Potential impacts of climate change on the primary production of regional seas: A comparative analysis of five European seas

Science.gov (United States)

Holt, Jason; Schrum, Corinna; Cannaby, Heather; Daewel, Ute; Allen, Icarus; Artioli, Yuri; Bopp, Laurent; Butenschon, Momme; Fach, Bettina A.; Harle, James; Pushpadas, Dhanya; Salihoglu, Baris; Wakelin, Sarah

2016-01-01

Regional seas are potentially highly vulnerable to climate change, yet are the most directly societally important regions of the marine environment. The combination of widely varying conditions of mixing, forcing, geography (coastline and bathymetry) and exposure to the open-ocean makes these seas subject to a wide range of physical processes that mediates how large scale climate change impacts on these seas' ecosystems. In this paper we explore the response of five regional sea areas to potential future climate change, acting via atmospheric, oceanic and terrestrial vectors. These include the Barents Sea, Black Sea, Baltic Sea, North Sea, Celtic Seas, and are contrasted with a region of the Northeast Atlantic. Our aim is to elucidate the controlling dynamical processes and how these vary between and within these seas. We focus on primary production and consider the potential climatic impacts on: long term changes in elemental budgets, seasonal and mesoscale processes that control phytoplankton's exposure to light and nutrients, and briefly direct temperature response. We draw examples from the MEECE FP7 project and five regional model systems each using a common global Earth System Model as forcing. We consider a common analysis approach, and additional sensitivity experiments. Comparing projections for the end of the 21st century with mean present day conditions, these simulations generally show an increase in seasonal and permanent stratification (where present). However, the first order (low- and mid-latitude) effect in the open ocean projections of increased permanent stratification leading to reduced nutrient levels, and so to reduced primary production, is largely absent, except in the NE Atlantic. Even in the two highly stratified, deep water seas we consider (Black and Baltic Seas) the increase in stratification is not seen as a first order control on primary production. Instead, results show a highly heterogeneous picture of positive and negative change

Work Environment and Productivity among Primary School Teachers ...

African Journals Online (AJOL)

User

International Multidisciplinary Journal, Ethiopia. Vol. 5 (5), Serial No. ... work environment of Nigeria primary school teachers to greater productivity ... changes on the structure and curriculum, recommend and prescribed teaching methods and ...

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

Changes in water chemistry and primary productivity of a reactor cooling reservoir (Par Pond)

International Nuclear Information System (INIS)

Tilly, L.J.

1975-01-01

Water chemistry and primary productivity of a reactor cooling reservoir have been studied for 8 years. Initially the primary productivity increased sixfold, and the dissolved solids doubled. The dissolved-solids increase appears to have been caused by additions of makeup water from the Savannah River and by evaporative concentration during the cooling process. As the dissolved-solids concentrations and the conductivity of makeup water leveled off, the primary productivity stabilized. Major cation and anion concentrations generally followed total dissolved solids through the increase and plateau; however, silica concentrations declined steadily during the initial period of increased plankton productivity. Standing crops of net seston and centrifuge seston did not increase during this initial period. The collective data show the effects of thermal input to a cooling reservoir, illustrate the need for limnological studies before reactor siting, and suggest the possibility of using makeup-water additions to power reactor cooling basins as a reservoir management tool

Inter-generational change in African elephant range use is associated with poaching risk, primary productivity and adult mortality.

Science.gov (United States)

Goldenberg, Shifra Z; Douglas-Hamilton, Iain; Wittemyer, George

2018-05-30

Repeated use of the same areas may benefit animals as they exploit familiar sites, leading to consistent home ranges over time that can span generations. Changing risk landscapes may reduce benefits associated with home range fidelity, however, and philopatric animals may alter movement in response to new pressures. Despite the importance of range changes to ecological and evolutionary processes, little tracking data have been collected over the long-term nor has range change been recorded in response to human pressures across generations. Here, we investigate the relationships between ecological, demographic and human variables and elephant ranging behaviour across generations using 16 years of tracking data from nine distinct female social groups in a population of elephants in northern Kenya that was heavily affected by ivory poaching during the latter half of the study. Nearly all groups-including those that did not experience loss of mature adults-exhibited a shift north over time, apparently in response to increased poaching in the southern extent of the study area. However, loss of mature adults appeared to be the primary indicator of range shifts and expansions, as generational turnover was a significant predictor of range size increases and range centroid shifts. Range expansions and northward shifts were associated with higher primary productivity and lower poached carcass densities, while westward shifts exhibited a trend to areas with higher values of primary productivity and higher poached carcass densities relative to former ranges. Together these results suggest a trade-off between resource access, mobility and safety. We discuss the relevance of these results to elephant conservation efforts and directions meriting further exploration in this disrupted society of a keystone species. © 2018 The Author(s).

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

Czech Academy of Sciences Publication Activity Database

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

2017-01-01

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

HANPP Collection: Human Appropriation of Net Primary Productivity as a Percentage of Net Primary Productivity

Data.gov (United States)

National Aeronautics and Space Administration — The Human Appropriation of Net Primary Productivity (HANPP) as a Percentage of Net Primary Product (NPP) portion of the HANPP Collection represents a map identifying...

Net primary productivity of subalpine meadows in Yosemite National Park in relation to climate variability

Science.gov (United States)

Peggy E. Moore; Jan W. van Wagtendonk; Julie L. Yee; Mitchel P. McClaran; David N. Cole; Neil K. McDougald; Matthew L. Brooks

2013-01-01

Subalpine meadows are some of the most ecologically important components of mountain landscapes, and primary productivity is important to the maintenance of meadow functions. Understanding how changes in primary productivity are associated with variability in moisture and temperature will become increasingly important with current and anticipated changes in climate....

[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.

Spatial-temporal changes in phytoplankton biomass and primary ...

African Journals Online (AJOL)

Spatial-temporal variations in phytoplankton primary production (PP) and biomass (B) were studied for a period of about one year, from July 1999 to July 2000. In addition, changes in corresponding environmental variables were examined. Sampling took place at two stations in Chwaka Bay, one located in mangrove areas, ...

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

Science.gov (United States)

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 (...

Recent Primary Production and Small Phytoplankton Contribution in the Yellow Sea during the Summer in 2016

Science.gov (United States)

Jang, Hyo Keun; Kang, Jae Jung; Lee, Jae Hyung; Kim, Myungjoon; Ahn, So Hyun; Jeong, Jin-Yong; Yun, Mi Sun; Han, In-Seong; Lee, Sang Heon

2018-05-01

The high nutrient concentration associated with the mixing dynamics of two warm and cold water masses supports high primary production in the Yellow Sea. Although various environmental changes have been reported, no recent information on small phytoplankton contribution to the total primary production as an important indicator for marine ecosystem changes is currently available in the Yellow Sea. The major objective of this study is to determine the small (values decades ago. The higher contributions of small phytoplankton to the total chlorophyll a concentration and primary production might be caused by P-limited conditions and this resulted in lower chlorophyll a concentration and total primary production in this study compared to previous studies.

Primary production in the Delta: Then and now

Science.gov (United States)

Cloern, James E.; Robinson, April; Richey, Amy; Grenier, Letitia; Grossinger, Robin; Boyer, Katharyn E.; Burau, Jon; Canuel, Elizabeth A.; DeGeorge, John F.; Drexler, Judith Z.; Enright, Chris; Howe, Emily R.; Kneib, Ronald; Mueller-Solger, Anke; Naiman, Robert J.; Pinckney, James L.; Safran, Samuel M.; Schoellhamer, David H.; Simenstad, Charles A.

2016-01-01

To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it is unclear whether this was always the case. Recent analyses from the Historical Ecology Team and Delta Landscapes Project provide quantitative comparisons of the areal extent of 14 habitat types in the modern Delta versus the historical Delta (pre-1850). Here we describe an approach for using these metrics of land use change to: (1) produce the first quantitative estimates of how Delta primary production and the relative contributions from five different producer groups have been altered by large-scale drainage and conversion to agriculture; (2) convert these production estimates into a common currency so the contributions of each producer group reflect their food quality and efficiency of transfer to consumers; and (3) use simple models to discover how tidal exchange between marshes and open water influences primary production and its consumption. Application of this approach could inform Delta management in two ways. First, it would provide a quantitative estimate of how large-scale conversion to agriculture has altered the Delta's capacity to produce food for native biota. Second, it would provide restoration practitioners with a new approach—based on ecosystem function—to evaluate the success of restoration projects and gauge the trajectory of ecological recovery in the Delta region.

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...

Relationships between primary production and irradiance in coral reef algal communities

International Nuclear Information System (INIS)

Anon.

1985-01-01

Shallow water algal turf communities are the major primary producers on coral reefs. High rates of primary production are maintained despite extremely high light intensities and exposure to ultraviolet wavelengths. The relationships between the light intensity and primary production in these assemblages are typical of algae adapted to a high light environment [low α (initial slope), high I/sub k/ (saturating light intensity), and high I/sub c/ (compensation point light intensity)]. Seasonal variations in algal standing crop due to herbivory and daylength result in some characteristic photoadaptive changes in α I/sub k/, and I/sub c/ and changes in Pnet/sub max/ rates (maximum net photosynthetic rate achieved at light saturation) on both a chlorophyll α and an areal basis. Exposure to UV wavelength results in significantly higher respiration rates but no changes in α, Pnet/sub max/, or I/sub k/, when compared with these parameters for the same algal communities incubated at the same light intensities without UV wavelengths. The apparent lack of photoinhibition in these algae allows calculation of the daily integrated production from the P vs. I parameters. This integrated production is highest in July (3.1 +/- 0.2 g C m -2 d -1 ) and is reduced by 30% from this maximum in December (2.1 +/- 0.1 g C m -2 d -1 )

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.

Evaluation of CRUDTRAN code to predict transport of corrosion products and radioactivity in the PWR primary coolant system

International Nuclear Information System (INIS)

Lee, C.B.

