneumatic Artificial Muscle Manipulators. However, some limitations still exist, such as deterioration of the performance of transient response due to the change of the external inertia load in the pneumatic artificial muscle manipulator. To overcome this problem, switching algorithm of control parameter using learning vector quantization neural network (LVQNN) is newly proposed, which estimates the external inertia load of the pneumatic artificial muscle manipulator. The effectiveness of the proposed control algorithm is demonstrated through experiments with different external inertia loads.

  5. Manipulator vehicles and loading shovels

    International Nuclear Information System (INIS)

    Brudermueller, G.; Krueger, W.

    1992-01-01

    Kerntechnische Hilfsdienst GmbH (KHG) is an institution jointly founded by electricity utilities, fuel cycle industries, and national research centers to provide specialist equipment for removing the consequences of accidents inside plants and recognizing damage in the immediate vicinity of such plants, maintain such equipment in an operational condition, and provide personnel instructed in work of this kind. The specialized technical equipment developed includes carriages, carrier vehicles for manipulators, grabs, TV cameras or measuring gear. In addition to manipulator vehicles, especially loading shovels are used. Radio-controlled vehicles are used where cable operation is either not reliable enough or has failed. (orig.) [de

  6. Dietary manipulations for improving productivity in ruminant livestock

    International Nuclear Information System (INIS)

    Beever, D.E.

    1989-01-01

    Against a background of the major aspects of forage utilization by the rumen ecosystem and host animal metabolism, the need to manipulate the nature of the diet in order to improve animal productivity is reviewed. A number of criteria by which possible dietary manipulants should be considered are provided. The role of feed additives to manipulate rumen fermentation characteristics with respect to volatile fatty acid production, suppression of methanogenesis, and stimulation of microbial protein synthesis is discussed, and the possible benefits of changing the rumen microflora (e.g. by defaunation) are considered. The potential of nitrogen, energy and specific amino acid supplements to enhance rumen fermentation and/or nutrient absorption is examined and the paper concludes with consideration of possible areas where dietary manipulation could be beneficial, but to date suitable technology has not been satisfactorily developed. In this context, the nutritional effect of tannins, including enhancement of pronutritional and diminution of antinutritional factors, the suppression of rumen proteolysis and the ruminal protection of starch are examined. (author). 74 refs, 1 tab

  7. Leadership Manipulation and Ethics in Storytelling

    OpenAIRE

    Auvinen, Tommi; Lämsä, Anna-Maija; Sintonen, Teppo; Takala, Tuomo

    2013-01-01

    This article focuses on exerting influence in leadership, namely manipulation in storytelling. Manipulation is usually considered an unethical approach to leadership. We will argue that manipulation is a more complex phenomenon than just an unethical way of acting in leadership. We will demonstrate through an empirical qualitative study that there are various types of manipulation through storytelling. This article makes a contribution to the literature on manipulation through leadership stor...

  8. Dynamic Control of Kinematically Redundant Robotic Manipulators

    Directory of Open Access Journals (Sweden)

    Erling Lunde

    1987-07-01

    Full Text Available Several methods for task space control of kinematically redundant manipulators have been proposed in the literature. Most of these methods are based on a kinematic analysis of the manipulator. In this paper we propose a control algorithm in which we are especially concerned with the manipulator dynamics. The algorithm is particularly well suited for the class of redundant manipulators consisting of a relatively small manipulator mounted on a larger positioning part.

  9. Plant functional types in Earth system models: past experiences and future directions for application of dynamic vegetation models in high-latitude ecosystems.

    Science.gov (United States)

    Wullschleger, Stan D; Epstein, Howard E; Box, Elgene O; Euskirchen, Eugénie S; Goswami, Santonu; Iversen, Colleen M; Kattge, Jens; Norby, Richard J; van Bodegom, Peter M; Xu, Xiaofeng

    2014-07-01

    Earth system models describe the physical, chemical and biological processes that govern our global climate. While it is difficult to single out one component as being more important than another in these sophisticated models, terrestrial vegetation is a critical player in the biogeochemical and biophysical dynamics of the Earth system. There is much debate, however, as to how plant diversity and function should be represented in these models. Plant functional types (PFTs) have been adopted by modellers to represent broad groupings of plant species that share similar characteristics (e.g. growth form) and roles (e.g. photosynthetic pathway) in ecosystem function. In this review, the PFT concept is traced from its origin in the early 1800s to its current use in regional and global dynamic vegetation models (DVMs). Special attention is given to the representation and parameterization of PFTs and to validation and benchmarking of predicted patterns of vegetation distribution in high-latitude ecosystems. These ecosystems are sensitive to changing climate and thus provide a useful test case for model-based simulations of past, current and future distribution of vegetation. Models that incorporate the PFT concept predict many of the emerging patterns of vegetation change in tundra and boreal forests, given known processes of tree mortality, treeline migration and shrub expansion. However, representation of above- and especially below-ground traits for specific PFTs continues to be problematic. Potential solutions include developing trait databases and replacing fixed parameters for PFTs with formulations based on trait co-variance and empirical trait-environment relationships. Surprisingly, despite being important to land-atmosphere interactions of carbon, water and energy, PFTs such as moss and lichen are largely absent from DVMs. Close collaboration among those involved in modelling with the disciplines of taxonomy, biogeography, ecology and remote sensing will be

  10. Using a Virtual Manipulative Environment to Support Students' Organizational Structuring of Volume Units

    Science.gov (United States)

    O'Dell, Jenna R.; Barrett, Jeffrey E.; Cullen, Craig J.; Rupnow, Theodore J.; Clements, Douglas H.; Sarama, Julie; Rutherford, George; Beck, Pamela S.

    2017-01-01

    In this study, we investigated how Grade 3 and 4 students' organizational structure for volume units develops through repeated experiences with a virtual manipulative for building prisms. Our data consist of taped clinical interviews within a micro-genetic experiment. We report on student strategy development using a virtual manipulative for…

  11. Adaptive Control Of Remote Manipulator

    Science.gov (United States)

    Seraji, Homayoun

    1989-01-01

    Robotic control system causes remote manipulator to follow closely reference trajectory in Cartesian reference frame in work space, without resort to computationally intensive mathematical model of robot dynamics and without knowledge of robot and load parameters. System, derived from linear multivariable theory, uses relatively simple feedforward and feedback controllers with model-reference adaptive control.

  12. Indicial tensor manipulation on MACSYMA

    International Nuclear Information System (INIS)

    Bogen, R.A.; Pavelle, R.

    1977-01-01

    A new computational tool for physical calculations is described. It is the first computer system capable of performing indicial tensor calculus (as opposed to component tensor calculus). It is now operational on the symbolic manipulation system MACSYMA. The authors outline the capabilities of the system and describe some of the physical problems considered as well as others being examined at this time. (Auth.)

  13. Manipulations of Totalitarian Nazi Architecture

    Science.gov (United States)

    Antoszczyszyn, Marek

    2017-10-01

    The paper takes under considerations controversies surrounding German architecture designed during Nazi period between 1933-45. This architecture is commonly criticized for being out of innovation, taste & elementary sense of beauty. Moreover, it has been consequently wiped out from architectural manuals, probably for its undoubted associations with the totalitarian system considered as the most maleficent in the whole history. But in the meantime the architecture of another totalitarian system which appeared to be not less sinister than Nazi one is not stigmatized with such verve. It is Socrealism architecture, developed especially in East Europe & reportedly containing lots of similarities with Nazi architecture. Socrealism totalitarian architecture was never condemned like Nazi one, probably due to politically manipulated propaganda that influenced postwar public opinion. This observation leads to reflection that maybe in the same propaganda way some values of Nazi architecture are still consciously dissembled in order to hide the fact that some rules used by Nazi German architects have been also consciously used after the war. Those are especially manipulations that allegedly Nazi architecture consisted of. The paper provides some definitions around totalitarian manipulations as well as ideological assumptions for their implementation. Finally, the register of confirmed manipulations is provided with use of photo case study.

  14. Mapping and Manipulating Facial Expression

    Science.gov (United States)

    Theobald, Barry-John; Matthews, Iain; Mangini, Michael; Spies, Jeffrey R.; Brick, Timothy R.; Cohn, Jeffrey F.; Boker, Steven M.

    2009-01-01

    Nonverbal visual cues accompany speech to supplement the meaning of spoken words, signify emotional state, indicate position in discourse, and provide back-channel feedback. This visual information includes head movements, facial expressions and body gestures. In this article we describe techniques for manipulating both verbal and nonverbal facial…

  15. MODULAR MANIPULATOR FOR ROBOTICS APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Joseph W. Geisinger, Ph.D.

    2001-07-31

    ARM Automation, Inc. is developing a framework of modular actuators that can address the DOE's wide range of robotics needs. The objective of this effort is to demonstrate the effectiveness of this technology by constructing a manipulator from these actuators within a glovebox for Automated Plutonium Processing (APP). At the end of the project, the system of actuators was used to construct several different manipulator configurations, which accommodate common glovebox tasks such as repackaging. The modular nature and quickconnects of this system simplify installation into ''hot'' boxes and any potential modifications or repair therein. This work focused on the development of self-contained robotic actuator modules including the embedded electronic controls for the purpose of building a manipulator system. Both of the actuators developed under this project contain the control electronics, sensors, motor, gear train, wiring, system communications and mechanical interfaces of a complete robotics servo device. Test actuators and accompanying DISC{trademark}s underwent validation testing at The University of Texas at Austin and ARM Automation, Inc. following final design and fabrication. The system also included custom links, an umbilical cord, an open architecture PC-based system controller, and operational software that permitted integration into a completely functional robotic manipulator system. The open architecture on which this system is based avoids proprietary interfaces and communication protocols which only serve to limit the capabilities and flexibility of automation equipment. The system was integrated and tested in the contractor's facility for intended performance and operations. The manipulator was tested using the full-scale equipment and process mock-ups. The project produced a practical and operational system including a quantitative evaluation of its performance and cost.

  16. MODULAR MANIPULATOR FOR ROBOTICS APPLICATIONS

    International Nuclear Information System (INIS)

    Geisinger, Joseph W. Ph.D.

    2001-01-01

    ARM Automation, Inc. is developing a FR-amework of modular actuators that can address the DOE's wide range of robotics needs. The objective of this effort is to demonstrate the effectiveness of this technology by constructing a manipulator FR-om these actuators within a glovebox for Automated Plutonium Processing (APP). At the end of the project, the system of actuators was used to construct several different manipulator configurations, which accommodate common glovebox tasks such as repackaging. The modular nature and quickconnects of this system simplify installation into ''hot'' boxes and any potential modifications or repair therein. This work focused on the development of self-contained robotic actuator modules including the embedded electronic controls for the purpose of building a manipulator system. Both of the actuators developed under this project contain the control electronics, sensors, motor, gear train, wiring, system communications and mechanical interfaces of a complete robotics servo device. Test actuators and accompanying DISC(trademark)s underwent validation testing at The University of Texas at Austin and ARM Automation, Inc. following final design and fabrication. The system also included custom links, an umbilical cord, an open architecture PC-based system controller, and operational software that permitted integration into a completely functional robotic manipulator system. The open architecture on which this system is based avoids proprietary interfaces and communication protocols which only serve to limit the capabilities and flexibility of automation equipment. The system was integrated and tested in the contractor's facility for intended performance and operations. The manipulator was tested using the full-scale equipment and process mock-ups. The project produced a practical and operational system including a quantitative evaluation of its performance and cost

  17. Acoustic manipulation of bacteria cells suspensions

    Science.gov (United States)

    GutiéRrez-Ramos, Salomé; Hoyos, Mauricio; Aider, Jean Luc; Ruiz, Carlos; Acoustofluidics Team Team; Soft; Bio Group Collaboration

    An acoustic contacless manipulation gives advantages in the exploration of the complex dynamics enviroment that active matter exhibits. Our works reports the control confinement and dispersion of Escherichia coliRP437-pZA3R-YFP suspensions (M9Glu-Ca) via acoustic levitation.The manipulation of the bacteria bath in a parallel plate resonator is achieved using the acoustic radiation force and the secondary radiation force. The primary radiation force generates levitation of the bacteria cells at the nodal plane of the ultrasonic standing wave generated inside the resonator. On the other side, secondary forces leads to the consolidation of stable aggregates. All the experiments were performed in the acoustic trap described, where we excite the emission plate with a continuous sinusoidal signal at a frequency in the order of MHz and a quartz slide as the reflector plate. In a typical experiment we observed that, before the input of the signal, the bacteria cells exhibit their typical run and tumble behavior and after the sound is turned on all of them displace towards the nodal plane, and instantaneously the aggregation begins in this region. CNRS French National Space Studies, CONACYT Mexico.

  18. Measuring Entrepreneurial Ecosystems

    NARCIS (Netherlands)

    Stam, F.C.

    How can entrepreneurial ecosystems and productive entrepreneurship can be traced empirically and how is entrepreneurship related to entrepreneurial ecosystems. The analyses in this chapter show the value of taking a systems view on the context of entrepreneurship. We measure entrepreneurial

  19. Coral reefs - Specialized ecosystems

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.

    This paper discusses briefly some aspects that characterize and differentiate coral reef ecosystems from other tropical marine ecosystems. A brief account on the resources that are extractable from coral reefs, their susceptibility to natural...

  20. Resilience to Changing Snow Depth in a Shrubland Ecosystem.

    Science.gov (United States)

    Loik, M. E.

    2008-12-01

    Snowfall is the dominant hydrologic input for high elevations and latitudes of the arid- and semi-arid western United States. Sierra Nevada snowpack provides numerous important services for California, but is vulnerable to anthropogenic forcing of the coupled ocean-atmosphere system. GCM and RCM scenarios envision reduced snowpack and earlier melt under a warmer climate, but how will these changes affect soil and plant water relations and ecosystem processes? And, how resilient will this ecosystem be to short- and long-term forcing of snow depth and melt timing? To address these questions, our experiments utilize large- scale, long-term roadside snow fences to manipulate snow depth and melt timing in eastern California, USA. Interannual snow depth averages 1344 mm with a CV of 48% (April 1, 1928-2008). Snow fences altered snow melt timing by up to 18 days in high-snowfall years, and affected short-term soil moisture pulses less in low- than medium- or high-snowfall years. Sublimation in this arid location accounted for about 2 mol m- 2 of water loss from the snowpack in 2005. Plant water potential increased after the ENSO winter of 2005 and stayed relatively constant for the following three years, even after the low snowfall of winter 2007. Over the long-term, changes in snow depth and melt timing have impacted cover or biomass of Achnatherum thurberianum, Elymus elemoides, and Purshia tridentata. Growth of adult conifers (Pinus jeffreyi and Pi. contorta) was not equally sensitive to snow depth. Thus, complex interactions between snow depth, soil water inputs, physiological processes, and population patterns help drive the resilience of this ecosystem to changes in snow depth and melt timing.

  1. Ecosystem classification, Chapter 2

    Science.gov (United States)

    M.J. Robin-Abbott; L.H. Pardo

    2011-01-01

    The ecosystem classification in this report is based on the ecoregions developed through the Commission for Environmental Cooperation (CEC) for North America (CEC 1997). Only ecosystems that occur in the United States are included. CEC ecoregions are described, with slight modifications, below (CEC 1997) and shown in Figures 2.1 and 2.2. We chose this ecosystem...

  2. On Man and Ecosystems.

    Science.gov (United States)

    Brookfield, Harold

    1982-01-01

    Distinctions between natural ecosystems and human ecosystems are misleading. Natural and social sciences can be integrated through the concept of a "human-use ecosystem," in which social scientists analyze the community, household, and individual, and natural scientists analyze the land. Includes a case study of St. Kitts. (KC)

  3. Global Ecosystem Restoration Index

    DEFF Research Database (Denmark)

    Fernandez, Miguel; Garcia, Monica; Fernandez, Nestor

    2015-01-01

    The Global ecosystem restoration index (GERI) is a composite index that integrates structural and functional aspects of the ecosystem restoration process. These elements are evaluated through a window that looks into a baseline for degraded ecosystems with the objective to assess restoration...

  4. Towards ecosystem accounting

    NARCIS (Netherlands)

    Duku, C.; Rathjens, H.; Zwart, S.J.; Hein, L.

    2015-01-01

    Ecosystem accounting is an emerging field that aims to provide a consistent approach to analysing environment-economy interactions. One of the specific features of ecosystem accounting is the distinction between the capacity and the flow of ecosystem services. Ecohydrological modelling to support

  5. Rights to ecosystem services

    NARCIS (Netherlands)

    Davidson, M.

    2014-01-01

    Ecosystem services are the benefits people obtain from ecosystems. Many of these services are provided outside the borders of the land where they are produced; this article investigates who is entitled to these non-excludable ecosystem services from two libertarian perspectives. Taking a

  6. Manipulators

    International Nuclear Information System (INIS)

    Papet, I.; Lune, P.; Pellerin, O.; Sapoval, M.; Brisse, H.; Clement, J.P.; Ribeiro, A.; Gomes, H.; Marcus, C.; Rehel, J.L.

    2005-01-01

    These two articles bring notions relative to the safety of procedures, specially in term of irradiation, they give information on different methods in order to reduce the radiation doses delivered to the patients, especially when the examinations concern children or young patients. (N.C.)

  7. Model Manipulation for End-User Modelers

    DEFF Research Database (Denmark)

    Acretoaie, Vlad

    , and transformations using their modeling notation and editor of choice. The VM* languages are implemented via a single execution engine, the VM* Runtime, built on top of the Henshin graph-based transformation engine. This approach combines the benefits of flexibility, maturity, and formality. To simplify model editor......End-user modelers are domain experts who create and use models as part of their work. They are typically not Software Engineers, and have little or no programming and meta-modeling experience. However, using model manipulation languages developed in the context of Model-Driven Engineering often...... requires such experience. These languages are therefore only used by a small subset of the modelers that could, in theory, benefit from them. The goals of this thesis are to substantiate this observation, introduce the concepts and tools required to overcome it, and provide empirical evidence in support...

  8. Application of model based control to robotic manipulators

    Science.gov (United States)

    Petrosky, Lyman J.; Oppenheim, Irving J.

    1988-01-01

    A robot that can duplicate humam motion capabilities in such activities as balancing, reaching, lifting, and moving has been built and tested. These capabilities are achieved through the use of real time Model-Based Control (MBC) techniques which have recently been demonstrated. MBC accounts for all manipulator inertial forces and provides stable manipulator motion control even at high speeds. To effectively demonstrate the unique capabilities of MBC, an experimental robotic manipulator was constructed, which stands upright, balancing on a two wheel base. The mathematical modeling of dynamics inherent in MBC permit the control system to perform functions that are impossible with conventional non-model based methods. These capabilities include: (1) Stable control at all speeds of operation; (2) Operations requiring dynamic stability such as balancing; (3) Detection and monitoring of applied forces without the use of load sensors; (4) Manipulator safing via detection of abnormal loads. The full potential of MBC has yet to be realized. The experiments performed for this research are only an indication of the potential applications. MBC has no inherent stability limitations and its range of applicability is limited only by the attainable sampling rate, modeling accuracy, and sensor resolution. Manipulators could be designed to operate at the highest speed mechanically attainable without being limited by control inadequacies. Manipulators capable of operating many times faster than current machines would certainly increase productivity for many tasks.

  9. Asymmetry in ecosystem responses to precipitation: Theory, observation and experimentation

    Science.gov (United States)

    Sala, O.; Gherardi, L.; Reichmann, L.; Peters, D.

