Belowground Interactions Impact the Soil Bacterial Community, Soil Fertility, and Crop Yield in Maize/Peanut Intercropping Systems

Directory of Open Access Journals (Sweden)

Qisong Li

2018-02-01

Full Text Available Intercropping has been widely used to control disease and improve yield in agriculture. In this study, maize and peanut were used for non-separation intercropping (NS, semi-separation intercropping (SS using a nylon net, and complete separation intercropping (CS using a plastic sheet. In field experiments, two-year land equivalent ratios (LERs showed yield advantages due to belowground interactions when using NS and SS patterns as compared to monoculture. In contrast, intercropping without belowground interactions (CS showed a yield disadvantage. Meanwhile, in pot experiments, belowground interactions (found in NS and SS improved levels of soil-available nutrients (nitrogen (N and phosphorus (P and enzymes (urease and acid phosphomonoesterase as compared to intercropping without belowground interactions (CS. Soil bacterial community assay showed that soil bacterial communities in the NS and SS crops clustered together and were considerably different from the CS crops. The diversity of bacterial communities was significantly improved in soils with NS and SS. The abundance of beneficial bacteria, which have the functions of P-solubilization, pathogen suppression, and N-cycling, was improved in maize and peanut soils due to belowground interactions through intercropping. Among these bacteria, numbers of Bacillus, Brevibacillus brevis, and Paenibacillus were mainly increased in the maize rhizosphere. Burkholderia, Pseudomonas, and Rhizobium were mainly increased in the peanut rhizosphere. In conclusion, using maize and peanut intercropping, belowground interactions increased the numbers of beneficial bacteria in the soil and improved the diversity of the bacterial community, which was conducive to improving soil nutrient (N and P supply capacity and soil microecosystem stability.

Ecosystem carbon partitioning: aboveground net primary productivity correlates with the root carbon input in different land use types of Southern Alps

Science.gov (United States)

Rodeghiero, Mirco; Martinez, Cristina; Gianelle, Damiano; Camin, Federica; Zanotelli, Damiano; Magnani, Federico

2013-04-01

Terrestrial plant carbon partitioning to above- and below-ground compartments can be better understood by integrating studies on biomass allocation and estimates of root carbon input based on the use of stable isotopes. These experiments are essential to model ecosystem's metabolism and predict the effects of global change on carbon cycling. Using in-growth soil cores in conjunction with the 13C natural abundance method we quantified net plant-derived root carbon input into the soil, which has been pointed out as the main unaccounted NPP (net primary productivity) component. Four land use types located in the Trentino Region (northern Italy) and representing a range of aboveground net primary productivity (ANPP) values (155-868 gC m-2 y-1) were investigated: conifer forest, apple orchard, vineyard and grassland. Cores, filled with soil of a known C4 isotopic signature were inserted at 18 sampling points for each site and left in place for twelve months. After extraction, cores were analysed for %C and d13C, which were used to calculate the proportion of new plant-derived root C input by applying a mass balance equation. The GPP (gross primary productivity) of each ecosystem was determined by the eddy covariance technique whereas ANPP was quantified with a repeated inventory approach. We found a strong and significant relationship (R2 = 0.93; p=0.03) between ANPP and the fraction of GPP transferred to the soil as root C input across the investigated sites. This percentage varied between 10 and 25% of GPP with the grassland having the lowest value and the apple orchard the highest. Mechanistic ecosystem carbon balance models could benefit from this general relationship since ANPP is routinely and easily measured at many sites. This result also suggests that by quantifying site-specific ANPP, root carbon input can be reliably estimated, as opposed to using arbitrary root/shoot ratios which may under- or over-estimate C partitioning.

Global net primary production and heterotrophic respiration for 1987

Energy Technology Data Exchange (ETDEWEB)

Hunt, R.E. Jr.; Piper, S.C.; Nemani, R. [Univ. of Montana, Missoula, MT (United States)]|[Scripps Institute of Oceanography, La Jolla, CA (United States)] [and others

1995-06-01

An ecosystem process model, BIOME-BGC, was parameterized and used to simulate the actual net primary production and heterotrophic respiration using daily climatic data, land cover type, leaf area index gridded to 1{degree} latitude by 1{degree} longitude grid cells for the year 1987. Global net primary production was 52 Pg C. These estimates were validated directly by two different methods. First, the grid cells were aggregated and used as inputs to a 3D atmospheric transport model, to compare CO{sub 2} station data with predictions. We simulated the intra-annual variation of atmospheric CO{sub 2} well for the northern hemisphere, but not for the southern hemisphere. Second, we calculated the net {sup 13}C uptake of vegetation, which is a function of water use efficiency. The {sup 13}C/{sup 12}C ratios agreed with measured data, indicating a strong limitation of global primary processes by the hydrologic cycle, especially precipitation. These are different from other global carbon models as we can simulate the year-to-year variation of climate, including El Nino, on the global carbon cycle.

Global climate change and above- belowground insect herbivore interactions.

Directory of Open Access Journals (Sweden)

Scott Wesley McKenzie

2013-10-01

Full Text Available Predicted changes to the Earth’s climate are likely to affect above-belowground interactions. Our understanding is limited, however, by past focus on two-species aboveground interactions mostly ignoring belowground influences. Despite their importance to ecosystem processes, there remains a dearth of empirical evidence showing how climate change will affect above-belowground interactions. The responses of above- and belowground organisms to climate change are likely to differ given the fundamentally different niches they inhabit. Yet there are few studies that address the biological and ecological reactions of belowground herbivores to environmental conditions in current and future climates. Even fewer studies investigate the consequences of climate change for above-belowground interactions between herbivores and other organisms; those that do provide no evidence of a directed response. This paper highlights the importance of considering the belowground fauna when making predictions on the effects of climate change on plant-mediated interspecific interactions.

HANPP Collection: Global Patterns in Human Appropriation of Net Primary Productivity (HANPP)

Data.gov (United States)

National Aeronautics and Space Administration — The Global Patterns in Human Appropriation of Net Primary Productivity (HANPP) portion of the HANPP Collection represents a digital map of human appropriation of net...

Aboveground mechanical stimuli affect belowground plant-plant communication.

Science.gov (United States)

Elhakeem, Ali; Markovic, Dimitrije; Broberg, Anders; Anten, Niels P R; Ninkovic, Velemir

2018-01-01

Plants can detect the presence of their neighbours and modify their growth behaviour accordingly. But the extent to which this neighbour detection is mediated by abiotic stressors is not well known. In this study we tested the acclimation response of Zea mays L. seedlings through belowground interactions to the presence of their siblings exposed to brief mechano stimuli. Maize seedling simultaneously shared the growth solution of touched plants or they were transferred to the growth solution of previously touched plants. We tested the growth preferences of newly germinated seedlings toward the growth solution of touched (T_solution) or untouched plants (C_solution). The primary root of the newly germinated seedlings grew significantly less towards T_solution than to C_solution. Plants transferred to T_solution allocated more biomass to shoots and less to roots. While plants that simultaneously shared their growth solution with the touched plants produced more biomass. Results show that plant responses to neighbours can be modified by aboveground abiotic stress to those neighbours and suggest that these modifications are mediated by belowground interactions.

Aboveground mechanical stimuli affect belowground plant-plant communication.

Directory of Open Access Journals (Sweden)

Ali Elhakeem

Full Text Available Plants can detect the presence of their neighbours and modify their growth behaviour accordingly. But the extent to which this neighbour detection is mediated by abiotic stressors is not well known. In this study we tested the acclimation response of Zea mays L. seedlings through belowground interactions to the presence of their siblings exposed to brief mechano stimuli. Maize seedling simultaneously shared the growth solution of touched plants or they were transferred to the growth solution of previously touched plants. We tested the growth preferences of newly germinated seedlings toward the growth solution of touched (T_solution or untouched plants (C_solution. The primary root of the newly germinated seedlings grew significantly less towards T_solution than to C_solution. Plants transferred to T_solution allocated more biomass to shoots and less to roots. While plants that simultaneously shared their growth solution with the touched plants produced more biomass. Results show that plant responses to neighbours can be modified by aboveground abiotic stress to those neighbours and suggest that these modifications are mediated by belowground interactions.

HANPP Collection: Human Appropriation of Net Primary Productivity (HANPP) by Country and Product

Data.gov (United States)

National Aeronautics and Space Administration — The Global Patterns in Human Appropriation of Net Primary Productivity (HANPP) portion of the HANPP Collection represents a digital map of human appropriation of net...

Belowground Plant Dynamics Across an Arctic Landscape

Science.gov (United States)

Salmon, V. G.; Iversen, C. M.; Breen, A. L.; Thornton, P. E.; Wullschleger, S.

2017-12-01

High-latitude ecosystems are made up of a mosaic of different plant communities, all of which are exposed to warming at a rate double that observed in ecosystems at lower latitudes. Arctic regions are an important component of global Earth system models due to the large amounts of soil carbon (C) currently stored in permafrost as well their potential for increased plant C sequestration under warmer conditions. Losses of C from thawing and decomposing permafrost may be offset by increased plant productivity, but plant allocation to belowground structures and acquisition of limiting nutrients remain key sources of uncertainty in these ecosystems. The relationship between belowground plant traits and environmental conditions is not well understood, nor are tradeoffs between above- and belowground plant traits. To address these knowledge gaps, we sampled above- and belowground plant tissues along the Kougarok Hillslope on the Seward Peninsula, Alaska. The vegetation communities sampled included Alder shrubland, willow birch tundra, tussock tundra, dwarf shrub lichen tundra, and non-acidic mountain complex. Within each plant community, aboveground biomass was quantified and specific leaf area, leaf chemistry (%C, %N, %P and δ15N), and wood density were measured. Belowground fine-root biomass and rooting depth distribution were also determined at the community level. Fine roots from shrubs and graminoids were separated so that specific root area, diameter, and chemistry (%C, %N, %P and δ15N) could be assessed for these contrasting plant functional types. Initial findings indicate fine root biomass pools across the widely varying plant communities are constrained by soil depth, regardless of whether the rooting zone is restricted by permafrost or rock. The presence of Alnus viridis subspp. fruticosa, a deciduous shrub that facilitates nitrogen (N) fixation within its root nodules by Frankia bacteria, in Alder shrubland and willow birch tundra communities was associated

Site-level evaluation of satellite-based global terrestrial gross primary production and net primary production monitoring.

Science.gov (United States)

David P. Turner; William D. Ritts; Warren B. Cohen; Thomas K. Maeirsperger; Stith T. Gower; Al A. Kirschbaum; Steve W. Runnings; Maosheng Zhaos; Steven C. Wofsy; Allison L. Dunn; Beverly E. Law; John L. Campbell; Walter C. Oechel; Hyo Jung Kwon; Tilden P. Meyers; Eric E. Small; Shirley A. Kurc; John A. Gamon

2005-01-01

Operational monitoring of global terrestrial gross primary production (GPP) and net primary production (NPP) is now underway using imagery from the satellite-borne Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Evaluation of MODIS GPP and NPP products will require site-level studies across a range of biomes, with close attention to numerous scaling...

The impacts of climate change and belowground herbivory on aphids via primary metabolites

Science.gov (United States)

Ryalls, James M. W.

CO2 and simulated root damage on aphids could be explained by changes in plant amino acid concentrations. Chapter five built on the mechanistic findings from chapter four to determine whether specific groups of amino acids were responsible for driving the effects of eT and eCO2 on aphid fecundity, longevity and intrinsic rate of increase (rm). Chapter six extended this research to the field to determine the plant-mediated effects of water stress and root herbivory on aphids in a mixed grass-legume system. Lucerne demonstrated an over compensatory growth response to root herbivory by S. discoideus larvae by increasing net root biomass and nodulation by 31% and 45%, respectively. eT negated the positive effects of eCO2 on weevil larval development, as well as on a number of lucerne characteristics (e.g. nodulation and amino acid concentrations) and aphid performance parameters (e.g. population growth, fecundity and rm). Root herbivory by S. discoideus negatively impacted aphids in general, although effects were dependent on feeding duration and herbivore arrival sequence (i.e. whether aphids fed on the plant before or after root herbivory). While drought negatively impacted aphid abundance, potentially via reduced phloem turgor and sap viscosity, the effects of eT, eCO2 and root herbivory on aphids were often driven by concentrations of specific amino acid groups. Nitrogen (N) leached from lacerated lucerne root nodules by S. discoideus led to increased concentrations of N in a neighbouring grass, Phalaris aquatica (Poaceae), with knock-on effects on plant competition and community dynamics. The opposing effects of eT and eCO2 on plant characteristics and both aboveground and belowground herbivores demonstrates the importance of combining trophic complexity with multiple climatic factors as a means of gaining realistic insights into how insect and plant communities will respond under future conditions. Identifying the specific amino acid changes underpinning aphid

Interactions between above- and belowground organisms modified in climate change experiments

Science.gov (United States)

Stevnbak, Karen; Scherber, Christoph; Gladbach, David J.; Beier, Claus; Mikkelsen, Teis N.; Christensen, Søren

2012-11-01

Climate change has been shown to affect ecosystem process rates and community composition, with direct and indirect effects on belowground food webs. In particular, altered rates of herbivory under future climate can be expected to influence above-belowground interactions. Here, we use a multifactor, field-scale climate change experiment and independently manipulate atmospheric CO2 concentration, air and soil temperature and drought in all combinations since 2005. We show that changes in these factors modify the interaction between above- and belowground organisms. We use an insect herbivore to experimentally increase aboveground herbivory in grass phytometers exposed to all eight combinations of climate change factors for three years. Aboveground herbivory increased the abundance of belowground protozoans, microbial growth and microbial nitrogen availability. Increased CO2 modified these links through a reduction in herbivory and cascading effects through the soil food web. Interactions between CO2, drought and warming can affect belowground protozoan abundance. Our findings imply that climate change affects aboveground-belowground interactions through changes in nutrient availability.

Interactions between above- and belowground organisms modified in climate change experiments

DEFF Research Database (Denmark)

Stevnsbak, Karen; Scherber, Christoph; Gladbach, David

2012-01-01

Climate change has been shown to affect ecosystem process rates and community composition, with direct and indirect effects on belowground food webs. In particular, altered rates of herbivory under future climate4 can be expected to influence above–belowground interactions. Here, we use...... a multifactor, field-scale climate change experiment and independently manipulate atmospheric CO2 concentration, air and soil temperature and drought in all combinations since 2005. We show that changes in these factors modify the interaction between above- and belowground organisms.We use an insect herbivore...... a reduction in herbivory and cascading effects through the soil food web. Interactions between CO2, drought and warming can affect belowground protozoan abundance. Our findings imply that climate change affects aboveground–belowground interactions through changes in nutrient availability....

Unearthing belowground bud banks in fire-prone ecosystems.

Science.gov (United States)

Pausas, Juli G; Lamont, Byron B; Paula, Susana; Appezzato-da-Glória, Beatriz; Fidelis, Alessandra

2018-03-01

Despite long-time awareness of the importance of the location of buds in plant biology, research on belowground bud banks has been scant. Terms such as lignotuber, xylopodium and sobole, all referring to belowground bud-bearing structures, are used inconsistently in the literature. Because soil efficiently insulates meristems from the heat of fire, concealing buds below ground provides fitness benefits in fire-prone ecosystems. Thus, in these ecosystems, there is a remarkable diversity of bud-bearing structures. There are at least six locations where belowground buds are stored: roots, root crown, rhizomes, woody burls, fleshy swellings and belowground caudexes. These support many morphologically distinct organs. Given their history and function, these organs may be divided into three groups: those that originated in the early history of plants and that currently are widespread (bud-bearing roots and root crowns); those that also originated early and have spread mainly among ferns and monocots (nonwoody rhizomes and a wide range of fleshy underground swellings); and those that originated later in history and are strictly tied to fire-prone ecosystems (woody rhizomes, lignotubers and xylopodia). Recognizing the diversity of belowground bud banks is the starting point for understanding the many evolutionary pathways available for responding to severe recurrent disturbances. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Impacts of tropospheric ozone and climate change on net primary productivity and net carbon exchange of China’s forest ecosystems

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Wei Ren; Hanqin Tian; Bo Tao; Art Chappelka; Ge Sun; et al

2011-01-01

Aim We investigated how ozone pollution and climate change/variability have interactively affected net primary productivity (NPP) and net carbon exchange (NCE) across China’s forest ecosystem in the past half century. Location Continental China. Methods Using the dynamic land ecosystem model (DLEM) in conjunction with 10-km-resolution gridded historical data sets (...

Eliciting maize defense pathways aboveground attracts belowground biocontrol agents.

Science.gov (United States)

Filgueiras, Camila Cramer; Willett, Denis S; Pereira, Ramom Vasconcelos; Moino Junior, Alcides; Pareja, Martin; Duncan, Larry W

2016-11-04

Plant defense pathways mediate multitrophic interactions above and belowground. Understanding the effects of these pathways on pests and natural enemies above and belowground holds great potential for designing effective control strategies. Here we investigate the effects of aboveground stimulation of plant defense pathways on the interactions between corn, the aboveground herbivore adult Diabrotica speciosa, the belowground herbivore larval D. speciosa, and the subterranean ento-mopathogenic nematode natural enemy Heterorhabditis amazonensis. We show that adult D. speciosa recruit to aboveground herbivory and methyl salicylate treatment, that larval D. speciosa are relatively indiscriminate, and that H. amazonensis en-tomopathogenic nematodes recruit to corn fed upon by adult D. speciosa. These results suggest that entomopathogenicnematodes belowground can be highly attuned to changes in the aboveground parts of plants and that biological control can be enhanced with induced plant defense in this and similar systems.

Eliciting maize defense pathways aboveground attracts belowground biocontrol agents

Science.gov (United States)

Filgueiras, Camila Cramer; Willett, Denis S.; Pereira, Ramom Vasconcelos; Moino Junior, Alcides; Pareja, Martin; Duncan, Larry W.

2016-01-01

Plant defense pathways mediate multitrophic interactions above and belowground. Understanding the effects of these pathways on pests and natural enemies above and belowground holds great potential for designing effective control strategies. Here we investigate the effects of aboveground stimulation of plant defense pathways on the interactions between corn, the aboveground herbivore adult Diabrotica speciosa, the belowground herbivore larval D. speciosa, and the subterranean ento-mopathogenic nematode natural enemy Heterorhabditis amazonensis. We show that adult D. speciosa recruit to aboveground herbivory and methyl salicylate treatment, that larval D. speciosa are relatively indiscriminate, and that H. amazonensis en-tomopathogenic nematodes recruit to corn fed upon by adult D. speciosa. These results suggest that entomopathogenicnematodes belowground can be highly attuned to changes in the aboveground parts of plants and that biological control can be enhanced with induced plant defense in this and similar systems. PMID:27811992

Short-Term Belowground Responses to Thinning and Burning Treatments in Southwestern Ponderosa Pine Forests of the USA

Directory of Open Access Journals (Sweden)

Steven T. Overby

2016-02-01

Full Text Available Microbial-mediated decomposition and nutrient mineralization are major drivers of forest productivity. As landscape-scale fuel reduction treatments are being implemented throughout the fire-prone western United States of America, it is important to evaluate operationally how these wildfire mitigation treatments alter belowground processes. We quantified these important belowground components before and after management-applied fuel treatments of thinning alone, thinning combined with prescribed fire, and prescribed fire in ponderosa pine (Pinus ponderosa stands at the Southwest Plateau, Fire and Fire Surrogate site, Arizona. Fuel treatments did not alter pH, total carbon and nitrogen (N concentrations, or base cations of the forest floor (O horizon or mineral soil (0–5 cm during this 2-year study. In situ rates of net N mineralization and nitrification in the surface mineral soil (0–15 cm increased 6 months after thinning with prescribed fire treatments; thinning only resulted in net N immobilization. The rates returned to pre-treatment levels after one year. Based on phospholipid fatty acid composition, microbial communities in treated areas were similar to untreated areas (control in the surface organic horizon and mineral soil (0–5 cm after treatments. Soil potential enzyme activities were not significantly altered by any of the three fuel treatments. Our results suggest that a variety of one-time alternative fuel treatments can reduce fire hazard without degrading soil fertility.

Detection of unknown primary neuroendocrine tumours (CUP-NET) using 68Ga-DOTA-NOC receptor PET/CT

International Nuclear Information System (INIS)

Prasad, Vikas; Baum, Richard P.; Ambrosini, Valentina; Fanti, Stefano; Hommann, Merten; Hoersch, Dieter

2010-01-01

This bi-centric study aimed to determine the role of receptor PET/CT using 68 Ga-DOTA-NOC in the detection of undiagnosed primary sites of neuroendocrine tumours (NETs) and to understand the molecular behaviour of the primarily undiagnosed tumours. Overall 59 patients (33 men and 26 women, age: 65 ± 9 years) with documented NET and unknown primary were enrolled. PET/CT was performed after injection of approximately 100 MBq (46-260 MBq) of 68 Ga-DOTA-NOC. The maximum standardised uptake values (SUV max ) were calculated and compared with SUV max in known pancreatic NET (pNET) and ileum/jejunum/duodenum (SI-NET). The results of PET/CT were also correlated with CT alone. In 35 of 59 patients (59%), 68 Ga-DOTA-NOC PET/CT localised the site of the primary: ileum/jejunum (14), pancreas (16), rectum/colon (2), lungs (2) and paraganglioma (1). CT alone (on retrospective analyses) confirmed the findings in 12 of 59 patients (20%). The mean SUV max of identified previously unknown pNET and SI-NET were 18.6 ± 9.8 (range: 7.8-34.8) and 9.1 ± 6.0 (range: 4.2-27.8), respectively. SUV max in patients with previously known pNET and SI-NET were 26.1 ± 14.5 (range: 8.7-42.4) and 11.3 ± 3.7 (range: 5.6-17.9). The SUV max of the unknown pNET and SI-NET were significantly lower (p 68 Ga-DOTA-NOC receptor PET/CT, 6 of 59 patients were operated and the primary was removed (4 pancreatic, 1 ileal and 1 rectal tumour) resulting in a management change in approximately 10% of the patients. In the remaining 29 patients, because of the far advanced stage of the disease (due to distant metastases), the primary tumours were not operated. Additional histopathological sampling was available from one patient with bronchial carcinoid (through bronchoscopy). Our data indicate that 68 Ga-DOTA-NOC PET/CT is highly superior to 111 In-OctreoScan (39% detection rate for CUP according to the literature) and can play a major role in the management of patients with CUP-NET. (orig.)

Quantifying above- and belowground biomass carbon loss with forest conversion in tropical lowlands of Sumatra (Indonesia).

Science.gov (United States)

Kotowska, Martyna M; Leuschner, Christoph; Triadiati, Triadiati; Meriem, Selis; Hertel, Dietrich

2015-10-01

Natural forests in South-East Asia have been extensively converted into other land-use systems in the past decades and still show high deforestation rates. Historically, lowland forests have been converted into rubber forests, but more recently, the dominant conversion is into oil palm plantations. While it is expected that the large-scale conversion has strong effects on the carbon cycle, detailed studies quantifying carbon pools and total net primary production (NPPtotal ) in above- and belowground tree biomass in land-use systems replacing rainforest (incl. oil palm plantations) are rare so far. We measured above- and belowground carbon pools in tree biomass together with NPPtotal in natural old-growth forests, 'jungle rubber' agroforests under natural tree cover, and rubber and oil palm monocultures in Sumatra. In total, 32 stands (eight plot replicates per land-use system) were studied in two different regions. Total tree biomass in the natural forest (mean: 384 Mg ha(-1) ) was more than two times higher than in jungle rubber stands (147 Mg ha(-1) ) and >four times higher than in monoculture rubber and oil palm plantations (78 and 50 Mg ha(-1) ). NPPtotal was higher in the natural forest (24 Mg ha(-1)  yr(-1) ) than in the rubber systems (20 and 15 Mg ha(-1)  yr(-1) ), but was highest in the oil palm system (33 Mg ha(-1)  yr(-1) ) due to very high fruit production (15-20 Mg ha(-1)  yr(-1) ). NPPtotal was dominated in all systems by aboveground production, but belowground productivity was significantly higher in the natural forest and jungle rubber than in plantations. We conclude that conversion of natural lowland forest into different agricultural systems leads to a strong reduction not only in the biomass carbon pool (up to 166 Mg C ha(-1) ) but also in carbon sequestration as carbon residence time (i.e. biomass-C:NPP-C) was 3-10 times higher in the natural forest than in rubber and oil palm plantations. © 2015 John Wiley & Sons Ltd.

Increased light-use efficiency sustains net primary productivity of shaded coffee plants in agroforestry system.

Science.gov (United States)

Charbonnier, Fabien; Roupsard, Olivier; le Maire, Guerric; Guillemot, Joannès; Casanoves, Fernando; Lacointe, André; Vaast, Philippe; Allinne, Clémentine; Audebert, Louise; Cambou, Aurélie; Clément-Vidal, Anne; Defrenet, Elsa; Duursma, Remko A; Jarri, Laura; Jourdan, Christophe; Khac, Emmanuelle; Leandro, Patricia; Medlyn, Belinda E; Saint-André, Laurent; Thaler, Philippe; Van Den Meersche, Karel; Barquero Aguilar, Alejandra; Lehner, Peter; Dreyer, Erwin

2017-08-01

In agroforestry systems, shade trees strongly affect the physiology of the undergrown crop. However, a major paradigm is that the reduction in absorbed photosynthetically active radiation is, to a certain extent, compensated by an increase in light-use efficiency, thereby reducing the difference in net primary productivity between shaded and non-shaded plants. Due to the large spatial heterogeneity in agroforestry systems and the lack of appropriate tools, the combined effects of such variables have seldom been analysed, even though they may help understand physiological processes underlying yield dynamics. In this study, we monitored net primary productivity, during two years, on scales ranging from individual coffee plants to the entire plot. Absorbed radiation was mapped with a 3D model (MAESPA). Light-use efficiency and net assimilation rate were derived for each coffee plant individually. We found that although irradiance was reduced by 60% below crowns of shade trees, coffee light-use efficiency increased by 50%, leaving net primary productivity fairly stable across all shade levels. Variability of aboveground net primary productivity of coffee plants was caused primarily by the age of the plants and by intraspecific competition among them (drivers usually overlooked in the agroforestry literature) rather than by the presence of shade trees. © 2017 John Wiley & Sons Ltd.

Spatial variation in tuber depletion by swans explained by differences in net intake rates

NARCIS (Netherlands)

Nolet, BA; Langevoord, O; Bevan, RM; Engelaar, KR; Klaassen, M; Mulder, RJW

We tested whether the spatial variation in resource depletion by Tundra Swans (Cygnus columbianus) foraging on belowground tubers of sage pondweed (Potnmogeton pectinatus) was caused by differences in net energy intake rates. The variation in giving up densities within the confines of one lake was

Plant neighbour identity matters to belowground interactions under controlled conditions.

Science.gov (United States)

Armas, Cristina; Pugnaire, Francisco Ignacio

2011-01-01

Root competition is an almost ubiquitous feature of plant communities with profound effects on their structure and composition. Far beyond the traditional view that plants interact mainly through resource depletion (exploitation competition), roots are known to be able to interact with their environment using a large variety of mechanisms that may inhibit or enhance access of other roots to the resource or affect plant growth (contest interactions). However, an extensive analysis on how these contest root interactions may affect species interaction abilities is almost lacking. In a common garden experiment with ten perennial plant species we forced pairs of plants of the same or different species to overlap their roots and analyzed how belowground contest interactions affected plant performance, biomass allocation patterns, and competitive abilities under abundant resource supply. Our results showed that net interaction outcome ranged from negative to positive, affecting total plant mass and allocation patterns. A species could be a strong competitor against one species, weaker against another one, and even facilitator to a third species. This leads to sets of species where competitive hierarchies may be clear but also to groups where such rankings are not, suggesting that intransitive root interactions may be crucial for species coexistence. The outcome of belowground contest interactions is strongly dependent on neighbours' identity. In natural plant communities this conditional outcome may hypothetically help species to interact in non-hierarchical and intransitive networks, which in turn might promote coexistence.

Comparison of modeling approaches for carbon partitioning: Impact on estimates of global net primary production and equilibrium biomass of woody vegetation from MODIS GPP

Science.gov (United States)

Takeshi Ise; Creighton M. Litton; Christian P. Giardina; Akihiko Ito

2010-01-01

Partitioning of gross primary production (GPP) to aboveground versus belowground, to growth versus respiration, and to short versus long�]lived tissues exerts a strong influence on ecosystem structure and function, with potentially large implications for the global carbon budget. A recent meta-analysis of forest ecosystems suggests that carbon partitioning...

Detection of unknown primary neuroendocrine tumours (CUP-NET) using {sup 68}Ga-DOTA-NOC receptor PET/CT

Energy Technology Data Exchange (ETDEWEB)

Prasad, Vikas; Baum, Richard P. [Zentralklinik Bad Berka, Department of Nuclear Medicine and Centre for PET/CT, Bad Berka (Germany); Ambrosini, Valentina; Fanti, Stefano [University of Bologna, Nuclear Medicine Unit, Policlinico S. Orsola-Malpighi, Bologna (Italy); Hommann, Merten [Zentralklinik Bad Berka, Department of General and Visceral Surgery, Bad Berka (Germany); Hoersch, Dieter [Zentralklinik Bad Berka, Department of Internal Medicine/Gastroenterology, Oncology and Endocrinology, Bad Berka (Germany)

2010-01-15

This bi-centric study aimed to determine the role of receptor PET/CT using {sup 68}Ga-DOTA-NOC in the detection of undiagnosed primary sites of neuroendocrine tumours (NETs) and to understand the molecular behaviour of the primarily undiagnosed tumours. Overall 59 patients (33 men and 26 women, age: 65 {+-} 9 years) with documented NET and unknown primary were enrolled. PET/CT was performed after injection of approximately 100 MBq (46-260 MBq) of {sup 68}Ga-DOTA-NOC. The maximum standardised uptake values (SUV{sub max}) were calculated and compared with SUV{sub max} in known pancreatic NET (pNET) and ileum/jejunum/duodenum (SI-NET). The results of PET/CT were also correlated with CT alone. In 35 of 59 patients (59%), {sup 68}Ga-DOTA-NOC PET/CT localised the site of the primary: ileum/jejunum (14), pancreas (16), rectum/colon (2), lungs (2) and paraganglioma (1). CT alone (on retrospective analyses) confirmed the findings in 12 of 59 patients (20%). The mean SUV{sub max} of identified previously unknown pNET and SI-NET were 18.6 {+-} 9.8 (range: 7.8-34.8) and 9.1 {+-} 6.0 (range: 4.2-27.8), respectively. SUV{sub max} in patients with previously known pNET and SI-NET were 26.1 {+-} 14.5 (range: 8.7-42.4) and 11.3 {+-} 3.7 (range: 5.6-17.9). The SUV{sub max} of the unknown pNET and SI-NET were significantly lower (p < 0.05) as compared to the ones with known primary tumour sites; 19% of the patients had high-grade and 81% low-grade NET. Based on {sup 68}Ga-DOTA-NOC receptor PET/CT, 6 of 59 patients were operated and the primary was removed (4 pancreatic, 1 ileal and 1 rectal tumour) resulting in a management change in approximately 10% of the patients. In the remaining 29 patients, because of the far advanced stage of the disease (due to distant metastases), the primary tumours were not operated. Additional histopathological sampling was available from one patient with bronchial carcinoid (through bronchoscopy). Our data indicate that {sup 68}Ga-DOTA-NOC PET/CT is

Estimating patterns in Spartina alterniflora belowground biomass within salt marshes

Science.gov (United States)

O'Connell, J. L.; Mishra, D. R.; Alber, M.; Byrd, K. B.

2017-12-01

Belowground biomass of marsh plants, such as Spartina alterniflora, help prevent marsh loss because they promote soil accretion, stabilize soils and add organic matter. However, site-wide estimates of belowground biomass are difficult to obtain because root:shoot ratios vary considerably both within species and across sites. We are working to develop a data fusion tool that can predict key characteristics of S. alterniflora, including belowground biomass and plant canopy N, based on satellite imagery. We used field observations from four salt marsh locations along the Georgia Coast, including one that is studied as part of the Georgia Coastal Ecosystems LTER project. From field and remote-sensing data, we developed a hybrid modeling approach to estimate % foliar N (a surrogate for plant assimilated nutrients). Partial Least squares (PLS) regression analysis of Landsat-8 spectral bands could predict variation in foliar N and belowground biomass, suggesting this public data source might be utilized for site-wide assessment of plant biophysical variables in salt marshes. Spectrally estimated foliar N and aboveground biomass were associated with belowground biomass and root:shoot ratio in S. alterniflora. This mirrors results from a previous study from the Sacramento-San Joaquin Delta, CA, on Scheonoplectus acutus, a marsh plant found in some tidal freshwater marshes. Therefore remote sensing may be a useful tool for measuring whole plant productivity among multiple coastal marsh species.

Above and belowground connections and species interactions: Controls over ecosystem fluxes

Energy Technology Data Exchange (ETDEWEB)

Trowbridge, Amy Marie [Montana State Univ., Bozeman, MT (United States); Phillips, Richard [Indiana Univ., Bloomington, IN (United States); Stoy, Paul Christopher [Montana State Univ., Bozeman, MT (United States)

2016-11-01

The ultimate goal of this work was to quantify soil and volatile organic compound fluxes as a function of tree species and associated mycorrhizal associations in an intact forest, but also to describe the physical and biological factors that control these emissions. The results of this research lay the foundation toward an improved mechanistic understanding of carbon pathways, fluxes, and ecosystem function, ultimately improving the representation of forest ecosystems in Earth System models. To this end, a multidisciplinary approach was necessary to fill a critical gap in our understanding of how soil and root processes may influence whole-ecosystem carbon-based volatile fluxes in the face of a rapidly changing climate. We developed a series of novel sampling protocols and coupled a variety of advanced analytical techniques, resulting in findings relevant across disciplines. Furthermore, we leveraged existing infrastructure, research sites, and datasets to design a low-cost exploratory project that links belowground processes, soil volatile emissions, and total ecosystem carbon budgets. Measurements from soil collars installed across a species/mycorrhizal gradient at the DOE-supported Moran Monroe State Forest Ameriflux tower site suggest that leaf litter is the primary source of belowground and forest floor volatile emissions, but the strength of this source is significantly affected not only by leaf litter type, but the strength of the soil as a sink. Results suggest that the strength of the sink is influenced by tree species-specific associated microbial communities that change throughout the season as a function of temperature, soil moisture, leaf litter inputs, and phenology. The magnitude of the observed volatile fluxes from the forest floor is small relative to total aboveground ecosystem flux, but the contribution of these emissions to volatile-mediated ecological interactions and soil processes (e.g. nitrification) varies substantially across the growing

HANPP Collection: Human Appropriation of Net Primary Productivity (HANPP) by Country and Product

Data.gov (United States)

National Aeronautics and Space Administration — The Human Appropriation of Net Primary Productivity (HANPP) by Country and Product portion of the HANPP Collection contains tabular data on carbon-equivalents of...

Estimation of livestock appropriation of net primary productivity in Texas Drylands

Science.gov (United States)

Robert Washington-Allen; Jody Fitzgerald; Stephanie Grounds; Faisar Jihadi; John Kretzschmar; Kathryn Ramirez; John Mitchell

2009-01-01

The ecological state of US Drylands is unknown. This research is developing procedures to determine the impact of the ecological footprint of grazing livestock on the productive capacity of US Drylands. A pilot geodatabase was developed for the state of Texas that includes 2002 data for county boundaries, net primary productivity (NPP) derived from the Moderate...

How drought severity constrains gross primary production(GPP) and its partitioning among carbon pools in a Quercus ilex coppice?

Science.gov (United States)

Rambal, S.; Lempereur, M.; Limousin, J. M.; Martin-StPaul, N. K.; Ourcival, J. M.; Rodríguez-Calcerrada, J.

2014-12-01

The partitioning of photosynthates toward biomass compartments plays a crucial role in the carbon (C) sink function of forests. Few studies have examined how carbon is allocated toward plant compartments in drought-prone forests. We analyzed the fate of gross primary production (GPP) in relation to yearly water deficit in an old evergreen Mediterranean Quercus ilex coppice severely affected by water limitations. Carbon fluxes between the ecosystem and the atmosphere were measured with an eddy covariance flux tower running continuously since 2001. Discrete measurements of litterfall, stem growth and fAPAR allowed us to derive annual productions of leaves, wood, flowers and acorns, and an isometric relationship between stem and belowground biomass has been used to estimate perennial belowground growth. By combining eddy covariance fluxes with annual net primary productions (NPP), we managed to close a C budget and derive values of autotrophic, heterotrophic respirations and carbon-use efficiency (CUE; the ratio between NPP and GPP). Average values of yearly net ecosystem production (NEP), GPP and Reco were 282, 1259 and 977 g C m-2. The corresponding aboveground net primary production (ANPP) components were 142.5, 26.4 and 69.6 g C m-2 for leaves, reproductive effort (flowers and fruits) and stems, respectively. NEP, GPP and Reco were affected by annual water deficit. Partitioning to the different plant compartments was also impacted by drought, with a hierarchy of responses going from the most affected - the stem growth - to the least affected - the leaf production. The average CUE was 0.40, which is well in the range for Mediterranean-type forest ecosystems. CUE tended to decrease less drastically in response to drought than GPP and NPP did, probably due to drought acclimation of autotrophic respiration. Overall, our results provide a baseline for modeling the inter-annual variations of carbon fluxes and allocation in this widespread Mediterranean ecosystem, and

Decreasing Net Primary Productivity in Response to Urbanization in Liaoning Province, China

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Tan Chen

2017-01-01

Full Text Available Regional ecosystems have been greatly affected by the rapid expansion of urban areas. In order to explore the impact of land use change on net primary productivity (NPP in rapidly developing cities during the current urbanization process, we quantified land use change in Liaoning province between 2000 and 2010 using net primary productivity as an indicator of ecosystem productivity and health. The Carnegie–Ames–Stanford Approach model was used to estimate NPP by region and land use. We used a unit circle-based evaluation model to quantify local urbanization effects on NPP around eight representative cities. The dominant land use types were farmland, woodland and urban, with urban rapidly replacing farmland. Mean annual NPP and total NPP decreased faster from 2005 to 2010 than from 2000 to 2005, reflecting increasing urbanization rates. The eastern, primarily woodland part of Liaoning province had the greatest reduction in NPP, while the western part, which was primarily farmland and grassland, had the lowest reduction.

Morchella tomentosa: a unique belowground structure and a new clade of morels

Science.gov (United States)

Franck O.P. Stefani; Serge Sokolski; Trish L. Wurtz; Yves Piché; Richard C. Hamelin; J. André Fortin; Jean A. Bérubé

2010-01-01

Mechanisms involved in post-fire morel fructification remain unclear. A new undescribed belowground vegetative structure of Marchella tomentosa in a burned boreal forest was investigated north of Fairbanks, Alaska. The name "radiscisclerotium" is proposed to define this peculiar and elaborate belowground vegetative structure of ...

First Assessment of Carbon Stock in the Belowground Biomass of Brazilian Mangroves

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DANIEL M.C. SANTOS

2017-08-01

Full Text Available ABSTRACT Studies on belowground roots biomass have increasingly reported the importance of the contribution of this compartment in carbon stock maintenance in mangrove forests. To date, there are no estimates of this contribution in Brazilian mangrove forests, although the country has the second largest area of mangroves worldwide. For this study, trenches dug in fringing forests in Guaratiba State Biological Reserve (Rio de Janeiro, Brazil were used to evaluate the contribution of the different classes of roots and the vertical stratification of carbon stock. The total carbon stock average in belowground roots biomass in these forests was 104.41 ± 20.73 tC.ha−1. From that, an average of 84.13 ± 21.34 tC.ha−1 corresponded to the carbon stock only in fine roots, which have diameters smaller than 5 mm and are responsible for over 80% of the total belowground biomass. Most of the belowground carbon stock is concentrated in the first 40 cm below the surface (about 70%. The root:shoot ratio in this study is 1.14. These estimates demonstrate that the belowground roots biomass significantly contributes, more than 50%, to the carbon stock in mangrove forests. And the mangrove root biomass can be greater than that of other Brazilian ecosystems.

Altered belowground carbon cycling following land use change to perennial bioenergy crops

Science.gov (United States)

Belowground carbon (C) dynamics of terrestrial ecosystems play an important role in the global C cycle and thereby in climate regulation, yet remain poorly understood. Globally, land use change is a major driver of changes in belowground C storage; in general, land clearing and tillage for agricult...

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

Science.gov (United States)

Yang, Yuanhe; Yang, Lucun; Zhou, Guoying

2016-01-01

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

Positive responses of belowground C dynamics to nitrogen enrichment in China.

Science.gov (United States)

Deng, Lei; Peng, Changhui; Zhu, Guangyu; Chen, Lei; Liu, Yulin; Shangguan, Zhouping

2018-03-01

Determining how nitrogen (N) impacts ecosystem carbon (C) cycling is critical to using C sequestration to offset anthropogenic CO 2 emissions. The N deposition rate in China is higher than the global average; however, many results of N enrichment experiments in China have not been included in global syntheses. In this study, we assembled a large dataset that comprised 124 published studies concerning N addition experiments, including 570 observations at 127 sites across China, to quantify the responses of belowground C dynamics to N enrichment in terrestrial ecosystems in China by a meta-analysis. The results showed that overall soil organic C, dissolved organic C (DOC) and soil microbial biomass C (MBC) increased by 1.8, 7.4, and 8.8%, respectively (Penrichment; belowground biomass and litter increased by 14.6 and 24.4%, respectively (Penrichment promoted C inputs into the soil mainly by increasing litter and belowground biomass inputs. Additionally, N enrichment increased C output by increasing soil respiration. Land use type and N addition level had different impacts on the soil C pool and on soil respiration. DOC, MBC, and litter exhibited more positive responses to N deposition in cooler and more arid regions than in other regions. The meta-analysis indicated that N enrichment had a positive impact on belowground C cycles in China. Climate played a greater role than did N deposition level in affecting processes of ecosystem C cycling. Moreover, belowground C cycle processes are determined by complicated interactions among land use type, N enrichment, and climate. Copyright © 2017 Elsevier B.V. All rights reserved.

Fire intensity impacts on post-fire temperate coniferous forest net primary productivity

Science.gov (United States)

Sparks, Aaron M.; Kolden, Crystal A.; Smith, Alistair M. S.; Boschetti, Luigi; Johnson, Daniel M.; Cochrane, Mark A.

2018-02-01

Fire is a dynamic ecological process in forests and impacts the carbon (C) cycle through direct combustion emissions, tree mortality, and by impairing the ability of surviving trees to sequester carbon. While studies on young trees have demonstrated that fire intensity is a determinant of post-fire net primary productivity, wildland fires on landscape to regional scales have largely been assumed to either cause tree mortality, or conversely, cause no physiological impact, ignoring the impacted but surviving trees. Our objective was to understand how fire intensity affects post-fire net primary productivity in conifer-dominated forested ecosystems on the spatial scale of large wildland fires. We examined the relationships between fire radiative power (FRP), its temporal integral (fire radiative energy - FRE), and net primary productivity (NPP) using 16 years of data from the MOderate Resolution Imaging Spectrometer (MODIS) for 15 large fires in western United States coniferous forests. The greatest NPP post-fire loss occurred 1 year post-fire and ranged from -67 to -312 g C m-2 yr-1 (-13 to -54 %) across all fires. Forests dominated by fire-resistant species (species that typically survive low-intensity fires) experienced the lowest relative NPP reductions compared to forests with less resistant species. Post-fire NPP in forests that were dominated by fire-susceptible species were not as sensitive to FRP or FRE, indicating that NPP in these forests may be reduced to similar levels regardless of fire intensity. Conversely, post-fire NPP in forests dominated by fire-resistant and mixed species decreased with increasing FRP or FRE. In some cases, this dose-response relationship persisted for more than a decade post-fire, highlighting a legacy effect of fire intensity on post-fire C dynamics in these forests.

Variance-based sensitivity analysis of BIOME-BGC for gross and net primary production

NARCIS (Netherlands)

Raj, R.; Hamm, N.A.S.; van der Tol, C.; Stein, A.

2014-01-01

Parameterization and calibration of a process-based simulator (PBS) is a major challenge when simulating gross and net primary production (GPP and NPP). The large number of parameters makes the calibration computationally expensive and is complicated by the dependence of several parameters on other

Belowground competition from overstory trees influences Douglas-fir sapling morphology in thinned stands

Science.gov (United States)

Warren D. Devine; Timothy B. Harrington

2009-01-01

We evaluated effects of belowground competition on morphology of naturally established coast Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) saplings in 60- to 80-year-old thinned Douglas-fir stands in southwestern Washington. We separately quantified belowground competition from overstory and understory sources...

Creating a regional MODIS satellite-driven net primary production dataset for european forests

NARCIS (Netherlands)

Neumann, Mathias; Moreno, Adam; Thurnher, Christopher; Mues, Volker; Härkönen, Sanna; Mura, Matteo; Bouriaud, Olivier; Lang, Mait; Cardellini, Giuseppe; Thivolle-Cazat, Alain; Bronisz, Karol; Merganic, Jan; Alberdi, Iciar; Astrup, Rasmus; Mohren, Frits; Zhao, Maosheng; Hasenauer, Hubert

2016-01-01

Net primary production (NPP) is an important ecological metric for studying forest ecosystems and their carbon sequestration, for assessing the potential supply of food or timber and quantifying the impacts of climate change on ecosystems. The global MODIS NPP dataset using the MOD17 algorithm

Comparison of modeling approaches for carbon partitioning: Impact on estimates of global net primary production and equilibrium biomass of woody vegetation from MODIS GPP

Science.gov (United States)

Ise, Takeshi; Litton, Creighton M.; Giardina, Christian P.; Ito, Akihiko

2010-12-01

Partitioning of gross primary production (GPP) to aboveground versus belowground, to growth versus respiration, and to short versus long-lived tissues exerts a strong influence on ecosystem structure and function, with potentially large implications for the global carbon budget. A recent meta-analysis of forest ecosystems suggests that carbon partitioning to leaves, stems, and roots varies consistently with GPP and that the ratio of net primary production (NPP) to GPP is conservative across environmental gradients. To examine influences of carbon partitioning schemes employed by global ecosystem models, we used this meta-analysis-based model and a satellite-based (MODIS) terrestrial GPP data set to estimate global woody NPP and equilibrium biomass, and then compared it to two process-based ecosystem models (Biome-BGC and VISIT) using the same GPP data set. We hypothesized that different carbon partitioning schemes would result in large differences in global estimates of woody NPP and equilibrium biomass. Woody NPP estimated by Biome-BGC and VISIT was 25% and 29% higher than the meta-analysis-based model for boreal forests, with smaller differences in temperate and tropics. Global equilibrium woody biomass, calculated from model-specific NPP estimates and a single set of tissue turnover rates, was 48 and 226 Pg C higher for Biome-BGC and VISIT compared to the meta-analysis-based model, reflecting differences in carbon partitioning to structural versus metabolically active tissues. In summary, we found that different carbon partitioning schemes resulted in large variations in estimates of global woody carbon flux and storage, indicating that stand-level controls on carbon partitioning are not yet accurately represented in ecosystem models.

Ecological linkages between aboveground and belowground biota

NARCIS (Netherlands)

Wardle, D.A.; Bardgett, R.D.; Klironomos, J.N.; Setälä, H.; Putten, van der W.H.; Wall, D.H.

2004-01-01

All terrestrial ecosystems consist of aboveground and belowground components that interact to influence community- and ecosystem-level processes and properties. Here we show how these components are closely interlinked at the community level, reinforced by a greater degree of specificity between

Stimulation of the Salicylic Acid Pathway Aboveground Recruits Entomopathogenic Nematodes Belowground.

Directory of Open Access Journals (Sweden)

Camila Cramer Filgueiras

Full Text Available Plant defense pathways play a critical role in mediating tritrophic interactions between plants, herbivores, and natural enemies. While the impact of plant defense pathway stimulation on natural enemies has been extensively explored aboveground, belowground ramifications of plant defense pathway stimulation are equally important in regulating subterranean pests and still require more attention. Here we investigate the effect of aboveground stimulation of the salicylic acid pathway through foliar application of the elicitor methyl salicylate on belowground recruitment of the entomopathogenic nematode, Steinernema diaprepesi. Also, we implicate a specific root-derived volatile that attracts S. diaprepesi belowground following aboveground plant stimulation by an elicitor. In four-choice olfactometer assays, citrus plants treated with foliar applications of methyl salicylate recruited S. diaprepesi in the absence of weevil feeding as compared with negative controls. Additionally, analysis of root volatile profiles of citrus plants receiving foliar application of methyl salicylate revealed production of d-limonene, which was absent in negative controls. The entomopathogenic nematode S. diaprepesi was recruited to d-limonene in two-choice olfactometer trials. These results reinforce the critical role of plant defense pathways in mediating tritrophic interactions, suggest a broad role for plant defense pathway signaling belowground, and hint at sophisticated plant responses to pest complexes.

Stimulation of the Salicylic Acid Pathway Aboveground Recruits Entomopathogenic Nematodes Belowground

Science.gov (United States)

Filgueiras, Camila Cramer; Willett, Denis S.; Junior, Alcides Moino; Pareja, Martin; Borai, Fahiem El; Dickson, Donald W.; Stelinski, Lukasz L.; Duncan, Larry W.

2016-01-01

Plant defense pathways play a critical role in mediating tritrophic interactions between plants, herbivores, and natural enemies. While the impact of plant defense pathway stimulation on natural enemies has been extensively explored aboveground, belowground ramifications of plant defense pathway stimulation are equally important in regulating subterranean pests and still require more attention. Here we investigate the effect of aboveground stimulation of the salicylic acid pathway through foliar application of the elicitor methyl salicylate on belowground recruitment of the entomopathogenic nematode, Steinernema diaprepesi. Also, we implicate a specific root-derived volatile that attracts S. diaprepesi belowground following aboveground plant stimulation by an elicitor. In four-choice olfactometer assays, citrus plants treated with foliar applications of methyl salicylate recruited S. diaprepesi in the absence of weevil feeding as compared with negative controls. Additionally, analysis of root volatile profiles of citrus plants receiving foliar application of methyl salicylate revealed production of d-limonene, which was absent in negative controls. The entomopathogenic nematode S. diaprepesi was recruited to d-limonene in two-choice olfactometer trials. These results reinforce the critical role of plant defense pathways in mediating tritrophic interactions, suggest a broad role for plant defense pathway signaling belowground, and hint at sophisticated plant responses to pest complexes. PMID:27136916

Similar below-ground carbon cycling dynamics but contrasting modes of nitrogen cycling between arbuscular mycorrhizal and ectomycorrhizal forests.

Science.gov (United States)

Lin, Guigang; McCormack, M Luke; Ma, Chengen; Guo, Dali

2017-02-01

Compared with ectomycorrhizal (ECM) forests, arbuscular mycorrhizal (AM) forests are hypothesized to have higher carbon (C) cycling rates and a more open nitrogen (N) cycle. To test this hypothesis, we synthesized 645 observations, including 22 variables related to below-ground C and N dynamics from 100 sites, where AM and ECM forests co-occurred at the same site. Leaf litter quality was lower in ECM than in AM trees, leading to greater forest floor C stocks in ECM forests. By contrast, AM forests had significantly higher mineral soil C concentrations, and this result was strongly mediated by plant traits and climate. No significant differences were found between AM and ECM forests in C fluxes and labile C concentrations. Furthermore, inorganic N concentrations, net N mineralization and nitrification rates were all higher in AM than in ECM forests, indicating 'mineral' N economy in AM but 'organic' N economy in ECM trees. AM and ECM forests show systematic differences in mineral vs organic N cycling, and thus mycorrhizal type may be useful in predicting how different tree species respond to multiple environmental change factors. By contrast, mycorrhizal type alone cannot reliably predict below-ground C dynamics without considering plant traits and climate. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Plant life history and above–belowground interactions

NARCIS (Netherlands)

Deyn, de Gerlinde

2017-01-01

The importance of above–belowground interactions for plant growth and community dynamics became clear in the last decades, whereas the numerous studies on plant life history improved our knowledge on eco-evolutionary dynamics. However, surprisingly few studies have linked both research fields

Variations of Terrestrial Net Primary Productivity in East Asia

Directory of Open Access Journals (Sweden)

Fangmin Zhang

2012-01-01

Full Text Available Due to the heterogeneity and complexity of terrestrial ecosystems of East Asia, a better understanding of relationships between climate change and net primary productivity (NPP distribution is important to predict future carbon dynamics. The objective of this study is to analyze the temporal-spatial patterns of NPP in East Asia (10°S - 55°N, 60 - 155°E from 1982 to 2006 using the process-based Boreal Ecosystem Productivity Simulator (BEPS model. Prior to the regional simulation, the annual simulated NPP was validated using field observed NPP demonstrating the ability of BEPS to simulate NPP in different ecosystems of East Asia.

Large grazers modify effects of aboveground-belowground interactions on small-scale plant community composition

NARCIS (Netherlands)

Veen, G. F. (Ciska); Geuverink, Elzemiek; Olff, Han; Schmid, Bernhard

Aboveground and belowground organisms influence plant community composition by local interactions, and their scale of impact may vary from millimeters belowground to kilometers aboveground. However, it still poorly understood how large grazers that select their forage on large spatial scales

Large grazers modify effects of aboveground–belowground interactions on small-scale plant community composition

NARCIS (Netherlands)

Veen, G.F.; Geuverink, E.; Olff, H.

2012-01-01

Aboveground and belowground organisms influence plant community composition by local interactions, and their scale of impact may vary from millimeters belowground to kilometers aboveground. However, it still poorly understood how large grazers that select their forage on large spatial scales

The roots of defense: plant resistance and tolerance to belowground herbivory.

Directory of Open Access Journals (Sweden)

Sean M Watts

2011-04-01

Full Text Available There is conclusive evidence that there are fitness costs of plant defense and that herbivores can drive selection for defense. However, most work has focused on above-ground interactions, even though belowground herbivory may have greater impacts on individual plants than above-ground herbivory. Given the role of belowground plant structures in resource acquisition and storage, research on belowground herbivores has much to contribute to theories on the evolution of plant defense. Pocket gophers (Geomyidae provide an excellent opportunity to study root herbivory. These subterranean rodents spend their entire lives belowground and specialize on consuming belowground plant parts.We compared the root defenses of native forbs from mainland populations (with a history of gopher herbivory to island populations (free from gophers for up to 500,000 years. Defense includes both resistance against herbivores and tolerance of herbivore damage. We used three approaches to compare these traits in island and mainland populations of two native California forbs: 1 Eschscholzia californica populations were assayed to compare alkaloid deterrents, 2 captive gophers were used to test the palatability of E. californica roots and 3 simulated root herbivory assessed tolerance to root damage in Deinandra fasciculata and E. californica. Mainland forms of E. californica contained 2.5 times greater concentration of alkaloids and were less palatable to gophers than island forms. Mainland forms of D. fasciculata and, to a lesser extent, E. californica were also more tolerant of root damage than island conspecifics. Interestingly, undamaged island individuals of D. fasciculata produced significantly more fruit than either damaged or undamaged mainland individuals.These results suggest that mainland plants are effective at deterring and tolerating pocket gopher herbivory. Results also suggest that both forms of defense are costly to fitness and thus reduced in the absence of

Linking aboveground and belowground inducible plant resistance

NARCIS (Netherlands)

Bezemer, T.M.

2009-01-01

Induced resistance of plants against pests and diseases via plant defense responses is well documented and can occur aboveground, in the leaves, and belowground in the roots. A number of recent studies have shown that soil-borne pests can also induce plant resistance aboveground and vice versa.

Soil fertility shapes belowground food webs across a regional climate gradient.

Science.gov (United States)

Laliberté, Etienne; Kardol, Paul; Didham, Raphael K; Teste, François P; Turner, Benjamin L; Wardle, David A

2017-10-01

Changes in soil fertility during pedogenesis affect the quantity and quality of resources entering the belowground subsystem. Climate governs pedogenesis, yet how climate modulates responses of soil food webs to soil ageing remains unexplored because of the paucity of appropriate model systems. We characterised soil food webs along each of four retrogressive soil chronosequences situated across a strong regional climate gradient to show that belowground communities are predominantly shaped by changes in fertility rather than climate. Basal consumers showed hump-shaped responses to soil ageing, which were propagated to higher-order consumers. There was a shift in dominance from bacterial to fungal energy channels with increasing soil age, while the root energy channel was most important in intermediate-aged soils. Our study highlights the overarching importance of soil fertility in regulating soil food webs, and indicates that belowground food webs will respond more strongly to shifts in soil resources than climate change. © 2017 John Wiley & Sons Ltd/CNRS.

Relationships between net primary productivity and forest stand age in U.S. forests

Science.gov (United States)

Liming He; Jing M. Chen; Yude Pan; Richard Birdsey; Jens. Kattge

2012-01-01

Net primary productivity (NPP) is a key flux in the terrestrial ecosystem carbon balance, as it summarizes the autotrophic input into the system. Forest NPP varies predictably with stand age, and quantitative information on the NPP-age relationship for different regions and forest types is therefore fundamentally important for forest carbon cycle modeling. We used four...

Net ecosystem CO2 exchange of a primary tropical peat swamp forest in Sarawak, Malaysia

Science.gov (United States)

Tang Che Ing, A.; Stoy, P. C.; Melling, L.

2014-12-01

Tropical peat swamp forests are widely recognized as one of the world's most efficient ecosystems for the sequestration and storage of carbon through both their aboveground biomass and underlying thick deposits of peat. As the peat characteristics exhibit high spatial and temporal variability as well as the structural and functional complexity of forests, tropical peat ecosystems can act naturally as both carbon sinks and sources over their life cycles. Nonetheless, few reports of studies on the ecosystem-scale CO2 exchange of tropical peat swamp forests are available to-date and their present roles in the global carbon cycle remain uncertain. To quantify CO2 exchange and unravel the prevailing factors and potential underlying mechanism regulating net CO2 fluxes, an eddy covariance tower was erected in a tropical peat swamp forest in Sarawak, Malaysia. We observed that the diurnal and seasonal patterns of net ecosystem CO2 exchange (NEE) and its components (gross primary productivity (GPP) and ecosystem respiration (RE)) varied between seasons and years. Rates of NEE declined in the wet season relative to the dry season. Conversely, both the gross primary productivity (GPP) and ecosystem respiration (RE) were found to be higher during the wet season than the dry season, in which GPP was strongly negatively correlated with NEE. The average annual NEE was 385 ± 74 g C m-2 yr-1, indicating the primary peat swamp forest functioned as net source of CO2 to the atmosphere over the observation period.

Links between plant litter chemistry, species diversity, and below-ground ecosystem function.

Science.gov (United States)

Meier, Courtney L; Bowman, William D

2008-12-16

Decomposition is a critical source of plant nutrients, and drives the largest flux of terrestrial C to the atmosphere. Decomposing soil organic matter typically contains litter from multiple plant species, yet we lack a mechanistic understanding of how species diversity influences decomposition processes. Here, we show that soil C and N cycling during decomposition are controlled by the composition and diversity of chemical compounds within plant litter mixtures, rather than by simple metrics of plant species diversity. We amended native soils with litter mixtures containing up to 4 alpine plant species, and we used 9 litter chemical traits to evaluate the chemical composition (i.e., the identity and quantity of compounds) and chemical diversity of the litter mixtures. The chemical composition of the litter mixtures was the strongest predictor of soil respiration, net N mineralization, and microbial biomass N. Soil respiration and net N mineralization rates were also significantly correlated with the chemical diversity of the litter mixtures. In contrast, soil C and N cycling rates were poorly correlated with plant species richness, and there was no relationship between species richness and the chemical diversity of the litter mixtures. These results indicate that the composition and diversity of chemical compounds in litter are potentially important functional traits affecting decomposition, and simple metrics like plant species richness may fail to capture variation in these traits. Litter chemical traits therefore provide a mechanistic link between organisms, species diversity, and key components of below-ground ecosystem function.

Effects of nitrogen additions on above- and belowground carbon dynamics in two tropical forests

Energy Technology Data Exchange (ETDEWEB)

Cusack, D.; Silver, W.L.; Torn, M.S.; McDowell, W.H.

2011-04-15

Anthropogenic nitrogen (N) deposition is increasing rapidly in tropical regions, adding N to ecosystems that often have high background N availability. Tropical forests play an important role in the global carbon (C) cycle, yet the effects of N deposition on C cycling in these ecosystems are poorly understood. We used a field N-fertilization experiment in lower and upper elevation tropical rain forests in Puerto Rico to explore the responses of above- and belowground C pools to N addition. As expected, tree stem growth and litterfall productivity did not respond to N fertilization in either of these Nrich forests, indicating a lack of N limitation to net primary productivity (NPP). In contrast, soil C concentrations increased significantly with N fertilization in both forests, leading to larger C stocks in fertilized plots. However, different soil C pools responded to N fertilization differently. Labile (low density) soil C fractions and live fine roots declined with fertilization, while mineral-associated soil C increased in both forests. Decreased soil CO2 fluxes in fertilized plots were correlated with smaller labile soil C pools in the lower elevation forest (R2 = 0.65, p\\0.05), and with lower live fine root biomass in the upper elevation forest (R2 = 0.90, p\\0.05). Our results indicate that soil C storage is sensitive to N deposition in tropical forests, even where plant productivity is not N-limited. The mineral-associated soil C pool has the potential to respond relatively quickly to N additions, and can drive increases in bulk soil C stocks in tropical forests.

POLICY FRAMEWORK FOR UTILIZATION AND CONSERVATION OF BELOW-GROUND BIODIVERSITY IN KENYA

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Celline Achieng

2009-10-01

Full Text Available The reasons for the lack of inclusion of below-ground biodiversity in the Kenyan policy and legal framework were sought. Gaps were identified in the relevant sectoral policies and laws in regard to the domestication of the Convention on Biological Diversity (CBD. Below -ground biodiversity had no specific schedule in any of the sectoral laws. Most sectoral laws were particular about the larger biodiversity and soils but had no mention of below-ground biodiversity. Material Transfer Agreements and Material Acquisition Agreements that are regarded as tools of domestication of the CBD to guide transfers, exchanges and acquisition of soil organisms lacked a regulating policy. The lack of regulating policy could be attributed to the delay in approval of draft regulations by the Ministry of Environment while the lack of inclusion of below-ground biodiversity in Kenya’s legal and policy framework could be as a result of lack of awareness and appreciation among stakeholders.

Use of belowground growing degree days to predict rooting of dormant hardwood cuttings of Populus

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R.S., Jr. Zalesny; E.O. Bauer; D.E. Riemenschneider

2004-01-01

Planting Populus cuttings based on calendar days neglects soil temperature extremes and does not promote rooting based on specific genotypes. Our objectives were to: 1) test the biological efficacy of a thermal index based on belowground growing degree days (GDD) across the growing period, 2) test for interactions between belowground GDD and clones,...

Plant genetic variation mediates an indirect ecological effect between belowground earthworms and aboveground aphids.