2002-01-01

CRUDTRAN code is to predict transport of the corrosion products and their radio-activated nuclides such as cobalt-58 and cobalt-60 in the PWR primary coolant system. In CRUDTRAN code the PWR primary circuit is divided into three principal sections such as the core, the coolant and the steam generator. The main driving force for corrosion product transport in the PWR primary coolant comes from coolant temperature change throughout the system and a subsequent change in corrosion product solubility. As the coolant temperature changes around the PWR primary circuit, saturation status of the corrosion products in the coolant also changes such that under-saturation in steam generator and super-saturation in the core. CRUDTRAN code was evaluated by comparison with the results of the in-reactor loop tests simulating the PWR primary coolant system and PWR plant data. It showed that CRUDTRAN could predict variations of cobalt-58 and cobalt-60 radioactivity with time, plant cycle and coolant chemistry in the PWR plant. (author)

Historical changes of the Mediterranean Sea ecosystem: modelling the role and impact of primary productivity and fisheries changes over time

Science.gov (United States)

Piroddi, Chiara; Coll, Marta; Liquete, Camino; Macias, Diego; Greer, Krista; Buszowski, Joe; Steenbeek, Jeroen; Danovaro, Roberto; Christensen, Villy

2017-03-01

The Mediterranean Sea has been defined “under siege” because of intense pressures from multiple human activities; yet there is still insufficient information on the cumulative impact of these stressors on the ecosystem and its resources. We evaluate how the historical (1950-2011) trends of various ecosystems groups/species have been impacted by changes in primary productivity (PP) combined with fishing pressure. We investigate the whole Mediterranean Sea using a food web modelling approach. Results indicate that both changes in PP and fishing pressure played an important role in driving species dynamics. Yet, PP was the strongest driver upon the Mediterranean Sea ecosystem. This highlights the importance of bottom-up processes in controlling the biological characteristics of the region. We observe a reduction in abundance of important fish species (~34%, including commercial and non-commercial) and top predators (~41%), and increases of the organisms at the bottom of the food web (~23%). Ecological indicators, such as community biomass, trophic levels, catch and diversity indicators, reflect such changes and show overall ecosystem degradation over time. Since climate change and fishing pressure are expected to intensify in the Mediterranean Sea, this study constitutes a baseline reference for stepping forward in assessing the future management of the basin.

Primary Production in the Delta: Then and Now

Directory of Open Access Journals (Sweden)

James E. Cloern

2016-10-01

Full Text Available doi: http://dx.doi.org/10.15447/sfews.2016v14iss3art1To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it is unclear whether this was always the case. Recent analyses from the Historical Ecology Team and Delta Landscapes Project provide quantitative comparisons of the areal extent of 14 habitat types in the modern Delta versus the historical Delta (pre-1850. Here we describe an approach for using these metrics of land use change to: (1 produce the first quantitative estimates of how Delta primary production and the relative contributions from five different producer groups have been altered by large-scale drainage and conversion to agriculture; (2 convert these production estimates into a common currency so the contributions of each producer group reflect their food quality and efficiency of transfer to consumers; and (3 use simple models to discover how tidal exchange between marshes and open water influences primary production and its consumption. Application of this approach could inform Delta management in two ways. First, it would provide a quantitative estimate of how large-scale conversion to agriculture has altered the Delta's capacity to produce food for native biota. Second, it would provide restoration practitioners with a new approach—based on ecosystem function—to evaluate the success of restoration projects and gauge the trajectory of ecological recovery in the Delta region.

Towards 250 m mapping of terrestrial primary productivity over Canada

Science.gov (United States)

Gonsamo, A.; Chen, J. M.

2011-12-01

Terrestrial ecosystems are an important part of the climate and global change systems. Their role in climate change and in the global carbon cycle is yet to be well understood. Dataset from satellite earth observation, coupled with numerical models provide the unique tools for monitoring the spatial and temporal dynamics of territorial carbon cycle. The Boreal Ecosystems Productivity Simulator (BEPS) is a remote sensing based approach to quantifying the terrestrial carbon cycle by that gross and net primary productivity (GPP and NPP) and terrestrial carbon sinks and sources expressed as net ecosystem productivity (NEP). We have currently implemented a scheme to map the GPP, NPP and NEP at 250 m for first time over Canada using BEPS model. This is supplemented by improved mapping of land cover and leaf area index (LAI) at 250 m over Canada from MODIS satellite dataset. The results from BEPS are compared with MODIS GPP product and further evaluated with estimated LAI from various sources to evaluate if the results capture the trend in amount of photosynthetic biomass distributions. Final evaluation will be to validate both BEPS and MODIS primary productivity estimates over the Fluxnet sites over Canada. The primary evaluation indicate that BEPS GPP estimates capture the over storey LAI variations over Canada very well compared to MODIS GPP estimates. There is a large offset of MODIS GPP, over-estimating the lower GPP value compared to BEPS GPP estimates. These variations will further be validated based on the measured values from the Fluxnet tower measurements over Canadian. The high resolution GPP (NPP) products at 250 m will further be used to scale the outputs between different ecosystem productivity models, in our case the Canadian carbon budget model of Canadian forest sector CBM-CFS) and the Integrated Terrestrial Ecosystem Carbon model (InTEC).

Primary production in the Kattegat - past and present

DEFF Research Database (Denmark)

Richardson, K.; Heilmann, Jens

1995-01-01

data collected during the period 1984-1993 are calculated using the method employed in the 1950s. It is concluded that primary production in the Kattegat has increased from less than 100 g C m(-2) y(- 1) to about 200 g C m(-2) y(-1) since the 1950s. This increase is not seen during the winter months...... to be responses to increases in primary production. However, for most areas, there are insufficient data to demonstrate whether or not increases in primary production have actually occurred. In this study, the evidence for increased primary production in the Kattegat is examined by comparing primary production...... measurements from the 1950s and measurements made in the period 1984-1993. The methods employed during the two periods differ considerably. These differences and how they may affect the validity of a comparison of the results from the studies carried out in two periods are addressed. The primary production...

Global patterns in human consumption of net primary production

Science.gov (United States)

Imhoff, Marc L.; Bounoua, Lahouari; Ricketts, Taylor; Loucks, Colby; Harriss, Robert; Lawrence, William T.

2004-06-01

The human population and its consumption profoundly affect the Earth's ecosystems. A particularly compelling measure of humanity's cumulative impact is the fraction of the planet's net primary production that we appropriate for our own use. Net primary production-the net amount of solar energy converted to plant organic matter through photosynthesis-can be measured in units of elemental carbon and represents the primary food energy source for the world's ecosystems. Human appropriation of net primary production, apart from leaving less for other species to use, alters the composition of the atmosphere, levels of biodiversity, energy flows within food webs and the provision of important ecosystem services. Here we present a global map showing the amount of net primary production required by humans and compare it to the total amount generated on the landscape. We then derive a spatial balance sheet of net primary production `supply' and `demand' for the world. We show that human appropriation of net primary production varies spatially from almost zero to many times the local primary production. These analyses reveal the uneven footprint of human consumption and related environmental impacts, indicate the degree to which human populations depend on net primary production `imports' and suggest policy options for slowing future growth of human appropriation of net primary production.

Detection of anthropogenic climate change in satellite records of ocean chlorophyll and productivity

Directory of Open Access Journals (Sweden)

S. A. Henson

2010-02-01

Full Text Available Global climate change is predicted to alter the ocean's biological productivity. But how will we recognise the impacts of climate change on ocean productivity? The most comprehensive information available on its global distribution comes from satellite ocean colour data. Now that over ten years of satellite-derived chlorophyll and productivity data have accumulated, can we begin to detect and attribute climate change-driven trends in productivity? Here we compare recent trends in satellite ocean colour data to longer-term time series from three biogeochemical models (GFDL, IPSL and NCAR. We find that detection of climate change-driven trends in the satellite data is confounded by the relatively short time series and large interannual and decadal variability in productivity. Thus, recent observed changes in chlorophyll, primary production and the size of the oligotrophic gyres cannot be unequivocally attributed to the impact of global climate change. Instead, our analyses suggest that a time series of ~40 years length is needed to distinguish a global warming trend from natural variability. In some regions, notably equatorial regions, detection times are predicted to be shorter (~20–30 years. Analysis of modelled chlorophyll and primary production from 2001–2100 suggests that, on average, the climate change-driven trend will not be unambiguously separable from decadal variability until ~2055. Because the magnitude of natural variability in chlorophyll and primary production is larger than, or similar to, the global warming trend, a consistent, decades-long data record must be established if the impact of climate change on ocean productivity is to be definitively detected.

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.

Evaluation of Organic Proxies for Quantifying Past Primary Productivity

Science.gov (United States)

Raja, M.; Rosell-Melé, A.; Galbraith, E.

2017-12-01

Ocean primary productivity is a key element of the marine carbon cycle. However, its quantitative reconstruction in the past relies on the use of biogeochemical models as the available proxy approaches are qualitative at best. Here, we present an approach that evaluates the use of phytoplanktonic biomarkers (i.e. chlorins and alkenones) as quantitative proxies to reconstruct past changes in marine productivity. We compare biomarkers contents in a global suite of core-top sediments to sea-surface chlorophyll-a abundance estimated by satellites over the last 20 years, and the results are compared to total organic carbon (TOC). We also assess satellite data and detect satellite limitations and biases due to the complexity of optical properties and the actual defined algorithms. Our findings show that sedimentary chlorins can be used to track total sea-surface chlorophyll-a abundance as an indicator for past primary productivity. However, degradation processes restrict the application of this proxy to concentrations below a threshold value (1µg/g). Below this threshold, chlorins are a useful tool to identify reducing conditions when used as part of a multiproxy approach to assess redox sedimentary conditions (e.g. using Re, U). This is based on the link between anoxic/disoxic conditions and the flux of organic matter from the sea-surface to the sediments. We also show that TOC is less accurate than chlorins for estimating sea-surface chlorophyll-a due to the contribution of terrigenous organic matter, and the different degradation pathways of all organic compounds that TOC includes. Alkenones concentration also relates to primary productivity, but they are constrained by different processes in different regions. In conclusion, as lons as specific constraints are taken into account, our study evaluates the use of chlorins and alkenones as quantitative proxies of past primary productivity, with more accuracy than by using TOC.

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

Directory of Open Access Journals (Sweden)

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.

Primary Productivity (PP_Master)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set included primary production for each subregion in the study (Georges Bank, Gulf of Maine, Southern New England, Middle Atlantic Bight) . The data came...

Primary and heterotrophic productivity relate to multikingdom diversity in a hypersaline mat

Energy Technology Data Exchange (ETDEWEB)

Bernstein, Hans C.; Brislawn, Colin J.; Dana, Karl; Flores-Wentz, Tobias; Cory, Alexandra B.; Fansler, Sarah J.; Fredrickson, James K.; Moran, James J.