    2017-12-01

    Ecosystem processes such as primary production respond to changes in precipitation that occur annually and at longer time scales. The questions guiding this presentation are whether ecosystem responses to wet and dry years are symmetrical. Is the increase in productivity in a wet year similar in absolute value to the decrease in productivity in a dry year following a wet year? Is the response to one dry or wet year similar tot response of several consecutive wet and dry years? Do all plant-functional groups respond in a similar way to changes in precipitation? To address the questions we explore the theory behind a potential asymmetry and report on experimental results. Analysis of the cost and benefits of plant responses to changes in precipitation support the idea asymmetrical responses because the threshold for abscising organs that have already been deployed should be higher than the threshold to deploy new organs. However, experiments in a desert grassland in New Mexico where we experimentally increased and decreased precipitation from one year to the next showed that the response was symmetrical. Another mechanism that may yield asymmetries is the productivity response to changes in precipitation is associated with the shape of the relationship between precipitation and productivity. Straight-line relationship may yield no asymmetries whereas a saturating or concave up relationship may result in different asymmetries. Here, we report results from an experiment that yielded concave down responses for grasses and concave up for shrubs. Finally, we report results from a 10-year experiment showing asymmetric responses of grasses and shrubs. Moreover, the magnitude of the sign of the responses changed with the time since the beginning of the precipitation manipulation.

  10. Modeling the manipulator and flipper pose effects on tip over stability of a tracked mobile manipulator

    CSIR Research Space (South Africa)

    Dube, C

    2011-11-01

    Full Text Available Mobile manipulators are used in a number of different applications such as bomb disposal, mining robotics, and search and rescue operations. These mobile manipulators are highly susceptible to tip over due to the motion of the manipulator...

  11. Contribution of trees and grasses to ecosystem fluxes of water, carbon, and energy throughout the seasons under different nutrient availability

    Science.gov (United States)

    El-Madany, T. S.; Migliavacca, M.; Perez-Priego, O.; Luo, Y.; Moreno, G.; Carrara, A.; Kolle, O.; Reichstein, M.

    2017-12-01

    In semi-arid savanna type ecosystems, the carbon and water cycle are closely related to each other. Water availability is the main driver for the development and phenology of the vegetation, especially for annual plants. Depending on tree density, nutrient availability and species the contribution of the tree- and the herbaceous layer to ecosystem fluxes can vary substantially. We present data from an ecosystem scale nutrient manipulation experiment within a Mediterranean savanna type ecosystem which is used for cattle. The footprint areas of two out of three ecosystem eddy co-variance (EC) towers were fertilized with nitrogen (NT) and nitrogen plus phosphorous (NPT) while the third one served as the control tower (CT). At each ecosystem EC-tower an additional herbaceous layer tower was installed that only sampled fluxes from the herbaceous layer. Under certain assumptions flux differences between the ecosystem EC and the herbaceous layer EC systems can be considered as the contribution of the trees to the ecosystem fluxes. Based on phenology of the herbaceous layer estimated through green-chromatic-coordinates from digital imagery the year was separated into spring, senescence, regreening, and winter. The focus of the analysis is (i) the evaluation of the method and how it works throughout the different seasons and (ii) the quantification of the contribution of trees and grasses to ecosystem fluxes of water, carbon, and energy under different environmental conditions and nutrient stoichiometry. The contribution of the trees to total ecosystem fluxes is variable in time. Especially, during the beginning of the senescence period high evapotranspiration rates and largest carbon uptake are measured while the contribution to sensible heat fluxes is largest during the end of the summer. During the regreening and winter the contribution of ET is relatively constant around 0.25 mm d-1. During the peak of the greenness ET and carbon flux of the herbaceous EC tower are

  12. Ecosystem services in ECOCLIM

    DEFF Research Database (Denmark)

    Sørensen, Lise Lotte; Boegh, Eva; Bendtsen, J

    that actions initiated to reduce anthropogenic GHG emissions are sustainable and not destructive to existing ecosystem services. Therefore it is important to address i.e. land use change in relation to the regulating services of the ecosystems, such as carbon sequestration and climate regulation. At present...... a thorough understanding of the ecosystem processes controlling the uptake or emissions of GHG is fundamental. Here we present ECOCLIM in the context of ecosystem services and the experimental studies within ECOCLIM which will lead to an enhanced understanding of Danish ecosystems....

  13. Adaptive hybrid control of manipulators

    Science.gov (United States)

    Seraji, H.

    1987-01-01

    Simple methods for the design of adaptive force and position controllers for robot manipulators within the hybrid control architecuture is presented. The force controller is composed of an adaptive PID feedback controller, an auxiliary signal and a force feedforward term, and it achieves tracking of desired force setpoints in the constraint directions. The position controller consists of adaptive feedback and feedforward controllers and an auxiliary signal, and it accomplishes tracking of desired position trajectories in the free directions. The controllers are capable of compensating for dynamic cross-couplings that exist between the position and force control loops in the hybrid control architecture. The adaptive controllers do not require knowledge of the complex dynamic model or parameter values of the manipulator or the environment. The proposed control schemes are computationally fast and suitable for implementation in on-line control with high sampling rates.

  14. Master-slave type manipulator

    International Nuclear Information System (INIS)

    Haaker, L.W.; Jelatis, D.G.

    1979-01-01

    Remote control manipulator of the master-slave type for carrying out work on the other side of a shield wall. This appliance allows a Y movement relative displacement, the function of which is to extend the range of the manipulator towards the front and also to facilitate its installation, the lateral rotation or inclination of the slave arm in relation to the master arm, and the Z movement extension through which the length of the slave arm is increased in comparison with that of the master arm. Devices have been developed which transform the linear movements into rotational movements to enable these movements to be transmitted through rotational seal fittings capable of ensuring the safety of the separation between the operator's environment and that in the work area. Particular improvements have been made to the handles, handle seals, pincer mechanisms, etc [fr

  15. Genetic manipulation of Francisella tularensis

    Directory of Open Access Journals (Sweden)

    Xhavit eZogaj

    2011-01-01

    Full Text Available Francisella tularensis is a facultative intracellular pathogen that causes the disease tularemia. F. tularensis subsp. tularensis causes the most severe disease in humans and has been classified as a select A agent and potential bioweapon. There is currently no vaccine approved for human use, making genetic manipulation of this organism critical to unraveling the genetic basis of pathogenesis and developing countermeasures against tularemia. The development of genetic techniques applicable to F. tularensis have lagged behind those routinely used for other bacteria, primarily due to lack of research and the restricted nature of the biocontainment required for studying this pathogen. However, in recent years, genetic techniques, such as transposon mutagenesis and targeted gene disruption, have been developed, that have had a dramatic impact on our understanding of the genetic basis of F. tularensis virulence. In this review, we describe some of the methods developed for genetic manipulation of F. tularensis.

  16. Viruses manipulate the marine environment.

    Science.gov (United States)

    Rohwer, Forest; Thurber, Rebecca Vega

    2009-05-14

    Marine viruses affect Bacteria, Archaea and eukaryotic organisms and are major components of the marine food web. Most studies have focused on their role as predators and parasites, but many of the interactions between marine viruses and their hosts are much more complicated. A series of recent studies has shown that viruses have the ability to manipulate the life histories and evolution of their hosts in remarkable ways, challenging our understanding of this almost invisible world.

  17. List manipulation in Turbo Prolog

    Directory of Open Access Journals (Sweden)

    V.Cotelea

    1995-06-01

    Full Text Available The present paper is concerned with list processing in Turbo Prolog language. It doesn't claim to be an exhaustive description of operations which can be performed upon lists. Nevertheless adduced programs are most representative, more or less known to specialists in logic programming domain. By means of examples are explained the list manipulation techniques, use of recursion, declarative comparison of predicates, analysis and fixation of acceptable prototypes and some problems of predicates' inconsistency. Index terms. Prolog, list, recursion.

  18. Manipulation of Biofilm Microbial Ecology

    Energy Technology Data Exchange (ETDEWEB)

    White, D.C.; Palmer, R.J., Jr.; Zinn, M.; Smith, C.A.; Burkhalter, R.; Macnaughton, S.J.; Whitaker, K.W.; Kirkegaard, R.D.

    1998-08-15

    The biofilm mode of growth provides such significant advantages to the members of the consortium that most organisms in important habitats are found in biofilms. The study of factors that allow manipulation of biofilm microbes in the biofilm growth state requires that reproducible biofilms be generated. The most effective monitoring of biofilm formation, succession and desaturation is with on-line monitoring of microbial biofilms with flowcell for direct observation. The biofilm growth state incorporates a second important factor, the heterogeneity in distribution in time and space of the component members of the biofilm consortium. This heterogeneity is reflected not only in the cellular distribution but in the metabolic activity within a population of cells. Activity and cellular distribution can be mapped in four dimensions with confocal microscopy, and function can be ascertained by genetically manipulated reporter functions for specific genes or by vital stains. The methodology for understanding the microbial ecology of biofilms is now much more readily available and the capacity to manipulate biofilms is becoming an important feature of biotechnology.

  19. [Standardizing the manipulation procedure of acupuncture-moxibustion, reinforcing the training of' clinical skill: learning experience of Acupuncture-moxibustion Clinical Skills Training: Chapter of Commonly Used Needling and Moxibustion Techniques].

    Science.gov (United States)

    Tian, Hongfang; Yang, Chao; Tang, Jie; Qin, Qiuguo; Zhao, Mingwen; Zhao, Jiping

    2015-07-01

    The book Acupuncture-moxibustion Clinical Skills Training is one of "Twelfth Five-Year Plan" in novative teaching materials, which is published by People's Medical Publishing House. Through learning the first half of the book commonly used needling and moxibustion techniques, it is realized that the selection of book content is reasonable and much attention is paid to needling and moxibustion techniques; the chapter arrangement is well-organized, and the form is novel, which is concise and intuitive; for every technique, great attention is paid to standardize the manipulation procedure and clarify the technique key, simultaneously the safety of acupuncture and moxibustion is also emphasized. The characteristics of the book, including innovativeness, practicability, are highlighted, and it greatly helps to improve students' clinical skills and examination ability.

  20. Particle Manipulation Methods in Droplet Microfluidics.

    Science.gov (United States)

    Tenje, Maria; Fornell, Anna; Ohlin, Mathias; Nilsson, Johan

    2018-02-06

    This Feature describes the different particle manipulation techniques available in the droplet microfluidics toolbox to handle particles encapsulated inside droplets and to manipulate whole droplets. We address the advantages and disadvantages of the different techniques to guide new users.

  1. Physics Based Vision Systems for Robotic Manipulation

    Data.gov (United States)

    National Aeronautics and Space Administration — With the increase of robotic manipulation tasks (TA4.3), specifically dexterous manipulation tasks (TA4.3.2), more advanced computer vision algorithms will be...

  2. Picture perfect: The direct effect of manipulated Instagram photos on body image in adolescent girls

    OpenAIRE

    Kleemans, M.; Daalmans, S.; Carbaat, I.; Anschutz, D.J.

    2018-01-01

    This study investigates the effect of manipulated Instagram photos on adolescent girls' body image, and whether social comparison tendency moderates this relation. A between-subject experiment was conducted in which 144 girls (14-18 years old) were randomly exposed to either original or manipulated (retouched and reshaped) Instagram selfies. Results showed that exposure to manipulated Instagram photos directly led to lower body image. Especially, girls with higher social comparison tendencies...

  3. Embodied cognition, abstract concepts, and body manipulation

    Directory of Open Access Journals (Sweden)

    Katinka eDijkstra

    2014-08-01

    Full Text Available Current approaches on cognition hold that concrete concepts are grounded in concrete experiences. There is no consensus, however, as to whether this is equally true for abstract concepts. In this review we discuss how the body might be involved in understanding abstract concepts through metaphor activation. Substantial research has been conducted on the activation of common orientational metaphors with bodily manipulations, such as ‘power is up’ and ‘more is up’ representations. We will focus on the political metaphor that has a more complex association between the concept and the concrete domain. However, the outcomes of studies on this political metaphor have not always been consistent, possibly because the experimental manipulation was not implicit enough. The inclusion of new technological devices in this area of research, such as the Wii Balance Board, seems promising in order to assess the groundedness of abstract conceptual spatial metaphors in an implicit manner. This may aid further research to effectively demonstrate the interrelatedness between the body and more abstract representations.

  4. Mechanical Design of a Manipulation System for Unmanned Aerial Vehicles

    NARCIS (Netherlands)

    Keemink, A.Q.L.; Fumagalli, M.; Stramigioli, S.; Carloni, R.

    In this paper, we present the mechanical design and modeling of a manipulation system for unmanned aerial vehicles, which have to physically interact with environments and perform ultrasonic non-destructive testing experiments and other versatile tasks at unreachable locations for humans. The

  5. Bringing Stories to Life: Integrating Literature and Math Manipulatives

    Science.gov (United States)

    Larson, Lotta C.; Rumsey, Chepina

    2018-01-01

    This Teaching Tip describes the use of children's literature to help second-grade students meet Common Core State Standards for English Language Arts and for Mathematics. During a shared reading experience, students used manipulatives to represent plot and characters while demonstrating mathematical reasoning. The article offers instructional…

  6. The left fusiform gyrus hosts trisensory representations of manipulable objects

    DEFF Research Database (Denmark)

    Kassuba, Tanja; Klinge, Corinna; Hölig, Cordula

    2011-01-01

    During object manipulation the brain integrates the visual, auditory, and haptic experience of an object into a unified percept. Previous brain imaging studies have implicated for instance the dorsal part of the lateral occipital complex in visuo-tactile and the posterior superior temporal sulcus...

  7. Decomposition performance of animals as an indicator of stress acting on beech-forest ecosystems - microcosmos experiments with carbon-14-labelled litter components

    International Nuclear Information System (INIS)

    Schaefer, M.; Wolters, V.

    1988-01-01

    The effect of acid rain and heavy metals on the biotic interactions in the soil of beech forest with mull, must, and limed must was investigated with the aid of close-to-nature microcosmos systems. Parameters made use of were the decomposition of carbon-14-labelled litter components and the turnover of the microflora in C, N, and P. As the results show, increased proton uptake will bear on rearly every stage of the decomposition process in mull soils. As a result, there may be litter accumulation on the ground and first signs of humus disintegration in the mineral soil of mull soils. A direct relation between the acidity of the environment and the extent of decomposition inhibition does not exist. Despite wide-ranging impairment of edaphic animals, the activity of the ground fauna still is to be considered as the most important buffer system of soils rich in bases. Acidic condition of the beech forest soils with the humus form 'must' led to drastic inhibition of litter decomposition, to a change of the effect of edaphic animals, and to an increase in N mineralization. The grazing animals frequently aggravate the decomposition inhibition resulting from acid precipitation. The comparision of the decomposition process in a soil containing must as compared to one containing mull showed acidic soils to be on a lower biological buffer level than soils rich in bases. The main buffer capacity of acidic soils lies in the microflora, which is adapted to sudden increases in acidity and which recovers quickly. In the opinion of the authors, simple liming is not enough to increase the long-term biogenic stability of a forest ecosystem. A stabilizing effect of the fauna, for instance on nitrogen storage, is possible only if forest care measuries are carried out, for instance careful loosening of the mineral soil, which will attract earthworm species penetrating deeply into the soil. (orig./MG) With 12 refs., 6 figs [de

  8. Global Energy-Optimal Redundancy Resolution of Hydraulic Manipulators: Experimental Results for a Forestry Manipulator

    Directory of Open Access Journals (Sweden)

    Jarmo Nurmi

    2017-05-01

    Full Text Available This paper addresses the energy-inefficiency problem of four-degrees-of-freedom (4-DOF hydraulic manipulators through redundancy resolution in robotic closed-loop controlled applications. Because conventional methods typically are local and have poor performance for resolving redundancy with respect to minimum hydraulic energy consumption, global energy-optimal redundancy resolution is proposed at the valve-controlled actuator and hydraulic power system interaction level. The energy consumption of the widely popular valve-controlled load-sensing (LS and constant-pressure (CP systems is effectively minimised through cost functions formulated in a discrete-time dynamic programming (DP approach with minimum state representation. A prescribed end-effector path and important actuator constraints at the position, velocity and acceleration levels are also satisfied in the solution. Extensive field experiments performed on a forestry hydraulic manipulator demonstrate the performance of the proposed solution. Approximately 15–30% greater hydraulic energy consumption was observed with the conventional methods in the LS and CP systems. These results encourage energy-optimal redundancy resolution in future robotic applications of hydraulic manipulators.

  9. Aggregated filter-feeding consumers alter nutrient limitation: consequences for ecosystem and community dynamics.

    Science.gov (United States)

    Atkinson, Carla L; Vaughn, Caryn C; Forshay, Kenneth J; Cooper, Joshua T

    2013-06-01

    Nutrient cycling is a key process linking organisms in ecosystems. This is especially apparent in stream environments in which nutrients are taken up readily and cycled through the system in a downstream trajectory. Ecological stoichiometry predicts that biogeochemical cycles of different elements are interdependent because the organisms that drive these cycles require fixed ratios of nutrients. There is growing recognition that animals play an important role in biogeochemical cycling across ecosystems. In particular, dense aggregations of consumers can create biogeochemical hotspots in aquatic ecosystems via nutrient translocation. We predicted that filter-feeding freshwater mussels, which occur as speciose, high-biomass aggregates, would create biogeochemical hotspots in streams by altering nutrient limitation and algal dynamics. In a field study, we manipulated nitrogen and phosphorus using nutrient-diffusing substrates in areas with high and low mussel abundance, recorded algal growth and community composition, and determined in situ mussel excretion stoichiometry at 18 sites in three rivers (Kiamichi, Little, and Mountain Fork Rivers, south-central United States). Our results indicate that mussels greatly influence ecosystem processes by modifying the nutrients that limit primary productivity. Sites without mussels were N-limited with -26% higher relative abundances of N-fixing blue-green algae, while sites with high mussel densities were co-limited (N and P) and dominated by diatoms. These results corroborated the results of our excretion experiments; our path analysis indicated that mussel excretion has a strong influence on stream water column N:P. Due to the high N:P of mussel excretion, strict N-limitation was alleviated, and the system switched to being co-limited by both N and P. This shows that translocation of nutrients by mussel aggregations is important to nutrient dynamics and algal species composition in these rivers. Our study highlights the

  10. Electrokinetic Phenomena in Chemically Manipulated Environments

    Science.gov (United States)

    Nery Azevedo, Rodrigo

    Suspended particles are integral part of many systems and engineering technologies. They can be found in the form of colloidal suspensions, emulsions, polymer precursor solutions, and in biological materials such as blood. The miniaturization of new technologies and the advent of microfludics has made the manipulation of suspended particles in the microscale particularly important for a variety of fields. The ability to easily impart complex chemical environments to suspensions in microfluidic devices enables us to characterize these systems, modify their properties and drive their motion. Nonetheless, precise manipulation of the chemistry surrounding suspended particles has been particularly difficult up until recently. This thesis dissertation shows how microfluidic devices integrated with hydrogel membranes can be used to control the chemical environment of suspended particles for a variety of studies and practical applications. First, I demonstrate how particles move diffusiophoretically under ionic surfactant gradients. Diffusiophoresis, the motion of particles under concentration gradients, has been known for several decades but it has rarely been studied experimentally outside the context of simple electrolytes. Here, we show that diffusiophoresis in ionic surfactants below the CMC can be understood in terms of the classic theory for electrolytes. Above the CMC, however, the drive for diffsuiophoresis is significantly diminished due to a large drop in the change in chemical potential with added solute. Next, I show that gradients of dipolar molecules such a zwitterions can drive diffusiophoresis. I derive the diffusiophoretic migration of particles under gradients of dipolar molecules. This theory is backed up by experiments which reveal that, in such systems, particle velocities are directly proportional to the imposed gradient but do not scale with the inverse of the local concentration, as occurs under electrolyte gradients. Furthermore, I show that the

  11. An evolutionary resolution of manipulation conflict.

    Science.gov (United States)

    González-Forero, Mauricio

    2014-07-01

    Individuals can manipulate the behavior of social partners. However, manipulation may conflict with the fitness interests of the manipulated individuals. Manipulated individuals can then be favored to resist manipulation, possibly reducing or eliminating the manipulated behavior in the long run. I use a mathematical model to show that conflicts where manipulation and resistance coevolve can disappear as a result of the coevolutionary process. I find that while manipulated individuals are selected to resist, they can simultaneously be favored to express the manipulated behavior at higher efficiency (i.e., providing increasing fitness effects to recipients of the manipulated behavior). Efficiency can increase to a point at which selection for resistance disappears. This process yields an efficient social behavior that is induced by social partners, and over which the inducing and induced individuals are no longer in conflict. A necessary factor is costly inefficiency. I develop the model to address the evolution of advanced eusociality via maternal manipulation (AEMM). The model predicts AEMM to be particularly likely in taxa with ancestrally imperfect resistance to maternal manipulation. Costly inefficiency occurs if the cost of delayed dispersal is larger than the benefit of exploiting the maternal patch. I discuss broader implications of the process. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  12. Using Manipulatives to Teach Elementary Mathematics

    Science.gov (United States)

    Boggan, Matthew; Harper, Sallie; Whitmire, Anna

    2010-01-01

    The purpose of this paper is to explain the importance and benefits of math manipulatives. For decades, the National Council of Teachers of Mathematics has encouraged school districts nationwide to use manipulatives in mathematical instruction. The value of manipulatives has been recognized for many years, but some teachers are reluctant to use…

  13. Contrasting response to nutrient manipulation in Arctic mesocosms are reproduced by a minimum microbial food web model.