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Singh, Akanksha; Braun, Julia; Decker, Emilia; Hans, Sarah; Wagner, Agnes; Weisser, Wolfgang W; Zytynska, Sharon E

2014-10-21

Interactions between aboveground and belowground terrestrial communities are often mediated by plants, with soil organisms interacting via the roots and aboveground organisms via the shoots and leaves. Many studies now show that plant genetics can drive changes in the structure of both above and belowground communities; however, the role of plant genetic variation in mediating aboveground-belowground interactions is still unclear. We used an earthworm-plant-aphid model system with two aphid species (Aphis fabae and Acyrthosiphon pisum) to test the effect of host-plant (Vicia faba) genetic variation on the indirect interaction between the belowground earthworms (Eisenia veneta) on the aboveground aphid populations. Our data shows that host-plant variety mediated an indirect ecological effect of earthworms on generalist black bean aphids (A. fabae), with earthworms increasing aphid growth rate in three plant varieties but decreasing it in another variety. We found no effect of earthworms on the second aphid species, the pea aphid (A. pisum), and no effect of competition between the aphid species. Plant biomass was increased when earthworms were present, and decreased when A. pisum was feeding on the plant (mediated by plant variety). Although A. fabae aphids were influenced by the plants and worms, they did not, in turn, alter plant biomass. Previous work has shown inconsistent effects of earthworms on aphids, but we suggest these differences could be explained by plant genetic variation and variation among aphid species. This study demonstrates that the outcome of belowground-aboveground interactions can be mediated by genetic variation in the host-plant, but depends on the identity of the species involved.

The Effect of a Short-term Glucose Deprivation on Neuron Net Functioning of Hippocampus Primary Culture on a Multi-electrode Matrix

OpenAIRE

Vedunova M.V.; Korotchenko S.A.; Balashova A.N.; Isakova A.O.; Khaspekov L.G.; Kazantsev V.B.; Mukhina I.V.

2011-01-01

There has been studied the effect of a short-term glucose deprivation on neuron net functioning of hippocampus primary culture developing within 32 days on a multi-electrode matrix MED64 (Alpha MED Sciences Company, Japan) in an early and remote periods after deprivation. A short-term glucose deprivation (20 min) has been shown to result in the increase of electrobiological activity of neuron net of hippocampus primary culture, with the cascade of metabolic reactions being activated leading t...

Aboveground vs. Belowground Carbon Stocks in African Tropical Lowland Rainforest: Drivers and Implications.

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Sebastian Doetterl

Full Text Available African tropical rainforests are one of the most important hotspots to look for changes in the upcoming decades when it comes to C storage and release. The focus of studying C dynamics in these systems lies traditionally on living aboveground biomass. Belowground soil organic carbon stocks have received little attention and estimates of the size, controls and distribution of soil organic carbon stocks are highly uncertain. In our study on lowland rainforest in the central Congo basin, we combine both an assessment of the aboveground C stock with an assessment of the belowground C stock and analyze the latter in terms of functional pools and controlling factors.Our study shows that despite similar vegetation, soil and climatic conditions, soil organic carbon stocks in an area with greater tree height (= larger aboveground carbon stock were only half compared to an area with lower tree height (= smaller aboveground carbon stock. This suggests that substantial variability in the aboveground vs. belowground C allocation strategy and/or C turnover in two similar tropical forest systems can lead to significant differences in total soil organic C content and C fractions with important consequences for the assessment of the total C stock of the system.We suggest nutrient limitation, especially potassium, as the driver for aboveground versus belowground C allocation. However, other drivers such as C turnover, tree functional traits or demographic considerations cannot be excluded. We argue that large and unaccounted variability in C stocks is to be expected in African tropical rain-forests. Currently, these differences in aboveground and belowground C stocks are not adequately verified and implemented mechanistically into Earth System Models. This will, hence, introduce additional uncertainty to models and predictions of the response of C storage of the Congo basin forest to climate change and its contribution to the terrestrial C budget.

Aboveground vs. Belowground Carbon Stocks in African Tropical Lowland Rainforest: Drivers and Implications.

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Doetterl, Sebastian; Kearsley, Elizabeth; Bauters, Marijn; Hufkens, Koen; Lisingo, Janvier; Baert, Geert; Verbeeck, Hans; Boeckx, Pascal

2015-01-01

African tropical rainforests are one of the most important hotspots to look for changes in the upcoming decades when it comes to C storage and release. The focus of studying C dynamics in these systems lies traditionally on living aboveground biomass. Belowground soil organic carbon stocks have received little attention and estimates of the size, controls and distribution of soil organic carbon stocks are highly uncertain. In our study on lowland rainforest in the central Congo basin, we combine both an assessment of the aboveground C stock with an assessment of the belowground C stock and analyze the latter in terms of functional pools and controlling factors. Our study shows that despite similar vegetation, soil and climatic conditions, soil organic carbon stocks in an area with greater tree height (= larger aboveground carbon stock) were only half compared to an area with lower tree height (= smaller aboveground carbon stock). This suggests that substantial variability in the aboveground vs. belowground C allocation strategy and/or C turnover in two similar tropical forest systems can lead to significant differences in total soil organic C content and C fractions with important consequences for the assessment of the total C stock of the system. We suggest nutrient limitation, especially potassium, as the driver for aboveground versus belowground C allocation. However, other drivers such as C turnover, tree functional traits or demographic considerations cannot be excluded. We argue that large and unaccounted variability in C stocks is to be expected in African tropical rain-forests. Currently, these differences in aboveground and belowground C stocks are not adequately verified and implemented mechanistically into Earth System Models. This will, hence, introduce additional uncertainty to models and predictions of the response of C storage of the Congo basin forest to climate change and its contribution to the terrestrial C budget.

Estimating climate change effects on net primary production of rangelands in the United States

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Matthew C. Reeves; Adam L. Moreno; Karen E. Bagne; Steven W. Running

2014-01-01

The potential effects of climate change on net primary productivity (NPP) of U.S. rangelands were evaluated using estimated climate regimes from the A1B, A2 and B2 global change scenarios imposed on the biogeochemical cycling model, Biome-BGC from 2001 to 2100. Temperature, precipitation, vapor pressure deficit, day length, solar radiation, CO2 enrichment and nitrogen...

Belowground Competition Directs Spatial Patterns of Seedling Growth in Boreal Pine Forests in Fennoscandia

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E. Petter Axelsson

2014-09-01

Full Text Available Aboveground competition is often argued to be the main process determining patterns of natural forest regeneration. However, the theory of multiple resource limitation suggests that seedling performance also depends on belowground competition and, thus, that their relative influence is of fundamental importance. Two approaches were used to address the relative importance of above- and below-ground competition on regeneration in a nutrient-poor pine (Pinus sylvestris boreal forest. Firstly, seedling establishment beneath trees stem-girdled 12 years ago show that a substantial proportion of the seedlings were established within two years after girdling, which corresponds to a time when nutrient uptake by tree roots was severely reduced without disrupting water transport to the tree canopy, which consequently was maintained. The establishment during these two years also corresponds to abundances high enough for normal stand replacement. Secondly, surveys of regeneration within forest gaps showed that surrounding forests depressed seedlings, so that satisfactory growth occurred only more than 5 m from forest edges and that higher solar radiation in south facing edges was not enough to mediate these effects. We conclude that disruption of belowground competitive interactions mediates regeneration and, thus, that belowground competition has a strong limiting influence on seedling establishment in these forests.

Incentivizing primary care providers to innovate: building medical homes in the post-Katrina New Orleans safety net.

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Rittenhouse, Diane R; Schmidt, Laura A; Wu, Kevin J; Wiley, James

2014-02-01

To evaluate safety-net clinics' responses to a novel community-wide Patient-Centered Medical Home (PCMH) financial incentive program in post-Katrina New Orleans. Between June 2008 and June 2010, we studied 50 primary care clinics in New Orleans receiving federal funds to expand services and improve care delivery. Multiwave, longitudinal, observational study of a local safety-net primary care system. Clinic-level data from a semiannual survey of clinic leaders (89.3 percent response rate), augmented by administrative records. Overall, 62 percent of the clinics responded to financial incentives by achieving PCMH recognition from the National Committee on Quality Assurance (NCQA). Higher patient volume, higher baseline PCMH scores, and type of ownership were significant predictors of achieving NCQA recognition. The steepest increase in adoption of PCMH processes occurred among clinics achieving the highest, Level 3, NCQA recognition. Following NCQA recognition, 88.9 percent stabilized or increased their use of PCMH processes, although several specific PCMH processes had very low rates of adoption overall. Findings demonstrate that widespread PCMH implementation is possible in a safety-net environment when external financial incentives are aligned with the goal of practice innovation. © Health Research and Educational Trust.

Creating a Regional MODIS Satellite-Driven Net Primary Production Dataset for European Forests

OpenAIRE

Neumann, Mathias; Moreno, Adam; Thurnher, Christopher; Mues, Volker; Härkönen, Sanna; Mura, Matteo; Bouriaud, Olivier; Lang, Mait; Cardellini, Giuseppe; Thivolle-Cazat, Alain; Bronisz, Karol; Merganic, Jan; Alberdi, Iciar; Astrup, Rasmus; Mohren, Frits

2016-01-01

Net primary production (NPP) is an important ecological metric for studying forest ecosystems and their carbon sequestration, for assessing the potential supply of food or timber and quantifying the impacts of climate change on ecosystems. The global MODIS NPP dataset using the MOD17 algorithm provides valuable information for monitoring NPP at 1-km resolution. Since coarse-resolution global climate data are used, the global dataset may contain uncertainties for Europe. We used a 1-km daily g...

netCare, a new collaborative primary health care service based in Swiss community pharmacies.

Science.gov (United States)

Erni, Pina; von Overbeck, Jan; Reich, Oliver; Ruggli, Martine

2016-01-01

The Swiss Pharmacists Association has launched a new collaborative project, netCare. Community pharmacists provide a standard form with structured triage based on decision trees and document findings. As a backup, they can collaborate with physicians via video consultation. The aim of the study was to evaluate the impact of this service on the Swiss health care system. All pharmacists offering netCare completed two training courses, a course covering the most common medical conditions observed in primary health care and a specific course on all of the decision trees. The pharmacists were free to decide whether they would provide the usual care or offer netCare triage. The patient was also free to accept or refuse netCare. Pharmacists reported the type of ailment, procedure of the consultation, treatment, patient information and outcomes of the follow-up call on a standardized form submitted to the study center. Pharmacists from 162 pharmacies performed 4118 triages over a period of 21 months. A backup consultation was needed for 17% of the cases. In follow-up calls, 84% of the patients who were seen only by pharmacists reported complete relief or symptom reduction. netCare is a low-threshold service by which pharmacists can manage common medical conditions with physician backup, if needed. This study showed that a pharmacist could resolve a large proportion of the cases. However, to be efficient and sustainable, this service must be fully integrated into the health care system. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of precipitation changes on aboveground net primary production and soil respiration in a switchgrass field

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This study attempted to test whether switchgrass aboveground net primary production (ANPP) responds to precipitation (PPT) changes in a double asymmetry pattern as framed by Knapp et al. (2016), and whether it is held true for other ecosystem processes such as soil respiration (SR). Data were colle...

Assessing the impact of urbanization on regional net primary productivity in Jiangyin County, China.

Science.gov (United States)

Xu, C; Liu, M; An, S; Chen, J M; Yan, P

2007-11-01

Urbanization is one of the most important aspects of global change. The process of urbanization has a significant impact on the terrestrial ecosystem carbon cycle. The Yangtze Delta region has one of the highest rates of urbanization in China. In this study, carried out in Jiangyin County as a representative region within the Yangtze Delta, land use and land cover changes were estimated using Landsat TM and ETM+ imagery. With these satellite data and the BEPS process model (Boreal Ecosystem Productivity Simulator), the impacts of urbanization on regional net primary productivity (NPP) and annual net primary production were assessed for 1991 and 2002. Landsat-based land cover maps in 1991 and 2002 showed that urban development encroached large areas of cropland and forest. Expansion of residential areas and reduction of vegetated areas were the major forms of land transformation in Jiangyin County during this period. Mean NPP of the total area decreased from 818 to 699 gCm(-2)yr(-1) during the period of 1991 to 2002. NPP of cropland was only reduced by 2.7% while forest NPP was reduced by 9.3%. Regional annual primary production decreased from 808 GgC in 1991 to 691 GgC in 2002, a reduction of 14.5%. Land cover changes reduced regional NPP directly, and the increasing intensity and frequency of human-induced disturbance in the urbanized areas could be the main reason for the decrease in forest NPP.

Nitrogen fertilization decouples roots and microbes: Reductions in belowground carbon allocation limit microbial activity

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Carrara, J.; Walter, C. A.; Govindarajulu, R.; Hawkins, J.; Brzostek, E. R.

2017-12-01

Nitrogen (N) deposition has enhanced the ability of trees to capture atmospheric carbon (C). The effect of elevated N on belowground C cycling, however, is variable and response mechanisms are largely unknown. Recent research has highlighted distinct differences between ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) trees in the strength of root-microbial interactions. In particular, ECM trees send more C to rhizosphere microbes to stimulate enzyme activity and nutrient mobilization than AM trees, which primarily rely on saprotrophic microbes to mobilize N. As such, we hypothesized that N fertilization would weaken root-microbial interactions and soil decomposition in ECM stands more than in AM stands. To test this hypothesis, we measured root-microbial interactions in ECM and AM plots in two long-term N fertilization studies, the Fernow Experimental Forest, WV and Bear Brook Watershed, ME. We found that N fertilization led to declines in plant C allocation belowground to fine root biomass, branching, and root exudation in ECM stands to a greater extent than in AM stands. As ECM roots are tightly coupled to the soil microbiome through energy and nutrient exchange, reductions in belowground C allocation were mirrored by shifts in microbial community composition and reductions in fungal gene expression. These shifts were accompanied by larger reductions in fungal-derived lignolytic and hydrolytic enzyme activity in ECM stands than in AM stands. In contrast, as the AM soil microbiome is less reliant on trees for C and are more adapted to high inorganic nutrient environments, the soil metagenome and transcriptome were more resilient to decreases in belowground C allocation. Collectively, our results indicate the N fertilization decoupled root-microbial interactions by reducing belowground carbon allocation in ECM stands. Thus, N fertilization may reduce soil turnover and increase soil C storage to a greater extent in forests dominated by ECM than AM trees.

Effects of Soil Texture on Belowground Carbon and Nutrient Storage in a Lowland Amazonian Forest Ecosystem.

Science.gov (United States)

Whendee L. Silver; Jason Neff; Megan McGroddy; Ed Veldkamp; Michael Keller; Raimundo Cosme

2000-01-01

Soil texture plays a key role in belowground C storage in forest ecosystems and strongly influences nutrient availability and retention, particularly in highly weathered soils. We used field data and the Century ecosystem model to explore the role of soil texture in belowground C storage, nutrient pool sizes, and N fluxes in highly weathered soils in an Amazonian...

Marsh Soil Responses to Nutrients: Belowground Structural and Organic Properties.

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Coastal marsh responses to nutrient enrichment apparently depend upon soil matrix and whether the system is primarily biogenic or minerogenic. Deteriorating organic rich marshes (Jamaica Bay, NY) receiving wastewater effluent had lower belowground biomass, organic matter, and soi...

Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests

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McIntosh, Anne C. S.; Macdonald, S. Ellen; Quideau, Sylvie A.

2016-01-01

Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta Forests.

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Anne C S McIntosh

Full Text Available Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs and multiple carbon-source substrate-induced respiration (MSIR of the forest floor microbial community environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis showed that two above-ground (mean tree diameter, litter cover and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs properties were associated with variation in understory plant community composition. These results provide

Understory Plant Community Composition Is Associated with Fine-Scale Above- and Below-Ground Resource Heterogeneity in Mature Lodgepole Pine (Pinus contorta) Forests.

Science.gov (United States)

McIntosh, Anne C S; Macdonald, S Ellen; Quideau, Sylvie A

2016-01-01

Understory plant communities play critical ecological roles in forest ecosystems. Both above- and below-ground ecosystem properties and processes influence these communities but relatively little is known about such effects at fine (i.e., one to several meters within-stand) scales, particularly for forests in which the canopy is dominated by a single species. An improved understanding of these effects is critical for understanding how understory biodiversity is regulated in such forests and for anticipating impacts of changing disturbance regimes. Our primary objective was to examine the patterns of fine-scale variation in understory plant communities and their relationships to above- and below-ground resource and environmental heterogeneity within mature lodgepole pine forests. We assessed composition and diversity of understory vegetation in relation to heterogeneity of both the above-ground (canopy tree density, canopy and tall shrub basal area and cover, downed wood biomass, litter cover) and below-ground (soil nutrient availability, decomposition, forest floor thickness, pH, and phospholipid fatty acids (PLFAs) and multiple carbon-source substrate-induced respiration (MSIR) of the forest floor microbial community) environment. There was notable variation in fine-scale plant community composition; cluster and indicator species analyses of the 24 most commonly occurring understory species distinguished four assemblages, one for which a pioneer forb species had the highest cover levels, and three others that were characterized by different bryophyte species having the highest cover. Constrained ordination (distance-based redundancy analysis) showed that two above-ground (mean tree diameter, litter cover) and eight below-ground (forest floor pH, plant available boron, microbial community composition and function as indicated by MSIR and PLFAs) properties were associated with variation in understory plant community composition. These results provide novel insights

Effects of elevated temperature and CO2 on aboveground-belowground systems: a case study with plants, their mutualistic bacteria and root / shoot herbivores

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James Michael William Ryalls

2013-11-01

Full Text Available Interactions between above- and belowground herbivores have been prominent in the field of aboveground-belowground ecology from the outset, although little is known about how climate change affects these organisms when they share the same plant. Additionally, the interactive effects of multiple factors associated with climate change such as elevated temperature (eT and elevated atmospheric carbon dioxide (eCO2 are untested. We investigated how eT and eCO2 affected larval development of the lucerne weevil (Sitona discoideus and colonisation by the pea aphid (Acyrthosiphon pisum, on three cultivars of a common host plant, lucerne (Medicago sativa. Sitona discoideus larvae feed on root nodules housing N2-fixing rhizobial bacteria, allowing us to test the effects of eT and eCO2 on three trophic levels. Moreover, we assessed the influence of these factors on plant growth. eT increased plant growth rate initially (6, 8 and 10 weeks after sowing, with cultivar ‘Sequel’ achieving the greatest height. Inoculation with aphids, however, reduced plant growth at week 14. eT severely reduced root nodulation by 43%, whereas eCO2 promoted nodulation by 56%, but only at ambient temperatures. Weevil presence increased net root biomass and nodulation, by 31 and 45%, respectively, showing an overcompensatory plant growth response. Effects of eT and eCO2 on root nodulation were mirrored by weevil larval development; eT and eCO2 reduced and increased larval development, respectively. Contrary to expectations, aphid colonisation was unaffected by eT or eCO2, but there was a near-significant 10% reduction in colonisation rates on plants with weevils present belowground. The contrasting effects of eT and eCO2 on weevils potentially occurred through changes in root nodulation patterns.

Improved estimates of net primary productivity from MODIS satellite data at regional and local scales

Science.gov (United States)

Yude Pan; Richard Birdsey; John Hom; Kevin McCullough; Kenneth Clark

2006-01-01

We compared estimates of net primary production (NPP) from the MODIS satellite with estimates from a forest ecosystem process model (PnET-CN) and forest inventory and analysis (FIA) data for forest types of the mid-Atlantic region of the United States. The regional means were similar for the three methods and for the dominant oak? hickory forests in the region. However...

Exploring Global Patterns in Human Appropriation of Net Primary Production Using Earth Observation Satellites and Statistical Data

Science.gov (United States)

Imhoff, M.; Bounoua, L.

2004-12-01

A unique combination of satellite and socio-economic data were used to explore the relationship between human consumption and the carbon cycle. Biophysical models were applied to consumption data to estimate the annual amount of Earth's terrestrial net primary production humans require for food, fiber and fuel using the same modeling architecture as satellite-supported NPP measurements. The amount of Earth's NPP required to support human activities is a powerful measure of the aggregate human impacts on the biosphere and indicator of societal vulnerability to climate change. Equations were developed estimating the amount of landscape-level NPP required to generate all the products consumed by 230 countries including; vegetal foods, meat, milk, eggs, wood, fuel-wood, paper and fiber. The amount of NPP required was calculated on a per capita basis and projected onto a global map of population to create a spatially explicit map of NPP-carbon demand in units of elemental carbon. NPP demand was compared to a map of Earth's average annual net primary production or supply created using 17 years (1982-1998) of AVHRR vegetation index to produce a geographically accurate balance sheet of terrestrial NPP-carbon supply and demand. Globally, humans consume 20 percent of Earth's total net primary production on land. Regionally the NPP-carbon balance percentage varies from 6 to over 70 percent and locally from near 0 to over 30,000 percent in major urban areas. The uneven distribution of NPP-carbon supply and demand, indicate the degree to which various human populations rely on NPP imports, are vulnerable to climate change and suggest policy options for slowing future growth in NPP demand.

Estimating root biomass and distribution after fire in a Great Basin woodland using cores and pits

Science.gov (United States)

Benjamin M. Rau; Dale W. Johnson; Jeanne C. Chambers; Robert R. Blank; Annmarie Lucchesi

2009-01-01

Quantifying root biomass is critical to an estimation and understanding of ecosystem net primary production, biomass partitioning, and belowground competition. We compared 2 methods for determining root biomass: a new soil-coring technique and traditional excavation of quantitative pits. We conducted the study in an existing Joint Fire Sciences demonstration area in...

The importance of aboveground–belowground interactions on the evolution and maintenance of variation in plant defense traits

Science.gov (United States)

van Geem, Moniek; Gols, Rieta; van Dam, Nicole M.; van der Putten, Wim H.; Fortuna, Taiadjana; Harvey, Jeffrey A.

2013-01-01

Over the past two decades a growing body of empirical research has shown that many ecological processes are mediated by a complex array of indirect interactions occurring between rhizosphere-inhabiting organisms and those found on aboveground plant parts. Aboveground–belowground studies have thus far focused on elucidating processes and underlying mechanisms that mediate the behavior and performance of invertebrates in opposite ecosystem compartments. Less is known about genetic variation in plant traits such as defense as that may be driven by above- and belowground trophic interactions. For instance, although our understanding of genetic variation in aboveground plant traits and its effects on community-level interactions is well developed, little is known about the importance of aboveground–belowground interactions in driving this variation. Plant traits may have evolved in response to selection pressures from above- and below-ground interactions from antagonists and mutualists. Here, we discuss gaps in our understanding of genetic variation in plant-related traits as they relate to aboveground and belowground multitrophic interactions. When metabolic resources are limiting, multiple attacks by antagonists in both domains may lead to trade-offs. In nature, these trade-offs may critically depend upon their effects on plant fitness. Natural enemies of herbivores may also influence selection for different traits via top–down control. At larger scales these interactions may generate evolutionary “hotspots” where the expression of various plant traits is the result of strong reciprocal selection via direct and indirect interactions. The role of abiotic factors in driving genetic variation in plant traits is also discussed. PMID:24348484

Estimating crop net primary production using inventory data and MODIS-derived parameters

Energy Technology Data Exchange (ETDEWEB)

Bandaru, Varaprasad; West, Tristram O.; Ricciuto, Daniel M.; Izaurralde, Roberto C.

2013-06-03

National estimates of spatially-resolved cropland net primary production (NPP) are needed for diagnostic and prognostic modeling of carbon sources, sinks, and net carbon flux. Cropland NPP estimates that correspond with existing cropland cover maps are needed to drive biogeochemical models at the local scale and over national and continental extents. Existing satellite-based NPP products tend to underestimate NPP on croplands. A new Agricultural Inventory-based Light Use Efficiency (AgI-LUE) framework was developed to estimate individual crop biophysical parameters for use in estimating crop-specific NPP. The method is documented here and evaluated for corn and soybean crops in Iowa and Illinois in years 2006 and 2007. The method includes a crop-specific enhanced vegetation index (EVI) from the Moderate Resolution Imaging Spectroradiometer (MODIS), shortwave radiation data estimated using Mountain Climate Simulator (MTCLIM) algorithm and crop-specific LUE per county. The combined aforementioned variables were used to generate spatially-resolved, crop-specific NPP that correspond to the Cropland Data Layer (CDL) land cover product. The modeling framework represented well the gradient of NPP across Iowa and Illinois, and also well represented the difference in NPP between years 2006 and 2007. Average corn and soybean NPP from AgI-LUE was 980 g C m-2 yr-1 and 420 g C m-2 yr-1, respectively. This was 2.4 and 1.1 times higher, respectively, for corn and soybean compared to the MOD17A3 NPP product. Estimated gross primary productivity (GPP) derived from AgI-LUE were in close agreement with eddy flux tower estimates. The combination of new inputs and improved datasets enabled the development of spatially explicit and reliable NPP estimates for individual crops over large regional extents.

Net primary productivity (NPP) and associated parameters for the U.S. outer continental shelf waters, 1998-2009 (NODC Accession 0071184)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This accession consists of monthly net primary productivity (NPP) estimates for 1998-2009 derived from the Vertically Generalized Production Model (VGPM) for the 26...

Carbon dioxide flux and net primary production of a boreal treed bog: Responses to warming and water-table-lowering simulations of climate change

Science.gov (United States)

Munir, T. M.; Perkins, M.; Kaing, E.; Strack, M.

2015-02-01

Midlatitude treed bogs represent significant carbon (C) stocks and are highly sensitive to global climate change. In a dry continental treed bog, we compared three sites: control, recent (1-3 years; experimental) and older drained (10-13 years), with water levels at 38, 74 and 120 cm below the surface, respectively. At each site we measured carbon dioxide (CO2) fluxes and estimated tree root respiration (Rr; across hummock-hollow microtopography of the forest floor) and net primary production (NPP) of trees during the growing seasons (May to October) of 2011-2013. The CO2-C balance was calculated by adding the net CO2 exchange of the forest floor (NEff-Rr) to the NPP of the trees. From cooler and wetter 2011 to the driest and the warmest 2013, the control site was a CO2-C sink of 92, 70 and 76 g m-2, the experimental site was a CO2-C source of 14, 57 and 135 g m-2, and the drained site was a progressively smaller source of 26, 23 and 13 g CO2-C m-2. The short-term drainage at the experimental site resulted in small changes in vegetation coverage and large net CO2 emissions at the microforms. In contrast, the longer-term drainage and deeper water level at the drained site resulted in the replacement of mosses with vascular plants (shrubs) on the hummocks and lichen in the hollows leading to the highest CO2 uptake at the drained hummocks and significant losses in the hollows. The tree NPP (including above- and below-ground growth and litter fall) in 2011 and 2012 was significantly higher at the drained site (92 and 83 g C m-2) than at the experimental (58 and 55 g C m-2) and control (52 and 46 g C m-2) sites. We also quantified the impact of climatic warming at all water table treatments by equipping additional plots with open-top chambers (OTCs) that caused a passive warming on average of ~ 1 °C and differential air warming of ~ 6 °C at midday full sun over the study years. Warming significantly enhanced shrub growth and the CO2 sink function of the drained

THE EFFECT OF OZONE ON BELOW-GROUND CARBON ALLOCATION IN WHEAT

Science.gov (United States)

Short term 14CO2 pulse and chase experiments were conducted in order to investigate the effect ozone on below-ground carbon allocation in spring wheat seedlings (Triticum aestivumL. ?ANZA'). Wheat seedlings were grown in a sand-hydroponic system and exposed to either high ozone ...

Potential remobilization of belowground permafrost carbon under future global warming

Science.gov (United States)

P. Kuhry; E. Dorrepaal; G. Hugelius; E.A.G. Schuur; C. Tarnocai

2010-01-01

Research on permafrost carbon has dramatically increased in the past few years. A new estimate of 1672 Pg C of belowground organic carbon in the northern circumpolar permafrost region more than doubles the previous value and highlights the potential role of permafrost carbon in the Earth System. Uncertainties in this new estimate remain due to relatively few available...

Worldwide estimates and bibliography of net primary productivity derived from pre-1982 publications

Energy Technology Data Exchange (ETDEWEB)

Esser, G. [Justus-Liebig-Univ., Giessen (Germany). Inst. for Plant Ecology; Lieth, H.F.H. [Univ. of Osnabrueck (Germany). Systems Research Group; Scurlock, J.M.O.; Olson, R.J. [Oak Ridge National Lab., TN (United States)

1997-10-01

An extensive compilation of more than 700 field estimates of net primary productivity of natural and agricultural ecosystems worldwide was synthesized in Germany in the 1970s and early 1980s. Although the Osnabrueck data set has not been updated since the 1980s, it represents a wealth of information for use in model development and validation. This report documents the development of this data set, its contents, and its recent availability on the Internet from the Oak Ridge National Laboratory Distributed Active Archive Center for Biogeochemical Dynamics. Caution is advised in using these data, which necessarily include assumptions and conversions that may not be universally applicable to all sites.

Aboveground and belowground arthropods experience different relative influences of stochastic versus deterministic community assembly processes following disturbance

Directory of Open Access Journals (Sweden)

Scott Ferrenberg

2016-10-01

Full Text Available Background Understanding patterns of biodiversity is a longstanding challenge in ecology. Similar to other biotic groups, arthropod community structure can be shaped by deterministic and stochastic processes, with limited understanding of what moderates the relative influence of these processes. Disturbances have been noted to alter the relative influence of deterministic and stochastic processes on community assembly in various study systems, implicating ecological disturbances as a potential moderator of these forces. Methods Using a disturbance gradient along a 5-year chronosequence of insect-induced tree mortality in a subalpine forest of the southern Rocky Mountains, Colorado, USA, we examined changes in community structure and relative influences of deterministic and stochastic processes in the assembly of aboveground (surface and litter-active species and belowground (species active in organic and mineral soil layers arthropod communities. Arthropods were sampled for all years of the chronosequence via pitfall traps (aboveground community and modified Winkler funnels (belowground community and sorted to morphospecies. Community structure of both communities were assessed via comparisons of morphospecies abundance, diversity, and composition. Assembly processes were inferred from a mixture of linear models and matrix correlations testing for community associations with environmental properties, and from null-deviation models comparing observed vs. expected levels of species turnover (Beta diversity among samples. Results Tree mortality altered community structure in both aboveground and belowground arthropod communities, but null models suggested that aboveground communities experienced greater relative influences of deterministic processes, while the relative influence of stochastic processes increased for belowground communities. Additionally, Mantel tests and linear regression models revealed significant associations between the

Aboveground and belowground arthropods experience different relative influences of stochastic versus deterministic community assembly processes following disturbance

Science.gov (United States)

Martinez, Alexander S.; Faist, Akasha M.

2016-01-01

Background Understanding patterns of biodiversity is a longstanding challenge in ecology. Similar to other biotic groups, arthropod community structure can be shaped by deterministic and stochastic processes, with limited understanding of what moderates the relative influence of these processes. Disturbances have been noted to alter the relative influence of deterministic and stochastic processes on community assembly in various study systems, implicating ecological disturbances as a potential moderator of these forces. Methods Using a disturbance gradient along a 5-year chronosequence of insect-induced tree mortality in a subalpine forest of the southern Rocky Mountains, Colorado, USA, we examined changes in community structure and relative influences of deterministic and stochastic processes in the assembly of aboveground (surface and litter-active species) and belowground (species active in organic and mineral soil layers) arthropod communities. Arthropods were sampled for all years of the chronosequence via pitfall traps (aboveground community) and modified Winkler funnels (belowground community) and sorted to morphospecies. Community structure of both communities were assessed via comparisons of morphospecies abundance, diversity, and composition. Assembly processes were inferred from a mixture of linear models and matrix correlations testing for community associations with environmental properties, and from null-deviation models comparing observed vs. expected levels of species turnover (Beta diversity) among samples. Results Tree mortality altered community structure in both aboveground and belowground arthropod communities, but null models suggested that aboveground communities experienced greater relative influences of deterministic processes, while the relative influence of stochastic processes increased for belowground communities. Additionally, Mantel tests and linear regression models revealed significant associations between the aboveground arthropod

Early root overproduction not triggered by nutrients decisive for competitive success belowground

NARCIS (Netherlands)

Padilla, F.M.; Mommer, L.; Caluwe, de H.; Smit-Tiekstra, A.E.; Wagemaker, C.A.M.; Ouborg, N.J.; Kroon, de H.

2013-01-01

Background - Theory predicts that plant species win competition for a shared resource by more quickly preempting the resource in hotspots and by depleting resource levels to lower concentrations than its competitors. Competition in natural grasslands largely occurs belowground, but information

Empirical and theoretical challenges in aboveground-belowground ecology

DEFF Research Database (Denmark)

W.H. van der Putten,; R.D. Bardgett; P.C. de Ruiter

2009-01-01

of the current conceptual succession models into more predictive models can help targeting empirical studies and generalising their results. Then, we discuss how understanding succession may help to enhance managing arable crops, grasslands and invasive plants, as well as provide insights into the effects...... and environmental settings, we explore where and how they can be supported by theoretical approaches to develop testable predictions and to generalise empirical results. We review four key areas where a combined aboveground-belowground approach offers perspectives for enhancing ecological understanding, namely...

Above- and belowground competition from longleaf pine plantations limits performance of reintroduced herbaceous species.

Energy Technology Data Exchange (ETDEWEB)

T.B. Harrington; C.M. Dagley; M.B. Edwards.

2003-10-01

Although overstory trees limit the abundance and species richness of herbaceous vegetation in longleaf pine (Pinus palustris Mill.) plantations, the responsible mechanisms are poorly understood because of confounding among limiting factors. In fall 1998, research was initiated to determine the separate effects of above- and belowground competition and needlefall from overstory pines on understory plant performance. Three 13- to 15-yr-old plantations near Aiken, SC, were thinned to 0, 25, 50, or 100% of nonthinned basal area (19.5 m2 ha-1). Combinations of trenching (to eliminate root competition) and needlefall were applied to areas within each plot, and containerized seedlings of 14 perennial herbaceous species and longleaf pine were planted within each. Overstory crown closure ranged from 0 to 81%, and soil water and available nitrogen varied consistently with pine stocking, trenching, or their combination. Cover of planted species decreased an average of 16.5 and 14.1% as a result of above- and below-ground competition, respectively. Depending on species, needlefall effects were positive, negative, or negligible. Results indicate that understory restoration will be most successful when herbaceous species are established within canopy openings (0.1-0.2 ha) managed to minimize negative effects from above- and belowground competition and needlefall.

Effects of belowground litter addition, increased precipitation and clipping on soil carbon and nitrogen mineralization in a temperate steppe

OpenAIRE

Ma, L.; Guo, C.; Xin, X.; Yuan, S.; Wang, R.

2013-01-01

Soil carbon (C) and nitrogen (N) cycling are sensitive to changes in environmental factors and play critical roles in the responses of terrestrial ecosystems to natural and anthropogenic perturbations. This study was conducted to quantify the effects of belowground particulate litter (BPL) addition, increased precipitation and their interactions on soil C and N mineralization in two adjacent sites where belowground photosynthate allocation was manipulated through vegetation ...

Above and belowground controls on litter decomposition in semiarid ecosystems: effects of solar radiation, water availability and litter quality

Science.gov (United States)

Austin, A. T.; Araujo, P. I.; Leva, P. E.; Ballare, C. L.

2008-12-01

The integrated controls on soil organic matter formation in arid and semiarid ecosystems are not well understood and appear to stem from a number of interacting controls affecting above- and belowground carbon turnover. While solar radiation has recently been shown to have an important direct effect on carbon loss in semiarid ecosystems as a result of photochemical mineralization of aboveground plant material, the mechanistic basis for photodegradative losses is poorly understood. In addition, there are large potential differences in major controls on above- and belowground decomposition in low rainfall ecosystems. We report on a mesocosm and field study designed to examine the relative importance of different wavelengths of solar radiation, water availability, position of senescent material above- and belowground and the importance of carbon litter quality in determining rates of abiotic and biotic decomposition. In a factorial experiment of mesocosms, we incubated leaf and root litter simultaneously above- and belowground and manipulated water availability with large and small pulses. Significant interactions between position-litter type and position-pulse sizes demonstrated interactive controls on organic mass loss. Aboveground decomposition showed no response to pulse size or litter type, as roots and leaves decomposed equally rapidly under all circumstances. In contrast, belowground decomposition was significantly altered by litter type and water pulses, with roots decomposing significantly slower and small water pulses reducing belowground decomposition. In the field site, using plastic filters which attenuated different wavelengths of natural solar radiation, we found a highly significant effect of radiation exclusion on mass loss and demonstrated that both UV-A and short-wave visible light can have important impacts on photodegradative carbon losses. The combination of position and litter quality effects on litter decomposition appear to be critical for the

Seasonal Oxygen Dynamics in a Warm Temperate Estuary: Effects of Hydrologic Variability on Measurements of Primary Production, Respiration, and Net Metabolism

Science.gov (United States)

Seasonal responses in estuarine metabolism (primary production, respiration, and net metabolism) were examined using two complementary approaches. Total ecosystem metabolism rates were calculated from dissolved oxygen time series using Odum’s open water method. Water column rates...

Plant-Mediated Systemic Interactions Between Pathogens, Parasitic Nematodes, and Herbivores Above- and Belowground

NARCIS (Netherlands)

Biere, A.; Goverse, A.

2016-01-01

Plants are important mediators of interactions between aboveground (AG) and belowground (BG) pathogens, arthropod herbivores, and nematodes (phytophages). We highlight recent progress in our understanding of within- and cross-compartment plant responses to these groups of phytophages in terms of

Plant-mediated systemic interactions between pathogens, parasitic nematodes, and herbivores above- and belowground

NARCIS (Netherlands)

Biere, A.; Goverse, Aska

2016-01-01

Plants are important mediators of interactions between aboveground (AG) and belowground (BG) pathogens, arthropod herbivores, and nematodes (phytophages). We highlight recent progress in our understanding of within and cross-compartment plant responses to these groups of phytophages in terms of

Observation and simulation of net primary productivity in Qilian Mountain, western China.

Science.gov (United States)

Zhou, Y; Zhu, Q; Chen, J M; Wang, Y Q; Liu, J; Sun, R; Tang, S

2007-11-01

We modeled net primary productivity (NPP) at high spatial resolution using an advanced spaceborne thermal emission and reflection radiometer (ASTER) image of a Qilian Mountain study area using the boreal ecosystem productivity simulator (BEPS). Two key driving variables of the model, leaf area index (LAI) and land cover type, were derived from ASTER and moderate resolution imaging spectroradiometer (MODIS) data. Other spatially explicit inputs included daily meteorological data (radiation, precipitation, temperature, humidity), available soil water holding capacity (AWC), and forest biomass. NPP was estimated for coniferous forests and other land cover types in the study area. The result showed that NPP of coniferous forests in the study area was about 4.4 tCha(-1)y(-1). The correlation coefficient between the modeled NPP and ground measurements was 0.84, with a mean relative error of about 13.9%.

Ecological studies in a Scanian woodland and meadow area, southern Sweden. Ti. Plant biomass, primary production and turnover of organic matter

Energy Technology Data Exchange (ETDEWEB)

Andersson, F

1970-01-01

As a part of an IBP project the productivity of the south Swedish deciduous woodland ecosystems and their secondary successional stages a comparison between the distribution of organic matter in a mixed deciduous woodland dominated by Quercus robur, Tilia cordata, Corylus avellana and Anemone nemorosa and a tall herb meadow with Filipendula ulmaria within the nemoral zone in the southernmost part of Sweden has been made. Estimations of the plant biomass and production in the woodland was made by a dimension analysis applying allometric equations. A total plant biomass of 240 t/ha was found with 201 t/ha and 39 t/ha as above-and below-ground figures respectively. The corresponding figures of the net primary production are 15.6, 13.3 and 2.3 t/ha. A production of 0.77 t/ha is included for the above-ground production of the field layer. The litter fall, fractions less than 50 cm long, during a three year period amounted to 5.28 t/ha with considerable variation between years. Including coarser litter fractions an yearly input to the ground of 6.5 t/ha was found. After estimation of the remaining litter before the leaf fall, 6.1 t/ha, the yearly turnover of the litter layer is calculated to 52%. As the humus fraction amounts to 218 t/ha, the total content of organic matter in the woodland ecosystem thus is 463 t/ha with an almost equal distribution between above-and below-ground portions. In the meadow the distribution of above-and below-ground portions of the organic matter is 1/49, calculated from the following figures: Above-ground biomass 4.7 t/ha, below-ground biomass 13.2 t/ha, surface litter 2.4 t/ha and humus 304 t/ha making the total organic matter of the meadow ecosystem 324 t/ha. The yearly above-ground production is estimated to be 7.2 t/ha and taking this as the yearly litter input to the ground and taking the remaining litter into account a turnover of the litter layer 75% is calculated.

Spatial scaling of net primary productivity using subpixel landcover information

Science.gov (United States)

Chen, X. F.; Chen, Jing M.; Ju, Wei M.; Ren, L. L.

2008-10-01

Gridding the land surface into coarse homogeneous pixels may cause important biases on ecosystem model estimations of carbon budget components at local, regional and global scales. These biases result from overlooking subpixel variability of land surface characteristics. Vegetation heterogeneity is an important factor introducing biases in regional ecological modeling, especially when the modeling is made on large grids. This study suggests a simple algorithm that uses subpixel information on the spatial variability of land cover type to correct net primary productivity (NPP) estimates, made at coarse spatial resolutions where the land surface is considered as homogeneous within each pixel. The algorithm operates in such a way that NPP obtained from calculations made at coarse spatial resolutions are multiplied by simple functions that attempt to reproduce the effects of subpixel variability of land cover type on NPP. Its application to a carbon-hydrology coupled model(BEPS-TerrainLab model) estimates made at a 1-km resolution over a watershed (named Baohe River Basin) located in the southwestern part of Qinling Mountains, Shaanxi Province, China, improved estimates of average NPP as well as its spatial variability.

Productive vegetation: relationships between net primary productivity, vegetation types and climate change in the Wet Tropics bioregion

International Nuclear Information System (INIS)

Ramirez, Vanessa Valdez; Williams, Stephen E.; VanDerWal, Jeremy

2007-01-01

Full text: Full text: There is now ample evidence demonstrating the impacts of climate change on biodiversity and human society (Walther ef a/. 2002). Numerous studies have shown climate change is one of the most significant threats to tropical forests, such as the Wet Tropics Heritage Area, due to their high biodiversity and endemism (Pounds ef al. 1999; Hughes 2000; Parmesan and Yohe 2003). Williams ef al. (2003) suggested that small shifts in net primary productivity (NPP) as a result of climate change could lead to potentially massive follow-on effects for the extremely diverse and vulnerable rainforest flora and fauna. It is therefore crucial to explore the relationships between NPP and local biodiversity, especially to create models for different climate change scenarios. Nevertheless, NPP in the Wet Tropics has yet to be estimated. This is the first study to provide a general NPP estimate for the Wet Tropics bioregion using climate surrogates (Schuur 2003). This technique estimates NPP in an accurate, repeatable, and cost-effective way. NPP values were linked to vegetation types and examined under various climatic and environmental conditions. Results show a significant difference in productivity according to vegetation types and climatic variables, with temperature and rainfall seasonality as the most important determining variables. Additionally, lowland and upland vegetations showed a significant difference in productivity patterns throughout the year. Vegetation types located above 1000 metres in altitude had the lowest values of mean annual productivity due to their high rainfall and low temperatures; vegetation types located below 600 metres showed increased productivity values during the wet season (December-March). Net primary productivity will certainly be impacted by changes in temperature and rainfall, due to climate change. Although an increase in NPP values can be predicted for upland areas, the more widely distributed lowlands will drastically

UV-B-mediated changes on below-ground communities associated with the roots of Acer saccharum

International Nuclear Information System (INIS)

Klironomos, J.N.; Allen, M.F.

1995-01-01

1. Little is known about how exposure to UV-B radiation affects rhizosphere microbes. Rhizosphere organisms are fed primarily by root-derived substrates and fulfil functions such as mineralization, immobilization, decomposition, pathogeneity and improvement of plant nutrition; they form the base of the below-ground food web. 2. In this study, we exposed Sugar Maple (Acer saccharum) seedlings to UV-B radiation in order to determine if UV-B influences the activities of mycorrhizal and non-mycorrhizal fungi, bacteria and microbe-feeding arthropods in the rhizosphere. 3. Below-ground organisms are greatly affected by UV-B radiation. Overall, carbon-flow in the plant soil system was shifted from a mutualistic-closed, mycorrhizal-dominated system to an opportunist-open, saprobe/pathogen-dominated one. (author)

Belowground carabid beetle diversity in the western Palaearctic – effects of history and climate on range-restricted taxa (Coleoptera, Carabidae

Directory of Open Access Journals (Sweden)

Andreas Schuldt

2011-05-01

Full Text Available Broad-scale patterns of subterranean diversity are a fascinating but neglected part of biodiversity research. Carabid beetles adapted to belowground habitats form a particularly species-rich part of the subterranean fauna. We studied large-scale diversity patterns of these belowground carabids across the western Palaearctic and evaluated potential impacts of historical and contemporary environmental conditions on the distribution of these taxa, using available species richness and environmental data at country level. Regression modelling and variation partitioning showed a strong relationship between species richness and range in elevation. Potential effects of climatic variables, mainly those related to ambient energy input, were much weaker. We discuss the implications of this combination of effects, which suggests, concordant with the absence of subterranean carabids in northern and highest richness in southern Europe, a strong prevailing influence of historical processes on current richness distributions of these taxa. Previous studies did not provide clear indications for such an influence. In contrast to more mobile and widespread carabid beetles, dispersal limitation due to high adaptation of belowground carabids to subterranean habitats has probably hindered their re-colonization of former permafrost and glaciated regions. Hotspots of highest belowground diversity are located in regions with an assumed long-term stability of environmental conditions, correlating with patterns of other dispersal-limited taxa such as many endemic plants. Our study provides important new information in the discussion of potential determinants of the distinct geographic patterns of belowground diversity. Moreover, it contributes to a better understanding of range size related differences previously found in the distribution of diversity and environmental dependencies of widespread and range-restricted species within the highly diverse carabid beetles.

Effects of Climate Change and Shifts in Forest Composition on Forest Net Primary Production

Institute of Scientific and Technical Information of China (English)

Jyh-Min Chiang; Louts R. Iverson; Anantha Prasad; Kim J. Brown

2008-01-01

Forests are dynamic in both structure and species composition, and these dynamics are strongly Influenced by climate.However, the net effects of future tree species composition on net primary production (NPP) are not well understood. The objective of this work was to model the potential range shifts of tree species (DISTRIB Model) and predict their impacts on NPP (PnET-Ⅱ Model) that will be associated with alterations in species composition. We selected four 200 × 200 km areas In Wisconsin, Maine, Arkansas, and the Ohio-West Virginia area, representing focal areas of potential species range shifts. PnET-Ⅱ model simulations were carried out assuming that all forests achieved steady state, of which the species compositions were predicted by DISTRIB model with no migration limitation. The total NPP under the current climate ranged from 552 to 908 g C/m2 per year. The effects of potential species redistributions on NPP were moderate (-12% to +8%) compared with the influence of future climatic changes (-60% to +25%). The direction and magnitude of climate change effects on NPP were largely dependent on the degree of warming and water balance. Thus, the magnitude of future climate change can affect the feedback system between the atmosphere and biosphere.

Mechanisms and ecological implications of plant-mediated interactions between belowground and aboveground insect herbivores

NARCIS (Netherlands)

Papadopoulou, G.V.; Dam, N.M. van

2017-01-01

Plant-mediated interactions between belowground (BG) and aboveground (AG) herbivores have received increasing interest recently. However, the molecular mechanisms underlying ecological consequences of BG–AG interactions are not fully clear yet. Herbivore-induced plant defenses are complex and

A hybrid model for mapping relative differences in belowground biomass and root: Shoot ratios using spectral reflectance, foliar N and plant biophysical data within coastal marsh

Science.gov (United States)

Jessica L. O'Connell,; Byrd, Kristin B.; Maggi Kelly,

2015-01-01

Broad-scale estimates of belowground biomass are needed to understand wetland resiliency and C and N cycling, but these estimates are difficult to obtain because root:shoot ratios vary considerably both within and between species. We used remotely-sensed estimates of two aboveground plant characteristics, aboveground biomass and % foliar N to explore biomass allocation in low diversity freshwater impounded peatlands (Sacramento-San Joaquin River Delta, CA, USA). We developed a hybrid modeling approach to relate remotely-sensed estimates of % foliar N (a surrogate for environmental N and plant available nutrients) and aboveground biomass to field-measured belowground biomass for species specific and mixed species models. We estimated up to 90% of variation in foliar N concentration using partial least squares (PLS) regression of full-spectrum field spectrometer reflectance data. Landsat 7 reflectance data explained up to 70% of % foliar N and 67% of aboveground biomass. Spectrally estimated foliar N or aboveground biomass had negative relationships with belowground biomass and root:shoot ratio in both Schoenoplectus acutus and Typha, consistent with a balanced growth model, which suggests plants only allocate growth belowground when additional nutrients are necessary to support shoot development. Hybrid models explained up to 76% of variation in belowground biomass and 86% of variation in root:shoot ratio. Our modeling approach provides a method for developing maps of spatial variation in wetland belowground biomass.

Net primary productivity of some aquatic macrophytes in sewage-sullage mixture.

Science.gov (United States)

Kanungo, V K; Sinha, S; Naik, M L

2001-07-01

Sewage-sullage mixture from Raipur city is spread over a vast area surrounding the city. This mixture has a pH always above neutrality with high turbidity. Transparency was nil with the absence of phenolphthalein alkalinity and dissolved oxygen. Hardness was high with low nitrogen and phosphorus concentration. Human consumable. acquatic macrophytes are cultivated in such waste water. Net primary productivity of three macrophytes: Ipomoea aquatica, Marsilea quadrifolia and Nelumbo nucifera were evaluated while being cultivated in such sewage-sullage mixture. Productivity was determined either with periodic biomass removal (I. aquatica and M. quadrifolia) or through removing the biomass only once at the time of growing season (N. nucifera). Growing season productivity of up to 27.48. 19.81 and 9.49 g m(-2) and day(-1) and extrapolated productivity of up to 100.30, 72.31 and 34.64 mt. ha(-1) yr(-1) was recorded for I. aquatica. M. quadrifolia and N. nucifera respectively. Thus, these macrophytes are yielding a high amount of human consumable biomass from an area which neither be a useless wetland.

Belowground legacies of Pinus contorta invasion and removal result in multiple mechanisms of invasional meltdown.

Science.gov (United States)

Dickie, Ian A; St John, Mark G; Yeates, Gregor W; Morse, Chris W; Bonner, Karen I; Orwin, Kate; Peltzer, Duane A

2014-01-01

Plant invasions can change soil biota and nutrients in ways that drive subsequent plant communities, particularly when co-invading with belowground mutualists such as ectomycorrhizal fungi. These effects can persist following removal of the invasive plant and, combined with effects of removal per se, influence subsequent plant communities and ecosystem functioning. We used field observations and a soil bioassay with multiple plant species to determine the belowground effects and post-removal legacy caused by invasion of the non-native tree Pinus contorta into a native plant community. Pinus facilitated ectomycorrhizal infection of the co-occurring invasive tree, Pseudotsuga menziesii, but not conspecific Pinus (which always had ectomycorrhizas) nor the native pioneer Kunzea ericoides (which never had ectomycorrhizas). Pinus also caused a major shift in soil nutrient cycling as indicated by increased bacterial dominance, NO3-N (17-fold increase) and available phosphorus (3.2-fold increase) in soils, which in turn promoted increased growth of graminoids. These results parallel field observations, where Pinus removal is associated with invasion by non-native grasses and herbs, and suggest that legacies of Pinus on soil nutrient cycling thus indirectly promote invasion of other non-native plant species. Our findings demonstrate that multi-trophic belowground legacies are an important but hitherto largely unconsidered factor in plant community reassembly following invasive plant removal. Published by Oxford University Press on behalf of the Annals of Botany Company.

Aboveground vertebrate and invertebrate herbivore impact on net N mineralization in subalpine grasslands.

Science.gov (United States)

Risch, Anita C; Schotz, Martin; Vandegehuchte, Martijn L; Van Der Putten, Wim H; Duyts, Henk; Raschein, Ursina; Gwiazdowicz, Dariusz J; Busse, Matt D; Page-dumroese, Deborah S; Zimmermann, Stephan

2015-12-01

. The negative impact of mammals on net N mineralization may be related partially to (1) differences in the amount of plant material (litter) returned to the belowground subsystem, which induced a positive bottom-up effect on mite abundance, and (2) alterations in the amount and/or distribution of dung, urine, and food waste. Thus, our results clearly show that short-term alterations of the aboveground herbivore community can strongly impact nutrient cycling within ecosystems independent of long-term management and grazing history.

Incorporating climate into belowground carbon estimates in the national greenhouse gas inventory

Science.gov (United States)

Matthew B. Russell; Grant M. Domke; Christopher W. Woodall; Anthony W. D’Amato

2015-01-01

Refined estimation of carbon (C) stocks within forest ecosystems is a critical component of efforts to reduce greenhouse gas emissions and mitigate the effects of projected climate change through forest C management. Recent evidence has pointed to the importance of climate as a driver of belowground C stocks. This study describes an approach for adjusting allometric...

Net primary production and canopy nitrogen in a temperate forest landscape: an analysis using imaging spectroscopy, modeling and field data

Science.gov (United States)

Scott V. Ollinger; Marie-Louise Smith

2005-01-01

Understanding spatial patterns of net primary production (NPP) is central to the study of terrestrial ecosystems, but efforts are frequently hampered by a lack of spatial information regarding factors such as nitrogen availability and site history. Here, we examined the degree to which canopy nitrogen can serve as an indicator of patterns of NPP at the Bartlett...

Impacts of Jatropha-based biodiesel production on above and below-ground carbon stocks: A case study from Mozambique

International Nuclear Information System (INIS)

Vang Rasmussen, Laura; Rasmussen, Kjeld; Bech Bruun, Thilde

2012-01-01

The need to mitigate climate change makes production of liquid biofuels a high priority. Substituting fossil fuels by biodiesel produced from Jatropha curcas has gained widespread attention as Jatropha cultivation is claimed to offer green house gas emission reductions. Farmers respond worldwide to this increasing demand by converting forests into Jatropha, but whether Jatropha-based biodiesel offers carbon savings depends on the carbon emissions that occur when land use is changed to Jatropha. This paper provides an impact assessment of a small-scale Jatropha project in Cabo Delgado, Mozambique. The paper outlines the estimated impacts on above and below-ground carbon stocks when land use is changed to increase Jatropha production. The results show that expansion of Jatropha production will most likely lead to the conversion of miombo forest areas to Jatropha, which implies a reduction in above and below-ground carbon stocks. The carbon debts created by the land use change can be repaid by replacing fossil fuels with Jatropha-based biodiesel. A repayment time of almost two centuries is found with optimistic estimates of the carbon debt, while the use of pessimistic values results in a repayment time that approaches the millennium. - Highlights: ► Demands for biofuels make production of Jatropha-based biodiesel a priority. ► Farmers in Northern Mozambique are likely to convert un-logged miombo to Jatropha. ► Converting miombo to Jatropha creates reductions in above and below-ground carbon. ► It takes 187–966 years to repay emissions from above and below-ground carbon stocks.

Variability in above- and belowground carbon stocks in a Siberian larch watershed

Directory of Open Access Journals (Sweden)

E. E. Webb

2017-09-01

Full Text Available Permafrost soils store between 1330 and 1580 Pg carbon (C, which is 3 times the amount of C in global vegetation, almost twice the amount of C in the atmosphere, and half of the global soil organic C pool. Despite the massive amount of C in permafrost, estimates of soil C storage in the high-latitude permafrost region are highly uncertain, primarily due to undersampling at all spatial scales; circumpolar soil C estimates lack sufficient continental spatial diversity, regional intensity, and replication at the field-site level. Siberian forests are particularly undersampled, yet the larch forests that dominate this region may store more than twice as much soil C as all other boreal forest types in the continuous permafrost zone combined. Here we present above- and belowground C stocks from 20 sites representing a gradient of stand age and structure in a larch watershed of the Kolyma River, near Chersky, Sakha Republic, Russia. We found that the majority of C stored in the top 1 m of the watershed was stored belowground (92 %, with 19 % in the top 10 cm of soil and 40 % in the top 30 cm. Carbon was more variable in surface soils (10 cm; coefficient of variation (CV  =  0.35 between stands than in the top 30 cm (CV  =  0.14 or soil profile to 1 m (CV  =  0.20. Combined active-layer and deep frozen deposits (surface – 15 m contained 205 kg C m−2 (yedoma, non-ice wedge and 331 kg C m−2 (alas, which, even when accounting for landscape-level ice content, is an order of magnitude more C than that stored in the top meter of soil and 2 orders of magnitude more C than in aboveground biomass. Aboveground biomass was composed of primarily larch (53 % but also included understory vegetation (30 %, woody debris (11 % and snag (6 % biomass. While aboveground biomass contained relatively little (8 % of the C stocks in the watershed, aboveground processes were linked to thaw depth and

Improved assessment of gross and net primary productivity of Canada's landmass

Science.gov (United States)

Gonsamo, Alemu; Chen, Jing M.; Price, David T.; Kurz, Werner A.; Liu, Jane; Boisvenue, Céline; Hember, Robbie A.; Wu, Chaoyang; Chang, Kuo-Hsien

2013-12-01

assess Canada's gross primary productivity (GPP) and net primary productivity (NPP) using boreal ecosystem productivity simulator (BEPS) at 250 m spatial resolution with improved input parameter and driver fields and phenology and nutrient release parameterization schemes. BEPS is a process-based two-leaf enzyme kinetic terrestrial ecosystem model designed to simulate energy, water, and carbon (C) fluxes using spatial data sets of meteorology, remotely sensed land surface variables, soil properties, and photosynthesis and respiration rate parameters. Two improved key land surface variables, leaf area index (LAI) and land cover type, are derived at 250 m from Moderate Resolution Imaging Spectroradiometer sensor. For diagnostic error assessment, we use nine forest flux tower sites where all measured C flux, meteorology, and ancillary data sets are available. The errors due to input drivers and parameters are then independently corrected for Canada-wide GPP and NPP simulations. The optimized LAI use, for example, reduced the absolute bias in GPP from 20.7% to 1.1% for hourly BEPS simulations. Following the error diagnostics and corrections, daily GPP and NPP are simulated over Canada at 250 m spatial resolution, the highest resolution simulation yet for the country or any other comparable region. Total NPP (GPP) for Canada's land area was 1.27 (2.68) Pg C for 2008, with forests contributing 1.02 (2.2) Pg C. The annual comparisons between measured and simulated GPP show that the mean differences are not statistically significant (p > 0.05, paired t test). The main BEPS simulation error sources are from the driver fields.

Game Theory .net.

Science.gov (United States)

Shor, Mikhael

2003-01-01

States making game theory relevant and accessible to students is challenging. Describes the primary goal of GameTheory.net is to provide interactive teaching tools. Indicates the site strives to unite educators from economics, political and computer science, and ecology by providing a repository of lecture notes and tests for courses using…

Drought-induced reduction in global terrestrial net primary production from 2000 through 2009.

Science.gov (United States)

Zhao, Maosheng; Running, Steven W

2010-08-20

Terrestrial net primary production (NPP) quantifies the amount of atmospheric carbon fixed by plants and accumulated as biomass. Previous studies have shown that climate constraints were relaxing with increasing temperature and solar radiation, allowing an upward trend in NPP from 1982 through 1999. The past decade (2000 to 2009) has been the warmest since instrumental measurements began, which could imply continued increases in NPP; however, our estimates suggest a reduction in the global NPP of 0.55 petagrams of carbon. Large-scale droughts have reduced regional NPP, and a drying trend in the Southern Hemisphere has decreased NPP in that area, counteracting the increased NPP over the Northern Hemisphere. A continued decline in NPP would not only weaken the terrestrial carbon sink, but it would also intensify future competition between food demand and proposed biofuel production.

Estimating Net Primary Productivity Using Satellite and Ancillary Data

Science.gov (United States)

Choudhury, Bhaskar J.

2002-01-01

The net primary productivity (C) or the annual rate of carbon accumulation per unit ground area by terrestrial plant communities is the difference of gross photosynthesis (A(sub g)) and respiration (R) per unit ground area. Available field observations show that R is a large and variable fraction of A(sub g), although it is generally recognized that there are considerable difficulties in determining these fluxes, and thus pose challenge in assessing the accuracy. Further uncertainties arise in extrapolating field measurements (which are acquired over a hectare or so area) to regional scale. Here, an approach is presented for determining these fluxes using satellite and ancillary data to be representative of regional scale and allow assessment of interannual variation. A, has been expressed as the product of radiation use efficiency for gross photosynthesis by an unstressed canopy and intercepted photosynthetically active radiation, which is then adjusted for stresses due to soil water shortage and temperature away from optimum. R has been calculated as the sum of growth and maintenance components (respectively, R(sub g) and R(sub m)).The R(sub m) has been determined from nitrogen content of plant tissue per unit ground area, while R(sub g) has been obtained as a fraction of the difference of A(sub g) and R(sub m). Results for five consecutive years (1986-1990) are presented for the Amazon-Tocontins, Mississippi, and Ob River basins.

Net primary productivity distribution in the BOREAS region from a process model using satellite and surface data

Science.gov (United States)

Liu, J.; Chen, J. M.; Cihlar, J.; Chen, W.

1999-11-01

The purpose of this paper is to upscale tower measurements of net primary productivity (NPP) to the Boreal Ecosystem-Atmosphere Study (BOREAS) study region by means of remote sensing and modeling. The Boreal Ecosystem Productivity Simulator (BEPS) with a new daily canopy photosynthesis model was first tested in one coniferous and one deciduous site. The simultaneous CO2 flux measurements above and below the tree canopy made it possible to isolate daily net primary productivity of the tree canopy for model validation. Soil water holding capacity and gridded daily meteorological data for the region were used as inputs to BEPS, in addition to 1 km resolution land cover and leaf area index (LAI) maps derived from the advanced very high resolution radiometer (AVHRR) data. NPP statistics for the various cover types in the BOREAS region and in the southern study area (SSA) and the northern study area (NSA) are presented. Strong dependence of NPP on LAI was found for the three major cover types: coniferous forest, deciduous forest and cropland. Since BEPS can compute total photosynthetically active radiation absorbed by the canopy in each pixel, light use efficiencies for NPP and gross primary productivity could also be analyzed. From the model results, the following area-averaged statistics were obtained for 1994: (1) mean NPP for the BOREAS region of 217 g C m-2 yr-1; (2) mean NPP of forests (excluding burnt areas in the region) equal to 234 g C m-2 yr-1; (3) mean NPP for the SSA and the NSA of 297 and 238 g C m-2 yr-1, respectively; and (4) mean light use efficiency for NPP equal to 0.40, 0.20, and 0.33 g C (MJ APAR)-1 for deciduous forest, coniferous forest, and crops, respectively.

Optimum Temperatures for Net Primary Productivity of Three Tropical Seagrass Species

OpenAIRE

Collier, Catherine J.; Ow, Yan X.; Langlois, Lucas; Uthicke, Sven; Johansson, Charlotte L.; O'Brien, Katherine R.; Hrebien, Victoria; Adams, Matthew P.