2017-10-01

Benthic microbial ecosystems are widespread yet knowledge gaps still remain on the relationships between the diversity of species across kingdoms and productivity. Here, we ask two fundamental questions: 1) How does species diversity relate to the rates of primary and heterotrophic productivity? 2) How do diel variations in light-energy inputs influence productivity and microbiome diversity? To answer these questions, microbial mats from a magnesium sulfate hypersaline Lake were used to establish microcosms. Both the number and relatedness between bacterial and eukaryotic taxa in the microbiome were assayed via amplicon based sequencing of 16S and 18S rRNA genes over two diel cycles. These results correlated with biomass productivity obtained from substrate-specific 13C stable isotope incorporation that enabled comparisons between primary and heterotrophic productivity. Both bacterial and eukaryotic species richness and evenness were related only to the rates of 13C labeled glucose and acetate biomass incorporation. Interestingly, measures of these heterotrophic relationships changed from positive and negative correlations depending on carbon derived from glucose and acetate, respectively. Bacterial and eukaryotic diversity of this ecosystem is also controlled, in part, energy constraints imposed by changing irradiance over a diel cycle.

Will Global Change Effect Primary Productivity in Coastal Ecosystems?

Science.gov (United States)

Rothschild, Lynn J.; Peterson, David L. (Technical Monitor)

1997-01-01

Algae are the base of coastal food webs because they provide the source of organic carbon for the remaining members of the community. Thus, the rate that they produce organic carbon to a large extent controls the productivity of the entire ecosystem. Factors that control algal productivity range from the physical (e.g., temperature, light), chemical (e.g., nutrient levels) to the biological (e.g., grazing). Currently, levels of atmospheric carbon dioxide surficial fluxes of ultraviolet radiation are rising. Both of these environmental variables can have a profound effect on algal productivity. Atmospheric carbon dioxide may increase surficial levels of dissolved inorganic carbon. Our laboratory and field studies of algal mats and phytoplankton cultures under ambient and elevated levels of pCO2 show that elevated levels of inorganic carbon can cause an increase in photosynthetic rates. In some cases, this increase will cause an increase in phytoplankton numbers. There may be an increase in the excretion of fixed carbon, which in turn may enhance bacterial productivity. Alternatively, in analogy with studies on the effect of elevated pCO2 on plants, the phytoplankton could change their carbon to nitrogen ratios, which will effect the feeding of the planktonic grazers. The seasonal depletion of stratospheric ozone has resulted in elevated fluxes of UVB radiation superimposed on the normal seasonal variation. Present surface UV fluxes have a significant impact on phytoplankton physiology, including the inhibition of the light and dark reactions of photosynthesis, inhibition of nitrogenase activity, inhibition of heterocyst formation, reduction in motility, increased synthesis of the UV-screening pigment scytonemin, and mutation. After reviewing these issues, recent work in our lab on measuring the effect of UV radiation on phytoplankton in the San Francisco Bay Estuary will be presented.

Shrubland primary production and soil respiration diverge along European climate gradient

DEFF Research Database (Denmark)

Reinsch, Sabine; Koller, Eva; Sowerby, Alwyn

2017-01-01

uncertain. Here we show the responses of ecosystem C to 8-12 years of experimental drought and night-time warming across an aridity gradient spanning seven European shrublands using indices of C assimilation (aboveground net primary production: aNPP) and soil C efflux (soil respiration: Rs). The changes...

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.

Changes in primary productivity and chlorophyll a in response to iron fertilization in the Southern Polar Frontal Zone

OpenAIRE

Gervais, F.; Riebesell, Ulf; Gorbunov, MY

2002-01-01

EisenEx�the second in situ iron enrichment experiment in the Southern Ocean�was performed in the Atlantic sector over 3 weeks in November 2000 with the overarching goal to test the hypothesis that primary productivity in the Southern Ocean is limited by iron availability in the austral spring. Underwater irradiance, chlorophyll a (Chl a), photochemical efficiency, and primary productivity were measured inside and outside of an iron-enriched patch in order to quantify the response of phytoplan...

Variability and Changes in Climate, Phenology, and Gross Primary Production of an Alpine Wetland Ecosystem

Directory of Open Access Journals (Sweden)

Xiaoming Kang

2016-05-01

Full Text Available Quantifying the variability and changes in phenology and gross primary production (GPP of alpine wetlands in the Qinghai–Tibetan Plateau under climate change is essential for assessing carbon (C balance dynamics at regional and global scales. In this study, in situ eddy covariance (EC flux tower observations and remote sensing data were integrated with a modified, satellite-based vegetation photosynthesis model (VPM to investigate the variability in climate change, phenology, and GPP of an alpine wetland ecosystem, located in Zoige, southwestern China. Two-year EC data and remote sensing vegetation indices showed that warmer temperatures corresponded to an earlier start date of the growing season, increased GPP, and ecosystem respiration, and hence increased the C sink strength of the alpine wetlands. Twelve-year long-term simulations (2000–2011 showed that: (1 there were significantly increasing trends for the mean annual enhanced vegetation index (EVI, land surface water index (LSWI, and growing season GPP (R2 ≥ 0.59, p < 0.01 at rates of 0.002, 0.11 year−1 and 16.32 g·C·m−2·year−1, respectively, which was in line with the observed warming trend (R2 = 0.54, p = 0.006; (2 the start and end of the vegetation growing season (SOS and EOS experienced a continuous advancing trend at a rate of 1.61 days·year−1 and a delaying trend at a rate of 1.57 days·year−1 from 2000 to 2011 (p ≤ 0.04, respectively; and (3 with increasing temperature, the advanced SOS and delayed EOS prolonged the wetland’s phenological and photosynthetically active period and, thereby, increased wetland productivity by about 3.7–4.2 g·C·m−2·year−1 per day. Furthermore, our results indicated that warming and the extension of the growing season had positive effects on carbon uptake in this alpine wetland ecosystem.

Primary Productivity of the Cengklik Dam Boyolali

Directory of Open Access Journals (Sweden)

WIRYANTO

2002-01-01

Full Text Available Primary productivity dynamic of the water ecosystem was conducted faster in the last decades. This study was intended to find out the primary productivity of Cengklik dam Boyolali, Central Java to explain the ecosystem dynamic and to lead the maintenance of dam. This study used quantitative methods in completely randomized group design (CRD, and the data was analized by Analysis of Variance (ANAVA. Samples were taken horizontally in four sampling point, respectively in the riparian zone, around of the floating net (“karamba”, in the center of dam water and around of the ex-paddy fields. There were taken vertically in three-depth point in each of the sampling point, respectively 0.5 meter, 1.5 meter, and 2.5 meter. The results showed that the gross primary productivity of the dam was 11.122.500-22.545.600 mgC/m3/days, and the primary productivity differences in each of the point sampling caused by light intensity, nutrient supply, and abundance of the chlorophyll organisms.

Relationship between chlorophyll-a and column primary production

Digital Repository Service at National Institute of Oceanography (India)

Dalal, S.G.; Bhargava, R.M.S.

Relationship between surface chlorophyll a and column primary production has been established to help in estimating the latter more quickly and accurately. The equation derived is Primary Production, y = 0.54 Ln Chl a - 0.6. The relationship...

Global resistance and resilience of primary production following extreme drought are predicted by mean annual precipitation

Science.gov (United States)

Stuart-Haëntjens, E. J.; De Boeck, H. J.; Lemoine, N. P.; Gough, C. M.; Kröel-Dulay, G.; Mänd, P.; Jentsch, A.; Schmidt, I. K.; Bahn, M.; Lloret, F.; Kreyling, J.; Wohlgemuth, T.; Stampfli, A.; Anderegg, W.; Classen, A. T.; Smith, M. D.

2017-12-01

Extreme drought is increasing globally in frequency and intensity, with uncertain consequences for the resistance and resilience of key ecosystem functions, including primary production. Primary production resistance, the capacity of an ecosystem to withstand change in primary production following extreme climate, and resilience, the degree to which primary production recovers, vary among and within ecosystem types, obscuring global patterns of resistance and resilience to extreme drought. Past syntheses on resistance have focused climatic gradients or individual ecosystem types, without assessing interactions between the two. Theory and many empirical studies suggest that forest production is more resistant but less resilient than grassland production to extreme drought, though some empirical studies reveal that these trends are not universal. Here, we conducted a global meta-analysis of sixty-four grassland and forest sites, finding that primary production resistance to extreme drought is predicted by a common continuum of mean annual precipitation (MAP). However, grasslands and forests exhibit divergent production resilience relationships with MAP. We discuss the likely mechanisms underlying the mixed production resistance and resilience patterns of forests and grasslands, including different plant species turnover times and drought adaptive strategies. These findings demonstrate the primary production responses of forests and grasslands to extreme drought are mixed, with far-reaching implications for Earth System Models, ecosystem management, and future studies of extreme drought resistance and resilience.

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.

Drivers of trophic amplification of ocean productivity trends in a changing climate

OpenAIRE

C. A. Stock; J. P. Dunne; J. G. John

2014-01-01

Pronounced projected 21st century trends in regional oceanic net primary production (NPP) raise the prospect of significant redistributions of marine resources. Recent results further suggest that NPP changes may be amplified at higher trophic levels. Here, we elucidate the role of planktonic food web dynamics in driving projected changes in mesozooplankton production (MESOZP) found to be, on average, twice as large as projected changes in...

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.

Mean annual precipitation predicts primary production resistance and resilience to extreme drought.

Science.gov (United States)

Stuart-Haëntjens, Ellen; De Boeck, Hans J; Lemoine, Nathan P; Mänd, Pille; Kröel-Dulay, György; Schmidt, Inger K; Jentsch, Anke; Stampfli, Andreas; Anderegg, William R L; Bahn, Michael; Kreyling, Juergen; Wohlgemuth, Thomas; Lloret, Francisco; Classen, Aimée T; Gough, Christopher M; Smith, Melinda D

2018-04-27

Extreme drought is increasing in frequency and intensity in many regions globally, with uncertain consequences for the resistance and resilience of ecosystem functions, including primary production. Primary production resistance, the capacity to withstand change during extreme drought, and resilience, the degree to which production recovers, vary among and within ecosystem types, obscuring generalized patterns of ecological stability. Theory and many observations suggest forest production is more resistant but less resilient than grassland production to extreme drought; however, studies of production sensitivity to precipitation variability indicate that the processes controlling resistance and resilience may be influenced more by mean annual precipitation (MAP) than ecosystem type. Here, we conducted a global meta-analysis to investigate primary production resistance and resilience to extreme drought in 64 forests and grasslands across a broad MAP gradient. We found resistance to extreme drought was predicted by MAP; however, grasslands (positive) and forests (negative) exhibited opposing resilience relationships with MAP. Our findings indicate that common plant physiological mechanisms may determine grassland and forest resistance to extreme drought, whereas differences among plant residents in turnover time, plant architecture, and drought adaptive strategies likely underlie divergent resilience patterns. The low resistance and resilience of dry grasslands suggests that these ecosystems are the most vulnerable to extreme drought - a vulnerability that is expected to compound as extreme drought frequency increases in the future. Copyright © 2018. Published by Elsevier B.V.