    Science.gov (United States)

    Larsen, Aud; Egge, Jorun K; Nejstgaard, Jens C; Di Capua, Iole; Thyrhaug, Runar; Bratbak, Gunnar; Thingstad, T Frede

    2015-03-01

    A minimum mathematical model of the marine pelagic microbial food web has previously shown to be able to reproduce central aspects of observed system response to different bottom-up manipulations in a mesocosm experiment Microbial Ecosystem Dynamics (MEDEA) in Danish waters. In this study, we apply this model to two mesocosm experiments (Polar Aquatic Microbial Ecology (PAME)-I and PAME-II) conducted at the Arctic location Kongsfjorden, Svalbard. The different responses of the microbial community to similar nutrient manipulation in the three mesocosm experiments may be described as diatom-dominated (MEDEA), bacteria-dominated (PAME-I), and flagellated-dominated (PAME-II). When allowing ciliates to be able to feed on small diatoms, the model describing the diatom-dominated MEDEA experiment give a bacteria-dominated response as observed in PAME I in which the diatom community comprised almost exclusively small-sized cells. Introducing a high initial mesozooplankton stock as observed in PAME-II, the model gives a flagellate-dominated response in accordance with the observed response also of this experiment. The ability of the model originally developed for temperate waters to reproduce population dynamics in a 10°C colder Arctic fjord, does not support the existence of important shifts in population balances over this temperature range. Rather, it suggests a quite resilient microbial food web when adapted to in situ temperature. The sensitivity of the model response to its mesozooplankton component suggests, however, that the seasonal vertical migration of Arctic copepods may be a strong forcing factor on Arctic microbial food webs.

  14. Ecosystem-based management and the wealth of ecosystems

    OpenAIRE

    Yun, Seong Do; Hutniczak, Barbara; Abbott, Joshua K.; Fenichel, Eli P.

    2017-01-01

    Ecosystems store vast quantities of wealth, but difficulties measuring wealth held in ecosystems prevent its inclusion in accounting systems. Ecosystem-based management endeavors to manage ecosystems holistically. However, ecosystem-based management lacks headline indicators to evaluate performance. We unify the inclusive wealth and ecosystem-based management paradigms, allowing apples-to-apples comparisons between the wealth of the ecosystem and other forms of wealth, while providing a headl...

  15. Acoustic levitation and manipulation for space applications

    Science.gov (United States)

    Wang, T. G.

    1979-01-01

    A wide spectrum of experiments to be performed in space in a microgravity environment require levitation and manipulation of liquid or molten samples. A novel acoustic method has been developed at JPL for controlling liquid samples without physical contacts. This method utilizes the static pressure generated by three orthogonal acoustic standing waves excited within an enclosure. Furthermore, this method will allow the sample to be rotated and/or oscillated by modifying the phase angles and/or the amplitude of the acoustic field. This technique has been proven both in our laboratory and in a microgravity environment provided by KC-135 flights. Samples placed within our chamber driven at (1,0,0), (0,1,0), and (0,0,1), modes were indeed levitated, rotated, and oscillated.

  16. Manipulating bubbles with secondary Bjerknes forces

    Energy Technology Data Exchange (ETDEWEB)

    Lanoy, Maxime [Institut Langevin, ESPCI ParisTech, CNRS (UMR 7587), PSL Research University, 1 rue Jussieu, 75005 Paris (France); Laboratoire Matière et Systèmes Complexes, Université Paris-Diderot, CNRS (UMR 7057), 10 rue Alice Domon et Léonie Duquet, 75013 Paris (France); Derec, Caroline; Leroy, Valentin [Laboratoire Matière et Systèmes Complexes, Université Paris-Diderot, CNRS (UMR 7057), 10 rue Alice Domon et Léonie Duquet, 75013 Paris (France); Tourin, Arnaud [Institut Langevin, ESPCI ParisTech, CNRS (UMR 7587), PSL Research University, 1 rue Jussieu, 75005 Paris (France)

    2015-11-23

    Gas bubbles in a sound field are submitted to a radiative force, known as the secondary Bjerknes force. We propose an original experimental setup that allows us to investigate in detail this force between two bubbles, as a function of the sonication frequency, as well as the bubbles radii and distance. We report the observation of both attractive and, more interestingly, repulsive Bjerknes force, when the two bubbles are driven in antiphase. Our experiments show the importance of taking multiple scatterings into account, which leads to a strong acoustic coupling of the bubbles when their radii are similar. Our setup demonstrates the accuracy of secondary Bjerknes forces for attracting or repealing a bubble, and could lead to new acoustic tools for noncontact manipulation in microfluidic devices.

  17. Manipulating bubbles with secondary Bjerknes forces

    International Nuclear Information System (INIS)

    Lanoy, Maxime; Derec, Caroline; Leroy, Valentin; Tourin, Arnaud

    2015-01-01

    Gas bubbles in a sound field are submitted to a radiative force, known as the secondary Bjerknes force. We propose an original experimental setup that allows us to investigate in detail this force between two bubbles, as a function of the sonication frequency, as well as the bubbles radii and distance. We report the observation of both attractive and, more interestingly, repulsive Bjerknes force, when the two bubbles are driven in antiphase. Our experiments show the importance of taking multiple scatterings into account, which leads to a strong acoustic coupling of the bubbles when their radii are similar. Our setup demonstrates the accuracy of secondary Bjerknes forces for attracting or repealing a bubble, and could lead to new acoustic tools for noncontact manipulation in microfluidic devices

  18. Precision Spectral Manipulation: A Demonstration Using a Coherent Optical Memory

    Directory of Open Access Journals (Sweden)

    B. M. Sparkes

    2012-06-01

    Full Text Available The ability to coherently spectrally manipulate quantum information has the potential to improve qubit rates across quantum channels and find applications in optical quantum computing. In this paper, we present experiments that use a multielement solenoid combined with the three-level gradient echo memory scheme to perform precision spectral manipulation of optical pulses. These operations include separate bandwidth and frequency manipulation with precision down to tens of kHz, spectral filtering of up to three separate frequency components, as well as time-delayed interference between pulses with both the same, and different, frequencies. If applied in a quantum information network, these operations would enable frequency-based multiplexing of qubits.

  19. Interpersonal relationship manipulation at a personal level

    Directory of Open Access Journals (Sweden)

    Andreja Hribernik

    2010-12-01

    Full Text Available Manipulation is not unknown or strange to any of us. We have all experienced it, or perhaps even practiced it. It is wrong not to recognize it, to find excuses for it, and, above all, it is wrong not to decide to change one’s behaviour. Long-lasting use of manipulation leaves consequences on all the parties involved: the victim, the observer and the perpetrator. Manipulation is a relation between persons which does not consider the needs of everybody involved. It means exploitation and misleading, inhumane and unethical behaviour on the part of the manipulator, which he uses in order gain success, self-confirmation and to achieve his goals. In the act of manipulation personal boundaries of the other person are violated since the manipulator enforces his dominance and subjectedness of the victim. The manipulator invades the victim’s personal integrity, limiting their potential. He isolates, controls and intimidates them; by devises a system to catch the victims, to entangle them in his net and suck them up like a spider. If the manipulation is very successful, the other person does not recognize it as such; they consider themselves happy to be cooperating with the manipulator, as they identify his goals as their own. Therefore, the manipulator can be said to have stolen the manipulated person’s soul.

  20. Picture perfect: The direct effect of manipulated Instagram photos on body image in adolescent girls

    NARCIS (Netherlands)

    Kleemans, M.; Daalmans, S.; Carbaat, I.; Anschutz, D.J.

    2018-01-01

    This study investigates the effect of manipulated Instagram photos on adolescent girls' body image, and whether social comparison tendency moderates this relation. A between-subject experiment was conducted in which 144 girls (14-18 years old) were randomly exposed to either original or manipulated

  1. Preliminary evaluation of the Accident Response Mobile Manipulation System for accident site salvage operations

    International Nuclear Information System (INIS)

    Trujillo, J.M.; Morse, W.D.; Jones, D.P.

    1994-01-01

    This paper describes and evaluates operational experiences with the Accident Response Mobile Manipulation System (ARMMS) during simulated accident site salvage operations which might involve nuclear weapons. The ARMMS is based upon a teleoperated mobility platform with two Schilling Titan 7F Manipulators

  2. THE BEAR BROOK WATERSHED MANIPULATION PROJECT: WATERSHED SCIENCE IN A POLICY PERSPECTIVE

    Science.gov (United States)

    The Bear Brook Watershed Manipulation in Maine is a paired watershed experiment. Monitoring of the paired catchments (East Bear Brook - reference; West Bear Brook - experimental) began in early 1987. Chemical manipulation of West Bear Brook catchment began in November 1989. Proce...

  3. A Comparison of Concrete and Virtual Manipulative Use in Third- and Fourth-Grade Mathematics

    Science.gov (United States)

    Burns, Barbara A.; Hamm, Ellen M.

    2011-01-01

    The primary purpose of this classroom experiment was to examine the effectiveness of concrete (hands-on) manipulatives as compared with virtual (computer-based) manipulatives on student review of fraction concepts in third grade and introduction of symmetry concepts in fourth grade. A pretest-posttest design was employed with a sample of 91…

  4. Integration and Assessment of Multiple Mobile Manipulators in a Real-World Industrial Production Facility

    DEFF Research Database (Denmark)

    Bøgh, Simon; Schou, Casper; Rühr, Thomas

    2014-01-01

    This paper presents a large-scale research experiment carried out within the TAPAS project, where multiple mobile manipulators were integrated and assessed in an industrial context. We consider an industrial scenario in which mobile manipulators naturally extend automation of logistic tasks towar...

  5. Deception studies manipulating centrally acting performance modifiers: a review.

    Science.gov (United States)

    Williams, Emily L; Jones, Hollie S; Sparks, Sandy; Marchant, David C; Micklewright, Dominic; McNaughton, Lars R

    2014-07-01

    Athletes anticipatorily set and continuously adjust pacing strategies before and during events to produce optimal performance. Self-regulation ensures maximal effort is exerted in correspondence with the end point of exercise, while preventing physiological changes that are detrimental and disruptive to homeostatic control. The integration of feedforward and feedback information, together with the proposed brain's performance modifiers is said to be fundamental to this anticipatory and continuous regulation of exercise. The manipulation of central, regulatory internal and external stimuli has been a key focus within deception research, attempting to influence the self-regulation of exercise and induce improvements in performance. Methods of manipulating performance modifiers such as unknown task end point, deceived duration or intensity feedback, self-belief, or previous experience create a challenge within research, as although they contextualize theoretical propositions, there are few ecological and practical approaches which integrate theory with practice. In addition, the different methods and measures demonstrated in manipulation studies have produced inconsistent results. This review examines and critically evaluates the current methods of how specific centrally controlled performance modifiers have been manipulated, within previous deception studies. From the 31 studies reviewed, 10 reported positive effects on performance, encouraging future investigations to explore the mechanisms responsible for influencing pacing and consequently how deceptive approaches can further facilitate performance. The review acts to discuss the use of expectation manipulation not only to examine which methods of deception are successful in facilitating performance but also to understand further the key components used in the regulation of exercise and performance.

  6. Genetic manipulation of Methanosarcina spp.

    Directory of Open Access Journals (Sweden)

    Petra Regine Adelheid Kohler

    2012-07-01

    Full Text Available The discovery of the third domain of life, the Archaea, is one of the most exciting findings of the last century. These remarkable prokaryotes are well known for their adaptations to extreme environments; however, Archaea have also conquered moderate environments. Many of the archaeal biochemical processes, such as methane production, are unique in nature and therefore of great scientific interest. Although formerly restricted to biochemical and physiological studies, sophisticated systems for genetic manipulation have been developed during the last two decades for methanogenic archaea, halophilic archaea and thermophilic, sulfur-metabolizing archaea. The availability of these tools has allowed for more complete studies of archaeal physiology and metabolism and most importantly provides the basis for the investigation of gene expression, regulation and function. In this review we provide an overview of methods for genetic manipulation of Methanosarcina spp., a group of methanogenic archaea that are key players in the global carbon cycle and which can be found in a variety of anaerobic environments.

  7. Covariance Manipulation for Conjunction Assessment

    Science.gov (United States)

    Hejduk, M. D.

    2016-01-01

    The manipulation of space object covariances to try to provide additional or improved information to conjunction risk assessment is not an uncommon practice. Types of manipulation include fabricating a covariance when it is missing or unreliable to force the probability of collision (Pc) to a maximum value ('PcMax'), scaling a covariance to try to improve its realism or see the effect of covariance volatility on the calculated Pc, and constructing the equivalent of an epoch covariance at a convenient future point in the event ('covariance forecasting'). In bringing these methods to bear for Conjunction Assessment (CA) operations, however, some do not remain fully consistent with best practices for conducting risk management, some seem to be of relatively low utility, and some require additional information before they can contribute fully to risk analysis. This study describes some basic principles of modern risk management (following the Kaplan construct) and then examines the PcMax and covariance forecasting paradigms for alignment with these principles; it then further examines the expected utility of these methods in the modern CA framework. Both paradigms are found to be not without utility, but only in situations that are somewhat carefully circumscribed.

  8. Seasonal variations in methane fluxes in response to summer warming and leaf litter addition in a subarctic heath ecosystem

    Science.gov (United States)

    Pedersen, Emily Pickering; Elberling, Bo; Michelsen, Anders

    2017-08-01

    Methane (CH4) is a powerful greenhouse gas controlled by both biotic and abiotic processes. Few studies have investigated CH4 fluxes in subarctic heath ecosystems, and climate change-induced shifts in CH4 flux and the overall carbon budget are therefore largely unknown. Hence, there is an urgent need for long-term in situ experiments allowing for the study of ecosystem processes over time scales relevant to environmental change. Here we present in situ CH4 and CO2 flux measurements from a wet heath ecosystem in northern Sweden subjected to 16 years of manipulations, including summer warming with open-top chambers, birch leaf litter addition, and the combination thereof. Throughout the snow-free season, the ecosystem was a net sink of CH4 and CO2 (CH4 -0.27 mg C m-2 d-1; net ecosystem exchange -1827 mg C m-2 d-1), with highest CH4 uptake rates (-0.70 mg C m-2 d-1) during fall. Warming enhanced net CO2 flux, while net CH4 flux was governed by soil moisture. Litter addition and the combination with warming significantly increased CH4 uptake rates, explained by a pronounced soil drying effect of up to 32% relative to ambient conditions. Both warming and litter addition also increased the seasonal average concentration of dissolved organic carbon in the soil. The site was a carbon sink with a net uptake of 60 g C m-2 over the snow-free season. However, warming reduced net carbon uptake by 77%, suggesting that this ecosystem type might shift from snow-free season sink to source with increasing summer temperatures.

  9. BUSINESS ECOSYSTEMS VS BUSINESS DIGITAL ECOSYSTEMS

    Directory of Open Access Journals (Sweden)

    Marinela Lazarica

    2006-05-01

    Full Text Available E-business is often described as the small organisations’ gateway to global business and markets. The adoption of Internet-based technologies for e-business is a continuous process, with sequential steps of evolution. The latter step in the adoption of Internet-based technologies for business, where the business services and the software components are supported by a pervasive software environment, which shows an evolutionary and self-organising behaviour are named digital business ecosystems. The digital business ecosystems are characterized by intelligent software components and services, knowledge transfer, interactive training frameworks and integration of business processes and e-government models.

  10. Laser manipulation of atomic and molecular flows

    Science.gov (United States)

    Lilly, Taylor C.

    The continuing advance of laser technology enables a range of broadly applicable, laser-based flow manipulation techniques. The characteristics of these laser-based flow manipulations suggest that they may augment, or be superior to, such traditional electro-mechanical methods as ionic flow control, shock tubes, and small scale wind tunnels. In this study, methodology was developed for investigating laser flow manipulation techniques, and testing their feasibility for a number of aerospace, basic physics, and micro technology applications. Theories for laser-atom and laser-molecule interactions have been under development since the advent of laser technology. The theories have yet to be adequately integrated into kinetic flow solvers. Realizing this integration would greatly enhance the scaling of laser-species interactions beyond the realm of ultra-cold atomic physics. This goal was realized in the present study. A representative numerical investigation, of laser-based neutral atomic and molecular flow manipulations, was conducted using near-resonant and non-resonant laser fields. To simulate the laser interactions over a range of laser and flow conditions, the following tools were employed: a custom collisionless gas particle trajectory code and a specifically modified version of the Direct Simulation Monte Carlo statistical kinetic solver known as SMILE. In addition to the numerical investigations, a validating experiment was conducted. The experimental results showed good agreement with the numerical simulations when experimental parameters, such as finite laser line width, were taken into account. Several areas of interest were addressed: laser induced neutral flow steering, collimation, direct flow acceleration, and neutral gas heating. Near-resonant continuous wave laser, and non-resonant pulsed laser, interactions with cesium and nitrogen were simulated. These simulations showed trends and some limitations associated with these interactions, used for flow

  11. Integrality and separability of multitouch interaction techniques in 3D manipulation tasks.

    Science.gov (United States)

    Martinet, Anthony; Casiez, Géry; Grisoni, Laurent

    2012-03-01

    Multitouch displays represent a promising technology for the display and manipulation of data. While the manipulation of 2D data has been widely explored, 3D manipulation with multitouch displays remains largely unexplored. Based on an analysis of the integration and separation of degrees of freedom, we propose a taxonomy for 3D manipulation techniques with multitouch displays. Using that taxonomy, we introduce Depth-Separated Screen-Space (DS3), a new 3D manipulation technique based on the separation of translation and rotation. In a controlled experiment, we compared DS3 with Sticky Tools and Screen-Space. Results show that separating the control of translation and rotation significantly affects performance for 3D manipulation, with DS3 performing faster than the two other techniques.