2017-01-01

Rising sea water temperature will play a significant role in responses of the world's seagrass meadows to climate change. In this study, we investigated seasonal and latitudinal variation (spanning more than 1,500 km) in seagrass productivity, and the optimum temperatures at which maximum photosynthesis and net productivity (for the leaf and the whole plant) occurs, for three seagrass species (Cymodocea serrulata, Halodule uninervis, and Zostera muelleri). To obtain whole plant net production...

A below-ground herbivore shapes root defensive chemistry in natural plant populations

OpenAIRE

Huber, Meret; Bont, Zoe; Fricke, Julia; Brillatz, Th?o; Aziz, Zohra; Gershenzon, Jonathan; Erb, Matthias

2016-01-01

Plants display extensive intraspecific variation in secondary metabolites. However, the selective forces shaping this diversity remain often unknown, especially below ground. Using Taraxacum officinale and its major native insect root herbivore Melolontha melolontha, we tested whether below-ground herbivores drive intraspecific variation in root secondary metabolites. We found that high M. melolontha infestation levels over recent decades are associated with high concentrations of major root ...

Picturing Adoption of Below-Ground Biodiversity Technologies among Smallholder Farmers around Mabira Forest, Uganda

Directory of Open Access Journals (Sweden)

Isabirye, BE.

2010-01-01

Full Text Available Faced with a multitude of soil and water amendment technologies, farmers have the task of choosing the technologies to adopt for ensuring subsistence and income sustainability. In 2008, a study to characterize the farmers was conducted around Mabira Forest, to assess the adoption of soil technologies fostering Belowground Biodiversity (BGBD. Eighty-four households (38 participating and 46 non-participants from four villages were randomly selected and interviewed. Results showed that the adoption pattern was significantly driven by farm size, labor, household size, age and wealth status of the house. Also important were farm location, gender of household head, primary occupation, soil and water conservation technologies training, land tenure, and social capital. For the few current adopters, there was a perceived increase in labor demand but overall productivity was higher, partly resulting from increased crop productivity due to soil fertility enhancement and soil structure modification. It is therefore concluded that, around Mabira forest, BGBD technologies will be adopted by farming households with sufficient land, labor and social capital.

Interactive effects of above- and belowground herbivory and plant competition on plant growth and defence

NARCIS (Netherlands)

Jing, Y.; Raaijmakers, C.; Kostenko, O.; Kos, M.; Mulder, P.P.J.; Bezemer, T.M.

2015-01-01

Competition and herbivory are two major factors that can influence plant growth and plant defence. Although these two factors are often studied separately, they do not operate independently. We examined how aboveground herbivory by beet armyworm larvae (Spodoptera exigua) and belowground herbivory

Assessing the impact of the urbanization process on net primary productivity in China in 1989–2000

International Nuclear Information System (INIS)

Tian, Guangjin; Qiao, Zhi

2014-01-01

Urban development affects the material circulation and energy flow of ecosystems, thereby affecting the Net Primary Productivity (NPP). The loss of NPP due to urban expansion was calculated integrating GLO-PEM with remote sensing and GIS techniques in China during the period of 1989–2000. Using urban expansion and the mean NPP for the different land use types in the fourteen regions, the total loss of NPP was calculated as 0.95 Tg C, which accounted for 0.03% of the national NPP of 1989. The total loss of NPP due to the transformation from cropland to urban land accounted for 91.93%, followed by forest (7.17%) and grassland (0.69%). However, the conversion from unused land, industrial and construction land, and water bodies to urban land resulted in an increase in the NPP. The regions locating in eastern China and middle China had large reductions in the total NPP due to urban expansion. -- Highlights: • This paper assesses the impact of urbanization process on net primary productivity in China. • TM images were interpreted to obtain the extent and spatial distribution of urban development. • Using mean NPP for different land uses, we calculated total loss of NPP was 0.949447 Tg C in China. • The total loss of NPP owing to the transformation from cropland to urban land accounted for 91.93%. -- The loss of NPP due to urban expansion was calculated as 0.95 Tg C in China in 1989–2000, which accounted for 0.03% of the national NPP of 1989

Contribution of above- and below-ground plant traits to the structure and function of grassland soil microbial communities.

Science.gov (United States)

Legay, N; Baxendale, C; Grigulis, K; Krainer, U; Kastl, E; Schloter, M; Bardgett, R D; Arnoldi, C; Bahn, M; Dumont, M; Poly, F; Pommier, T; Clément, J C; Lavorel, S

2014-10-01

Abiotic properties of soil are known to be major drivers of the microbial community within it. Our understanding of how soil microbial properties are related to the functional structure and diversity of plant communities, however, is limited and largely restricted to above-ground plant traits, with the role of below-ground traits being poorly understood. This study investigated the relative contributions of soil abiotic properties and plant traits, both above-ground and below-ground, to variations in microbial processes involved in grassland nitrogen turnover. In mountain grasslands distributed across three European sites, a correlative approach was used to examine the role of a large range of plant functional traits and soil abiotic factors on microbial variables, including gene abundance of nitrifiers and denitrifiers and their potential activities. Direct effects of soil abiotic parameters were found to have the most significant influence on the microbial groups investigated. Indirect pathways via plant functional traits contributed substantially to explaining the relative abundance of fungi and bacteria and gene abundances of the investigated microbial communities, while they explained little of the variance in microbial activities. Gene abundances of nitrifiers and denitrifiers were most strongly related to below-ground plant traits, suggesting that they were the most relevant traits for explaining variation in community structure and abundances of soil microbes involved in nitrification and denitrification. The results suggest that consideration of plant traits, and especially below-ground traits, increases our ability to describe variation in the abundances and the functional characteristics of microbial communities in grassland soils. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Net ecosystem productivity and carbon dynamics of the traditionally managed Imperata grasslands of North East India.

Science.gov (United States)

Pathak, Karabi; Malhi, Yadvinder; Sileshi, G W; Das, Ashesh Kumar; Nath, Arun Jyoti

2018-09-01

There have been few comprehensive descriptions of how fire management and harvesting affect the carbon dynamics of grasslands. Grasslands dominated by the invasive weed Imperata cylindrica are considered as environmental threats causing low land productivity throughout the moist tropical regions in Asia. Imperata grasslands in North East India are unique in that they are traditionally managed and culturally important in the rural landscapes. Given the importance of fire in the management of Imperata grassland, we aimed to assess (i) the seasonal pattern of biomass production, (ii) the eventual pathways for the produced biomass, partitioned between in situ decomposition, harvesting and combustion, and (iii) the effect of customary fire management on the ecosystem carbon cycle. Comparatively high biomass production was recorded during pre-monsoon (154 g m -2  month -1 ) and monsoon (214 g m -2  month -1 ) compared to the post-monsoon (91 g m -2  month -1 ) season, and this is attributed to nutrient return into the soil immediately after fire in February. Post fire effects might have killed roots and rhizomes leading to high belowground litter production 30-35 g m -2 during March to August. High autotrophic respiration was recorded during March-July, which was related to high belowground biomass production (35-70 g m -2 ) during that time. Burning removed all the surface litter in March and this appeared to hinder surface decomposition and result in low heterotrophic respiration. Annual total biomass carbon production was estimated at 886 g C m -2 . Annual harvest of biomass (estimated at 577 g C m -2 ) was the major pathway for carbon fluxes from the system. Net ecosystem production (NEP) of Imperata grassland was estimated at 91 g C m -2  yr -1 indicating that these grasslands are a net sink of CO 2 , although this is greatly influenced by weather and fire management. Crown Copyright © 2018. Published by Elsevier B

Root herbivory indirectly affects above- and below-ground community members and directly reduces plant performance

NARCIS (Netherlands)

Barber, N.A.; Milano, N.J.; Kiers, E.T.; Theis, N.; Bartolo, V.; Hazzard, R.V.; Adler, L.S.

2015-01-01

There is a widespread recognition that above- and below-ground organisms are linked through their interactions with host plants that span terrestrial subsystems. In addition to direct effects on plants, soil organisms such as root herbivores can indirectly alter interactions between plants and other

Interactions between above- and belowground biota: importance for small-scale vegetation mosaics in a grassland ecosystem

NARCIS (Netherlands)

Blomqvist, M.M.; Olff, H.; Blaauw, M.B.; Bongers, T.; Van der Putten, W.H.

2000-01-01

Grasslands are often characterised by small-scale mosaics in plant community composition that contribute to their diversity. Although above- and belowground biota can both cause such mosaics, few studies have addressed their interacting effects. We studied multi-trophic interactions between

Interactions between above- and belowground biota : importance for small-scale vegetation mosaics in a grassland ecosystem

NARCIS (Netherlands)

Blomqvist, N.M.; Olff, H.; Blaauw, M.B.; Bongers, T.; Putten, van der W.H.

2000-01-01

Grasslands are often characterised by small-scale mosaics in plant community composition that contribute to their diversity. Although above- and belowground biota can both cause such mosaics, few studies have addressed their interacting effects. We studied multi-trophic interactions between

Root interactions in a diverse grassland : the role of root traits in belowground productivity and decomposition

NARCIS (Netherlands)

Oram, Natalie J.

2018-01-01

Background Plant diversity influences ecosystem functioning. A positive relation between plant diversity and productivity above- and belowground has been established. Aboveground, this effect has been shown to be due to complementarity effects, interactions between species in a mixture

Water consumption in artificial desert oasis based on net primary productivity

Institute of Scientific and Technical Information of China (English)

无

2010-01-01

Analysis of the water consumption is the basis for water allocation in oasis. However, the method of estimating oasis water consumption remains a great challenge. Based on net primary productivity (NPP) and the transpiration coefficient, a vegetation water consumption model was developed to estimate the water consumption in desert oasis in ERDAS environment. Our results demonstrated that the ecosystem in the middle reaches of the Heihe oasis consumed water of 18.41×108-21.9×108 m3 for irrigation. Without taking precipitation into account, the water consumption in farmland accounted for 77.1%-77.8% (or about 13.97×108-16.84×108 m3) of the oasis vegetation water consumption and in the farmland protection system accounting for 22%. The growing period precipitation in desert environments is about 7.02×108 m3, and the total annual precipitation is about 8.29×108 m3. The modeled water consumption of desert vegetation, however, is about 4.57×108 m3, equivalent to only 65% of the growing period precipitation or 55% of the total annual precipitation. The modeled value equals to the cumulative precipitation of greater than 5 mm, which is defined as the effective precipitation in arid desert.

Net primary productivity collected from New Horizon in Gulf of California and North Pacific Ocean from 2004-07-14 to 2008-08-06 (NCEI Accession 0130076)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Net primary productivity determined from 13C-labeled in situ incubations. Water collected via Niskin bottle was incubated with labeled bicarbonate for 24 hours at...

Total belowground carbon flux in subalpine forests is related to leaf area index, soil nitrogen, and tree height

Science.gov (United States)

Berryman, Erin Michele; Ryan, Michael G.; Bradford, John B.; Hawbaker, Todd J.; Birdsey, R.

2016-01-01

In forests, total belowground carbon (C) flux (TBCF) is a large component of the C budget and represents a critical pathway for delivery of plant C to soil. Reducing uncertainty around regional estimates of forest C cycling may be aided by incorporating knowledge of controls over soil respiration and TBCF. Photosynthesis, and presumably TBCF, declines with advancing tree size and age, and photosynthesis increases yet C partitioning to TBCF decreases in response to high soil fertility. We hypothesized that these causal relationships would result in predictable patterns of TBCF, and partitioning of C to TBCF, with natural variability in leaf area index (LAI), soil nitrogen (N), and tree height in subalpine forests in the Rocky Mountains, USA. Using three consecutive years of soil respiration data collected from 22 0.38-ha locations across three 1-km2 subalpine forested landscapes, we tested three hypotheses: (1) annual soil respiration and TBCF will show a hump-shaped relationship with LAI; (2) variability in TBCF unexplained by LAI will be related to soil nitrogen (N); and (3) partitioning of C to TBCF (relative to woody growth) will decline with increasing soil N and tree height. We found partial support for Hypothesis 1 and full support for Hypotheses 2 and 3. TBCF, but not soil respiration, was explained by LAI and soil N patterns (r2 = 0.49), and the ratio of annual TBCF to TBCF plus aboveground net primary productivity (ANPP) was related to soil N and tree height (r2 = 0.72). Thus, forest C partitioning to TBCF can vary even within the same forest type and region, and approaches that assume a constant fraction of TBCF relative to ANPP may be missing some of this variability. These relationships can aid with estimates of forest soil respiration and TBCF across landscapes, using spatially explicit forest data such as national inventories or remotely sensed data products.

Evaluation of DementiaNet, a network-based primary care innovation for community-dwelling patients with dementia: protocol for a longitudinal mixed methods multiple case study

NARCIS (Netherlands)

Richters, A.; Nieuwboer, M.S.; Perry, M.; Olde Rikkert, M.G.M.; Melis, R.J.F.; Marck, M.A. van der

2017-01-01

INTRODUCTION: Primary healthcare professionals will increasingly be required to manage and optimise their treatment for patients with dementia. With DementiaNet, we aim to reduce the burden of dementia on healthcare services and society through implementation and facilitation of integrated

Alteration of belowground carbon dynamics by nitrogen addition in southern California mixed conifer forests

Science.gov (United States)

N.S. Nowinski; S.E. Trumbore; G. Jimenez; M.E. Fenn

2009-01-01

Nitrogen deposition rates in southern California are the highest in North America and have had substantial effects on ecosystem functioning. We document changes in the belowground C cycle near ponderosa pine trees experiencing experimental nitrogen (N) addition (50 and 150 kg N ha−1 a−1 as slow release urea since 1997) at two end‐member...

Belowground plant biomass of mountain grassland affected by regular and manipulated rainfall in 2006 and 2007

Czech Academy of Sciences Publication Activity Database

Fiala, Karel; Tůma, Ivan

2008-01-01

Roč. 1, č. 1 (2008), s. 19-22 ISSN 1803-2451 R&D Projects: GA ČR(CZ) GA526/06/0556 Institutional research plan: CEZ:AV0Z60050516 Keywords : root increments * total belowground biomass * manipulated rainfall Subject RIV: EF - Botanics

Estimation Terrestrial Net Primary Productivity Based on CASA Model: a Case Study in Minnan Urban Agglomeration, China

International Nuclear Information System (INIS)

Hua, L Z; Liu, H; Zhang, X L; Zheng, Y; Man, W; Yin, K

2014-01-01

Net Primary Productivity (NPP) is a key component of the terrestrial carbon cycle. The research of net primary productivity will help in understanding the amount of carbon fixed by terrestrial vegetation and its influencing factors. Model simulation is considered as a cost-effective and time-efficient method for the estimation of regional and global NPP. In the paper, a terrestrial biosphere model, CASA (Carnegie Ames Stanford Approach), was applied to estimate monthly NPP in Minnan urban agglomeration (i.e. Xiamen, Zhangzhou and Quanzhou cities) of Fujian province, China, in 2009 and 2010, by incorporating satellite observation of SPOT Vegetation NDVI data together with other climatic parameters and landuse map. The model estimates average annual terrestrial NPP of Minnan area as 16.3 million Mg C. NPP decreased from southwest to the northeast. The higher NPP values exceeding 720 gC·m − 2 ·a −1 showed in North Zhangzhou city and lower values under 500 gC·m − 2 ·a −1 showed in the some areas of northeast Quanzhou city. Seasonal variations of NPP were large. It was about 45% of the total annual NPP in the three months in summer, and the NPP values were very low in winter. From 2009 to 2010, the value of annual NPP showed a slightly decrease trend, approximately 7.8% because the annual temperature for 2010 decline 13.6% compared with 2009 in despite of an increase in rainfall of about 34.3%. The results indicate that temperature was a main limiting factor on vegetation growth, but water is not a limiting factor in the rainy area

Cowpea N rhizodeposition and its below-ground transfer to a co-existing and to a subsequent millet crop on a sandy soil of the Sudano-Sahelian eco-zone

DEFF Research Database (Denmark)

Laberge, Guillaume; Haussmann, Bettina I.G.; Ambus, Per

2011-01-01

Nitrogen (N) rhizodeposition by cowpea (Vigna unguiculata (L.) Walp) is potentially a large N source in cropping systems of Sub-Saharan Africa. A field experiment was conducted to measure cowpea N rhizodeposition under the conditions of the Sudano-Sahelian zone using direct 15N labelling techniques...... to trace the amount of deposition and its transfer to associated and subsequent crops. Half of the total cowpea crop N was located below-ground at plant maturity, which exceeded 20 kg N ha−1 when intercropped with millet. Only 15% of the below-ground cowpea N was recovered in roots, while 85% was found...... in the rhizodeposited pools. The experiment demonstrated that direct below-ground N transfer occurred from cowpea to millet in intercrop at a rate of 2 kg N ha−1 over the growing season. Forty percent of the 25 kg below-ground N that the cowpea crop left at harvest were identifiable in the top 0.30 m soil...

Tropospheric O3 compromises net primary production in young stands of trembling aspen, paper birch and sugar maple in response to elevated atmospheric CO2

Science.gov (United States)

John S. King; Mark E. Kubiske; Kurt S. Pregitzer; George R. Hendrey; Evan P. McDonald; Christian P. Giardina; Vanessa S. Quinn; David F. Karnosky

2005-01-01

Concentrations of atmospheric CO2 and tropospheric ozone (O3) are rising concurrently in the atmosphere, with potentially antagonistic effects on forest net primary production (NPP) and implications for terrestrial carbon sequestration. Using free-air CO2 enrichment (FACE) technology, we exposed north...

Markets, voucher subsidies and free nets combine to achieve high bed net coverage in rural Tanzania

Directory of Open Access Journals (Sweden)

Gerrets Rene PM

2008-06-01

Full Text Available Abstract Background Tanzania has a well-developed network of commercial ITN retailers. In 2004, the government introduced a voucher subsidy for pregnant women and, in mid 2005, helped distribute free nets to under-fives in small number of districts, including Rufiji on the southern coast, during a child health campaign. Contributions of these multiple insecticide-treated net delivery strategies existing at the same time and place to coverage in a poor rural community were assessed. Methods Cross-sectional household survey in 6,331 members of randomly selected 1,752 households of 31 rural villages of Demographic Surveillance System in Rufiji district, Southern Tanzania was conducted in 2006. A questionnaire was administered to every consenting respondent about net use, treatment status and delivery mechanism. Findings Net use was 62.7% overall, 87.2% amongst infants (0 to1 year, 81.8% amongst young children (>1 to 5 years, 54.5% amongst older children (6 to 15 years and 59.6% amongst adults (>15 years. 30.2% of all nets had been treated six months prior to interview. The biggest source of nets used by infants was purchase from the private sector with a voucher subsidy (41.8%. Half of nets used by young children (50.0% and over a third of those used by older children (37.2% were obtained free of charge through the vaccination campaign. The largest source of nets amongst the population overall was commercial purchase (45.1% use and was the primary means for protecting adults (60.2% use. All delivery mechanisms, especially sale of nets at full market price, under-served the poorest but no difference in equity was observed between voucher-subsidized and freely distributed nets. Conclusion All three delivery strategies enabled a poor rural community to achieve net coverage high enough to yield both personal and community level protection for the entire population. Each of them reached their relevant target group and free nets only temporarily

Daily variation in net primary production and net calcification in coral reef communities exposed to elevated pCO2

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S. Comeau

2017-07-01

Full Text Available The threat represented by ocean acidification (OA for coral reefs has received considerable attention because of the sensitivity of calcifiers to changing seawater carbonate chemistry. However, most studies have focused on the organismic response of calcification to OA, and only a few have addressed community-level effects, or investigated parameters other than calcification, such as photosynthesis. Light (photosynthetically active radiation, PAR is a driver of biological processes on coral reefs, and the possibility that these processes might be perturbed by OA has important implications for community function. Here we investigate how CO2 enrichment affects the relationships between PAR and community net O2 production (Pnet, and between PAR and community net calcification (Gnet, using experiments on three coral communities constructed to match (i the back reef of Mo'orea, French Polynesia, (ii the fore reef of Mo'orea, and (iii the back reef of O'ahu, Hawaii. The results were used to test the hypothesis that OA affects the relationship between Pnet and Gnet. For the three communities tested, pCO2 did not affect the Pnet–PAR relationship, but it affected the intercept of the hyperbolic tangent curve fitting the Gnet–PAR relationship for both reef communities in Mo'orea (but not in O'ahu. For the three communities, the slopes of the linear relationships between Pnet and Gnet were not affected by OA, although the intercepts were depressed by the inhibitory effect of high pCO2 on Gnet. Our result indicates that OA can modify the balance between net calcification and net photosynthesis of reef communities by depressing community calcification, but without affecting community photosynthesis.

Influence of ozone pollution and climate variability on net primary productivity and carbon storage in China's grassland ecosystems from 1961 to 2000

International Nuclear Information System (INIS)

Ren Wei; Tian Hanqin; Chen Guangsheng; Liu Mingliang; Zhang Chi; Chappelka, Arthur H.; Pan Shufen

2007-01-01

Our simulations with the Dynamic Land Ecosystem Model (DLEM) indicate that the combined effect of ozone, climate, carbon dioxide and land use have caused China's grasslands to act as a weak carbon sink during 1961-2000. This combined effect on national grassland net primary productivity (NPP) and carbon storage was small, but changes in annual NPP and total carbon storage across China's grasslands showed substantial spatial variation, with the maximum total carbon uptake reduction of more than 400 g m -2 in some places of northeastern China. The grasslands in the central northeastern China were more sensitive and vulnerable to elevated ozone pollution than other regions. The combined effect excluding ozone could potentially lead to an increase of 14 Tg C in annual NPP and 0.11 Pg C in total carbon storage for the same time period. This implies that improvement in air quality could significantly increase productivity and carbon storage in China's grassland ecosystems. - Net primary productivity and carbon storage across China's grassland in the late half of the 20th century have been assessed by using the Dynamic Land Ecosystem Model

Short- and longterm impacts of Acacia longifolia invasion on belowground processes of a Mediterranean coastal dune ecosystem

DEFF Research Database (Denmark)

Marchante, Elizabete; Kjøller, Annelise; Struwe, Sten

2008-01-01

to new areas, displacing the native vegetation. These invaded ecosystems contrast with the native dune ecosystems that are typically dominated by herb and shrub communities. This study characterizes belowground changes to the native environment as a result of recent (20 y...

Effects of topography on simulated net primary productivity at landscape scale.

Science.gov (United States)

Chen, X F; Chen, J M; An, S Q; Ju, W M

2007-11-01

Local topography significantly affects spatial variations of climatic variables and soil water movement in complex terrain. Therefore, the distribution and productivity of ecosystems are closely linked to topography. Using a coupled terrestrial carbon and hydrological model (BEPS-TerrainLab model), the topographic effects on the net primary productivity (NPP) are analyzed through four modelling experiments for a 5700 km(2) area in Baohe River basin, Shaanxi Province, northwest of China. The model was able to capture 81% of the variability in NPP estimated from tree rings, with a mean relative error of 3.1%. The average NPP in 2003 for the study area was 741 gCm(-2)yr(-1) from a model run including topographic effects on the distributions of climate variables and lateral flow of ground water. Topography has considerable effect on NPP, which peaks near 1350 m above the sea level. An elevation increase of 100 m above this level reduces the average annual NPP by about 25 gCm(-2). The terrain aspect gives rise to a NPP change of 5% for forests located below 1900 m as a result of its influence on incident solar radiation. For the whole study area, a simulation totally excluding topographic effects on the distributions of climatic variables and ground water movement overestimated the average NPP by 5%.

Arbuscular mycorrhizal fungi alter above- and below-ground chemical defense expression differentially among Asclepias species

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Rachel L Vannette

2013-09-01

Full Text Available Belowground symbionts of plants can have substantial influence on plant growth and nutrition. Recent work demonstrates that mycorrhizal fungi can affect plant resistance to herbivory and the performance of above and belowground herbivores. Although these examples emerge from diverse systems, it is unclear if plant species that express similar defensive traits respond similarly to fungal colonization, but comparative work may inform this question. To examine the effects of arbuscular mycorrhizal fungi (AMF on the expression of chemical resistance, we inoculated 8 species of Asclepias (milkweed--which all produce toxic cardenolides--with a community of AMF. We quantified plant biomass, foliar and root cardenolide concentration and composition, and assessed evidence for a growth-defense tradeoff in the presence and absence of AMF. As expected, total foliar and root cardenolide concentration varied among milkweed species. Importantly, the effect of mycorrhizal fungi on total foliar cardenolide concentration also varied among milkweed species, with foliar cardenolides increasing or decreasing, depending on the plant species. We detected a phylogenetic signal to this variation; AMF fungi reduced foliar cardenolide concentrations to a greater extent in the clade including A. curassavica than in the clade including A. syriaca. Moreover, AMF inoculation shifted the composition of cardenolides in above- and below-ground plant tissues in a species-specific fashion. Mycorrhizal inoculation changed the relative distribution of cardenolides between root and shoot tissue in a species-specific fashion, but did not affect cardenolide diversity or polarity. Finally, a tradeoff between plant growth and defense in non-mycorrhizal plants was mitigated completely by AMF inoculation. Overall, we conclude that the effects of AMF inoculation on the expression of chemical resistance can vary among congeneric plant species, and ameliorate tradeoffs between growth and

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

Science.gov (United States)

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

2017-12-01

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

Estimating Net Primary Production of Swedish Forest Landscapes by Combining Mechanistic Modeling and Remote Sensing

DEFF Research Database (Denmark)

Tagesson, Håkan Torbern; Smith, Benjamin; Løfgren, Anders

2009-01-01

and the Beer-Lambert law. LAI estimates were compared with satellite-extrapolated field estimates of LAI, and the results were generally acceptable. NPP estimates directly from the dynamic vegetation model and estimates obtained by combining the model estimates with remote sensing information were, on average......The aim of this study was to investigate a combination of satellite images of leaf area index (LAI) with processbased vegetation modeling for the accurate assessment of the carbon balances of Swedish forest ecosystems at the scale of a landscape. Monthly climatologic data were used as inputs...... in a dynamic vegetation model, the Lund Potsdam Jena-General Ecosystem Simulator. Model estimates of net primary production (NPP) and the fraction of absorbed photosynthetic active radiation were constrained by combining them with satellite-based LAI images using a general light use efficiency (LUE) model...

VARIABILITY IN NET PRIMARY PRODUCTION AND CARBON STORAGE IN BIOMASS ACROSS OREGON FORESTS - AN ASSESSMENT INTEGRATING DATA FROM FOREST INVENTORIES, INTENSIVE SITES, AND REMOTE SENSING. (R828309)

Science.gov (United States)

We used a combination of data from USDA Forest Service inventories, intensivechronosequences, extensive sites, and satellite remote sensing, to estimate biomassand net primary production (NPP) for the forested region of western Oregon. Thestudy area was divided int...

Epiphyte-cover on seagrass (Zostera marina L. leaves impedes plant performance and radial O2 loss from the below-ground tissue

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Kasper Elgetti Brodersen

2015-08-01

Full Text Available The O2 budget of seagrasses is a complex interaction between several sources and sinks, which is strongly regulated by light availability and mass transfer over the diffusive boundary layer (DBL surrounding the plant. Epiphyte growth on leaves may thus strongly affect the O2 availability of the seagrass plant and its capability to aerate its rhizosphere as a defence against plant toxins.We used electrochemical and fiber-optic microsensors to quantify the O2 flux, DBL and light microclimate around leaves with and without filamentous algal epiphytes. We also quantified the below-ground radial O2 loss from roots (~1 mm from the root-apex to elucidate how this below-ground oxic microzone was affected by the presence of epiphytes.Epiphyte-cover on seagrass leaves (~21% areal cover resulted in reduced light quality and quantity for photosynthesis, thus leading to reduced plant fitness. A ~4 times thicker diffusive boundary layer around leaves with epiphyte-cover impeded gas (and nutrient exchange with the surrounding water-column and thus the amount of O2 passively diffusing into the leaves in darkness. During light exposure of the leaves, radial oxygen loss from the below-ground tissue was ~2 times higher from plants without epiphyte-cover. In contrast, no O2 was detectable at the surface of the root-cap tissue of plants with epiphyte-cover during darkness, leaving the plants more susceptible to sulphide intrusion.Epiphyte growth on seagrass leaves thus negatively affects the light climate and O2 uptake in darkness, hampering the plants performance and thereby reducing the oxidation capability of its below-ground tissue.

Estimating Net Primary Productivity Beneath Snowpack Using Snowpack Radiative Transfer Modeling and Global Satellite Data

Science.gov (United States)

Barber, D. E.; Peterson, M. C.

2002-05-01

Sufficient photosynthetically active radiation (PAR) penetrates snow for plants to grow beneath snowpack during late winter or early spring in tundra ecosystems. During the spring in this ecosystem, the snowpack creates an environment with higher humidity and less variable and milder temperatures than on the snow-free land. Under these conditions, the amount of PAR available is likely to be the limiting factor for plant growth. Current methods for determining net primary productivity (NPP) of tundra ecosystems do not account for this plant growth beneath snowpack, apparently resulting in underestimating plant production there. We are currently in the process of estimating the magnitude of this early growth beneath snow for tundra ecosystems. Our method includes a radiative transfer model that simulates diffuse and direct PAR penetrating snowpack based on downwelling PAR values and snow depth data from global satellite databases. These PAR levels are convolved with plant growth for vegetation that thrives beneath snowpacks, such as lichen. We expect to present the net primary production for Cladonia species (a common Arctic lichen) that has the capability of photosynthesizing at low temperatures beneath snowpack. This method may also be used to study photosynthesis beneath snowpacks in other hardy plants. Lichens are used here as they are common in snow-covered regions, flourish under snowpack, and provide an important food source for tundra herbivores (e.g. caribou). In addition, lichens are common in arctic-alpine environments and our results can be applied to these ecosystems as well. Finally, the NPP of lichen beneath snowpack is relatively well understood compared to other plants, making it ideal vegetation for this first effort at estimating the potential importance of photosynthesis at large scales. We are examining other candidate plants for their photosynthetic potential beneath snowpack at this time; however, little research has been done on this topic. We

Availability and temporal heterogeneity of water supply affect the vertical distribution and mortality of a belowground herbivore and consequently plant growth.

Science.gov (United States)

Tsunoda, Tomonori; Kachi, Naoki; Suzuki, Jun-Ichirou

2014-01-01

We examined how the volume and temporal heterogeneity of water supply changed the vertical distribution and mortality of a belowground herbivore, and consequently affected plant biomass. Plantago lanceolata (Plantaginaceae) seedlings were grown at one per pot under different combinations of water volume (large or small volume) and heterogeneity (homogeneous water conditions, watered every day; heterogeneous conditions, watered every 4 days) in the presence or absence of a larva of the belowground herbivorous insect, Anomala cuprea (Coleoptera: Scarabaeidae). The larva was confined in different vertical distributions to top feeding zone (top treatment), middle feeding zone (middle treatment), or bottom feeding zone (bottom treatment); alternatively no larva was introduced (control treatment) or larval movement was not confined (free treatment). Three-way interaction between water volume, heterogeneity, and the herbivore significantly affected plant biomass. With a large water volume, plant biomass was lower in free treatment than in control treatment regardless of heterogeneity. Plant biomass in free treatment was as low as in top treatment. With a small water volume and in free treatment, plant biomass was low (similar to that under top treatment) under homogeneous water conditions but high under heterogeneous ones (similar to that under middle or bottom treatment). Therefore, there was little effect of belowground herbivory on plant growth under heterogeneous water conditions. In other watering regimes, herbivores would be distributed in the shallow soil and reduced root biomass. Herbivore mortality was high with homogeneous application of a large volume or heterogeneous application of a small water volume. Under the large water volume, plant biomass was high in pots in which the herbivore had died. Thus, the combinations of water volume and heterogeneity affected plant growth via the change of a belowground herbivore.

Primary hyperaldosteronism in cats: expanding the diagnostic net

NARCIS (Netherlands)

Djajadiningrat-Laanen, S.C.

2014-01-01

Primary hyperaldosteronism or low-renin hyperaldosteronism in cats is characterized by inappropriately high aldosterone secretion from one or both adrenal glands, with systemic arterial hypertension and hypokalemia as leading clinical manifestations. In this thesis, non-tumorous primary

Simulation of Net Primary Productivity in Mongolia Using CASA Model, During 2000-2004

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Narangarav Dugarsuren

2016-12-01

Full Text Available Vegetation net primary productivity (NPP is always used as an indicator of carbon cycling in terrestrial ecosystems at landscape and regional scales. Based on the CASA model, we analyzed the spatiotemporal pattern of growing season NPP from 2000 to 2004 using MODIS/NDVI and its relationship with precipitation. The result shows that the annual NPP in Mongolia has a tendency to slightly decrease from 61.13 in 2000 to 60 gC/m2 /yr in 2004, with an annual mean decrement of -0.259 gC/ m2 /yr. However, annual and inter-annual NPP trends showed spatial and temporal heterogeneity. NPP in forest and grassland has decreased with an average annual decrement of -1.03 (r2=0.262 and -0.49 (r2=0.324, meanwhile NPP in desert steppe and desert has increased with the annual average increment of 0.4327 (r2=0.322 and 0.2401 (r2=0.283, respectively. The correlation coeffi cient showed that mean growing season NPP in grassland and desert steppe were closely correlated with precipitation than forest and desert.

Nitrogen mediates above-ground effects of ozone but not below-ground effects in a rhizomatous sedge

International Nuclear Information System (INIS)

Jones, M.L.M.; Hodges, G.; Mills, G.

2010-01-01

Ozone and atmospheric nitrogen are co-occurring pollutants with adverse effects on natural grassland vegetation. Plants of the rhizomatous sedge Carex arenaria were exposed to four ozone regimes representing increasing background concentrations (background-peak): 10-30, 35-55, 60-80 and 85-105 ppb ozone at two nitrogen levels: 12 and 100 kg N ha -1 yr -1 . Ozone increased the number and proportion of senesced leaves, but not overall leaf number. There was a clear nitrogen x ozone interaction with high nitrogen reducing proportional senescence in each treatment and increasing the ozone dose (AOT40) at which enhanced senescence occurred. Ozone reduced total biomass due to significant effects on root biomass. There were no interactive effects on shoot:root ratio. Rhizome tissue N content was increased by both nitrogen and ozone. Results suggest that nitrogen mediates above-ground impacts of ozone but not impacts on below-ground resource translocation. This may lead to complex interactive effects between the two pollutants on natural vegetation. - Nitrogen alters threshold of ozone-induced senescence, but not below-ground resource allocation.

Short-term belowground responses to thinning and burning treatments in southwestern ponderosa pine forests of the USA

Science.gov (United States)

Steven T. Overby; Stephen C. Hart

2016-01-01

Microbial-mediated decomposition and nutrient mineralization are major drivers of forest productivity. As landscape-scale fuel reduction treatments are being implemented throughout the fire-prone western United States of America, it is important to evaluate operationally how these wildfire mitigation treatments alter belowground processes. We quantified these important...

Partitioning of net carbon dioxide flux measured by automatic transparent chamber

Science.gov (United States)

Dyukarev, EA

2018-03-01

Mathematical model was developed for describing carbon dioxide fluxes at open sedge-sphagnum fen during growing season. The model was calibrated using the results of observations from automatic transparent chamber and it allows us to estimate autotrophic, heterotrophic and ecosystem respiration fluxes, gross and net primary vegetation production, and the net carbon balance.

Early root overproduction not triggered by nutrients decisive for competitive success belowground.

Directory of Open Access Journals (Sweden)

Francisco M Padilla

Full Text Available Theory predicts that plant species win competition for a shared resource by more quickly preempting the resource in hotspots and by depleting resource levels to lower concentrations than its competitors. Competition in natural grasslands largely occurs belowground, but information regarding root interactions is limited, as molecular methods quantifying species abundance belowground have only recently become available.In monoculture, the grass Festuca rubra had higher root densities and a faster rate of soil nitrate depletion than Plantago lanceolata, projecting the first as a better competitor for nutrients. However, Festuca lost in competition with Plantago. Plantago not only replaced the lower root mass of its competitor, but strongly overproduced roots: with only half of the plants in mixture than in monoculture, Plantago root densities in mixture were similar or higher than those in its monocultures. These responses occurred equally in a nutrient-rich and nutrient-poor soil layer, and commenced immediately at the start of the experiment when root densities were still low and soil nutrient concentrations high.Our results suggest that species may achieve competitive superiority for nutrients by root growth stimulation prior to nutrient depletion, induced by the presence of a competitor species, rather than by a better ability to compete for nutrients per se. The root overproduction by which interspecific neighbors are suppressed independent of nutrient acquisition is consistent with predictions from game theory. Our results emphasize that root competition may be driven by other mechanisms than is currently assumed. The long-term consequences of these mechanisms for community dynamics are discussed.

Systemic above- and belowground cross talk: hormone-based responses triggered by Heterodera schachtii and shoot herbivores in Arabidopsis thaliana

Czech Academy of Sciences Publication Activity Database

Kammerhofer, N.; Egger, B.; Dobrev, Petre; Vaňková, Radomíra; Hofmann, J.; Schausberger, P.; Wieczorek, K.

2015-01-01

Roč. 66, č. 22 (2015), s. 7005-7017 ISSN 0022-0957 R&D Projects: GA MŠk LD14120 Institutional support: RVO:61389030 Keywords : Aboveground–belowground interactions * Frankliniella occidentalis * herbivores Subject RIV: EF - Botanics Impact factor: 5.677, year: 2015

Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host-parasite interactions.

Science.gov (United States)

Tao, Leiling; Gowler, Camden D; Ahmad, Aamina; Hunter, Mark D; de Roode, Jacobus C

2015-10-22

Host-parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host-parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host-parasite systems. © 2015 The Author(s).

Disease ecology across soil boundaries: effects of below-ground fungi on above-ground host–parasite interactions

Science.gov (United States)

Tao, Leiling; Gowler, Camden D.; Ahmad, Aamina; Hunter, Mark D.; de Roode, Jacobus C.

2015-01-01

Host–parasite interactions are subject to strong trait-mediated indirect effects from other species. However, it remains unexplored whether such indirect effects may occur across soil boundaries and connect spatially isolated organisms. Here, we demonstrate that, by changing plant (milkweed Asclepias sp.) traits, arbuscular mycorrhizal fungi (AMF) significantly affect interactions between a herbivore (the monarch butterfly Danaus plexippus) and its protozoan parasite (Ophryocystis elektroscirrha), which represents an interaction across four biological kingdoms. In our experiment, AMF affected parasite virulence, host resistance and host tolerance to the parasite. These effects were dependent on both the density of AMF and the identity of milkweed species: AMF indirectly increased disease in monarchs reared on some species, while alleviating disease in monarchs reared on other species. The species-specificity was driven largely by the effects of AMF on both plant primary (phosphorus) and secondary (cardenolides; toxins in milkweeds) traits. Our study demonstrates that trait-mediated indirect effects in disease ecology are extensive, such that below-ground interactions between AMF and plant roots can alter host–parasite interactions above ground. In general, soil biota may play an underappreciated role in the ecology of many terrestrial host–parasite systems. PMID:26468247

Relating belowground microbial composition to the taxonomic, phylogenetic, and functional trait distributions of trees in a tropical forest.

Science.gov (United States)

Barberán, Albert; McGuire, Krista L; Wolf, Jeffrey A; Jones, F Andrew; Wright, Stuart Joseph; Turner, Benjamin L; Essene, Adam; Hubbell, Stephen P; Faircloth, Brant C; Fierer, Noah

2015-12-01

The complexities of the relationships between plant and soil microbial communities remain unresolved. We determined the associations between plant aboveground and belowground (root) distributions and the communities of soil fungi and bacteria found across a diverse tropical forest plot. Soil microbial community composition was correlated with the taxonomic and phylogenetic structure of the aboveground plant assemblages even after controlling for differences in soil characteristics, but these relationships were stronger for fungi than for bacteria. In contrast to expectations, the species composition of roots in our soil core samples was a poor predictor of microbial community composition perhaps due to the patchy, ephemeral, and highly overlapping nature of fine root distributions. Our ability to predict soil microbial composition was not improved by incorporating information on plant functional traits suggesting that the most commonly measured plant traits are not particularly useful for predicting the plot-level variability in belowground microbial communities. © 2015 John Wiley & Sons Ltd/CNRS.

Career Guidance in India Based on O*NET and Cultural Variables

Science.gov (United States)

Bhatnagar, Mohit

2018-01-01

The Occupational Information Network (O*NET) is the primary source of occupational information in the United States (US). In this study, I review O*NET's usage for career guidance in India and conceive a career intervention based on it. In an empirical evaluation adopting a posttest-only experimental design with post-graduate management students…

Exploring long-term trends in land use change and aboveground human appropriation of net primary production in nine European countries

DEFF Research Database (Denmark)

Gingrich, Simone; Niedertscheider, Maria; Kastner, Thomas

2015-01-01

Profound changes in land use occurred during the last century in Europe, driven by growing population, changes in affluence, and technological innovation. To capture and understand these changes, we compiled a consistent dataset on the distribution of land-use types and biomass extraction for nine...... primary production" (HANPP) framework for the nine countries and for the sum of all countries on a yearly basis from 1902 to 2003. We find that cropland and grazing land contracted in all countries except Albania in the observed period, while forestland increased. Crop yields increased in all countries......, most strongly during the second half of the 20th century. In some countries, biomass extraction on grazing lands increased to a similar extent. Overall, HANPP was high but declined slightly from 63% of the net primary production of potential vegetation in 1902 to 55% in 2003. This is the result...

Assessment of Export Efficiency Equations in the Southern Ocean Applied to Satellite-Based Net Primary Production

Science.gov (United States)

Arteaga, Lionel; Haëntjens, Nils; Boss, Emmanuel; Johnson, Kenneth S.; Sarmiento, Jorge L.

2018-04-01

Carbon export efficiency (e-ratio) is defined as the fraction of organic carbon fixed through net primary production (NPP) that is exported out of the surface productive layer of the ocean. Recent observations for the Southern Ocean suggest a negative e-ratio versus NPP relationship, and a reduced dependency of export efficiency on temperature, different than in the global domain. In this study, we complement information from a passive satellite sensor with novel space-based lidar observations of ocean particulate backscattering to infer NPP over the entire annual cycle, and estimate Southern Ocean export rates from five different empirical models of export efficiency. Inferred Southern Ocean NPP falls within the range of previous studies, with a mean estimate of 15.8 (± 3.9) Pg C yr-1 for the region south of 30°S during the 2005-2016 period. We find that an export efficiency model that accounts for silica(Si)-ballasting, which is constrained by observations with a negative e-ratio versus NPP relationship, shows the best agreement with in situ-based estimates of annual net community production (annual export of 2.7 ± 0.6 Pg C yr-1 south of 30°S). By contrast, models based on the analysis of global observations with a positive e-ratio versus NPP relationship predict annually integrated export rates that are ˜ 33% higher than the Si-dependent model. Our results suggest that accounting for Si-induced ballasting is important for the estimation of carbon export in the Southern Ocean.

Cultivating engaged leadership through a learning collaborative: lessons from primary care renewal in Oregon safety net clinics.

Science.gov (United States)

McMullen, Carmit K; Schneider, Jennifer; Firemark, Alison; Davis, James; Spofford, Mark

2013-01-01

The aim of this study was to explore how learning collaboratives cultivate leadership skills that are essential for implementing patient-centered medical homes (PCMHs). We conducted an ethnographic evaluation of a payor-incentivized PCMH implementation in Oregon safety net clinics, known as Primary Care Renewal. Analyses primarily drew on in-depth interviews with organizational leaders who were involved in the initiative. We solicited perspectives on the history, barriers, facilitators, and other noteworthy factors related to the implementation of PCMH. We reviewed and summarized transcripts and created and applied a coding dictionary to identify emergent leadership themes. We reviewed field notes from clinic site visits and observations of learning collaborative activities for additional information on the role of engaged leadership. Interview data suggested that organizations followed a similar, sequential process of Primary Care Renewal implementation having 2 phases-inspiration and implementation-and that leaders needed and learned different leadership skills in each phase. Leaders reported that collaborative learning opportunities were critical for developing engaged leadership skills during the inspiration phase of transformation. Facilitative and modeling aspects of engaged leadership were most important for codesigning a vision and plan for change. Adaptive leadership skills became more important during the implementation phase, when specific operational and management skills were needed to foster standardization and spread of the Primary Care Renewal initiative throughout participating clinics. The PCMH has received much attention as a way to reorganize and potentially improve primary care. Documenting steps and stages for cultivating leaders with the vision and skills to transform their organizations into PCMHs may offer a useful roadmap to other organizations considering a similar transformation.

Modeling the spatial-temporal dynamics of net primary production in Yangtze River Basin using IBIS model

Science.gov (United States)

Zhang, Z.; Jiang, H.; Liu, J.; Zhu, Q.; Wei, X.; Jiang, Z.; Zhou, G.; Zhang, X.; Han, J.

2011-01-01

The climate change has significantly affected the carbon cycling in Yangtze River Basin. To better understand the alternation pattern for the relationship between carbon cycling and climate change, the net primary production (NPP) were simulated in the study area from 1956 to 2006 by using the Integrated Biosphere Simulator (IBIS). The results showed that the average annual NPP per square meter was about 0.518 kg C in Yangtze River Basin. The high NPP levels were mainly distributed in the southeast area of Sichuan, and the highest value reached 1.05 kg C/m2. The NPP increased based on the simulated temporal trends. The spatiotemporal variability of the NPP in the vegetation types was obvious, and it was depended on the climate and soil condition. We found the drought climate was one of critical factor that impacts the alterations of the NPP in the area by the simulation. ?? 2011 IEEE.

Global Human Appropriation of Net Primary Production and Associated Resource Decoupling: 2010-2050.

Science.gov (United States)

Zhou, Chuanbin; Elshkaki, Ayman; Graedel, T E

2018-02-06

Human appropriation of net primary production (HANPP) methodology has previously been developed to assess the intensity of anthropogenic extraction of biomass resources. However, there is limited analysis concerning future trends of HANPP. Here we present four scenarios for global biomass demand and HANPP harv (the most key component of HANPP) from 2010 to 2050 by incorporating data on expanded historical drivers and disaggregated biomass demand (food, wood material, and fuelwood). The results show that the biomass demand has the lowest value in the equitability world scenario (an egalitarian vision) and the highest value in the security foremost scenario (an isolationist vision). The biomass demand for food and materials increases over time, while fuelwood demand decreases over time. Global HANPP harv rises to between 8.5 and 10.1 Pg C/yr in 2050 in the four scenarios, 14-35% above its value in 2010, and some 50% of HANPP harv is calculated to be crop residues, wood residues, and food losses in the future. HANPP harv in developing regions (Asia, Africa, and Latin America) increases faster than that in more-developed regions (North America and Europe), due to urbanization, population growth, and increasing income. Decoupling of HANPP harv and socioeconomic development is also discussed in this work.

Net primary productivity of China's terrestrial ecosystems from a process model driven by remote sensing.

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Feng, X; Liu, G; Chen, J M; Chen, M; Liu, J; Ju, W M; Sun, R; Zhou, W

2007-11-01

The terrestrial carbon cycle is one of the foci in global climate change research. Simulating net primary productivity (NPP) of terrestrial ecosystems is important for carbon cycle research. In this study, China's terrestrial NPP was simulated using the Boreal Ecosystem Productivity Simulator (BEPS), a carbon-water coupled process model based on remote sensing inputs. For these purposes, a national-wide database (including leaf area index, land cover, meteorology, vegetation and soil) at a 1 km resolution and a validation database were established. Using these databases and BEPS, daily maps of NPP for the entire China's landmass in 2001 were produced, and gross primary productivity (GPP) and autotrophic respiration (RA) were estimated. Using the simulated results, we explore temporal-spatial patterns of China's terrestrial NPP and the mechanisms of its responses to various environmental factors. The total NPP and mean NPP of China's landmass were 2.235 GtC and 235.2 gCm(-2)yr(-1), respectively; the total GPP and mean GPP were 4.418 GtC and 465 gCm(-2)yr(-1); and the total RA and mean RA were 2.227 GtC and 234 gCm(-2)yr(-1), respectively. On average, NPP was 50.6% of GPP. In addition, statistical analysis of NPP of different land cover types was conducted, and spatiotemporal patterns of NPP were investigated. The response of NPP to changes in some key factors such as LAI, precipitation, temperature, solar radiation, VPD and AWC are evaluated and discussed.

Arbuscular Mycorrhizal Fungi and Plant Chemical Defence: Effects of Colonisation on Aboveground and Belowground Metabolomes.

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Hill, Elizabeth M; Robinson, Lynne A; Abdul-Sada, Ali; Vanbergen, Adam J; Hodge, Angela; Hartley, Sue E

2018-02-01

Arbuscular mycorrhizal fungal (AMF) colonisation of plant roots is one of the most ancient and widespread interactions in ecology, yet the systemic consequences for plant secondary chemistry remain unclear. We performed the first metabolomic investigation into the impact of AMF colonisation by Rhizophagus irregularis on the chemical defences, spanning above- and below-ground tissues, in its host-plant ragwort (Senecio jacobaea). We used a non-targeted metabolomics approach to profile, and where possible identify, compounds induced by AMF colonisation in both roots and shoots. Metabolomics analyses revealed that 33 compounds were significantly increased in the root tissue of AMF colonised plants, including seven blumenols, plant-derived compounds known to be associated with AMF colonisation. One of these was a novel structure conjugated with a malonyl-sugar and uronic acid moiety, hitherto an unreported combination. Such structural modifications of blumenols could be significant for their previously reported functional roles associated with the establishment and maintenance of AM colonisation. Pyrrolizidine alkaloids (PAs), key anti-herbivore defence compounds in ragwort, dominated the metabolomic profiles of root and shoot extracts. Analyses of the metabolomic profiles revealed an increase in four PAs in roots (but not shoots) of AMF colonised plants, with the potential to protect colonised plants from below-ground organisms.

Effects of above- and below-ground competition from shrubs on photosynthesis, transpiration and growth in Quercus robur L

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Anna M. Jensen; Magnus Lof; Emile S. Gardiner

2011-01-01

For a tree seedling to successfully establish in dense shrubbery, it must maintain function under heterogeneous resource availability. We evaluated leaf-level acclimation in photosynthetic capacity, seedling-level transpiration, and seedling morphology and growth to gain an understanding of the effects of above- and below-ground competition on Quercus robur seedlings....

Money for nothing? The net costs of medical training.

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Barros, Pedro P; Machado, Sara R

2010-09-01

One of the stages of medical training is the residency programme. Hosting institutions often claim compensation for the training provided. How much should this compensation be? According to our results, given the benefits arising from having residents among the house staff, no transfer (either tuition fee or subsidy) should be set to compensate the hosting institution for providing medical training. This paper quantifies the net costs of medical training, defined as the training costs over and above the wage paid. We jointly consider two effects. On the one hand, residents take extra time and resources from both the hosting institution and the supervisor. On the other hand, residents can be regarded as a less expensive substitute to nurses and/or graduate physicians, in the production of health care, both in primary care centres and hospitals. The net effect can be either positive or negative. We use the fact that residents, in Portugal, are centrally allocated to National Health Service hospitals to treat them as a fixed exogenous production factor. The data used comes from Portuguese hospitals and primary care centres. Cost function estimates point to a small negative marginal impact of residents on hospitals' (-0.02%) and primary care centres' (-0.9%) costs. Nonetheless, there is a positive relation between size and cost to the very large hospitals and primary care centres. Our approach to estimation of residents' costs controls for other teaching activities hospitals might have (namely undergraduate Medical Schools). Overall, the net costs of medical training appear to be quite small.

Responses of terrestrial ecosystems' net primary productivity to future regional climate change in China.

Science.gov (United States)

Zhao, Dongsheng; Wu, Shaohong; Yin, Yunhe

2013-01-01

The impact of regional climate change on net primary productivity (NPP) is an important aspect in the study of ecosystems' response to global climate change. China's ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund-Potsdam-Jena Dynamic Global Vegetation Model for China (LPJ-CN), a global dynamical vegetation model developed for China's terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change.

Responses of terrestrial ecosystems' net primary productivity to future regional climate change in China.

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Dongsheng Zhao

Full Text Available The impact of regional climate change on net primary productivity (NPP is an important aspect in the study of ecosystems' response to global climate change. China's ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund-Potsdam-Jena Dynamic Global Vegetation Model for China (LPJ-CN, a global dynamical vegetation model developed for China's terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change.

Comparing MODIS Net Primary Production Estimates with Terrestrial National Forest Inventory Data in Austria

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Mathias Neumann

2015-04-01

Full Text Available The mission of this study is to compare Net Primary Productivity (NPP estimates using (i forest inventory data and (ii spatio-temporally continuous MODIS (MODerate resolution Imaging Spectroradiometer remote sensing data for Austria. While forest inventories assess the change in forest growth based on repeated individual tree measurements (DBH, height etc., the MODIS NPP estimates are based on ecophysiological processes such as photosynthesis, respiration and carbon allocation. We obtained repeated national forest inventory data from Austria, calculated a “ground-based” NPP estimate and compared the results with “space-based” MODIS NPP estimates using different daily climate data. The MODIS NPP estimates using local Austrian climate data exhibited better compliance with the forest inventory driven NPP estimates than the MODIS NPP predictions using global climate data sets. Stand density plays a key role in addressing the differences between MODIS driven NPP estimates versus terrestrial driven inventory NPP estimates. After addressing stand density, both results are comparable across different scales. As forest management changes stand density, these findings suggest that management issues are important in understanding the observed discrepancies between MODIS and terrestrial NPP.

Production dynamics of fine roots in beech forests: possible mechanism of resource allocation between above- and below-ground production

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Nakahata, R.; Osawa, A.; Naramoto, M.; Mizunaga, H.; Sato, M.

2017-12-01

The masting phenomenon that seed production has large annual variation with spatial synchrony appears generally in beeches. Therefore, net primary production and carbon allocation mechanism in beech forests may differ among several years in relation to annual variation of seed production. On the other hand, fine roots play key roles in carbon dynamics and nutrient and water acquisition of an ecosystem. Evaluation of fine root dynamics is essential to understand long-term dynamics of production in forest ecosystems. Moreover, the influence of mast seeding on resource allocation should be clarified in such beech forests. The aim of this study is to clarify possible relationships between the patterns of above- and below-ground production in relation to the masting events using observation data of litter fall and fine root dynamics. We applied the litter trap method and a minirhizotron method in a cool-temperate natural forest dominated by beech (Fagus crenata Blume). Ten litter traps were set from 2008 to 2016, then annual leaf and seed production were estimated. Four minirhizotron tubes were buried in Aug. 2008 and soil profiles were scanned monthly until Nov. 2016 during the periods of no snow covering. The scanned soil profiles were analyzed for calculating fine root production using the WinRHIZO Tron software. In the present study site, rich production of mast seeding occurred biennially and fine root production showed various seasonal patterns. There was no significant correlation between seed production and annual fine root production in the same year. However, seed production had a positive correlation with fine root production in autumn in the previous year and indicated a negative correlation with that in autumn in the current year. These results indicate that higher fine root production has led to increased nutrient acquisition, which resulted in rich seed production in the next year. It is also suppressed after the masting events due to shortage in

Net primary production of forest-forming species in climatic gradients of Eurasia

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V. A. Usoltsev

2018-04-01

Full Text Available When using biomass and net primary production (NPP databases compiled by the authors for 6 forest-forming species in a number of 6694 and 2192 sample plots correspondingly, a system of regression models of their NPP is designed and some species-specific regularities of NPP distribution in two climatic gradients (natural zonality and climate continentality are stated. It is found that according to a zonal gradient, aboveground and total NPP in 2-needled pine and spruce-fir forests are monotonically increasing in the direction from the northern to the southern tip of the continent, while larch and birch have the maximum in the southern moderate, and aspen and poplar – in the northern moderate zone, but oak forests do not show any significant pattern. Within a single zonal belt, the aboveground and total NPP of coniferous and deciduous are monotonically decreasing in direction from the Atlantic and Pacific coasts to the continentality pole in Yakutia. The understory NPP of all the species, except oak, monotonically increase towards the subequatorial zone. For oak forests, any clear regularity is not revealed. Within a single zonal belt, when approaching continentality pole, Pinus and Quercus NPP monotonically decreases and in other species, increases. Species-specific patterns in changing the relative indices of NPP (forest stand underground NPP to aboveground one and forest understory NPP to total forest stand one in gradients of the natural zonality and climate continentality are established.

The supply and demand of net primary production in the Sahel

International Nuclear Information System (INIS)

Abdi, A M; Seaquist, J; Tenenbaum, D E; Eklundh, L; Ardö, J

2014-01-01

Net primary production (NPP) is the principal source of energy for ecosystems and, by extension, human populations that depend on them. The relationship between the supply and demand of NPP is important for the assessment of socio-ecological vulnerability. We present an analysis of the supply and demand of NPP in the Sahel using NPP estimates from the MODIS sensor and agri-environmental data from FAOSTAT. This synergistic approach allows for a spatially explicit estimation of human impact on ecosystems. We estimated the annual amount of NPP required to derive food, fuel and feed between 2000 and 2010 for 22 countries in sub-Saharan Africa. When comparing annual estimates of supply and demand of NPP, we found that demand increased from 0.44 PgC to 1.13 PgC, representing 19% and 41%, respectively, of available supply due to a 31% increase in the human population between 2000 and 2010. The demand for NPP has been increasing at an annual rate of 2.2% but NPP supply was near-constant with an inter-annual variability of approximately 1.7%. Overall, there were statistically significant (p < 0.05) increases in the NPP of cropland (+6.0%), woodland (+6.1%) and grassland/savanna (+9.4%), and a decrease in the NPP of forests (−0.7%). On the demand side, the largest increase was for food (20.4%) followed by feed (16.7%) and fuel (5.5%). The supply-demand balance of NPP is a potentially important tool from the standpoint of sustainable development, and as an indicator of stresses on the environment stemming from increased consumption of biomass. (letter)

Influence of presence and spatial arrangement of belowground insects on host-plant selection of aboveground insects: a field study

NARCIS (Netherlands)

Soler, J.J.; Schaper, S.V.; Bezemer, T.M.; Cortesero, A.M.; Hoffmeister, T.S.; Van der Putten, W.H.; Vet, L.E.M.; Harvey, J.A.

2009-01-01

1. Several studies have shown that above- and belowground insects can interact by influencing each others growth, development, and survival when they feed on the same host-plant. In natural systems, however, insects can make choices on which plants to oviposit and feed. A field experiment was

Examination of Below-Ground Structure and Soil Respiration Rates of Stable and Deteriorating Salt Marshes in Jamaica Bay (NY)

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CAT scan imaging is currently being used to examine below-ground peat and root structure in cores collected from salt marshes of Jamaica Bay, part of the Gateway National Recreation Area (NY). CAT scans or Computer-Aided Tomography scans use X-ray equipment to produce multiple i...

A biophysical process based approach for estimating net primary production using satellite and ground observations

Science.gov (United States)

Choudhury, Bhaskar J.

An approach is presented for calculating interannual variation of net primary production (C) of terrestrial plant communities at regional scale using satellite and ground measurements. C has been calculated as the difference of gross photosynthesis (A g) and respiration (R), recognizing that different biophysical factors exert major control on these two processes. A g has been expressed as the product of radiation use efficiency for gross photosynthesis by an unstressed canopy and intercepted photosynthetically active radiation, which is then adjusted for stresses due to soil water shortage and temperature away from optimum. R has been calculated as the sum of growth and maintenance components (respectively, R g and R m. The R m has been determined from nitrogen content of plant tissue per unit ground area, while R g has been obtained as a fraction of the difference of A g and R m. Model parameters have not been determined by matching the calculated fluxes against observations at any location. Results are presented for cultivated and temperate deciduous forest areas over North America for five consecutive years (1986-1990) and compared with observations.

Assessing the impact of the urbanization process on net primary productivity in China in 1989-2000.

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Tian, Guangjin; Qiao, Zhi

2014-01-01

Urban development affects the material circulation and energy flow of ecosystems, thereby affecting the Net Primary Productivity (NPP). The loss of NPP due to urban expansion was calculated integrating GLO-PEM with remote sensing and GIS techniques in China during the period of 1989-2000. Using urban expansion and the mean NPP for the different land use types in the fourteen regions, the total loss of NPP was calculated as 0.95 Tg C, which accounted for 0.03% of the national NPP of 1989. The total loss of NPP due to the transformation from cropland to urban land accounted for 91.93%, followed by forest (7.17%) and grassland (0.69%). However, the conversion from unused land, industrial and construction land, and water bodies to urban land resulted in an increase in the NPP. The regions locating in eastern China and middle China had large reductions in the total NPP due to urban expansion. Copyright © 2013 Elsevier Ltd. All rights reserved.

Horizontal ichthyoplankton tow-net system with unobstructed net opening

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Nester, Robert T.

1987-01-01

The larval fish sampler described here consists of a modified bridle, frame, and net system with an obstruction-free net opening and is small enough for use on boats 10 m or less in length. The tow net features a square net frame attached to a 0.5-m-diameter cylinder-on-cone plankton net with a bridle designed to eliminate all obstructions forward of the net opening, significantly reducing currents and vibrations in the water directly preceding the net. This system was effective in collecting larvae representing more than 25 species of fish at sampling depths ranging from surface to 10 m and could easily be used at greater depths.

Asymmetric Responses of Primary Productivity to Altered Precipitation Simulated by Land Surface Models across Three Long-term Grassland Sites

Science.gov (United States)

Wu, D.; Ciais, P.; Viovy, N.; Knapp, A.; Wilcox, K.; Bahn, M.; Smith, M. D.; Ito, A.; Arneth, A.; Harper, A. B.; Ukkola, A.; Paschalis, A.; Poulter, B.; Peng, C.; Reick, C. H.; Hayes, D. J.; Ricciuto, D. M.; Reinthaler, D.; Chen, G.; Tian, H.; Helene, G.; Zscheischler, J.; Mao, J.; Ingrisch, J.; Nabel, J.; Pongratz, J.; Boysen, L.; Kautz, M.; Schmitt, M.; Krohn, M.; Zeng, N.; Meir, P.; Zhang, Q.; Zhu, Q.; Hasibeder, R.; Vicca, S.; Sippel, S.; Dangal, S. R. S.; Fatichi, S.; Sitch, S.; Shi, X.; Wang, Y.; Luo, Y.; Liu, Y.; Piao, S.