Interannual Variation in Phytoplankton Primary Production at a Global Scale

Science.gov (United States)

Rousseaux, Cecile Severine; Gregg, Watson W.

2013-01-01

We used the NASA Ocean Biogeochemical Model (NOBM) combined with remote sensing data via assimilation to evaluate the contribution of four phytoplankton groups to the total primary production. First, we assessed the contribution of each phytoplankton groups to the total primary production at a global scale for the period 1998-2011. Globally, diatoms contributed the most to the total phytoplankton production ((is)approximately 50%, the equivalent of 20 PgC·y1). Coccolithophores and chlorophytes each contributed approximately 20% ((is) approximately 7 PgC·y1) of the total primary production and cyanobacteria represented about 10% ((is) approximately 4 PgC·y1) of the total primary production. Primary production by diatoms was highest in the high latitudes ((is) greater than 40 deg) and in major upwelling systems (Equatorial Pacific and Benguela system). We then assessed interannual variability of this group-specific primary production over the period 1998-2011. Globally the annual relative contribution of each phytoplankton groups to the total primary production varied by maximum 4% (1-2 PgC·y1). We assessed the effects of climate variability on group-specific primary production using global (i.e., Multivariate El Niño Index, MEI) and "regional" climate indices (e.g., Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO)). Most interannual variability occurred in the Equatorial Pacific and was associated with climate variability as indicated by significant correlation (p (is) less than 0.05) between the MEI and the group-specific primary production from all groups except coccolithophores. In the Atlantic, climate variability as indicated by NAO was significantly correlated to the primary production of 2 out of the 4 groups in the North Central Atlantic (diatoms/cyanobacteria) and in the North Atlantic (chlorophytes and coccolithophores). We found that climate variability as indicated by SAM had only a limited effect

Primary production of tropical marine ecosystems

Digital Repository Service at National Institute of Oceanography (India)

Bhattathiri, P.M.A.

Among tropical marine ecosystems estuaries are one of the highly productive areas and act as a nursery to large number of organisms. The primary production in most of the estuaries is less during the monsoon period. Post-monsoon period shows...

Valuing ecosystem services. A shadow price for net primary production

International Nuclear Information System (INIS)

Richmond, Amy; Kaufmann, Robert K.; Myneni, Ranga B.

2007-01-01

We analyze the contribution of ecosystem services to GDP and use this contribution to calculate an empirical price for ecosystem services. Net primary production is used as a proxy for ecosystem services and, along with capital and labor, is used to estimate a Cobb Douglas production function from an international panel. A positive output elasticity for net primary production probably measures both marketed and nonmarketed contributions of ecosystems services. The production function is used to calculate the marginal product of net primary production, which is the shadow price for ecosystem services. The shadow price generally is greatest for developed nations, which have larger technical scalars and use less net primary production per unit output. The rate of technical substitution indicates that the quantity of capital needed to replace a unit of net primary production tends to increase with economic development, and this rate of replacement may ultimately constrain economic growth. (author)

Altered primary production during mass-extinction events

NARCIS (Netherlands)

van de Schootbrugge, B.; Gollner, S.

2013-01-01

The Big Five mass-extinction events are characterized by dramatic changes in primary producers. Initial disturbance to primary producers is usually followed by a succession of pioneers that represent qualitative and quantitative changes in standing crops of land plants and/or phytoplankton. On land,

HANPP Collection: Global Patterns in Net Primary Productivity (NPP)

Data.gov (United States)

National Aeronautics and Space Administration — The Global Patterns in Net Primary Productivity (NPP) portion of the Human Appropriation of Net Primary Productivity (HANPP) Collection maps the net amount of solar...

Dissolved organic carbon concentration controls benthic primary production: results from in situ chambers in north-temperate lakes

Science.gov (United States)

Godwin, Sean C.; Jones, Stuart E.; Weidel, Brian C.; Solomon, Christopher T.

2014-01-01

We evaluated several potential drivers of primary production by benthic algae (periphyton) in north-temperate lakes. We used continuous dissolved oxygen measurements from in situ benthic chambers to quantify primary production by periphyton at multiple depths across 11 lakes encompassing a broad range of dissolved organic carbon (DOC) and total phosphorous (TP) concentrations. Light-use efficiency (primary production per unit incident light) was inversely related to average light availability (% of surface light) in 7 of the 11 study lakes, indicating that benthic algal assemblages exhibit photoadaptation, likely through physiological or compositional changes. DOC alone explained 86% of the variability in log-transformed whole-lake benthic production rates. TP was not an important driver of benthic production via its effects on nutrient and light availability. This result is contrary to studies in other systems, but may be common in relatively pristine north-temperate lakes. Our simple empirical model may allow for the prediction of whole-lake benthic primary production from easily obtained measurements of DOC concentration.

Leading Change in the Primary Science Curriculum

Science.gov (United States)

Waller, Nicky; Baker, Chris

2014-01-01

Nicky Waller and Chris Baker believe that change can be a good thing and explain how their training has helped others to adjust to the new science curriculum. In September 2013, teachers across England received the definitive version of the new primary curriculum "Leading Change in the Primary Science Curriculum." This course aimed to…

Comparison between remote sensing and a dynamic vegetation model for estimating terrestrial primary production of Africa.

Science.gov (United States)

Ardö, Jonas

2015-12-01

Africa is an important part of the global carbon cycle. It is also a continent facing potential problems due to increasing resource demand in combination with climate change-induced changes in resource supply. Quantifying the pools and fluxes constituting the terrestrial African carbon cycle is a challenge, because of uncertainties in meteorological driver data, lack of validation data, and potentially uncertain representation of important processes in major ecosystems. In this paper, terrestrial primary production estimates derived from remote sensing and a dynamic vegetation model are compared and quantified for major African land cover types. Continental gross primary production estimates derived from remote sensing were higher than corresponding estimates derived from a dynamic vegetation model. However, estimates of continental net primary production from remote sensing were lower than corresponding estimates from the dynamic vegetation model. Variation was found among land cover classes, and the largest differences in gross primary production were found in the evergreen broadleaf forest. Average carbon use efficiency (NPP/GPP) was 0.58 for the vegetation model and 0.46 for the remote sensing method. Validation versus in situ data of aboveground net primary production revealed significant positive relationships for both methods. A combination of the remote sensing method with the dynamic vegetation model did not strongly affect this relationship. Observed significant differences in estimated vegetation productivity may have several causes, including model design and temperature sensitivity. Differences in carbon use efficiency reflect underlying model assumptions. Integrating the realistic process representation of dynamic vegetation models with the high resolution observational strength of remote sensing may support realistic estimation of components of the carbon cycle and enhance resource monitoring, providing suitable validation data is available.

Climate change impacts on southern Ross Sea phytoplankton composition, productivity, and export

Science.gov (United States)

Kaufman, Daniel E.; Friedrichs, Marjorie A. M.; Smith, Walker O.; Hofmann, Eileen E.; Dinniman, Michael S.; Hemmings, John C. P.

2017-03-01

The Ross Sea, a highly productive region of the Southern Ocean, is expected to experience warming during the next century along with reduced summer sea ice concentrations and shallower mixed layers. This study investigates how these climatic changes may alter phytoplankton assemblage composition, primary productivity, and export. Glider measurements are used to force a one-dimensional biogeochemical model, which includes diatoms and both solitary and colonial forms of Phaeocystis antarctica. Model performance is evaluated with glider observations, and experiments are conducted using projections of physical drivers for mid-21st and late-21st century. These scenarios reveal a 5% increase in primary productivity by midcentury and 14% by late-century and a proportional increase in carbon export, which remains approximately 18% of primary production. In addition, scenario results indicate diatom biomass increases while P. antarctica biomass decreases in the first half of the 21st century. In the second half of the century, diatom biomass remains relatively constant and P. antarctica biomass increases. Additional scenarios examining the independent contributions of expected future changes (temperature, mixed layer depth, irradiance, and surface iron inputs from melting ice) demonstrate that earlier availability of low light due to reduction of sea ice early in the growing season is the primary driver of productivity increases over the next century; shallower mixed layer depths additionally contribute to changes of assemblage composition and export. This study further demonstrates how glider data can be effectively used to facilitate model development and simulation, and inform interpretation of biogeochemical observations in the context of climate change.Plain Language SummaryUnderstanding how the global ocean responds to climate change requires knowing the natural behavior of individual regions and anticipating how future changes will affect each region differently. It

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

Method for the production of primary amines

NARCIS (Netherlands)

Baldenius, Kai-Uwe; Ditrich, Klaus; Breurer, Michael; Navickas, Vaidotas; Janssen, Dick; Crismaru, Ciprian; Bartsch, Sebastian

2014-01-01

The present invention relates to a novel enzymatically catalyzed method for the production of aliphatic primary amines, which method comprises the enzymatic oxidation of a primary aliphatic alcohol catalyzed by an alcohol dehydrogenase, amination of the resulting oxocompound catalyzed by a

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

Variation of phytoplankton biomass and primary production in Daya Bay during spring and summer

International Nuclear Information System (INIS)

Song Xingyu; Huang Liangmin; Zhang Jianlin; Huang, Xiaoping; Zhang Junbin; Yin Jianqiang; Tan Yehui; Liu Sheng

2004-01-01

Environmental factors, phytoplankton biomass (Chl a) and primary production of two water areas in Daya Bay (Dapeng'ao Bay and Aotou Bay) were investigated during the transition period from spring to summer. Chl a ranged from 3.20 to 13.62 and 13.43 to 26.49 mg m -3 in Dapeng'ao Bay and Aotou Bay respectively, if data obtained during red tides are excluded. Primary production varied between 239.7 and 1001.4 mgC m -2 d -1 in Dapeng'ao Bay. The regional distribution of Chl a and primary production were mostly consistent from spring to summer in both bays. Seasonal transition characters have been found in Daya Bay from spring to summer, including high values of DO, nitrate and silicate. Size structures of phytoplankton and its primary production do not change very much from spring to summer, with micro-phytoplankton dominating and contributing about 50% of the whole. In Daya Bay, phytoplankton is limited by nitrogen in spring, and by phosphate in summer. Artificial impacts are evident from high temperature effluent from nuclear power stations, aquaculture and sewage. During the investigation, a red tide occurred in Aotou Bay, with a maximum Chl a of 103.23 mg m -3 at surface and primary production of 2721.9 mgC m -2 d -1 in the red tide center. Raised water temperature and nutrient supply from land-sources help to stimulate annual red tides

Inorganic carbon addition stimulates snow algae primary productivity

Science.gov (United States)

Hamilton, T. L.; Havig, J. R.