  12. Belowground ecosystems [chapter 9

    Science.gov (United States)

    Carole Coe Klopatek

    1995-01-01

    The USDA Forest Service defined ecosystem management as "an ecological approach to achieve multiple-use management of national forests and grasslands by blending the needs of people and environmental values in such a way that national forests and grasslands represent diverse, healthy, productive, and sustainable ecosystems" (June 4, 1992, letter from Chief FS...

  13. Payments for Ecosystem Services

    DEFF Research Database (Denmark)

    Chan, Kai M.A; Anderson, Emily K.; Chapman, Mollie

    2017-01-01

    Payments for ecosystem services (PES) programs are one prominent strategy to address economic externalities of resource extraction and commodity production, improving both social and ecological outcomes. But do PES and related incentive programs achieve that lofty goal? Along with considerable en...... sustainable relationships with nature, conserving and restoring ecosystems and their benefits for people now and in the future....

  14. Ecosystem Management and Sustainability

    Science.gov (United States)

    J.D. Peine; B.L. Jacobs; K.E. Franzreb; M.R. Stevens

    2011-01-01

    Ecosystem management (EM) promotes an integrated approach to environmental issues; its central goal is the protection of entire ecosystems. By focusing on an interdisciplinary solution to environmental challenges, EM can help to synthesize societal, economic scientific, and governmental goals. Furthermore, as EM becomes part of the foundation of environmental...

  15. Radionuclides in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Bocock, K.L.

    1981-01-01

    This report summarizes information on the distribution and movement of radionuclides in semi-natural terrestrial ecosystems in north-west England with particular emphasis on inputs to, and outputs from ecosystems; on plant and soil aspects; and on radionuclides in fallout and in discharges by the nuclear industry. (author)

  16. Effects of Climate and Ecosystem Disturbances on Biogeochemical Cycling in a Semi-Natural Terrestrial Ecosystem

    International Nuclear Information System (INIS)

    Beier, Claus; Schmidt, Inger Kappel; Kristensen, Hanne Lakkenborg

    2004-01-01

    The effects of increased temperature and potential ecosystem disturbances on biogeochemical cycling were investigated by manipulation of temperature in a mixed Calluna/grass heathland in Denmark. A reflective curtain covered the vegetation during the night to reduce the heat loss of IR radiation from the ecosystem to the atmosphere. This 'night time warming' was done for 3 years and warmed the air and soil by 1.1 deg. C. Warming was combined with ecosystem disturbances, including infestation by Calluna heather beetles (Lochmaea suturalis Thompson) causing complete defoliation of Calluna leaves during the summer 2000, and subsequent harvesting of all aboveground biomass during the autumn. Small increases in mineralisation rates were induced by warming and resulted in increased leaching of nitrogen from the organic soil layer. The increased nitrogen leaching from the organic soil layer was re-immobilised in the mineral soil layer as warming stimulated plant growth and thereby increased nitrogen immobilisation. Contradictory to the generally moderate effects of warming, the heather beetle infestation had very strong effects on mineralisation rates and the plant community. The grasses completely out-competed the Calluna plants which had not re-established two years after the infestation, probably due to combined effects of increased nutrient availability and the defoliation of Calluna. On the short term, ecosystem disturbances may have very strong effects on internal ecosystem processes and plant community structure compared to the more long-term effects of climate change

  17. Coastal ecosystems, productivity and ecosystem protection: Coastal ecosystem management

    International Nuclear Information System (INIS)

    Ngoile, M.A.K.; Horrill, C.J.

    1993-01-01

    The coastal zone is a complex ecosystem under the influence of physical, chemical and biological processes. Under natural conditions these processes interact and maintain an equilibrium in the coastal ecosystem. Man makes a variety of important uses of coastal resources, ranging from harvesting of living resources, extraction of nonliving resources, and recreation, to the disposal of wastes. Man's extensive use of the oceans introduces factors which bring about an imbalance in the natural processes, and may result in harmful and hazardous effects to life hindering further use. Man's pressure on the resources of the coastal zone is already manifest and will increase manifold. This calls for an immediate solution to the protection and sustainable use of coastal resources. The current sectorized approach to the management of human activities will not solve the problem because the different resources of the coastal zone interact in such a manner that disturbances in one cause imbalance in the others. This is further complicated by the sectorized approach to research and limited communication between policy makers, managers, and scientists. This paper discusses strategies for managing coastal-resources use through an integrated approach. The coastal zone is presented as a unified ecosystem in equilibrium and shows that man's extensive use of the coastal resources destabilizes this equilibrium. Examples from the East Africa Region are presented. 15 refs, 2 figs, 3 tabs

  18. Biodiversity enhances ecosystem multifunctionality across trophic levels and habitats

    Science.gov (United States)

    Lefcheck, Jonathan S.; Byrnes, Jarrett E. K.; Isbell, Forest; Gamfeldt, Lars; Griffin, John N.; Eisenhauer, Nico; Hensel, Marc J. S.; Hector, Andy; Cardinale, Bradley J.; Duffy, J. Emmett

    2015-01-01

    The importance of biodiversity for the integrated functioning of ecosystems remains unclear because most evidence comes from analyses of biodiversity's effect on individual functions. Here we show that the effects of biodiversity on ecosystem function become more important as more functions are considered. We present the first systematic investigation of biodiversity's effect on ecosystem multifunctionality across multiple taxa, trophic levels and habitats using a comprehensive database of 94 manipulations of species richness. We show that species-rich communities maintained multiple functions at higher levels than depauperate ones. These effects were stronger for herbivore biodiversity than for plant biodiversity, and were remarkably consistent across aquatic and terrestrial habitats. Despite observed tradeoffs, the overall effect of biodiversity on multifunctionality grew stronger as more functions were considered. These results indicate that prior research has underestimated the importance of biodiversity for ecosystem functioning by focusing on individual functions and taxonomic groups. PMID:25907115

  19. Mapping cultural ecosystem services:

    DEFF Research Database (Denmark)

    Paracchini, Maria Luisa; Zulian, Grazia; Kopperoinen, Leena

    2014-01-01

    Research on ecosystem services mapping and valuing has increased significantly in recent years. However, compared to provisioning and regulating services, cultural ecosystem services have not yet been fully integrated into operational frameworks. One reason for this is that transdisciplinarity...... surveys are a main source of information. Among cultural ecosystem services, assessment of outdoor recreation can be based on a large pool of literature developed mostly in social and medical science, and landscape and ecology studies. This paper presents a methodology to include recreation...... in the conceptual framework for EU wide ecosystem assessments (Maes et al., 2013), which couples existing approaches for recreation management at country level with behavioural data derived from surveys, and population distribution data. The proposed framework is based on three components: the ecosystem function...

  20. Wave Manipulation by Topology Optimization

    DEFF Research Database (Denmark)

    Andkjær, Jacob Anders

    topology optimization can be used to design structures for manipulation of the electromagnetic and acoustic waves. The wave problems considered here fall within three classes. The first class concerns the design of cloaks, which when wrapped around an object will render the object undetectable...... for the cloak is to delay the waves in regions of higher permittivity than the background and subsequently phase match them to the waves outside. Directional acoustic cloaks can also be designed using the topology optimization method. Aluminum cylinders constitutes the design and their placement and size...... concerns the design of planar Fresnel zone plate lenses for focusing electromagnetic waves. The topology optimized zone plates improve the focusing performance compared to results known from the literature....

  1. Ion manipulation method and device

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Gordon A.; Baker, Erin M.; Smith, Richard D.; Ibrahim, Yehia M.

    2017-11-07

    An ion manipulation method and device is disclosed. The device includes a pair of substantially parallel surfaces. An array of inner electrodes is contained within, and extends substantially along the length of, each parallel surface. The device includes a first outer array of electrodes and a second outer array of electrodes. Each outer array of electrodes is positioned on either side of the inner electrodes, and is contained within and extends substantially along the length of each parallel surface. A DC voltage is applied to the first and second outer array of electrodes. A RF voltage, with a superimposed electric field, is applied to the inner electrodes by applying the DC voltages to each electrode. Ions either move between the parallel surfaces within an ion confinement area or along paths in the direction of the electric field, or can be trapped in the ion confinement area.

  2. Multidiscipline simulation of elastic manipulators

    Directory of Open Access Journals (Sweden)

    T. Rølvåg

    1992-10-01

    Full Text Available This paper contributes to multidiscipline simulation of elastic robot manipulators in FEDEM. All developments presented in this paper are based on the formulations in FEDEM, a simulation system developed by the authors which combines finite element, mechanism and control analysis. In order to establish this general simulation system as an efficient multidiscipline robot design tool a robot control system including a high level robot programming language, interpolation algorithms, path generation algorithms, forward and inverse kinematics, control systems, gear and transmission models are implemented. These new features provide a high level of integration between traditionally separate design disciplines from the very beginning of the design and optimization process. Several simulations have shown that high fidelity mathematical models can be derived and used as a basis for dynamic analysis and controller design in FEDEM.

  3. Pushing precipitation to the extremes in distributed experiments: Recommendations for simulating wet and dry years

    Science.gov (United States)

    Knapp, Alan K.; Avolio, Meghan L.; Beier, Claus; Carroll, Charles J.W.; Collins, Scott L.; Dukes, Jeffrey S.; Fraser, Lauchlan H.; Griffin-Nolan, Robert J.; Hoover, David L.; Jentsch, Anke; Loik, Michael E.; Phillips, Richard P.; Post, Alison K.; Sala, Osvaldo E.; Slette, Ingrid J.; Yahdjian, Laura; Smith, Melinda D.

    2017-01-01

    Intensification of the global hydrological cycle, ranging from larger individual precipitation events to more extreme multiyear droughts, has the potential to cause widespread alterations in ecosystem structure and function. With evidence that the incidence of extreme precipitation years (defined statistically from historical precipitation records) is increasing, there is a clear need to identify ecosystems that are most vulnerable to these changes and understand why some ecosystems are more sensitive to extremes than others. To date, opportunistic studies of naturally occurring extreme precipitation years, combined with results from a relatively small number of experiments, have provided limited mechanistic understanding of differences in ecosystem sensitivity, suggesting that new approaches are needed. Coordinated distributed experiments (CDEs) arrayed across multiple ecosystem types and focused on water can enhance our understanding of differential ecosystem sensitivity to precipitation extremes, but there are many design challenges to overcome (e.g., cost, comparability, standardization). Here, we evaluate contemporary experimental approaches for manipulating precipitation under field conditions to inform the design of ‘Drought-Net’, a relatively low-cost CDE that simulates extreme precipitation years. A common method for imposing both dry and wet years is to alter each ambient precipitation event. We endorse this approach for imposing extreme precipitation years because it simultaneously alters other precipitation characteristics (i.e., event size) consistent with natural precipitation patterns. However, we do not advocate applying identical treatment levels at all sites – a common approach to standardization in CDEs. This is because precipitation variability varies >fivefold globally resulting in a wide range of ecosystem-specific thresholds for defining extreme precipitation years. For CDEs focused on precipitation extremes, treatments should be based

  4. Changes in canopy structure and ant assemblages affect soil ecosystem variables as a foundation species declines

    DEFF Research Database (Denmark)

    Kendrick, Joseph A.; Ribbons, Relena Rose; Classen, Aimee Taylor

    2015-01-01

    in ant species composition would interact to alter soil ecosystem variables. In the Harvard Forest Hemlock Removal Experiment (HF-HeRE), established in 2003, T. canadensis in large plots were killed in place or logged and removed to mimic adelgid infestation or salvage harvesting, respectively. In 2006...... (richness and abundance) of ants increases rapidly as T. canadensis is lost from the stands. Because ants live and forage at the litter-soil interface, we hypothesized that environmental changes caused by hemlock loss (e.g., increased light and warmth at the forest floor, increased soil pH) and shifts......, we built ant exclosure subplots within all of the canopy manipulation plots to examine direct and interactive effects of canopy change and ant assemblage composition on soil and litter variables. Throughout HF-HeRE, T. canadensis was colonized by the adelgid in 2009, and the infested trees are now...

  5. Critical element study on autonomous position control of articulated-arm type manipulator

    International Nuclear Information System (INIS)

    Oka, Kiyoshi; Kakudate, Satoshi; Nakahira, Masataka

    1994-10-01

    An articulated-arm type manipulator can be operated effectively in a restricted space due to its flexibility and it can be attractive for a wide range of in-vessel maintenance such as viewing, inspection and limiter handling in fusion experimental reactors. In case of the in-vessel maintenance using a flexible manipulator, it is quite essential to develop an autonomous control method for compensating a deflection of manipulator so as to minimize the maintenance time with high precision. For this purpose, a new position control method using a combination of neural network predictor with a rigid inverse kinematics is being developed. The key features of this method are to simplify a kinematics modeling of flexible manipulator, to enable quick position compensation in stead of ordinary large matrix compensation, and to be applicable to a wide variety of manipulator characteristics. A sub-scaled model of flexible manipulator with 4 joints has been fabricated for a benchmark experiments of the autonomous position control. Comparing analytical simulation with experiments using the flexible manipulator, it has been demonstrated that the new position control method gives significant improvement in control performance with high precision in order of a figure. In addition, further optimization can be possible by adding other non-linear predictors such as radial basis function and fuzzy modeling. This paper describes the details of a sub-scaled flexible manipulator and a neural network position control system as well as results of analytical simulation and benchmark experiments. (author)

  6. Encoding specificity manipulations do affect retrieval from memory.

    Science.gov (United States)

    Zeelenberg, René

    2005-05-01

    In a recent article, P.A. Higham (2002) [Strong cues are not necessarily weak: Thomson and Tulving (1970) and the encoding specificity principle revisited. Memory &Cognition, 30, 67-80] proposed a new way to analyze cued recall performance in terms of three separable aspects of memory (retrieval, monitoring, and report bias) by comparing performance under both free-report and forced-report instructions. He used this method to derive estimates of these aspects of memory in an encoding specificity experiment similar to that reported by D.M. Thomson and E. Tulving (1970) [Associative encoding and retrieval: weak and strong cues. Journal of Experimental Psychology, 86, 255-262]. Under forced-report instructions, the encoding specificity manipulation did not affect performance. Higham concluded that the manipulation affected monitoring and report bias, but not retrieval. I argue that this interpretation of the results is problematic because the Thomson and Tulving paradigm is confounded, and show in three experiments using a more appropriate design that encoding specificity manipulations do affect performance in forced-report cued recall. Because in Higham's framework forced-report performance provides a measure of retrieval that is uncontaminated by monitoring and report bias it is concluded that encoding specificity manipulations do affect retrieval from memory.

  7. Spatial interactions among ecosystem services in an urbanizing agricultural watershed.

    Science.gov (United States)

    Qiu, Jiangxiao; Turner, Monica G

    2013-07-16

    Understanding spatial distributions, synergies, and tradeoffs of multiple ecosystem services (benefits people derive from ecosystems) remains challenging. We analyzed the supply of 10 ecosystem services for 2006 across a large urbanizing agricultural watershed in the Upper Midwest of the United States, and asked the following: (i) Where are areas of high and low supply of individual ecosystem services, and are these areas spatially concordant across services? (ii) Where on the landscape are the strongest tradeoffs and synergies among ecosystem services located? (iii) For ecosystem service pairs that experience tradeoffs, what distinguishes locations that are "win-win" exceptions from other locations? Spatial patterns of high supply for multiple ecosystem services often were not coincident; locations where six or more services were produced at high levels (upper 20th percentile) occupied only 3.3% of the landscape. Most relationships among ecosystem services were synergies, but tradeoffs occurred between crop production and water quality. Ecosystem services related to water quality and quantity separated into three different groups, indicating that management to sustain freshwater services along with other ecosystem services will not be simple. Despite overall tradeoffs between crop production and water quality, some locations were positive for both, suggesting that tradeoffs are not inevitable everywhere and might be ameliorated in some locations. Overall, we found that different areas of the landscape supplied different suites of ecosystem services, and their lack of spatial concordance suggests the importance of managing over large areas to sustain multiple ecosystem services.

  8. Ecosystem approach in education

    Science.gov (United States)

    Nabiullin, Iskander

    2017-04-01

    Environmental education is a base for sustainable development. Therefore, in our school we pay great attention to environmental education. Environmental education in our school is based on ecosystem approach. What is an ecosystem approach? Ecosystem is a fundamental concept of ecology. Living organisms and their non-living environments interact with each other as a system, and the biosphere planet functions as a global ecosystem. Therefore, it is necessary for children to understand relationships in ecosystems, and we have to develop systems thinking in our students. Ecosystem approach and systems thinking should help us to solve global environmental problems. How do we implement the ecosystem approach? Students must understand that our biosphere functions as a single ecosystem and even small changes can lead to environmental disasters. Even the disappearance of one plant or animal species can lead to irreversible consequences. So in the classroom we learn the importance of each living organism for the nature. We pay special attention to endangered species, which are listed in the Red Data List. Kids are doing projects about these organisms, make videos, print brochures and newspapers. Fieldwork also plays an important role for ecosystem approach. Every summer, we go out for expeditions to study species of plants and animals listed in the Red Data List of Tatarstan. In class, students often write essays on behalf of any endangered species of plants or animals, this also helps them to understand the importance of each living organism in nature. Each spring we organise a festival of environmental projects among students. Groups of 4-5 students work on a solution of environmental problems, such as water, air or soil pollution, waste recycling, the loss of biodiversity, etc. Participants shoot a clip about their project, print brochures. Furthermore, some of the students participate in national and international scientific Olympiads with their projects. In addition to

  9. A links manipulator simulation program interim report

    International Nuclear Information System (INIS)

    Noble, R.A.

    1987-04-01

    A computer program to simulate the performance of the Heysham II rail-following manipulator has been developed. The program is being used to develop and test the rail-following control algorithms which will be used to control movements of the manipulator when it is operating below the gas baffle dome. The simulation includes the dynamic responses of the manipulator joint drives, excluding friction, backlash and compliance. It also includes full details of the manipulator's geometry. A method is given whereby the actual manipulator dynamics can be written into the program once these have been established by measurement. The program is written in FORTRAN and runs on a Perkin-Elmer 3220 mini-computer. The simulation program responds to velocity demands on the individual joints. These will normally come from the control program, in which they will be manually controlled by a joystick. A sigma 5664 colour graphics generator is programmed to display the current position of the manipulator. (UK)

  10. Probabilistic approach to manipulator kinematics and dynamics

    International Nuclear Information System (INIS)

    Rao, S.S.; Bhatti, P.K.

    2001-01-01

    A high performance, high speed robotic arm must be able to manipulate objects with a high degree of accuracy and repeatability. As with any other physical system, there are a number of factors causing uncertainties in the behavior of a robotic manipulator. These factors include manufacturing and assembling tolerances, and errors in the joint actuators and controllers. In order to study the effect of these uncertainties on the robotic end-effector and to obtain a better insight into the manipulator behavior, the manipulator kinematics and dynamics are modeled using a probabilistic approach. Based on the probabilistic model, kinematic and dynamic performance criteria are defined to provide measures of the behavior of the robotic end-effector. Techniques are presented to compute the kinematic and dynamic reliabilities of the manipulator. The effects of tolerances associated with the various manipulator parameters on the reliabilities are studied. Numerical examples are presented to illustrate the procedures

  11. Collision Detection for Underwater ROV Manipulator Systems

    Directory of Open Access Journals (Sweden)

    Satja Sivčev

    2018-04-01

    Full Text Available Work-class ROVs equipped with robotic manipulators are extensively used for subsea intervention operations. Manipulators are teleoperated by human pilots relying on visual feedback from the worksite. Operating in a remote environment, with limited pilot perception and poor visibility, manipulator collisions which may cause significant damage are likely to happen. This paper presents a real-time collision detection algorithm for marine robotic manipulation. The proposed collision detection mechanism is developed, integrated into a commercial ROV manipulator control system, and successfully evaluated in simulations and experimental setup using a real industry standard underwater manipulator. The presented collision sensing solution has a potential to be a useful pilot assisting tool that can reduce the task load, operational time, and costs of subsea inspection, repair, and maintenance operations.