2017-12-01

Changes in precipitation variability including the occurrence of extreme events strongly influence plant growth in grasslands. Field measurements of aboveground net primary production (ANPP) in temperate grasslands suggest a positive asymmetric response with wet years resulting in ANPP gains larger than ANPP declines in dry years. Whether land surface models used for historical simulations and future projections of the coupled carbon-water system in grasslands are capable to simulate such non-symmetrical ANPP responses remains an important open research question. In this study, we evaluate the simulated responses of grassland primary productivity to altered precipitation with fourteen land surface models at the three sites of Colorado Shortgrass Steppe (SGS), Konza prairie (KNZ) and Stubai Valley meadow (STU) along a rainfall gradient from dry to wet. Our results suggest that: (i) Gross primary production (GPP), NPP, ANPP and belowground NPP (BNPP) show nonlinear response curves (concave-down) in all the models, but with different curvatures and mean values. In contrast across the sites, primary production increases and then saturates along increasing precipitation with a flattening at the wetter site. (ii) Slopes of spatial relationships between modeled primary production and precipitation are steeper than the temporal slopes (obtained from inter-annual variations). (iii) Asymmetric responses under nominal precipitation range with modeled inter-annual primary production show large uncertainties, and model-ensemble median generally suggests negative asymmetry (greater declines in dry years than increases in wet years) across the three sites. (iv) Primary production at the drier site is predicted to more sensitive to precipitation compared to wetter site, and median sensitivity consistently indicates greater negative impacts of reduced precipitation than positive effects of increased precipitation under extreme conditions. This study implies that most models

Higher-moment measurements of net-kaon, net-charge and net-proton multiplicity distributions at STAR

International Nuclear Information System (INIS)

Sarkar, Amal

2014-01-01

In this paper, we report the measurements of the various moments, such as mean, standard deviation (σ), skewness (S) and kurtosis (κ) of the net-kaon, net-charge and net-proton multiplicity distributions at mid-rapidity in Au + Au collisions from √(s NN )=7.7 to 200 GeV with the STAR experiment at RHIC. This work has been done with the aim to locate the critical point on the QCD phase diagram. These moments and their products are related to the thermodynamic susceptibilities of conserved quantities such as net baryon number, net charge, and net strangeness as well as to the correlation length of the system which diverges in an ideal infinite thermodynamic system at the critical point. For a finite system, existing for a finite time, a non-monotonic behavior of these variables would indicate the presence of the critical point. Furthermore, we also present the moment products Sσ, κσ 2 of net-kaon, net-charge and net-proton multiplicity distributions as a function of collision centrality and energy. The energy and the centrality dependence of higher moments and their products have been compared with different models

Applications of the aqueous self-cooled blanket (ASCB) concept to the Next European Torus (NET)

International Nuclear Information System (INIS)

Embrechts, M.J.; Bogaerts, W.; Cardella, A.; Chazalon, M.; Danner, W.; Dinner, P.; Libin, B.

1987-01-01

The Aqueous Self-Cooled Blanket Concept (ASCB) leads to a low-technology blanket design that relies on just structural material and coolant with small amounts of lithium compound dissolved in the coolant to provide for tritium production. The application of the ASCB concept in NET is being considered as a driver blanket that would operate at low temperature and low pressure and provide a reliable environment for machine operation during the technology phase. Shielding and tritium production are the primary objectives for such a low-technology blanket. Net tritium breeding is not a design requirement per se for a driver blanket for NET. A DEMO relevant ASCB based blanket test module with (local) tritium self-sufficiency and energy recovery as primary objectives might also be tested in NET if future developments confirm their viability

Below-ground process responses to elevated CO2 and temperature: a discussion of observations, measurement methods, and models

Science.gov (United States)

Elise Pendall; Scott Bridgham; Paul J. Hanson; Bruce Hungate; David W. Kicklighter; Dale W. Johnson; Beverly E. Law; Yiqi Luo; J. Patrick Megonigal; Maria Olsrud; Michael G. Ryan; Shiqiang Wan

2004-01-01

Rising atmospheric CO2 and temperatures are probably altering ecosystem carbon cycling, causing both positive and negative feedbacks to climate. Below-ground processes play a key role in the global carbon (C) cycle because they regulate storage of large quantities of C, and are potentially very sensitive to direct and indirect effects of elevated...

Above- and below-ground competition in high and low irradiance: tree seedling responses to a competing liana Byttneria grandifolia

NARCIS (Netherlands)

Chen, J.Y.; Bongers, F.; Cao, K.F.; Cai, Z.Q.

2008-01-01

Abstract: In tropical forests, trees compete not only with other trees, but also with lianas, which may limit tree growth and regeneration. Liana effects may depend on the availability of above- and below-ground resources and differ between tree species. We conducted a shade house experiment to test

Controls on the variability of net infiltration to desert sandstone

Science.gov (United States)

Heilweil, Victor M.; McKinney, Tim S.; Zhdanov, Michael S.; Watt, Dennis E.

2007-01-01

As populations grow in arid climates and desert bedrock aquifers are increasingly targeted for future development, understanding and quantifying the spatial variability of net infiltration becomes critically important for accurately inventorying water resources and mapping contamination vulnerability. This paper presents a conceptual model of net infiltration to desert sandstone and then develops an empirical equation for its spatial quantification at the watershed scale using linear least squares inversion methods for evaluating controlling parameters (independent variables) based on estimated net infiltration rates (dependent variables). Net infiltration rates used for this regression analysis were calculated from environmental tracers in boreholes and more than 3000 linear meters of vadose zone excavations in an upland basin in southwestern Utah underlain by Navajo sandstone. Soil coarseness, distance to upgradient outcrop, and topographic slope were shown to be the primary physical parameters controlling the spatial variability of net infiltration. Although the method should be transferable to other desert sandstone settings for determining the relative spatial distribution of net infiltration, further study is needed to evaluate the effects of other potential parameters such as slope aspect, outcrop parameters, and climate on absolute net infiltration rates.

Invasive plant suppresses the growth of native tree seedlings by disrupting belowground mutualisms.

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Kristina A Stinson

2006-05-01

Full Text Available The impact of exotic species on native organisms is widely acknowledged, but poorly understood. Very few studies have empirically investigated how invading plants may alter delicate ecological interactions among resident species in the invaded range. We present novel evidence that antifungal phytochemistry of the invasive plant, Alliaria petiolata, a European invader of North American forests, suppresses native plant growth by disrupting mutualistic associations between native canopy tree seedlings and belowground arbuscular mycorrhizal fungi. Our results elucidate an indirect mechanism by which invasive plants can impact native flora, and may help explain how this plant successfully invades relatively undisturbed forest habitat.

An exploratory study of treated-bed nets in Timor-Leste: patterns of intended and alternative usage

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Wilder-Smith Annelies

2011-07-01

Full Text Available Abstract Background The Timor-Leste Ministry of Health has recently finalized the National Malaria Control Strategy for 2010-2020. A key component of this roadmap is to provide universal national coverage with long-lasting insecticide-treated nets (LLINs in support of achieving the primary goal of reducing both morbidity and mortality from malaria by 30% in the first three years, followed by a further reduction of 20% by end of the programme cycle in 2020 1. The strategic plan calls for this target to be supported by a comprehensive information, education and communication (IEC programme; however, there is limited prior research into household and personal usage patterns to assist in the creation of targeted, effective, and socio-culturally specific behaviour change materials. Methods Nine separate focus group discussions (FGDs were carried out in Dili, Manatuto, and Covalima districts, Democratic Republic of Timor-Leste, in July 2010. These focus groups primarily explored themes of perceived malaria risk, causes of malaria, net usage patterns within families, barriers to correct and consistent usage, and the daily experience of users (both male and female in households with at least one net. Comprehensive qualitative analysis utilized open source analysis software. Results The primary determinants of net usage were a widespread perception that nets could or should only be used by pregnant women and young children, and the availability of sufficient sleeping space under a limited number of nets within households. Both nuisance biting and disease prevention were commonly cited as primary motivations for usage, while seasonality was not a significant factor. Long-term net durability and ease of hanging were seen as key attributes in net design preference. Very frequent washing cycles were common, potentially degrading net effectiveness. Finally, extensive re-purposing of nets (fishing, protecting crops was both reported and observed, and may

Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy covariance, biometric and continuous soil chamber measurements

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D. Zanotelli

2013-05-01

Full Text Available Carbon use efficiency (CUE, the ratio of net primary production (NPP over gross primary production (GPP, is a functional parameter that could possibly link the current increasingly accurate global GPP estimates with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, NPP and allocation patterns in different plant organs in an apple orchard during a complete year (2010. We applied a measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard, both net ecosystem production and gross primary production on a yearly basis, 380 ± 30 g C m−2 and 1263 ± 189 g C m−2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruit: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 �

Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy-covariance, biometric and continuous soil chamber measurements

Science.gov (United States)

Zanotelli, D.; Montagnani, L.; Manca, G.; Tagliavini, M.

2012-10-01

Carbon use efficiency (CUE) is a functional parameter that could possibly link the current increasingly accurate global estimates of gross primary production with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, net primary production (NPP) and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a~measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross-check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard both net ecosystem production and gross primary production on yearly basis, 380 ± 30 g C m-2 and 1263 ± 189 g C m-2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruits: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.09, was higher than the previously suggested

Net primary productivity, allocation pattern and carbon use efficiency in an apple orchard assessed by integrating eddy covariance, biometric and continuous soil chamber measurements

Science.gov (United States)

Zanotelli, D.; Montagnani, L.; Manca, G.; Tagliavini, M.

2013-05-01

Carbon use efficiency (CUE), the ratio of net primary production (NPP) over gross primary production (GPP), is a functional parameter that could possibly link the current increasingly accurate global GPP estimates with those of net ecosystem exchange, for which global predictors are still unavailable. Nevertheless, CUE estimates are actually available for only a few ecosystem types, while information regarding agro-ecosystems is scarce, in spite of the simplified spatial structure of these ecosystems that facilitates studies on allocation patterns and temporal growth dynamics. We combined three largely deployed methods, eddy covariance, soil respiration and biometric measurements, to assess monthly values of CUE, NPP and allocation patterns in different plant organs in an apple orchard during a complete year (2010). We applied a measurement protocol optimized for quantifying monthly values of carbon fluxes in this ecosystem type, which allows for a cross check between estimates obtained from different methods. We also attributed NPP components to standing biomass increments, detritus cycle feeding and lateral exports. We found that in the apple orchard, both net ecosystem production and gross primary production on a yearly basis, 380 ± 30 g C m-2 and 1263 ± 189 g C m-2 respectively, were of a magnitude comparable to those of natural forests growing in similar climate conditions. The largest differences with respect to forests are in the allocation pattern and in the fate of produced biomass. The carbon sequestered from the atmosphere was largely allocated to production of fruit: 49% of annual NPP was taken away from the ecosystem through apple production. Organic material (leaves, fine root litter, pruned wood and early fruit falls) contributing to the detritus cycle was 46% of the NPP. Only 5% was attributable to standing biomass increment, while this NPP component is generally the largest in forests. The CUE, with an annual average of 0.71 ± 0.12, was higher

Root biomass, turnover and net primary productivity of a coffee agroforestry system in Costa Rica: effects of soil depth, shade trees, distance to row and coffee age.

Science.gov (United States)

Defrenet, Elsa; Roupsard, Olivier; Van den Meersche, Karel; Charbonnier, Fabien; Pastor Pérez-Molina, Junior; Khac, Emmanuelle; Prieto, Iván; Stokes, Alexia; Roumet, Catherine; Rapidel, Bruno; de Melo Virginio Filho, Elias; Vargas, Victor J; Robelo, Diego; Barquero, Alejandra; Jourdan, Christophe

2016-08-21

In Costa Rica, coffee (Coffea arabica) plants are often grown in agroforests. However, it is not known if shade-inducing trees reduce coffee plant biomass through root competition, and hence alter overall net primary productivity (NPP). We estimated biomass and NPP at the stand level, taking into account deep roots and the position of plants with regard to trees. Stem growth and root biomass, turnover and decomposition were measured in mixed coffee/tree (Erythrina poeppigiana) plantations. Growth ring width and number at the stem base were estimated along with stem basal area on a range of plant sizes. Root biomass and fine root density were measured in trenches to a depth of 4 m. To take into account the below-ground heterogeneity of the agroforestry system, fine root turnover was measured by sequential soil coring (to a depth of 30 cm) over 1 year and at different locations (in full sun or under trees and in rows/inter-rows). Allometric relationships were used to calculate NPP of perennial components, which was then scaled up to the stand level. Annual ring width at the stem base increased up to 2·5 mm yr -1 with plant age (over a 44-year period). Nearly all (92 %) coffee root biomass was located in the top 1·5 m, and only 8 % from 1·5 m to a depth of 4 m. Perennial woody root biomass was 16 t ha -1 and NPP of perennial roots was 1·3 t ha -1 yr -1 Fine root biomass (0-30 cm) was two-fold higher in the row compared with between rows. Fine root biomass was 2·29 t ha -1 (12 % of total root biomass) and NPP of fine roots was 2·96 t ha -1 yr -1 (69 % of total root NPP). Fine root turnover was 1·3 yr -1 and lifespan was 0·8 years. Coffee root systems comprised 49 % of the total plant biomass; such a high ratio is possibly a consequence of shoot pruning. There was no significant effect of trees on coffee fine root biomass, suggesting that coffee root systems are very competitive in the topsoil. © The Author 2016. Published by Oxford University Press on

Aboveground Net Primary Productivity in a Riparian Wetland Following Restoration of Hydrology.

Science.gov (United States)

Koontz, Melissa; Lundberg, Christopher; Lane, Robert; Day, John; Pezeshki, Reza

2016-02-04

This research presents the initial results of the effects of hydrological restoration on forested wetlands in the Mississippi alluvial plain near Memphis, Tennessee. Measurements were carried out in a secondary channel, the Loosahatchie Chute, in which rock dikes were constructed in the 1960s to keep most flow in the main navigation channel. In 2008-2009, the dikes were notched to allow more flow into the secondary channel. Study sites were established based on relative distance downstream of the notched dikes. Additionally, a reference site was established north of the Loosahatchie Chute where the dikes remained unnotched. We compared various components of vegetation composition and productivity at sites in the riparian wetlands for two years. Salix nigra had the highest Importance Value at every site. Species with minor Importance Values were Celtis laevigata, Acer rubrum, and Plantanus occidentalis. Productivity increased more following the introduction of river water in affected sites compared to the reference. Aboveground net primary productivity was highest at the reference site (2926 ± 458.1 g·m(-2)·year(-1)), the intact site; however, there were greater increase at the sites in the Loosahatchie Chute, where measurements ranged from 1197.7 ± 160.0 g m(-2)·year(-1)·to 2874.2 ± 794.0 g·m(-2)·year(-1). The site furthest from the notching was the most affected. Pulsed inputs into these wetlands may enhance forested wetland productivity. Continued monitoring will quantify impacts of restored channel hydrology along the Mississippi River.

Aboveground Net Primary Productivity in a Riparian Wetland Following Restoration of Hydrology

Directory of Open Access Journals (Sweden)

Melissa Koontz

2016-02-01

Full Text Available This research presents the initial results of the effects of hydrological restoration on forested wetlands in the Mississippi alluvial plain near Memphis, Tennessee. Measurements were carried out in a secondary channel, the Loosahatchie Chute, in which rock dikes were constructed in the 1960s to keep most flow in the main navigation channel. In 2008–2009, the dikes were notched to allow more flow into the secondary channel. Study sites were established based on relative distance downstream of the notched dikes. Additionally, a reference site was established north of the Loosahatchie Chute where the dikes remained unnotched. We compared various components of vegetation composition and productivity at sites in the riparian wetlands for two years. Salix nigra had the highest Importance Value at every site. Species with minor Importance Values were Celtis laevigata, Acer rubrum, and Plantanus occidentalis. Productivity increased more following the introduction of river water in affected sites compared to the reference. Aboveground net primary productivity was highest at the reference site (2926 ± 458.1 g·m−2·year−1, the intact site; however, there were greater increase at the sites in the Loosahatchie Chute, where measurements ranged from 1197.7 ± 160.0 g m−2·year−1·to 2874.2 ± 794.0 g·m−2·year−1. The site furthest from the notching was the most affected. Pulsed inputs into these wetlands may enhance forested wetland productivity. Continued monitoring will quantify impacts of restored channel hydrology along the Mississippi River.

Co-occurring woody species have diverse hydraulic strategies and mortality rates during an extreme drought: Belowground hydraulic failure during drought

Energy Technology Data Exchange (ETDEWEB)

Johnson, Daniel M. [College of Natural Resources, University of Idaho, Moscow ID 83844 USA; Domec, Jean-Christophe [Bordeaux Sciences Agro, UMR INRA-ISPA 1391, Gradignan 33195 France; Nicholas School of the Environment, Duke University, Durham NC 27708 USA; Carter Berry, Z. [College of Natural Resources, University of Idaho, Moscow ID 83844 USA; Department of Natural Resources and the Environment, University of New Hampshire, Durham NH 03824 USA; Schwantes, Amanda M. [Nicholas School of the Environment, Duke University, Durham NC 27708 USA; McCulloh, Katherine A. [Department of Botany, University of Wisconsin-Madison, Madison WI 53705 USA; Woodruff, David R. [US Forest Service, Pacific Northwest Research Station, Corvallis OR 97331 USA; Wayne Polley, H. [Grassland, Soil & Water Research Laboratory USDA-Agricultural Research Service, Temple TX 76502 USA; Wortemann, Remí [INRA Nancy, UMR INRA-UL 1137 Ecologie et Ecophysiologie Forestières, Champenoux 54280 France; Swenson, Jennifer J. [Nicholas School of the Environment, Duke University, Durham NC 27708 USA; Scott Mackay, D. [Department of Geography, State University of New York, Buffalo NY 14261 USA; McDowell, Nate G. [Pacific Northwest National Laboratory, Richland WA 99352 USA; Jackson, Robert B. [Department of Earth System Science, Woods Institute for the Environment, and Precourt Institute for Energy, Stanford University, Stanford CA 94305 USA

2018-01-29

From 2011 to 2013, Texas experienced its worst drought in recorded history. This event provided a unique natural experiment to assess species-specific responses to extreme drought and mortality of four co-occurring woody species: Quercus fusiformis, Diospyros texana, Prosopis glandulosa and Juniperus ashei. We examined hypothesized mechanisms that could promote these species’ diverse mortality patterns using post-drought measurements on surviving trees coupled to retrospective process modeling. The species exhibited a wide range of gas exchange responses, hydraulic strategies, and mortality rates. Multiple proposed indices of mortality mechanisms were not consistent with the observed mortality patterns across species, including measures of iso/anisohydry, photosynthesis, carbohydrate depletion, and hydraulic safety margins. Large losses of growing season whole-tree conductance (driven by belowground losses of conductance), and shallower rooting depths, were associated with species that exhibited greater mortality. Based on this retrospective analysis, we suggest that species more vulnerable to drought were more likely to have succumbed to hydraulic failure belowground.

Responses of Terrestrial Ecosystems’ Net Primary Productivity to Future Regional Climate Change in China

Science.gov (United States)

Zhao, Dongsheng; Wu, Shaohong; Yin, Yunhe

2013-01-01

The impact of regional climate change on net primary productivity (NPP) is an important aspect in the study of ecosystems’ response to global climate change. China’s ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund–Potsdam–Jena Dynamic Global Vegetation Model for China (LPJ-CN), a global dynamical vegetation model developed for China’s terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change. PMID:23593325

Below-ground plant parts emit herbivore-induced volatiles: olfactory responses of a predatory mite to tulip bulbs infested by rust mites

NARCIS (Netherlands)

Aratchige, N.S.; Lesna, I.; Sabelis, M.W.

2004-01-01

Although odour-mediated interactions among plants, spider mites and predatory mites have been extensively studied above-ground, belowground studies are in their infancy. In this paper, we investigate whether feeding by rust mites (Aceria tulipae) cause tulip bulbs to produce odours that attract

Asymmetric warming significantly affects net primary production, but not ecosystem carbon balances of forest and grassland ecosystems in northern China.

Science.gov (United States)

Su, Hongxin; Feng, Jinchao; Axmacher, Jan C; Sang, Weiguo

2015-03-13

We combine the process-based ecosystem model (Biome-BGC) with climate change-scenarios based on both RegCM3 model outputs and historic observed trends to quantify differential effects of symmetric and asymmetric warming on ecosystem net primary productivity (NPP), heterotrophic respiration (Rh) and net ecosystem productivity (NEP) of six ecosystem types representing different climatic zones of northern China. Analysis of covariance shows that NPP is significant greater at most ecosystems under the various environmental change scenarios once temperature asymmetries are taken into consideration. However, these differences do not lead to significant differences in NEP, which indicates that asymmetry in climate change does not result in significant alterations of the overall carbon balance in the dominating forest or grassland ecosystems. Overall, NPP, Rh and NEP are regulated by highly interrelated effects of increases in temperature and atmospheric CO2 concentrations and precipitation changes, while the magnitude of these effects strongly varies across the six sites. Further studies underpinned by suitable experiments are nonetheless required to further improve the performance of ecosystem models and confirm the validity of these model predictions. This is crucial for a sound understanding of the mechanisms controlling the variability in asymmetric warming effects on ecosystem structure and functioning.

Asymmetric warming significantly affects net primary production, but not ecosystem carbon balances of forest and grassland ecosystems in northern China

Science.gov (United States)

Su, Hongxin; Feng, Jinchao; Axmacher, Jan C.; Sang, Weiguo

2015-03-01

We combine the process-based ecosystem model (Biome-BGC) with climate change-scenarios based on both RegCM3 model outputs and historic observed trends to quantify differential effects of symmetric and asymmetric warming on ecosystem net primary productivity (NPP), heterotrophic respiration (Rh) and net ecosystem productivity (NEP) of six ecosystem types representing different climatic zones of northern China. Analysis of covariance shows that NPP is significant greater at most ecosystems under the various environmental change scenarios once temperature asymmetries are taken into consideration. However, these differences do not lead to significant differences in NEP, which indicates that asymmetry in climate change does not result in significant alterations of the overall carbon balance in the dominating forest or grassland ecosystems. Overall, NPP, Rh and NEP are regulated by highly interrelated effects of increases in temperature and atmospheric CO2 concentrations and precipitation changes, while the magnitude of these effects strongly varies across the six sites. Further studies underpinned by suitable experiments are nonetheless required to further improve the performance of ecosystem models and confirm the validity of these model predictions. This is crucial for a sound understanding of the mechanisms controlling the variability in asymmetric warming effects on ecosystem structure and functioning.

Primary productivity as a control over soil microbial diversity along environmental gradients in a polar desert ecosystem

Directory of Open Access Journals (Sweden)

Kevin M. Geyer

2017-07-01

Full Text Available Primary production is the fundamental source of energy to foodwebs and ecosystems, and is thus an important constraint on soil communities. This coupling is particularly evident in polar terrestrial ecosystems where biological diversity and activity is tightly constrained by edaphic gradients of productivity (e.g., soil moisture, organic carbon availability and geochemical severity (e.g., pH, electrical conductivity. In the McMurdo Dry Valleys of Antarctica, environmental gradients determine numerous properties of soil communities and yet relatively few estimates of gross or net primary productivity (GPP, NPP exist for this region. Here we describe a survey utilizing pulse amplitude modulation (PAM fluorometry to estimate rates of GPP across a broad environmental gradient along with belowground microbial diversity and decomposition. PAM estimates of GPP ranged from an average of 0.27 μmol O2/m2/s in the most arid soils to an average of 6.97 μmol O2/m2/s in the most productive soils, the latter equivalent to 217 g C/m2/y in annual NPP assuming a 60 day growing season. A diversity index of four carbon-acquiring enzyme activities also increased with soil productivity, suggesting that the diversity of organic substrates in mesic environments may be an additional driver of microbial diversity. Overall, soil productivity was a stronger predictor of microbial diversity and enzymatic activity than any estimate of geochemical severity. These results highlight the fundamental role of environmental gradients to control community diversity and the dynamics of ecosystem-scale carbon pools in arid systems.

Net-baryon-, net-proton-, and net-charge kurtosis in heavy-ion collisions within a relativistic transport approach

International Nuclear Information System (INIS)

Nahrgang, Marlene; Schuster, Tim; Stock, Reinhard; Mitrovski, Michael; Bleicher, Marcus

2012-01-01

We explore the potential of net-baryon, net-proton and net-charge kurtosis measurements to investigate the properties of hot and dense matter created in relativistic heavy-ion collisions. Contrary to calculations in a grand-canonical ensemble we explicitly take into account exact electric and baryon charge conservation on an event-by-event basis. This drastically limits the width of baryon fluctuations. A simple model to account for this is to assume a grand-canonical distribution with a sharp cut-off at the tails. We present baseline predictions of the energy dependence of the net-baryon, net-proton and net-charge kurtosis for central (b≤2.75 fm) Pb+Pb/Au+Au collisions from E lab =2A GeV to √(s NN )=200 GeV from the UrQMD model. While the net-charge kurtosis is compatible with values around zero, the net-baryon number decreases to large negative values with decreasing beam energy. The net-proton kurtosis becomes only slightly negative for low √(s NN ). (orig.)

Above- and belowground linkages in Sphagnum peatland: climate warming affects plant-microbial interactions.

Science.gov (United States)

Jassey, Vincent E J; Chiapusio, Geneviève; Binet, Philippe; Buttler, Alexandre; Laggoun-Défarge, Fatima; Delarue, Frédéric; Bernard, Nadine; Mitchell, Edward A D; Toussaint, Marie-Laure; Francez, André-Jean; Gilbert, Daniel

2013-03-01

Peatlands contain approximately one third of all soil organic carbon (SOC). Warming can alter above- and belowground linkages that regulate soil organic carbon dynamics and C-balance in peatlands. Here we examine the multiyear impact of in situ experimental warming on the microbial food web, vegetation, and their feedbacks with soil chemistry. We provide evidence of both positive and negative impacts of warming on specific microbial functional groups, leading to destabilization of the microbial food web. We observed a strong reduction (70%) in the biomass of top-predators (testate amoebae) in warmed plots. Such a loss caused a shortening of microbial food chains, which in turn stimulated microbial activity, leading to slight increases in levels of nutrients and labile C in water. We further show that warming altered the regulatory role of Sphagnum-polyphenols on microbial community structure with a potential inhibition of top predators. In addition, warming caused a decrease in Sphagnum cover and an increase in vascular plant cover. Using structural equation modelling, we show that changes in the microbial food web affected the relationships between plants, soil water chemistry, and microbial communities. These results suggest that warming will destabilize C and nutrient recycling of peatlands via changes in above- and belowground linkages, and therefore, the microbial food web associated with mosses will feedback positively to global warming by destabilizing the carbon cycle. This study confirms that microbial food webs thus constitute a key element in the functioning of peatland ecosystems. Their study can help understand how mosses, as ecosystem engineers, tightly regulate biogeochemical cycling and climate feedback in peatlands. © 2012 Blackwell Publishing Ltd.

Modelling the dynamics of total precipitation and aboveground net primary production of fescue-feather grass steppe at Askania Nova according to global climate change scenariosModelling the dynamics of total precipitation and aboveground net primary production of fescue-feather grass steppe at Askania Nova according to global climate change scenarios

Directory of Open Access Journals (Sweden)

S. O. Belyakov

2017-01-01

Full Text Available This article discusses modelling of Aboveground Net Primary Production (ANPP of steppe (arid grassland ecosystems plant species in relation to changes in total precipitation over the previous year at the “Stara” study site, Biosphere Reserve “Askania-Nova”, Khersonregion (Ukraine. To investigate linkages between precipitation and Aboveground Net Primary Production, correlation analysis was chosen and a time series regression analysis was based on the data set for the period 1988–2012. The NPP dependence on quantity of precipitation was found to be more significant for the previous autumn-winter-spring period (AWSP than for the previous 12 month period. A regression model of ANPP’s dependence on AWSP is proposed. This model was further validated by the authors’ samples of ANPP, collected at the “Stara” study site in 2013–2016. The regression model showed a non-linear (quadratic dependence of net primary production of zonal and intrazonal plant coenoses and total precipitation for the autumn-winter-spring period for arid grasslands with a coefficient of determination equal to 0.54 and significance level less than 0.05. The non-linear equation for these relations, visualized by a parabola curve, was calculated using the Nonlinear Least-Squares Regression Method. The data set, based on calculated predicted values, using the calculated equation, had a similar dynamic to the historical data on ANPP, but the model could not predict critical values. For this reason, additional studies are required for critical precipitation events. Non-linear response, investigated according to regression analysis, reveals optimal zones of plant growth, depending on the total precipitation level before the vegetation peak. For research areas where the dominant species are the turf grasses Stipa ucrainica P. Smirn., S. capillata L., S. lessingiana Trin. & Rupr., Festuca valesiaca Gaudin, Koeleria cristata (L. Pers. the optimal precipitation rates

Changes in Soil Carbon Stocks and Fluxes in Response to Altered Above- and Belowground Vegetation Inputs

Science.gov (United States)

Marañón-Jiménez, S.; Schuetze, C.; Cuntz, M.; García-Quirós, I.; Dienstbach, L.; Schrumpf, M.; Rebmann, C.

2016-12-01

The stimulation of vegetation productivity in response to rising atmospheric CO2 concentrations can potentially compensate climate change feedbacks. However, this will depend on the allocation of C resources of vegetation into biomass production versus root exudates and on the feedbacks with soil microorganisms. These dynamic adjustments of vegetation will result on changes in above- and belowground productivity and on the amount of C exported to root exudates. Consequent alteration of litter and rhizosphere detritus inputs to the soil and their interaction on controlling soil C sequestration capacity has been, however, rarely assessed. We hypothesize that above- and belowground vegetation exert a synergistic control of soil CO2 emissions, and that the activation of soil organic matter mineralization by the addition of labile organic substrates (i.e.: the priming effect) is altered by changes in the amount and in the quality of the carbon inputs. In order to elucidate these questions, different levels of litter addition were implemented on trenched (root exclusion) and non-trenched plots (with roots) in a temperate deciduous forest. Changes in the sensitivity of soil respiration to temperature and moisture were detected by measuring CO2 fluxes continuously at high temporal resolution with automatic chambers, whereas the spatial and seasonal variability was determined using portable chambers. Annual changes in soil carbon and nitrogen stocks provide additional information on the soil carbon sequestration in response to above- and belowground inputs. Both roots and litter inputs significantly enhanced soil CO2 effluxes soon after the implementation of the experiment. We detected synergistic effects between roots and litter inputs on soil CO2 emissions: When roots were present, carbon mineralized in response to litter addition was much higher than the total amount of carbon added in litter (ca. 170 g C m-2 y-1). Preliminary results of this study suggest that labile

Community level offset of rain use- and transpiration efficiency for a heavily grazed ecosystem in inner Mongolia grassland.

Science.gov (United States)

Gao, Ying Z; Giese, Marcus; Gao, Qiang; Brueck, Holger; Sheng, Lian X; Yang, Hai J

2013-01-01

Water use efficiency (WUE) is a key indicator to assess ecosystem adaptation to water stress. Rain use efficiency (RUE) is usually used as a proxy for WUE due to lack of transpiration data. Furthermore, RUE based on aboveground primary productivity (RUEANPP) is used to evaluate whole plant water use because root production data is often missing as well. However, it is controversial as to whether RUE is a reliable parameter to elucidate transpiration efficiency (TE), and whether RUEANPP is a suitable proxy for RUE of the whole plant basis. The experiment was conducted at three differently managed sites in the Inner Mongolia steppe: a site fenced since 1979 (UG79), a winter grazing site (WG) and a heavily grazed site (HG). Site HG had consistent lowest RUEANPP and RUE based on total net primary productivity (RUENPP). RUEANPP is a relatively good proxy at sites UG79 and WG, but less reliable for site HG. Similarly, RUEANPP is good predictor of transpiration efficiency based on aboveground net primary productivity (TEANPP) at sites UG79 and WG but not for site HG. However, if total net primary productivity is considered, RUENPP is good predictor of transpiration efficiency based on total net primary productivity (TENPP) for all sites. Although our measurements indicate decreased plant transpiration and consequentially decreasing RUE under heavy grazing, productivity was relatively compensated for with a higher TE. This offset between RUE and TE was even enhanced under water limited conditions and more evident when belowground net primary productivity (BNNP) was included. These findings suggest that BNPP should be considered when studies fucus on WUE of more intensively used grasslands. The consideration of the whole plant perspective and "real" WUE would partially revise our picture of system performance and therefore might affect the discussion on the C-sequestration and resilience potential of ecosystems.

Mind the Roots: Phenotyping Below-Ground Crop Diversity and Its Influence on Final Yield

Science.gov (United States)

Nieters, C.; Guadagno, C. R.; Lemli, S.; Hosseini, A.; Ewers, B. E.

2017-12-01

Changes in global climate patterns and water regimes are having profound impacts on worldwide crop production. An ever-growing population paired with increasing temperatures and unpredictable periods of severe drought call for accurate modeling of future crop yield. Although novel approaches are being developed in high-throughput, above-ground image phenotyping, the below-ground plant system is still poorly phenotyped. Collection of plant root morphology and hydraulics are needed to inform mathematical models to reliably estimate yields of crops grown in sub-optimal conditions. We used Brassica rapa to inform our model as it is a globally cultivated crop with several functionally diverse cultivars. Specifically, we use 7 different accessions from oilseed (R500 and Yellow Sarson), leafy type (Pac choi and Chinese cabbage), a vegetable turnip, and two Wisconsin Fast Plants (Imb211 and Fast Plant self-compatible), which have shorter life cycles and potentially large differences in allocation to roots. Bi-weekly, we harvested above and below-ground biomass to compare the varieties in terms of carbon allocation throughout their life cycle. Using WinRhizo software, we analyzed root system length and surface area to compare and contrast root morphology among cultivars. Our results confirm that root structural characteristics are crucial to explain plant water use and carbon allocation. The root:shoot ratio reveals a significant (p physiological traits such as gas exchange, chlorophyll content, and chlorophyll a fluorescence. A thorough analysis of the root system will clarify carbon dynamics and hydraulics at the whole-plant level, improving final yield predictions.

Use of innovative groundcovers in Mediterranean afforestations: aerial and belowground effects in hybrid walnut.

Directory of Open Access Journals (Sweden)

Angelo Vitone

2016-11-01

Full Text Available Forest restoration in the Mediterranean area is particularly limited by water scarcity in summer and by weed competition, especially during the first years after establishment. The negative impact of these factors can be mitigated through environmentally friendly and cost-effective techniques which favour root development. This study describes the results of innovative weeding techniques in a reforestation carried out in a former agricultural field in Solsona, NE Spain, under Continental Mediterranean Sub-humid climate conditions. The tested weeding techniques included both novel groundcovers (based on prototypes built on a new biodegradable biopolymer, jute treated with resin and recycled rubber and reference techniques, i.e. herbicide application and polyethylene and commercial biofilm groundcovers. We studied the response of hybrid walnut (Juglans x intermedia to the application of these techniques during the first vegetative period in terms of survival, aerial growth and aboveground and belowground biomass allocation. The innovative groundcovers resulted generally in similar outcomes as the reference techniques with regard to tree survival and growth, and to better results in the case of belowground and, to a lesser extent, total tree biomass. Although preliminary, our results suggest that the tested novel groundcovers, notably the model based on treated jute, represent a promising alternative to plastic mulching and herbicide application in afforestation of agricultural lands in Mediterranean continental conditions. Besides these promising productive results, the novel groundcovers bring together relevant technical and environmental benefits, related to their use (not requiring removal or being reusable and composition, based on biodegradable or recycled materials.

Verification of a primary-to-secondary leaking safety procedure in a nuclear power plant using coloured Petri nets

International Nuclear Information System (INIS)

Nemeth, E.; Bartha, T.; Fazekas, Cs.; Hangos, K.M.

2009-01-01

This paper deals with formal and simulation-based verification methods of a PRImary-to-SEcondary leaking (abbreviated as PRISE) safety procedure. The PRISE safety procedure controls the draining of the contaminated water in a faulty steam generator when a non-compensable leaking from the primary to the secondary circuit occurs. Because of the discrete nature of the verification, a Coloured Petri Net (CPN) representation is proposed for both the procedure and the plant model. We have proved by using a non-model-based strategy that the PRISE safety procedure is safe, there are no dead markings in the state space, and all transitions are live; being either impartial or fair. Further analysis results have been obtained using a model-based verification approach. We created a simple, low dimensional, nonlinear dynamic model of the primary circuit in a VVER-type pressurized water nuclear power plant for the purpose of the model-based verification. This is in contrast to the widely used safety analysis that requires an accurate detailed model. Our model also describes the relevant safety procedures, as well as all of the major leaking-type faults. We propose a novel method to transform this model to a CPN form by discretization. The composed plant and PRISE safety procedure system has also been analysed by simulation using CPN analysis tools. We found by the model-based analysis-using both single and multiple faults-that the PRISE safety procedure initiates the draining when the PRISE event occurs, and no false alarm will be initiated

Combining remote sensing and climatic data to estimate net primary production across Oregon

International Nuclear Information System (INIS)

Law, B.E.; Waring, R.H.

1994-01-01

A range in productivity and climate exists along an east—west transect in Oregon. Remote sensing and climatic data for several of the Oregon Transect Ecosystem Research Project (OTTER) forested sites and neighboring shrub sites were combined to determined whether percentage intercepted photosynthetically active radiation (%IPAR) can be estimated from remotely sensed observations and to evaluate climatic constraints on the ability of vegetation to utilize intercepted of radiation for production. The Thematic Mappers Simulator (TMS) normalized difference vegetation index (NDVI) provided a good linear estimate of %IPAR (R 2 = 0.97). Vegetation intercepted from 24.8% to 99.9% of incident photosynthetically active radiation (PAR), and aboveground net primary production (ANPP) ranged from 53 to 1310 g·m —2 ·yr —1 . The ANPP was linearly related to annual IPAR across sites (R 2 = 0.70). Constraints on the ability of each species to utilize intercepted light, as defined by differential responses to freezing temperatures, drought, and vapor pressure deficit, were quantified from hourly meteorological station measurements near the sites and field physiological measurements. Vegetation could utilize from 30% of intercepted radiation at the eastside semiarid juniper woodland and shrub sites to 97% at the maritime coastal sites. Energy—size efficiency (ϵu), calculated from aboveground production and IPAR modified by the environmental limits, averaged 0.5 g/MJ for the shrub sites and 0.9 g/MJ for the forested sites. (author)

Effects of climate warming on net primary productivity in China during 1961-2010.

Science.gov (United States)

Gu, Fengxue; Zhang, Yuandong; Huang, Mei; Tao, Bo; Guo, Rui; Yan, Changrong

2017-09-01

The response of ecosystems to different magnitudes of climate warming and corresponding precipitation changes during the last few decades may provide an important reference for predicting the magnitude and trajectory of net primary productivity (NPP) in the future. In this study, a process-based ecosystem model, Carbon Exchange between Vegetation, Soil and Atmosphere (CEVSA), was used to investigate the response of NPP to warming at both national and subregional scales during 1961-2010. The results suggest that a 1.3°C increase in temperature stimulated the positive changing trend in NPP at national scale during the past 50 years. Regardless of the magnitude of temperature increase, warming enhanced the increase in NPP; however, the positive trend of NPP decreased when warming exceeded 2°C. The largest increase in NPP was found in regions where temperature increased by 1-2°C, and this rate of increase also contributed the most to the total increase in NPP in China's terrestrial ecosystems. Decreasing precipitation depressed the positive trend in NPP that was stimulated by warming. In northern China, warming depressed the increasing trend of NPP and warming that was accompanied by decreasing precipitation led to negative changing trends in NPP in large parts of northern China, especially when warming exceeded 2°C. However, warming stimulated the increase in NPP until warming was greater than 2°C, and decreased precipitation helped to increase the NPP in southern China.

Petri Nets

Indian Academy of Sciences (India)

In a computer system, for example, typical discrete events ... This project brought out a series of influential reports on Petri net theory in the mid and late ... Technology became a leading centre for Petri net research and from then on, Petri nets ...

EFFECTS OF ELEVATED CO2 ON ROOT FUNCTION AND SOIL RESPIRATION IN A MOJAVE DESERT ECOSYSTEM

Energy Technology Data Exchange (ETDEWEB)

Nowak, Robert S.

2007-12-19

Increases in atmospheric CO{sub 2} concentration during the last 250 years are unequivocal, and CO{sub 2} will continue to increase at least for the next several decades (Houghton et al. 2001, Keeling & Whorf 2002). Arid ecosystems are some of the most important biomes globally on a land surface area basis, are increasing in area at an alarming pace (Dregne 1991), and have a strong coupling with regional climate (Asner & Heidebrecht 2005). These water-limited ecosystems also are predicted to be the most sensitive to elevated CO{sub 2}, in part because they are stressful environments where plant responses to elevated CO{sub 2} may be amplified (Strain & Bazzaz 1983). Indeed, all C{sub 3} species examined at the Nevada Desert FACE Facility (NDFF) have shown increased A{sub net} under elevated CO{sub 2} (Ellsworth et al. 2004, Naumburg et al. 2003, Nowak et al. 2004). Furthermore, increased shoot growth for individual species under elevated CO{sub 2} was spectacular in a very wet year (Smith et al. 2000), although the response in low to average precipitation years has been smaller (Housman et al. 2006). Increases in perennial cover and biomass at the NDFF are consistent with long term trends in the Mojave Desert and elsewhere in the Southwest, indicating C sequestration in woody biomass (Potter et al. 2006). Elevated CO{sub 2} also increases belowground net primary production (BNPP), with average increases of 70%, 21%, and 11% for forests, bogs, and grasslands, respectively (Nowak et al. 2004). Although detailed studies of elevated CO{sub 2} responses for desert root systems were virtually non-existent prior to our research, we anticipated that C sequestration may occur by desert root systems for several reasons. First, desert ecosystems exhibit increases in net photosynthesis and primary production at elevated CO{sub 2}. If large quantities of root litter enter the ecosystem at a time when most decomposers are inactive, significant quantities of carbon may be stored

The relative importance of above- versus belowground competition for tree growth and survival during early succession of a tropical moist forest

NARCIS (Netherlands)

Breugel, van M.; Breugel, van P.; Jansen, P.A.; Martinez-Ramos, M.; Bongers, F.

2012-01-01

Competition between neighboring plants plays a major role in the population dynamics of tree species in the early phases of humid tropical forest succession. We evaluated the relative importance of above- versus below-ground competition during the first years of old-field succession on soil with low

Advancing Understanding of the Role of Belowground Processes in Terrestrial Carbon Sinks trhrough Ground-Penetrating Radar. Final Report

Energy Technology Data Exchange (ETDEWEB)

Day, Frank P. [Old Dominion Univ., Norfolk, VA (United States)

2015-02-06

Coarse roots play a significant role in belowground carbon cycling and will likely play an increasingly crucial role in belowground carbon sequestration as atmospheric CO₂ levels continue to rise, yet they are one of the most difficult ecosystem parameters to quantify. Despite promising results with ground-penetrating radar (GPR) as a nondestructive method of quantifying biomass of coarse roots, this application of GPR is in its infancy and neither the complete potential nor limitations of the technology have been fully evaluated. The primary goals and questions of this study fell into four groups: (1) GPR methods: Can GPR detect change in root biomass over time, differentiate live roots from dead roots, differentiate between coarse roots, fine roots bundled together, and a fine root mat, remain effective with varied soil moisture, and detect shadowed roots (roots hidden below larger roots); (2) CO₂ enrichment study at Kennedy Space Center in Brevard County, Florida: Are there post-fire legacy effects of CO₂ fertilization on plant carbon pools following the end of CO₂application ? (3) Disney Wilderness Study: What is the overall coarse root biomass and potential for belowground carbon storage in a restored longleaf pine flatwoods system? Can GPR effectively quantify coarse roots in soils that are wetter than the previous sites and that have a high percentage of saw palmetto rhizomes present? (4) Can GPR accurately represent root architecture in a three-dimensional model? When the user is familiar with the equipment and software in a setting that minimizes unsuitable conditions, GPR is a relatively precise, non-destructive, useful tool for estimating coarse root biomass. However, there are a number of cautions and guidelines that should be followed to minimize inaccuracies or situations that are untenable for GPR use. GPR appears to be precise as it routinely predicts highly similar values for a given area across multiple

The equivalency between logic Petri workflow nets and workflow nets.

Science.gov (United States)

Wang, Jing; Yu, ShuXia; Du, YuYue

2015-01-01

Logic Petri nets (LPNs) can describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. Logic Petri workflow nets (LPWNs) are proposed based on LPNs in this paper. Process mining is regarded as an important bridge between modeling and analysis of data mining and business process. Workflow nets (WF-nets) are the extension to Petri nets (PNs), and have successfully been used to process mining. Some shortcomings cannot be avoided in process mining, such as duplicate tasks, invisible tasks, and the noise of logs. The online shop in electronic commerce in this paper is modeled to prove the equivalence between LPWNs and WF-nets, and advantages of LPWNs are presented.

The Equivalency between Logic Petri Workflow Nets and Workflow Nets

Science.gov (United States)

Wang, Jing; Yu, ShuXia; Du, YuYue

2015-01-01

Logic Petri nets (LPNs) can describe and analyze batch processing functions and passing value indeterminacy in cooperative systems. Logic Petri workflow nets (LPWNs) are proposed based on LPNs in this paper. Process mining is regarded as an important bridge between modeling and analysis of data mining and business process. Workflow nets (WF-nets) are the extension to Petri nets (PNs), and have successfully been used to process mining. Some shortcomings cannot be avoided in process mining, such as duplicate tasks, invisible tasks, and the noise of logs. The online shop in electronic commerce in this paper is modeled to prove the equivalence between LPWNs and WF-nets, and advantages of LPWNs are presented. PMID:25821845

Long term estimation of carbon dynamic and sequestration for Iranian agro-ecosystem: I- Net primary productivity and annual carbon input for common agricultural crops

Directory of Open Access Journals (Sweden)

M Nassiri Mahalati

2016-05-01

Full Text Available Evaluation of carbon input is one of the most important factors for estimating soil carbon changes and potential for carbon sequestration. To evaluate the net primary productivity (NPP and soil carbon input in agricultural eco-systems of Iran, data for yield, cultivated area, harvest index (HI and shoot /root ratio in different crops including: wheat, barley, maize, cotton, rice, alfalfa and chickpea were obtained for different provinces. Then, allocated carbon to different organs of plant were calculated based on carbon allocation coefficients and finally, the net primary productivity based on carbon (NPPc was calculated. The ratio of NPPc that was annually returned to soil was considered as carbon annual input. The results showed that the maximum amount of NPPc for wheat, barely and alfalfa were obtained in Khazari climate for rice, chickpea and cotton was achieved in warm-wet climate and for maize was gained in warm-dry climate. In all regions of Iran, chickpea had the lowest effect on NPPc and consequently on carbon sequestration. The highest amount of carbon input per unit area among studied crops and different regions were observed in Khazari region for alfalfa whereas, the lowest carbon input per unit area was relation to chickpea in cold region. The lowest gap between actual and potential of carbon sequestration was observed in alfalfa whereas wheat, rice and cotton showed the most gap by 0.4, 0.38 and 0.37, respectively.

Disruption of a belowground mutualism alters interactions between plants and their floral visitors.

Science.gov (United States)

Cahill, James F; Elle, Elizabeth; Smith, Glen R; Shore, Bryon H

2008-07-01

Plants engage in diverse and intimate interactions with unrelated taxa. For example, aboveground floral visitors provide pollination services, while belowground arbuscular mycorrhizal fungi (AMF) enhance nutrient capture. Traditionally in ecology, these processes were studied in isolation, reinforcing the prevailing assumption that these above- and belowground processes were also functionally distinct. More recently, there has been a growing realization that the soil surface is not a barrier to many ecological interactions, particularly those involving plants (who live simultaneously above and below ground). Because of the potentially large impact that mycorrhizae and floral visitors can have on plant performance and community dynamics, we designed an experiment to test whether these multi-species mutualisms were interdependent under field conditions. Using benomyl, a widely used fungicide, we suppressed AMF in a native grassland, measuring plant, fungal, and floral-visitor responses after three years of fungal suppression. AMF suppression caused a shift in the community of floral visitors from large-bodied bees to small-bodied bees and flies, and reduced the total number of floral visits per flowering stem 67% across the 23 flowering species found in the plots. Fungal suppression has species-specific effects on floral visits for the six most common flowering plants in this experiment. Exploratory analyses suggest these results were due to changes in floral-visitor behavior due to altered patch-level floral display, rather than through direct effects of AMF suppression on floral morphology. Our findings indicate that AMF are an important, and overlooked, driver of floral-visitor community structure with the potential to affect pollination services. These results support the growing body of research indicating that interactions among ecological interactions can be of meaningful effect size under natural field conditions and may influence individual performance

[Variation trends of natural vegetation net primary productivity in China under climate change scenario].

Science.gov (United States)

Zhao, Dong-sheng; Wu, Shao-hong; Yin, Yun-he

2011-04-01

Based on the widely used Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ) for climate change study, and according to the features of natural environment in China, the operation mechanism of the model was adjusted, and the parameters were modified. With the modified LPJ model and taking 1961-1990 as baseline period, the responses of natural vegetation net primary productivity (NPP) in China to climate change in 1991-2080 were simulated under the Special Report on Emissions Scenarios (SRES) B2 scenario. In 1961-1990, the total NPP of natural vegetation in China was about 3.06 Pg C a(-1); in 1961-2080, the total NPP showed a fluctuant decreasing trend, with an accelerated decreasing rate. Under the condition of slight precipitation change, the increase of mean air temperature would have definite adverse impact on the NPP. Spatially, the NPP decreased from southeast coast to northwest inland, and this pattern would have less variation under climate change. In eastern China with higher NPP, especially in Northeast China, east of North China, and Loess Plateau, the NPP would mainly have a decreasing trend; while in western China with lower NPP, especially in the Tibetan Plateau and Tarim Basin, the NPP would be increased. With the intensive climate change, such a variation trend of NPP would be more obvious.

Above- and below-ground responses of Calamagrostis purpurea to UV-B radiation and elevated CO{sub 2} under phosphorus limitation

Energy Technology Data Exchange (ETDEWEB)

Bussell, J.S.; Gwynn-Jones, D.; Griffith, G.W.; Scullion, J. (Aberystwyth Univ., IBERS, Wales (United Kingdom))

2012-08-15

UV-B radiation and elevated CO{sub 2} may impact rhizosphere processes through altered below-ground plant resource allocation and root exudation, changes that may have implications for nutrient acquisition. As nutrients limit plant growth in many habitats, their supply may dictate plant response under elevated CO{sub 2}. This study investigated UV-B exposure and elevated CO{sub 2} effects, including interactions, on plant growth, tissue chemistry and rooting responses relating to P acquisition. The sub-arctic grass Calamagrostis purpurea was subjected to UV-B (0 or 3.04 kJ m-2day-1) and CO{sub 2} (ambient 380 or 650 ppmv) treatments in a factorial glasshouse experiment, with sparingly soluble P (0 or 0.152 mg P per plant as FePO{sub 4}) a further factor. It was hypothesized that UV-B exposure and elevated CO{sub 2} would change plant resource allocation, with CO{sub 2} mitigating adverse responses to UV-B exposure and aiding P uptake. Plant biomass and morphology, tissue composition and rhizosphere leachate properties were measured. UV-B directly affected chemical composition of shoots and interacted with CO{sub 2} to give a greater root biomass. Elevated CO{sub 2} altered the composition of both shoots and roots and increased shoot biomass and secondary root length, while leachate pH decreased. Below-ground responses to CO{sub 2} did not affect P acquisition although P limitation progressively reduced leachate pH and increased secondary root length. Although direct plant growth, foliar composition and below-ground nutrient acquisition responses were dominated by CO{sub 2} treatments, UV-B modified these CO{sub 2} responses significantly. These interactions have implications for plant responses to future atmospheric conditions. (Author)

How do general practitioners use 'safety netting' in acutely ill children?

Science.gov (United States)

Bertheloot, Karen; Deraeve, Pieterjan; Vermandere, Mieke; Aertgeerts, Bert; Lemiengre, Marieke; De Sutter, An; Buntinx, Frank; Verbakel, Jan Y

2016-01-01

'Safety netting' advice allows general practitioners (GPs) to cope with diagnostic uncertainty in primary care. It informs patients on 'red flag' features and when and how to seek further help. There is, however, insufficient evidence to support useful choices regarding 'safety netting' procedures. To explore how GPs apply 'safety netting' in acutely ill children in Flanders. We designed a qualitative study consisting of semi-structured interviews with 37 GPs across Flanders. Two researchers performed qualitative analysis based on grounded theory components. Although unfamiliar with the term, GPs perform 'safety netting' in every acutely ill child, guided by their intuition without the use of specific guidelines. They communicate 'red flag' features, expected time course of illness and how and when to re-consult and try to tailor their advice to the context, patient and specific illness. Overall, GPs perceive 'safety netting' as an important element of the consultation, acknowledging personal and parental limitations, such as parents' interpretation of their advice. GPs do not feel a need for any form of support in the near future. GPs apply 'safety netting' intuitively and tailor the content. Further research should focus on the impact of 'safety netting' on morbidity and how the advice is conveyed to parents.

Coloured Petri Nets

DEFF Research Database (Denmark)

Jensen, Kurt

1987-01-01

The author describes a Petri net model, called coloured Petri nets (CP-nets), by means of which it is possible to describe large systems without having to cope with unnecessary details. The author introduces CP-nets and provide a first impression of their modeling power and the suitability...

RadNet Radiological Air Monitoring Network

International Nuclear Information System (INIS)

Scott Telofski, J.; Askren, D.R.; Petko, Ch.M.; Fraass, R.G.

2010-01-01

The United States Environmental Protection Agency operates a national environmental radiation monitoring program called RadNet. RadNet monitors airborne particulates, precipitation, milk, and drinking water for radiation levels. The primary purpose of the original program in the 1950's and 1960's was to collect and analyze samples in various media to assess the effects of radioactive fallout from above-ground nuclear weapon testing. As above-ground testing diminished in the 1970's, the program, especially the air network, became critical in evaluating effects of other types of nuclear incidents, such as the nuclear reactor accident at Chernobyl, as well as monitoring trends in environmental radioactive contamination. The value of rapid data collection subsequent to such incidents led to the consideration of developing air monitors with radiation detectors and telecommunication equipment for real-time radiation measurement. The strengthened United States homeland security posture after 2001 led to production and installation of the current real-time RadNet air monitors. There are now 118 stationary, continuously operating air monitoring stations and 40 mobile air monitors for site specific monitoring. The stationary air monitors include radiation detectors, meteorological sensors, a high-volume air sampler, and communication devices for hourly data transfers. When unusual levels are detected, scientists download a full sodium iodide detector spectrum for analysis. The real-time data collected by RadNet stationary systems permit rapid identification and quantification of airborne nuclides with sufficient sensitivity to provide critical information to help determine protective actions. The data also may help to rapidly refine long-range radioactive plume models and estimate exposure to the population. This paper provides an overview of the airborne particulate monitoring conducted during above-ground nuclear weapon testing, summarizes the uses of data from the program

Measurements and simulation of forest leaf area index and net primary productivity in Northern China.

Science.gov (United States)

Wang, P; Sun, R; Hu, J; Zhu, Q; Zhou, Y; Li, L; Chen, J M

2007-11-01

Large scale process-based modeling is a useful approach to estimate distributions of global net primary productivity (NPP). In this paper, in order to validate an existing NPP model with observed data at site level, field experiments were conducted at three sites in northern China. One site is located in Qilian Mountain in Gansu Province, and the other two sites are in Changbaishan Natural Reserve and Dunhua County in Jilin Province. Detailed field experiments are discussed and field data are used to validate the simulated NPP. Remotely sensed images including Landsat Enhanced Thematic Mapper plus (ETM+, 30 m spatial resolution in visible and near infrared bands) and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER, 15m spatial resolution in visible and near infrared bands) are used to derive maps of land cover, leaf area index, and biomass. Based on these maps, field measured data, soil texture and daily meteorological data, NPP of these sites are simulated for year 2001 with the boreal ecosystem productivity simulator (BEPS). The NPP in these sites ranges from 80 to 800 gCm(-2)a(-1). The observed NPP agrees well with the modeled NPP. This study suggests that BEPS can be used to estimate NPP in northern China if remotely sensed images of high spatial resolution are available.

Climate dependence of the CO2 fertilization effect on terrestrial net primary production

International Nuclear Information System (INIS)

Alexandrov, G.A.; Yamagata, Y.; Oikawa, T.

2003-01-01

The quantitative formulation of the fertilization effect of CO 2 enrichment on net primary production (NPP) introduced by Keeling and Bacastow in 1970s (known as Keeling's formula) has been recognized as a summary of experimental data and has been used in various assessments of the industrial impact on atmospheric chemistry. Nevertheless, the magnitude of the formula's key coefficient, the so-called growth factor, has remained open to question. Some of the global carbon cycle modelers avoid this question by tuning growth factor and choosing the value that fits the observed course of atmospheric CO 2 changes. However, for mapping terrestrial sinks induced by the CO 2 fertilization effect one needs a geographical pattern of the growth factor rather than its globally averaged value. The earlier approach to this problem involved formulating the climate dependence of the growth factor and the derivation of its global pattern from climatic variables (whose geographical distribution is known). We use a process-based model (TsuBiMo) for this purpose and derive the values of growth factor for major biomes for comparison our approach with the earlier studies. Contrary to the earlier prevailing opinion, TsuBiMo predicts that these values decrease with mean annual temperature (excluding biomes of limited water supply). We attribute this result to the effect of light limitation caused by mutual shading inside a canopy, which was considered earlier as unimportant, and conclude that current hypotheses about CO 2 fertilization effect (and thus projections of the related carbon sink) are very sensitive to the choice of driving forces taken into account

Age-Related Deterioration of Perineuronal Nets in the Primary Auditory Cortex of Mice

Directory of Open Access Journals (Sweden)

Dustin H Brewton

2016-11-01

Full Text Available Age-related changes in inhibitory neurotransmission in sensory cortex may underlie deficits in sensory function. Perineuronal nets (PNNs are extracellular matrix components that ensheath some inhibitory neurons, particularly parvalbumin positive (PV+ interneurons. PNNs may protect PV+ cells from oxidative stress and help establish their rapid spiking properties. Although PNN expression has been well characterized during development, possible changes in aging sensory cortex have not been investigated. Here we tested the hypothesis that PNN+, PV+ and PV/PNN co-localized cell densities decline with age in the primary auditory cortex (A1. This hypothesis was tested using immunohistochemistry in two strains of mice (C57BL/6 and CBA/CaJ with different susceptibility to age-related hearing loss and at three different age ranges (1-3, 6-8 and 14-24 months old. We report that PNN+ and PV/PNN co-localized cell densities decline significantly with age in A1 in both mouse strains. In the PNN+ cells that remain in the old group, the intensity of PNN staining is reduced in the C57 strain, but not the CBA strain. PV+ cell density also declines only in the C57, but not the CBA, mouse suggesting a potential exacerbation of age-effects by hearing loss in the PV/PNN system. Taken together, these data suggest that PNN deterioration may be a key component of altered inhibition in the aging sensory cortex, that may lead to altered synaptic function, susceptibility to oxidative stress and processing deficits.

Estimating regional terrestrial carbon fluxes for the Australian continent using a multiple-constraint approach. I. Using remotely sensed data and ecological observations of net primary production

International Nuclear Information System (INIS)

Ying Ping Wang; Barrett, Damian J.

2003-01-01

We have developed a modelling framework that synthesizes various types of field measurements at different spatial and temporal scales. We used this modelling framework to estimate monthly means and their standard deviations of gross photosynthesis, total ecosystem production, net primary production (NPP) and net ecosystem production (NEP) for eight regions of the Australian continent between 1990 and 1998. Annual mean NPP of the Australian continent varied between 800 and 1100 Mt C/yr between 1990 and 1998, with a coefficient of variation that is defined as the ratio of standard deviation and mean between 0.24 and 0.34. The seasonal variation of NPP for the whole continent varied between 50 and 110 Mt C/month with two maxima, one in the autumn and another in the spring. NEP was most negative in the winter (a carbon sink) and was most positive (a carbon source) in the summer. However, the coefficient of variation of monthly mean NEP was very large (> 4), and consequently confidence in the predicted net carbon fluxes for any month in the period 1990-1998 for the whole continent was very low. A companion paper will apply atmospheric inverse technique to measurements of CO 2 concentration to further constrain the continental carbon cycle and reduce uncertainty in estimated mean monthly carbon fluxes

Spatiotemporal changes in vegetation net primary productivity in the arid region of Northwest China, 2001 to 2012

Science.gov (United States)

Li, Zhen; Pan, Jinghu

2018-03-01

Net primary productivity (NPP) is recognized as an important index of ecosystem conditions and a key variable of the terrestrial carbon cycle. It also represents the comprehensive effects of climate change and anthropogenic activity on terrestrial vegetation. In this study, the temporal-spatial pattern of NPP for the period 2001-2012 was analyzed using a remote sensing-based carbon model (i.e., the Carnegie-Ames-Stanford Approach, CASA) in addition to other methods, such as linear trend analysis, standard deviation, and the Hurst index. Temporally, NPP showed a significant increasing trend for the arid region of Northwest China (ARNC), with an annual increase of 2.327 g C. Maximum and minimum productivity values appeared in July and December, respectively. Spatially, the NPP was relatively stable in the temperate and warm-temperate desert regions of Northwest China, while temporally, it showed an increasing trend. However, some attention should be given to the northwestern warm-temperate desert region, where there is severe continuous degradation and only a slight improvement trend.

Links between belowground and aboveground resource-related traits reveal species growth strategies that promote invasive advantages.

Science.gov (United States)

Smith, Maria S; Fridley, Jason D; Goebel, Marc; Bauerle, Taryn L

2014-01-01

Belowground processes are rarely considered in comparison studies of native verses invasive species. We examined relationships between belowground fine root production and lifespan, leaf phenology, and seasonal nitrogen dynamics of Lonicera japonica (non-native) versus L. sempervirens (native) and Frangula alnus (non-native) versus Rhamnus alnifolia (native), over time. First and second order fine roots were monitored from 2010 to 2012 using minirhizotron technology and rhizotron windows. 15N uptake of fine roots was measured across spring and fall seasons. Significant differences in fine root production across seasons were seen between Lonicera species, but not between Frangula and Rhamnus, with both groups having notable asynchrony in regards to the timing of leaf production. Root order and the number of root neighbors at the time of root death were the strongest predictors of root lifespan of both species pairs. Seasonal 15N uptake was higher in spring than in the fall, which did not support the need for higher root activity to correspond with extended leaf phenology. We found higher spring 15N uptake in non-native L. japonica compared to native L. sempervirens, although there was no difference in 15N uptake between Frangula and Rhamnus species. Our findings indicate the potential for fast-growing non-native Lonicera japonica and Frangula alnus to outcompete native counterparts through differences in biomass allocation, root turnover, and nitrogen uptake, however evidence that this is a general strategy of invader dominance is limited.

Links between belowground and aboveground resource-related traits reveal species growth strategies that promote invasive advantages.