2017-12-01

Earth has experienced glacial/interglacial oscillations throughout its history. Today over 15 million square kilometers (5.8 million square miles) of Earth's land surface is covered in ice including glaciers, ice caps, and the ice sheets of Greenland and Antarctica, most of which are retreating as a consequence of increased atmospheric CO2. Glaciers are teeming with life and supraglacial snow and ice surfaces are often red due to blooms of photoautotrophic algae. Recent evidence suggests the red pigmentation, secondary carotenoids produced in part to thrive under high irradiation, lowers albedo and accelerates melt. However, there are relatively few studies that report the productivity of snow algae communities and the parameters that constrain their growth on snow and ice surfaces. Here, we demonstrate that snow algae primary productivity can be stimulated by the addition of inorganic carbon. We found an increase in light-dependent carbon assimilation in snow algae microcosms amended with increasing amounts of inorganic carbon. Our snow algae communities were dominated by typical cosmopolitan snow algae species recovered from Alpine and Arctic environments. The climate feedbacks necessary to enter and exit glacial/interglacial oscillations are poorly understood. Evidence and models agree that global Snowball events are accompanied by changes in atmospheric CO2 with increasing CO2 necessary for entering periods of interglacial time. Our results demonstrate a positive feedback between increased CO2 and snow algal productivity and presumably growth. With the recent call for bio-albedo effects to be considered in climate models, our results underscore the need for robust climate models to include feedbacks between supraglacial primary productivity, albedo, and atmospheric CO2.

Long-term changes in primary production and mineralization of organic matter in the Neva Estuary (Baltic Sea)

Science.gov (United States)

Golubkov, Sergey; Golubkov, Mikhail; Tiunov, Alexei; Nikulina, Vera

2017-07-01

The Neva Estuary situated in the eastern part of the Gulf of Finland is one of the largest estuaries of the Baltic Sea. At present, heavy nutrient and organic matter loading, mainly from the Neva River and point sources in the upper estuary are the most serious environmental problem for the Neva Estuary and adjacent parts of the eastern Gulf of Finland. Long-term studies of mid-summer primary production and mineralization of organic matter were conducted in upper and middle parts of the Neva Estuary. A considerable increase of production and biomass of phytoplankton was observed in the middle part of the estuary during the last decades mainly due to an increase in biomass of cyanobacteria. However, they are mostly concentrated in the upper water layers and only a small part of them reached the near bottom water layers and may be used as a food by zoobenthos. The mineralization of organic matter in the water column was twice higher than primary production that indicates the importance of allochthonous organic matter in the carbon budget of the both parts of the estuary. The carbon isotope signature of seston and most of the zoobenthic species in the upper part of the estuary was close to the signature of allochthonous carbon leaking from watershed (- 27‰). Higher values of δ13C of seston in the upper mix layer of the Middle estuary indicate intensive primary production in mid-summer. The carbon isotopic signature of zoobenthos in this part of the estuary was also in general lower than in the Neva Bay reflected higher importance of autochthonous organic matter in food webs of the estuary.

Reforming primary healthcare: from public policy to organizational change.

Science.gov (United States)

Gilbert, Frédéric; Denis, Jean-Louis; Lamothe, Lise; Beaulieu, Marie-Dominique; D'amour, Danielle; Goudreau, Johanne

2015-01-01

Governments everywhere are implementing reform to improve primary care. However, the existence of a high degree of professional autonomy makes large-scale change difficult to achieve. The purpose of this paper is to elucidate the change dynamics and the involvement of professionals in a primary healthcare reform initiative carried out in the Canadian province of Quebec. An empirical approach was used to investigate change processes from the inception of a public policy to the execution of changes in professional practices. The data were analysed from a multi-level, combined contextualist-processual perspective. Results are based on a longitudinal multiple-case study of five family medicine groups, which was informed by over 100 interviews, questionnaires, and documentary analysis. The results illustrate the multiple processes observed with the introduction of planned large-scale change in primary care services. The analysis of change content revealed that similar post-change states concealed variations between groups in the scale of their respective changes. The analysis also demonstrated more precisely how change evolved through the introduction of "intermediate change" and how cycles of prescribed and emergent mechanisms distinctively drove change process and change content, from the emergence of the public policy to the change in primary care service delivery. This research was conducted among a limited number of early policy adopters. However, given the international interest in turning to the medical profession to improve primary care, the results offer avenues for both policy development and implementation. The findings offer practical insights for those studying and managing large-scale transformations. They provide a better understanding of how deliberate reforms coexist with professional autonomy through an intertwining of change content and processes. This research is one of few studies to examine a primary care reform from emergence to implementation

Cultivar-Specific Changes in Primary and Secondary Metabolites in Pak Choi (Brassica Rapa, Chinensis Group by Methyl Jasmonate

Directory of Open Access Journals (Sweden)

Moo Jung Kim

2017-05-01

Full Text Available Glucosinolates, their hydrolysis products and primary metabolites were analyzed in five pak choi cultivars to determine the effect of methyl jasmonate (MeJA on metabolite flux from primary metabolites to glucosinolates and their hydrolysis products. Among detected glucosinolates (total 14 glucosinolates; 9 aliphatic, 4 indole and 1 aromatic glucosinolates, indole glucosinolate concentrations (153–229% and their hydrolysis products increased with MeJA treatment. Changes in the total isothiocyanates by MeJA were associated with epithiospecifier protein activity estimated as nitrile formation. Goitrin, a goitrogenic compound, significantly decreased by MeJA treatment in all cultivars. Changes in glucosinolates, especially aliphatic, significantly differed among cultivars. Primary metabolites including amino acids, organic acids and sugars also changed with MeJA treatment in a cultivar-specific manner. A decreased sugar level suggests that they might be a carbon source for secondary metabolite biosynthesis in MeJA-treated pak choi. The result of the present study suggests that MeJA can be an effective agent to elevate indole glucosinolates and their hydrolysis products and to reduce a goitrogenic compound in pak choi. The total glucosinolate concentration was the highest in “Chinese cabbage” in the control group (32.5 µmol/g DW, but indole glucosinolates increased the greatest in “Asian” when treated with MeJA.

Interannual Variation in Phytoplankton Class-Specific Primary Production at a Global Scale

Science.gov (United States)

Rousseaux, Cecile Severine; Gregg, Watson W.

2014-01-01

We used the NASA Ocean Biogeochemical Model (NOBM) combined with remote sensing data via assimilation to evaluate the contribution of 4 phytoplankton groups to the total primary production. First we assessed the contribution of each phytoplankton groups to the total primary production at a global scale for the period 1998-2011. Globally, diatoms were the group that contributed the most to the total phytoplankton production (50, the equivalent of 20 PgC y-1. Coccolithophores and chlorophytes each contributed to 20 (7 PgC y-1 of the total primary production and cyanobacteria represented about 10 (4 PgC y(sub-1) of the total primary production. Primary production by diatoms was highest in high latitude (45) and in major upwelling systems (Equatorial Pacific and Benguela system). We then assessed interannual variability of this group-specific primary production over the period 1998-2011. Globally the annual relative contribution of each phytoplankton groups to the total primary production varied by maximum 4 (1-2 PgC y-1. We assessed the effects of climate variability on the class-specific primary production using global (i.e. Multivariate El Nio Index, MEI) and regional climate indices (e.g. Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO)). Most interannual variability occurred in the Equatorial Pacific and was associated with climate variability as indicated by significant correlation (p 0.05) between the MEI and the class-specific primary production from all groups except coccolithophores. In the Atlantic, climate variability as indicated by NAO was significantly correlated to the primary production of 2 out of the 4 groups in the North Central Atlantic (diatomscyanobacteria) and in the North Atlantic (chlorophytes and coccolithophores). We found that climate variability as indicated by SAM had only a limited effect on the class-specific primary production in the Southern Ocean. These results provide a modeling and

Remotely Sensed Northern Vegetation Response to Changing Climate: Growing Season and Productivity Perspective

Science.gov (United States)

Ganguly, S.; Park, Taejin; Choi, Sungho; Bi, Jian; Knyazikhin, Yuri; Myneni, Ranga

2016-01-01

Vegetation growing season and maximum photosynthetic state determine spatiotemporal variability of seasonal total gross primary productivity of vegetation. Recent warming induced impacts accelerate shifts on growing season and physiological status over Northern vegetated land. Thus, understanding and quantifying these changes are very important. Here, we first investigate how vegetation growing season and maximum photosynthesis state are evolved and how such components contribute on inter-annual variation of seasonal total gross primary productivity. Furthermore, seasonally different response of northern vegetation to changing temperature and water availability is also investigated. We utilized both long-term remotely sensed data to extract larger scale growing season metrics (growing season start, end and duration) and productivity (i.e., growing season summed vegetation index, GSSVI) for answering these questions. We find that regionally diverged growing season shift and maximum photosynthetic state contribute differently characterized productivity inter-annual variability and trend. Also seasonally different response of vegetation gives different view of spatially varying interaction between vegetation and climate. These results highlight spatially and temporally varying vegetation dynamics and are reflective of biome-specific responses of northern vegetation to changing climate.

Modelling size-fractionated primary production in the Atlantic Ocean from remote sensing

Science.gov (United States)

Brewin, Robert J. W.; Tilstone, Gavin H.; Jackson, Thomas; Cain, Terry; Miller, Peter I.; Lange, Priscila K.; Misra, Ankita; Airs, Ruth L.