  12. Non-linear density-dependent effects of an intertidal ecosystem engineer.

    Science.gov (United States)

    Harley, Christopher D G; O'Riley, Jaclyn L

    2011-06-01

    Ecosystem engineering is an important process in a variety of ecosystems. However, the relationship between engineer density and engineering impact remains poorly understood. We used experiments and a mathematical model to examine the role of engineer density in a rocky intertidal community in northern California. In this system, the whelk Nucella ostrina preys on barnacles (Balanus glandula and Chthamalus dalli), leaving empty barnacle tests as a resource (favorable microhabitat) for other species. Field experiments demonstrated that N. ostrina predation increased the availability of empty tests of both barnacle species, reduced the density of the competitively dominant B. glandula, and indirectly increased the density of the competitively inferior C. dalli. Empty barnacle tests altered microhabitat humidity, but not temperature, and presumably provided a refuge from wave action. The herbivorous snail Littorina plena was positively associated with empty test availability in both observational comparisons and experimental manipulations of empty test availability, and L. plena density was elevated in areas with foraging N. ostrina. To explore the effects of variation in N. ostrina predation, we constructed a demographic matrix model for barnacles in which we varied predation intensity. The model predicted that number of available empty tests increases with predation intensity to a point, but declines when predation pressure was strong enough to severely reduce adult barnacle densities. The modeled number of available empty tests therefore peaked at an intermediate level of N. ostrina predation. Non-linear relationships between engineer density and engineer impact may be a generally important attribute of systems in which engineers influence the population dynamics of the species that they manipulate.

  13. Master-slave-manipulator 'EMSM I'

    International Nuclear Information System (INIS)

    Koehler, G.W.; Salaske, M.

    1976-01-01

    A master-slave manipulator with electric force transmission and reflection was developed for the first time in the German Federal Republic. The apparatus belongs to the class of 200 N carrying capacity. It is intended mainly for nuclear purposes and especially for use in large hot cells and also for medium and heavy manipulator vehicles. The most innovations compared with previously known foreign electric master-slave manipulators are two additional possibilities of movement and the electric dead weight compensation. (orig.) [de

  14. Master-slave-manipulator EMSM I

    International Nuclear Information System (INIS)

    Koehler, G.W.; Salaske, M.

    1976-01-01

    A master-slave manipulator with electric force transmission and reflection was developed for the first time in the German Federal Republic. The aparatus belongs to the class of 200 N carrying capacity. It is intended mainly for nuclear purposes and especially for use in large hot cells and also for medium and heavy manipulator vehicles. The most obvious innovations compared with previously known foreign electric master-slave manipulators are two additional possibilities of movement and the electric dead weightcompensation. (orig.) [de

  15. Positional control of space robot manipulator

    Science.gov (United States)

    Kurochkin, Vladislav; Shymanchuk, Dzmitry

    2018-05-01

    In this article the mathematical model of a planar space robot manipulator is under study. The space robot manipulator represents a solid body with attached manipulators. The system of equations of motion is determined using the Lagrange's equations. The control problem concerning moving the robot to a given point and return it to a given trajectory in the phase space is solved. Changes of generalized coordinates and necessary control actions are plotted for a specific model.

  16. Managerial Incentives and Stock Price Manipulation

    OpenAIRE

    Peng, Lin; Röell, Ailsa A

    2009-01-01

    This paper presents a rational expectations model of optimal executive compensation in a setting where managers are in a position to manipulate short-term stock prices, and managers' propensity to manipulate is uncertain. Stock-based incentives elicit not only productive effort, but also costly information manipulation. We analyze the tradeoffs involved in conditioning pay on long- versus short-term performance and characterize a second-best optimal compensation scheme. The paper shows manipu...

  17. Seismic qualification of existing safety class manipulators

    International Nuclear Information System (INIS)

    Wu, Ting-shu; Moran, T.J.

    1992-01-01

    There are two bridge type electromechanical manipulators within a nuclear fuel handling facility which were constructed over twenty-five years ago. At that time, there were only minimal seismic considerations. These manipulators together with the facility are being reactivated. Detailed analyses have shown that the manipulators will satisfy the requirements of ANSI/AISC N690-1984 when they are subjected to loadings including the site specific design basis earthquake. 4 refs

  18. An invasive foundation species enhances multifunctionality in a coastal ecosystem.

    Science.gov (United States)

    Ramus, Aaron P; Silliman, Brian R; Thomsen, Mads S; Long, Zachary T

    2017-08-08

    While invasive species often threaten biodiversity and human well-being, their potential to enhance functioning by offsetting the loss of native habitat has rarely been considered. We manipulated the abundance of the nonnative, habitat-forming seaweed Gracilaria vermiculophylla in large plots (25 m 2 ) on southeastern US intertidal landscapes to assess impacts on multiple ecosystem functions underlying coastal ecosystem services. We document that in the absence of native habitat formers, this invasion has an overall positive, density-dependent impact across a diverse set of ecosystem processes (e.g., abundance and richness of nursery taxa, flow attenuation). Manipulation of invader abundance revealed both thresholds and saturations in the provisioning of ecosystem functions. Taken together, these findings call into question the focus of traditional invasion research and management that assumes negative effects of nonnatives, and emphasize the need to consider context-dependence and integrative measurements when assessing the impact of an invader, including density dependence, multifunctionality, and the status of native habitat formers. This work supports discussion of the idea that where native foundation species have been lost, invasive habitat formers may be considered as sources of valuable ecosystem functions.

  19. BioWord: A sequence manipulation suite for Microsoft Word

    Directory of Open Access Journals (Sweden)

    Anzaldi Laura J

    2012-06-01

    Full Text Available Abstract Background The ability to manipulate, edit and process DNA and protein sequences has rapidly become a necessary skill for practicing biologists across a wide swath of disciplines. In spite of this, most everyday sequence manipulation tools are distributed across several programs and web servers, sometimes requiring installation and typically involving frequent switching between applications. To address this problem, here we have developed BioWord, a macro-enabled self-installing template for Microsoft Word documents that integrates an extensive suite of DNA and protein sequence manipulation tools. Results BioWord is distributed as a single macro-enabled template that self-installs with a single click. After installation, BioWord will open as a tab in the Office ribbon. Biologists can then easily manipulate DNA and protein sequences using a familiar interface and minimize the need to switch between applications. Beyond simple sequence manipulation, BioWord integrates functionality ranging from dyad search and consensus logos to motif discovery and pair-wise alignment. Written in Visual Basic for Applications (VBA as an open source, object-oriented project, BioWord allows users with varying programming experience to expand and customize the program to better meet their own needs. Conclusions BioWord integrates a powerful set of tools for biological sequence manipulation within a handy, user-friendly tab in a widely used word processing software package. The use of a simple scripting language and an object-oriented scheme facilitates customization by users and provides a very accessible educational platform for introducing students to basic bioinformatics algorithms.

  20. BioWord: A sequence manipulation suite for Microsoft Word

    Science.gov (United States)

    2012-01-01

    Background The ability to manipulate, edit and process DNA and protein sequences has rapidly become a necessary skill for practicing biologists across a wide swath of disciplines. In spite of this, most everyday sequence manipulation tools are distributed across several programs and web servers, sometimes requiring installation and typically involving frequent switching between applications. To address this problem, here we have developed BioWord, a macro-enabled self-installing template for Microsoft Word documents that integrates an extensive suite of DNA and protein sequence manipulation tools. Results BioWord is distributed as a single macro-enabled template that self-installs with a single click. After installation, BioWord will open as a tab in the Office ribbon. Biologists can then easily manipulate DNA and protein sequences using a familiar interface and minimize the need to switch between applications. Beyond simple sequence manipulation, BioWord integrates functionality ranging from dyad search and consensus logos to motif discovery and pair-wise alignment. Written in Visual Basic for Applications (VBA) as an open source, object-oriented project, BioWord allows users with varying programming experience to expand and customize the program to better meet their own needs. Conclusions BioWord integrates a powerful set of tools for biological sequence manipulation within a handy, user-friendly tab in a widely used word processing software package. The use of a simple scripting language and an object-oriented scheme facilitates customization by users and provides a very accessible educational platform for introducing students to basic bioinformatics algorithms. PMID:22676326

  1. BioWord: a sequence manipulation suite for Microsoft Word.

    Science.gov (United States)

    Anzaldi, Laura J; Muñoz-Fernández, Daniel; Erill, Ivan

    2012-06-07

    The ability to manipulate, edit and process DNA and protein sequences has rapidly become a necessary skill for practicing biologists across a wide swath of disciplines. In spite of this, most everyday sequence manipulation tools are distributed across several programs and web servers, sometimes requiring installation and typically involving frequent switching between applications. To address this problem, here we have developed BioWord, a macro-enabled self-installing template for Microsoft Word documents that integrates an extensive suite of DNA and protein sequence manipulation tools. BioWord is distributed as a single macro-enabled template that self-installs with a single click. After installation, BioWord will open as a tab in the Office ribbon. Biologists can then easily manipulate DNA and protein sequences using a familiar interface and minimize the need to switch between applications. Beyond simple sequence manipulation, BioWord integrates functionality ranging from dyad search and consensus logos to motif discovery and pair-wise alignment. Written in Visual Basic for Applications (VBA) as an open source, object-oriented project, BioWord allows users with varying programming experience to expand and customize the program to better meet their own needs. BioWord integrates a powerful set of tools for biological sequence manipulation within a handy, user-friendly tab in a widely used word processing software package. The use of a simple scripting language and an object-oriented scheme facilitates customization by users and provides a very accessible educational platform for introducing students to basic bioinformatics algorithms.

  2. 3D Laser Scanner for Underwater Manipulation

    Directory of Open Access Journals (Sweden)

    Albert Palomer

    2018-04-01

    Full Text Available Nowadays, research in autonomous underwater manipulation has demonstrated simple applications like picking an object from the sea floor, turning a valve or plugging and unplugging a connector. These are fairly simple tasks compared with those already demonstrated by the mobile robotics community, which include, among others, safe arm motion within areas populated with a priori unknown obstacles or the recognition and location of objects based on their 3D model to grasp them. Kinect-like 3D sensors have contributed significantly to the advance of mobile manipulation providing 3D sensing capabilities in real-time at low cost. Unfortunately, the underwater robotics community is lacking a 3D sensor with similar capabilities to provide rich 3D information of the work space. In this paper, we present a new underwater 3D laser scanner and demonstrate its capabilities for underwater manipulation. In order to use this sensor in conjunction with manipulators, a calibration method to find the relative position between the manipulator and the 3D laser scanner is presented. Then, two different advanced underwater manipulation tasks beyond the state of the art are demonstrated using two different manipulation systems. First, an eight Degrees of Freedom (DoF fixed-base manipulator system is used to demonstrate arm motion within a work space populated with a priori unknown fixed obstacles. Next, an eight DoF free floating Underwater Vehicle-Manipulator System (UVMS is used to autonomously grasp an object from the bottom of a water tank.

  3. Long-reach manipulators for decommissioning

    International Nuclear Information System (INIS)

    Webster, D.A.; Challinor, S.F.

    1993-01-01

    A survey of redundant facilities at Sellafield has identified that in many cases the conventional means of deploying remote handling equipment are not appropriate and that novel means must be employed. However, decommissioning is not a value adding activity and so expensive one off designs must be avoided. The paper will describe BNFL's approach to the synthesis from proprietary parts of a manipulator which can lift 3 te at a horizontal reach of over 5 metres and yet can still perform the dextrous manipulation necessary to remove small items. It will also cover the development of the manipulator control systems and the adaption of commercial handtools to be manipulator friendly. (author)

  4. Nano-manipulation of single DNA molecules

    International Nuclear Information System (INIS)

    Hu Jun; Shanghai Jiaotong Univ., Shanghai; Lv Junhong; Wang Guohua; Wang Ying; Li Minqian; Zhang Yi; Li Bin; Li Haikuo; An Hongjie

    2004-01-01

    Nano-manipulation of single atoms and molecules is a critical technique in nanoscience and nanotechnology. This review paper will focus on the recent development of the manipulation of single DNA molecules based on atomic force microscopy (AFM). Precise manipulation has been realized including varied manipulating modes such as 'cutting', 'pushing', 'folding', 'kneading', 'picking up', 'dipping', etc. The cutting accuracy is dominated by the size of the AFM tip, which is usually 10 nm or less. Single DNA fragments can be cut and picked up and then amplified by single molecule PCR. Thus positioning isolation and sequencing can be performed. (authors)

  5. Bioprinting Living Biofilms through Optogenetic Manipulation.

    Science.gov (United States)

    Huang, Yajia; Xia, Aiguo; Yang, Guang; Jin, Fan

    2018-04-18

    In this paper, we present a new strategy for microprinting dense bacterial communities with a prescribed organization on a substrate. Unlike conventional bioprinting techniques that require bioinks, through optogenetic manipulation, we directly manipulated the behaviors of Pseudomonas aeruginosa to allow these living bacteria to autonomically form patterned biofilms following prescribed illumination. The results showed that through optogenetic manipulation, patterned bacterial communities with high spatial resolution (approximately 10 μm) could be constructed in 6 h. Thus, optogenetic manipulation greatly increases the range of available bioprinting techniques.

  6. 3D Laser Scanner for Underwater Manipulation.

    Science.gov (United States)

    Palomer, Albert; Ridao, Pere; Youakim, Dina; Ribas, David; Forest, Josep; Petillot, Yvan

    2018-04-04

    Nowadays, research in autonomous underwater manipulation has demonstrated simple applications like picking an object from the sea floor, turning a valve or plugging and unplugging a connector. These are fairly simple tasks compared with those already demonstrated by the mobile robotics community, which include, among others, safe arm motion within areas populated with a priori unknown obstacles or the recognition and location of objects based on their 3D model to grasp them. Kinect-like 3D sensors have contributed significantly to the advance of mobile manipulation providing 3D sensing capabilities in real-time at low cost. Unfortunately, the underwater robotics community is lacking a 3D sensor with similar capabilities to provide rich 3D information of the work space. In this paper, we present a new underwater 3D laser scanner and demonstrate its capabilities for underwater manipulation. In order to use this sensor in conjunction with manipulators, a calibration method to find the relative position between the manipulator and the 3D laser scanner is presented. Then, two different advanced underwater manipulation tasks beyond the state of the art are demonstrated using two different manipulation systems. First, an eight Degrees of Freedom (DoF) fixed-base manipulator system is used to demonstrate arm motion within a work space populated with a priori unknown fixed obstacles. Next, an eight DoF free floating Underwater Vehicle-Manipulator System (UVMS) is used to autonomously grasp an object from the bottom of a water tank.

  7. Adverse events among seniors receiving spinal manipulation and exercise in a randomized clinical trial

    DEFF Research Database (Denmark)

    Maiers, Michele; Evans, Roni; Hartvigsen, Jan

    2015-01-01

    Spinal manipulative therapy (SMT) and exercise have demonstrated effectiveness for neck pain (NP). Adverse events (AE) reporting in trials, particularly among elderly participants, is inconsistent and challenges informed clinical decision making. This paper provides a detailed report of AE experi...

  8. NGSUtils: a software suite for analyzing and manipulating next-generation sequencing datasets

    OpenAIRE

    Breese, Marcus R.; Liu, Yunlong

    2013-01-01

    Summary: NGSUtils is a suite of software tools for manipulating data common to next-generation sequencing experiments, such as FASTQ, BED and BAM format files. These tools provide a stable and modular platform for data management and analysis.

  9. Inertial particle manipulation in microscale oscillatory flows

    Science.gov (United States)

    Agarwal, Siddhansh; Rallabandi, Bhargav; Raju, David; Hilgenfeldt, Sascha

    2017-11-01

    Recent work has shown that inertial effects in oscillating flows can be exploited for simultaneous transport and differential displacement of microparticles, enabling size sorting of such particles on extraordinarily short time scales. Generalizing previous theory efforts, we here derive a two-dimensional time-averaged version of the Maxey-Riley equation that includes the effect of an oscillating interface to model particle dynamics in such flows. Separating the steady transport time scale from the oscillatory time scale results in a simple and computationally efficient reduced model that preserves all slow-time features of the full unsteady Maxey-Riley simulations, including inertial particle displacement. Comparison is made not only to full simulations, but also to experiments using oscillating bubbles as the driving interfaces. In this case, the theory predicts either an attraction to or a repulsion from the bubble interface due to inertial effects, so that versatile particle manipulation is possible using differences in particle size, particle/fluid density contrast and streaming strength. We also demonstrate that these predictions are in agreement with experiments.

  10. Beliefs in the population about cracking sounds produced during spinal manipulation.

    Science.gov (United States)

    Demoulin, Christophe; Baeri, Damien; Toussaint, Geoffrey; Cagnie, Barbara; Beernaert, Axel; Kaux, Jean-François; Vanderthommen, Marc

    2018-03-01

    To examine beliefs about cracking sounds heard during high-velocity low-amplitude (HVLA) thrust spinal manipulation in individuals with and without personal experience of this technique. We included 100 individuals. Among them, 60 had no history of spinal manipulation, including 40 who were asymptomatic with or without a past history of spinal pain and 20 who had nonspecific spinal pain. The remaining 40 patients had a history of spinal manipulation; among them, 20 were asymptomatic and 20 had spinal pain. Participants attended a one-on-one interview during which they completed a questionnaire about their history of spinal manipulation and their beliefs regarding sounds heard during spinal manipulation. Mean age was 43.5±15.4years. The sounds were ascribed to vertebral repositioning by 49% of participants and to friction between two vertebras by 23% of participants; only 9% of participants correctly ascribed the sound to the formation of a gas bubble in the joint. The sound was mistakenly considered to indicate successful spinal manipulation by 40% of participants. No differences in beliefs were found between the groups with and without a history of spinal manipulation. Certain beliefs have documented adverse effects. This study showed a high prevalence of unfounded beliefs regarding spinal manipulation. These beliefs deserve greater attention from healthcare providers, particularly those who practice spinal manipulation. Copyright © 2017 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

  11. Urgent need for warming experiments in tropical forests

    Science.gov (United States)

    Calaveri, Molly A.; Reed, Sasha C.; Smith, W. Kolby; Wood, Tana E.

    2015-01-01

    Although tropical forests account for only a fraction of the planet's terrestrial surface, they exchange more carbon dioxide with the atmosphere than any other biome on Earth, and thus play a disproportionate role in the global climate. In the next 20 years, the tropics will experience unprecedented warming, yet there is exceedingly high uncertainty about their potential responses to this imminent climatic change. Here, we prioritize research approaches given both funding and logistical constraints in order to resolve major uncertainties about how tropical forests function and also to improve predictive capacity of earth system models. We investigate overall model uncertainty of tropical latitudes and explore the scientific benefits and inevitable trade-offs inherent in large-scale manipulative field experiments. With a Coupled Model Intercomparison Project Phase 5 analysis, we found that model variability in projected net ecosystem production was nearly 3 times greater in the tropics than for any other latitude. Through a review of the most current literature, we concluded that manipulative warming experiments are vital to accurately predict future tropical forest carbon balance, and we further recommend the establishment of a network of comparable studies spanning gradients of precipitation, edaphic qualities, plant types, and/or land use change. We provide arguments for long-term, single-factor warming experiments that incorporate warming of the most biogeochemically active ecosystem components (i.e. leaves, roots, soil microbes). Hypothesis testing of underlying mechanisms should be a priority, along with improving model parameterization and constraints. No single tropical forest is representative of all tropical forests; therefore logistical feasibility should be the most important consideration for locating large-scale manipulative experiments. Above all, we advocate for multi-faceted research programs, and we offer arguments for what we consider the most

  12. Plasma manipulation techniques for positron storage in a multicell trap

    International Nuclear Information System (INIS)

    Danielson, J. R.; Weber, T. R.; Surko, C. M.