Directory of Open Access Journals (Sweden)

Maria S Smith

Full Text Available Belowground processes are rarely considered in comparison studies of native verses invasive species. We examined relationships between belowground fine root production and lifespan, leaf phenology, and seasonal nitrogen dynamics of Lonicera japonica (non-native versus L. sempervirens (native and Frangula alnus (non-native versus Rhamnus alnifolia (native, over time. First and second order fine roots were monitored from 2010 to 2012 using minirhizotron technology and rhizotron windows. 15N uptake of fine roots was measured across spring and fall seasons. Significant differences in fine root production across seasons were seen between Lonicera species, but not between Frangula and Rhamnus, with both groups having notable asynchrony in regards to the timing of leaf production. Root order and the number of root neighbors at the time of root death were the strongest predictors of root lifespan of both species pairs. Seasonal 15N uptake was higher in spring than in the fall, which did not support the need for higher root activity to correspond with extended leaf phenology. We found higher spring 15N uptake in non-native L. japonica compared to native L. sempervirens, although there was no difference in 15N uptake between Frangula and Rhamnus species. Our findings indicate the potential for fast-growing non-native Lonicera japonica and Frangula alnus to outcompete native counterparts through differences in biomass allocation, root turnover, and nitrogen uptake, however evidence that this is a general strategy of invader dominance is limited.

Belowground neighbor perception in Arabidopsis thaliana studied by transcriptome analysis: roots of Hieracium pilosella cause biotic stress

Directory of Open Access Journals (Sweden)

Christoph eSchmid

2013-08-01

Full Text Available Root-root interactions are much more sophisticated than previously thought, yet the mechanisms of belowground neighbor perception remain largely obscure. Genome-wide transcriptome analyses allow detailed insight into plant reactions to environmental cues.A root interaction trial was set up to explore both morphological and whole genome transcriptional responses in roots of Arabidopsis thaliana in the presence or absence of an inferior competitor, Hieracium pilosella.Neighbor perception was indicated by Arabidopsis roots predominantly growing away from the neighbor (segregation, while solitary plants placed more roots towards the middle of the pot. Total biomass remained unaffected. Database comparisons in transcriptome analysis revealed considerable similarity between Arabidopsis root reactions to neighbors and reactions to pathogens. Detailed analyses of the functional category ‘biotic stress’ using MapMan tools found the sub-category ‘pathogenesis-related proteins’ highly significantly induced. A comparison to a study on intraspecific competition brought forward a core of genes consistently involved in reactions to neighbor roots.We conclude that beyond resource depletion roots perceive neighboring roots or their associated microorganisms by a relatively uniform mechanism that involves the strong induction of pathogenesis-related proteins. In an ecological context the findings reveal that belowground neighbor detection may occur independently of resource depletion, allowing for a time advantage for the root to prepare for potential interactions.

Depression of belowground respiration is more pronounced than enhancement of photosynthesis during the first year after nitrogen fertilization of a mature Pacific Northwest Douglas-fir forest

Science.gov (United States)

Chen, B.; Black, T. A.; Jassal, R.; Nesic, Z.; Bruemmer, C.

2008-05-01

Nitrogen (N) additions to forest have shown variable effects on both respiration and photosynthesis. With increasing rates of anthropogenic N deposition, there is a strong need to understand the ecosystem response to N inputs. We investigated how N fertilization affects the ecosystem carbon (C) balance of a 57-year-old coast Douglas-fir stand in British Columbia, Canada, based on eddy-covariance (EC) and soil-chamber (fertilized and control plots) measurements and process-based modeling. The stand was fertilized by helicopter with urea at 200 kg N ha-1 in January 2007. A land surface model (Ecosystem Atmosphere Simulation Scheme, EASS) was combined with an ecosystem model (Boreal Ecosystem Productivity Simulator, BEPS) and a coupled C and N subroutine was incorporated into the integrated EASS-BEPS model in this study. This half-hourly time step model was run continuously for the period from 2001 to 2007 in two scenarios: with and without fertilization. Modeled C fluxes without fertilization [net ecosystem productivity (NEP), gross primary productivity (GPP), ecosystem respiration (Re) and belowground respiration (Rs)] agreed well with EC and soil chamber measurements over diurnal, seasonal and annual time scales for 2001 to 2006; while simulated NEP, GPP, Re and Rs with fertilization reasonably followed EC and chamber measurements in 2007 (545 vs. 520, 2163 vs. 2155, 1618 vs. 1635, and 920 vs. 906 g C m-2 yr-1, respectively). Comparison of EC-determined C fluxes in 2007 with model simulations without fertilization suggests that annual Re decreased by 6.7% (1635 vs. 1752 g C m-2), gross primary productivity (GPP) increased by 6.8% (2155 vs. 2017 g C m-2), and annual NEP increased by 96.2% (520 vs. 265 g C m-2) due to fertilization. The modeled reduction in Rs (9.6%, comparing modeled values without and with fertilization: 1008 vs. 920 g C m-2 yr-1) is consistent with that measured using the soil chambers (~11.5%, comparing CO2 effluxes from control and fertilized

Application of Computer-Aided Tomography (CT) Technology to Visually Compare Belowground Components of Salt Marshes in Jamaica Bay and Long Island, New York

Science.gov (United States)

Using CT imaging, we found that rapidly deteriorating marshes in Jamaica Bay had significantly less belowground mass and abundance of coarse roots and rhizomes at depth (< 10 cm) compared to more stable areas in the Jamaica Bay Estuary. In addition, the rhizome diameters and pea...

Cardenolides, induced responses, and interactions between above- and belowground herbivores of milkweed (Asclepias spp.).

Science.gov (United States)

Rasmann, Sergio; Agrawal, Anurag A; Cook, Susan C; Erwin, Alexis C

2009-09-01

Theory has long predicted allocation patterns for plant defense against herbivory, but only recently have both above- and belowground plant defenses been considered simultaneously. Milkweeds in the genus Asclepias are a classic chemically defended clade of plants with toxic cardenolides (cardiac glycosides) and pressurized latex employed as anti-herbivore weapons. Here we combine a comparative approach to investigate broadscale patterns in allocation to root vs. shoot defenses across species with a species-specific experimental approach to identify the consequences of defense allocational shifts on a specialist herbivore. Our results show phylogenetic conservatism for inducibility of shoot cardenolides by an aboveground herbivore, with only four closely related tropical species showing significant induction; the eight temperate species examined were not inducible. Allocation to root and shoot cardenolides was positively correlated across species, and this relationship was maintained after accounting for phylogenetic nonindependence. In contrast to long-standing theoretical predictions, we found no evidence for a trade-off between constitutive and induced cardenolides; indeed the two were positively correlated across species in both roots and shoots. Finally, specialist root and shoot herbivores of common milkweed (A. syriaca) had opposing effects on latex production, and these effects had consequences for caterpillar growth consistent with latex providing resistance. Although cardenolides were not affected by our treatments, A. syriaca allocated 40% more cardenolides to shoots over roots. We conclude that constitutive and inducible defenses are not trading off across plant species, and shoots of Asclepias are more inducible than roots. Phylogenetic conservatism cannot explain the observed patterns of cardenolide levels across species, but inducibility per se was conserved in a tropical clade. Finally, given that above- and belowground herbivores can systemically

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

Science.gov (United States)

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

2014-12-01

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

Application of deconvolution interferometry with both Hi-net and KiK-net data

Science.gov (United States)

Nakata, N.

2013-12-01

Application of deconvolution interferometry to wavefields observed by KiK-net, a strong-motion recording network in Japan, is useful for estimating wave velocities and S-wave splitting in the near surface. Using this technique, for example, Nakata and Snieder (2011, 2012) found changed in velocities caused by Tohoku-Oki earthquake in Japan. At the location of the borehole accelerometer of each KiK-net station, a velocity sensor is also installed as a part of a high-sensitivity seismograph network (Hi-net). I present a technique that uses both Hi-net and KiK-net records for computing deconvolution interferometry. The deconvolved waveform obtained from the combination of Hi-net and KiK-net data is similar to the waveform computed from KiK-net data only, which indicates that one can use Hi-net wavefields for deconvolution interferometry. Because Hi-net records have a high signal-to-noise ratio (S/N) and high dynamic resolution, the S/N and the quality of amplitude and phase of deconvolved waveforms can be improved with Hi-net data. These advantages are especially important for short-time moving-window seismic interferometry and deconvolution interferometry using later coda waves.

Exploring the Influence of Topography on Belowground C Processes Using a Coupled Hydrologic-Biogeochemical Model

Science.gov (United States)

Shi, Y.; Davis, K. J.; Eissenstat, D. M.; Kaye, J. P.; Duffy, C.; Yu, X.; He, Y.

2014-12-01

Belowground carbon processes are affected by soil moisture and soil temperature, but current biogeochemical models are 1-D and cannot resolve topographically driven hill-slope soil moisture patterns, and cannot simulate the nonlinear effects of soil moisture on carbon processes. Coupling spatially-distributed physically-based hydrologic models with biogeochemical models may yield significant improvements in the representation of topographic influence on belowground C processes. We will couple the Flux-PIHM model to the Biome-BGC (BBGC) model. Flux-PIHM is a coupled physically-based land surface hydrologic model, which incorporates a land-surface scheme into the Penn State Integrated Hydrologic Model (PIHM). The land surface scheme is adapted from the Noah land surface model. Because PIHM is capable of simulating lateral water flow and deep groundwater, Flux-PIHM is able to represent the link between groundwater and the surface energy balance, as well as the land surface heterogeneities caused by topography. The coupled Flux-PIHM-BBGC model will be tested at the Susquehanna/Shale Hills critical zone observatory (SSHCZO). The abundant observations, including eddy covariance fluxes, soil moisture, groundwater level, sap flux, stream discharge, litterfall, leaf area index, above ground carbon stock, and soil carbon efflux, make SSHCZO an ideal test bed for the coupled model. In the coupled model, each Flux-PIHM model grid will couple a BBGC cell. Flux-PIHM will provide BBGC with soil moisture and soil temperature information, while BBGC provides Flux-PIHM with leaf area index. Preliminary results show that when Biome- BGC is driven by PIHM simulated soil moisture pattern, the simulated soil carbon is clearly impacted by topography.

Characterizing uncertainties in recent trends of global terrestrial net primary production through ensemble modeling

Science.gov (United States)

Wang, W.; Hashimoto, H.; Ganguly, S.; Votava, P.; Nemani, R. R.; Myneni, R. B.

2010-12-01

Large uncertainties exist in our understanding of the trends and variability in global net primary production (NPP) and its controls. This study attempts to address this question through a multi-model ensemble experiment. In particular, we drive ecosystem models including CASA, LPJ, Biome-BGC, TOPS-BGC, and BEAMS with a long-term climate dataset (i.e., CRU-NCEP) to estimate global NPP from 1901 to 2009 at a spatial resolution of 0.5 x 0.5 degree. We calculate the trends of simulated NPP during different time periods and test their sensitivities to climate variables of solar radiation, air temperature, precipitation, vapor pressure deficit (VPD), and atmospheric CO2 levels. The results indicate a large diversity among the simulated NPP trends over the past 50 years, ranging from nearly no trend to an increasing trend of ~0.1 PgC/yr. Spatial patterns of the NPP generally show positive trends in boreal forests, induced mainly by increasing temperatures in these regions; they also show negative trends in the tropics, although the spatial patterns are more diverse. These diverse trends result from different climatic sensitivities of NPP among the tested models. Depending the ecological processes (e.g., photosynthesis or respiration) a model emphasizes, it can be more or less responsive to changes in solar radiation, temperatures, water, or atmospheric CO2 levels. Overall, these results highlight the limit of current ecosystem models in simulating NPP, which cannot be easily observed. They suggest that the traditional single-model approach is not ideal for characterizing trends and variability in global carbon cycling.

Net Neutrality

DEFF Research Database (Denmark)

Savin, Andrej

2017-01-01

Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else.......Repealing “net neutrality” in the US will have no bearing on Internet freedom or security there or anywhere else....

Annotating Coloured Petri Nets

DEFF Research Database (Denmark)

Lindstrøm, Bo; Wells, Lisa Marie

2002-01-01

Coloured Petri nets (CP-nets) can be used for several fundamentally different purposes like functional analysis, performance analysis, and visualisation. To be able to use the corresponding tool extensions and libraries it is sometimes necessary to include extra auxiliary information in the CP......-net. An example of such auxiliary information is a counter which is associated with a token to be able to do performance analysis. Modifying colour sets and arc inscriptions in a CP-net to support a specific use may lead to creation of several slightly different CP-nets – only to support the different uses...... of the same basic CP-net. One solution to this problem is that the auxiliary information is not integrated into colour sets and arc inscriptions of a CP-net, but is kept separately. This makes it easy to disable this auxiliary information if a CP-net is to be used for another purpose. This paper proposes...

Quantifying Human Appropriated Net Primary Productivity (HANPP) in a Ghanaian Cocoa System

Science.gov (United States)

Morel, A.; Adu-Bredu, S.; Adu Sasu, M.; Ashley Asare, R.; Boyd, E.; Hirons, M. A.; Malhi, Y.; Mason, J.; Norris, K.; Robinson, E. J. Z.; McDermott, C. L.

2015-12-01

Ghana is the second largest producer of cocoa (Theobroma cacoa), exporting approximately 18 percent of global volumes. These cocoa farms are predominantly small-scale, ranging in size from 2-4 hectares (ha). Traditionally, the model of cocoa expansion in Ghana relied on clearing new areas of forest and establishing a farm under remnant forest trees. This is increasingly less practical due to few unprotected forest areas remaining and management practices favoring close to full sun cocoa to maximize short-term yields. This study is part of a larger project, ECOLMITS, which is an interdisciplinary, ESPA-funded[1] initiative exploring the ecological limits of ecosystem system services (ESS) for alleviating poverty in small-scale agroforestry systems. The ecological study plots are situated within and around the Kakum National Forest, a well-protected, moist-evergreen forest of the Lower Guinea Forest region. Net primary productivity (NPP) is a measure of the rate at which carbon dioxide (CO2) is incorporated into plant tissues (e.g. canopy, stem and root). For this study, NPP was monitored in situ using methods developed by the Global Environmental Monitoring Network (GEM, http://gem.tropicalforests.ox.ac.uk/). By comparing NPP measured in intact forest and farms, the human appropriated NPP (HANPP) of this system can be estimated. The forest measures provide the "potential" NPP of the region, and then the reduction in NPP for farm plots is calculated for both land-cover change (HANPPLUC) and cocoa harvesting (HANPPHARV). The results presented are of the first year of NPP measurements across the cocoa landscape, including measurements from intact forest, logged forest and cocoa farms across a shade gradient and located at varying distances from the forest edge (e.g. 100 m, 500 m, 1 km and 5 km). These measures will have implications for carbon sequestration potential over the region and long-term sustainability of the Ghanaian cocoa sector. [1] Ecosystem Services for

Analysis of physical flows in primary commodity trade. A case study in China

International Nuclear Information System (INIS)

Ma, Tao; Li, Bo; Fang, Changming; Zhao, Bin; Luo, Yiqi; Chen, Jiakuan

2006-01-01

How globalization and international trade affect sustainable development and environment has attracted worldwide attention. Associated with the import and export of primary commodities, ecologically important materials have been exchanged among regions and countries. China, having the largest population in the world and the highest economic growth rate in last decades, may have an important influence on global sustainable development through the trade of primary commodities. Using the data from Almanac of China's Foreign Economic Relations and Trade, we analyzed material flows in the trade of primary commodity in China from 1950 to 2001. Our analysis shows that: (1) China has turned from a net exporter of primary commodities to a net importer; (2) minerals and fuels have been the major imports of primary commodities since 1992, just as well as foods and minerals did in 1980s; (3) most of the net imported primary commodities come from Oceania, Africa and Latin America. (author)

NetSig

DEFF Research Database (Denmark)

Horn, Heiko; Lawrence, Michael S; Chouinard, Candace R

2018-01-01

Methods that integrate molecular network information and tumor genome data could complement gene-based statistical tests to identify likely new cancer genes; but such approaches are challenging to validate at scale, and their predictive value remains unclear. We developed a robust statistic (Net......Sig) that integrates protein interaction networks with data from 4,742 tumor exomes. NetSig can accurately classify known driver genes in 60% of tested tumor types and predicts 62 new driver candidates. Using a quantitative experimental framework to determine in vivo tumorigenic potential in mice, we found that Net......Sig candidates induce tumors at rates that are comparable to those of known oncogenes and are ten-fold higher than those of random genes. By reanalyzing nine tumor-inducing NetSig candidates in 242 patients with oncogene-negative lung adenocarcinomas, we find that two (AKT2 and TFDP2) are significantly amplified...

Below-ground plant parts emit herbivore-induced volatiles: olfactory responses of a predatory mite to tulip bulbs infested by rust mites.

Science.gov (United States)

Aratchige, N S; Lesna, I; Sabelis, M W

2004-01-01

Although odour-mediated interactions among plants, spider mites and predatory mites have been extensively studied above-ground, belowground studies are in their infancy. In this paper, we investigate whether feeding by rust mites (Aceria tulipae) cause tulip bulbs to produce odours that attract predatory mites (Neoseiulus cucumeris). Since our aim was to demonstrate such odours and not their relevance under soil conditions, the experiments were carried out using a classic Y-tube olfactometer in which the predators moved on a Y-shaped wire in open air. We found that food-deprived female predators can discriminate between odours from infested bulbs and odours from uninfested bulbs or artificially wounded bulbs. No significant difference in attractiveness to predators was found between clean bulbs and bulbs either wounded 30 min or 3 h before the experiment. These results indicate that it may not be simply the wounding of the bulbs, but rather the feeding by rust mites, which causes the bulb to release odours that attract N. cucumeris. Since bulbs are belowground plant structures, the olfactometer results demonstrate the potential for odour-mediated interactions in the soil. However, their importance in the actual soil medium remains to be demonstrated.

Aboveground and belowground legacies of native Sami land use on boreal forest in northern Sweden 100 years after abandonment.

Science.gov (United States)

Freschet, Grégoire T; Ostlund, Lars; Kichenin, Emilie; Wardle, David A

2014-04-01

Human activities that involve land-use change often cause major transformations to community and ecosystem properties both aboveground and belowground, and when land use is abandoned, these modifications can persist for extended periods. However, the mechanisms responsible for rapid recovery vs. long-term maintenance of ecosystem changes following abandonment remain poorly understood. Here, we examined the long-term ecological effects of two remote former settlements, regularly visited for -300 years by reindeer-herding Sami and abandoned -100 years ago, within an old-growth boreal forest that is considered one of the most pristine regions in northern Scandinavia. These human legacies were assessed through measurements of abiotic and biotic soil properties and vegetation characteristics at the settlement sites and at varying distances from them. Low-intensity land use by Sami is characterized by the transfer of organic matter towards the settlements by humans and reindeer herds, compaction of soil through trampling, disappearance of understory vegetation, and selective cutting of pine trees for fuel and construction. As a consequence, we found a shift towards early successional plant species and a threefold increase in soil microbial activity and nutrient availability close to the settlements relative to away from them. These changes in soil fertility and vegetation contributed to 83% greater total vegetation productivity, 35% greater plant biomass, and 23% and 16% greater concentrations of foliar N and P nearer the settlements, leading to a greater quantity and quality of litter inputs. Because decomposer activity was also 40% greater towards the settlements, soil organic matter cycling and nutrient availability were further increased, leading to likely positive feedbacks between the aboveground and belowground components resulting from historic land use. Although not all of the activities typical of Sami have left visible residual traces on the ecosystem after

Partitioning of the net CO2 exchange using an automated chamber system reveals plant phenology as key control of production and respiration fluxes in a boreal peatland.

Science.gov (United States)

Järveoja, Järvi; Nilsson, Mats B; Gažovič, Michal; Crill, Patrick M; Peichl, Matthias

2018-04-30

The net ecosystem CO 2 exchange (NEE) drives the carbon (C) sink-source strength of northern peatlands. Since NEE represents a balance between various production and respiration fluxes, accurate predictions of its response to global changes require an in depth understanding of these underlying processes. Currently, however, detailed information of the temporal dynamics as well as the separate biotic and abiotic controls of the NEE component fluxes is lacking in peatland ecosystems. In this study, we address this knowledge gap by using an automated chamber system established across natural and trenching-/vegetation removal plots to partition NEE into its production (i.e. gross and net primary production; GPP and NPP) and respiration (i.e. ecosystem, heterotrophic and autotrophic respiration; ER, Rh and Ra) fluxes in a boreal peatland in northern Sweden. Our results showed that daily NEE patterns were driven by GPP while variations in ER were governed by Ra rather than Rh. Moreover, we observed pronounced seasonal shifts in the Ra/Rh and above-/belowground NPP ratios throughout the main phenological phases. Generalized linear model analysis revealed that the greenness index derived from digital images (as a proxy for plant phenology) was the strongest control of NEE, GPP and NPP while explaining considerable fractions also in the variations of ER and Ra. In addition, our data exposed greater temperature sensitivity of NPP compared to Rh resulting in enhanced C sequestration with increasing temperature. Overall, our study suggests that the temporal patterns in NEE and its component fluxes are tightly coupled to vegetation dynamics in boreal peatlands and thus challenges previous studies that commonly identify abiotic factors as key drivers. These findings further emphasize the need for integrating detailed information on plant phenology into process-based models to improve predictions of global change impacts on the peatland C cycle. This article is protected by

Learning Visual Basic NET

CERN Document Server

Liberty, Jesse

2009-01-01

Learning Visual Basic .NET is a complete introduction to VB.NET and object-oriented programming. By using hundreds of examples, this book demonstrates how to develop various kinds of applications--including those that work with databases--and web services. Learning Visual Basic .NET will help you build a solid foundation in .NET.

Nuclear imaging of neuroendocrine tumors with unknown primary: why, when and how?

Energy Technology Data Exchange (ETDEWEB)

Santhanam, Prasanna; Chandramahanti, Sangeeta [Marshall University, Section of Endocrinology, Department of Internal Medicine, Joan C Edwards School of Medicine, Huntington, WV (United States); Kroiss, Alexander [Medical University Innsbruck, Department of Nuclear Medicine, Innsbruck (Austria); Yu, Run [Cedars-Sinai Medical Center, Division of Endocrinology and Carcinoid and Neuroendocrine Tumor Center, Los Angeles, CA (United States); Ruszniewski, Philippe [Beaujon Hospital and Paris-Diderot University, Department of Gastroenterology-Pancreatology, Paris (France); Kumar, Rakesh [All India Institute of Medical Sciences, Diagnostic Nuclear Medicine Division, Department of Nuclear Medicine, New Delhi (India); Taieb, David [Aix-Marseille University, Department of Nuclear Medicine, La Timone University Hospital, Marseille (France); Institut Paoli-Calmettes, Inserm UMR1068 Marseille Cancerology Research Center, Marseille (France); Aix-Marseille University, European Center for Research in Medical Imaging, Marseille (France)

2015-03-13

Neuroendocrine tumors (NETs) with unknown primary (CUP-NET) are associated with a poor prognosis (10-year survival 22 %), grade 1 and 2 NETs having a more favorable outcome than grade 3 (also called carcinoma). There is evidence that an effort should be made to localize the primary tumor even in the presence of metastasis because resection of the primary tumor(s) may improve disease-free and overall survival, and because the choice of chemotherapeutic agent depends on the location of the primary tumor. Localization of the tumors remains challenging and often relies on a combination of radiological, endoscopic and functional imaging. The functional imaging protocol for evaluation of these patients has historically relied on somatostatin receptor scintigraphy (SRS). However, the sensitivity and specificity of SRS may be unsatisfactory, especially for NETs of midgut origin. Newer PET radiotracers such as {sup 68}Ga-labeled somatostatin analogs ({sup 68}Ga-DOTA-SSTa) and {sup 18}F-DOPA have shown promise. In direct comparisons between {sup 68}Ga-DOTA-SSTa PET/CT and {sup 99m}Tc-HYNIC-octreotide/{sup 111}In-pentetreotide SPECT(/CT), {sup 68}Ga-DOTA-SSTa performed better than other techniques, giving a compelling reason for switching from SPECT/CT to PET/CT imaging. {sup 18}F-DOPA performs better than SRS and CT in well-differentiated NETs of the small intestine. For detecting pancreatic NETs, the high background uptake of {sup 18}F-DOPA by the normal exocrine pancreas can be somewhat overcome by pretreatment with carbidopa. We have suggested a protocol in which SRS is replaced by one of the two agents (preferably with {sup 68}Ga-DOTA-SSTa, alternatively {sup 18}F-DOPA) as first-line nuclear tracer for detection of CUP-NET in patients with well-differentiated NETs and {sup 18}F-FDG PET/CT may be an additional diagnostic test for poorly differentiated tumors and for prognostication. In the near future, it is expected that patients with CUP-NET will benefit from newly

Nuclear imaging of neuroendocrine tumors with unknown primary: why, when and how?

International Nuclear Information System (INIS)

Santhanam, Prasanna; Chandramahanti, Sangeeta; Kroiss, Alexander; Yu, Run; Ruszniewski, Philippe; Kumar, Rakesh; Taieb, David

2015-01-01

Neuroendocrine tumors (NETs) with unknown primary (CUP-NET) are associated with a poor prognosis (10-year survival 22 %), grade 1 and 2 NETs having a more favorable outcome than grade 3 (also called carcinoma). There is evidence that an effort should be made to localize the primary tumor even in the presence of metastasis because resection of the primary tumor(s) may improve disease-free and overall survival, and because the choice of chemotherapeutic agent depends on the location of the primary tumor. Localization of the tumors remains challenging and often relies on a combination of radiological, endoscopic and functional imaging. The functional imaging protocol for evaluation of these patients has historically relied on somatostatin receptor scintigraphy (SRS). However, the sensitivity and specificity of SRS may be unsatisfactory, especially for NETs of midgut origin. Newer PET radiotracers such as 68 Ga-labeled somatostatin analogs ( 68 Ga-DOTA-SSTa) and 18 F-DOPA have shown promise. In direct comparisons between 68 Ga-DOTA-SSTa PET/CT and 99m Tc-HYNIC-octreotide/ 111 In-pentetreotide SPECT(/CT), 68 Ga-DOTA-SSTa performed better than other techniques, giving a compelling reason for switching from SPECT/CT to PET/CT imaging. 18 F-DOPA performs better than SRS and CT in well-differentiated NETs of the small intestine. For detecting pancreatic NETs, the high background uptake of 18 F-DOPA by the normal exocrine pancreas can be somewhat overcome by pretreatment with carbidopa. We have suggested a protocol in which SRS is replaced by one of the two agents (preferably with 68 Ga-DOTA-SSTa, alternatively 18 F-DOPA) as first-line nuclear tracer for detection of CUP-NET in patients with well-differentiated NETs and 18 F-FDG PET/CT may be an additional diagnostic test for poorly differentiated tumors and for prognostication. In the near future, it is expected that patients with CUP-NET will benefit from newly developed PET approaches (radiopharmaceuticals) and

Carbon dynamics in an Imperata grassland in Northeast India

Directory of Open Access Journals (Sweden)

Amrabati Thokchom

2016-01-01

Full Text Available Carbon stocks and soil CO2 flux were assessed in an Imperata cylindrica grassland of Manipur, Northeast India. Carbon stocks in the vegetative components were estimated to be 11.17 t C/ha and soil organic carbon stocks were 55.94 t C/ha to a depth of 30 cm. The rates of carbon accumulation in above-ground and below-ground biomass were estimated to be 11.85 t C/ha/yr and 11.71 t C/ha/yr, respectively. Annual soil CO2 flux was evaluated as 6.95 t C/ha and was highly influenced by soil moisture, soil temperature and soil organic carbon as well as by C stocks in above-ground biomass. Our study on the carbon budget of the grassland ecosystem revealed that annually 23.56 t C/ha was captured by the vegetation through photosynthesis, and 6.95 t C/ha was returned to the atmosphere through roots and microbial respiration, with a net balance of 16.61 t C/ha/yr being retained in the grassland ecosystem. Thus the present Imperata grassland exhibited a high capacity to remove atmospheric CO2 and to induce high C stocks in the soil provided it is protected from burning and overgrazing.Keywords: Above-ground biomass, below-ground biomass, carbon stocks, carbon storage, net primary productivity, soil CO2 flux.DOI: 10.17138/TGFT(419-28  

Foliar uptake of fog water and transport belowground alleviates drought effects in the cloud forest tree species, Drimys brasiliensis (Winteraceae).

Science.gov (United States)

Eller, Cleiton B; Lima, Aline L; Oliveira, Rafael S

2013-07-01

Foliar water uptake (FWU) is a common water acquisition mechanism for plants inhabiting temperate fog-affected ecosystems, but the prevalence and consequences of this process for the water and carbon balance of tropical cloud forest species are unknown. We performed a series of experiments under field and glasshouse conditions using a combination of methods (sap flow, fluorescent apoplastic tracers and stable isotopes) to trace fog water movement from foliage to belowground components of Drimys brasiliensis. In addition, we measured leaf water potential, leaf gas exchange, leaf water repellency and growth of plants under contrasting soil water availabilities and fog exposure in glasshouse experiments to evaluate FWU effects on the water and carbon balance of D. brasiliensis saplings. Fog water diffused directly through leaf cuticles and contributed up to 42% of total foliar water content. FWU caused reversals in sap flow in stems and roots of up to 26% of daily maximum transpiration. Fog water transported through the xylem reached belowground pools and enhanced leaf water potential, photosynthesis, stomatal conductance and growth relative to plants sheltered from fog. Foliar uptake of fog water is an important water acquisition mechanism that can mitigate the deleterious effects of soil water deficits for D. brasiliensis. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Nonlinear Variations of Net Primary Productivity and Its Relationship with Climate and Vegetation Phenology, China

Directory of Open Access Journals (Sweden)

Jian Yang

2017-09-01

Full Text Available Net primary productivity (NPP is an important component of the terrestrial carbon cycle. In this study, NPP was estimated based on two models and Moderate Resolution Imaging Spaectroradiometer (MODIS data. The spatiotemporal patterns of NPP and the correlations with climate factors and vegetation phenology were then analyzed. Our results showed that NPP derived from MODIS performed well in China. Spatially, NPP decreased from the southeast toward the northwest. Temporally, NPP showed a nonlinear increasing trend at a national scale, but the magnitude became slow after 2004. At a regional scale, NPP in Northern China and the Tibetan Plateau showed a nonlinear increasing trend, while the NPP decreased in most areas of Southern China. The decreases in NPP were more than offset by the increases. At the biome level, all vegetation types displayed an increasing trend, except for shrub and evergreen broad forests (EBF. Moreover, a turning point year occurred for all vegetation types, except for EBF. Generally, climatic factors and Length of Season were all positively correlated with the NPP, while the relationships were much more diverse at a regional level. The direct effect of solar radiation on the NPP was larger (0.31 than precipitation (0.25 and temperature (0.07. Our results indicated that China could mitigate climate warming at a regional and/or global scale to some extent during the time period of 2001–2014.

Net-erosion profile model and simulation experiments

International Nuclear Information System (INIS)

Sagara, Akio

2001-01-01

Estimation of net-erosion profile is requisite for evaluating the lifetime of divertor plates under high heat and particle fluxes of fusion plasmas. As a reference in benchmark tests of numerical calculation codes, a self-consistent analytical solution is presented for a simplified divertor condition, wherein the magnetic field line is normal to the target plate and the ionization mean free path of sputtered particles is assumed constant. The primary flux profile of hydrogen and impurities are externally given as well as the return ratio of sputtered atoms to the target. In the direction along the divertor trace, all conditions are uniform. The analytical solution is compared with net-erosion experiments carried out using the Compact Helical System (CHS). The deposition profiles of Ti and O impurities are in very good agreement with the analytical predictions. Recent preliminary results observed on divertor plates in the Large Helical Device (LHD) are briefly presented. (author)

Pro-Nets versus No-Nets: Differences in Urban Older Adults' Predilections for Internet Use

Science.gov (United States)

Cresci, M. Kay; Yarandi, Hossein N.; Morrell, Roger W.

2010-01-01

Enthusiasm for information technology (IT) is growing among older adults. Many older adults enjoy IT and the Internet (Pro-Nets), but others have no desire to use it (No-Nets). This study found that Pro-Nets and No-Nets were different on a number of variables that might predict IT use. No-Nets were older, had less education and income, were…

Net nitrogen mineralization in natural ecosystems across the conterminous US

Science.gov (United States)

LeeAnna Y. Chapman; Steven G. McNulty; Ge Sun; Yang Zhang

2013-01-01

Nitrogen is the primary nutrient limiting ecosystem productivity over most of the US. Although soil nitrogen content is important, knowledge about its spatial extent at the continental scale is limited. The objective of this study was to estimate net nitrogen mineralization for the conterminous US (CONUS) using an empirical modeling approach by scaling up site level...

Development and Validation of a Short-Form Safety Net Medical Home Scale.

Science.gov (United States)

Nocon, Robert S; Gunter, Kathryn E; Gao, Yue; Lee, Sang Mee; Chin, Marshall H

2017-12-01

To develop a short-form Safety Net Medical Home Scale (SNMHS) for assessing patient-centered medical home (PCMH) capability in safety net clinics. National surveys of federally qualified health centers (FQHCs). Interviews with FQHC directors. We constructed three short-form SNMHS versions and examined correlations with full SNMHS and related primary care assessments. We tested usability with FQHC directors and reviewed scale development with an advisory group. Federally qualified health center surveys were administered in 2009 and 2013, by mail and online. Usability testing was conducted through telephone interviews with FQHC directors in 2013. Six-, 12-, and 18-question short-form SNMHS versions had Pearson correlations with full scale of 0.84, 0.92, and 0.96, respectively. All versions showed a level of convergent validity with other primary care assessment scales comparable to the full SNMHS. User testers found short forms to be low-burden, though missing some PCMH concepts. Advisory group members expressed caution over missing concepts and appropriate use of short-form self-assessments. Short-form versions of SNMHS showed strong correlations with full scale and may be useful for brief assessment of safety net PCMH capability. Each short-form SNMHS version may be appropriate for different research, quality improvement, and assessment purposes. © Health Research and Educational Trust.

Experiments and simulation of a net closing mechanism for tether-net capture of space debris

Science.gov (United States)

Sharf, Inna; Thomsen, Benjamin; Botta, Eleonora M.; Misra, Arun K.

2017-10-01

This research addresses the design and testing of a debris containment system for use in a tether-net approach to space debris removal. The tether-net active debris removal involves the ejection of a net from a spacecraft by applying impulses to masses on the net, subsequent expansion of the net, the envelopment and capture of the debris target, and the de-orbiting of the debris via a tether to the chaser spacecraft. To ensure a debris removal mission's success, it is important that the debris be successfully captured and then, secured within the net. To this end, we present a concept for a net closing mechanism, which we believe will permit consistently successful debris capture via a simple and unobtrusive design. This net closing system functions by extending the main tether connecting the chaser spacecraft and the net vertex to the perimeter and around the perimeter of the net, allowing the tether to actuate closure of the net in a manner similar to a cinch cord. A particular embodiment of the design in a laboratory test-bed is described: the test-bed itself is comprised of a scaled-down tether-net, a supporting frame and a mock-up debris. Experiments conducted with the facility demonstrate the practicality of the net closing system. A model of the net closure concept has been integrated into the previously developed dynamics simulator of the chaser/tether-net/debris system. Simulations under tether tensioning conditions demonstrate the effectiveness of the closure concept for debris containment, in the gravity-free environment of space, for a realistic debris target. The on-ground experimental test-bed is also used to showcase its utility for validating the dynamics simulation of the net deployment, and a full-scale automated setup would make possible a range of validation studies of other aspects of a tether-net debris capture mission.

Net carbon exchange across the Arctic tundra-boreal forest transition in Alaska 1981-2000

Science.gov (United States)

Thompson, Catharine Copass; McGuire, A.D.; Clein, Joy S.; Chapin, F. S.; Beringer, J.

2006-01-01

Shifts in the carbon balance of high-latitude ecosystems could result from differential responses of vegetation and soil processes to changing moisture and temperature regimes and to a lengthening of the growing season. Although shrub expansion and northward movement of treeline should increase carbon inputs, the effects of these vegetation changes on net carbon exchange have not been evaluated. We selected low shrub, tall shrub, and forest tundra sites near treeline in northwestern Alaska, representing the major structural transitions expected in response to warming. In these sites, we measured aboveground net primary production (ANPP) and vegetation and soil carbon and nitrogen pools, and used these data to parameterize the Terrestrial Ecosystem Model. We simulated the response of carbon balance components to air temperature and precipitation trends during 1981-2000. In areas experiencing warmer and dryer conditions, Net Primary Production (NPP) decreased and heterotrophic respiration (R H ) increased, leading to a decrease in Net Ecosystem Production (NEP). In warmer and wetter conditions NPP increased, but the response was exceeded by an increase in R H ; therefore, NEP also decreased. Lastly, in colder and wetter regions, the increase in NPP exceeded a small decline in R H , leading to an increase in NEP. The net effect for the region was a slight gain in ecosystem carbon storage over the 20 year period. This research highlights the potential importance of spatial variability in ecosystem responses to climate change in assessing the response of carbon storage in northern Alaska over the last two decades. ?? Springer 2005.

A below-ground herbivore shapes root defensive chemistry in natural plant populations.

Science.gov (United States)

Huber, Meret; Bont, Zoe; Fricke, Julia; Brillatz, Théo; Aziz, Zohra; Gershenzon, Jonathan; Erb, Matthias

2016-03-30

Plants display extensive intraspecific variation in secondary metabolites. However, the selective forces shaping this diversity remain often unknown, especially below ground. Using Taraxacum officinale and its major native insect root herbivore Melolontha melolontha, we tested whether below-ground herbivores drive intraspecific variation in root secondary metabolites. We found that high M. melolontha infestation levels over recent decades are associated with high concentrations of major root latex secondary metabolites across 21 central European T. officinale field populations. By cultivating offspring of these populations, we show that both heritable variation and phenotypic plasticity contribute to the observed differences. Furthermore, we demonstrate that the production of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) is costly in the absence, but beneficial in the presence of M. melolontha, resulting in divergent selection of TA-G. Our results highlight the role of soil-dwelling insects for the evolution of plant defences in nature. © 2016 The Author(s).

Study on Net Primary Productivity over Complicated Mountainous Area based on Multi-Source Remote Sensing Data

Science.gov (United States)

Guan, X.; Shen, H.; Li, X.; Gan, W.

2017-12-01

Mountainous area hosts approximately a quarter of the global land surface, with complex climate and ecosystem conditions. More knowledge about mountainous ecosystem could highly advance our understanding of the global carbon cycle and climate change. Net Primary Productivity (NPP), the biomass increment of plants, is a widely used ecological indicator that can be obtained by remote sensing methods. However, limited by the defective characteristic of sensors, which cannot be long-term with enough spatial details synchronously, the mountainous NPP was far from being understood. In this study, a multi-sensor fusion framework was applied to synthesize a 1-km NPP series from 1982 to 2014 in mountainous southwest China, where elevation ranged from 76m to 6740m. The validation with field-measurements proved this framework greatly improved the accuracy of NPP (r=0.79, prun-off. What is more, it was indicated that the NPP variation showed three distinct stages at the year break-point of 1992 and 2002 over the region. The NPP in low-elevation area varied almost triple more drastic than the high-elevation area for all the three stages, due to the much greater change rate of precipitation. In summary, this study innovatively conducted a long-term and accurate NPP study on the not understood mountainous ecosystem with multi-source data, the framework and conclusions will be beneficial for the further cognition of global climate change.

Variations in Vegetation Net Primary Production in the Qinghai-Xizang Plateau, China, from 1982 to 1999

Energy Technology Data Exchange (ETDEWEB)

Piao, S.; Fang, J.; He, J. [Department of Ecology, College of Environmental Science, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, 100871 (China)

2006-01-15

Vegetation net primary production (NPP) derived from a carbon model (Carnegie-Ames-Stanford Approach, CASA) and its interannual change in the Qinghai-Xizang (Tibetan) Plateau were investigated in this study using 1982-1999 time series data sets of normalized difference vegetation index (NDVI) and paired ground-based information on vegetation, climate, soil, and solar radiation. The 18-year averaged annual NPP over the plateau was 125 g C m-2 yr-1, decreasing from the southeast to the northwest, consistent with precipitation and temperature patterns. Total annual NPP was estimated between 0.183 and 0.244 Pg C over the 18 years, with an average of 0.212 Pg C (1 Pg = 1015 g). Two distinct periods (1982-1990 and 1991-1999) of NPP variation were observed, separated by a sharp reduction during 1990-1991. From 1982 to 1990, annual NPP did not show a significant trend, while from 1991 to 1999 a marked increase of 0.007 Pg C yr-2 was observed. NPP trends for most vegetation types resembled that of the whole plateau. The largest annual NPP increase during 1991-1999 appeared in alpine meadows, accounting for 32.3% of the increment of the whole region. Changes in solar radiation and temperature significantly influenced NPP variation, suggesting that solar radiation may be one of the major factors associated with changes in NPP.

Future supply and demand of net primary production in the Sahel

Science.gov (United States)

Sallaba, Florian; Olin, Stefan; Engström, Kerstin; Abdi, Abdulhakim M.; Boke-Olén, Niklas; Lehsten, Veiko; Ardö, Jonas; Seaquist, Jonathan W.

2017-12-01

In the 21st century, climate change in combination with increasing demand, mainly from population growth, will exert greater pressure on the ecosystems of the Sahel to supply food and feed resources. The balance between supply and demand, defined as the annual biomass required for human consumption, serves as a key metric for quantifying basic resource shortfalls over broad regions.Here we apply an exploratory modelling framework to analyse the variations in the timing and geography of different NPP (net primary production) supply-demand scenarios, with distinct assumptions determining supply and demand, for the 21st century Sahel. We achieve this by coupling a simple NPP supply model forced with projections from four representative concentration pathways with a global, reduced-complexity demand model driven by socio-economic data and assumptions derived from five shared socio-economic pathways.For the scenario that deviates least from current socio-economic and climate trends, we find that per capita NPP begins to outstrip supply in the 2040s, while by 2050 half the countries in the Sahel experience NPP shortfalls. We also find that despite variations in the timing of the onset of NPP shortfalls, demand cannot consistently be met across the majority of scenarios. Moreover, large between-country variations are shown across the scenarios, in which by the year 2050 some countries consistently experience shortage or surplus, while others shift from surplus to shortage. At the local level (i.e. grid cell), hotspots of total NPP shortfall consistently occur in the same locations across all scenarios but vary in size and magnitude. These hotspots are linked to population density and high demand. For all scenarios, total simulated NPP supply doubles by 2050 but is outpaced by increasing demand due to a combination of population growth and the adoption of diets rich in animal products. Finally, variations in the timing of the onset and end of supply shortfalls stem from

Decadal-Scale Reduction in Forest Net Ecosystem Production Following Insect Defoliation Contrasts with Short-Term Impacts of Prescribed Fires

Science.gov (United States)

Kenneth L. Clark; Heidi J. Renninger; Nicholas Skowronski; Michael Gallagher; Karina V.R.  Schäfer

2018-01-01

Understanding processes underlying forest carbon dynamics is essential for accurately predicting the outcomes of non-stand-replacing disturbance in intermediate-age forests. We quantified net ecosystem production (NEP), aboveground net primary production (ANPP), and the dynamics of major carbon (C) pools before and during the decade following invasive insect...

Luxury consumption of soil nutrients: a possible competitive strategy in above-ground and below-ground biomass allocation and root morphology for slow-growing arctic vegetation?

NARCIS (Netherlands)

Wijk, van M.T.; Williams, M.; Gough, L.; Hobbie, S.E.; Shaver, G.R.

2003-01-01

1 A field-experiment was used to determine how plant species might retain dominance in an arctic ecosystem receiving added nutrients. We both measured and modelled the above-ground and below-ground biomass allocation and root morphology of non-acidic tussock tundra near Toolik Lake, Alaska, after 4

ROOT.NET: Using ROOT from .NET languages like C# and F#

Science.gov (United States)

Watts, G.

2012-12-01

ROOT.NET provides an interface between Microsoft's Common Language Runtime (CLR) and .NET technology and the ubiquitous particle physics analysis tool, ROOT. ROOT.NET automatically generates a series of efficient wrappers around the ROOT API. Unlike pyROOT, these wrappers are statically typed and so are highly efficient as compared to the Python wrappers. The connection to .NET means that one gains access to the full series of languages developed for the CLR including functional languages like F# (based on OCaml). Many features that make ROOT objects work well in the .NET world are added (properties, IEnumerable interface, LINQ compatibility, etc.). Dynamic languages based on the CLR can be used as well, of course (Python, for example). Additionally it is now possible to access ROOT objects that are unknown to the translation tool. This poster will describe the techniques used to effect this translation, along with performance comparisons, and examples. All described source code is posted on the open source site CodePlex.

ROOT.NET: Using ROOT from .NET languages like C and F

International Nuclear Information System (INIS)

Watts, G

2012-01-01

ROOT.NET provides an interface between Microsoft's Common Language Runtime (CLR) and .NET technology and the ubiquitous particle physics analysis tool, ROOT. ROOT.NET automatically generates a series of efficient wrappers around the ROOT API. Unlike pyROOT, these wrappers are statically typed and so are highly efficient as compared to the Python wrappers. The connection to .NET means that one gains access to the full series of languages developed for the CLR including functional languages like F (based on OCaml). Many features that make ROOT objects work well in the .NET world are added (properties, IEnumerable interface, LINQ compatibility, etc.). Dynamic languages based on the CLR can be used as well, of course (Python, for example). Additionally it is now possible to access ROOT objects that are unknown to the translation tool. This poster will describe the techniques used to effect this translation, along with performance comparisons, and examples. All described source code is posted on the open source site CodePlex.

Calibration of a biome-biogeochemical cycles model for modeling the net primary production of teak forests through inverse modeling of remotely sensed data

Science.gov (United States)

Imvitthaya, Chomchid; Honda, Kiyoshi; Lertlum, Surat; Tangtham, Nipon

2011-01-01

In this paper, we present the results of a net primary production (NPP) modeling of teak (Tectona grandis Lin F.), an important species in tropical deciduous forests. The biome-biogeochemical cycles or Biome-BGC model was calibrated to estimate net NPP through the inverse modeling approach. A genetic algorithm (GA) was linked with Biome-BGC to determine the optimal ecophysiological model parameters. The Biome-BGC was calibrated by adjusting the ecophysiological model parameters to fit the simulated LAI to the satellite LAI (SPOT-Vegetation), and the best fitness confirmed the high accuracy of generated ecophysioligical parameter from GA. The modeled NPP, using optimized parameters from GA as input data, was evaluated using daily NPP derived by the MODIS satellite and the annual field data in northern Thailand. The results showed that NPP obtained using the optimized ecophysiological parameters were more accurate than those obtained using default literature parameterization. This improvement occurred mainly because the model's optimized parameters reduced the bias by reducing systematic underestimation in the model. These Biome-BGC results can be effectively applied in teak forests in tropical areas. The study proposes a more effective method of using GA to determine ecophysiological parameters at the site level and represents a first step toward the analysis of the carbon budget of teak plantations at the regional scale.

Initial Results From The Micro-pulse Lidar Network (MPL-Net)

Science.gov (United States)

Welton, E. J.; Campbell, J. R.; Berkoff, T. A.; Spinhirne, J. D.; Ginoux, P.

2001-12-01

The micro-pulse lidar system (MPL) was developed in the early 1990s and was the first small, eye-safe, and autonomous lidar built for fulltime monitoring of cloud and aerosol vertical distributions. In 2000, a new project using MPL systems was started at NASA Goddard Space Flight Center. This new project, the Micro-pulse Lidar Network or MPL-Net, was created to provide long-term observations of aerosol and cloud vertical profiles at key sites around the world. This is accomplished using both NASA operated sites and partnerships with other organizations owning MPL systems. The MPL-Net sites are co-located with NASA AERONET sunphotometers to provide aerosol optical depth data needed for calibration of the MPL. In addition to the long-term sites, MPL-Net provides lidar support for a limited number of field experiments and ocean cruises each year. We will present an overview of the MPL-Net project and show initial results from the first two MPL-Net sites at the South Pole and at Goddard Space Flight Center. Observations of dust layers transported from the desert regions of China, across the Pacific Ocean, to the east coast of the United States will also be shown. MPL-Net affiliated instruments were in place at the desert source region in China, on a research vessel in the Sea of Japan, at ARM sites in Alaska and Oklahoma, and finally at our home site in Maryland (GSFC) during the massive dust storms that occurred in April 2001. The MPL observations of dust layers at each location are shown in comparison to dust layers predicted using the Georgia Tech/Goddard Global Ozone Chemistry Aerosol Radiation and Transport model (GOCART). Finally, the MPL-Net project is the primary ground-validation program for the Geo-Science Laser Altimeter System (GLAS) satellite lidar project (launch date 2002). We will present an overview demonstrating how MPL-Net results are used to help prepare the GLAS data processing algorithms and assist in the calibration/validation of the GLAS data

Initial Results from the Micro-pulse Lidar Network (MPL-Net)

Science.gov (United States)

Welton, Ellsworth J.; Campbell, James R.; Berkoff, Timothy A.; Spinhirne, James D.; Ginoux, Paul; Starr, David OC. (Technical Monitor)

2001-01-01

The micro-pulse lidar system (MPL) was developed in the early 1990s and was the first small, eye-safe, and autonomous lidar built for full time monitoring of cloud and aerosol vertical distributions. In 2000, a new project using MPL systems was started at NASA Goddard Space Flight Center. This new project, the Micro-pulse Lidar Network or MPL-Net, was created to provide long-term observations of aerosol and cloud vertical profiles at key sites around the world. This is accomplished using both NASA operated sites and partnerships with other organizations owning MPL systems. The MPL-Net sites are co-located with NASA AERONET sunphotometers to provide aerosol optical depth data needed for calibration of the MPL. In addition to the long-term sites, MPL-Net provides lidar support for a limited number of field experiments and ocean cruises each year. We will present an overview of the MPL-Net project and show initial results from the first two MPL-Net sites at the South Pole and at Goddard Space Flight Center. Observations of dust layers transported from the Gobi desert, across the Pacific Ocean, to the east coast of the United States will also be shown. MPL-Net affiliated instruments were in place at the desert source region in China, on a research vessel in the Sea of Japan, at ARM sites in Alaska and Oklahoma, and finally at our home site in Maryland (GSFC) during the massive dust storms that occurred in April 2001. The MPL observations of dust layers at each location are shown in comparison to dust layers predicted using the Georgia Tech/Goddard Global Ozone Chemistry Aerosol Radiation and Transport model (GOCART). Finally, the MPL-Net project is the primary ground-validation program for the Geo-Science Laser Altimeter System (GLAS) satellite lidar project (launch date 2002). We will present an overview demonstrating how MPL-Net results are used to help prepare the GLAS data processing algorithms and assist in the calibration/validation of the GLAS data products.

Treatment of neuroendocrine tumors (NETs) expressing SMT 90Y and 177Lu

International Nuclear Information System (INIS)

Oliva González, Juan P.; Baum, Richard

2016-01-01

Neuroendocrine tumors (NETs) are a relatively rare and extremely heterogeneous group, essentially characterized by a different metabolism and endocrine histologically pattern. NETs are a challenge for physicians not only for diagnosis but also for early treatment. In addition to this, QT or RT treatments that require a high rate of cell proliferation to be effective, they are not in these tumors as slow growth. The primary treatment of NETs is surgery, either with a curative intent or tumor shrinkage. Peptide Receptors Radiotherapy (RTPR) consists of the administration for therapeutic purposes of Radiolabeled Synthetic Peptides that bind specifically and with high affinity to receptors of tumor cells. The RTPR of TNE with SMT analogues is effective for handling or metastizados inoperable patients. The Conference gives an accurate picture of the treatment of these tumors both 90 Y as 177 Lu. (author)

Aboveground Net Primary Production of tree cover at the post-disturbance area in the Tatra National Park, Slovakia

Directory of Open Access Journals (Sweden)

Konôpka Bohdan

2015-09-01

Full Text Available Large-scale disturbances under the conditions of Slovakia, caused especially by storm and bark beetle, bring dramatic decline in carbon budget of the country, besides other negative consequences. The largest disturbance in modern history of the Slovak forestry was the storm damage that occurred in November 2004. The Tatra National Park (TNP was one of the most affected regions. Thus, in this territory, two transects (T1 – the Danielov dom site and T2 – near the Horný Smokovec village were established to survey basic dendrometric properties of trees in young stands established after the disaster. The standing stock of aboveground biomass in tree cover for the spring and autumn 2014 was calculated using the recorded variables, i.e. tree height and diameter measured at the stem base, together with the region-specific allometric relations. Then, the Aboveground Net Primary Production (ANPP in tree cover was estimated with respect to its components (stem, branches and foliage. ANPP was 315 g m−2 per year (Transect T1, and 391 g m−2 per year (Transect T2. The differences in the structure of ANPP, i.e. contribution of tree components, were found between transects T1 and T2. They were caused by the contrasting tree species composition, specifically the ratios between Norway spruce and broadleaved species. Broadleaves allocated more biomass production to foliage than spruce. This phenomenon together with higher turnover (once a year of foliage caused that broadleaves manifest higher share of fast-cycling carbon in comparison to the amount of carbon sequestrated in woody parts (stem and branches. High variability of ANPP was found within the transects, i.e. among the plots (microsites. As for the representative estimation of the standing stock of aboveground part of tree cover as well as ANPP at the post-disturbance area in the TNP territory, the survey should be performed on a net of research plots. Only this approach enables reliable estimates

Carbon allocation belowground in Pinus pinaster using stable carbon isotope pulse labeling technique

Science.gov (United States)

Dannoura, M.; Bosc, A.; Chipeaux, C.; Sartore, M.; Lambrot, C.; Trichet, P.; Bakker, M.; Loustau, D.; Epron, D.

2010-12-01

Carbon allocation belowground competes with aboveground growth and biomass production. In the other hand, it contributes to resource acquisition such as nutrient, water and carbon sequestration in soil. Thus, a better characterization of carbon flow from plant to soil and its residence time within each compartment is an important issue for understanding and modeling forest ecosystem carbon budget. 13C pulse labeling of whole crown was conducted at 4 seasons to study the fate of assimilated carbon by photosynthesis into the root on 12 year old Pinus pinaster planted in the INRA domain of Pierroton. Maritime pine is the most widely planted species in South-West Europe. Stem, root and soil CO2 effluxes and their isotope composition were measured continuously by tunable diode laser absorption spectroscopy with a trace gas analyzer (TGA 100A; Campbell Scientific) coupled to flow-through chambers. 13CO2 recovery and peak were observed in respiration of each compartment after labeling. It appeared sequentially from top of stem to bottom, and to coarse root. The maximum velocity of carbon transfer was calculated as the difference in time lag of recovery between two positions on the trunk or on the root. It ranged between 0.08-0.2 m h-1 in stem and between 0.04-0.12 m h-1 in coarse root. This velocity was higher in warmer season, and the difference between time lag of recovery and peak increased after first frost. Photosynthates arrived underground 1.5 to 5 days after labeling, at similar time in soil CO2 effluxes and coarse root respiration. 0.08-1.4 g of carbon was respired per tree during first 20 days following labeling. It presented 0.6 -10% of 13C used for labeling and it is strongly related to seasons. The isotope signal was detected in fine root organs and microbial biomass by periodical core sampling. The peak was observed 6 days after labeling in early summer while it was delayed more than 10 days in autumn and winter with less amount of carbon allocated

FiberNet--a new embolic protection device for carotid artery stenting.

Science.gov (United States)

Bauer, C; Franke, J; Bertog, S C; Woerner, V; Ghasemzadeh-Asl, S; Sievert, H

2014-05-01

Though distal filter protection during carotid stenting reduces the risk of cerebrovascular events, periprocedural stroke remains a risk despite their broad usage. This observation may be related to the pore size of common filters. The FiberNet distal filter system is unique by its very small pore size (40 µm) as well as its low profile and flexibility. Little data is available regarding the clinical performance and safety of this device. The aim was the evaluation of the safety of the FiberNet embolic protection system during carotid artery stenting. All consecutive patients treated with carotid stenting at our institution using the FiberNet device were systematically followed. Primary endpoint was the rate of all death and stroke within 30 days of the procedure. Carotid artery stenting using the FiberNet embolic protection system was performed in 54 patients. The procedure was technical successful in all patients. Three patients (5.5%) had a TIA. Amauosis fugax occurred in two patients (3.7%). One patient (1.9%) had a minor stroke with hemiparesis of the left arm and face which resolved completely within 48 hr after the procedure. No patient died or suffered a major stroke. The safety and feasibility of the FiberNet distal protection system appears to be at least equivalent to that reported in studies using conventional distal filter protection. Copyright © 2013 Wiley Periodicals, Inc.

INMARSAT-C SafetyNET

Science.gov (United States)

Tsunamis 406 EPIRB's National Weather Service Marine Forecasts INMARSAT-C SafetyNET Marine Forecast Offices greater danger near shore or any shallow waters? NATIONAL WEATHER SERVICE PRODUCTS VIA INMARSAT-C SafetyNET Inmarsat-C SafetyNET is an internationally adopted, automated satellite system for promulgating

Primary controls on species richness in higher taxa.

Science.gov (United States)

Rabosky, Daniel L

2010-12-01

The disparity in species richness across the tree of life is one of the most striking and pervasive features of biological diversity. Some groups are exceptionally diverse, whereas many other groups are species poor. Differences in diversity among groups are frequently assumed to result from primary control by differential rates of net diversification. However, a major alternative explanation is that ecological and other factors exert primary control on clade diversity, such that apparent variation in net diversification rates is a secondary consequence of ecological limits on clade growth. Here, I consider a likelihood framework for distinguishing between these competing hypotheses. I incorporate hierarchical modeling to explicitly relax assumptions about the constancy of diversification rates across clades, and I propose several statistics for a posteriori evaluation of model adequacy. I apply the framework to a recent dated phylogeny of ants. My results reject the hypothesis that net diversification rates exert primary control on species richness in this group and demonstrate that clade diversity is better explained by total time-integrated speciation. These results further suggest that it may not possible to estimate meaningful speciation and extinction rates from higher-level phylogenies of extant taxa only.

Quantum net dynamics

International Nuclear Information System (INIS)

Finkelstein, D.

1989-01-01

The quantum net unifies the basic principles of quantum theory and relativity in a quantum spacetime having no ultraviolet infinities, supporting the Dirac equation, and having the usual vacuum as a quantum condensation. A correspondence principle connects nets to Schwinger sources and further unifies the vertical structure of the theory, so that the functions of the many hierarchic levels of quantum field theory (predicate algebra, set theory, topology,hor-ellipsis, quantum dynamics) are served by one in quantum net dynamics

High-level Petri Nets

DEFF Research Database (Denmark)

various journals and collections. As a result, much of this knowledge is not readily available to people who may be interested in using high-level nets. Within the Petri net community this problem has been discussed many times, and as an outcome this book has been compiled. The book contains reprints...... of some of the most important papers on the application and theory of high-level Petri nets. In this way it makes the relevant literature more available. It is our hope that the book will be a useful source of information and that, e.g., it can be used in the organization of Petri net courses. To make......High-level Petri nets are now widely used in both theoretical analysis and practical modelling of concurrent systems. The main reason for the success of this class of net models is that they make it possible to obtain much more succinct and manageable descriptions than can be obtained by means...

Children's schemes for anticipating the validity of nets for solids

Science.gov (United States)

Wright, Vince; Smith, Ken

2017-09-01

There is growing acknowledgement of the importance of spatial abilities to student achievement across a broad range of domains and disciplines. Nets are one way to connect three-dimensional shapes and their two-dimensional representations and are a common focus of geometry curricula. Thirty-four students at year 6 (upper primary school) were interviewed on two occasions about their anticipation of whether or not given nets for the cube- and square-based pyramid would fold to form the target solid. Vergnaud's ( Journal of Mathematical Behavior, 17(2), 167-181, 1998, Human Development, 52, 83-94, 2009) four characteristics of schemes were used as a theoretical lens to analyse the data. Successful schemes depended on the interaction of operational invariants, such as strategic choice of the base, rules for action, particularly rotation of shapes, and anticipations of composites of polygons in the net forming arrangements of faces in the solid. Inferences were rare. These data suggest that students need teacher support to make inferences, in order to create transferable schemes.

StreamNet Project : Annual Report Fiscal Year 2008.

Energy Technology Data Exchange (ETDEWEB)

Schmidt, Bruce; Roger, Phil; Oftedahl, Lenora

2008-12-12

Fiscal Year 2008 (FY-08) represents a transitional year for the StreamNet project. While the project continued to acquire/update, standardize, georeference and disseminate fish-related data for the state, some tribal and one federal fisheries agencies, it also took on several new initiatives and is anticipating new regional guidance on data needs. Passage of the Columbia Basin Accords caused an administrative change within the project, separating the work done by the Columbia River Inter-Tribal Fish Commission (CRITFC) out to a separate contract with BPA. This will change the structure of the StreamNet contract but not change the relationship with the StreamNet Library or data developed by CRITFC, and will likely increase the availability of tribal data to StreamNet due to increased funding for tribal data efforts. This change will take effect in FY-09. We also expect that data work will be adjusted in the future in response to executive level policy direction in the Columbia Basin based on efforts to establish priorities under a regional data management framework. Data development emphasis was shifted this year to place highest priority on data that support indicators of fish abundance for the focal species covered in the Status of the Resource (SOTR) report, as requested by the Columbia Basin Fish and Wildlife Authority (CBFWA) Data Management Framework Subcommittee. We instituted an XML based web service allowing direct access to data from the project database for CBFWA to update the SOTR report. The project also increased efforts to work with tribal fisheries managers to provide data related assistance and to include tribal data in the StreamNet database. A primary theme this year was exploring means to speed the flow of data. We had ongoing success in our strategic emphasis on increasing automation of data conversion through development of comprehensive database systems within our partner agencies, as outlined in our Vision and Strategic Plan. By assisting

The incidence of Clostridioides difficile and Clostridium perfringens netF-positive strains in diarrheic dogs.

Science.gov (United States)

Diniz, Amanda Nadia; Coura, Fernanda Morcatti; Rupnik, Maja; Adams, Vicki; Stent, Thomas L; Rood, Julian I; de Oliveira, Carlos Augusto; Lobato, Francisco Carlos Faria; Silva, Rodrigo Otávio Silveira

2018-02-01

The aim of this study was to examine the incidence of Clostridioides (previously Clostridium) difficile and Clostridium perfringens in the feces of diarrheic and non-diarrheic dogs. Also, the presence of other common canine enteropathogens was examined. Toxigenic C. difficile and C. perfringens positive for the NetF-encoding gene (netF) were detected in 11 (11.9%) and seven (7.6%) diarrheic dogs, respectively. Three dogs were diagnosed simultaneously with toxigenic C. difficile and netF-positive C. perfringens. Among other enteropathogens, Giardia sp. was the most common agent detected in dogs positive for toxigenic C. difficile or netF-positive C. perfringens. The results suggest that C. difficile and C. perfringens occur more frequently as a primary cause of diarrhea. Copyright © 2017 Elsevier Ltd. All rights reserved.