2017-11-01

Marine primary production influences the transfer of carbon dioxide between the ocean and atmosphere, and the availability of energy for the pelagic food web. Both the rate and the fate of organic carbon from primary production are dependent on phytoplankton size. A key aim of the Atlantic Meridional Transect (AMT) programme has been to quantify biological carbon cycling in the Atlantic Ocean and measurements of total primary production have been routinely made on AMT cruises, as well as additional measurements of size-fractionated primary production on some cruises. Measurements of total primary production collected on the AMT have been used to evaluate remote-sensing techniques capable of producing basin-scale estimates of primary production. Though models exist to estimate size-fractionated primary production from satellite data, these have not been well validated in the Atlantic Ocean, and have been parameterised using measurements of phytoplankton pigments rather than direct measurements of phytoplankton size structure. Here, we re-tune a remote-sensing primary production model to estimate production in three size fractions of phytoplankton (10 μm) in the Atlantic Ocean, using measurements of size-fractionated chlorophyll and size-fractionated photosynthesis-irradiance experiments conducted on AMT 22 and 23 using sequential filtration-based methods. The performance of the remote-sensing technique was evaluated using: (i) independent estimates of size-fractionated primary production collected on a number of AMT cruises using 14C on-deck incubation experiments and (ii) Monte Carlo simulations. Considering uncertainty in the satellite inputs and model parameters, we estimate an average model error of between 0.27 and 0.63 for log10-transformed size-fractionated production, with lower errors for the small size class (10 μm), and errors generally higher in oligotrophic waters. Application to satellite data in 2007 suggests the contribution of cells 2 μm to total

Primary production in the Bay of Bengal during August 1977

Digital Repository Service at National Institute of Oceanography (India)

Devassy, V.P.; Bhattathiri, P.M.A.; Radhakrishna, K.

Primary production, chlorophyll @ia@@, phaeophytin, phytoplankton and particulate organic carbon (POC) were studied at 14 stations in the Bay of Bengal during August 1977. Column primary production, chlorophyll @ia@@, and phaeopigments varied from 0...

Connectedness of land use, nutrients, primary production, and fish assemblages in oxbow lakes

Science.gov (United States)

Miranda, Leandro E.; Andrews, Caroline S.; Kroger, Robert

2013-01-01

We explored the strength of connectedness among hierarchical system components associated with oxbow lakes in the alluvial valley of the Lower Mississippi River. Specifically, we examined the degree of canonical correlation between land use (agriculture and forests), lake morphometry (depth and size), nutrients (total nitrogen and total phosphorus), primary production (chlorophyll-a), and various fish assemblage descriptors. Watershed (p < 0.01) and riparian (p = 0.02) land use, and lake depth (p = 0.05) but not size (p = 0.28), were associated with nutrient concentrations. In turn, nutrients were associated with primary production (p < 0.01), and primary production was associated with sunfish (Centrarchidae) assemblages (p < 0.01) and fish biodiversity (p = 0.08), but not with those of other taxa and functional guilds. Multiple chemical and biological components of oxbow lake ecosystems are connected to landscape characteristics such as land use and lake depth. Therefore, a top-down hierarchical approach can be useful in developing management and conservation plans for oxbow lakes in a region impacted by widespread landscape changes due to agriculture.

Quantifying Impacts of Land-Use/Cover Change on Urban Vegetation Gross Primary Production: A Case Study of Wuhan, China

Directory of Open Access Journals (Sweden)

Shishi Liu

2018-03-01

Full Text Available This study quantified the impacts of land-use/cover change (LUCC on gross primary production (GPP during 2000–2013 in a typical densely urbanized Chinese city, Wuhan. GPP was estimated at 30-m spatial resolution using annual land cover maps, meteorological data of the baseline year, and the normalized difference vegetation index (NDVI, which was generated with the spatial and temporal adaptive reflectance fusion model (STARFM based on Landsat and MODIS images. The results showed that approximately 309.95 Gg C was lost over 13 years, which was mainly due to the conversion from cropland to built-up areas. The interannual variation of GPP was affected by the change of vegetation composition, especially the increasing relative fraction of forests. The loss of GPP due to the conversion from forest to cropland fluctuated through the study period, but showed a sharp decrease in 2007 and 2008. The gain of GPP due to the conversion from cropland to forest was low between 2001 and 2009, but increased dramatically between 2009 and 2013. The change rate map showed an increasing trend along the highways, and a decreasing trend around the metropolitan area and lakes. The results indicated that carbon consequences should be considered before land management policies are put forth.

Methylmercury bioaccumulation in stream food webs declines with increasing primary production

Science.gov (United States)

Walters, David; D.F. Raikow,; C.R. Hammerschmidt,; M.G. Mehling,; A. Kovach,; J.T. Oris,

2015-01-01

Opposing hypotheses posit that increasing primary productivity should result in either greater or lesser contaminant accumulation in stream food webs. We conducted an experiment to evaluate primary productivity effects on MeHg accumulation in stream consumers. We varied light for 16 artificial streams creating a productivity gradient (oxygen production =0.048–0.71 mg O2 L–1 d–1) among streams. Two-level food webs were established consisting of phytoplankton/filter feeding clam, periphyton/grazing snail, and leaves/shredding amphipod (Hyalella azteca). Phytoplankton and periphyton biomass, along with MeHg removal from the water column, increased significantly with productivity, but MeHg concentrations in these primary producers declined. Methylmercury concentrations in clams and snails also declined with productivity, and consumer concentrations were strongly correlated with MeHg concentrations in primary producers. Heterotroph biomass on leaves, MeHg in leaves, and MeHg in Hyalella were unrelated to stream productivity. Our results support the hypothesis that contaminant bioaccumulation declines with stream primary production via the mechanism of bloom dilution (MeHg burden per cell decreases in algal blooms), extending patterns of contaminant accumulation documented in lakes to lotic systems.

On the role of tides and strong wind events in promoting summer primary production in the Barents Sea

Science.gov (United States)

Le Fouest, Vincent; Postlethwaite, Clare; Morales Maqueda, Miguel Angel; Bélanger, Simon; Babin, Marcel

2011-11-01

Tides and wind-driven mixing play a major role in promoting post-bloom productivity in subarctic shelf seas. Whether this is also true in the high Arctic remains unknown. This question is particularly relevant in a context of increasing Arctic Ocean stratification in response to global climatic change. We have used a three-dimensional ocean-sea ice-plankton ecosystem model to assess the contribution of tides and strong wind events to summer (June-August 2001) primary production in the Barents Sea. Tides are responsible for 20% (60% locally) of the post-bloom primary production above Svalbard Bank and east of the Kola Peninsula. By contrast, more than 9% of the primary production is due to winds faster than 8 m s -1 in the central Barents Sea. Locally, this contribution reaches 25%. In the marginal ice zone, both tides and wind events have only a limited effect on primary production (central Barents Sea), respectively. When integrated over all Barents Sea sub-regions, tides and strong wind events account, respectively, for 6.8% (1.55 Tg C; 1 Tg C=10 12 g C) and 4.1% (0.93 Tg C) of the post-bloom primary production (22.6 Tg C). To put this in context, this contribution to summer primary production is equivalent to the spring bloom integrated over the Svalbard area. Tides and winds are significant drivers of summer plankton productivity in the Barents Sea.

A 10-days heatwave around flowering superimposed on climate change conditions significantly affects production of 22 barley accessions

DEFF Research Database (Denmark)

Ingvordsen, Cathrine Heinz; Lyngkjær, Michael F.; Peltonen-Sainio, Pirjo

2015-01-01

Extreme climate events as heatwaves, floods and storms cause acute changes in season variability influencing primary production and are very likely to increase in magnitude and/or frequency (IPCC, AR5, WGI). In the present study 22 primarily Nordic barley accessions were grown in four basic clima...... climate change conditions on numerous accessions in order to select appropriate genotypes for breeding future cultivars that can secure the primary production....

Views of Primary School Administrators on Change in Schools and Change Management Practices

Science.gov (United States)

Hosgörür, Vural

2016-01-01

The aim of this study is to determine the opinions of primary school administrators about change, and to reveal which strategies they use to manage change in schools. This is a qualitative study conducted in 2014 academic year in Mugla province. Research data were collected from primary school administrators through semi-structured interviews.…

The 2010 spring drought reduced primary productivity in southwestern China

International Nuclear Information System (INIS)

Zhang Li; Li Jing; Xiao Jingfeng; Wang Kun; Lei Liping; Guo Huadong

2012-01-01

Many parts of the world experience frequent and severe droughts. Summer drought can significantly reduce primary productivity and carbon sequestration capacity. The impacts of spring droughts, however, have received much less attention. A severe and sustained spring drought occurred in southwestern China in 2010. Here we examine the influence of this spring drought on the primary productivity of terrestrial ecosystems using data on climate, vegetation greenness and productivity. We first assess the spatial extent, duration and severity of the drought using precipitation data and the Palmer drought severity index. We then examine the impacts of the drought on terrestrial ecosystems using satellite data for the period 2000–2010. Our results show that the spring drought substantially reduced the enhanced vegetation index (EVI) and gross primary productivity (GPP) during spring 2010 (March–May). Both EVI and GPP also substantially declined in the summer and did not fully recover from the drought stress until August. The drought reduced regional annual GPP and net primary productivity (NPP) in 2010 by 65 and 46 Tg C yr −1 , respectively. Both annual GPP and NPP in 2010 were the lowest over the period 2000–2010. The negative effects of the drought on annual primary productivity were partly offset by the remarkably high productivity in August and September caused by the exceptionally wet conditions in late summer and early fall and the farming practices adopted to mitigate drought effects. Our results show that, like summer droughts, spring droughts can also have significant impacts on vegetation productivity and terrestrial carbon cycling. (letter)

Seasonal patterns in phytoplankton photosynthetic parameters and primary production at a coastal NW Mediterranean site

KAUST Repository

Gasol, Josep M.