    2006-01-01

    New plasma manipulation techniques are described that are central to the development of a multicell Penning trap designed to increase positron storage by orders of magnitude (e.g., to particle numbers N≥10 12 ). The experiments are done using test electron plasmas. A technique is described to move plasmas across the confining magnetic field and to deposit them at specific radial and azimuthal positions. Techniques to fill and operate two in-line plasma cells simultaneously, and the use of 1 kV confinement potentials are demonstrated. These experiments establish the capabilities to create, confine, and manipulate plasmas with the parameters required for a multicell trap; namely, particle numbers >10 10 in a single cell with plasma temperature ≤0.2 eV for plasma lengths ∼10 cm and radii ≤0.2 cm. The updated design of a multicell positron trap for 10 12 particles is described

  13. Ecosystem quality in LCIA

    DEFF Research Database (Denmark)

    Woods, John S.; Damiani, Mattia; Fantke, Peter

    2017-01-01

    Purpose: Life cycle impact assessment (LCIA) results are used to assess potential environmental impacts of different products and services. As part of the UNEP-SETAC life cycle initiative flagship project that aims to harmonize indicators of potential environmental impacts, we provide a consensus...... viewpoint and recommendations for future developments in LCIA related to the ecosystem quality area of protection (AoP). Through our recommendations, we aim to encourage LCIA developments that improve the usefulness and global acceptability of LCIA results. Methods: We analyze current ecosystem quality...... metrics and provide recommendations to the LCIA research community for achieving further developments towards comparable and more ecologically relevant metrics addressing ecosystem quality. Results and discussion: We recommend that LCIA development for ecosystem quality should tend towards species...

  14. List identifies threatened ecosystems

    Science.gov (United States)

    Showstack, Randy

    2012-09-01

    The International Union for Conservation of Nature (IUCN) announced on 9 September that it will develop a new Red List of Ecosystems that will identify which ecosystems are vulnerable or endangered. The list, which is modeled on the group's Red List of Threatened Species™, could help to guide conservation activities and influence policy processes such as the Convention on Biological Diversity, according to the group. “We will assess the status of marine, terrestrial, freshwater, and subterranean ecosystems at local, regional, and global levels,” stated Jon Paul Rodriguez, leader of IUCN's Ecosystems Red List Thematic Group. “The assessment can then form the basis for concerted implementation action so that we can manage them sustainably if their risk of collapse is low or restore them if they are threatened and then monitor their recovery.”

  15. Formation of Service Ecosystems

    DEFF Research Database (Denmark)

    Jonas, Julia M.; Sörhammar, David; Satzger, Gerhard

    – i.e. the “birth phase” (Moore, 2009) of a service ecosystem. This paper, therefore, aims to explore how the somewhat “magic” processes of service ecosystem formation that are being taken for granted actually occur. Methodology/Approach: Building on a review of core elements in the definitions...... for Harvard students) or value proposition (share messages, photos, videos, etc. with friends). Processes of configuring actors, resources, and value propositions are influenced by the structural embeddedness of the service ecosystem (e.g., regional infrastructure, existing networks of actors, or resource...... availability) as well as guided by the actors’ own and shared institutions (e.g., rules, norms,and beliefs).We contextualize each starting point with illustrative cases and analyze the service ecosystem configuration process: “Axoon/Trumpf” (initiated by resources), “JOSEPHS – the service manufactory...

  16. Revisiting software ecosystems research

    DEFF Research Database (Denmark)

    Manikas, Konstantinos

    2016-01-01

    ‘Software ecosystems’ is argued to first appear as a concept more than 10 years ago and software ecosystem research started to take off in 2010. We conduct a systematic literature study, based on the most extensive literature review in the field up to date, with two primarily aims: (a) to provide...... an updated overview of the field and (b) to document evolution in the field. In total, we analyze 231 papers from 2007 until 2014 and provide an overview of the research in software ecosystems. Our analysis reveals a field that is rapidly growing both in volume and empirical focus while becoming more mature...... from evolving. We propose means for future research and the community to address them. Finally, our analysis shapes the view of the field having evolved outside the existing definitions of software ecosystems and thus propose the update of the definition of software ecosystems....

  17. Ecosystem Analysis Program

    International Nuclear Information System (INIS)

    Burgess, R.L.

    1978-01-01

    Progress is reported on the following research programs: analysis and modeling of ecosystems; EDFB/IBP data center; biome analysis studies; land/water interaction studies; and computer programs for development of models

  18. Dielectric nanoresonators for light manipulation

    Science.gov (United States)

    Yang, Zhong-Jian; Jiang, Ruibin; Zhuo, Xiaolu; Xie, Ya-Ming; Wang, Jianfang; Lin, Hai-Qing

    2017-07-01

    Nanostructures made of dielectric materials with high or moderate refractive indexes can support strong electric and magnetic resonances in the optical region. They can therefore function as nanoresonators. In addition to plasmonic metal nanostructures that have been widely investigated, dielectric nanoresonators provide a new type of building blocks for realizing powerful and versatile nanoscale light manipulation. In contrast to plasmonic metal nanostructures, nanoresonators made of appropriate dielectric materials are low-cost, earth-abundant and have very small or even negligible light energy losses. As a result, they will find potential applications in a number of photonic devices, especially those that require low energy losses. In this review, we describe the recent progress on the experimental and theoretical studies of dielectric nanoresonators. We start from the basic theory of the electromagnetic responses of dielectric nanoresonators and their fabrication methods. The optical properties of individual dielectric nanoresonators are then elaborated, followed by the coupling behaviors between dielectric nanoresonators, between dielectric nanoresonators and substrates, and between dielectric nanoresonators and plasmonic metal nanostructures. The applications of dielectric nanoresonators are further described. Finally, the challenges and opportunities in this field are discussed.

  19. Stakeholder Values and Ecosystems

    OpenAIRE

    Sveinsdottir, Thordis; Wessels, Bridgette; Smallwood, Rod; Linde, Peter; Kalla, Vasso; Tsoukala, Victoria; Sondervan, Jeroen

    2013-01-01

    This report is the deliverable for Work Package 1 (WP1), Stakeholder Values and Ecosystems, of the EU FP7 funded project RECODE (Grant Agreement No: 321463), which focuses on developing Policy Recommendations for Open Access to Research Data in Europe. WP1 focuses on understanding stakeholder values and ecosystems in Open Access, dissemination and preservation in the area of scientific and scholarly data (thus not government data). The objectives of this WP are as follows: • Identify and map ...

  20. Terrestrial ecosystems and biodiversity

    CSIR Research Space (South Africa)

    Davis-Reddy, Claire

    2017-10-01

    Full Text Available Ecoregions Terrestrial Biomes Protected Areas Climate Risk and Vulnerability: A Handbook for Southern Africa | 75 7.2. Non-climatic drivers of ecosystem change 7.2.1. Land-use change, habitat loss and fragmentation Land-use change and landscape... concentrations of endemic plant and animal species, but these mainly occur in areas that are most threatened by human activity. Diverse terrestrial ecosystems in the region include tropical and sub-tropical forests, deserts, savannas, grasslands, mangroves...

  1. Privacy driven internet ecosystem

    OpenAIRE

    Trinh, Tuan Anh; Gyarmati, Laszlo

    2012-01-01

    The dominant business model of today's Internet is built upon advertisements; users can access Internet services while the providers show ads to them. Although significant efforts have been made to model and analyze the economic aspects of this ecosystem, the heart of the current status quo, namely privacy, has not received the attention of the research community yet. Accordingly, we propose an economic model of the privacy driven Internet ecosystem where privacy is handled as an asset that c...

  2. A systematic review of the use of dosage form manipulation to obtain required doses to inform use of manipulation in paediatric practice.

    Science.gov (United States)

    Richey, Roberta H; Hughes, Clare; Craig, Jean V; Shah, Utpal U; Ford, James L; Barker, Catrin E; Peak, Matthew; Nunn, Anthony J; Turner, Mark A

    2017-02-25

    This study sought to determine whether there is an evidence base for drug manipulation to obtain the required dose, a common feature of paediatric clinical practice. A systematic review of the data sources, PubMed, EMBASE, CINAHL, IPA and the Cochrane database of systematic reviews, was used. Studies that considered the dose accuracy of manipulated medicines of any dosage form, evidence of safety or harm, bioavailability, patient experience, tolerability, contamination and comparison of methods of manipulation were included. Case studies and letters were excluded. Fifty studies were eligible for inclusion, 49 of which involved tablets being cut, split, crushed or dispersed. The remaining one study involved the manipulation of suppositories of one drug. No eligible studies concerning manipulation of oral capsules or liquids, rectal enemas, nebuliser solutions, injections or transdermal patches were identified. Twenty four of the tablet studies considered dose accuracy using weight and/or drug content. In studies that considered weight using adapted pharmacopoeial specifications, the percentage of halved tablets meeting these specifications ranged from 30% to 100%. Eighteen studies investigated bioavailability, pharmacokinetics or clinical outcomes following manipulations which included nine delayed or modified release formulations. In each of these nine studies the entirety of the dosage form was administered. Only one of the 18 studies was identified where drugs were manipulated to obtain a proportion of the dosage form, and that proportion administered. The five studies that considered patient perception found that having to manipulate the tablets did not have a negative impact on adherence. Of the 49 studies only two studies reported investigating children. This review yielded limited evidence to support manipulation of medicines for children. The results cannot be extrapolated between dosage forms, methods of manipulation or between different brands of the same

  3. Mapping Ecosystem Services: An Integrated Biophysical and Economic Evaluation

    OpenAIRE

    Hayha, T.

    2014-01-01

    Forests provide a wide range of ecosystem services, from timber and non-wood products (provisioning services) to carbon sequestration, hydrogeological protection (regulating services), and recreation and aesthetic experiences (cultural services). Nonmarketed forest ecosystem services tend to be undervalued due to the lack of a market price and a clear understanding of their vital support to socio-economic systems. Ecosystem services are interlinked, and therefore the optimization of one typol...

  4. Identification of ecosystem parameters by SDE-modelling

    DEFF Research Database (Denmark)

    Stochastic differential equations (SDEs) for ecosystem modelling have attracted increasing attention during recent years. The modelling has mostly been through simulation experiments in order to analyse how system noise propagates through the ordinary differential equation formulation of ecosystem...... models. Estimation of parameters in SDEs is, however, possible by combining Kalman filter techniques and likelihood estimation. By modelling parameters as random walks it is possible to identify linear as well as non-linear interactions between ecosystem components. By formulating a simple linear SDE...

  5. The role of recurrent disturbances for ecosystem multifunctionality.

    Science.gov (United States)

    Villnäs, Anna; Norkko, Joanna; Hietanen, Susanna; Josefson, Alf B; Lukkari, Kaarina; Norkko, Alf

    2013-10-01

    Ecosystem functioning is threatened by an increasing number of anthropogenic stressors, creating a legacy of disturbance that undermines ecosystem resilience. However, few empirical studies have assessed to what extent an ecosystem can tolerate repeated disturbances and sustain its multiple functions. By inducing increasingly recurring hypoxic disturbances to a sedimentary ecosystem, we show that the majority of individual ecosystem functions experience gradual degradation patterns in response to repetitive pulse disturbances. The degradation in overall ecosystem functioning was, however, evident at an earlier stage than for single ecosystem functions and was induced after a short pulse of hypoxia (i.e., three days), which likely reduced ecosystem resistance to further hypoxic perturbations. The increasing number of repeated pulse disturbances gradually moved the system closer to a press response. In addition to the disturbance regime, the changes in benthic trait composition as well as habitat heterogeneity were important for explaining the variability in overall ecosystem functioning. Our results suggest that disturbance-induced responses across multiple ecosystem functions can serve as a warning signal for losses of the adaptive capacity of an ecosystem, and might at an early stage provide information to managers and policy makers when remediation efforts should be initiated.

  6. Manipulation or Mobilisation for Neck Pain

    NARCIS (Netherlands)

    Gross, Anita; Miller, Jordan; D'Sylva, Jonathan; Burnie, Stephen J.; Goldsmith, Charles H.; Graham, Nadine; Haines, Ted; Brønfort, Gert; Hoving, Jan L.

    2010-01-01

    Background Manipulation and mobilisation are often used, either alone or combined with other treatment approaches, to treat neck pain. Objectives To assess if manipulation or mobilisation improves pain, function/disability, patient satisfaction, quality of life, and global perceived effect in adults

  7. Analysis of singularity in redundant manipulators

    International Nuclear Information System (INIS)

    Watanabe, Koichi

    2000-03-01

    In the analysis of arm positions and configurations of redundant manipulators, the singularity avoidance problems are important themes. This report presents singularity avoidance computations of a 7 DOF manipulator by using a computer code based on human-arm models. The behavior of the arm escaping from the singular point can be identified satisfactorily through the use of 3-D plotting tools. (author)

  8. Managing collaboration in the nanoManipulator

    DEFF Research Database (Denmark)

    Hudson, Thomas C.; Helser, Aren T.; Sonnenwald, Diane H.

    2004-01-01

    We designed, developed, deployed, and evaluated the Collaborative nanoManipulator (CnM), a distributed, collaborative virtual environment system supporting remote scientific collaboration between users of the nanoManipulator interface to atomic force microscopes. This paper describes the entire...

  9. Even Middle Graders Can Learn with Manipulatives.

    Science.gov (United States)

    Holden, Linda

    1987-01-01

    Math manipulatives let students see the components of an abstract problem, help build a concrete language for talking about math concepts, and encourage students to gain confidence in their ability to figure things out. Many suggestions for using manipulatives in math instruction are offered. (MT)

  10. Lazy motion planning for robotic manipulators

    NARCIS (Netherlands)

    Andrien, A.R.P.; van de Molengraft, M.J.G.; Bruyninckx, H.P.J.

    2017-01-01

    Robotic manipulators are making a shift towards mobile bases in both industry and domestic environments, which puts high demands on efficient use of the robot’s limited energy resources. In this work, the problem of reducing energy usage of a robot manipulator during a task is investigated. We

  11. Judging Nudging : Answering the Manipulation Objection

    NARCIS (Netherlands)

    Nys, Thomas; Engelen, Bart

    2017-01-01

    Is it ever justified to ‘nudge’ people towards their own health? In this article, we argue that it is. We do so by arguing (1) that nudges are not necessarily – as is commonly thought – manipulative; (2) that even those nudges that are manipulative can be justified, for instance, when they preserve

  12. Tools for Manipulation and Characterisation of Nanostructures

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Bøggild, Peter

    grippers, which were then successfully used for pick-and-place manipulation of silicon nanowires. For increased gripping force and control over the manipulation process, microfabricated grippers with integrated force-feedback were also demonstrated. Environmental electron beam deposition (EEBD...... components that are some 10000 times smaller....

  13. Wetland plant influence on sediment ecosystem structure and trophic function

    OpenAIRE

    Whitcraft, Christine René

    2007-01-01

    Vascular plants structure wetland ecosystems. To examine mechanisms behind their influence, plants were studied under different scenarios of change: experimental manipulation of cover, invasion, and response to flushing regimes. I tested the hypothesis that wetland plants alter benthic communities through modification of abiotic factors, with cascading effects on microalgae and invertebrate communities. Major plant effects were observed in all systems studied, but the magnitude of, mechanisms...

  14. Manipulating Liquids With Acoustic Radiation Pressure Phased Arrays

    Science.gov (United States)

    Oeftering, Richard C.

    1999-01-01

    High-intensity ultrasound waves can produce the effects of "Acoustic Radiation Pressure" (ARP) and "acoustic streaming." These effects can be used to propel liquid flows and to apply forces that can be used to move or manipulate floating objects or liquid surfaces. NASA's interest in ARP includes the remote-control agitation of liquids and the manipulation of bubbles and drops in liquid experiments and propellant systems. A high level of flexibility is attained by using a high-power acoustic phased array to generate, steer, and focus a beam of acoustic waves. This is called an Acoustic Radiation Pressure Phased Array, or ARPPA. In this approach, many acoustic transducer elements emit wavelets that converge into a single beam of sound waves. Electronically coordinating the timing, or "phase shift," of the acoustic waves makes it possible to form a beam with a predefined direction and focus. Therefore, a user can direct the ARP force at almost any desired point within a liquid volume. ARPPA lets experimenters manipulate objects anywhere in a test volume. This flexibility allow it to be used for multiple purposes, such as to agitate liquids, deploy and manipulate drops or bubbles, and even suppress sloshing in spacecraft propellant tanks.

  15. MEMS 6 degrees of freedom parallel micro manipulator for TEM sample manipulation

    NARCIS (Netherlands)

    Brouwer, Dannis Michel; de Jong, B.R.; Soemers, Herman

    2005-01-01

    Up till now MEMS actuators acted either only in-plane or only out-of plane restricting to 3 DOF manipulation. A design for a millimeter-sized manipulator with 6 degrees of freedom to manipulate a micron-sized substrate at nanometer resolution over strokes of 10 microns with a position stability

  16. Interaction control of a redundant mobile manipulator

    International Nuclear Information System (INIS)

    Chung, J.H.; Velinsky, S.A.; Hess, R.A.

    1998-01-01

    This paper discusses the modeling and control of a spatial mobile manipulator that consists of a robotic manipulator mounted on a wheeled mobile platform. The Lagrange-d'Alembert formulation is used to obtain a concise description of the dynamics of the system, which is subject to nonholonomic constraints. The complexity of the model is increased by introducing kinematic redundancy, which is created when a multilinked manipulator is used. The kinematic redundancy is resolved by decomposing the mobile manipulator into two subsystems: the mobile platform and the manipulator. The redundancy resolution scheme employs a nonlinear interaction-control algorithm, which is developed and applied to coordinate the two subsystems' controllers. The subsystem controllers are independently designed, based on each subsystem's dynamic characteristics. Simulation results show the promise of the developed algorithm

  17. Maximum allowable load on wheeled mobile manipulators

    International Nuclear Information System (INIS)

    Habibnejad Korayem, M.; Ghariblu, H.

    2003-01-01

    This paper develops a computational technique for finding the maximum allowable load of mobile manipulator during a given trajectory. The maximum allowable loads which can be achieved by a mobile manipulator during a given trajectory are limited by the number of factors; probably the dynamic properties of mobile base and mounted manipulator, their actuator limitations and additional constraints applied to resolving the redundancy are the most important factors. To resolve extra D.O.F introduced by the base mobility, additional constraint functions are proposed directly in the task space of mobile manipulator. Finally, in two numerical examples involving a two-link planar manipulator mounted on a differentially driven mobile base, application of the method to determining maximum allowable load is verified. The simulation results demonstrates the maximum allowable load on a desired trajectory has not a unique value and directly depends on the additional constraint functions which applies to resolve the motion redundancy

  18. Laser Diode Beam Basics, Manipulations and Characterizations

    CERN Document Server

    Sun, Haiyin

    2012-01-01

    Many optical design technical books are available for many years which mainly deal with image optics design based on geometric optics and using sequential raytracing technique. Some books slightly touched laser beam manipulation optics design. On the other hand many books on laser diodes have been published that extensively deal with laser diode physics with little touching on laser diode beam manipulations and characterizations. There are some internet resources dealing with laser diode beams. However, these internet resources have not covered enough materials with enough details on laser diode beam manipulations and characterizations. A technical book concentrated on laser diode beam manipulations and characterizations can fit in to the open and provide useful information to laser diode users. Laser Diode Beam Basics, Manipulations and  Characterizations is concentrated on the very practical side of the subject, it only discusses the basic physics and mathematics that are necessary for the readers in order...