Creating a Regional MODIS Satellite-Driven Net Primary Production Dataset for European Forests

Directory of Open Access Journals (Sweden)

Mathias Neumann

2016-06-01

Full Text Available Net primary production (NPP is an important ecological metric for studying forest ecosystems and their carbon sequestration, for assessing the potential supply of food or timber and quantifying the impacts of climate change on ecosystems. The global MODIS NPP dataset using the MOD17 algorithm provides valuable information for monitoring NPP at 1-km resolution. Since coarse-resolution global climate data are used, the global dataset may contain uncertainties for Europe. We used a 1-km daily gridded European climate data set with the MOD17 algorithm to create the regional NPP dataset MODIS EURO. For evaluation of this new dataset, we compare MODIS EURO with terrestrial driven NPP from analyzing and harmonizing forest inventory data (NFI from 196,434 plots in 12 European countries as well as the global MODIS NPP dataset for the years 2000 to 2012. Comparing these three NPP datasets, we found that the global MODIS NPP dataset differs from NFI NPP by 26%, while MODIS EURO only differs by 7%. MODIS EURO also agrees with NFI NPP across scales (from continental, regional to country and gradients (elevation, location, tree age, dominant species, etc.. The agreement is particularly good for elevation, dominant species or tree height. This suggests that using improved climate data allows the MOD17 algorithm to provide realistic NPP estimates for Europe. Local discrepancies between MODIS EURO and NFI NPP can be related to differences in stand density due to forest management and the national carbon estimation methods. With this study, we provide a consistent, temporally continuous and spatially explicit productivity dataset for the years 2000 to 2012 on a 1-km resolution, which can be used to assess climate change impacts on ecosystems or the potential biomass supply of the European forests for an increasing bio-based economy. MODIS EURO data are made freely available at ftp://palantir.boku.ac.at/Public/MODIS_EURO.

Logging disturbance shifts net primary productivity and its allocation in Bornean tropical forests.

Science.gov (United States)

Riutta, Terhi; Malhi, Yadvinder; Kho, Lip Khoon; Marthews, Toby R; Huaraca Huasco, Walter; Khoo, MinSheng; Tan, Sylvester; Turner, Edgar; Reynolds, Glen; Both, Sabine; Burslem, David F R P; Teh, Yit Arn; Vairappan, Charles S; Majalap, Noreen; Ewers, Robert M

2018-01-24

Tropical forests play a major role in the carbon cycle of the terrestrial biosphere. Recent field studies have provided detailed descriptions of the carbon cycle of mature tropical forests, but logged or secondary forests have received much less attention. Here, we report the first measures of total net primary productivity (NPP) and its allocation along a disturbance gradient from old-growth forests to moderately and heavily logged forests in Malaysian Borneo. We measured the main NPP components (woody, fine root and canopy NPP) in old-growth (n = 6) and logged (n = 5) 1 ha forest plots. Overall, the total NPP did not differ between old-growth and logged forest (13.5 ± 0.5 and 15.7 ± 1.5 Mg C ha -1  year -1 respectively). However, logged forests allocated significantly higher fraction into woody NPP at the expense of the canopy NPP (42% and 48% into woody and canopy NPP, respectively, in old-growth forest vs 66% and 23% in logged forest). When controlling for local stand structure, NPP in logged forest stands was 41% higher, and woody NPP was 150% higher than in old-growth stands with similar basal area, but this was offset by structure effects (higher gap frequency and absence of large trees in logged forest). This pattern was not driven by species turnover: the average woody NPP of all species groups within logged forest (pioneers, nonpioneers, species unique to logged plots and species shared with old-growth plots) was similar. Hence, below a threshold of very heavy disturbance, logged forests can exhibit higher NPP and higher allocation to wood; such shifts in carbon cycling persist for decades after the logging event. Given that the majority of tropical forest biome has experienced some degree of logging, our results demonstrate that logging can cause substantial shifts in carbon production and allocation in tropical forests. © 2018 John Wiley & Sons Ltd.

Planning of nets

International Nuclear Information System (INIS)

Carberry, M

1996-01-01

The paper is about the planning of nets in areas of low density like it is the case of the rural areas. The author includes economic and technological aspects, planning of nets, demands and management among others

Belowground Plant–Herbivore Interactions Vary among Climate-Driven Range-Expanding Plant Species with Different Degrees of Novel Chemistry

Directory of Open Access Journals (Sweden)

Rutger A. Wilschut

2017-10-01

Full Text Available An increasing number of studies report plant range expansions to higher latitudes and altitudes in response to global warming. However, consequences for interactions with other species in the novel ranges are poorly understood. Here, we examine how range-expanding plant species interact with root-feeding nematodes from the new range. Root-feeding nematodes are ubiquitous belowground herbivores that may impact the structure and composition of natural vegetation. Because of their ecological novelty, we hypothesized that range-expanding plant species will be less suitable hosts for root-feeding nematodes than native congeneric plant species. In greenhouse and lab trials we compared nematode preference and performance of two root-feeding nematode species between range-expanding plant species and their congeneric natives. In order to understand differences in nematode preferences, we compared root volatile profiles of all range-expanders and congeneric natives. Nematode preferences and performances differed substantially among the pairs of range-expanders and natives. The range-expander that had the most unique volatile profile compared to its related native was unattractive and a poor host for nematodes. Other range-expanding plant species that differed less in root chemistry from native congeners, also differed less in nematode attraction and performance. We conclude that the three climate-driven range-expanding plant species studied varied considerably in their chemical novelty compared to their congeneric natives, and therefore affected native root-feeding nematodes in species-specific ways. Our data suggest that through variation in chemical novelty, range-expanding plant species may vary in their impacts on belowground herbivores in the new range.

Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

Energy Technology Data Exchange (ETDEWEB)

Sathre, Roger [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Gustavsson, Leif [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Bergh, Johan [Ecotechnology, Mid Sweden University, Ostersund (Sweden); Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp (Sweden)

2010-04-15

In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO{sub 2equiv} if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

International Nuclear Information System (INIS)

Sathre, Roger; Gustavsson, Leif; Bergh, Johan

2010-01-01

In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO 2equiv if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission.

Primary energy and greenhouse gas implications of increasing biomass production through forest fertilization

Energy Technology Data Exchange (ETDEWEB)

Sathre, Roger; Gustavsson, Leif [Ecotechnology, Mid Sweden University, Oestersund (Sweden); Bergh, Johan [Ecotechnology, Mid Sweden University, Oestersund (Sweden); Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp (Sweden)

2010-04-15

In this study we analyze the primary energy and greenhouse gas (GHG) implications of increasing biomass production by fertilizing 10% of Swedish forest land. We estimate the primary energy use and GHG emissions from forest management including production and application of N and NPK fertilizers. Based on modelled growth response, we then estimate the net primary energy and GHG benefits of using biomaterials and biofuels obtained from the increased forest biomass production. The results show an increased annual biomass harvest of 7.4 million t dry matter, of which 41% is large-diameter stemwood. About 6.9 PJ/year of additional primary energy input is needed for fertilizer production and forest management. Using the additional biomass for fuel and material substitution can reduce fossil primary energy use by 150 or 164 PJ/year if the reference fossil fuel is fossil gas or coal, respectively. About 22% of the reduced fossil energy use is due to material substitution and the remainder is due to fuel substitution. The net annual primary energy benefit corresponds to about 7% of Sweden's total primary energy use. The resulting annual net GHG emission reduction is 11.9 million or 18.1 million tCO{sub 2equiv} if the reference fossil fuel is fossil gas or coal, respectively, corresponding to 18% or 28% of the total Swedish GHG emissions in 2007. A significant one-time carbon stock increase also occurs in wood products and forest tree biomass. These results suggest that forest fertilization is an attractive option for increasing energy security and reducing net GHG emission. (author)

A Value Chain Analysis of ghost nets in the Arafura Sea: identifying trans-boundary stakeholders, intervention points and livelihood trade-offs.

Science.gov (United States)

Butler, J R A; Gunn, R; Berry, H L; Wagey, G A; Hardesty, B D; Wilcox, C

2013-07-15

Lost or discarded fishing nets are a significant component of marine debris which has trans-boundary impacts in large marine ecosystems. Such 'ghost nets' cause the by-catch of marine fauna and require retrieval from coastlines where they wash up. Identifying the causes of discarded nets and feasible intervention points requires analysis of a complex value chain and the stakeholders within it, yet no studies have attempted this. In this paper we combine Value Chain Analysis, commonly applied to understand value-adding for a commodity, with elements of Life Cycle Assessment and social network analysis to examine the drivers, stakeholders, economic, environmental and social costs and benefits in the life of a trawl net. We use the Arafura Sea as a case study, which is shared by Indonesia, Papua New Guinea and Australia, and is the focus of a Trans-boundary Diagnostic Assessment (TDA) within the Arafura-Timor Seas Ecosystem Action program (ATSEA). We follow a trawl net through four sub-systems: manufacture of webbing in South Korea, fishing and loss by an Indonesian vessel, retrieval as ghost net on the northern Australian coastline by Indigenous rangers, and disposal or re-cycling as 'GhostNet Art' by Indigenous artists. Primary stakeholders along the value chain incur economic and social benefits, and economic and environmental costs. There is an anomaly in the chain between Indonesian fishermen and Indigenous rangers, artists and communities due to the lack of market linkages between these primary stakeholders. The first 'nexus of influence' where reductions in net losses and environmental costs can be achieved is through interactions between GhostNets Australia, the World Wide Fund for Nature and the Australian Government, which can influence Indonesian fishery management institutions and fishing crews. The second nexus is via the international art market which by publicising GhostNet Art can raise awareness amongst fish consumers about the impacts of ghost nets

Programming NET Web Services

CERN Document Server

Ferrara, Alex

2007-01-01

Web services are poised to become a key technology for a wide range of Internet-enabled applications, spanning everything from straight B2B systems to mobile devices and proprietary in-house software. While there are several tools and platforms that can be used for building web services, developers are finding a powerful tool in Microsoft's .NET Framework and Visual Studio .NET. Designed from scratch to support the development of web services, the .NET Framework simplifies the process--programmers find that tasks that took an hour using the SOAP Toolkit take just minutes. Programming .NET

Global Distribution of Net Electron Acceptance in Subseafloor Sediment

Science.gov (United States)

Fulfer, V. M.; Pockalny, R. A.; D'Hondt, S.

2017-12-01

We quantified the global distribution of net electron acceptance rates (e-/m2/year) in subseafloor sediment (>1.5 meters below seafloor [mbsf]) using (i) a modified version of the chemical-reaction-rate algorithm by Wang et al. (2008), (ii) physical properties and dissolved oxygen and sulfate data from interstitial waters of sediment cores collected by the Ocean Drilling Program, Integrated Ocean Drilling Program, International Ocean Discovery Program, and U.S. coring expeditions, and (iii) correlation of net electron acceptance rates to global oceanographic properties. Calculated net rates vary from 4.8 x 1019 e-/m2/year for slowly accumulating abyssal clay to 1.2 x 1023 e-/m2/year for regions of high sedimentation rate. Net electron acceptance rate correlates strongly with mean sedimentation rate. Where sedimentation rate is very low (e.g., 1 m/Myr), dissolved oxygen penetrates more than 70 mbsf and is the primary terminal electron acceptor. Where sedimentation rate is moderate (e.g., 3 to 60 m/Myr), dissolved sulfate penetrates as far as 700 mbsf and is the principal terminal electron acceptor. Where sedimentation rate is high (e.g., > 60 m/Myr), dissolved sulfate penetrates only meters, but is the principal terminal electron acceptor in subseafloor sediment to the depth of sulfate penetration. Because microbial metabolism continues at greater depths than the depth of sulfate penetration in fast-accumulating sediment, complete quantification of subseafloor metabolic rates will require consideration of other chemical species.

Improving timeliness and efficiency in the referral process for safety net providers: application of the Lean Six Sigma methodology.

Science.gov (United States)

Deckard, Gloria J; Borkowski, Nancy; Diaz, Deisell; Sanchez, Carlos; Boisette, Serge A

2010-01-01

Designated primary care clinics largely serve low-income and uninsured patients who present a disproportionate number of chronic illnesses and face great difficulty in obtaining the medical care they need, particularly the access to specialty physicians. With limited capacity for providing specialty care, these primary care clinics generally refer patients to safety net hospitals' specialty ambulatory care clinics. A large public safety net health system successfully improved the effectiveness and efficiency of the specialty clinic referral process through application of Lean Six Sigma, an advanced process-improvement methodology and set of tools driven by statistics and engineering concepts.

Evidence that acidification-induced declines in plant diversity and productivity are mediated by changes in below-ground communities and soil properties in a semi-arid steppe

Science.gov (United States)

Chen, Dima; Lan, Zhichun; Bai, Xue; Grace, James B.; Bai, Yongfei

2013-01-01

Anthropogenic acid deposition–induced soil acidification is one of the major threats to biodiversity, ecosystem functioning and services. Few studies, however, have explored in detail how above-ground changes in plant species richness and productivity resulting from soil acidification are mediated by effects on below-ground biota and soil properties.

Foliage litter quality and annual net N mineralization: comparison across North American forest sites.

Science.gov (United States)

Scott, Neal A; Binkley, Dan

1997-07-01

The feedback between plant litterfall and nutrient cycling processes plays a major role in the regulation of nutrient availability and net primary production in terrestrial ecosystems. While several studies have examined site-specific feedbacks between litter chemistry and nitrogen (N) availability, little is known about the interaction between climate, litter chemistry, and N availability across different ecosystems. We assembled data from several studies spanning a wide range of vegetation, soils, and climatic regimes to examine the relationship between aboveground litter chemistry and annual net N mineralization. Net N mineralization declined strongly and non-linearly as the litter lignin:N ratio increased in forest ecosystems (r 2  = 0.74, P mineralization decreased linearly as litter lignin concentration increased, but the relationship was significant (r 2  = 0.63, P mineralization across this range of sites (r 2  litter lignin:N ratio and net N mineralization from forest floor and mineral soil was similar. The litter lignin:N ratio explained more of the variation in net N mineralization than climatic factors over a wide range of forest age classes, suggesting that litter quality (lignin:N ratio) may exert more than a proximal control over net N mineralization by influencing soil organic matter quality throughout the soil profile independent of climate.

Game Coloured Petri Nets

DEFF Research Database (Denmark)

Westergaard, Michael

2006-01-01

This paper introduces the notion of game coloured Petri nets. This allows the modeler to explicitly model what parts of the model comprise the modeled system and what parts are the environment of the modeled system. We give the formal definition of game coloured Petri nets, a means of reachability...... analysis of this net class, and an application of game coloured Petri nets to automatically generate easy-to-understand visualizations of the model by exploiting the knowledge that some parts of the model are not interesting from a visualization perspective (i.e. they are part of the environment...

A model of regional primary production for use with coarse resolution satellite data

Science.gov (United States)

Prince, S. D.

1991-01-01

A model of crop primary production, which was originally developed to relate the amount of absorbed photosynthetically active radiation (APAR) to net production in field studies, is discussed in the context of coarse resolution regional remote sensing of primary production. The model depends on an approximately linear relationship between APAR and the normalized difference vegetation index. A more comprehensive form of the conventional model is shown to be necessary when different physiological types of plants or heterogeneous vegetation types occur within the study area. The predicted variable in the new model is total assimilation (net production plus respiration) rather than net production alone or harvest yield.

Coloured Petri Nets

DEFF Research Database (Denmark)

Jensen, Kurt

1991-01-01

This paper describes how Coloured Petri Nets (CP-nets) have been developed — from being a promising theoretical model to being a full-fledged language for the design, specification, simulation, validation and implementation of large software systems (and other systems in which human beings and...

Net zero water

CSIR Research Space (South Africa)

Lindeque, M

2013-01-01

Full Text Available the national grid. The unfortunate situation with water is that there is no replacement technology for water. Water can be supplied from many different sources. A net zero energy development will move closer to a net zero water development by reducing...

Partitioning CO₂ fluxes with isotopologue measurements and modeling to understand mechanisms of forest carbon sequestration

Energy Technology Data Exchange (ETDEWEB)

Davidson, Eric A. [Woods Hole Research Center, Falmouth, MA (United States); Saleska, Scott [Univ. of Arizona, Tucson, AZ (United States); Savage, Kathleen [Woods Hole Research Center, Falmouth, MA (United States); Finzi, Adrien [Boston Univ., MA (United States); Moorcroft, Paul [Harvard Univ., Cambridge, MA (United States); Wehr, Richard [Univ. of Arizona, Tucson, AZ (United States)

2016-02-18

1. Project Summary and Objectives This project combines automated in situ observations of the isotopologues of CO₂ with root observations, novel experimental manipulations of belowground processes, and isotope-enabled ecosystem modeling to investigate mechanisms of below- vs. aboveground carbon sequestration at the Harvard Forest Environmental Measurements Site (EMS). The proposed objectives, which have now been largely accomplished, include: A. Partitioning of net ecosystem CO₂ exchange (NEE) into photosynthesis and respiration using long-term continuous observations of the isotopic composition of NEE, and analysis of their dynamics ; B. Investigation of the influence of vegetation phenology on the timing and magnitude of carbon allocated belowground using measurements of root growth and indices of belowground autotrophic vs. heterotrophic respiration (via trenched plots and isotope measurements); C. Testing whether plant allocation of carbon belowground stimulates the microbial decomposition of soil organic matter, using in situ rhizosphere simulation experiments wherein realistic quantities of artificial isotopically-labeled exudates are released into the soil; and D. Synthesis and interpretation of the above data using the Ecosystem Demography Model 2 (ED2).

Towards new information resources for public health--from WordNet to MedicalWordNet.

Science.gov (United States)

Fellbaum, Christiane; Hahn, Udo; Smith, Barry

2006-06-01

In the last two decades, WordNet has evolved as the most comprehensive computational lexicon of general English. In this article, we discuss its potential for supporting the creation of an entirely new kind of information resource for public health, viz. MedicalWordNet. This resource is not to be conceived merely as a lexical extension of the original WordNet to medical terminology; indeed, there is already a considerable degree of overlap between WordNet and the vocabulary of medicine. Instead, we propose a new type of repository, consisting of three large collections of (1) medically relevant word forms, structured along the lines of the existing Princeton WordNet; (2) medically validated propositions, referred to here as medical facts, which will constitute what we shall call MedicalFactNet; and (3) propositions reflecting laypersons' medical beliefs, which will constitute what we shall call the MedicalBeliefNet. We introduce a methodology for setting up the MedicalWordNet. We then turn to the discussion of research challenges that have to be met to build this new type of information resource. We build a database of sentences relevant to the medical domain. The sentences are generated from WordNet via its relations as well as from medical statements broken down into elementary propositions. Two subcorpora of sentences are distinguished, MedicalBeliefNet and MedicalFactNet. The former is rated for assent by laypersons; the latter for correctness by medical experts. The sentence corpora will be valuable for a variety of applications in information retrieval as well as in research in linguistics and psychology with respect to the study of expert and non-expert beliefs and their linguistic expressions. Our work has to meet several considerable challenges. These include accounting for the distinction between medical experts and laypersons, the social issues of expert-layperson communication in different media, the linguistic aspects of encoding medical knowledge, and

Multiflavor string-net models

Science.gov (United States)

Lin, Chien-Hung

2017-05-01

We generalize the string-net construction to multiple flavors of strings, each of which is labeled by the elements of an Abelian group Gi. The same flavor of strings can branch, while different flavors of strings can cross one another and thus they form intersecting string nets. We systematically construct the exactly soluble lattice Hamiltonians and the ground-state wave functions for the intersecting string-net condensed phases. We analyze the braiding statistics of the low-energy quasiparticle excitations and find that our model can realize all the topological phases as the string-net model with group G =∏iGi . In this respect, our construction provides various ways of building lattice models which realize topological order G , corresponding to different partitions of G and thus different flavors of string nets. In fact, our construction concretely demonstrates the Künneth formula by constructing various lattice models with the same topological order. As an example, we construct the G =Z2×Z2×Z2 string-net model which realizes a non-Abelian topological phase by properly intersecting three copies of toric codes.

Rare, but challenging tumors: NET

International Nuclear Information System (INIS)

Ivanova, D.; Balev, B.

2013-01-01

Full text: Introduction: Gastroenteropancreatic Neuroendocrine Tumors (GEP - NET) are a heterogeneous group of tumors with different locations and many different clinical, histological, and imaging performance. In a part of them a secretion of various organic substances is present. The morbidity of GEP - NET in the EU is growing, and this leads to increase the attention to them. What you will learn: Imaging methods used for localization and staging of GEP - NET, characteristics of the study’s protocols; Classification of GEP - NET; Demonstration of typical and atypical imaging features of GEP - NET in patients registered at the NET Center at University Hospital ‘St. Marina’, Varna; Features of metastatic NET, The role of imaging in the evaluation of treatment response and follow-up of the patients. Discussion: The image semiotics analysis is based on 19 cases of GEP - NET registered NET Center at University Hospital ‘St. Marina’. The main imaging method is multidetector CT (MDCT), and magnetic resonance imaging (MRI ) has advantages in the evaluation of liver lesions and the local prevalence of anorectal tumors. In patients with advanced disease and liver lesions the assessment of skeletal involvement (MRI/ nuclear medical method) is mandatory. The majority of GEP - NET have not any specific imaging findings. Therefore it is extremely important proper planning and conducting of the study (MDCT and MR enterography; accurate assessment phase of scanning, positive and negative contrast). Conclusion: GEP - NET is a major diagnostic challenge due to the absence of typical imaging characteristics and often an overlap with those of the tumors of different origin can be observed. Therefore, a good knowledge of clinical and imaging changes occurring at different locations is needed. MDCT is the basis for the diagnosis, staging and follow-up of these neoplasms

Limitations of shallow nets approximation.

Science.gov (United States)

Lin, Shao-Bo

2017-10-01

In this paper, we aim at analyzing the approximation abilities of shallow networks in reproducing kernel Hilbert spaces (RKHSs). We prove that there is a probability measure such that the achievable lower bound for approximating by shallow nets can be realized for all functions in balls of reproducing kernel Hilbert space with high probability, which is different with the classical minimax approximation error estimates. This result together with the existing approximation results for deep nets shows the limitations for shallow nets and provides a theoretical explanation on why deep nets perform better than shallow nets. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reduction of net primary productivity in southern China caused by abnormal low-temperature freezing in winter of 2008 detected by a remote sensing-driven ecosystem model

Science.gov (United States)

Ju, W.; Liu, Y.; Zhou, Y.; Zhu, G.

2011-12-01

Terrestrial carbon cycle is an important determinant of global climate change and affected by various factors, including climate, CO2 concentration, atmospheric nitrogen deposition and human activities. Extreme weather events can significantly regulate short-term even long-term carbon exchanges between terrestrial ecosystems and the atmosphere. During the period from the middle January to the middle February 2008, Southern China was seriously hit by abnormal low-temperature freezing, which caused serous damages to forests and crops. However, the reduction of net primary productivity (NPP) of terrestrial ecosystems caused by this extremely abnormal weather event has not been quantitatively investigated. In this study, the Boreal Ecosystem Productivity Simulator (BEPS) model was employed to assess the reduction of NPP in Southern China caused by the abnormal low-temperature freezing. Prior to the regional simulation, the BEPS model was validated using measured NPP in different ecosystems, demonstrating the ability of this model to simulate NPP reliably in China. Then, it was forced using meteorological data interpolated from observations of weather stations and leaf area index inversed from MODIS reflectance data to simulate national wide NPP at a 500 m resolution for the period from 2003 to 2008. The departures of NPP in 2008 from the means during 2003-2007 were used as the indicator of NPP reduction caused by the low-temperature freezing. It was found out that NPP in 2008 decreased significantly in forests of Southern China, especially in Guangdong, Fujian, Zhejiang, Guangxi, Jiangxi, and Hunan Provinces, in which the low-temperature freeing was more serious. The annul reduction of NPP was above 150 g C/m^2/yr in these areas. Key words: Net Primary Productivity, low-temperature freezing, BEPS model, MODIS Correspondence author: Weimin Ju Email:juweimin@nju.edu.cn

Belowground Carbon Allocation and Plant-Microbial Interactions Drive Resistance and Resilience of Mountain Grassland Communities to Drought

Science.gov (United States)

Karlowsky, S.; Augusti, A.; Ingrisch, J.; Hasibeder, R.; Lavorel, S.; Bahn, M.; Gleixner, G.

2016-12-01

Belowground carbon allocation (BCA) and plant-microbial interactions are crucial for the functioning of terrestrial ecosystems. Recent research suggests that extreme events can have severe effects on these processes but it is unknown how land use intensity potentially modifies their responses. We studied the resistance and resilience of mountain grassland communities to prolonged drought and investigated the role of plant C allocation and soil microbial communities in mediating drought resistance and immediate recovery. In a common garden experiment we exposed monoliths from an abandoned grassland and a hay meadow to an early summer drought. Two independent 13C pulse labeling experiments were conducted, the first during peak drought and the second during the recovery phase. The 13C incorporation was analyzed in above- and belowground plant parts and in phospho- and neutral lipid fatty acids of soil microorganisms. In addition, a 15N label was added at the rewetting to determine plant N uptake. We found that C uptake, BCA and C transfer to soil microorganisms were less strongly reduced by drought in the abandoned grassland than in the meadow. Moreover, drought induced an increase of arbuscular mycorrhiza fungi (AMF) marker in the abandoned grassland. Nevertheless, C uptake and related parameters were quickly recovered and N uptake increased in the meadow during recovery. Unexpectedly, AMF and their C uptake were generally reduced during recovery, while bacteria increased and quickly recovered C uptake, particularly in the meadow. Our results showed a negative relation between high resistance and fast recovery. The more resistant abandoned grassland plant communities seemed to invest more C below ground and into interactions with AMF during drought, likely to access water through their hyphal network. Conversely, meadow communities invested more C from recent photosynthesis into bacterial communities during recovery, obviously to gain more nutrients for regrowth

The effect of netting solidity ratio and inclined angle on the hydrodynamic characteristics of knotless polyethylene netting

Science.gov (United States)

Tang, Hao; Hu, Fuxiang; Xu, Liuxiong; Dong, Shuchuang; Zhou, Cheng; Wang, Xuefang

2017-10-01

Knotless polyethylene (PE) netting has been widely used in aquaculture cages and fishing gears, especially in Japan. In this study, the hydrodynamic coefficient of six knotless PE netting panels with different solidity ratios were assessed in a flume tank under various attack angles of netting from 0° (parallel to flow) to 90° (perpendicular to flow) and current speeds from 40 cm s-1 to 130 cm s-1. It was found that the drag coefficient was related to Reynolds number, solidity ratio and attack angle of netting. The solidity ratio was positively related with drag coefficient for netting panel perpendicular to flow, whereas when setting the netting panel parallel to the flow the opposite result was obtained. For netting panels placed at an angle to the flow, the lift coefficient reached the maximum at an attack angle of 50° and then decreased as the attack angle further increased. The solidity ratio had a dual influence on drag coefficient of inclined netting panels. Compared to result in the literature, the normal drag coefficient of knotless PE netting measured in this study is larger than that of nylon netting or Dyneema netting.

Use of bed nets and factors that influence bed net use among Jinuo Ethnic Minority in southern China.

Science.gov (United States)

Xu, Jian-wei; Liao, Yuan-mei; Liu, Hui; Nie, Ren-hua; Havumaki, Joshua

2014-01-01

Insecticide-treated nets (ITNs) are an integral part of vector control recommendations for malaria elimination in China. This study investigated the extent to which bed nets were used and which factors influence bed net use among Jinuo Ethnic Minority in China-Myanmar-Laos border areas. This study combined a quantitative household questionnaire survey and qualitative semi-structured in-depth interviews (SDI). Questionnaires were administered to 352 heads of households. SDIs were given to 20 key informants. The bed net to person ratio was 1∶2.1 (i.e., nearly one net for every two people), however only 169 (48.0%) households owned at least one net and 623 (47.2%) residents slept under bed nets the prior night. The percentages of residents who regularly slept under nets (RSUN) and slept under nets the prior night (SUNPN) were similar (48.0% vs. 47.2%, P>0.05), however the percentage correct use of nets (CUN) was significantly lower (34.5%, Pcash income per person (ACIP) was an independent factor that influenced bed net use (PHigh bed net availability does not necessarily mean higher coverage or bed net use. Household income, house type and knowledge of the ability of bed nets to prevent malaria are all independent factors that influence bed net use among Jinuo Ethnic Minority.

Fusion through the NET

International Nuclear Information System (INIS)

Spears, B.

1987-01-01

The paper concerns the next generation of fusion machines which are intended to demonstrate the technical viability of fusion. In Europe, the device that will follow on from JET is known as NET - the Next European Torus. If the design programme for NET proceeds, Europe could start to build the machine in 1994. The present JET programme hopes to achieve breakeven in the early 1990's. NET hopes to reach ignition in the next century, and so lay the foundation for a demonstration reactor. A description is given of the technical specifications of the components of NET, including: the first wall, the divertors to protect the wall, the array of magnets that provide the fields containing the plasma, the superconducting magnets, and the shield of the machine. NET's research programme is briefly outlined, including the testing programme to optimise conditions in the machine to achieve ignition, and its safety work. (U.K.)

Belowground ectomycorrhizal fungal communities respond to liming in three southern Swedish coniferous forest stands

DEFF Research Database (Denmark)

Kjøller, Rasmus; Clemmensen, Karina

2009-01-01

In this study we report on changes in the belowground ectomycorrhizal fungal communities in southern Swedish coniferous forests as a consequence of liming with 3-7 ton limestone per hectare 16 years prior to the study. A total of 107 ectomycorrhizal fungi were identified from 969 independently...... sampled root tips by sequencing the internal transcribed spacer region of the ribosomal DNA. Forty, 59 and 51 species were identified in three pine and spruce forests. Within all sites only about 25% of the species overlapped between the limed and the reference areas. However, the most abundant species...... were often found in both limed and reference plots and 60-70% of the root tips at each site were colonised by species occurring in both limed and reference plots. Across all three sites, fungal species belonging to the genus Tylospora and the order Pezizales became significantly more frequent in limed...

NetView technical research

Science.gov (United States)

1993-01-01

This is the Final Technical Report for the NetView Technical Research task. This report is prepared in accordance with Contract Data Requirements List (CDRL) item A002. NetView assistance was provided and details are presented under the following headings: NetView Management Systems (NMS) project tasks; WBAFB IBM 3090; WPAFB AMDAHL; WPAFB IBM 3084; Hill AFB; McClellan AFB AMDAHL; McClellan AFB IBM 3090; and Warner-Robins AFB.

Efficacy of PermaNet® 3.0 and PermaNet® 2.0 nets against laboratory-reared and wild Anopheles gambiae sensu lato populations in northern Tanzania.

Science.gov (United States)

Kweka, Eliningaya J; Lyaruu, Lucile J; Mahande, Aneth M

2017-01-18

Mosquitoes have developed resistance against pyrethroids, the only class of insecticides approved for use on long-lasting insecticidal nets (LLINs). The present study sought to evaluate the efficacy of the pyrethroid synergist PermaNet® 3.0 LLIN versus the pyrethroid-only PermaNet® 2.0 LLIN, in an East African hut design in Lower Moshi, northern Tanzania. In this setting, resistance to pyrethroid insecticides has been identified in Anopheles gambiae mosquitoes. Standard World Health Organization bioefficacy evaluations were conducted in both laboratory and experimental huts. Experimental hut evaluations were conducted in an area where there was presence of a population of highly pyrethroid-resistant An. arabiensis mosquitoes. All nets used were subjected to cone bioassays and then to experimental hut trials. Mosquito mortality, blood-feeding inhibition and personal protection rate were compared between untreated nets, unwashed LLINs and LLINs that were washed 20 times. Both washed and unwashed PermaNet® 2.0 and PermaNet® 3.0 LLINs had knockdown and mortality rates of 100% against a susceptible strain of An. gambiae sensu stricto. The adjusted mortality rate of the wild mosquito population after use of the unwashed PermaNet® 3.0 and PermaNet® 2.0 nets was found to be higher than after use of the washed PermaNet® 2.0 and PermaNet® 3.0 nets. Given the increasing incidence of pyrethroid resistance in An. gambiae mosquitoes in Tanzania, we recommend that consideration is given to its distribution in areas with pyrethroid-resistant malaria vectors within the framework of a national insecticide-resistance management plan.

Plant functional traits and soil carbon sequestration in contrasting biomes.

NARCIS (Netherlands)

De Deyn, G.B.; Cornelissen, J.H.C.; Bardgett, R.D.

2008-01-01

Plant functional traits control a variety of terrestrial ecosystem processes, including soil carbon storage which is a key component of the global carbon cycle. Plant traits regulate net soil carbon storage by controlling carbon assimilation, its transfer and storage in belowground biomass, and its

Belowground Carbon Allocation to Ectomycorrhizal Fungi Links Biogeochemical Cycles of Boron and Nitrogen

Science.gov (United States)

Lucas, R. W.; Högberg, P.; Ingri, J. N.

2011-12-01

Boron (B) is an essential micronutrient to most trees and represents an important limiting resource in some regions, deficient trees experiencing the loss of apical dominance, altered stem growth, and even tree death in extreme cases. Similar to the acquisition of most soil nutrients, B is likely supplied to host trees by mycorrhizal symbionts in exchange for recently fixed carbohydrates. In this way, belowground allocation of photosynthate, which drives the majority of biological processes belowground, links the biogeochemical cycles of B and nitrogen (N). Using a long-term N addition experiment in a Pinus sylvestris forest that has been ongoing for 41 years, we examined how the availability of inorganic N mediates the response of B isotopes in the tree needles, organic soil, and fungal pools in a boreal forest in northern Sweden. Using archived needle samples collected annually from the current year's needle crop, we observed δ11B to increase from 30.8 (0.5 se) to 41.8 (0.7 se)% in N fertilized plots from 1970 to 1979, a period of increasing B deficiency stress induced by N fertilization; the concentration of B in tree needles during 1979 dropping as low as 3.0 μg g-2. During the same period, B concentrations in tree needles from control plots remained relatively unchanged and δ11B remained at a steady state value of 34.1 (1.0 se)%. Following a distinct, large-scale, pulse labeling event in 1980 in which 2.5 kg ha-1 of isotopically distinct B was applied to all treatment and control plots to alleviate the N-induced B deficiency, concentrations of B in current needles increased immediately in all treatments, the magnitude of the response being dependent upon the N treatment. But unlike other pool dilution studies, δ11B of current tree needles did not return to pre-addition, steady-state levels. Instead, δ11B continued to decrease over time in both N addition and control treatments. This unexpected pattern has not been previously described but can be explained

PODATKOVNE STORITVE ADO.NET IN ADO.NET ENTITY FRAMEWORK

OpenAIRE

Volavc, Franc

2012-01-01

V diplomskem delu smo predstavili Microsoftovi ogrodji ADO.NET in ADO.NET Entity Framework. Preučili in analizirali smo metode za dostop do podatkovnih virov, ki jih ponujata ogrodji, ter nato te ugotovitve preslikati v odločitveno drevo, katero bo programerjem in razvijalcem informacijskih sistemov pomagalo pri odločanju glede pristopa za dostop do podatkovnih virov. Ker bomo v diplomskem delu predstavili Microsoftovi ogrodji, bomo posledično omejeni zgolj na Microsoftovo tehnologijo, se pra...

Blanket testing in NET

International Nuclear Information System (INIS)

Chazalon, M.; Daenner, W.; Libin, B.

1989-01-01

The testing stages in NET for the performance assessment of the various breeding blanket concepts developed at the present time in Europe for DEMO (LiPb and ceramic blankets) and the requirements upon NET to perform these tests are reviewed. Typical locations available in NET for blanket testing are the central outboard segments and the horizontal ports of in-vessel sectors. These test positions will be connectable with external test loops. The number of test loops (helium, water, liquid metal) will be such that each major class of blankets can be tested in NET. The test positions, the boundary conditions and the external test loops are identified and the requirements for test blankets are summarized (author). 6

Divergence in Forest-Type Response to Climate and Weather: Evidence for Regional Links Between Forest-Type Evenness and Net Primary Productivity

Science.gov (United States)

Bradford, J.B.

2011-01-01

Climate change is altering long-term climatic conditions and increasing the magnitude of weather fluctuations. Assessing the consequences of these changes for terrestrial ecosystems requires understanding how different vegetation types respond to climate and weather. This study examined 20 years of regional-scale remotely sensed net primary productivity (NPP) in forests of the northern Lake States to identify how the relationship between NPP and climate or weather differ among forest types, and if NPP patterns are influenced by landscape-scale evenness of forest-type abundance. These results underscore the positive relationship between temperature and NPP. Importantly, these results indicate significant differences among broadly defined forest types in response to both climate and weather. Essentially all weather variables that were strongly related to annual NPP displayed significant differences among forest types, suggesting complementarity in response to environmental fluctuations. In addition, this study found that forest-type evenness (within 8 ?? 8 km2 areas) is positively related to long-term NPP mean and negatively related to NPP variability, suggesting that NPP in pixels with greater forest-type evenness is both higher and more stable through time. This is landscape- to subcontinental-scale evidence of a relationship between primary productivity and one measure of biological diversity. These results imply that anthropogenic or natural processes that influence the proportional abundance of forest types within landscapes may influence long-term productivity patterns. ?? 2011 Springer Science+Business Media, LLC (outside the USA).

The influence of health policy and market factors on the hospital safety net.

Science.gov (United States)

Bazzoli, Gloria J; Lindrooth, Richard C; Kang, Ray; Hasnain-Wynia, Romana

2006-08-01

To examine how the financial pressures resulting from the Balanced Budget Act (BBA) of 1997 interacted with private sector pressures to affect indigent care provision. American Hospital Association Annual Survey, Area Resource File, InterStudy Health Maintenance Organization files, Current Population Survey, and Bureau of Primary Health Care data. We distinguished core and voluntary safety net hospitals in our analysis. Core safety net hospitals provide a large share of uncompensated care in their markets and have large indigent care patient mix. Voluntary safety net hospitals provide substantial indigent care but less so than core hospitals. We examined the effect of financial pressure in the initial year of the 1997 BBA on uncompensated care for three hospital groups. Data for 1996-2000 were analyzed using approaches that control for hospital and market heterogeneity. All urban U.S. general acute care hospitals with complete data for at least 2 years between 1996 and 2000, which totaled 1,693 institutions. Core safety net hospitals reduced their uncompensated care in response to Medicaid financial pressure. Voluntary safety net hospitals also responded in this way but only when faced with the combined forces of Medicaid and private sector payment pressures. Nonsafety net hospitals did not exhibit similar responses. Our results are consistent with theories of hospital behavior when institutions face reductions in payment. They raise concern given continuing state budget crises plus the focus of recent federal deficit reduction legislation intended to cut Medicaid expenditures.

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

Science.gov (United States)

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

2016-02-01

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

Current Status and Future Prospect of K-NET and KiK-net

Science.gov (United States)

Aoi, S.; Kunugi, T.; Suzuki, W.; Nakamura, H.; Fujiwara, H.

2014-12-01

During 18 years since the deployment of K-NET following the Kobe earthquake, our attention has mainly focused on rapidity of the data collection and an unfailing and reliable observation. In this presentation, we review three generations of the instruments employed by K-NET and KiK-net from these two points of view.At beginning of the 2000's, we newly developed the second generation instruments (K-NET02, K-NET02A, KiK-net06) to replace the first generation instruments (K-NET95, SMAC-MDK) employed when the networks were constructed in the 1990's. These instruments have an automatic dial-out function. It takes typically 2-5 s to establish communication and a few seconds to send the pre-trigger data. After that, data is available typically within a 1.5 s delay. Not only waveform data but also strong motion indexes such as real-time intensity, PGA, PGV, PGD, and response spectra are continuously sent once a second.After the 2011 Tohoku earthquake, we have developed the third generation instruments (K-NET11, KiK-net11) and have replaced almost half of the all stations country wide. Main improvement of this instrument is more unfailing and reliable observation. Because we have often experienced very large ground motions (e.g. 45 records exceeding gravity), the maximum measureable range was expanded from 2000 gal to 4000 gal for the second generation instrument, and to 8000 gal for the third. For the third generation instrument, in case of power failure, observation (including transmission of data) works for seven days thanks to the backup battery, while for the second generation instruments it works only for one day. By adding an oblique component to the three-component accelerometers, we could automatically distinguish shaking data from noise such as electric pulses which may cause a false alarm in EEW. Implementation to guarantee the continuity of observation under severe conditions such as during the Tohoku earthquake is very important, as well as a highly efficient

Agricultural net primary production in relation to that liberated by the extinction of Pleistocene mega-herbivores: an estimate of agricultural carrying capacity?

Energy Technology Data Exchange (ETDEWEB)

Doughty, Christopher E; Field, Christopher B, E-mail: chris.doughty@ouce.ox.ac.uk, E-mail: cfield@ciw.edu [Department of Global Ecology, Carnegie Institution, Stanford, CA 94305 (United States)

2010-10-15

Mega-fauna (defined as animals > 44 kg) experienced a global extinction with 97 of 150 genera going extinct by {approx} 10 000 years ago. We estimate the net primary production (NPP) that was liberated following the global extinction of these mega-herbivores. We then explore how humans, through agriculture, gradually appropriated this liberated NPP, with specific calculations for 800, 1850, and 2000 AD. By 1850, most of the liberated NPP had been appropriated by people, but NPP was still available in the Western US, South America and Australia. NPP liberated following the extinction of the mega-herbivores was {approx} 2.5% ({approx}1.4 (between 1.2 and 1.6) Pg yr{sup -1} of 56 Pg C yr{sup -1}; Pg: petagrams) of global terrestrial NPP. Liberated NPP peaked during the onset of agriculture and was sufficient for sustaining human agriculture until {approx} 320 (250-500) years ago. Humans currently use {approx} 6 times more NPP than was utilized by the extinct Pleistocene mega-herbivores.

Agricultural net primary production in relation to that liberated by the extinction of Pleistocene mega-herbivores: an estimate of agricultural carrying capacity?

International Nuclear Information System (INIS)

Doughty, Christopher E; Field, Christopher B

2010-01-01

Mega-fauna (defined as animals > 44 kg) experienced a global extinction with 97 of 150 genera going extinct by ∼ 10 000 years ago. We estimate the net primary production (NPP) that was liberated following the global extinction of these mega-herbivores. We then explore how humans, through agriculture, gradually appropriated this liberated NPP, with specific calculations for 800, 1850, and 2000 AD. By 1850, most of the liberated NPP had been appropriated by people, but NPP was still available in the Western US, South America and Australia. NPP liberated following the extinction of the mega-herbivores was ∼ 2.5% (∼1.4 (between 1.2 and 1.6) Pg yr -1 of 56 Pg C yr -1 ; Pg: petagrams) of global terrestrial NPP. Liberated NPP peaked during the onset of agriculture and was sufficient for sustaining human agriculture until ∼ 320 (250-500) years ago. Humans currently use ∼ 6 times more NPP than was utilized by the extinct Pleistocene mega-herbivores.

Belowground Carbon Cycling Processes at the Molecular Scale: An EMSL Science Theme Advisory Panel Workshop

Energy Technology Data Exchange (ETDEWEB)

Hess, Nancy J.; Brown, Gordon E.; Plata, Charity

2014-02-21

As part of the Belowground Carbon Cycling Processes at the Molecular Scale workshop, an EMSL Science Theme Advisory Panel meeting held in February 2013, attendees discussed critical biogeochemical processes that regulate carbon cycling in soil. The meeting attendees determined that as a national scientific user facility, EMSL can provide the tools and expertise needed to elucidate the molecular foundation that underlies mechanistic descriptions of biogeochemical processes that control carbon allocation and fluxes at the terrestrial/atmospheric interface in landscape and regional climate models. Consequently, the workshop's goal was to identify the science gaps that hinder either development of mechanistic description of critical processes or their accurate representation in climate models. In part, this report offers recommendations for future EMSL activities in this research area. The workshop was co-chaired by Dr. Nancy Hess (EMSL) and Dr. Gordon Brown (Stanford University).

Initial CAD investigations for NET

International Nuclear Information System (INIS)

Katz, F.; Leinemann, K.; Ludwig, A.; Marek, U.; Olbrich, W.; Schlechtendahl, E.G.

1985-11-01

This report summarizes the work done under contract no. 164/84-7/FU-D-/NET between the Commission of the European Communities and KfK during the period from June 1, 1984, through May 31, 1985. The following topics are covered in this report: Initial modelling of NET version NET2A, CAD system extension for remote handling studies, analysis of the CAD information structure, work related to the transfer of CAD information between KfK and the NET team. (orig.) [de

Organic carbon balance and net ecosystem metabolism in Chesapeake Bay

Science.gov (United States)

Kemp, W.M.; Smith, E.M.; Marvin-DiPasquale, M.; Boynton, W.R.

1997-01-01

The major fluxes of organic carbon associated with physical transport and biological metabolism were compiled, analyzed and compared for the mainstem portion of Chesapeake Bay (USA). In addition, 5 independent methods were used to calculate the annual mean net ecosystem metabolism (NEM = production - respiration) for the integrated Bay. These methods, which employed biogeochemical models, nutrient mass-balances anti summation of individual organic carbon fluxes, yielded remarkably similar estimates, with a mean NEM of +50 g C m-2 yr-1 (?? SE = 751, which is approximately 8% of the estimated annual average gross primary production. These calculations suggest a strong cross-sectional pattern in NEM throughout the Bay, wherein net heterotrophic metabolism prevails in the pelagic zones of the main channel, while net autotrophy occurs in the littoral zones which flank the deeper central area. For computational purposes, the estuary was separated into 3 regions along the land-sea gradient: (1) the oligohaline Upper Bay (11% of total area); (2) the mesohaline Mid Bay (36% of area); and (3) the polyhaline Lower Bay (53% of area). A distinct regional trend in NEM was observed along this salinity gradient, with net here(atrophy (NEM = 87 g C m-2 yr-1) in the Upper Bay, balanced metabolism in the Mid Bay and net autotrophy (NEM = +92 g C m-2 yr-1) in the Lower Bay. As a consequence of overall net autotrophy, the ratio of dissolved inorganic nitrogen (DIN) to total organic nitrogen (TON) changed from DIN:TON = 5.1 for riverine inputs to DIN:TON = 0.04 for water exported to the ocean. A striking feature of this organic C mass-balance was the relative dominance of biologically mediated metabolic fluxes compared to physical transport fluxes. The overall ratio of physical TOC inputs (1) to biotic primary production (P) was 0.08 for the whole estuary, but varied dramatically from 2.3 in the Upper Bay to 0.03 in the Mid and Lower Bay regions. Similarly, ecosystem respiration was

MetNet - In situ observational Network and Orbital platform to investigate the Martian environment

Science.gov (United States)

Harri, Ari-Matti; Leinonen, Jussi; Merikallio, Sini; Paton, Mark; Haukka, Harri; Polkko, Jouni

2007-09-01

MetNet Mars Mission is an in situ observational network and orbital platform mission to investigate the Martian environment and it has been proposed to European Space Agency in response to Call for proposals for the first planning cycle of Cosmic Vision 2015-2025 D/SCI/DJS/SV/val/21851. The MetNet Mars Mission is to be implemented in collaboration with ESA, FMI, LA, IKI and the payload providing science teams. The scope of the MetNet Mission is to deploy 16 MetNet Landers (MNLs) on the Martian surface by using inflatable descent system structures accompanied by an atmospheric sounder and data relay onboard the MetNet Orbiter (MNO), which is based on ESA Mars Express satellite platform. The MNLs are attached on the three sides of the satellite and most of the MNLs are deployed to Mars separately a few weeks prior to the arrival to Mars. The MetNet Orbiter will perform continuous atmospheric soundings thus complementing the accurate in situ observations at the Martian ground produced by the MetNet observation network, as well as the orbiter will serve as the primary data relay between the MetNet Landers and the Earth. The MNLs are equipped with a versatile science payload focused on the atmospheric science of Mars. Detailed characterisation of the Martian atmospheric circulation patterns, boundary layer phenomena, and climatological cycles, as well as interior investigations, require simultaneous in situ meteorological, seismic and magnetic measurements from networks of stations on the Martian surface. MetNet Mars Mission will also provide a crucial support for the safety of large landing missions in general and manned Mars missions in particular. Accurate knowledge of atmospheric conditions and weather data is essential to guarantee safe landings of the forthcoming Mars mission elements.

NetBeans IDE 8 cookbook

CERN Document Server

Salter, David

2014-01-01

If you're a Java developer of any level using NetBeans and want to learn how to get the most out of NetBeans, then this book is for you. Learning how to utilize NetBeans will provide a firm foundation for your Java application development.

The Net Advance of Physics

Science.gov (United States)

THE NET ADVANCE OF PHYSICS Review Articles and Tutorials in an Encyclopædic Format Established 1995 [Link to MIT] Computer support for The Net Advance of Physics is furnished by The Massachusetts Newest Additions SPECIAL FEATURES: Net Advance RETRO: Nineteenth Century Physics History of Science

County community health associations of net voting shift in the 2016 U.S. presidential election.

Science.gov (United States)

Wasfy, Jason H; Stewart, Charles; Bhambhani, Vijeta

2017-01-01

In the U.S. presidential election of 2016, substantial shift in voting patterns occurred relative to previous elections. Although this shift has been associated with both education and race, the extent to which this shift was related to public health status is unclear. To determine the extent to which county community health was associated with changes in voting between the presidential elections of 2016 and 2012. Ecological study with principal component analysis (PCA) using principal axis method to extract the components, then generalized linear regression. General community. All counties in the United States. Physically unhealthy days, mentally unhealthy days, percent food insecure, teen birth rate, primary care physician visit rate, age-adjusted mortality rate, violent crime rate, average health care costs, percent diabetic, and percent overweight or obese. The percentage of Donald Trump votes in 2016 minus percentage of Mitt Romney votes in 2012 ("net voting shift"). Complete public health data was available for 3,009 counties which were included in the analysis. The mean net voting shift was 5.4% (+/- 5.8%). Of these 3,009 counties, 2,641 (87.8%) had positive net voting shift (shifted towards Trump) and 368 counties (12.2%) had negative net voting shift (shifted away from Trump). The first principal component ("unhealthy score") accounted for 68% of the total variance in the data. The unhealthy score included all health variables except primary care physician rate, violent crime rate, and health care costs. The mean unhealthy score for counties was 0.39 (SD 0.16). Higher normalized unhealthy score was associated with positive net voting shift (22.1% shift per unit unhealthy, p Donald Trump in 2016 relative to Mitt Romney in 2012 and measures of poor public health. Although these results do not demonstrate causality, these results suggest a possible role for health status in political choices.

Improved netting

International Nuclear Information System (INIS)

Bramley, A.; Clabburn, R.J.T.

1976-01-01

A method is described for producing netting composed of longitudinal and transverse threads of irradiation cross linked thermoplastic material, the threads being joined together at their crossings by moulded masses of cross linked thermoplastic material. The thread may be formed of polyethylene filaments, subjected to a radiation dose of 15 to 25 MR. The moulding can be conducted at 245 0 to 260 0 C or higher. The product is claimed to be an improved quality of netting, with bonds of increased strength between crossing threads. (U.K.)

Estimation of net primary productivity using a process-based model in Gansu Province, Northwest China

Energy Technology Data Exchange (ETDEWEB)

Wang, Peijuan; Xie, Donghui; Zhou, Yuyu; E, Youhao; Zhu, Qijiang

2014-01-16

The ecological structure in the arid and semi-arid region of Northwest China with forest, grassland, agriculture, Gobi, and desert, is complex, vulnerable, and unstable. It is a challenging and sustaining job to keep the ecological structure and improve its ecological function. Net primary productivity (NPP) modeling can help to improve the understanding of the ecosystem, and therefore, improve ecological efficiency. The boreal ecosystem productivity simulator (BEPS) model provides the possibility of NPP modeling in terrestrial ecosystem, but it has some limitations for application in arid and semi-arid regions. In this paper we improve the BEPS model, in terms of its water cycle by adding the processes of infiltration and surface runoff, to be applicable in arid and semi-arid regions. We model the NPP of forest, grass, and crop in Gansu Province as an experimental area in Northwest China in 2003 using the improved BEPS model, parameterized with moderate resolution remote sensing imageries and meteorological data. The modeled NPP using improved BEPS agrees better with the ground measurements in Qilian Mountain than that with original BEPS, with a higher R2 of 0.746 and lower root mean square error (RMSE) of 46.53 gC/m2 compared to R2 of 0.662 and RMSE of 60.19 gC/m2 from original BEPS. The modeled NPP of three vegetation types using improved BEPS show evident differences compared to that using original BEPS, with the highest difference ratio of 9.21% in forest and the lowest value of 4.29% in crop. The difference ratios between different vegetation types lie on the dependence on natural water sources. The modeled NPP in five geographic zones using improved BEPS are higher than those with original BEPS, with higher difference ratio in dry zones and lower value in wet zones.

A new framework for evaluating the impacts of drought on net primary productivity of grassland.

Science.gov (United States)

Lei, Tianjie; Wu, Jianjun; Li, Xiaohan; Geng, Guangpo; Shao, Changliang; Zhou, Hongkui; Wang, Qianfeng; Liu, Leizhen

2015-12-01

This paper presented a valuable framework for evaluating the impacts of droughts (single factor) on grassland ecosystems. This framework was defined as the quantitative magnitude of drought impact that unacceptable short-term and long-term effects on ecosystems may experience relative to the reference standard. Long-term effects on ecosystems may occur relative to the reference standard. Net primary productivity (NPP) was selected as the response indicator of drought to assess the quantitative impact of drought on Inner Mongolia grassland based on the Standardized Precipitation Index (SPI) and BIOME-BGC model. The framework consists of six main steps: 1) clearly defining drought scenarios, such as moderate, severe and extreme drought; 2) selecting an appropriate indicator of drought impact; 3) selecting an appropriate ecosystem model and verifying its capabilities, calibrating the bias and assessing the uncertainty; 4) assigning a level of unacceptable impact of drought on the indicator; 5) determining the response of the indicator to drought and normal weather state under global-change; and 6) investigating the unacceptable impact of drought at different spatial scales. We found NPP losses assessed using the new framework were more sensitive to drought and had higher precision than the long-term average method. Moreover, the total and average losses of NPP are different in different grassland types during the drought years from 1961-2009. NPP loss was significantly increased along a gradient of increasing drought levels. Meanwhile, NPP loss variation under the same drought level was different in different grassland types. The operational framework was particularly suited for integrative assessing the effects of different drought events and long-term droughts at multiple spatial scales, which provided essential insights for sciences and societies that must develop coping strategies for ecosystems for such events. Copyright © 2015 Elsevier B.V. All rights reserved.

Net alkalinity and net acidity 1: Theoretical considerations

International Nuclear Information System (INIS)

Kirby, Carl S.; Cravotta, Charles A.

2005-01-01

Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO 2 , and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined 'CO 2 -acidity' is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO 2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass-action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mgL -1 as CaCO 3 (based on pH and analytical concentrations of dissolved Fe II , Fe III , Mn, and Al in mgL -1 ):acidity calculated =50{1000(10 -pH )+[2(Fe II )+3(Fe III )]/56+2(Mn) /55+3(Al)/27}underestimates contributions from HSO 4 - and H + , but overestimates the acidity due to Fe 3+ and Al 3+ . However, these errors tend to approximately cancel each other. It is demonstrated that 'net alkalinity' is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the

Net alkalinity and net acidity 1: Theoretical considerations

Science.gov (United States)

Kirby, C.S.; Cravotta, C.A.

2005-01-01

Net acidity and net alkalinity are widely used, poorly defined, and commonly misunderstood parameters for the characterization of mine drainage. The authors explain theoretical expressions of 3 types of alkalinity (caustic, phenolphthalein, and total) and acidity (mineral, CO2, and total). Except for rarely-invoked negative alkalinity, theoretically defined total alkalinity is closely analogous to measured alkalinity and presents few practical interpretation problems. Theoretically defined "CO 2-acidity" is closely related to most standard titration methods with an endpoint pH of 8.3 used for determining acidity in mine drainage, but it is unfortunately named because CO2 is intentionally driven off during titration of mine-drainage samples. Using the proton condition/mass- action approach and employing graphs to illustrate speciation with changes in pH, the authors explore the concept of principal components and how to assign acidity contributions to aqueous species commonly present in mine drainage. Acidity is defined in mine drainage based on aqueous speciation at the sample pH and on the capacity of these species to undergo hydrolysis to pH 8.3. Application of this definition shows that the computed acidity in mg L -1 as CaCO3 (based on pH and analytical concentrations of dissolved FeII, FeIII, Mn, and Al in mg L -1):aciditycalculated=50{1000(10-pH)+[2(FeII)+3(FeIII)]/56+2(Mn)/ 55+3(Al)/27}underestimates contributions from HSO4- and H+, but overestimates the acidity due to Fe3+ and Al3+. However, these errors tend to approximately cancel each other. It is demonstrated that "net alkalinity" is a valid mathematical construction based on theoretical definitions of alkalinity and acidity. Further, it is shown that, for most mine-drainage solutions, a useful net alkalinity value can be derived from: (1) alkalinity and acidity values based on aqueous speciation, (2) measured alkalinity minus calculated acidity, or (3) taking the negative of the value obtained in a

Proof Nets for Lambek Calculus

NARCIS (Netherlands)

Roorda, Dirk

1992-01-01

The proof nets of linear logic are adapted to the non-commutative Lambek calculus. A different criterion for soundness of proof nets is given, which gives rise to new algorithms for proof search. The order sensitiveness of the Lambek calculus is reflected by the planarity condition on proof nets;

Properties of porous netted materials

International Nuclear Information System (INIS)

Daragan, V.D.; Drozdov, B.G.; Kotov, A.Yu.; Mel'nikov, G.N.; Pustogarov, A.V.

1987-01-01

Hydraulic and strength characteristics, efficient heat conduction and inner heat exchange coefficient are experimentally studied for porous netted materials on the base of the brass nets as dependent on porosity, cell size and method of net laying. Results of the studies are presented. It is shown that due to anisotropy of the material properties the hydraulic resistance in the direction parallel to the nets plane is 1.3-1.6 times higher than in the perpendicular one. Values of the effective heat conduction in the direction perpendicular to the nets plane at Π>0.45 agree with the data from literature, at Π<0.45 a deviation from the calculated values is marked in the direction of the heat conduction decrease

Summarizing primary and secondary effects

DEFF Research Database (Denmark)

Karlson, Kristian Bernt

2013-01-01

Current methods for decomposing class differentials in educational decisions into primary and secondary effects produce many parameters, rendering them ill-equipped for parsimonious comparisons across countries or birth cohorts. This paper develops a parametric method that provides an optimal...... summary of primary and secondary effects across discrete class origins. Under the testable assumption that the pattern of effects of class origins on academic ability is proportional to the pattern of effects of class origins on educational choice net of academic ability, the method returns a single...

Understanding Net Zero Energy Buildings

DEFF Research Database (Denmark)

Salom, Jaume; Widén, Joakim; Candanedo, José

2011-01-01

Although several alternative definitions exist, a Net-Zero Energy Building (Net ZEB) can be succinctly described as a grid-connected building that generates as much energy as it uses over a year. The “net-zero” balance is attained by applying energy conservation and efficiency measures...... and by incorporating renewable energy systems. While based on annual balances, a complete description of a Net ZEB requires examining the system at smaller time-scales. This assessment should address: (a) the relationship between power generation and building loads and (b) the resulting interaction with the power grid...

Impacts of vegetation onset time on the net primary productivity in a mountainous island in Pacific Asia

International Nuclear Information System (INIS)

Chang, Chung-Te; Wang, Hsueh-Ching; Huang, Cho-ying

2013-01-01

Vegetation phenology reflects the response of a terrestrial ecosystem to climate change. In this study, we attempt to evaluate the El Niño/La Niña-Southern Oscillation (ENSO)-associated temporal dynamics of the vegetation onset and its influence on the net primary productivity (NPP) in a subtropical island (Taiwan) of Pacific Asia. We utilized a decade-long (2001–2010) time series of photosynthetically active vegetation cover (PV) data, which were derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) reflectance data, to delineate the vegetation phenology. These data served as inputs for the phenological analysis toolbox TIMESAT. The results indicated that the delayed vegetation onset time was directly influenced by a dry spring (February and March) in which less than 40 mm of rainfall was received. This seasonal drought impeded vegetation growth in the subsequent growing season, most likely due to delayed impacts of moisture stress related to the preceding ENSO events. The significant correlations obtained between the annual MODIS NPP and both the vegetation onset time and the length of the growing season may imply that the accumulated rainfall in the spring season governs the annual NPP. The model simulations revealed that the frequency and intensity of the ENSO-related spring droughts might increase, which would result in cascading effects on the ecosystem metabolism. (letter)

History-dependent stochastic Petri nets

NARCIS (Netherlands)

Schonenberg, H.; Sidorova, N.; Aalst, van der W.M.P.; Hee, van K.M.; Pnueli, A.; Virbitskaite, I.; Voronkov, A.

2010-01-01

Stochastic Petri Nets are a useful and well-known tool for performance analysis. However, an implicit assumption in the different types of Stochastic Petri Nets is the Markov property. It is assumed that a choice in the Petri net only depends on the current state and not on earlier choices. For many

Evaluating renewable natural resources flow and net primary productivity with a GIS-Emergy approach: A case study of Hokkaido, Japan.

Science.gov (United States)

Wang, Chengdong; Zhang, Shenyan; Yan, Wanglin; Wang, Renqing; Liu, Jian; Wang, Yutao

2016-11-18

Renewable natural resources, such as solar radiation, rainfall, wind, and geothermal heat, together with ecosystem services, provide the elementary supports for the sustainable development of human society. To improve regional sustainability, we studied the spatial distributions and quantities of renewable natural resources and net primary productivity (NPP) in Hokkaido, which is the second largest island of Japan. With the help of Geographic Information System (GIS) software, distribution maps for each type of renewable natural resource were generated by kriging interpolation based on statistical records. A composite map of the flow of all types of renewable natural resources was also generated by map layer overlapping. Additionally, we utilized emergy analysis to convert each renewable flow with different attributes into a unified unit (i.e., solar equivalent joules [sej]). As a result, the spatial distributions of the flow of renewable natural resources of the Hokkaido region are presented in the form of thematic emergy maps. Thus, the areas with higher renewable emergy can be easily visualized and identified. The dominant renewable flow in certain areas can also be directly distinguished. The results can provide useful information for regional sustainable development, environmental conservation and ecological management.

Above- and Belowground Biomass Models for Trees in the Miombo Woodlands of Malawi

Directory of Open Access Journals (Sweden)

Daud J. Kachamba

2016-02-01

Full Text Available In this study we present general (multiple tree species from several sites above- and belowground biomass models for trees in the miombo woodlands of Malawi. Such models are currently lacking in the country. The modelling was based on 74 trees comprising 33 different species with diameters at breast height (dbh and total tree height (ht ranging from 5.3 to 2 cm and from 3.0 to 25.0 m, respectively. Trees were collected from four silvicultural zones covering a wide range of conditions. We tested different models including dbh, ht and wood specific gravity ( ρ as independent variables. We evaluated model performance using pseudo-R2, root mean square error (RMSE, a covariance matrix for the parameter estimates, mean prediction error (MPE and relative mean prediction error (MPE%. Computation of MPE% was based on leave-one-out cross-validation. Values of pseudo-R2 and MPE% ranged 0.82–0.97 and 0.9%–2.8%, respectively. Model performance indicated that the models can be used over a wide range of geographical and ecological conditions in Malawi.