2016-10-11

We carried out monthly photosynthesis-irradiance (P-E) experiments with the 14C-method for 12 years (2003–2014) to determine the photosynthetic parameters and primary production of surface phytoplankton in the Blanes Bay Microbial Observatory, a coastal sampling station in the NW Mediterranean Sea. Our goal was to obtain seasonal trends and to establish the basis for detecting future changes of primary production in this oligotrophic area. The maximal photosynthetic rate PBmax ranged 30-fold (0.5-15 mg C mg Chl a–1 h–1), averaged 3.7 mg C mg Chl a–1 h–1 (±0.25 SE) and was highest in August and lowest in April and December. We only observed photoinhibition twice. The initial or light-limited slope of the P-E relationship, αB, was low, averaging 0.007 mg C mg Chl a–1 h–1 (μmol photons m–2 s–1)–1 (±0.001 SE, range 0.001-0.045) and showed the lowest values in spring (April-June). The light saturation parameter or saturation irradiance, EK, averaged 711 μmol photons m–2 s–1 (±58.4 SE) and tended to be higher in spring and lower in winter. Phytoplankton assemblages were typically dominated by picoeukaryotes in early winter, diatoms in late autumn and late winter, dinoflagellates in spring and cyanobacteria in summer. Total particulate primary production averaged 1.45 mg C m–3 h–1 (±0.13 SE) with highest values in winter (up to 8.50 mg C m–3 h–1) and lowest values in summer (summer average, 0.30 mg C m–3 h–1), while chlorophyll-specific primary production averaged 2.49 mg C mg Chl a–1 h–1 (±0.19, SE) and peaked in summer (up to 12.0 mg C mg Chl a–1 h–1 in August). 14C-determined phytoplankton growth rates varied between ca. 0.3 d–1 in winter and 0.5 d–1 in summer and were within 60-80% of the maximal rates of growth, based on PBmax. Chlorophyll a was a good predictor of primary production only in the winter and autumn. Seasonality appeared to explain most of the variability in the studied variables, while

Seasonal patterns in phytoplankton photosynthetic parameters and primary production at a coastal NW Mediterranean site

Directory of Open Access Journals (Sweden)

Josep M. Gasol

2016-09-01

Full Text Available We carried out monthly photosynthesis-irradiance (P-E experiments with the 14C-method for 12 years (2003–2014 to determine the photosynthetic parameters and primary production of surface phytoplankton in the Blanes Bay Microbial Observatory, a coastal sampling station in the NW Mediterranean Sea. Our goal was to obtain seasonal trends and to establish the basis for detecting future changes of primary production in this oligotrophic area. The maximal photosynthetic rate PBmax ranged 30-fold (0.5-15 mg C mg Chl a–1 h–1, averaged 3.7 mg C mg Chl a–1 h–1 (±0.25 SE and was highest in August and lowest in April and December. We only observed photoinhibition twice. The initial or light-limited slope of the P-E relationship, αB, was low, averaging 0.007 mg C mg Chl a–1 h–1 (μmol photons m–2 s–1–1 (±0.001 SE, range 0.001-0.045 and showed the lowest values in spring (April-June. The light saturation parameter or saturation irradiance, EK, averaged 711 μmol photons m–2 s–1 (± 58.4 SE and tended to be higher in spring and lower in winter. Phytoplankton assemblages were typically dominated by picoeukaryotes in early winter, diatoms in late autumn and late winter, dinoflagellates in spring and cyanobacteria in summer. Total particulate primary production averaged 1.45 mg C m-3 h–1 (±0.13 SE with highest values in winter (up to 8.50 mg C m-3 h–1 and lowest values in summer (summer average, 0.30 mg C m-3 h–1, while chlorophyll-specific primary production averaged 2.49 mg C mg Chl a–1 h–1 (±0.19, SE and peaked in summer (up to 12.0 mg C mg Chl a–1 h–1 in August. 14C-determined phytoplankton growth rates varied between ca. 0.3 d–1 in winter and 0.5 d–1 in summer and were within 60-80% of the maximal rates of growth, based on PBmax. Chlorophyll a was a good predictor of primary production only in the winter and autumn. Seasonality appeared to explain most of the variability in the studied variables, while

Sources of energy productivity change in China during 1997–2012: A decomposition analysis based on the Luenberger productivity indicator

International Nuclear Information System (INIS)

Wang, Ke; Wei, Yi-Ming

2016-01-01

Given that different energy inputs play different roles in production and that energy policy decision making requires an evaluation of productivity change in individual energy input to provide insight into the scope for improvement of the utilization of specific energy input, this study develops, based on the Luenberger productivity indicator and data envelopment analysis models, an aggregated specific energy productivity indicator combining the individual energy input productivity indicators that account for the contributions of each specific energy input toward energy productivity change. In addition, these indicators can be further decomposed into four factors: pure efficiency change, scale efficiency change, pure technology change, and scale of technology change. These decompositions enable a determination of which specific energy input is the driving force of energy productivity change and which of the four factors is the primary contributor of energy productivity change. An empirical analysis of China's energy productivity change over the period 1997–2012 indicates that (i) China's energy productivity growth may be overestimated if energy consumption structure is omitted; (ii) in regard to the contribution of specific energy input toward energy productivity growth, oil and electricity show positive contributions, but coal and natural gas show negative contributions; (iii) energy-specific productivity changes are mainly caused by technical changes rather than efficiency changes; and (iv) the Porter Hypothesis is partially supported in China that carbon emissions control regulations may lead to energy productivity growth. - Highlights: • An energy input specific Luenberger productivity indicator is proposed. • It enables to examine the contribution of specific energy input productivity change. • It can be decomposed for identifying pure and scale efficiency changes, as well as pure and scale technical changes. • China's energy productivity growth may

Catastrophic shifts in the aquatic primary production revealed by a small low-flow section of tropical downstream after dredging.

Science.gov (United States)

Marotta, H; Enrich-Prast, A

2015-11-01

Dredging is a catastrophic disturbance that directly affects key biological processes in aquatic ecosystems, especially in those small and shallow. In the tropics, metabolic responses could still be enhanced by the high temperatures and solar incidence. Here, we assessed changes in the aquatic primary production along a small section of low-flow tropical downstream (Imboassica Stream, Brazil) after dredging. Our results suggested that these ecosystems may show catastrophic shifts between net heterotrophy and autotrophy in waters based on three short-term stages following the dredging: (I) a strongly heterotrophic net primary production -NPP- coupled to an intense respiration -R- likely supported by high resuspended organic sediments and nutrients from the bottom; (II) a strongly autotrophic NPP coupled to an intense gross primary production -GPP- favored by the high nutrient levels and low solar light attenuation from suspended solids or aquatic macrophytes; and (III) a NPP near to the equilibrium coupled to low GPP and R rates following, respectively, the shading by aquatic macrophytes and high particulate sedimentation. In conclusion, changes in aquatic primary production could be an important threshold for controlling drastic shifts in the organic matter cycling and the subsequent silting up of small tropical streams after dredging events.

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...

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.

Changes in forest productivity across Alaska consistent with biome shift.

Science.gov (United States)

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

2011-04-01

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

Clinical productivity of primary care nurse practitioners in ambulatory settings.

Science.gov (United States)

Xue, Ying; Tuttle, Jane

Nurse practitioners are increasingly being integrated into primary care delivery to help meet the growing demand for primary care. It is therefore important to understand nurse practitioners' productivity in primary care practice. We examined nurse practitioners' clinical productivity in regard to number of patients seen per week, whether they had a patient panel, and patient panel size. We further investigated practice characteristics associated with their clinical productivity. We conducted cross-sectional analysis of the 2012 National Sample Survey of Nurse Practitioners. The sample included full-time primary care nurse practitioners in ambulatory settings. Multivariable survey regression analyses were performed to examine the relationship between practice characteristics and nurse practitioners' clinical productivity. Primary care nurse practitioners in ambulatory settings saw an average of 80 patients per week (95% confidence interval [CI]: 79-82), and 64% of them had their own patient panel. The average patient panel size was 567 (95% CI: 522-612). Nurse practitioners who had their own patient panel spent a similar percent of time on patient care and documentation as those who did not. However, those with a patient panel were more likely to provide a range of clinical services to most patients. Nurse practitioners' clinical productivity was associated with several modifiable practice characteristics such as practice autonomy and billing and payment policies. The estimated number of patients seen in a typical week by nurse practitioners is comparable to that by primary care physicians reported in the literature. However, they had a significantly smaller patient panel. Nurse practitioners' clinical productivity can be further improved. Copyright © 2016 Elsevier Inc. All rights reserved.

Short-term to seasonal variability in factors driving primary productivity in a shallow estuary: Implications for modeling production

Science.gov (United States)

Canion, Andy; MacIntyre, Hugh L.; Phipps, Scott

2013-10-01

The inputs of primary productivity models may be highly variable on short timescales (hourly to daily) in turbid estuaries, but modeling of productivity in these environments is often implemented with data collected over longer timescales. Daily, seasonal, and spatial variability in primary productivity model parameters: chlorophyll a concentration (Chla), the downwelling light attenuation coefficient (kd), and photosynthesis-irradiance response parameters (Pmchl, αChl) were characterized in Weeks Bay, a nitrogen-impacted shallow estuary in the northern Gulf of Mexico. Variability in primary productivity model parameters in response to environmental forcing, nutrients, and microalgal taxonomic marker pigments were analysed in monthly and short-term datasets. Microalgal biomass (as Chla) was strongly related to total phosphorus concentration on seasonal scales. Hourly data support wind-driven resuspension as a major source of short-term variability in Chla and light attenuation (kd). The empirical relationship between areal primary productivity and a combined variable of biomass and light attenuation showed that variability in the photosynthesis-irradiance response contributed little to the overall variability in primary productivity, and Chla alone could account for 53-86% of the variability in primary productivity. Efforts to model productivity in similar shallow systems with highly variable microalgal biomass may benefit the most by investing resources in improving spatial and temporal resolution of chlorophyll a measurements before increasing the complexity of models used in productivity modeling.

Perceived effects of climate change on food crops production in Oyo ...

African Journals Online (AJOL)

The study assessed the perceived effects of climate change on food crops production in Oyo State. Multi stage sampling procedure was used in selecting 120 respondents for the study. Primary data was collected through interview schedule and it was analyzed using both descriptive and inferential statistics. Results reveal ...

A review of ocean chlorophyll algorithms and primary production models

Science.gov (United States)

Li, Jingwen; Zhou, Song; Lv, Nan

2015-12-01

This paper mainly introduces the five ocean chlorophyll concentration inversion algorithm and 3 main models for computing ocean primary production based on ocean chlorophyll concentration. Through the comparison of five ocean chlorophyll inversion algorithm, sums up the advantages and disadvantages of these algorithm,and briefly analyzes the trend of ocean primary production model.

Drivers of trophic amplification of ocean productivity trends in a changing climate

Science.gov (United States)

Stock, C. A.; Dunne, J. P.; John, J. G.

2014-07-01

Pronounced projected 21st century trends in regional oceanic net primary production (NPP) raise the prospect of significant redistributions of marine resources. Recent results further suggest that NPP changes may be amplified at higher trophic levels. Here, we elucidate the role of planktonic food web dynamics in driving projected changes in mesozooplankton production (MESOZP) found to be, on average, twice as large as projected changes in NPP by the latter half of the 21st century under a high emissions scenario. Globally, MESOZP was projected to decline by 7.9% but regional MESOZP changes sometimes exceeded 50%. Changes in three planktonic food web properties - zooplankton growth efficiency (ZGE), the trophic level of mesozooplankton (MESOTL), and the fraction of NPP consumed by zooplankton (zooplankton-phytoplankton coupling, ZPC), were demonstrated to be responsible for the projected amplification. Zooplankton growth efficiencies (ZGE) changed with NPP, amplifying both NPP increases and decreases. Negative amplification (i.e., exacerbation) of projected subtropical NPP declines via this mechanism was particularly strong since consumers in the subtropics already have limited surplus energy above basal metabolic costs. Increased mesozooplankton trophic level (MESOTL) resulted from projected declines in large phytoplankton production, the primary target of herbivorous mesozooplankton. This further amplified negative subtropical NPP declines but was secondary to ZGE and, at higher latitudes, was often offset by increased ZPC. Marked ZPC increases were projected for high latitude regions experiencing shoaling of deep winter mixing or decreased winter sea ice - both tending to increase winter zooplankton biomass and enhance grazer control of spring blooms. Increased ZPC amplified projected NPP increases associated with declining sea ice in the Artic and damped projected NPP declines associated with decreased mixing in the Northwest Atlantic and Southern Ocean

Recent Warming, Rather than Industrial Emissions of Bioavailable Nutrients, Is the Dominant Driver of Lake Primary Production Shifts across the Athabasca Oil Sands Region.