  19. Monetary accounting of ecosystem services

    NARCIS (Netherlands)

    Remme, R.P.; Edens, Bram; Schröter, Matthias; Hein, Lars

    2015-01-01

    Ecosystem accounting aims to provide a better understanding of ecosystem contributions to the economy in a spatially explicit way. Ecosystem accounting monitors ecosystem services and measures their monetary value using exchange values consistent with the System of National Accounts (SNA). We

  20. The role of ants, birds and bats for ecosystem functions and yield in oil palm plantations.

    Science.gov (United States)

    Denmead, Lisa H; Darras, Kevin; Clough, Yann; Diaz, Patrick; Grass, Ingo; Hoffmann, Munir P; Nurdiansyah, Fuad; Fardiansah, Rico; Tscharntke, Teja

    2017-07-01

    One of the world's most important and rapidly expanding crops, oil palm, is associated with low levels of biodiversity. Changes in predator communities might alter ecosystem services and subsequently sustainable management but these links have received little attention to date. Here, for the first time, we manipulated ant and flying vertebrate (birds and bats) access to oil palms in six smallholder plantations in Sumatra (Indonesia) and measured effects on arthropod communities, related ecosystem functions (herbivory, predation, decomposition and pollination) and crop yield. Arthropod predators increased in response to reductions in ant and bird access, but the overall effect of experimental manipulations on ecosystem functions was minimal. Similarly, effects on yield were not significant. We conclude that ecosystem functions and productivity in oil palm are, under current levels of low pest pressure and large pollinator populations, robust to large reductions of major predators. © 2017 by the Ecological Society of America.

  1. Kinematics Modelling of Tendon-Driven Continuum Manipulator with Crossed Notches

    Science.gov (United States)

    Yang, Z. X.; Yang, W. L.; Du, Z. J.

    2018-03-01

    Single port surgical robot (SPSR) is a giant leap in the development of minimally invasive surgical robot. An innovative manipulator with high control accuracy and good kinematic dexterity can reduce wound, expedite recovery, and improve the success rate. This paper presents a tendon-driven continuum manipulator with crossed notches. This manipulator has two degrees of freedom (DOF), which possesses good flexibility and high capacity. Then based on cantilever beam theory, a mechanics model is proposed, which connects external force and deformation of a single flexible ring (SFR). By calculating the deformation of each SFR, the manipulator is considered as a series robot whose joint numbers is equal to SFR numbers, and the kinematics model is established through Denavit-Hartenberg (D-H) procedure. In this paper, the total manipulator is described as a curve tube whose curvature is increased from tip to base. Experiments were conducted and the comparison between theoretical and actual results proved the rationality of the models.

  2. The Comparative Effectiveness of Physical, Virtual, and Virtual-Physical Manipulatives on Third-Grade Students' Science Achievement and Conceptual Understanding of Evaporation and Condensation

    Science.gov (United States)

    Wang, Tzu-Ling; Tseng, Yi-Kuan

    2018-01-01

    The purpose of this study was to investigate the relative effectiveness of experimenting with physical manipulatives alone, virtual manipulatives alone, and virtual preceding physical manipulatives (combination environment) on third-grade students' science achievement and conceptual understanding in the domain of state changes of water, focusing…

  3. Manipulation and quantification of microtubule lattice integrity

    Directory of Open Access Journals (Sweden)

    Taylor A. Reid

    2017-08-01

    Full Text Available Microtubules are structural polymers that participate in a wide range of cellular functions. The addition and loss of tubulin subunits allows the microtubule to grow and shorten, as well as to develop and repair defects and gaps in its cylindrical lattice. These lattice defects act to modulate the interactions of microtubules with molecular motors and other microtubule-associated proteins. Therefore, tools to control and measure microtubule lattice structure will be invaluable for developing a quantitative understanding of how the structural state of the microtubule lattice may regulate its interactions with other proteins. In this work, we manipulated the lattice integrity of in vitro microtubules to create pools of microtubules with common nucleotide states, but with variations in structural states. We then developed a series of novel semi-automated analysis tools for both fluorescence and electron microscopy experiments to quantify the type and severity of alterations in microtubule lattice integrity. These techniques will enable new investigations that explore the role of microtubule lattice structure in interactions with microtubule-associated proteins.

  4. Consistent Performance Differences between Children and Adults Despite Manipulation of Cue-Target Variables

    Directory of Open Access Journals (Sweden)

    Jessie-Raye Bauer

    2017-08-01

    Full Text Available Two behavioral experiments assessed the plasticity and short-term improvement of task switching in 215 children and adults. Specifically, we studied manipulations of cued attention to different features of a target stimulus as a way to assess the development of cognitive flexibility. Each experiment had multiple levels of difficulty via manipulation of number of cued features (2–4 and number of response options (2 or 4. Working memory demand was manipulated across the two experiments. Impact of memory demand and task level manipulations on task accuracy and response times were measured. There were three overall goals: First, these task manipulations (number of cued features, response choices, and working memory load were tested to assess the stability of group differences in performance between children ages 6–16 years and adults 18–27 years, with the goal of reducing age group differences. Second, age-related transitions to adult-level performance were examined within subgroups of the child sample. Third, short-term improvement from the beginning to the end of the study session was measured to probe whether children can improve with task experience. Attempts to use task manipulations to reduce age differences in cued task switching performance were unsuccessful: children performed consistently worse and were more susceptible to task manipulations than adults. However, across both studies, adult-like performance was observed around mid-adolescence, by ages 13-16 years. Certain task manipulations, especially increasing number of response options when working memory demand was low, produced differences from adults even in the oldest children. Interestingly, there was similar performance improvement with practice for both child and adult groups. The higher memory demand version of the task (Experiment 2 prompted greater short-term improvement in accuracy and response times than the lower memory demand version (Experiment 1. These results

  5. Object manipulation facilitates kind-based object individuation of shape-similar objects

    DEFF Research Database (Denmark)

    Kingo, Osman Skjold; Krøjgaard, Peter

    2011-01-01

    Five experiments investigated the importance of shape and object manipulation when 12-month-olds were given the task of individuating objects representing exemplars of kinds in an event-mapping design. In Experiments 1 and 2, results of the study from Xu, Carey, and Quint (2004, Experiment 4) wer...

  6. Rapid top-down regulation of plant C:N:P stoichiometry by grasshoppers in an Inner Mongolia grassland ecosystem.

    Science.gov (United States)

    Zhang, Guangming; Han, Xingguo; Elser, James J

    2011-05-01

    Understanding how food web interactions alter the processing of limiting nutrient elements is an important goal of ecosystem ecology. An experiment manipulating densities of the grasshopper Oedaleus asiaticus was performed to assess top-down effects of grasshoppers on C:N:P stoichiometry of plants and soil in a grassland ecosystem in Inner Mongolia (China). With increased grasshopper feeding, plant biomass declined fourfold, litter abundance increased 30%, and the plant community became dominated by non-host plant taxa. Plant stoichiometric response depended on whether or not the plant was a grasshopper host food species: C:N and C:P ratios increased with increasing grasshopper density (GD) for host plants but decreased in non-host plants. These data suggest either a direct transfer of grasshopper-recycled nutrients from host to non-host plants or a release of non-host plants from nutrient competition with heavily grazed host plants. Litterfall C:N and C:P decreased across moderate levels of grasshopper density but no effects on C:N:P stoichiometry in the surface soil were observed, possibly due to the short experimental period. Our observations of divergent C:N:P stoichiometric response among plant species highlight the important role of grasshopper herbivory in regulating plant community structure and nutrient cycling in grassland ecosystems.

  7. Hydraulic manipulator design, analysis, and control at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.; Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States); Basher, A.M.H. [South Carolina State Univ., Orangeburg, SC (United States)

    1996-09-01

    To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned to hydraulics as a means of actuation. Hydraulics have always been the actuator of choice when designing heavy-life construction and mining equipment such as bulldozers, backhoes, and tunneling devices. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem) sophisticated modeling, analysis, and control experiments are usually needed. To support the development and deployment of new hydraulic manipulators Oak Ridge National Laboratory (ORNL) has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The hydraulics laboratory at ORNL has three different manipulators. First is a 6-Degree-of-Freedom (6-DoF), multi-planer, teleoperated, flexible controls test bed used for the development of waste tank clean-up manipulator controls, thermal studies, system characterization, and manipulator tracking. Finally, is a human amplifier test bed used for the development of an entire new class of teleoperated systems. To compliment the hardware in the hydraulics laboratory, ORNL has developed a hydraulics simulation capability including a custom package to model the hydraulic systems and manipulators for performance studies and control development. This paper outlines the history of hydraulic manipulator developments at ORNL, describes the hydraulics laboratory, discusses the use of the equipment within the laboratory, and presents some of the initial results from experiments and modeling associated with these hydraulic manipulators. Included are some of the results from the development of the human amplifier/de-amplifier concepts, the characterization of the thermal sensitivity of hydraulic systems, and end-point tracking accuracy studies. Experimental and analytical

  8. Hydraulic manipulator design, analysis, and control at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Kress, R.L.; Jansen, J.F.; Basher, A.M.H.

    1996-09-01

    To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned to hydraulics as a means of actuation. Hydraulics have always been the actuator of choice when designing heavy-life construction and mining equipment such as bulldozers, backhoes, and tunneling devices. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem) sophisticated modeling, analysis, and control experiments are usually needed. To support the development and deployment of new hydraulic manipulators Oak Ridge National Laboratory (ORNL) has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The hydraulics laboratory at ORNL has three different manipulators. First is a 6-Degree-of-Freedom (6-DoF), multi-planer, teleoperated, flexible controls test bed used for the development of waste tank clean-up manipulator controls, thermal studies, system characterization, and manipulator tracking. Finally, is a human amplifier test bed used for the development of an entire new class of teleoperated systems. To compliment the hardware in the hydraulics laboratory, ORNL has developed a hydraulics simulation capability including a custom package to model the hydraulic systems and manipulators for performance studies and control development. This paper outlines the history of hydraulic manipulator developments at ORNL, describes the hydraulics laboratory, discusses the use of the equipment within the laboratory, and presents some of the initial results from experiments and modeling associated with these hydraulic manipulators. Included are some of the results from the development of the human amplifier/de-amplifier concepts, the characterization of the thermal sensitivity of hydraulic systems, and end-point tracking accuracy studies. Experimental and analytical

  9. Expert operator preferences in remote manipulator control systems

    International Nuclear Information System (INIS)

    Sundstrom, E.; Draper, J.V.; Fausz, A.; Woods, H.

    1995-06-01

    This report describes a survey of expert remote manipulator operators designed to identify features of control systems related to operator efficiency and comfort. It provides information for designing the control center for the Single-Shell Tank Waste Retrieval Manipulator System (TWRMS) Test Bed, described in a separate report. Research questions concerned preferred modes of control, optimum work sessions, sources of operator fatigue, importance of control system design features, and desired changes in control rooms. Participants comprised four expert remote manipulator operators at Oak Ridge National Laboratory, who individually have from 9 to 20 years of experience using teleoperators. The operators had all used rate and position control, and all preferred bilateral (force-reflecting) position control. They reported spending an average of 2.75 h in control of a teleoperator system during a typical shift. All were accustomed to working in a crew of two and alternating control and support roles in 2-h rotations in an 8-h shift. Operators reported that fatigue in using remote manipulator systems came mainly from watching TV monitors and making repetitive motions. Three of four experienced symptoms, including headaches and sore eyes, wrists, and back. Of 17 features of control rooms rated on importance, highest ratings went to comfort and support provided by the operator chair, location of controls, location of video monitors, video image clarity, types of controls, and control modes. When asked what they wanted to change, operators said work stations designed for comfort; simpler, lighter hand-controls; separate controls for each camera; better placement of remote camera; color monitors; and control room layouts that support crew interaction. Results of this small survey reinforced the importance of ergonomic factors in remote manipulation

  10. SWFSC/MMTD/CCE: Oregon, California, and Washington Line-transect Experiment (ORCAWALE) 1996, 2001, 2008 and CA Current Cetacean and Ecosystem Assessment Survey (CalCurCEAS) 2014

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The California Current Cetacean and Ecosystem Assessment Survey (CalCurCEAS) is a marine mammal assessment survey of the U.S. West Coast waters. Similar research in...

  11. Task based synthesis of serial manipulators

    Directory of Open Access Journals (Sweden)

    Sarosh Patel

    2015-05-01

    Full Text Available Computing the optimal geometric structure of manipulators is one of the most intricate problems in contemporary robot kinematics. Robotic manipulators are designed and built to perform certain predetermined tasks. There is a very close relationship between the structure of the manipulator and its kinematic performance. It is therefore important to incorporate such task requirements during the design and synthesis of the robotic manipulators. Such task requirements and performance constraints can be specified in terms of the required end-effector positions, orientations and velocities along the task trajectory. In this work, we present a comprehensive method to develop the optimal geometric structure (DH parameters of a non-redundant six degree of freedom serial manipulator from task descriptions. In this work we define, develop and test a methodology to design optimal manipulator configurations based on task descriptions. This methodology is devised to investigate all possible manipulator configurations that can satisfy the task performance requirements under imposed joint constraints. Out of all the possible structures, the structures that can reach all the task points with the required orientations are selected. Next, these candidate structures are tested to see whether they can attain end-effector velocities in arbitrary directions within the user defined joint constraints, so that they can deliver the best kinematic performance. Additionally least power consuming configurations are also identified.

  12. Dimensions of ecosystem theory

    International Nuclear Information System (INIS)

    O'Neill, R.V.; Reichle, D.E.

    1979-01-01

    Various dimensions of ecosystem structure and behavior that seem to develop from the ubiquitous phenomena of system growth and persistence were studied. While growth and persistence attributes of ecosystems may appear to be simplistic phenomena upon which to base a comprehensive ecosystem theory, these same attributes have been fundamental to the theoretical development of other biological disciplines. These attributes were explored at a hierarchical level in a self-organizing system, and adaptive system strategies that result were analyzed. Previously developed causative relations (Reichle et al., 1975c) were examined, their theoretical implications expounded upon, and the assumptions tested with data from a variety of forest types. The conclusions are not a theory in themselves, but a state of organization of concepts contributing towards a unifying theory, along the lines promulgated by Bray (1958). The inferences drawn rely heavily upon data from forested ecosystems of the world, and have yet to be validated against data from a much more diverse range of ecosystem types. Not all of the interpretations are logically tight - there is room for other explanations, which it is hoped will provide fruitful grounds for further speculation

  13. Applications of optical manipulation in plant biology

    Science.gov (United States)

    Buer, Charles S.

    Measuring small forces in biology is important for determining basic physiological parameters of a cell. The plant cell wall provides a primary defense and presents a barrier to research. Magnitudes of small forces are impossible to measure with mechanical transducers, glass needles, atomic force microscopy, or micropipet-based force transduction due to the cell wall. Therefore, a noninvasive method of breaching the plant cell wall to access the symplastic region of the cell is required. Laser light provides sub-micrometer positioning, particle manipulation without mechanical contact, and piconewton force determination. Consequently, the extension of laser microsurgery to expand an experimental tool for plant biology encompassed the overall objective. A protocol was developed for precisely inserting microscopic objects into the periplasmic region of plant callus cells using laser microsurgery. Ginkgo biloba and Agrobacterium rhizogenes were used as the model system for developing the optical tweezers and scalpel techniques. Better than 95% survival was achieved after plasmolyzing G. biloba cells, ablating a 2-4 μm hole through the cell wall using a pulsed UV laser beam, trapping and manipulating bacteria into the periplasmic region, and deplasmolyzing the cells. Optical trapping experiments implied a difference existed between the bacteria models. Determining the optical trapping efficiency of Agrobacterium rhizogenes and A. tumefaciens strains indicated the A. rhizogenes strain, ATCC 11325, was significantly less efficiently trapped than strains A4 and ATCC 15834 and the A. tumefaciens strain LBA4404. Differences were also found in capsule generation, growth media viscosity, and transmission electron microscopy negative staining implying that a difference in surface structure exists. Calcofluor fluorescence suggests the difference involves an exopolysaccharide. Callus cell plasmolysis revealed Hechtian strands interconnecting the plasma membrane and the cell wall

  14. Pneumatic artificial muscle actuators for compliant robotic manipulators

    Science.gov (United States)

    Robinson, Ryan Michael

    Robotic systems are increasingly being utilized in applications that require interaction with humans. In order to enable safe physical human-robot interaction, light weight and compliant manipulation are desirable. These requirements are problematic for many conventional actuation systems, which are often heavy, and typically use high stiffness to achieve high performance, leading to large impact forces upon collision. However, pneumatic artificial muscles (PAMs) are actuators that can satisfy these safety requirements while offering power-to-weight ratios comparable to those of conventional actuators. PAMs are extremely lightweight actuators that produce force in response to pressurization. These muscles demonstrate natural compliance, but have a nonlinear force-contraction profile that complicates modeling and control. This body of research presents solutions to the challenges associated with the implementation of PAMs as actuators in robotic manipulators, particularly with regard to modeling, design, and control. An existing PAM force balance model was modified to incorporate elliptic end geometry and a hyper-elastic constitutive relationship, dramatically improving predictions of PAM behavior at high contraction. Utilizing this improved model, two proof-of-concept PAM-driven manipulators were designed and constructed; design features included parallel placement of actuators and a tendon-link joint design. Genetic algorithm search heuristics were employed to determine an optimal joint geometry; allowing a manipulator to achieve a desired torque profile while minimizing the required PAM pressure. Performance of the manipulators was evaluated in both simulation and experiment employing various linear and nonlinear control strategies. These included output feedback techniques, such as proportional-integral-derivative (PID) and fuzzy logic, a model-based control for computed torque, and more advanced controllers, such as sliding mode, adaptive sliding mode, and

  15. Ecosystem Vulnerability Review: Proposal of an Interdisciplinary Ecosystem Assessment Approach

    Science.gov (United States)

    Weißhuhn, Peter; Müller, Felix; Wiggering, Hubert

    2018-06-01

    To safeguard the sustainable use of ecosystems and their services, early detection of potentially damaging changes in functional capabilities is needed. To support a proper ecosystem management, the analysis of an ecosystem's vulnerability provide information on its weaknesses as well as on its capacity to recover after suffering an impact. However, the application of the vulnerability concept to ecosystems is still an emerging topic. After providing background on the vulnerability concept, we summarize existing ecosystem vulnerability research on the basis of a systematic literature review with a special focus on ecosystem type, disciplinary background, and more detailed definition of the ecosystem vulnerability components. Using the Web of ScienceTM Core Collection, we overviewed the literature from 1991 onwards but used the 5 years from 2011 to 2015 for an in-depth analysis, including 129 articles. We found that ecosystem vulnerability analysis has been applied most notably in conservation biology, climate change research, and ecological risk assessments, pinpointing a limited spreading across the environmental sciences. It occurred primarily within marine and freshwater ecosystems. To avoid confusion, we recommend using the unambiguous term ecosystem vulnerability rather than ecological, environmental, population, or community vulnerability. Further, common ground has been identified, on which to define the ecosystem vulnerability components exposure, sensitivity, and adaptive capacity. We propose a framework for ecosystem assessments that coherently connects the concepts of vulnerability, resilience, and adaptability as different ecosystem responses. A short outlook on the possible operationalization of the concept by ecosystem vulnerabilty indices, and a conclusion section complete the review.