The effect of small solar powered 'Bͻkͻͻ' net fans on mosquito net use: results from a randomized controlled cross-over trial in southern Ghana.

Science.gov (United States)

Briët, Olivier J T; Yukich, Joshua O; Pfeiffer, Constanze; Miller, William; Jaeger, Mulako S; Khanna, Nitin; Oppong, Samuel; Nardini, Peter; Ahorlu, Collins K; Keating, Joseph

2017-01-03

Long-lasting insecticidal nets (LLINs) are ineffective malaria transmission prevention tools if they are unused. Discomfort due to heat is the most commonly reported reason for not using nets, but this problem is largely unaddressed. With increasing rural electrification and the dropping price of solar power, fans could improve comfort inside nets and be affordable to populations in malaria endemic areas. Here, results are presented from a pilot randomized controlled cross-over study testing the effect of fans on LLIN use. Eighty-three households from two rural communities in Greater Accra, Ghana, randomized into three groups, participated in a 10-month cross-over trial. After a screening survey to identify eligible households, all households received new LLINs. Bͻkͻͻ net fan systems (one fan per member) were given to households in Group 1 and water filters were given to households in Group 2. At mid-point, Group 1 and 2 crossed over interventions. Households in Group 1 and 2 participated in fortnightly surveys on households' practices related to nets, fans and water filters, while households in Group 3 were surveyed only at screening, mid-point and study end. Entomological and weather data were collected throughout the study. Analysis took both 'per protocol' (PP) and 'intention to treat' (ITT) approaches. The mid- and end-point survey data from Group 1 and 2 were analysed using Firth logistic regressions. Fortnightly survey data from all groups were analysed using logistic regressions with random effects. Provision of fans to households appeared to increase net use in this study. Although the increase in net use explained by fans was not significant in the primary analyses (ITT odds ratio 3.24, p > 0.01; PP odds ratio = 1.17, p > 0.01), it was significant in secondary PP analysis (odds ratio = 1.95, p Fan use was 90-100% depending on the fortnightly visit. This pilot study could not provide definitive evidence that fans increase net use. A larger

Pro ASP.NET 4 in VB 2010

CERN Document Server

MacDonald, Matthew; Freeman, Adam; Szpuszta, Mario; Agarwal, Vidya Vrat

2010-01-01

ASP.NET 4 is the latest version of Microsoft's revolutionary ASP.NET technology. It is the principal standard for creating dynamic web pages on the Windows platform. Pro ASP.NET 4 in VB 2010 raises the bar for high-quality, practical advice on learning and deploying Microsoft's dynamic web solution. This new edition is updated with everything you need to come to grips with the latest version of ASP.NET, including coverage of ASP.NET MVC, ASP.NET AJAX 4, ASP.NET Dynamic Data, and Silverlight 3. Seasoned .NET professionals Matthew MacDonald and Mario Szpuszta explain how you can get the most fro

Long-term variation in above and belowground plant inputs alters soil organic matter biogeochemistry at the molecular-level

Science.gov (United States)

Simpson, M. J.; Pisani, O.; Lin, L.; Lun, O.; Simpson, A.; Lajtha, K.; Nadelhoffer, K. J.

2015-12-01

The long-term fate of soil carbon reserves with global environmental change remains uncertain. Shifts in moisture, altered nutrient cycles, species composition, or rising temperatures may alter the proportions of above and belowground biomass entering soil. However, it is unclear how long-term changes in plant inputs may alter the composition of soil organic matter (SOM) and soil carbon storage. Advanced molecular techniques were used to assess SOM composition in mineral soil horizons (0-10 cm) after 20 years of Detrital Input and Removal Treatment (DIRT) at the Harvard Forest. SOM biomarkers (solvent extraction, base hydrolysis and cupric (II) oxide oxidation) and both solid-state and solution-state nuclear magnetic resonance (NMR) spectroscopy were used to identify changes in SOM composition and stage of degradation. Microbial activity and community composition were assessed using phospholipid fatty acid (PLFA) analysis. Doubling aboveground litter inputs decreased soil carbon content, increased the degradation of labile SOM and enhanced the sequestration of aliphatic compounds in soil. The exclusion of belowground inputs (No roots and No inputs) resulted in a decrease in root-derived components and enhanced the degradation of leaf-derived aliphatic structures (cutin). Cutin-derived SOM has been hypothesized to be recalcitrant but our results show that even this complex biopolymer is susceptible to degradation when inputs entering soil are altered. The PLFA data indicate that changes in soil microbial community structure favored the accelerated processing of specific SOM components with littler manipulation. These results collectively reveal that the quantity and quality of plant litter inputs alters the molecular-level composition of SOM and in some cases, enhances the degradation of recalcitrant SOM. Our study also suggests that increased litterfall is unlikely to enhance soil carbon storage over the long-term in temperate forests.

NASA Net Zero Energy Buildings Roadmap

Energy Technology Data Exchange (ETDEWEB)

Pless, S.; Scheib, J.; Torcellini, P.; Hendron, B.; Slovensky, M.

2014-10-01

In preparation for the time-phased net zero energy requirement for new federal buildings starting in 2020, set forth in Executive Order 13514, NASA requested that the National Renewable Energy Laboratory (NREL) to develop a roadmap for NASA's compliance. NASA detailed a Statement of Work that requested information on strategic, organizational, and tactical aspects of net zero energy buildings. In response, this document presents a high-level approach to net zero energy planning, design, construction, and operations, based on NREL's first-hand experience procuring net zero energy construction, and based on NREL and other industry research on net zero energy feasibility. The strategic approach to net zero energy starts with an interpretation of the executive order language relating to net zero energy. Specifically, this roadmap defines a net zero energy acquisition process as one that sets an aggressive energy use intensity goal for the building in project planning, meets the reduced demand goal through energy efficiency strategies and technologies, then adds renewable energy in a prioritized manner, using building-associated, emission- free sources first, to offset the annual energy use required at the building; the net zero energy process extends through the life of the building, requiring a balance of energy use and production in each calendar year.

RESTful NET

CERN Document Server

Flanders, Jon

2008-01-01

RESTful .NET is the first book that teaches Windows developers to build RESTful web services using the latest Microsoft tools. Written by Windows Communication Foundation (WFC) expert Jon Flanders, this hands-on tutorial demonstrates how you can use WCF and other components of the .NET 3.5 Framework to build, deploy and use REST-based web services in a variety of application scenarios. RESTful architecture offers a simpler approach to building web services than SOAP, SOA, and the cumbersome WS- stack. And WCF has proven to be a flexible technology for building distributed systems not necessa

Getting to Net Zero

Energy Technology Data Exchange (ETDEWEB)

2016-09-01

The technology necessary to build net zero energy buildings (NZEBs) is ready and available today, however, building to net zero energy performance levels can be challenging. Energy efficiency measures, onsite energy generation resources, load matching and grid interaction, climatic factors, and local policies vary from location to location and require unique methods of constructing NZEBs. It is recommended that Components start looking into how to construct and operate NZEBs now as there is a learning curve to net zero construction and FY 2020 is just around the corner.

Net Zero Energy Buildings

DEFF Research Database (Denmark)

Marszal, Anna Joanna; Bourrelle, Julien S.; Gustavsen, Arild

2010-01-01

and identify possible renewable energy supply options which may be considered in calculations. Finally, the gap between the methodology proposed by each organisation and their respective national building code is assessed; providing an overview of the possible changes building codes will need to undergo......The international cooperation project IEA SHC Task 40 / ECBCS Annex 52 “Towards Net Zero Energy Solar Buildings”, attempts to develop a common understanding and to set up the basis for an international definition framework of Net Zero Energy Buildings (Net ZEBs). The understanding of such buildings...

Pro NET Best Practices

CERN Document Server

Ritchie, Stephen D

2011-01-01

Pro .NET Best Practices is a practical reference to the best practices that you can apply to your .NET projects today. You will learn standards, techniques, and conventions that are sharply focused, realistic and helpful for achieving results, steering clear of unproven, idealistic, and impractical recommendations. Pro .NET Best Practices covers a broad range of practices and principles that development experts agree are the right ways to develop software, which includes continuous integration, automated testing, automated deployment, and code analysis. Whether the solution is from a free and

Evaluation of a barrier net used to mitigate fish impingement at a Hudson River power plant intake

International Nuclear Information System (INIS)

Hutchison, J.B.; Matousek, J.A.

1988-01-01

A multifilament nylon net of 0.95-cm bar mesh was deployed as a physical barrier to fish in front of the Bowline Point power plant cooling water intake on the Hudson River from 1976 to 1985. The barrier net was deployed during the historical peak impingement months of October-May. The primary species impinged on the intake screens during this period were young-of-year and yearling white perch, striped bass, rainbow smelt, alewife, blue-back herring, and American shad, generally ranging from 5 to 10 cm in total length. When the barrier net was deployed, median impingement of all fish was 91% lower than during comparable periods before the net was installed. A mark-recapture population estimate indicated that 230,000 yearling striped bass and white perch were in the embayment outside the net in April 1982; over a 9-d study period, only 1.6% of this estimated population was impinged. Concurrent survival probability studies of fish marked and released at locations inside and outside the barrier net showed that fish released inside had 72% lower survival (P net. Gillnet catches were significantly lower inside than outside the net (P net deployment, including changes in the anchoring system, use of a debris boom, installation of an air-bubbler system to prevent ice accumulation, and sectioning of the net to facilitate removal and cleaning. 10 refs., 3 figs., 4 tabs

Land-use type and intensity differentially filter traits in above- and below-ground arthropod communities.

Science.gov (United States)

Birkhofer, Klaus; Gossner, Martin M; Diekötter, Tim; Drees, Claudia; Ferlian, Olga; Maraun, Mark; Scheu, Stefan; Weisser, Wolfgang W; Wolters, Volkmar; Wurst, Susanne; Zaitsev, Andrey S; Smith, Henrik G

2017-05-01

Along with the global decline of species richness goes a loss of ecological traits. Associated biotic homogenization of animal communities and narrowing of trait diversity threaten ecosystem functioning and human well-being. High management intensity is regarded as an important ecological filter, eliminating species that lack suitable adaptations. Below-ground arthropods are assumed to be less sensitive to such effects than above-ground arthropods. Here, we compared the impact of management intensity between (grassland vs. forest) and within land-use types (local management intensity) on the trait diversity and composition in below- and above-ground arthropod communities. We used data on 722 arthropod species living above-ground (Auchenorrhyncha and Heteroptera), primarily in soil (Chilopoda and Oribatida) or at the interface (Araneae and Carabidae). Our results show that trait diversity of arthropod communities is not primarily reduced by intense local land use, but is rather affected by differences between land-use types. Communities of Auchenorrhyncha and Chilopoda had significantly lower trait diversity in grassland habitats as compared to forests. Carabidae showed the opposite pattern with higher trait diversity in grasslands. Grasslands had a lower proportion of large Auchenorrhyncha and Carabidae individuals, whereas Chilopoda and Heteroptera individuals were larger in grasslands. Body size decreased with land-use intensity across taxa, but only in grasslands. The proportion of individuals with low mobility declined with land-use intensity in Araneae and Auchenorrhyncha, but increased in Chilopoda and grassland Heteroptera. The proportion of carnivorous individuals increased with land-use intensity in Heteroptera in forests and in Oribatida and Carabidae in grasslands. Our results suggest that gradients in management intensity across land-use types will not generally reduce trait diversity in multiple taxa, but will exert strong trait filtering within

ASP.NET web API build RESTful web applications and services on the .NET framework

CERN Document Server

Kanjilal, Joydip

2013-01-01

This book is a step-by-step, practical tutorial with a simple approach to help you build RESTful web applications and services on the .NET framework quickly and efficiently.This book is for ASP.NET web developers who want to explore REST-based services with C# 5. This book contains many real-world code examples with explanations whenever necessary. Some experience with C# and ASP.NET 4 is expected.

Intensive management modifies soil CO2 efflux in 6-year-old Pinus taeda L. stands

Science.gov (United States)

Lisa J. Samuelson; Kurt Johnsen; Tom Stokes; Weinlang Lu

2004-01-01

Intensive forestry may reduce net CO2 emission into atmosphere by storing carbon in living biomass, dead organic matter and soil, and durable wood products. Because quantification of belowground carbon dynamics is important for reliable estimation of the carbon sequestered by intensively managed plantations, we examined soil CO2...

Migration signatures across the decades: Net migration by age in U.S. counties, 1950-2010

Directory of Open Access Journals (Sweden)

Richelle L. Winkler

2015-05-01

Full Text Available Background: Migration is the primary population redistribution process in the United States. Selective migration by age, race/ethnic group, and spatial location governs population integration, affects community and economic development, contributes to land use change, and structures service needs. Objective: Delineate historical net migration patterns by age, race/ethnic, and rural-urban dimensions for United States counties. Methods: Net migration rates by age for all US counties are aggregated from 1950−2010, summarized by rural-urban location and compared to explore differential race/ethnic patterns of age-specific net migration over time. Results: We identify distinct age-specific net migration 'signatures' that are consistent over time within county types, but different by rural-urban location and race/ethnic group. There is evidence of moderate population deconcentration and diminished racial segregation between 1990 and 2010. This includes a net outflow of Blacks from large urban core counties to suburban and smaller metropolitan counties, continued Hispanic deconcentration, and a slowdown in White counterurbanization. Conclusions: This paper contributes to a fuller understanding of the complex patterns of migration that have redistributed the U.S. population over the past six decades. It documents the variability in county age-specific net migration patterns both temporally and spatially, as well as the longitudinal consistency in migration signatures among county types and race/ethnic groups.

Determinants of use of insecticide-treated nets among pregnant women in Nigeria

Directory of Open Access Journals (Sweden)

Ezire O

2015-06-01

Full Text Available Onoriode Ezire,1 Samson B Adebayo,2 Omokhudu Idogho,3 Elijah A Bamgboye,4 Ernest Nwokolo5 1Research and Evaluation Division, Society for Family Health, Abuja, 2National Agency for Food and Drug Administration and Control, Abuja, 3Enhancing Nigeria’s Response to HIV & AIDS, Abuja, 4Medical Statistics, University of Ibadan, Ibadan, 5Society for Family Health, Abuja, Nigeria Background: Malaria in pregnancy is still a major health issue in Nigeria, accounting for about 33% of cause of maternal death. Despite massive efforts to make insecticide-treated net (ITN available to pregnant women in Nigeria, the use is still low. This study was conducted to identify facilitators and inhibitors for the use of ITN/long-lasting insecticidal net (LLIN among pregnant women in Nigeria.Methods: Data were obtained from the 2011 State-Specific HIV & AIDS, Reproductive and Child Health Survey conducted in 18 states of Nigeria. The survey was a population-based study among men and women of reproductive age living in households in rural and urban areas of Nigeria. Multistage cluster sampling technique was used to select eligible respondents. The sample size per state was 960 respondents. Data were collected between October and November 2011. The analysis was done using Statistical Package for Social Sciences (SPSS version 20.Results: A total of 11.5% of the respondents were pregnant at the time of the survey of which 73.2% lived in rural location and approximately 70% were either not educated or attained at most a primary school education. A total of 93.2% of respondents have heard of net, 82.6% were confident that they can hang or use a net, and 64.6% owned an ITN/LLIN in their household while the actual use was just 19.2%. We found education, location (urban–rural, confidence to use a net, and knowledge that the use of a net can protect a pregnant woman from malaria to be significant at 5% level. The number of nets owned per household, the length of time the net

Translating Colored Control Flow Nets into Readable Java via Annotated Java Workflow Nets

DEFF Research Database (Denmark)

Lassen, Kristian Bisgaard; Tjell, Simon

2007-01-01

In this paper, we present a method for developing Java applications from Colored Control Flow Nets (CCFNs), which is a special kind of Colored Petri Nets (CPNs) that we introduce. CCFN makes an explicit distinction between the representation of: The system, the environment of the system, and the ......In this paper, we present a method for developing Java applications from Colored Control Flow Nets (CCFNs), which is a special kind of Colored Petri Nets (CPNs) that we introduce. CCFN makes an explicit distinction between the representation of: The system, the environment of the system......, and the interface between the system and the environment. Our translation maps CCFNs into Anno- tated Java Workflow Nets (AJWNs) as an intermediate step, and these AJWNs are finally mapped to Java. CCFN is intended to enforce the modeler to describe the system in an imperative manner which makes the subsequent...... translation to Java easier to define. The translation to Java preserves data dependencies and control-flow aspects of the source CCFN. This paper contributes to the model-driven software development paradigm, by showing how to model a system, environment, and their interface, as a CCFN and presenting a fully...

Programming NET 35

CERN Document Server

Liberty, Jesse

2009-01-01

Bestselling author Jesse Liberty and industry expert Alex Horovitz uncover the common threads that unite the .NET 3.5 technologies, so you can benefit from the best practices and architectural patterns baked into the new Microsoft frameworks. The book offers a Grand Tour" of .NET 3.5 that describes how the principal technologies can be used together, with Ajax, to build modern n-tier and service-oriented applications. "

Net metering: zero electricity bill

International Nuclear Information System (INIS)

Mangi, A.; Khan, Z.

2011-01-01

Worldwide move towards renewable energy sources, environmental concerns and decentralization of the power sector have made net metering an attractive option for power generation at small scale. This paper discusses the net metering, economical issues of renewable sources in Pakistan, technical aspects, installation suitability according to varying terrain, existing utility rules and formulation of legislation for net metering making it economically attractive. (author)

Soil Respiration in Semiarid Temperate Grasslands under Various Land Management.

Directory of Open Access Journals (Sweden)

Zhen Wang

Full Text Available Soil respiration, a major component of the global carbon cycle, is significantly influenced by land management practices. Grasslands are potentially a major sink for carbon, but can also be a source. Here, we investigated the potential effect of land management (grazing, clipping, and ungrazed enclosures on soil respiration in the semiarid grassland of northern China. Our results showed the mean soil respiration was significantly higher under enclosures (2.17 μmol.m(-2.s(-1 and clipping (2.06 μmol.m(-2.s(-1 than under grazing (1.65 μmol.m-(2.s(-1 over the three growing seasons. The high rates of soil respiration under enclosure and clipping were associated with the higher belowground net primary productivity (BNPP. Our analyses indicated that soil respiration was primarily related to BNPP under grazing, to soil water content under clipping. Using structural equation models, we found that soil water content, aboveground net primary productivity (ANPP and BNPP regulated soil respiration, with soil water content as the predominant factor. Our findings highlight that management-induced changes in abiotic (soil temperature and soil water content and biotic (ANPP and BNPP factors regulate soil respiration in the semiarid temperate grassland of northern China.

Soil Respiration in Semiarid Temperate Grasslands under Various Land Management.

Science.gov (United States)

Wang, Zhen; Ji, Lei; Hou, Xiangyang; Schellenberg, Michael P

2016-01-01

Soil respiration, a major component of the global carbon cycle, is significantly influenced by land management practices. Grasslands are potentially a major sink for carbon, but can also be a source. Here, we investigated the potential effect of land management (grazing, clipping, and ungrazed enclosures) on soil respiration in the semiarid grassland of northern China. Our results showed the mean soil respiration was significantly higher under enclosures (2.17 μmol.m(-2).s(-1)) and clipping (2.06 μmol.m(-2).s(-1)) than under grazing (1.65 μmol.m-(2).s(-1)) over the three growing seasons. The high rates of soil respiration under enclosure and clipping were associated with the higher belowground net primary productivity (BNPP). Our analyses indicated that soil respiration was primarily related to BNPP under grazing, to soil water content under clipping. Using structural equation models, we found that soil water content, aboveground net primary productivity (ANPP) and BNPP regulated soil respiration, with soil water content as the predominant factor. Our findings highlight that management-induced changes in abiotic (soil temperature and soil water content) and biotic (ANPP and BNPP) factors regulate soil respiration in the semiarid temperate grassland of northern China.

Climatological Implications of Deep-Rooting in Water-Limited Ecosystems

Science.gov (United States)

Amenu, G. G.; Kumar, P.

2005-12-01

In vegetated ecosystems, plants are the primary channels that connect the soil with the atmosphere (through water, energy, carbon, and nutrient cycles), with plant roots controlling the below-ground dynamics. Recently, several observational evidences are emerging which suggests the existence of plant roots much deeper in the soil/rock profile than the depth usually perceived in existing hydroclimatological and hydroecological models. In this study, using land surface model, we assess the effects of vegetation deep-rooting on (a) moisture and temperature redistribution in the soil profile, (b) energy flux partitioning at the land surface, and (c) net primary productivity of vegetated ecosystems. Three sites characterized by different vegetation, soil, and climate (all located in arid to sub-humid regions of the United States) were studied. The sites include the Mogollon Rim in Arizona, the Edwards Plateau in Texas, and the Southern Piedmont in Georgia. Soil depths of up to 10 m are investigated. Results of this modeling effort and its implications for climatological modeling will be presented.

Net Locality

DEFF Research Database (Denmark)

de Souza e Silva, Adriana Araujo; Gordon, Eric

Provides an introduction to the new theory of Net Locality and the profound effect on individuals and societies when everything is located or locatable. Describes net locality as an emerging form of location awareness central to all aspects of digital media, from mobile phones, to Google Maps......, to location-based social networks and games, such as Foursquare and facebook. Warns of the threats these technologies, such as data surveillance, present to our sense of privacy, while also outlining the opportunities for pro-social developments. Provides a theory of the web in the context of the history...... of emerging technologies, from GeoCities to GPS, Wi-Fi, Wiki Me, and Google Android....

Net heterotrophy in small Danish lakes: A widespread feature over gradients in trophic status and land cover

DEFF Research Database (Denmark)

Sand-Jensen, Kaj; Stæhr, Peter Anton

2009-01-01

Nineteen small lakes located in open landscapes or deciduous forests in nutrient-rich calcareous moraines in North Zealand, Denmark, were all net heterotrophic having negative net ecosystem production and predominant CO2 supersaturation and O2 undersaturation of lake waters. Forest lakes were...... poorer in nutrients, phytoplankton, and primary production, but richer in dissolved organic matter and CO2 than open lakes with more light available. The modeled annual balance between gross primary production and community respiration (GPP/R COM) averaged 0.60 in forest lakes and 0.76 in open lakes...... and the ratio increased significantly with phosphorus concentration and phytoplankton biomass but decreased with colored dissolved organic matter. The negative daily rates of ecosystem production resembled estimates of oxygen uptake from the atmosphere to the lakes, whereas estimates of CO2 emission were 7...

Construction of monophase nets

International Nuclear Information System (INIS)

Suarez A, Jose Antonio

1996-01-01

The paper refers to the use of monophase loads in commercial residential urbanizations and in small industries, for this reason it is considered unnecessary the construction of three-phase nets. The author makes a historical recount of these nets in Bogota, his capacities, uses and energy savings

Land Use Effects on Net Greenhouse Gas Fluxes in the US Great Plains: Historical Trends and Model Projections

Science.gov (United States)

Del Grosso, S. J.; Parton, W. J.; Ojima, D. S.; Mosier, A. R.; Mosier, A. R.; Paustian, K.; Peterson, G. A.

2001-12-01

We present maps showing regional patterns of land use change and soil C levels in the US Great Plains during the 20th century and time series of net greenhouse gas fluxes associated with different land uses. Net greenhouse gas fluxes were calculated by accounting for soil CO2 fluxes, the CO2 equivalents of N2O emissions and CH4 uptake, and the CO2 costs of N fertilizer production. Both historical and modern agriculture in this region have been net sources of greenhouse gases. The primary reason for this, prior to 1950, is that agriculture mined soil C and resulted in net CO2 emissions. When chemical N fertilizer became widely used in the 1950's agricultural soils began to sequester CO2-C but these soils were still net greenhouse gas sources if the effects of increased N2O emissions and decreased CH4 uptake are included. The sensitivity of net greenhouse gas fluxes to conventional and alternative land uses was explored using the DAYCENT ecosystem model. Model projections suggest that conversion to no-till, reduction of the fallow period, and use of nitrification inhibitors can significantly decrease net greenhouse gas emissions in dryland and irrigated systems, while maintaining or increasing crop yields.

Caught in the Net: Perineuronal Nets and Addiction

Directory of Open Access Journals (Sweden)

Megan Slaker

2016-01-01

Full Text Available Exposure to drugs of abuse induces plasticity in the brain and creates persistent drug-related memories. These changes in plasticity and persistent drug memories are believed to produce aberrant motivation and reinforcement contributing to addiction. Most studies have explored the effect drugs of abuse have on pre- and postsynaptic cells and astrocytes; however, more recently, attention has shifted to explore the effect these drugs have on the extracellular matrix (ECM. Within the ECM are unique structures arranged in a net-like manner, surrounding a subset of neurons called perineuronal nets (PNNs. This review focuses on drug-induced changes in PNNs, the molecules that regulate PNNs, and the expression of PNNs within brain circuitry mediating motivation, reward, and reinforcement as it pertains to addiction.

Identifying Telemedicine Services to Improve Access to Specialty Care for the Underserved in the San Francisco Safety Net

Directory of Open Access Journals (Sweden)

Ken Russell Coelho

2011-01-01

Full Text Available Safety-net settings across the country have grappled with providing adequate access to specialty care services. San Francisco General Hospital and Trauma Center, serving as the city's primary safety-net hospital, has also had to struggle with the same issue. With Healthy San Francisco, the City and County of San Francisco's Universal Healthcare mandate, the increased demand for specialty care services has placed a further strain on the system. With the recent passage of California Proposition 1D, infrastructural funds are now set aside to assist in connecting major hospitals with primary care clinics in remote areas all over the state of California, using telemedicine. Based on a selected sample of key informant interviews with local staff physicians, this study provides further insight into the current process of e-referral which uses electronic communication for making referrals to specialty care. It also identifies key services for telemedicine in primary and specialty care settings within the San Francisco public health system. This study concludes with proposals for a framework that seek to increase collaboration between the referring primary care physician and specialist, to prioritize institution of these key services for telemedicine.

Below-ground biomass production and allometric relationships of eucalyptus coppice plantation in the central highlands of Madagascar

International Nuclear Information System (INIS)

Razakamanarivo, Ramarson H.; Razakavololona, Ando; Razafindrakoto, Marie-Antoinette; Vieilledent, Ghislain; Albrecht, Alain

2012-01-01

Short rotations of Eucalyptus plantations under coppice regime are extensively managed for wood production in Madagascar. Nevertheless, little is known about their biomass production and partitioning and their potential in terms of carbon sequestration. If above-ground biomass (AGB) can be estimated based on established allometric relations, below-ground (BGB) estimates are much less common. The aim of this work was to develop allometric equations to estimate biomass of these plantations, mainly for the root components. Data from 9 Eucalyptus robusta stands (47–87 years of plantation age, 3–5 years of coppice-shoot age) were collected and analyzed. Biomass of 3 sampled trees per stand was determined destructively. Dry weight of AGB components (leaves, branches and stems) were estimated as a function of basal area of all shoots per stump and dry weight for BGB components (mainly stump, coarse root (CR) and medium root (MR)) were estimated as a function of stump circumference. Biomass was then computed using allometric equations from stand inventory data. Stand biomass ranged from 102 to 130 Mg ha −1 with more than 77% contained in the BGB components. The highest dry weight was allocated in the stump and in the CR (51% and 42% respectively) for BGB parts and in the stem (69%) for AGB part. Allometric relationships developed herein could be applied to other Eucalyptus plantations which present similar stand density and growing conditions; anyhow, more is needed to be investigated in understanding biomass production and partitioning over time for this kind of forest ecosystem. -- Highlights: ► We studied the potential of old eucalyptus coppices in Madagascar to mitigate global warming. ► Biomass measurement, mainly for below-ground BGB (stump, coarse-medium-and fine roots) was provided. ► BGB allometry relationships for short rotation forestry under coppice were established. ► BGB were found to be important with their 102-130MgC ha -1 (<77% of the C in

Additive Manufacturing of Near-net Shaped Permanent Magnets

Energy Technology Data Exchange (ETDEWEB)

Paranthaman, M Parans [ORNL

2016-07-26

The technical objective of this technical collaboration phase I proposal is to fabricate near net-shaped permanent magnets using alloy powders utilizing direct metal deposition technologies at the ORNL MDF. Direct Manufacturing using the POM laser system was used to consolidate Nd₂Fe₁₄B (NdFeB) magnet powders into near net-shape parts efficiently and with virtually no wasted material as part of the feasibility study. We fabricated builds based on spherical NdFeB magnet particles. The results show that despite the ability to fabricate highly reactive materials in the laser deposition process, the magnetic coercivity and remanence of the NdFeB hard magnets is significantly reduced. X-ray powder diffraction in conjunction with electron microscopy showed that the material experienced a primary Nd₂Fe₁₇B_x solidification due to the undercooling effect (>60K). Consequently the presence of alpha iron phase resulted in deterioration of the build properties. Further optimization of the processing parameters is needed to maintain the Nd₂Fe₁₄B phase during fabrication.

The K-NET - A year after

International Nuclear Information System (INIS)

Kinoshita, S.; Ohtani, K.; Katayama, T.

2001-01-01

We started to release the K-NET strong-motion data from June 1996 and about one year passed. In this article, we report the development of K-NET and some applications using the K-NET information released on the Internet. (author)

Mars MetNet Mission Status

Science.gov (United States)

Harri, A.-M.; Aleksashkin, S.; Arruego, I.; Schmidt, W.; Genzer, M.; Vazquez, L.; Haukka, H.; Palin, M.; Nikkanen, T.

2015-10-01

New kind of planetary exploration mission for Mars is under development in collaboration between the Finnish Meteorological Institute (FMI), Lavochkin Association (LA), Space Research Institute (IKI) and Institutio Nacional de Tecnica Aerospacial (INTA). The Mars MetNet mission is based on a new semihard landing vehicle called MetNet Lander (MNL). The scientific payload of the Mars MetNet Precursor [1] mission is divided into three categories: Atmospheric instruments, Optical devices and Composition and structure devices. Each of the payload instruments will provide significant insights in to the Martian atmospheric behavior. The key technologies of the MetNet Lander have been qualified and the electrical qualification model (EQM) of the payload bay has been built and successfully tested.

Sub-canopy light conditions only allow low annual net productivity of epiphytic algae on kelp Laminaria hyperborea

DEFF Research Database (Denmark)

Pedersen, Morten Foldager; Nejrup, Lars Brammer; Pedersen, Troels Møller

2014-01-01

The stipes of older Laminaria hyperborea individuals are heavily covered by epiphytic assemblages that are dominated by macroalgae, and we hypothesized that the production of these algae may contribute significantly to total primary production of the kelp forest ecosystem. The epiphytic assemblages...... through spring as surface irradiance increased. Annual net productivity was relatively low, ranging from 42 to 96 g DW m-2 seafloor depending on site. We conclude that the net productivity of these macroalgal epiphytes is insignificant relative to that of kelp itself, and that the large observed biomass...

NET SALARY ADJUSTMENT

CERN Multimedia

Finance Division

2001-01-01

On 15 June 2001 the Council approved the correction of the discrepancy identified in the net salary adjustment implemented on 1st January 2001 by retroactively increasing the scale of basic salaries to achieve the 2.8% average net salary adjustment approved in December 2000. We should like to inform you that the corresponding adjustment will be made to your July salary. Full details of the retroactive adjustments will consequently be shown on your pay slip.

Changes of net primary productivity in China during recent 11 years detected using an ecological model driven by MODIS data

Science.gov (United States)

Liu, Yibo; Ju, Weimin; He, Honglin; Wang, Shaoqiang; Sun, Rui; Zhang, Yuandong

2013-03-01

Net primary productivity (NPP) is an important component of the terrestrial carbon cycle. Accurately mapping the spatial-temporal variations of NPP in China is crucial for global carbon cycling study. In this study the process-based Boreal Ecosystem Productivity Simulator (BEPS) was employed to study the changes of NPP in China's ecosystems for the period from 2000 to 2010. The BEPS model was first validated using gross primary productivity (GPP) measured at typical flux sites and forest NPP measured at different regions. Then it was driven with leaf area index (LAI) inversed from the Moderate Resolution Imaging Spectroradiometer (MODIS) reflectance and land cover products and meteorological data interpolated from observations at 753 national basic meteorological stations to simulate NPP at daily time steps and a spatial resolution of 500 m from January 1, 2000 to December 31, 2010. Validations show that BEPS is able to capture the seasonal variations of tower-based GPP and the spatial variability of forest NPP in different regions of China. Estimated national total of annual NPP varied from 2.63 to 2.84Pg C·yr-1, averaging 2.74 Pg C·yr-1 during the study period. Simulated terrestrial NPP shows spatial patterns decreasing from the east to the west and from the south to the north, in association with land cover types and climate. South-west China makes the largest contribution to the national total of NPP while NPP in the North-west account for only 3.97% of the national total. During the recent 11 years, the temporal changes of NPP were heterogamous. NPP increased in 63.8% of China's landmass, mainly in areas north of the Yangtze River and decreased in most areas of southern China, owing to the low temperature freezing in early 2008 and the severe drought in late 2009.

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

Net energy gain from DT fusion

International Nuclear Information System (INIS)

Buende, R.

1985-01-01

The net energy which can be gained from an energy raw material by means of a certain conversion system is deduced as the figure-of-merit which adequately characterizes the net energy balance of utilizing an energy source. This potential net energy gain is determined for DT fusion power plants. It is represented as a function of the degree of exploitation of the energy raw material lithium ore and is compared with the net energy which can be gained with LW and FBR power plants by exploiting uranium ore. The comparison clearly demonstrates the net energetic advantage of DT fusion. A sensitivity study shows that this holds even if the energy expenditure for constructing and operating is drastically increased

Nitrogen soil emissions and belowground plant processes in Mediterranean annual pastures are altered by ozone exposure and N-inputs

Science.gov (United States)

Sánchez-Martín, L.; Bermejo-Bermejo, V.; García-Torres, L.; Alonso, R.; de la Cruz, A.; Calvete-Sogo, H.; Vallejo, A.

2017-09-01

Increasing tropospheric ozone (O3) and atmospheric nitrogen (N) deposition alter the structure and composition of pastures. These changes could affect N and C compounds in the soil that in turn can influence soil microbial activity and processes involved in the emission of N oxides, methane (CH4) and carbon dioxide (CO2), but these effects have been scarcely studied. Through an open top chamber (OTC) field experiment, the combined effects of both pollutants on soil gas emissions from an annual experimental Mediterranean community were assessed. Four O3 treatments and three different N input levels were considered. Fluxes of nitric (NO) and nitrous (N2O) oxide, CH4 and CO2 were analysed as well as soil mineral N and dissolved organic carbon. Belowground plant parameters like root biomass and root C and N content were also sampled. Ozone strongly increased soil N2O emissions, doubling the cumulative emission through the growing cycle in the highest O3 treatment, while N-inputs enhanced more slightly NO; CH4 and CO2 where not affected. Both N-gases had a clear seasonality, peaking at the start and at the end of the season when pasture physiological activity is minimal; thus, higher microorganism activity occurred when pasture had a low nutrient demand. The O3-induced peak of N2O under low N availability at the end of the growing season was counterbalanced by the high N inputs. These effects were related to the O3 x N significant interaction found for the root-N content in the grass and the enhanced senescence of the community. Results indicate the importance of the belowground processes, where competition between plants and microorganisms for the available soil N is a key factor, for understanding the ecosystem responses to O3 and N.

Net alkalinity and net acidity 2: Practical considerations

Science.gov (United States)

Kirby, C.S.; Cravotta, C.A.

2005-01-01

The pH, alkalinity, and acidity of mine drainage and associated waters can be misinterpreted because of the chemical instability of samples and possible misunderstandings of standard analytical method results. Synthetic and field samples of mine drainage having various initial pH values and concentrations of dissolved metals and alkalinity were titrated by several methods, and the results were compared to alkalinity and acidity calculated based on dissolved solutes. The pH, alkalinity, and acidity were compared between fresh, unoxidized and aged, oxidized samples. Data for Pennsylvania coal mine drainage indicates that the pH of fresh samples was predominantly acidic (pH 2.5-4) or near neutral (pH 6-7); ??? 25% of the samples had pH values between 5 and 6. Following oxidation, no samples had pH values between 5 and 6. The Standard Method Alkalinity titration is constrained to yield values >0. Most calculated and measured alkalinities for samples with positive alkalinities were in close agreement. However, for low-pH samples, the calculated alkalinity can be negative due to negative contributions by dissolved metals that may oxidize and hydrolyze. The Standard Method hot peroxide treatment titration for acidity determination (Hot Acidity) accurately indicates the potential for pH to decrease to acidic values after complete degassing of CO2 and oxidation of Fe and Mn, and it indicates either the excess alkalinity or that required for neutralization of the sample. The Hot Acidity directly measures net acidity (= -net alkalinity). Samples that had near-neutral pH after oxidation had negative Hot Acidity; samples that had pH mine drainage treatment can lead to systems with insufficient Alkalinity to neutralize metal and H+ acidity and is not recommended. The use of net alkalinity = -Hot Acidity titration is recommended for the planning of mine drainage treatment. The use of net alkalinity = (Alkalinitymeasured - Aciditycalculated) is recommended with some cautions

Bed net ownership in Kenya: the impact of 3.4 million free bed nets

Directory of Open Access Journals (Sweden)

Vulule John

2010-06-01

Full Text Available Abstract Background In July and September 2006, 3.4 million long-lasting insecticide-treated bed nets (LLINs were distributed free in a campaign targeting children 0-59 months old (CU5s in the 46 districts with malaria in Kenya. A survey was conducted one month after the distribution to evaluate who received campaign LLINs, who owned insecticide-treated bed nets and other bed nets received through other channels, and how these nets were being used. The feasibility of a distribution strategy aimed at a high-risk target group to meet bed net ownership and usage targets is evaluated. Methods A stratified, two-stage cluster survey sampled districts and enumeration areas with probability proportional to size. Handheld computers (PDAs with attached global positioning systems (GPS were used to develop the sampling frame, guide interviewers back to chosen households, and collect survey data. Results In targeted areas, 67.5% (95% CI: 64.6, 70.3% of all households with CU5s received campaign LLINs. Including previously owned nets, 74.4% (95% CI: 71.8, 77.0% of all households with CU5s had an ITN. Over half of CU5s (51.7%, 95% CI: 48.8, 54.7% slept under an ITN during the previous evening. Nearly forty percent (39.1% of all households received a campaign net, elevating overall household ownership of ITNs to 50.7% (95% CI: 48.4, 52.9%. Conclusions The campaign was successful in reaching the target population, families with CU5s, the risk group most vulnerable to malaria. Targeted distribution strategies will help Kenya approach indicator targets, but will need to be combined with other strategies to achieve desired population coverage levels.

Quantitative assessment of human-induced impacts based on net primary productivity in Guangzhou, China.

Science.gov (United States)

Wu, Yanyan; Wu, Zhifeng

2018-02-08

Urban expansion and land cover change driven primarily by human activities have significant influences on the urban eco-environment, and together with climate change jointly alter net primary productivity (NPP). However, at the spatiotemporal scale, there has been limited quantitative analysis of the impacts of human activities independent of climate change on NPP. We chose Guangzhou city as a study area to analyze the impacts of human activities on NPP, as well as the spatiotemporal variations of those impacts within three segments, using a relative impact index (RII) based on potential NPP (NPP p ), actual NPP (NPP act ), and NPP appropriation due to land use/land cover change (NPP lulc ). The spatial patterns and dynamics of NPP act and NPP lulc were evaluated and the impacts of human activities on NPP during the process of urban sprawl were quantitatively analyzed and assessed using the RII. The results showed that NPP act and NPP lulc in the study area had clear spatial heterogeneity, between 2001 and 2013 there was a declining trend in NPP act while an increasing trend occurred in NPP lulc , and those trends were especially significant in the 10-40-km segment. The results also revealed that more than 91.0% of pixels in whole study region had positive RII values, while the lowest average RII values were found in the > 40-km segment (39.03%), indicating that human activities were not the main cause for the change in NPP there; meanwhile, the average RII was greater than 65.0% in the other two, suggesting that they were subjected to severe anthropogenic disturbances. The RII values in all three segments of the study area increased, indicating an increasing human interference. The 10-40-km buffer zone had the largest slope value (0.5665), suggesting that this segment was closely associated with growing human disturbances. Particularly noteworthy is the fact that the > 40-km segment had a large slope value (0.3323) and required more conservation efforts. Based

Effects of vegetation heterogeneity and surface topography on spatial scaling of net primary productivity

Science.gov (United States)

Chen, J. M.; Chen, X.; Ju, W.

2013-07-01

Due to the heterogeneous nature of the land surface, spatial scaling is an inevitable issue in the development of land models coupled with low-resolution Earth system models (ESMs) for predicting land-atmosphere interactions and carbon-climate feedbacks. In this study, a simple spatial scaling algorithm is developed to correct errors in net primary productivity (NPP) estimates made at a coarse spatial resolution based on sub-pixel information of vegetation heterogeneity and surface topography. An eco-hydrological model BEPS-TerrainLab, which considers both vegetation and topographical effects on the vertical and lateral water flows and the carbon cycle, is used to simulate NPP at 30 m and 1 km resolutions for a 5700 km2 watershed with an elevation range from 518 m to 3767 m in the Qinling Mountain, Shanxi Province, China. Assuming that the NPP simulated at 30 m resolution represents the reality and that at 1 km resolution is subject to errors due to sub-pixel heterogeneity, a spatial scaling index (SSI) is developed to correct the coarse resolution NPP values pixel by pixel. The agreement between the NPP values at these two resolutions is improved considerably from R2 = 0.782 to R2 = 0.884 after the correction. The mean bias error (MBE) in NPP modelled at the 1 km resolution is reduced from 14.8 g C m-2 yr-1 to 4.8 g C m-2 yr-1 in comparison with NPP modelled at 30 m resolution, where the mean NPP is 668 g C m-2 yr-1. The range of spatial variations of NPP at 30 m resolution is larger than that at 1 km resolution. Land cover fraction is the most important vegetation factor to be considered in NPP spatial scaling, and slope is the most important topographical factor for NPP spatial scaling especially in mountainous areas, because of its influence on the lateral water redistribution, affecting water table, soil moisture and plant growth. Other factors including leaf area index (LAI) and elevation have small and additive effects on improving the spatial scaling

Effects of vegetation heterogeneity and surface topography on spatial scaling of net primary productivity

Directory of Open Access Journals (Sweden)

J. M. Chen

2013-07-01

Full Text Available Due to the heterogeneous nature of the land surface, spatial scaling is an inevitable issue in the development of land models coupled with low-resolution Earth system models (ESMs for predicting land-atmosphere interactions and carbon-climate feedbacks. In this study, a simple spatial scaling algorithm is developed to correct errors in net primary productivity (NPP estimates made at a coarse spatial resolution based on sub-pixel information of vegetation heterogeneity and surface topography. An eco-hydrological model BEPS-TerrainLab, which considers both vegetation and topographical effects on the vertical and lateral water flows and the carbon cycle, is used to simulate NPP at 30 m and 1 km resolutions for a 5700 km2 watershed with an elevation range from 518 m to 3767 m in the Qinling Mountain, Shanxi Province, China. Assuming that the NPP simulated at 30 m resolution represents the reality and that at 1 km resolution is subject to errors due to sub-pixel heterogeneity, a spatial scaling index (SSI is developed to correct the coarse resolution NPP values pixel by pixel. The agreement between the NPP values at these two resolutions is improved considerably from R2 = 0.782 to R2 = 0.884 after the correction. The mean bias error (MBE in NPP modelled at the 1 km resolution is reduced from 14.8 g C m−2 yr−1 to 4.8 g C m−2 yr−1 in comparison with NPP modelled at 30 m resolution, where the mean NPP is 668 g C m−2 yr−1. The range of spatial variations of NPP at 30 m resolution is larger than that at 1 km resolution. Land cover fraction is the most important vegetation factor to be considered in NPP spatial scaling, and slope is the most important topographical factor for NPP spatial scaling especially in mountainous areas, because of its influence on the lateral water redistribution, affecting water table, soil moisture and plant growth. Other factors including leaf area index (LAI and elevation have small and additive effects on improving

47 CFR 65.450 - Net income.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Net income. 65.450 Section 65.450... OF RETURN PRESCRIPTION PROCEDURES AND METHODOLOGIES Exchange Carriers § 65.450 Net income. (a) Net income shall consist of all revenues derived from the provision of interstate telecommunications services...

Business Profile of Boat Lift Net and Stationary Lift Net Fishing Gear in Morodemak Waters Central Java

Science.gov (United States)

Hapsari, Trisnani D.; Jayanto, Bogi B.; Fitri, Aristi D. P.; Triarso, I.

2018-02-01

Lift net is one of the fishing gears that is used widely in the Morodemak coastal fishing port (PPP) for catching pelagic fish. The yield of fish captured by these fishing gear has high economic value, such as fish belt (Trichiurus sp), squids (Loligo sp) and anchovies (Stelophorus sp). The aims of this research were to determine the technical aspects of boat lift net and stationary lift net fishing gear in Morodemak Waters Demak Regency; to find out the financial aspect of those fishing gears and to analyze the financial feasibility by counting PP, NPV, IRR, and B/C ratio criteria. This research used case study method with descriptive analysis. The sampling method was purposive sampling with 22 fishermen as respondents. The result of the research showed that the average of boat lift net acceptance was Rp 388,580,000. The financial analysis of fisheries boat lift net with the result of NPV Rp 836,149,272, PP 2.44 years, IRR value 54%, and B/C ratio 1.73. The average of stationary lift net acceptance was Rp 27,750,000. The financial analysis lift net with the result of NPV Rp 37,937,601; PP 1.96 years, IRR value 86%, and B/C ratio 1.32. This research had a positive NPV value, B/C ratio >1, and IRR > discount rate (12 %). This study concluded that the fishery business of boat lift net and stationary lift net in Morodemak coastal fishing port (PPP) was worth running.

Net neutrality and audiovisual services

OpenAIRE

van Eijk, N.; Nikoltchev, S.

2011-01-01

Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication networks: the control over the distribution of audiovisual services constitutes a vital part of the problem. In this contribution, the phenomenon of net neutrality is described first. Next, the European a...

47 CFR 65.500 - Net income.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Net income. 65.500 Section 65.500... OF RETURN PRESCRIPTION PROCEDURES AND METHODOLOGIES Interexchange Carriers § 65.500 Net income. The net income methodology specified in § 65.450 shall be utilized by all interexchange carriers that are...

Aplicació Microsoft .Net : Hotel Spa

OpenAIRE

Marquès Palmer, Jordi

2010-01-01

Desenvolupament d'una aplicació amb Microsoft .NET, WCF, WPF, Linq2SQL, d'un Hotel Spa. Desarrollo de una aplicación con Microsoft .NET, WCF, WPF, Linq2SQL, de un Hotel Spa. Application development using Microsoft .NET, WCF, WPF, Linq2SQL, for a Spa Hotel.

Tracing trade-related telecouplings in the global land-system using the embodied human appropriation of net primary production framework

Science.gov (United States)

Haberl, H.; Kastner, T.; Schaffartzik, A.; Erb, K. H.

2015-12-01

Global land-system change is influenced by a complex set of drivers that transcend spatial, institutional and temporal scales. The notion of "telecouplings" is gaining importance in Land System Science as a framework to address that complexity of drivers. One of them is the trade in land-based products, which forges connections between different geographic regions. Trade in land-based products is growing rapidly, thereby creating an increasing spatial disconnect between the locations where primary products (e.g. crops, fodder or timber) are grown and harvested and where the related environmental pressures occur, and the locations where final products (e.g. food, fiber or bioenergy) are consumed. Governing land-related sustainability issues such as GHG emissions or pressures on biodiversity and ecosystems related with land-use changes requires information on trade-related telecouplings, e.g. in order to avoid leakage effects. However, tracing land use (change) related with flows of traded products is challenging, among others due to (a) the lack of easily implementable metrics to account for differences in land quality and land-use intensity, and (b) the lack of satisfactory methods to allocate land to products that are traded and consumed. Drawing from a database derived from FAO statistics that allows tracing bilateral trade flows between ~200 countries at a resolution of ~500 products for the time period 1986-2006, this presentation will discuss how the framework of embodied human appropriation of net primary production (eHANPP) can help tackling these difficult issues. The HANPP framework allows to consistently represent important aspects of land quality and land-use intensity, e.g. natural productivity potential or land-use efficiency. In terms of allocation of land to products, eHANPP is a factor-based approach, and the presentation will discuss differences to alternative methods such as environmentally extended input-output analysis. We will use the available

Automatic Prompt System in the Process of Mapping plWordNet on Princeton WordNet

Directory of Open Access Journals (Sweden)

Paweł Kędzia

2015-06-01

Full Text Available Automatic Prompt System in the Process of Mapping plWordNet on Princeton WordNet The paper offers a critical evaluation of the power and usefulness of an automatic prompt system based on the extended Relaxation Labelling algorithm in the process of (manual mapping plWordNet on Princeton WordNet. To this end the results of manual mapping – that is inter-lingual relations between plWN and PWN synsets – are juxtaposed with the automatic prompts that were generated for the source language synsets to be mapped. We check the number and type of inter-lingual relations introduced on the basis of automatic prompts and the distance of the respective prompt synsets from the actual target language synsets.

Forest biomass, productivity and carbon cycling along a rainfall gradient in West Africa.

Science.gov (United States)

Moore, Sam; Adu-Bredu, Stephen; Duah-Gyamfi, Akwasi; Addo-Danso, Shalom D; Ibrahim, Forzia; Mbou, Armel T; de Grandcourt, Agnès; Valentini, Riccardo; Nicolini, Giacomo; Djagbletey, Gloria; Owusu-Afriyie, Kennedy; Gvozdevaite, Agne; Oliveras, Imma; Ruiz-Jaen, Maria C; Malhi, Yadvinder

2018-02-01

Net Primary Productivity (NPP) is one of the most important parameters in describing the functioning of any ecosystem and yet it arguably remains a poorly quantified and understood component of carbon cycling in tropical forests, especially outside of the Americas. We provide the first comprehensive analysis of NPP and its carbon allocation to woody, canopy and root growth components at contrasting lowland West African forests spanning a rainfall gradient. Using a standardized methodology to study evergreen (EF), semi-deciduous (SDF), dry forests (DF) and woody savanna (WS), we find that (i) climate is more closely related with above and belowground C stocks than with NPP (ii) total NPP is highest in the SDF site, then the EF followed by the DF and WS and that (iii) different forest types have distinct carbon allocation patterns whereby SDF allocate in excess of 50% to canopy production and the DF and WS sites allocate 40%-50% to woody production. Furthermore, we find that (iv) compared with canopy and root growth rates the woody growth rate of these forests is a poor proxy for their overall productivity and that (v) residence time is the primary driver in the productivity-allocation-turnover chain for the observed spatial differences in woody, leaf and root biomass across the rainfall gradient. Through a systematic assessment of forest productivity we demonstrate the importance of directly measuring the main components of above and belowground NPP and encourage the establishment of more permanent carbon intensive monitoring plots across the tropics. © 2017 John Wiley & Sons Ltd.

Loss of protection with insecticide-treated nets against pyrethroid-resistant Culex quinquefasciatus mosquitoes once nets become holed: an experimental hut study

Directory of Open Access Journals (Sweden)

Irish SR

2008-06-01

Full Text Available Abstract Background An important advantage of pyrethroid-treated nets over untreated nets is that once nets become worn or holed a pyrethroid treatment will normally restore protection. The capacity of pyrethroids to kill or irritate any mosquito that comes into contact with the net and prevent penetration of holes or feeding through the sides are the main reasons why treated nets continue to provide protection despite their condition deteriorating over time. Pyrethroid resistance is a growing problem among Anopheline and Culicine mosquitoes in many parts of Africa. When mosquitoes become resistant the capacity of treated nets to provide protection might be diminished, particularly when holed. An experimental hut trial against pyrethroid-resistant Culex quinquefasciatus was therefore undertaken in southern Benin using a series of intact and holed nets, both untreated and treated, to assess any loss of protection as nets deteriorate with use and time. Results There was loss of protection when untreated nets became holed; the proportion of mosquitoes blood feeding increased from 36.2% when nets were intact to between 59.7% and 68.5% when nets were holed to differing extents. The proportion of mosquitoes blood feeding when treated nets were intact was 29.4% which increased to 43.6–57.4% when nets were holed. The greater the number of holes the greater the loss of protection regardless of whether nets were untreated or treated. Mosquito mortality in huts with untreated nets was 12.9–13.6%; treatment induced mortality was less than 12%. The exiting rate of mosquitoes into the verandas was higher in huts with intact nets. Conclusion As nets deteriorate with use and become increasingly holed the capacity of pyrethroid treatments to restore protection is greatly diminished against resistant Culex quinquefasciatus mosquitoes.

Traditional nets interfere with the uptake of long-lasting insecticidal nets in the Peruvian Amazon: the relevance of net preference for achieving high coverage and use.

Directory of Open Access Journals (Sweden)

Koen Peeters Grietens

Full Text Available While coverage of long-lasting insecticide-treated nets (LLIN has steadily increased, a growing number of studies report gaps between net ownership and use. We conducted a mixed-methods social science study assessing the importance of net preference and use after Olyset® LLINs were distributed through a mass campaign in rural communities surrounding Iquitos, the capital city of the Amazonian region of Peru.The study was conducted in the catchment area of the Paujil and Cahuide Health Centres (San Juan district between July 2007 and November 2008. During a first qualitative phase, participant observation and in-depth interviews collected information on key determinants for net preference and use. In a second quantitative phase, a survey among recently confirmed malaria patients evaluated the acceptability and use of both LLINs and traditional nets, and a case control study assessed the association between net preference/use and housing structure (open vs. closed houses.A total of 10 communities were selected for the anthropological fieldwork and 228 households participated in the quantitative studies. In the study area, bed nets are considered part of the housing structure and are therefore required to fulfil specific architectural and social functions, such as providing privacy and shelter, which the newly distributed Olyset® LLINs ultimately did not. The LLINs' failure to meet these criteria could mainly be attributed to their large mesh size, transparency and perceived ineffectiveness to protect against mosquitoes and other insects, resulting in 63.3% of households not using any of the distributed LLINs. Notably, LLIN usage was significantly lower in houses with no interior or exterior walls (35.2% than in those with walls (73.8% (OR = 5.2, 95CI [2.2; 12.3], p<0.001.Net preference can interfere with optimal LLIN use. In order to improve the number of effective days of LLIN protection per dollar spent, appropriate quantitative and qualitative

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

Science.gov (United States)

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

2015-06-01

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

Delta Semantics Defined By Petri Nets

DEFF Research Database (Denmark)

Jensen, Kurt; Kyng, Morten; Madsen, Ole Lehrmann

and the possibility of using predicates to specify state changes. In this paper a formal semantics for Delta is defined and analysed using Petri nets. Petri nets was chosen because the ideas behind Petri nets and Delta concide on several points. A number of proposals for changes in Delta, which resulted from...

Coloured Petri Nets and the Invariant Method

DEFF Research Database (Denmark)

Jensen, Kurt

1981-01-01

processes to be described by a common subnet, without losing the ability to distinguish between them. Our generalization, called coloured Petri nets, is heavily influenced by predicate transition-nets introduced by H.J. Genrich and K. Lautenbach. Moreover our paper shows how the invariant-method, introduced...... for Petri nets by K. Lautenbach, can be generalized to coloured Petri nets....

Net metering in British Columbia : white paper

International Nuclear Information System (INIS)

Berry, T.

2003-01-01

Net metering was described as being the reverse registration of an electricity customer's revenue meter when interconnected with a utility's grid. It is a provincial policy designed to encourage small-distributed renewable power generation such as micro-hydro, solar energy, fuel cells, and larger-scale wind energy. It was noted that interconnection standards for small generation is an important issue that must be addressed. The British Columbia Utilities Commission has asked BC Hydro to prepare a report on the merits of net metering in order to support consultations on a potential net metering tariff application by the utility. This report provides information on net metering with reference to experience in other jurisdictions with net metering, and the possible costs and benefits associated with net metering from both a utility and consumer perspective. Some of the barriers and policy considerations for successful implementation of net metering were also discussed. refs., tabs., figs

Variation and Trends of Landscape Dynamics, Land Surface Phenology and Net Primary Production of the Appalachian Mountains

Energy Technology Data Exchange (ETDEWEB)

Wang, Yeqiao; Zhao, Jianjun; Zhou, Yuyu; Zhang, Hongyan

2012-12-15

The gradients of the Appalachian Mountains in elevations and latitudes provide a unique regional perspective of landscape variations in the eastern United States and a section of the southeastern Canada. This study reveals patterns and trends of landscape dynamics, land surface phenology and ecosystem production along the Appalachian Mountains using time series data from Global Inventory Modeling and Mapping Studies (GIMMS) and AVHRR Global Production Efficiency Model (GloPEM) datasets. We analyzed the spatial and temporal patterns of Normalized Difference Vegetation Index (NDVI), length of growing season (LOS) and net primary production (NPP) of selected ecoregions along the Appalachian Mountains regions. We compared the results out of the Appalachian Mountains regions in different spatial contexts including the North America and the Appalachian Trail corridor area. To reveal latitudinal variations we analyzed data and compared the results between 30°N-40°N and 40°N-50°N latitudes. The result revealed significant decreases in annual peak NDVI in the Appalachian Mountains regions. The trend for the Appalachian Mountains regions was -0.0018 (R2=0.55, P<0.0001) NDVI unit decrease per year during 25 years between 1982 and 2006. The LOS had prolonged 0.3 day yr-1 during 25 years over the Appalachian Mountains regions. The NPP increased by 2.68 gC m-2yr-2 in Appalachian Mountains regions from 1981 to 2000. The comparison with the North America reveals the effects of topography and ecosystem compositions of the Appalachian Mountains. The comparison with the Appalachian Trail corridor area provides a regional mega-transect view of the measured variables.

Upper Primary Students Constructing and Exploring Three Dimensional Shapes: A Comparison of Virtual Reality with Card Nets.

Science.gov (United States)

Ainge, David J.

1996-01-01

A grade 6/7 class which constructed and explored three-dimensional shapes with the VREAM virtual reality (VR) development system program was compared with a grade 5/6/7 control group using card nets (diagrams which can be cut out/folded). Results indicated that VR had little impact on shape visualization and name writing, but it strongly enhanced…

Mom-net: Evaluation of an internet-facilitated cognitive behavioral intervention for low-income depressed mothers.

Science.gov (United States)

Sheeber, Lisa B; Feil, Edward G; Seeley, John R; Leve, Craig; Gau, Jeff M; Davis, Betsy; Sorensen, Erik; Allan, Steve

2017-04-01

Evaluate an Internet-facilitated cognitive-behavioral treatment intervention for depression, tailored to economically disadvantaged mothers of young children. Economically disadvantaged mothers (N = 266) of preschool aged children, who reported elevated levels of depressive symptoms, were randomized to either the 8-session, Internet-facilitated intervention (Mom-Net) or to Motivational Interviewing and Referral to Services (MIRS). Outcomes were measured using the Patient Health Questionnaire 9 (PHQ-9; Spitzer et al., 1999), the Structured Clinical Interview for Diagnostic and Statistical Manual for Mental Disorders-Fourth Edition-Text Revised (DSM-IV-TR) Axis I Disorders (SCID; First, Spitzer, Gibbon, & Williams, 2002), and the Hamilton Depression Rating Scale (HDRS; Hamilton, 1960). Relative to participants in the MIRS condition, participants in Mom-Net demonstrated significantly greater reduction in depression as indexed by self-report questionnaire (primary outcome), interviewer-rated symptoms, and diagnostic outcomes. Results suggest that the Mom-Net intervention is effective as a remotely delivered intervention for economically disadvantaged mothers. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Biological Petri Nets

CERN Document Server

Wingender, E

2011-01-01

It was suggested some years ago that Petri nets might be well suited to modeling metabolic networks, overcoming some of the limitations encountered by the use of systems employing ODEs (ordinary differential equations). Much work has been done since then which confirms this and demonstrates the usefulness of this concept for systems biology. Petri net technology is not only intuitively understood by scientists trained in the life sciences, it also has a robust mathematical foundation and provides the required degree of flexibility. As a result it appears to be a very promising approach to mode

Modelling of current loads on aquaculture net cages

Science.gov (United States)

Kristiansen, Trygve; Faltinsen, Odd M.

2012-10-01

In this paper we propose and discuss a screen type of force model for the viscous hydrodynamic load on nets. The screen model assumes that the net is divided into a number of flat net panels, or screens. It may thus be applied to any kind of net geometry. In this paper we focus on circular net cages for fish farms. The net structure itself is modelled by an existing truss model. The net shape is solved for in a time-stepping procedure that involves solving a linear system of equations for the unknown tensions at each time step. We present comparisons to experiments with circular net cages in steady current, and discuss the sensitivity of the numerical results to a set of chosen parameters. Satisfactory agreement between experimental and numerical prediction of drag and lift as function of the solidity ratio of the net and the current velocity is documented.

PhysioNet

Data.gov (United States)

U.S. Department of Health & Human Services — The PhysioNet Resource is intended to stimulate current research and new investigations in the study of complex biomedical and physiologic signals. It offers free...

Pro Agile NET Development with Scrum

CERN Document Server

Blankenship, Jerrel; Millett, Scott

2011-01-01

Pro Agile .NET Development with SCRUM guides you through a real-world ASP.NET project and shows how agile methodology is put into practice. There is plenty of literature on the theory behind agile methodologies, but no book on the market takes the concepts of agile practices and applies these in a practical manner to an end-to-end ASP.NET project, especially the estimating, requirements and management aspects of a project. Pro Agile .NET Development with SCRUM takes you through the initial stages of a project - gathering requirements and setting up an environment - through to the development a

KONVERGENSI DALAM PROGRAM NET CITIZEN JOURNALISM

Directory of Open Access Journals (Sweden)

Rhafidilla Vebrynda

2017-06-01

Full Text Available Di dalam artikel ini, peneliti ingin melihat perkembangan teknologi di Indonesia sebagai sebuah peluang untuk menjalankan sebuah program berita berbasis video kiriman masyarakat. Perkembangan teknologi tersebut adalah teknologi penyiaran, teknologi sosial media dan teknologi dalam proses produksi sebuah video. Di Indonesia, jumlah televisi semakin banyak. Setiap stasiun televisi harus bersaing untuk dapat bertahan hidup. Net TV merupakan sebuah stasiun televisi baru di Indonesia yang harus memiliki berbagai program unggulan baru agar dapat bersaing dengan televisi lainnya yang sudah ada. Net TV menggunakan berbagai platform media untuk menjalankan program Net Citizen Journalism (Net CJ. Penggunaan berbagai platform media dikenal dengan istilah multiplatform dan secara teoritis dikenal dengan istilah konvergensi. Konvergensi yaitu saat meleburnya domain-domain dalam berbagai media komunikasi. Artikel ini menggunakan metode studi kasus untuk melihat bagaimana konvergensi terjadi dalam proses pengelolaan program Net CJ. Teknik pengumpulan data adalah dengan wawancara mendalam, observasi dan studi dokumen. Wawancara mendalam dilakukan dari tiga sudut pandang yaitu dari pengelola program, pengguna/audience dan pengamat media. Penelitian ini menemukan bahwa dengan menggunakan berbagai platform media yang fungsinya berbeda, memiliki satu tujuan yang sama yaitu untuk menjalankan program Net CJ. Adapun berbagai platform dalam proses produksi program yaitu tayangan TV konvensional, streaming TV, website, aplikasi Net CJ, facebook, twitter, instagram dan path. Konvergensi media dijalankan dalam dua proses, yaitu proses produksi dan proses promosi program berita.

Primary production in a shallow water lake with special reference to a reed swamp

International Nuclear Information System (INIS)

Andersen, F.Oe.

1976-01-01

Phytoplankton gross primary production ( 14 C method) in the shallow, eutrophic Danish Lake Arresoe in 1973 was 980 g C m -2 . Calculated net primary production was near zero. Macrophyte net primary production was measured by harvesting the maximum biomass, and above ground values were between 420 and 1325 g ash free dry wt m -2 , while below ground values were between 2480 and 8570 g ash free dry wt m -2 . The reed swamps were mapped on aerial photographs, and the composition of the macrophyte vegetation was determined. A comparison of macrophyte vegetation in 1944 and 1972 showed a reduction in species diversity, especially of submerged species. The seasonal variations in physical and chemical data indicated strong eutrophication in Arresoe. (author)

Which family members use the best nets? An analysis of the condition of mosquito nets and their distribution within households in Tanzania

Directory of Open Access Journals (Sweden)

Lines Jo

2010-07-01

Full Text Available Abstract Background Household ownership of insecticide-treated mosquito nets (ITNs is increasing, and coverage targets have been revised to address universal coverage with ITNs. However, many households do not have enough nets to cover everyone, and the nets available vary in physical condition and insecticide treatment status. Since 2004, the Government of Tanzania has been implementing the Tanzania National Voucher Scheme (TNVS, which distributes vouchers for ITNs through antenatal clinics to target pregnant women and their infants. This analysis aimed to determine the following: (1 coverage patterns of bed nets within households according to physical condition and treatment status; (2 who might be at risk if mosquitoes were diverted from occupants of untreated nets to those not using nets? (3 the degree to which those at highest risk of malaria use the most protective nets. Methods Data from the 2006 TNVS household survey were analysed to assess within-household distribution of net use. The associations between net characteristics and net user were also evaluated. Multivariate analysis was applied to the relationship between the number of holes per net and user characteristics while adjusting for confounders. Results In households with a net:person ratio better than 1:4 (one net for every four household members, more than 80% of the people in such households reported using a net the previous night. ITNs were most likely to be used by infants, young children (1-4 y, and women of childbearing age; they were least likely to be used by older women (≥50 y, older children (5-14 y, and adult men. The nets used by infants and women of childbearing age were in better-than-average physical condition; the nets used by older women and older children were in worse-than-average condition; while young children and adult men used nets in intermediate (average condition. When adjusted for confounders, the nets used by young and older children had more holes

MMPM - Mars MetNet Precursor Mission

Science.gov (United States)

Harri, A.-M.; Schmidt, W.; Pichkhadze, K.; Linkin, V.; Vazquez, L.; Uspensky, M.; Polkko, J.; Genzer, M.; Lipatov, A.; Guerrero, H.; Alexashkin, S.; Haukka, H.; Savijarvi, H.; Kauhanen, J.

2008-09-01

We are developing a new kind of planetary exploration mission for Mars - MetNet in situ observation network based on a new semi-hard landing vehicle called the Met-Net Lander (MNL). The eventual scope of the MetNet Mission is to deploy some 20 MNLs on the Martian surface using inflatable descent system structures, which will be supported by observations from the orbit around Mars. Currently we are working on the MetNet Mars Precursor Mission (MMPM) to deploy one MetNet Lander to Mars in the 2009/2011 launch window as a technology and science demonstration mission. The MNL will have a versatile science payload focused on the atmospheric science of Mars. Detailed characterization of the Martian atmospheric circulation patterns, boundary layer phenomena, and climatology cycles, require simultaneous in-situ measurements by a network of observation posts on the Martian surface. The scientific payload of the MetNet Mission encompasses separate instrument packages for the atmospheric entry and descent phase and for the surface operation phase. The MetNet mission concept and key probe technologies have been developed and the critical subsystems have been qualified to meet the Martian environmental and functional conditions. Prototyping of the payload instrumentation with final dimensions was carried out in 2003-2006.This huge development effort has been fulfilled in collaboration between the Finnish Meteorological Institute (FMI), the Russian Lavoschkin Association (LA) and the Russian Space Research Institute (IKI) since August 2001. Currently the INTA (Instituto Nacional de Técnica Aeroespacial) from Spain is also participating in the MetNet payload development. To understand the behavior and dynamics of the Martian atmosphere, a wealth of simultaneous in situ observations are needed on varying types of Martian orography, terrain and altitude spanning all latitudes and longitudes. This will be performed by the Mars MetNet Mission. In addition to the science aspects the

The Definitive Guide to NetBeans Platform

CERN Document Server

Bock, Heiko

2009-01-01

The Definitive Guide to NetBeans(t) Platform is a thorough and definitive introduction to the NetBeans Platform, covering all its major APIs in detail, with relevant code examples used throughout. The original German book on which this title is based was well received. The NetBeans Platform Community has put together this English translation, which author Heiko Bock updated to cover the latest NetBeans Platform 6.5 APIs. With an introduction by known NetBeans Platform experts Jaroslav Tulach, Tim Boudreau, and Geertjan Wielenga, this is the most up-to-date book on this topic at the moment. All

Spatio-Temporal Changes of Net Primary Productivity and its Response to Phenology in Northeast China during 2000-2015

Science.gov (United States)

Qiu, Y.; Zhang, L.; Fan, D.

2018-04-01

The relationship between net primary productivity (NPP) and phenological changes is of great significance to the study of regional ecosystem processes. In this study, firstly, NPP was estimated with the remote sensing model based on the SPOT-VGT NDVI dataset (2000-2015), meteorological data and the vegetation map in Northeast China. Then, using NDVI time series data which was reconstructed by polynomial fitting, phenology was extracted with the dynamic threshold method. Finally, the relationship between NPP and phenology was analyzed. The results showed that NPP mainly increased in the cropland, grassland, forestland and shrubland; however, vegetation NPP decreased in the ecotone among cropland, grassland and forestland. Correlation analysis suggested that the relationships between NPP and phenological metrics (i.e., the start of the growing season (SOS), the end of the growing season (EOS), the length of the growing season (LOS)) were different due to geographical location. On the whole, there was a positive correlation between NPP and the LOS in the forestland, and negative in the cropland and grassland, indicating that extended LOS can promote the accumulation of forestland NPP. By analyzing the monthly NDVI data during the vigorous growth period, the increase of NPP in the grassland and cropland was mainly due to the better growth from June to August, and shortened LOS did not lead to reduce the NPP. Generally, the response of NPP to phenology in Northeast China were more complex, showing obvious difference of vegetation types and spatial variability, we need to consider topography, community structure and other factors in the further studies.

Reliability ensemble averaging of 21st century projections of terrestrial net primary productivity reduces global and regional uncertainties

Science.gov (United States)

Exbrayat, Jean-François; Bloom, A. Anthony; Falloon, Pete; Ito, Akihiko; Smallman, T. Luke; Williams, Mathew

2018-02-01

Multi-model averaging techniques provide opportunities to extract additional information from large ensembles of simulations. In particular, present-day model skill can be used to evaluate their potential performance in future climate simulations. Multi-model averaging methods have been used extensively in climate and hydrological sciences, but they have not been used to constrain projected plant productivity responses to climate change, which is a major uncertainty in Earth system modelling. Here, we use three global observationally orientated estimates of current net primary productivity (NPP) to perform a reliability ensemble averaging (REA) method using 30 global simulations of the 21st century change in NPP based on the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) business as usual emissions scenario. We find that the three REA methods support an increase in global NPP by the end of the 21st century (2095-2099) compared to 2001-2005, which is 2-3 % stronger than the ensemble ISIMIP mean value of 24.2 Pg C y-1. Using REA also leads to a 45-68 % reduction in the global uncertainty of 21st century NPP projection, which strengthens confidence in the resilience of the CO2 fertilization effect to climate change. This reduction in uncertainty is especially clear for boreal ecosystems although it may be an artefact due to the lack of representation of nutrient limitations on NPP in most models. Conversely, the large uncertainty that remains on the sign of the response of NPP in semi-arid regions points to the need for better observations and model development in these regions.

Visual Studio 2010 and NET 4 Six-in-One

CERN Document Server

Novak, Istvan; Granicz, Adam

2010-01-01

Complete coverage of all key .NET 4 and Visual Studio 2010 languages and technologies. .NET 4 is Microsoft's latest version of their core programming platform, and Visual Studio 2010 is the toolset that helps write .NET 4 applications. This comprehensive resource offers one-stop shopping for all you need to know to get productive with .NET 4. Experienced author and .NET guru Mitchel Sellers reviews all the important new features of .NET 4, including .NET charting and ASP.NET charting, ASP.NET dynamic data and jQuery, and the addition of F# as a supported package language. The expansive coverag

Which nets are being used: factors associated with mosquito net use in Amhara, Oromia and Southern Nations, Nationalities and Peoples' Regions of Ethiopia.

Science.gov (United States)

Ngondi, Jeremiah M; Graves, Patricia M; Gebre, Teshome; Mosher, Aryc W; Shargie, Estifanos B; Emerson, Paul M; Richards, Frank O

2011-04-17

There has been recent large scale-up of malaria control interventions in Ethiopia where transmission is unstable. While household ownership of long-lasting insecticidal nets (LLIN) has increased greatly, there are concerns about inadequate net use. This study aimed to investigate factors associated with net use at two time points, before and after mass distribution of nets. Two cross sectional surveys were carried out in 2006 and 2007 in Amhara, Oromia and SNNP regions. The latter was a sub-sample of the national Malaria Indicator Survey (MIS 3R). Each survey wave used multi-stage cluster random sampling with 25 households per cluster (224 clusters with 5,730 households in Baseline 2006 and 245 clusters with 5,910 households in MIS 3R 2007). Net ownership was assessed by visual inspection while net utilization was reported as use of the net the previous night. This net level analysis was restricted to households owning at least one net of any type. Logistic regression models of association between net use and explanatory variables including net type, age, condition, cost and other household characteristics were undertaken using generalized linear latent and mixed models (GLLAMM). A total of 3,784 nets in 2,430 households were included in the baseline 2006 analysis while the MIS 3R 2007 analysis comprised 5,413 nets in 3,328 households. The proportion of nets used the previous night decreased from 85.1% to 56.0% between baseline 2006 and MIS 3R 2007, respectively. Factors independently associated with increased proportion of nets used were: LLIN net type (at baseline 2006); indoor residual spraying (at MIS 3R 2007); and increasing wealth index at both surveys. At both baseline 2006 and MIS 3R 2007, reduced proportion of nets used was independently associated with increasing net age, increasing damage of nets, increasing household net density, and increasing altitude (>2,000 m). This study identified modifiable factors affecting use of nets that were consistent

Which nets are being used: factors associated with mosquito net use in Amhara, Oromia and Southern Nations, Nationalities and Peoples' Regions of Ethiopia

Directory of Open Access Journals (Sweden)

Mosher Aryc W

2011-04-01

Full Text Available Abstract Background There has been recent large scale-up of malaria control interventions in Ethiopia where transmission is unstable. While household ownership of long-lasting insecticidal nets (LLIN has increased greatly, there are concerns about inadequate net use. This study aimed to investigate factors associated with net use at two time points, before and after mass distribution of nets. Methods Two cross sectional surveys were carried out in 2006 and 2007 in Amhara, Oromia and SNNP regions. The latter was a sub-sample of the national Malaria Indicator Survey (MIS 3R. Each survey wave used multi-stage cluster random sampling with 25 households per cluster (224 clusters with 5,730 households in Baseline 2006 and 245 clusters with 5,910 households in MIS 3R 2007. Net ownership was assessed by visual inspection while net utilization was reported as use of the net the previous night. This net level analysis was restricted to households owning at least one net of any type. Logistic regression models of association between net use and explanatory variables including net type, age, condition, cost and other household characteristics were undertaken using generalized linear latent and mixed models (GLLAMM. Results A total of 3,784 nets in 2,430 households were included in the baseline 2006 analysis while the MIS 3R 2007 analysis comprised 5,413 nets in 3,328 households. The proportion of nets used the previous night decreased from 85.1% to 56.0% between baseline 2006 and MIS 3R 2007, respectively. Factors independently associated with increased proportion of nets used were: LLIN net type (at baseline 2006; indoor residual spraying (at MIS 3R 2007; and increasing wealth index at both surveys. At both baseline 2006 and MIS 3R 2007, reduced proportion of nets used was independently associated with increasing net age, increasing damage of nets, increasing household net density, and increasing altitude (>2,000 m. Conclusion This study identified

Expected Net Present Value, Expected Net Future Value, and the Ramsey Rule

OpenAIRE

Gollier, Christian

2010-01-01

Weitzman (1998) showed that when future interest rates are uncertain, using the expected net present value implies a term structure of discount rates that is decreasing to the smallest possible interest rate. On the contrary, using the expected net future value criteria implies an increasing term structure of discount rates up to the largest possible interest rate. We reconcile the two approaches by introducing risk aversion and utility maximization. We show that if the aggregate consumption ...

Discrete, continuous, and hybrid petri nets

CERN Document Server

David, René

2004-01-01

Petri nets do not designate a single modeling formalism. In fact, newcomers to the field confess sometimes to be a little puzzled by the diversity of formalisms that are recognized under this "umbrella". Disregarding some extensions to the theoretical modeling capabilities, and looking at the level of abstraction of the formalisms, Condition/Event, Elementary, Place/Transition, Predicate/Transition, Colored, Object Oriented... net systems are frequently encountered in the literature. On the other side, provided with appropriate interpretative extensions, Controled Net Systems, Marking Diagrams (the Petri net generalization of State Diagrams), or the many-many variants in which time can be explicitly incorporated -Time(d), Deterministic, (Generalized) Stochastic, Fuzzy...- are defined. This represents another way to define practical formalisms that can be obtained by the "cro- product" of the two mentioned dimensions. Thus Petri nets constitute a modeling paradigm, understandable in a broad sense as "the total...

NetProt: Complex-based Feature Selection.

Science.gov (United States)

Goh, Wilson Wen Bin; Wong, Limsoon

2017-08-04

Protein complex-based feature selection (PCBFS) provides unparalleled reproducibility with high phenotypic relevance on proteomics data. Currently, there are five PCBFS paradigms, but not all representative methods have been implemented or made readily available. To allow general users to take advantage of these methods, we developed the R-package NetProt, which provides implementations of representative feature-selection methods. NetProt also provides methods for generating simulated differential data and generating pseudocomplexes for complex-based performance benchmarking. The NetProt open source R package is available for download from https://github.com/gohwils/NetProt/releases/ , and online documentation is available at http://rpubs.com/gohwils/204259 .

MODIS-derived terrestrial primary production [chapter 28

Science.gov (United States)

Maosheng Zhao; Steven Running; Faith Ann Heinsch; Ramakrishna Nemani

2011-01-01

Temporal and spatial changes in terrestrial biological productivity have a large impact on humankind because terrestrial ecosystems not only create environments suitable for human habitation, but also provide materials essential for survival, such as food, fiber and fuel. A recent study estimated that consumption of terrestrial net primary production (NPP; a list of...

Net energy benefits of carbon nanotube applications

International Nuclear Information System (INIS)

Zhai, Pei; Isaacs, Jacqueline A.; Eckelman, Matthew J.

2016-01-01

Highlights: • Life cycle net energy benefits are examined. • CNT-enabled and the conventional technologies are compared. • Flash memory with CNT switches show significant positive net energy benefit. • Lithium-ion batteries with MWCNT cathodes show positive net energy benefit. • Lithium-ion batteries with SWCNT anodes tend to exhibit negative net energy benefit. - Abstract: Implementation of carbon nanotubes (CNTs) in various applications can reduce material and energy requirements of products, resulting in energy savings. However, processes for the production of carbon nanotubes (CNTs) are energy-intensive and can require extensive purification. In this study, we investigate the net energy benefits of three CNT-enabled technologies: multi-walled CNT (MWCNT) reinforced cement used as highway construction material, single-walled CNT (SWCNT) flash memory switches used in cell phones and CNT anodes and cathodes used in lithium-ion batteries used in electric vehicles. We explore the avoided or additional energy requirement in the manufacturing and use phases and estimate the life cycle net energy benefits for each application. Additional scenario analysis and Monte Carlo simulation of parameter uncertainties resulted in probability distributions of net energy benefits, indicating that net energy benefits are dependent on the application with confidence intervals straddling the breakeven line in some cases. Analysis of simulation results reveals that SWCNT switch flash memory and MWCNT Li-ion battery cathodes have statistically significant positive net energy benefits (α = 0.05) and SWCNT Li-ion battery anodes tend to have negative net energy benefits, while positive results for MWCNT-reinforced cement were significant only under an efficient CNT production scenario and a lower confidence level (α = 0.1).

Towards a Standard for Modular Petri Nets

DEFF Research Database (Denmark)

Kindler, Ekkart; Petrucci, Laure

2009-01-01

concepts could or should be subject to import and export in high-level Petri nets. In this paper, we formalise a minimal version of modular high-level Petri nets, which is based on the concepts of modular PNML. This shows that modular PNML can be formalised once a specific version of Petri net is fixed....... Moreover, we present and discuss some more advanced features of modular Petri nets that could be included in the standard. This way, we provide a formal foundation and a basis for a discussion of features to be included in the upcoming standard of a module concept for Petri nets in general and for high-level...

Petri Nets

Indian Academy of Sciences (India)

GENERAL I ARTICLE ... In Part 1 of this two-part article, we have seen im- ..... mable logic controller and VLSI arrays, office automation systems, workflow management systems, ... complex discrete event and real-time systems; and Petri nets.

Pro asynchronous programming with .NET

CERN Document Server

Blewett, Richard; Ltd, Rock Solid Knowledge

2014-01-01

Pro Asynchronous Programming with .NET teaches the essential skill of asynchronous programming in .NET. It answers critical questions in .NET application development, such as: how do I keep my program responding at all times to keep my users happy how do I make the most of the available hardware how can I improve performanceIn the modern world, users expect more and more from their applications and devices, and multi-core hardware has the potential to provide it. But it takes carefully crafted code to turn that potential into responsive, scalable applications.With Pro Asynchronous Programming

Neutrophil extracellular traps are pathogenic in primary graft dysfunction after lung transplantation.

Science.gov (United States)

Sayah, David M; Mallavia, Beñat; Liu, Fengchun; Ortiz-Muñoz, Guadalupe; Caudrillier, Axelle; DerHovanessian, Ariss; Ross, David J; Lynch, Joseph P; Saggar, Rajan; Ardehali, Abbas; Ware, Lorraine B; Christie, Jason D; Belperio, John A; Looney, Mark R

2015-02-15

Primary graft dysfunction (PGD) causes early mortality after lung transplantation and may contribute to late graft failure. No effective treatments exist. The pathogenesis of PGD is unclear, although both neutrophils and activated platelets have been implicated. We hypothesized that neutrophil extracellular traps (NETs) contribute to lung injury in PGD in a platelet-dependent manner. To study NETs in experimental models of PGD and in lung transplant patients. Two experimental murine PGD models were studied: hilar clamp and orthotopic lung transplantation after prolonged cold ischemia (OLT-PCI). NETs were assessed by immunofluorescence microscopy and ELISA. Platelet activation was inhibited with aspirin, and NETs were disrupted with DNaseI. NETs were also measured in bronchoalveolar lavage fluid and plasma from lung transplant patients with and without PGD. NETs were increased after either hilar clamp or OLT-PCI compared with surgical control subjects. Activation and intrapulmonary accumulation of platelets were increased in OLT-PCI, and platelet inhibition reduced NETs and lung injury, and improved oxygenation. Disruption of NETs by intrabronchial administration of DNaseI also reduced lung injury and improved oxygenation. In bronchoalveolar lavage fluid from human lung transplant recipients, NETs were more abundant in patients with PGD. NETs accumulate in the lung in both experimental and clinical PGD. In experimental PGD, NET formation is platelet-dependent, and disruption of NETs with DNaseI reduces lung injury. These data are the first description of a pathogenic role for NETs in solid organ transplantation and suggest that NETs are a promising therapeutic target in PGD.

Reductions of plant cover induced by sheep grazing change the above-belowground partition and chemistry of organic C stocks in arid rangelands of Patagonian Monte, Argentina.

Science.gov (United States)

Larreguy, C; Carrera, A L; Bertiller, M B

2017-09-01

The objective of this study was to estimate the size and chemical quality of the total organic C stock and its partition between above-belowground plant parts and soil at sites with different plant cover induced by sheep grazing in the arid Patagonian Monte. This study was conducted at six representative sites with increasing signs of canopy disturbance attributed to grazing pressure. We used faeces density as a proxy of grazing pressure at each site. We assessed the total plant cover, shrub and perennial grass cover, total standing aboveground biomass (AGB), litter mass and belowground biomass (BGB) at each site. We further estimated the content of organic C, lignin and soluble phenols in plant compartments and the content of organic C, organic C in humic substances (recalcitrant C) and water soluble C (labile C) in soil at each site. Total plant cover was significantly related to grazing pressure. Standing AGB and litter mass decreased with increasing canopy disturbance while BGB did not vary across sites. Total organic C stock and the organic C stock in standing AGB increased with increasing total plant, shrub, and perennial grass cover. The organic C stock in litter mass increased with increasing total plant and shrub cover, while the organic C stock in BGB did not vary across sites. Lignin content in plant compartments increased with increasing total and shrub cover, while soluble phenols content did not change across sites. The organic C stock and the water soluble C content in soil were positively associated with perennial grass cover. Changes in total plant cover induced by grazing pressure negatively affected the size of the total organic C stock, having minor impact on the size of belowground than aboveground components. The reduction of perennial grass cover was reflected in decreasing chemical quality of the organic C stock in soil. Accordingly, plant managerial strategies should not only be focused on the amount of organic C sequestered but also on the

Energy system analysis of a pilot net-zero exergy district

International Nuclear Information System (INIS)

Kılkış, Şiir

2014-01-01

Highlights: • Östra Sala backe is analyzed as a pilot district for the net-zero exergy target. • An analysis tool is developed for proposing an energy system for Östra Sala backe. • A total of 8 different measures are included and integrated in the energy system. • The exergy produced on-site is 49.7 GW h, the annual exergy consumed is 54.3 GW h. • The average value of the level of exergy match in the supply and demand is 0.84. - Abstract: The Rational Exergy Management Model (REMM) provides an analytical model to curb primary energy spending and CO 2 emissions by means of considering the level of match between the grade/quality of energy resources (exergy) on the supply and demand sides. This model is useful for developing forward-looking concepts with an energy systems perspective. One concept is net-zero exergy districts, which produce as much energy at the same grade or quality as consumed on an annual basis. This paper analyzes the district of Östra Sala backe in Uppsala Municipality in Sweden as a pilot, near net-zero exergy district. The district is planned to host 20,000 people at the end of four phases. The measures that are considered include an extension of the combined heat and power based district heating and cooling network, heat pumps driven on renewable energy, district heating driven white goods, smart home automation, efficient lighting, and bioelectricity driven public transport. A REMM Analysis Tool for net-zero exergy districts is developed and used to analyze 5 scenarios based on a Net-Zero Exergy District Option Index. According to the results, a pilot concept for the first phase of the project is proposed. This integrates a mix of 8 measures considering an annual electricity load of 46.0 GW h e and annual thermal load of 67.0 GW h t . The exergy that is produced on-site with renewable energy sources is 49.7 GW h and the annual exergy consumed is 54.3 GW h. The average value of the level of match between the demand and supply of

Plant species distribution along environmental gradient: do belowground interactions with fungi matter?

Directory of Open Access Journals (Sweden)

Loïc ePellissier

2013-12-01

Full Text Available The distribution of plants along environmental gradients is constrained by abiotic and biotic factors. Cumulative evidence attests of the impact of abiotic factors on plant distributions, but only few studies discuss the role of belowground communities. Soil fungi, in particular, are thought to play an important role in how plant species assemble locally into communities. We first review existing evidence, and then test the effect of the number of soil fungal operational taxonomic units (OTUs on plant species distributions using a recently collected dataset of plant and metagenomic information on soil fungi in the Western Swiss Alps. Using species distribution models, we investigated whether the distribution of individual plant species is correlated to the number of OTUs of two important soil fungal classes known to interact with plants: the Glomeromycetes, that are obligatory symbionts of plants, and the Agaricomycetes, that may be facultative plant symbionts, pathogens, or wood decayers. We show that including the fungal richness information in the models of plant species distributions improves predictive accuracy. Number of fungal OTUs is especially correlated to the distribution of high elevation plant species. We suggest that high elevation soil show greater variation in fungal assemblages that may in turn impact plant turnover among communities. We finally discuss how to move beyond correlative analyses, through the design of field experiments manipulating plant and fungal communities along environmental gradients.

Assessing the impact of urbanization on net primary productivity using multi-scale remote sensing data: a case study of Xuzhou, China

Science.gov (United States)

Tan, Kun; Zhou, Songyang; Li, Erzhu; Du, Peijun

2015-06-01

An improved Carnegie Ames Stanford Approach (CASA) model based on two kinds of remote sensing (RS) data, Landsat Enhanced Thematic Mapper Plus (ETM +) and Moderate Resolution Imaging Spectro-radiometer (MODIS), and climate variables were applied to estimate the Net Primary Productivity (NPP) of Xuzhou in June of each year from 2001 to 2010. The NPP of the study area decreased as the spatial scale increased. The average NPP of terrestrial vegetation in Xuzhou showed a decreasing trend in recent years, likely due to changes in climate and environment. The study area was divided into four sub-regions, designated as highest, moderately high, moderately low, and lowest in NPP. The area designated as the lowest sub-region in NPP increased with expanding scale, indicating that the NPP distribution varied with different spatial scales. The NPP of different vegetation types was also significantly influenced by scale. In particular, the NPP of urban woodland produced lower estimates because of mixed pixels. Similar trends in NPP were observed with different RS data. In addition, expansion of residential areas and reduction of vegetated areas were the major reasons for NPP change. Land cover changes in urban areas reduced NPP, which could chiefly be attributed to human-induced disturbance.

Clinical application of SPECT-CT with 99mTc-Tektrotyd in bronchial and thymic neuroendocrine tumors (NETs).

Science.gov (United States)

Sergieva, Sonya; Robev, Bozhil; Dimcheva, Milena; Fakirova, Albena; Hristoskova, Radka

2016-01-01

Neuroendocrine tumors (NETs) of the thorax including bronchial and thymic tumors belong to foregut NETs. Limited loco-regional thoracic NETs can be resected with surgery, but in extensive metastatic disease the treatment is mainly palliative. A high incidence and density of somatostatin receptors (SSTR2, SSTR3, and SSTR5) are found in thoracic NETs. The purpose of this study was to evaluate the role of SPECT-CT somatostatin receptor scintigraphy (SRS) with 99mTc-Tektrotyd for imaging, staging and follow up of patients with bronchial and thymic neuroendocrine tumors. Forty-one patients with thoracic tumors with neuroendocrine differentiation were studied. Sixty-eight examinations including SPECT-CT studies of the neck and chest and/or abdomen and pelvis were carried out 2-4 hrs. post i.v. administration of aver-age 740 MBq activity dose of 99mTc-EDDA/HYNIC-TOC (Tektrotyd, Polatom). In all 41 investigated patients we obtained 81.25% (13/16), 88% (22/25) and 85.36% (35/41) of sensitivity, specificity and accuracy of this diagnostic approach, respectively. Somatostatin-receptor scintigraphy correctly identified all primary NETs located in the lungs and thymus. SPECT-CT studies with 99mTc-EDDA/HYNIC-TOC resulted in exact pre-surgical and pre-treatment N/M staging of bronchial and thymic NETs, except 2 cases with multiple hepatic metastases and 1 with massive suprarenal metastasis. It can be concluded that SPECT-CT with 99mTc-EDDA/HYNIC-TOC is a valuable tool for staging and follow-up of patients with thoracic NETs.

Linear Logic on Petri Nets

DEFF Research Database (Denmark)

Engberg, Uffe Henrik; Winskel, Glynn

This article shows how individual Petri nets form models of Girard's intuitionistic linear logic. It explores questions of expressiveness and completeness of linear logic with respect to this interpretation. An aim is to use Petri nets to give an understanding of linear logic and give some apprai...

First study of the negative binomial distribution applied to higher moments of net-charge and net-proton multiplicity distributions

International Nuclear Information System (INIS)

Tarnowsky, Terence J.; Westfall, Gary D.

2013-01-01

A study of the first four moments (mean, variance, skewness, and kurtosis) and their products (κσ 2 and Sσ) of the net-charge and net-proton distributions in Au + Au collisions at √(s NN )=7.7–200 GeV from HIJING simulations has been carried out. The skewness and kurtosis and the collision volume independent products κσ 2 and Sσ have been proposed as sensitive probes for identifying the presence of a QCD critical point. A discrete probability distribution that effectively describes the separate positively and negatively charged particle (or proton and anti-proton) multiplicity distributions is the negative binomial (or binomial) distribution (NBD/BD). The NBD/BD has been used to characterize particle production in high-energy particle and nuclear physics. Their application to the higher moments of the net-charge and net-proton distributions is examined. Differences between κσ 2 and a statistical Poisson assumption of a factor of four (for net-charge) and 40% (for net-protons) can be accounted for by the NBD/BD. This is the first application of the properties of the NBD/BD to describe the behavior of the higher moments of net-charge and net-proton distributions in nucleus–nucleus collisions

TwiddleNet: Smartphones as Personal Servers

OpenAIRE

Gurminder, Singh; Center for the Study of Mobile Devices and Communications

2012-01-01

TwiddleNet uses smartphones as personal servers to enable instant content capture and dissemination for firstresponders. It supports the information sharing needs of first responders in the early stages of an emergency response operation. In TwiddleNet, content, once captured, is automatically tagged and disseminated using one of the several networking channels available in smartphones. TwiddleNet pays special attention to minimizing the equipment, network set-up time, and content...

Pro visual C++/CLI and the net 35 platform

CERN Document Server

Fraser, Stephen

2008-01-01

Pro Visual C++/CLI and the .NET 3.5 Platform is about writing .NET applications using C++/CLI. While readers are learning the ins and outs of .NET application development, they will also be learning the syntax of C++, both old and new to .NET. Readers will also gain a good understanding of the .NET architecture. This is truly a .NET book applying C++ as its development language not another C++ syntax book that happens to cover .NET.

SkyNet: Modular nuclear reaction network library

Science.gov (United States)

Lippuner, Jonas; Roberts, Luke F.

2017-10-01

The general-purpose nuclear reaction network SkyNet evolves the abundances of nuclear species under the influence of nuclear reactions. SkyNet can be used to compute the nucleosynthesis evolution in all astrophysical scenarios where nucleosynthesis occurs. Any list of isotopes can be evolved and SkyNet supports various different types of nuclear reactions. SkyNet is modular, permitting new or existing physics, such as nuclear reactions or equations of state, to be easily added or modified.

Elliptic net and its cryptographic application

Science.gov (United States)

Muslim, Norliana; Said, Mohamad Rushdan Md

2017-11-01

Elliptic net is a generalization of elliptic divisibility sequence and in cryptography field, most cryptographic pairings that are based on elliptic curve such as Tate pairing can be improved by applying elliptic nets algorithm. The elliptic net is constructed by using n dimensional array of values in rational number satisfying nonlinear recurrence relations that arise from elliptic divisibility sequences. The two main properties hold in the recurrence relations are for all positive integers m>n, hm +nhm -n=hm +1hm -1hn2-hn +1hn -1hm2 and hn divides hm whenever n divides m. In this research, we discuss elliptic divisibility sequence associated with elliptic nets based on cryptographic perspective and its possible research direction.

Future supply and demand of net primary production in the Sahel

Directory of Open Access Journals (Sweden)

F. Sallaba

2017-12-01

Full Text Available In the 21st century, climate change in combination with increasing demand, mainly from population growth, will exert greater pressure on the ecosystems of the Sahel to supply food and feed resources. The balance between supply and demand, defined as the annual biomass required for human consumption, serves as a key metric for quantifying basic resource shortfalls over broad regions.Here we apply an exploratory modelling framework to analyse the variations in the timing and geography of different NPP (net primary production supply–demand scenarios, with distinct assumptions determining supply and demand, for the 21st century Sahel. We achieve this by coupling a simple NPP supply model forced with projections from four representative concentration pathways with a global, reduced-complexity demand model driven by socio-economic data and assumptions derived from five shared socio-economic pathways.For the scenario that deviates least from current socio-economic and climate trends, we find that per capita NPP begins to outstrip supply in the 2040s, while by 2050 half the countries in the Sahel experience NPP shortfalls. We also find that despite variations in the timing of the onset of NPP shortfalls, demand cannot consistently be met across the majority of scenarios. Moreover, large between-country variations are shown across the scenarios, in which by the year 2050 some countries consistently experience shortage or surplus, while others shift from surplus to shortage. At the local level (i.e. grid cell, hotspots of total NPP shortfall consistently occur in the same locations across all scenarios but vary in size and magnitude. These hotspots are linked to population density and high demand. For all scenarios, total simulated NPP supply doubles by 2050 but is outpaced by increasing demand due to a combination of population growth and the adoption of diets rich in animal products. Finally, variations in the timing of the onset and end of supply

Annual net primary productivity of a cyanobacteria-dominated biological soil crust in the Gulf Savannah, Queensland, Australia

Science.gov (United States)

Büdel, Burkhard; Williams, Wendy J.; Reichenberger, Hans

2018-01-01

Biological soil crusts (biocrusts) are a common element of the Queensland (Australia) dry savannah ecosystem and are composed of cyanobacteria, algae, lichens, bryophytes, fungi and heterotrophic bacteria. Here we report how the CO2 gas exchange of the cyanobacteria-dominated biocrust type from Boodjamulla National Park in the north Queensland Gulf Savannah responds to the pronounced climatic seasonality and on their quality as a carbon sink using a semi-automatic cuvette system. The dominant cyanobacteria are the filamentous species Symplocastrum purpurascens together with Scytonema sp. Metabolic activity was recorded between 1 July 2010 and 30 June 2011, during which CO2 exchange was only evident from November 2010 until mid-April 2011, representative of 23.6 % of the 1-year recording period. In November at the onset of the wet season, the first month (November) and the last month (April) of activity had pronounced respiratory loss of CO2. The metabolic active period accounted for 25 % of the wet season and of that period 48.6 % was net photosynthesis (NP) and 51.4 % dark respiration (DR). During the time of NP, net photosynthetic uptake of CO2 during daylight hours was reduced by 32.6 % due to water supersaturation. In total, the biocrust fixed 229.09 mmol CO2 m-2 yr-1, corresponding to an annual carbon gain of 2.75 g m-2 yr-1. Due to malfunction of the automatic cuvette system, data from September and October 2010 together with some days in November and December 2010 could not be analysed for NP and DR. Based on climatic and gas exchange data from November 2010, an estimated loss of 88 mmol CO2 m-2 was found for the 2 months, resulting in corrected annual rates of 143.1 mmol CO2 m-2 yr-1, equivalent to a carbon gain of 1.7 g m-2 yr-1. The bulk of the net photosynthetic activity occurred above a relative humidity of 42 %, indicating a suitable climatic combination of temperature, water availability and light intensity well above 200 µmol photons m-2 s-1

Net neutrality and audiovisual services

NARCIS (Netherlands)

van Eijk, N.; Nikoltchev, S.

2011-01-01

Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication

Inferring Phylogenetic Networks Using PhyloNet.

Science.gov (United States)

Wen, Dingqiao; Yu, Yun; Zhu, Jiafan; Nakhleh, Luay

2018-07-01

PhyloNet was released in 2008 as a software package for representing and analyzing phylogenetic networks. At the time of its release, the main functionalities in PhyloNet consisted of measures for comparing network topologies and a single heuristic for reconciling gene trees with a species tree. Since then, PhyloNet has grown significantly. The software package now includes a wide array of methods for inferring phylogenetic networks from data sets of unlinked loci while accounting for both reticulation (e.g., hybridization) and incomplete lineage sorting. In particular, PhyloNet now allows for maximum parsimony, maximum likelihood, and Bayesian inference of phylogenetic networks from gene tree estimates. Furthermore, Bayesian inference directly from sequence data (sequence alignments or biallelic markers) is implemented. Maximum parsimony is based on an extension of the "minimizing deep coalescences" criterion to phylogenetic networks, whereas maximum likelihood and Bayesian inference are based on the multispecies network coalescent. All methods allow for multiple individuals per species. As computing the likelihood of a phylogenetic network is computationally hard, PhyloNet allows for evaluation and inference of networks using a pseudolikelihood measure. PhyloNet summarizes the results of the various analyzes and generates phylogenetic networks in the extended Newick format that is readily viewable by existing visualization software.

Successful range-expanding plants experience less above-ground and below-ground enemy impact.

Science.gov (United States)

Engelkes, Tim; Morriën, Elly; Verhoeven, Koen J F; Bezemer, T Martijn; Biere, Arjen; Harvey, Jeffrey A; McIntyre, Lauren M; Tamis, Wil L M; van der Putten, Wim H

2008-12-18

Many species are currently moving to higher latitudes and altitudes. However, little is known about the factors that influence the future performance of range-expanding species in their new habitats. Here we show that range-expanding plant species from a riverine area were better defended against shoot and root enemies than were related native plant species growing in the same area. We grew fifteen plant species with and without non-coevolved polyphagous locusts and cosmopolitan, polyphagous aphids. Contrary to our expectations, the locusts performed more poorly on the range-expanding plant species than on the congeneric native plant species, whereas the aphids showed no difference. The shoot herbivores reduced the biomass of the native plants more than they did that of the congeneric range expanders. Also, the range-expanding plants developed fewer pathogenic effects in their root-zone soil than did the related native species. Current predictions forecast biodiversity loss due to limitations in the ability of species to adjust to climate warming conditions in their range. Our results strongly suggest that the plants that shift ranges towards higher latitudes and altitudes may include potential invaders, as the successful range expanders may experience less control by above-ground or below-ground enemies than the natives.

County community health associations of net voting shift in the 2016 U.S. presidential election.

Directory of Open Access Journals (Sweden)

Jason H Wasfy

Full Text Available In the U.S. presidential election of 2016, substantial shift in voting patterns occurred relative to previous elections. Although this shift has been associated with both education and race, the extent to which this shift was related to public health status is unclear.To determine the extent to which county community health was associated with changes in voting between the presidential elections of 2016 and 2012.Ecological study with principal component analysis (PCA using principal axis method to extract the components, then generalized linear regression.General community.All counties in the United States.Physically unhealthy days, mentally unhealthy days, percent food insecure, teen birth rate, primary care physician visit rate, age-adjusted mortality rate, violent crime rate, average health care costs, percent diabetic, and percent overweight or obese.The percentage of Donald Trump votes in 2016 minus percentage of Mitt Romney votes in 2012 ("net voting shift".Complete public health data was available for 3,009 counties which were included in the analysis. The mean net voting shift was 5.4% (+/- 5.8%. Of these 3,009 counties, 2,641 (87.8% had positive net voting shift (shifted towards Trump and 368 counties (12.2% had negative net voting shift (shifted away from Trump. The first principal component ("unhealthy score" accounted for 68% of the total variance in the data. The unhealthy score included all health variables except primary care physician rate, violent crime rate, and health care costs. The mean unhealthy score for counties was 0.39 (SD 0.16. Higher normalized unhealthy score was associated with positive net voting shift (22.1% shift per unit unhealthy, p < 0.0001. This association was stronger in states that switched Electoral College votes from 2012 to 2016 than in other states (5.9% per unit unhealthy, p <0.0001.Substantial association exists between a shift toward voting for Donald Trump in 2016 relative to Mitt Romney in 2012

Stimulation of terrestrial ecosystem carbon storage by nitrogen addition: a meta-analysis.

Science.gov (United States)

Yue, Kai; Peng, Yan; Peng, Changhui; Yang, Wanqin; Peng, Xin; Wu, Fuzhong

2016-01-27

Elevated nitrogen (N) deposition alters the terrestrial carbon (C) cycle, which is likely to feed back to further climate change. However, how the overall terrestrial ecosystem C pools and fluxes respond to N addition remains unclear. By synthesizing data from multiple terrestrial ecosystems, we quantified the response of C pools and fluxes to experimental N addition using a comprehensive meta-analysis method. Our results showed that N addition significantly stimulated soil total C storage by 5.82% ([2.47%, 9.27%], 95% CI, the same below) and increased the C contents of the above- and below-ground parts of plants by 25.65% [11.07%, 42.12%] and 15.93% [6.80%, 25.85%], respectively. Furthermore, N addition significantly increased aboveground net primary production by 52.38% [40.58%, 65.19%] and litterfall by 14.67% [9.24%, 20.38%] at a global scale. However, the C influx from the plant litter to the soil through litter decomposition and the efflux from the soil due to microbial respiration and soil respiration showed insignificant responses to N addition. Overall, our meta-analysis suggested that N addition will increase soil C storage and plant C in both above- and below-ground parts, indicating that terrestrial ecosystems might act to strengthen as a C sink under increasing N deposition.

Net Neutrality: Media Discourses and Public Perception

Directory of Open Access Journals (Sweden)

Christine Quail

2010-01-01

Full Text Available This paper analyzes media and public discourses surrounding net neutrality, with particular attention to public utility philosophy, from a critical perspective. The article suggests that further public education about net neutrality would be beneficial. The first portion of this paper provides a survey of the existing literature surrounding net neutrality, highlighting the contentious debate between market-based and public interest perspectives. In order to contextualize the debate, an overview of public utility philosophy is provided, shedding light on how the Internet can be conceptualized as a public good. Following this discussion, an analysis of mainstream media is presented, exploring how the media represents the issue of net neutrality and whether or not the Internet is discussed through the lens of public utility. To further examine how the net neutrality debate is being addressed, and to see the potential impacts of media discourses on the general public, the results of a focus group are reported and analyzed. Finally, a discussion assesses the implications of the net neutrality debate as presented through media discourses, highlighting the future of net neutrality as an important policy issue.

NET system integration

International Nuclear Information System (INIS)

Farfaletti-Casali, F.; Mitchell, N.; Salpietro, E.; Buzzi, U.; Gritzmann, P.

1985-01-01

The NET system integration procedure is the process by which the requirements of the various Tokamak machine design areas are brought together to form a compatible machine layout. Each design area produces requirements which generally allow components to be built at minimum cost and operate with minimum technical risk, and the final machine assembly should be achieved with minimum departure from these optimum designs. This is carried out in NET by allowing flexibility in the maintenance and access methods to the machine internal components which must be regularly replaced by remote handling, in segmentation of these internal components and in the number of toroidal field coils

Conformal Nets II: Conformal Blocks

Science.gov (United States)

Bartels, Arthur; Douglas, Christopher L.; Henriques, André

2017-08-01

Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

Putting Petri nets to work in Industry

NARCIS (Netherlands)

Aalst, van der W.M.P.

1994-01-01

Petri nets exist for over 30 years. Especially in the last decade Petri nets have been put into practive extensively. Thanks to several useful extensions and the availability of computer tools, Petri nets have become a mature tool for modelling and analysing industrial systems. This paper describes

Net Gain

International Development Research Centre (IDRC) Digital Library (Canada)

Describing the effect of tax incentives for import, production, and sale of nets and insecticides; and ..... So far, China is the only country where a system for the routine treatment of ...... 1993), and the trials in Ecuador and Peru (Kroeger et al.

Mars MetNet Precursor Mission Status

Science.gov (United States)

Harri, A.-M.; Aleksashkin, S.; Guerrero, H.; Schmidt, W.; Genzer, M.; Vazquez, L.; Haukka, H.

2013-09-01

We are developing a new kind of planetary exploration mission for Mars in collaboration between the Finnish Meteorological Institute (FMI), Lavochkin Association (LA), Space Research Institute (IKI) and Institutio Nacional de Tecnica Aerospacial (INTA). The Mars MetNet mission is based on a new semi-hard landing vehicle called MetNet Lander (MNL). The scientific payload of the Mars MetNet Precursor [1] mission is divided into three categories: Atmospheric instruments, Optical devices and Composition and structure devices. Each of the payload instruments will provide significant insights in to the Martian atmospheric behavior. The key technologies of the MetNet Lander have been qualified and the electrical qualification model (EQM) of the payload bay has been built and successfully tested.

SolNet

DEFF Research Database (Denmark)

Jordan, Ulrike; Vajen, Klaus; Bales, Chris

2014-01-01

-accompanying Master courses, placements of internships, and PhD scholarship projects. A new scholarship project, “SHINE”, was launched in autumn 2013 in the frame work of the Marie Curie program of the European Union (Initial Training Network, ITN). 13 PhD-scholarships on solar district heating, solar heat......SolNet, founded in 2006, is the first coordinated International PhD education program on Solar Thermal Engineering. The SolNet network is coordinated by the Institute of Thermal Engineering at Kassel University, Germany. The network offers PhD courses on solar heating and cooling, conference...... for industrial processes, as well as sorption stores and materials started in December 2013. Additionally, the project comprises a training program with five PhD courses and several workshops on solar thermal engineering that will be open also for other PhD students working in the field. The research projects...

Allometry and partitioning of above- and below-ground biomass in farmed eucalyptus species dominant in Western Kenyan agricultural landscapes

International Nuclear Information System (INIS)

Kuyah, Shem; Dietz, Johannes; Muthuri, Catherine; Noordwijk, Meine van; Neufeldt, Henry

2013-01-01

Farmers in developing countries are one of the world's largest and most efficient producers of sequestered carbon. However, measuring, monitoring and verifying how much carbon trees in smallholder farms are removing from the atmosphere has remained a great challenge in developing nations. Devising a reliable way for measuring carbon associated with trees in agricultural landscapes is essential for helping smallholder farmers benefit from emerging carbon markets. This study aimed to develop biomass equations specific to dominant eucalyptus species found in agricultural landscapes in Western Kenya. Allometric relationships were developed by regressing diameter at breast height (DBH) alone or DBH in combination with height, wood density or crown area against the biomass of 48 trees destructively sampled from a 100 km 2 site. DBH alone was a significant predictor variable and estimated aboveground biomass (AGB) with over 95% accuracy. The stems, branches and leaves formed up to 74, 22 and 4% of AGB, respectively, while belowground biomass (BGB) of the harvested trees accounted for 21% of the total tree biomass, yielding an overall root-to-shoot ratio (RS) of 0.27, which varied across tree size. Total tree biomass held in live Eucalyptus trees was estimated to be 24.4 ± 0.01 Mg ha −1 , equivalent to 11.7 ± 0.01 Mg of carbon per hectare. The equations presented provide useful tools for estimating tree carbon stocks of Eucalyptus in agricultural landscapes for bio-energy and carbon accounting. These equations can be applied to Eucalyptus in most agricultural systems with similar agro-ecological settings where tree growth parameters would fall within ranges comparable to the sampled population. -- Highlights: ► Equation with DBH alone estimated aboveground biomass with about 95% accuracy. ► Local generic equations overestimated above- and below-ground biomass by 10 and 48%. ► Height, wood density and crown area data did not improve model accuracy. ► Stems

Symmetric Cryptosystem Based on Petri Net

Directory of Open Access Journals (Sweden)

Hussein ‎ A. Lafta

2017-12-01

Full Text Available In this wok, a novel approach based on ordinary Petri net is used to generate private key . The reachability marking  of petri net is used as encryption/decryption key to provide more complex key . The same ordinary Petri Nets models  are used for the sender(encryption and  the receiver(decryption.The plaintext has been permutated  using  look-up table ,and XOR-ed with key to generate cipher text

Net Pay Estimator | Alaska Division of Retirement and Benefits

Science.gov (United States)

Benefits > Net Pay Estimator Online Counselor Scheduler Empower Retirement Account Info Online myRnB Accessibility Net Pay Estimator Click here for the Retiree Net Pay Estimator? The net pay estimator is a useful tool to estimate your net pay under different salaries, federal withholding tax exemptions, and

CPN Tools-Assisted Simulation and Verification of Nested Petri Nets

Directory of Open Access Journals (Sweden)

L. W. Dworza´nski

2012-01-01

Full Text Available Nested Petri nets (NP-nets are an extension of Petri net formalism within the “netswithin-nets” approach, when tokens in a marking are Petri nets, which have an autonomous behavior and are synchronized with the system net. The formalism of NP-nets allows modeling multi-level multi-agent systems with dynamic structure in a natural way. Currently, there is no tool for supporting NP-nets simulation and analysis. The paper proposes the translation of NP-nets into Colored Petri nets and the use of CPN Tools as a virtual machine for NP-nets modeling, simulation and automatic verification.

Special Section on Coloured Petri Nets

DEFF Research Database (Denmark)

1998-01-01

Special section on coloured Petri nets, their basic concepts, analysis methods, tool support and industrial applications.......Special section on coloured Petri nets, their basic concepts, analysis methods, tool support and industrial applications....

Isotopic tracers for net primary productivity for a terrestrial ecosystem: a case study of the Volta River basin

International Nuclear Information System (INIS)

Hayford, E.K.; Odamtten, G.T.; Enu-Kwesi, L.

2006-01-01

The coupling effect of vapour release and CO2 uptake during photosynthesis plays an important role in the carbon and hydrologic cycles. The water use efficiency (WUE) for transpiration was used in calculating the net primary productivity (NPP) for terrestrial ecosystem. Three parameters were used in calculating the water and carbon balance of the River Volta watershed. These are 1) stable isotopes of hydrogen and oxygen, 2) long-term data on precipitation and evapotranspiration, and 3) stoichiometric relations of water and carbon. Results indicate that soils in the watershed annually respire 0.199 Pg C, and that the NPP is +0.029 Pg C yr-1. This implies an annual change in CO2 to the atmosphere within the watershed. Annually, River Volta watershed receives about 380 km3 of rainfall; approximately 50 per cent of which is returned to the atmosphere through plant transpiration. Associated with annual transpiration flux is a carbon flux of 0.170 x 1015 g C yr-1 or 428 g C m-2 yr-1 from the terrestrial ecosystem. Modeled estimates of heterotrophic soil respiration exceeds slightly the estimated NPP values, implying that carbon flux to and from the Volta river watershed is close to being in balance. In other words, the watershed releases annually more carbon dioxide to the atmosphere than it takes. Apart from the terrestrial carbon flux, the balance of photosynthesis and respiration in the Volta lake was also examined. The lake was found to release carbon dioxide to the atmosphere although the magnitude of the flux is smaller than that of the terrestrial ecosystem. (au)

The Petri Net Markup Language : concepts, technology, and tools

NARCIS (Netherlands)

Billington, J.; Christensen, S.; Hee, van K.M.; Kindler, E.; Kummer, O.; Petrucci, L.; Post, R.D.J.; Stehno, C.; Weber, M.; Aalst, van der W.M.P.; Best, E.

2003-01-01

The Petri Net Markup Language (PNML) is an XML-based interchange format for Petri nets. In order to support different versions of Petri nets and, in particular, future versions of Petri nets, PNML allows the definition of Petri net types.Due to this flexibility, PNML is a starting point for a

Belowground interactions with aboveground consequences: Invasive earthworms and arbuscular mycorrhizal fungi.

Science.gov (United States)

Paudel, Shishir; Longcore, Travis; MacDonald, Beau; McCormick, Melissa K; Szlavecz, Katalin; Wilson, Gail W T; Loss, Scot R

2016-03-01

A mounting body of research suggests that invasive nonnative earthworms substantially alter microbial communities, including arbuscular mycorrhizal fungi (AMF). These changes to AMF can cascade to affect plant communities and vertebrate populations. Despite these research advances, relatively little is known about (1) the mechanisms behind earthworms' effects on AMF and (2) the factors that determine the outcomes of earthworm-AMF interactions (i.e., whether AMF abundance is increased or decreased and subsequent effects on plants). We predict that AMF-mediated effects of nonnative earthworms on ecosystems are nearly universal because (1) AMF are important components of most terrestrial ecosystems, (2) nonnative earthworms have become established in nearly every type of terrestrial ecosystem, and (3) nonnative earthworms, due to their burrowing and feeding behavior, greatly affect AMF with potentially profound concomitant effects on plant communities. We highlight the multiple direct and indirect effects of nonnative earthworms on plants and review what is currently known about the interaction between earthworms and AMF. We also illustrate how the effects of nonnative earthworms on plant-AMF mutualisms can alter the structure and stability of aboveground plant communities, as well as the vertebrate communities relying on these habitats. Integrative studies that assess the interactive effects of earthworms and AMF can provide new insights into the role that belowground ecosystem engineers play in altering aboveground ecological processes. Understanding these processes may improve our ability to predict the structure of plant and animal communities in earthworm-invaded regions and to develop management strategies that limit the numerous undesired impacts of earthworms.

BioNet Digital Communications Framework

Science.gov (United States)

Gifford, Kevin; Kuzminsky, Sebastian; Williams, Shea

2010-01-01

BioNet v2 is a peer-to-peer middleware that enables digital communication devices to talk to each other. It provides a software development framework, standardized application, network-transparent device integration services, a flexible messaging model, and network communications for distributed applications. BioNet is an implementation of the Constellation Program Command, Control, Communications and Information (C3I) Interoperability specification, given in CxP 70022-01. The system architecture provides the necessary infrastructure for the integration of heterogeneous wired and wireless sensing and control devices into a unified data system with a standardized application interface, providing plug-and-play operation for hardware and software systems. BioNet v2 features a naming schema for mobility and coarse-grained localization information, data normalization within a network-transparent device driver framework, enabling of network communications to non-IP devices, and fine-grained application control of data subscription band width usage. BioNet directly integrates Disruption Tolerant Networking (DTN) as a communications technology, enabling networked communications with assets that are only intermittently connected including orbiting relay satellites and planetary rover vehicles.

Holes in the safety net: a case study of access to prescription drugs and specialty care.

Science.gov (United States)

Stanley, Ava; Cantor, Joel C; Guarnaccia, Peter

2008-07-01

The health care safety net in the United States is intended to fill gaps in health care services for uninsured and other vulnerable populations. This paper presents a case study of New Brunswick, NJ, a small city rich in safety net resources, to examine the adequacy of the American model of safety net care. We find substantial gaps in access to care despite the presence of a medical school, an abundance of primary care and specialty physicians, two major teaching hospitals, a large federally qualified health center and other safety net resources in this community of about 50,000 residents. Using a blend of random-digit-dial and area probability sampling, a survey of 595 households was conducted in 2001 generating detailed information about the health, access to care, demographic and other characteristics of 1,572 individuals. Confirming the great depth of the New Brunswick health care safety net, the survey showed that more than one quarter of local residents reported a hospital or community clinic as their usual source of care. Still, barriers to prescription drugs were reported for 11.0% of the area population and more than two in five (42.8%) local residents who perceived a need for specialty care reported difficulty getting those services. Bivariate analyses show significantly elevated risk of access problems among Hispanic and black residents, those in poor health, those relying on hospital and community clinics or with no usual source of care, and those living at or below poverty. In multivariate analysis, lack of health insurance was the greatest risk factor associated with both prescription drug and specialty access problems. Few local areas can claim the depth of safety net resources as New Brunswick, NJ, raising serious concerns about the adequacy of the American safety net model, especially for people with complex and chronic health care needs.

7 CFR 1221.17 - Net market value.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Net market value. 1221.17 Section 1221.17 Agriculture... INFORMATION ORDER Sorghum Promotion, Research, and Information Order Definitions § 1221.17 Net market value. Net market value means: (a) Except as provided in paragraph (b)and (c) of this section, the value...

NetBeans GUI Builder

OpenAIRE

Pusiankova, Tatsiana

2009-01-01

This work aims at making readers familiar with the powerful tool NetBeans IDE GUI Builder and helping them make their first steps to creation of their own graphical user interface in the Java programming language. The work includes theoretical description of NetBeans IDE GUI Builder, its most important characteristics and peculiarities and also a set of practical instructions that will help readers in creation of their first GUI. The readers will be introduced to the environment of this tool ...

Application and Theory of Petri Nets

DEFF Research Database (Denmark)

This volume contains the proceedings of the 13th International Conference onApplication and Theory of Petri Nets, held in Sheffield, England, in June 1992. The aim of the Petri net conferences is to create a forum for discussing progress in the application and theory of Petri nets. Typically....... Balbo and W. Reisig, 18 submitted papers, and seven project papers. The submitted papers and project presentations were selectedby the programme committee and a panel of referees from a large number of submissions....

Rotational KMS States and Type I Conformal Nets

Science.gov (United States)

Longo, Roberto; Tanimoto, Yoh

2018-01-01

We consider KMS states on a local conformal net on S 1 with respect to rotations. We prove that, if the conformal net is of type I, namely if it admits only type I DHR representations, then the extremal KMS states are the Gibbs states in an irreducible representation. Completely rational nets, the U(1)-current net, the Virasoro nets and their finite tensor products are shown to be of type I. In the completely rational case, we also give a direct proof that all factorial KMS states are Gibbs states.

Net charge fluctuations and local charge compensation

International Nuclear Information System (INIS)

Fu Jinghua

2006-01-01

We propose net charge fluctuation as a measure of local charge correlation length. It is demonstrated that, in terms of a schematic multiperipheral model, net charge fluctuation satisfies the same Quigg-Thomas relation as satisfied by charge transfer fluctuation. Net charge fluctuations measured in finite rapidity windows depend on both the local charge correlation length and the size of the observation window. When the observation window is larger than the local charge correlation length, the net charge fluctuation only depends on the local charge correlation length, while forward-backward charge fluctuations always have strong dependence on the observation window size. Net charge fluctuations and forward-backward charge fluctuations measured in the present heavy ion experiments show characteristic features similar to those from multiperipheral models. But the data cannot all be understood within this simple model

Long Term RadNet Quality Data

Data.gov (United States)

U.S. Environmental Protection Agency — This RadNet Quality Data Asset includes all data since initiation and when ERAMS was expanded to become RadNet, name changed to reflect new mission. This includes...

Petri Nets

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 9. Petri Nets - Applications. Y Narahari. General Article Volume 4 Issue 9 September 1999 pp 44-52 ... Author Affiliations. Y Narahari1. Department of Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India.

Belowground advantages in construction cost facilitate a cryptic plant invasion.

Science.gov (United States)

Caplan, Joshua S; Wheaton, Christine N; Mozdzer, Thomas J

2014-04-30

The energetic cost of plant organ construction is a functional trait that is useful for understanding carbon investment during growth (e.g. the resource acquisition vs. tissue longevity tradeoff), as well as in response to global change factors like elevated CO2 and N. Despite the enormous importance of roots and rhizomes in acquiring soil resources and responding to global change, construction costs have been studied almost exclusively in leaves. We sought to determine how construction costs of aboveground and belowground organs differed between native and introduced lineages of a geographically widely dispersed wetland plant species (Phragmites australis) under varying levels of CO2 and N. We grew plants under ambient and elevated atmospheric CO2, as well as under two levels of soil nitrogen. We determined construction costs for leaves, stems, rhizomes and roots, as well as for whole plants. Across all treatment conditions, the introduced lineage of Phragmites had a 4.3 % lower mean rhizome construction cost than the native. Whole-plant construction costs were also smaller for the introduced lineage, with the largest difference in sample means (3.3 %) occurring under ambient conditions. In having lower rhizome and plant-scale construction costs, the introduced lineage can recoup its investment in tissue construction more quickly, enabling it to generate additional biomass with the same energetic investment. Our results suggest that introduced Phragmites has had an advantageous tissue investment strategy under historic CO2 and N levels, which has facilitated key rhizome processes, such as clonal spread. We recommend that construction costs for multiple organ types be included in future studies of plant carbon economy, especially those investigating global change. Published by Oxford University Press on behalf of the Annals of Botany Company.

Ontological Annotation with WordNet

Energy Technology Data Exchange (ETDEWEB)

Sanfilippo, Antonio P.; Tratz, Stephen C.; Gregory, Michelle L.; Chappell, Alan R.; Whitney, Paul D.; Posse, Christian; Paulson, Patrick R.; Baddeley, Bob; Hohimer, Ryan E.; White, Amanda M.

2006-06-06

Semantic Web applications require robust and accurate annotation tools that are capable of automating the assignment of ontological classes to words in naturally occurring text (ontological annotation). Most current ontologies do not include rich lexical databases and are therefore not easily integrated with word sense disambiguation algorithms that are needed to automate ontological annotation. WordNet provides a potentially ideal solution to this problem as it offers a highly structured lexical conceptual representation that has been extensively used to develop word sense disambiguation algorithms. However, WordNet has not been designed as an ontology, and while it can be easily turned into one, the result of doing this would present users with serious practical limitations due to the great number of concepts (synonym sets) it contains. Moreover, mapping WordNet to an existing ontology may be difficult and requires substantial labor. We propose to overcome these limitations by developing an analytical platform that (1) provides a WordNet-based ontology offering a manageable and yet comprehensive set of concept classes, (2) leverages the lexical richness of WordNet to give an extensive characterization of concept class in terms of lexical instances, and (3) integrates a class recognition algorithm that automates the assignment of concept classes to words in naturally occurring text. The ensuing framework makes available an ontological annotation platform that can be effectively integrated with intelligence analysis systems to facilitate evidence marshaling and sustain the creation and validation of inference models.

SPATIO-TEMPORAL CHANGES OF NET PRIMARY PRODUCTIVITY AND ITS RESPONSE TO PHENOLOGY IN NORTHEAST CHINA DURING 2000–2015

Directory of Open Access Journals (Sweden)

Y. Qiu

2018-04-01

Full Text Available The relationship between net primary productivity (NPP and phenological changes is of great significance to the study of regional ecosystem processes. In this study, firstly, NPP was estimated with the remote sensing model based on the SPOT-VGT NDVI dataset (2000–2015, meteorological data and the vegetation map in Northeast China. Then, using NDVI time series data which was reconstructed by polynomial fitting, phenology was extracted with the dynamic threshold method. Finally, the relationship between NPP and phenology was analyzed. The results showed that NPP mainly increased in the cropland, grassland, forestland and shrubland; however, vegetation NPP decreased in the ecotone among cropland, grassland and forestland. Correlation analysis suggested that the relationships between NPP and phenological metrics (i.e., the start of the growing season (SOS, the end of the growing season (EOS, the length of the growing season (LOS were different due to geographical location. On the whole, there was a positive correlation between NPP and the LOS in the forestland, and negative in the cropland and grassland, indicating that extended LOS can promote the accumulation of forestland NPP. By analyzing the monthly NDVI data during the vigorous growth period, the increase of NPP in the grassland and cropland was mainly due to the better growth from June to August, and shortened LOS did not lead to reduce the NPP. Generally, the response of NPP to phenology in Northeast China were more complex, showing obvious difference of vegetation types and spatial variability, we need to consider topography, community structure and other factors in the further studies.