  16. Adaptive hidden Markov model with anomaly States for price manipulation detection.

    Science.gov (United States)

    Cao, Yi; Li, Yuhua; Coleman, Sonya; Belatreche, Ammar; McGinnity, Thomas Martin

    2015-02-01

    Price manipulation refers to the activities of those traders who use carefully designed trading behaviors to manually push up or down the underlying equity prices for making profits. With increasing volumes and frequency of trading, price manipulation can be extremely damaging to the proper functioning and integrity of capital markets. The existing literature focuses on either empirical studies of market abuse cases or analysis of particular manipulation types based on certain assumptions. Effective approaches for analyzing and detecting price manipulation in real time are yet to be developed. This paper proposes a novel approach, called adaptive hidden Markov model with anomaly states (AHMMAS) for modeling and detecting price manipulation activities. Together with wavelet transformations and gradients as the feature extraction methods, the AHMMAS model caters to price manipulation detection and basic manipulation type recognition. The evaluation experiments conducted on seven stock tick data from NASDAQ and the London Stock Exchange and 10 simulated stock prices by stochastic differential equation show that the proposed AHMMAS model can effectively detect price manipulation patterns and outperforms the selected benchmark models.

  17. Experimental design of multifactor climate change experiments with elevated CO2, warming and drought: the CLIMAITE project

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Beier, Claus; Jonasson, S.

    2008-01-01

    a larger set of main factors are needed. We describe a new Danish climate change-related field scale experiment, CLIMAITE, in a heath/grassland ecosystem. CLIMAITE is a full factorial combination of elevated CO2, elevated temperature and prolonged summer drought. The manipulations are intended to mimic...... anticipated major environmental changes at the site by year 2075 as closely as possible. The impacts on ecosystem processes and functioning (at ecophysiological levels, through responses by individuals and communities to ecosystem-level responses) are investigated simultaneously. The increase of [CO2] closely...... corresponds with the scenarios for year 2075, while the warming treatment is at the lower end of the predictions and seems to be the most difficult treatment to increase without unwanted side effects on the other variables. The drought treatment follows predictions of increased frequency of drought periods...

  18. Completion of the Heysham 2 peripheral manipulator

    International Nuclear Information System (INIS)

    Shipp, R.; Ewen, R.O.

    1996-01-01

    The in-service inspection strategy for the AGR power station at Heysham 2 envisaged a suite of five manipulators to be used for inserting TRIUMPH television cameras into the reactor vessel. Prior to power raising, four of the five had been successfully commissioned and have been in regular use during the subsequent statutory outages. The final device, the Peripheral Manipulator (PM), was eventually completed prior to the 1994 outage and has been successfully deployed on reactor for both the 1994 and 1995 outages. The paper describes the design of the manipulator, its operation and scope of use in the Heysham 2 reactors. (Author)

  19. W-026, acceptance test report manipulator system

    International Nuclear Information System (INIS)

    Watson, T.L.

    1997-01-01

    The purpose of the WRAP Manipulator System Acceptance Test Plan (ATP) is to verify that the 4 glovebox sets of WRAP manipulator components, including rail/carriage, slave arm, master controller and auxiliary equipment, meets the requirements of the functional segments of 14590 specification. The demonstration of performance elements of the ATP are performed as a part of the Assembly specifications. Manipulator integration is integrated in the performance testing of the gloveboxes. Each requirement of the Assembly specification will be carried out in conjunction with glovebox performance tests

  20. Interpersonal relationship manipulation at a personal level

    OpenAIRE

    Andreja Hribernik

    2010-01-01

    Manipulation is not unknown or strange to any of us. We have all experienced it, or perhaps even practiced it. It is wrong not to recognize it, to find excuses for it, and, above all, it is wrong not to decide to change one’s behaviour. Long-lasting use of manipulation leaves consequences on all the parties involved: the victim, the observer and the perpetrator. Manipulation is a relation between persons which does not consider the needs of everybody involved. It means exploitation and mislea...

  1. Development of the heavy manipulator vehicle system

    International Nuclear Information System (INIS)

    Herbst, C.; Paustian, P.; Kruger, W.

    1993-01-01

    After the severe reactor accident of Tschernobyl in 1986 MaK System started to develop a Heavy Manipulator Vehicle System under contract from German nuclear technology assistance company ''KHG'' (Kerntechnische Hilfsdienst GmbH). The system comprises a remote controlled manipulator vehicle, a mobile mission control stand as well as a transport/service unit. In order to fulfill the high demands of this complex system a couple of new developments had to be started. The paper describes some of these developments and gives an overview about the main features of the Heavy Manipulator Vehicle System (HMV). (author)

  2. Working group 7: Ecosystems

    International Nuclear Information System (INIS)

    Verheyen, R.

    1976-01-01

    The purpose of this article is to evaluate the environmental impact of nuclear power plants. The effects of ionizing radiations, of the thermal and chemical pollution on aquatic ecosystems as well as on terrestrial ecosystems have been estimated. After a general survey of such effects and their interaction, practical conclusions in regard to determined areas such as Meuse-Escaut marine and the coast have been drawn. The contamination effects of food chains have been evaluted under deliberately pessimistic conditions with regard to the choice of the radionuclide as well as of concentration factors. Following the biodegradation conditions of the surface waters, criteria for the quality of the aquatic ecosystems have been established. Finally, attention has been paid on certain factors affecting the site selection especially within the frame of the nature conservation. The effects of cooling towers have been also considered. (G.C.)

  3. Sea Ice Ecosystems

    Science.gov (United States)

    Arrigo, Kevin R.

    2014-01-01

    Polar sea ice is one of the largest ecosystems on Earth. The liquid brine fraction of the ice matrix is home to a diverse array of organisms, ranging from tiny archaea to larger fish and invertebrates. These organisms can tolerate high brine salinity and low temperature but do best when conditions are milder. Thriving ice algal communities, generally dominated by diatoms, live at the ice/water interface and in recently flooded surface and interior layers, especially during spring, when temperatures begin to rise. Although protists dominate the sea ice biomass, heterotrophic bacteria are also abundant. The sea ice ecosystem provides food for a host of animals, with crustaceans being the most conspicuous. Uneaten organic matter from the ice sinks through the water column and feeds benthic ecosystems. As sea ice extent declines, ice algae likely contribute a shrinking fraction of the total amount of organic matter produced in polar waters.

  4. A novel magnetorheological damper based parallel planar manipulator design

    International Nuclear Information System (INIS)

    Hoyle, A; Arzanpour, S; Shen, Y

    2010-01-01

    This paper presents a novel parallel planar robot design which is low cost and simple in structure. The design addresses some of the problems, such as concentration of excessive load on the links and joints, due to wrong commanding signals being given by the controller. In this application two of the conventional actuators are replaced by magnetorheological (MR) dampers, and only one actuator is used to generate motion. The design paradigm is based on the concept that a moving object 'intuitively' follows the path with minimum resistance to its motion. This implies that virtual adoptable constraints can be used effectively to define motion trajectories. In fact, motion generation and adaptive constraints are two elements essential to implementing this strategy. In this paper, MR dampers are used to provide adjustable constraints and to guide the platform that is moved by the linear motor. The model of the MR dampers is derived using the Bouc–Wen model. This model is then used for manipulator simulation and controller design. Two controllers are developed for this manipulator: (1) a closed loop on/off one and (2) a proportional–derivative controller. Also, three different trajectories are defined and used for both the simulations and experiments. The results indicate a good agreement between the simulations and experiments. The experimental results also demonstrate the capability of the manipulator for following sophisticated trajectories

  5. Ferromagnetic nanostructures by laser manipulation

    NARCIS (Netherlands)

    Bosch, R.C.M.

    2002-01-01

    Lithography based on laser focusing of a beam of neutral iron atoms shows great promise for creating nanomagnetic structures. Laser focusing is a relatively new area, where successful experiments have been performed with, e.g., chromium atoms. Iron is perhaps one of the most difficult elements for

  6. Rain forest nutrient cycling and productivity in response to large-scale litter manipulation.

    Science.gov (United States)

    Wood, Tana E; Lawrence, Deborah; Clark, Deborah A; Chazdon, Robin L

    2009-01-01

    Litter-induced pulses of nutrient availability could play an important role in the productivity and nutrient cycling of forested ecosystems, especially tropical forests. Tropical forests experience such pulses as a result of wet-dry seasonality and during major climatic events, such as strong El Niños. We hypothesized that (1) an increase in the quantity and quality of litter inputs would stimulate leaf litter production, woody growth, and leaf litter nutrient cycling, and (2) the timing and magnitude of this response would be influenced by soil fertility and forest age. To test these hypotheses in a Costa Rican wet tropical forest, we established a large-scale litter manipulation experiment in two secondary forest sites and four old-growth forest sites of differing soil fertility. In replicated plots at each site, leaves and twigs (forest floor. We analyzed leaf litter mass, [N] and [P], and N and P inputs for addition, removal, and control plots over a two-year period. We also evaluated basal area increment of trees in removal and addition plots. There was no response of forest productivity or nutrient cycling to litter removal; however, litter addition significantly increased leaf litter production and N and P inputs 4-5 months following litter application. Litter production increased as much as 92%, and P and N inputs as much as 85% and 156%, respectively. In contrast, litter manipulation had no significant effect on woody growth. The increase in leaf litter production and N and P inputs were significantly positively related to the total P that was applied in litter form. Neither litter treatment nor forest type influenced the temporal pattern of any of the variables measured. Thus, environmental factors such as rainfall drive temporal variability in litter and nutrient inputs, while nutrient release from decomposing litter influences the magnitude. Seasonal or annual variation in leaf litter mass, such as occurs in strong El Niño events, could positively

  7. [The essence of Professor Wu Lian-Zhong's acupuncture manipulation].

    Science.gov (United States)

    Liu, Jing; Guo, Yi; Wu, Lian-Zhong

    2014-05-01

    The painless needle insertion technique, summarized by Professor WU Lian-zhong during his decades of acupuncture clinical practice is introduced in this article, which is characterized as soft, flexible, fast, plucking and activating antipathogenic qi. The Sancai (three layers) lifting and thrusting manipulation technique is adopted by Professor WU for getting the qi sensation. And features of 10 kinds of needling sensation such as soreness, numbness, heaviness, distension, pain, cold, hot, radiation, jumping and contracture are summarized. Finger force, amplitude, speed and time length are also taken as the basis of reinforcing and reducing manipulations. Moreover, examples are also given to explain the needling technique on some specific points which further embodies Professor WU's unique experiences and understandings on acupuncture.

  8. The morality of assisted reproduction and genetic manipulation

    Directory of Open Access Journals (Sweden)

    Mori Maurizio

    1999-01-01

    Full Text Available The author analyzes the pros and cons of various forms of assisted reproduction, including the use of so-called 'genetic manipulation'. He shows how in ethics the only arguments with any chance of reaching a consensus (or at least an agreement are those of the rational type, based on universally acceptable ethical principles or corroborated by empirical facts and real life experience (as the starting point for identifying problems requiring analysis. After an analysis in which he identifies the incoherence and inconsistency of arguments against assisted reproduction, the author defends the right of human beings to decide autonomously about the most healthy forms of procreation, including those involving genetic manipulation. His starting point is the moral principle by which it is morally preferable to intervene in natural processes (as opposed to not intervening whenever this implies preventing and reducing disease and suffering

  9. The morality of assisted reproduction and genetic manipulation

    Directory of Open Access Journals (Sweden)

    Maurizio Mori

    Full Text Available The author analyzes the pros and cons of various forms of assisted reproduction, including the use of so-called 'genetic manipulation'. He shows how in ethics the only arguments with any chance of reaching a consensus (or at least an agreement are those of the rational type, based on universally acceptable ethical principles or corroborated by empirical facts and real life experience (as the starting point for identifying problems requiring analysis. After an analysis in which he identifies the incoherence and inconsistency of arguments against assisted reproduction, the author defends the right of human beings to decide autonomously about the most healthy forms of procreation, including those involving genetic manipulation. His starting point is the moral principle by which it is morally preferable to intervene in natural processes (as opposed to not intervening whenever this implies preventing and reducing disease and suffering

  10. Mechatronic Model Based Computed Torque Control of a Parallel Manipulator

    Directory of Open Access Journals (Sweden)

    Zhiyong Yang

    2008-11-01

    Full Text Available With high speed and accuracy the parallel manipulators have wide application in the industry, but there still exist many difficulties in the actual control process because of the time-varying and coupling. Unfortunately, the present-day commercial controlles cannot provide satisfying performance for its single axis linear control only. Therefore, aimed at a novel 2-DOF (Degree of Freedom parallel manipulator called Diamond 600, a motor-mechanism coupling dynamic model based control scheme employing the computed torque control algorithm are presented in this paper. First, the integrated dynamic coupling model is deduced, according to equivalent torques between the mechanical structure and the PM (Permanent Magnetism servomotor. Second, computed torque controller is described in detail for the above proposed model. At last, a series of numerical simulations and experiments are carried out to test the effectiveness of the system, and the results verify the favourable tracking ability and robustness.

  11. Mechatronic Model Based Computed Torque Control of a Parallel Manipulator

    Directory of Open Access Journals (Sweden)

    Zhiyong Yang

    2008-03-01

    Full Text Available With high speed and accuracy the parallel manipulators have wide application in the industry, but there still exist many difficulties in the actual control process because of the time-varying and coupling. Unfortunately, the present-day commercial controlles cannot provide satisfying performance for its single axis linear control only. Therefore, aimed at a novel 2-DOF (Degree of Freedom parallel manipulator called Diamond 600, a motor-mechanism coupling dynamic model based control scheme employing the computed torque control algorithm are presented in this paper. First, the integrated dynamic coupling model is deduced, according to equivalent torques between the mechanical structure and the PM (Permanent Magnetism servomotor. Second, computed torque controller is described in detail for the above proposed model. At last, a series of numerical simulations and experiments are carried out to test the effectiveness of the system, and the results verify the favourable tracking ability and robustness.

  12. Autonomous Task Primitives for Complex Manipulation Operations

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this research effort is to enable robots to autonomously perform the complex manipulation tasks that are necessary to maintain a spacecraft. Robots, like...

  13. Reconfigurable mobile manipulation for accident response

    International Nuclear Information System (INIS)

    Anderson, Robert J.; Morse, William D.; Shirey, David L.; Cdebaca, DanielL M.; Hoffman, John P. Jr.; Lucy, William E.

    2000-01-01

    The need for a telerobotic vehicle with hazard sensing and integral manipulation capabilities has been identified for use in transportation accidents where nuclear weapons are involved. The Accident Response Mobile Manipulation System (ARMMS) platform has been developed to provide remote dexterous manipulation and hazard sensing for the Accident Response Group (ARG) at Sandia National Laboratories. The ARMMS' mobility platform is a military HMMWV [High Mobility Multipurpose Wheeled Vehicle] that is teleoperated over RF or Fiber Optic communication channels. ARMMS is equipped with two high strength Schilling Titan II manipulators and a suite of hazardous gas and radiation sensors. Recently, a modular telerobotic control architecture call SMART (Sandia Modular Architecture for Robotic and Teleoperation) has been applied to ARMMS. SMART enables input devices and many system behaviors to be rapidly configured in the field for specific mission needs. This paper summarizes current SMART developments applied to ARMMS

  14. Spinal Manipulation for Low-Back Pain

    Science.gov (United States)

    ... V W X Y Z Spinal Manipulation for Low-Back Pain Share: On This Page Introduction Key Points About ... will help ensure coordinated and safe care. About Low-Back Pain Back pain is one of the most common ...

  15. Analysis, reconstruction and manipulation using arterial snakes

    KAUST Repository

    Li, Guo; Liu, Ligang; Zheng, Hanlin; Mitra, Niloy J.

    2010-01-01

    , and manipulating such arterial surfaces. The core of the algorithm is a novel deformable model, called arterial snake, that simultaneously captures the topology and geometry of the arterial objects. The recovered snakes produce a natural decomposition of the raw

  16. Disrupting reconsolidation: pharmacological and behavioral manipulations

    NARCIS (Netherlands)

    Soeter, M.; Kindt, M.

    2011-01-01

    We previously demonstrated that disrupting reconsolidation by pharmacological manipulations "deleted" the emotional expression of a fear memory in humans. If we are to target reconsolidation in patients with anxiety disorders, the disruption of reconsolidation should produce content-limited

  17. ADVERTISING AS MEAN OF MANIPULATION OF PEOPLE

    Directory of Open Access Journals (Sweden)

    Camelia PAVEL

    2014-04-01

    Full Text Available The article provides a number of issues involved in defining manipulation, because both in the current language as in the specialty literature, the manipulation notion is used with multiple significations, often contradictory ones, and that it’s not firmly delimited by other notions from the same sphere, like persuasion or propaganda. The aim of the article will be, in the end, removing ambiguity that surrounds this concept and offering a better understanding of its very real effects on human lives. We advance and sustain the hypothesis that manipulation is an illegitimate process, justified by the structure of the human conscience and by the mechanisms of the social life. In addition, the paper provides a concrete example of manipulation of public through advertising contracts offered by Roşia Montană Gold Corporation. Finally conclusions were outlined.

  18. Optoelectronic Tweezers for Microparticle and Cell Manipulation

    Science.gov (United States)

    Wu, Ming Chiang (Inventor); Chiou, Pei-Yu (Inventor); Ohta, Aaron T. (Inventor)

    2014-01-01

    An optical image-driven light induced dielectrophoresis (DEP) apparatus and method are described which provide for the manipulation of particles or cells with a diameter on the order of 100 micromillimeters or less. The apparatus is referred to as optoelectric tweezers (OET) and provides a number of advantages over conventional optical tweezers, in particular the ability to perform operations in parallel and over a large area without damage to living cells. The OET device generally comprises a planar liquid-filled structure having one or more portions which are photoconductive to convert incoming light to a change in the electric field pattern. The light patterns are dynamically generated to provide a number of manipulation structures that can manipulate single particles and cells or group of particles/cells. The OET preferably includes a microscopic imaging means to provide feedback for the optical manipulation, such as detecting position and characteristics wherein the light patterns are modulated accordingly.

  19. Tension Stiffened and Tendon Actuated Manipulator

    Science.gov (United States)

    Doggett, William R. (Inventor); Dorsey, John T. (Inventor); Ganoe, George G. (Inventor); King, Bruce D. (Inventor); Jones, Thomas C. (Inventor); Mercer, Charles D. (Inventor); Corbin, Cole K. (Inventor)

    2015-01-01

    A tension stiffened and tendon actuated manipulator is provided performing robotic-like movements when acquiring a payload. The manipulator design can be adapted for use in-space, lunar or other planetary installations as it is readily configurable for acquiring and precisely manipulating a payload in both a zero-g environment and in an environment with a gravity field. The manipulator includes a plurality of link arms, a hinge connecting adjacent link arms together to allow the adjacent link arms to rotate relative to each other and a cable actuation and tensioning system provided between adjacent link arms. The cable actuation and tensioning system includes a spreader arm and a plurality of driven and non-driven elements attached to the link arms and the spreader arm. At least one cable is routed around the driven and non-driven elements for actuating the hinge.

  20. Vibration control of an artificial muscle manipulator with a magnetorheological fluid brake

    Science.gov (United States)

    Tomori, H.; Midorikawa, Y.; Nakamura, T.

    2013-02-01

    Recently, proposed applications of robots require them to contact human safely. Therefore, we focus on pneumatic rubber artificial muscle. This actuator is flexible, light, and has high-power density. However, because the artificial muscle is flexible, it vibrates when there is a high load. Therefore, we paid attention to the magnetorheological (MR) fluid. We propose a control method of the MR brake considering energy of the manipulator system. By this control method, MR brake dissipates energy leading to vibration of the manipulator. In this paper, we calculated the energy and controlled the MR brake. And, we deliberated the proposal method by simulation using the dynamic model of the manipulator, and experiment.