Directory of Open Access Journals (Sweden)

Jamie C Summers

Full Text Available Freshwaters in the Athabasca Oil Sands Region (AOSR are vulnerable to the atmospheric emissions and land disturbances caused by the local oil sands industry; however, they are also affected by climate change. Recent observations of increases in aquatic primary production near the main development area have prompted questions about the principal drivers of these limnological changes. Is the enhanced primary production due to deposition of nutrients (nitrogen and phosphorus from local industry or from recent climatic changes? Here, we use downcore, spectrally-inferred chlorophyll-a (VRS-chla profiles (including diagenetic products from 23 limnologically-diverse lakes with undisturbed catchments to characterize the pattern of primary production increases in the AOSR. Our aim is to better understand the relative roles of the local oil sands industry versus climate change in driving aquatic primary production trends. Nutrient deposition maps, generated using geostatistical interpolations of spring-time snowpack measurements from a grid pattern across the AOSR, demonstrate patterns of elevated total phosphorus, total nitrogen, and bioavailable nitrogen deposition around the main area of industrial activity. However, this pattern is not observed for bioavailable phosphorus. Our paleolimnological findings demonstrate consistently greater VRS-chla concentrations compared to pre-oil sands development levels, regardless of morphological and limnological characteristics, landscape position, bioavailable nutrient deposition, and dibenzothiophene (DBT-inferred industrial impacts. Furthermore, breakpoint analyses on VRS-chla concentrations across a gradient of DBT-inferred industrial impact show limited evidence of a contemporaneous change among lakes. Despite the contribution of bioavailable nitrogen to the landscape from industrial activities, we find no consistency in the spatial pattern and timing of VRS-chla shifts with an industrial fertilizing signal

Large historical growth in global terrestrial gross primary production

Energy Technology Data Exchange (ETDEWEB)

Campbell, J. E.; Berry, J. A.; Seibt, U.; Smith, S. J.; Montzka, S. A.; Launois, T.; Belviso, S.; Bopp, L.; Laine, M.

2017-04-05

Growth in terrestrial gross primary production (GPP) may provide a feedback for climate change, but there is still strong disagreement on the extent to which biogeochemical processes may suppress this GPP growth at the ecosystem to continental scales. The consequent uncertainty in modeling of future carbon storage by the terrestrial biosphere constitutes one of the largest unknowns in global climate projections for the next century. Here we provide a global, measurement-based estimate of historical GPP growth using long-term atmospheric carbonyl sulfide (COS) records derived from ice core, firn, and ambient air samples. We interpret these records using a model that relates changes in the COS concentration to changes in its sources and sinks, the largest of which is proportional to GPP. The COS history was most consistent with simulations that assume a large historical GPP growth. Carbon-climate models that assume little to no GPP growth predicted trajectories of COS concentration over the anthropogenic era that differ from those observed. Continued COS monitoring may be useful for detecting ongoing changes in GPP while extending the ice core record to glacial cycles could provide further opportunities to evaluate earth system models.

Yields of primary products from chloroethylenes in air under electron beam irradiation

International Nuclear Information System (INIS)

Hakoda, Teruyuki; Hashimoto, Shoji; Kojima, Takuji

2003-01-01

The quantitative analysis of toxic primary irradiation products was carried out for the development of the purification technology of chloroethylenes/air mixtures using an electron beam (EB). Degradation of chloroethylenes in humid air proceeded through the formation of primary products retaining a carbon-carbon (C-C) bond such as chloroacetyl chlorides and chloroacetyl aldehyde as well as that of primary products of COCl 2 and HCOCl through C-C bond cleavage. Chloroethylenes having one carbon bonded to two Cl atoms was decomposed into the primary products retaining a C-C bond prior to breaking a C-C bond. The number of Cl atoms of a chloroethylene molecule enhanced the formation ratio of primary products retaining a C-C bond. On the other hand, chloroethylene having two carbons bonded to one Cl atom was degraded thought the scission of a C-C bond predominantly C-C bond maintenance. (author)

Interannual Variation in Phytoplankton Class-specific Primary Production at a Global Scale

Science.gov (United States)

Rousseaux, Cecile; Gregg, Watson

2014-01-01

Phytoplankton is responsible for over half of the net primary production on earth. The knowledge on the contribution of various phytoplankton groups to the total primary production is still poorly understood. Data from satellite observations suggest that for upwelling regions, photosynthetic rates by microplankton is higher than that of nanoplankton but that when the spatial extent is considered, the production by nanoplankton is comparable or even larger than microplankton. Here, we used the NASA Ocean Biogeochemical Model (NOBM) combined with remote sensing data via assimilation to evaluate the contribution of 4 phytoplankton groups to the total primary production. Globally, diatoms were the group that contributed the most to the total phytoplankton production (approx. 50%) followed by coccolithophores and chlorophytes. Primary production by diatoms was highest in high latitude (>45 deg) and in major upwelling systems (Equatorial Pacific and Benguela system). We assessed the effects of climate variability on the class-specific primary production using global (i.e. Multivariate El Nino Index, MEI) and 'regional' climate indices (e.g. Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO)). Most interannual variability occurred in the Equatorial Pacific and was associated with climate variability. These results provide a modeling and data assimilation perspective to phytoplankton partitioning of primary production and contribute to our understanding of the dynamics of the carbon cycle in the oceans at a global scale.

Design considerations of fission and corrosion product in primary system of MONJU

International Nuclear Information System (INIS)

Yanagisawa, T.; Akagane, K.; Yamamoto, K.; Kawashima, K.

1976-01-01

General influence of fission and corrosion products in primary system on MONJU plant design is reviewed. Various research and development works are now in progress to decrease the generation rate, to remove the products more effectively and to develop the methods of evaluation the behaviour of radioactive products. The inventory and distribution of fission and corrosion products in the primary circuit of MONJU are given. The radiation levels on the primary components are estimated to be several roentgens per hour. (author)

Multi-directional productivity change

DEFF Research Database (Denmark)

Asmild, Mette; Balezentis, Tomas; Hougaard, Jens Leth

2016-01-01

In this paper we introduce an extension of the Malmquist total factor productivity index, which utilizes the Multi-directional Efficiency Analysis approach. This enables variable-specific analysis of productivity change as well as its components (efficiency change and technical change). The new...

Relative importance of phosphorus, invasive mussels and climate for patterns in chlorophyll a and primary production in Lakes Michigan and Huron

Science.gov (United States)

Warner, David M.; Lesht, Barry M.

2015-01-01

1. Lakes Michigan and Huron, which are undergoing oligotrophication after reduction of phosphorus loading, invasion by dreissenid mussels and variation in climate, provide an opportunity to conduct large-scale evaluation of the relative importance of these changes for lake productivity. We used remote sensing, field data and an information-theoretic approach to identify factors that showed statistical relationships with observed changes in chlorophyll a (chla) and primary production (PP). 2. Spring phosphorus (TP), annual mean chla and PP have all declined significantly in both lakes since the late 1990s. Additionally, monthly mean values of chla have decreased in many but not all months, indicating altered seasonal patterns. The most striking change has been the decrease in chla concentration during the spring bloom. 3. Mean chlorophyll a concentration was 17% higher in Lake Michigan than in Lake Huron, and total production for 2008 in Lake Michigan (9.5 tg year 1 ) was 10% greater than in Lake Huron (7.8 tg year 1 ), even though Lake Michigan is slightly smaller (by 3%) than Lake Huron. Differences between the lakes in the early 1970s evidently persisted to 2008. 4. Invasive mussels influenced temporal trends in spring chla and annual primary production. However, TP had a greater effect on chla and primary production than did the mussels, and TP varied independently from them. Two climatic variables (precipitation and air temperature in the basins) influenced annual chla and annual PP, while the extent of ice cover influenced TP but not chla or primary production. Our results demonstrate that observed temporal patterns in chla and PP are the result of complex interactions of P, climate and invasive mussels.

Impacts of temperature on primary productivity and respiration in naturally structured macroalgal assemblages.

Directory of Open Access Journals (Sweden)

Leigh W Tait

Full Text Available Rising global temperatures caused by human-mediated change has already triggered significant responses in organismal physiology, distribution and ecosystem functioning. Although the effects of rising temperature on the physiology of individual organisms are well understood, the effect on community-wide processes has remained elusive. The fixation of carbon via primary productivity is an essential ecosystem function and any shifts in the balance of primary productivity and respiration could alter the carbon balance of ecosystems. Here we show through a series of tests that respiration of naturally structured algal assemblages in southern New Zealand greatly increases with rising temperature, with implications for net primary productivity (NPP. The NPP of in situ macroalgal assemblages was minimally affected by natural temperature variation, possibly through photo-acclimation or temperature acclimation responses, but respiration rates and compensating irradiance were negatively affected. However, laboratory experiments testing the impacts of rising temperature on several photosynthetic parameters showed a decline in NPP, increasing respiration rates and increasing compensating irradiance. The respiration Q10 of laboratory assemblages (the difference in metabolic rates over 10°C averaged 2.9 compared to a Q10 of 2 often seen in other autotrophs. However, gross primary productivity (GPP Q10 averaged 2, indicating that respiration was more severely affected by rising temperature. Furthermore, combined high irradiance and high temperature caused photoinhibition in the laboratory, and resulted in 50% lower NPP at high irradiance. Our study shows that communities may be more severely affected by rising global temperatures than would be expected by responses of individual species. In particular, enhanced respiration rates and rising compensation points have the potential to greatly affect the carbon balance of macroalgal assemblages through declines in

Modeling the Sensitivity of Primary Production in Lake Michigan to Nutrient Loads with and without Dreissenid Mussels

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Dreissenid (quagga) mussels became established in large numbers in Lake Michigan beginning around 2004. Since then, significant changes have been observed in Lake Michigan open-water chlorophyll and nutrient concentrations, and in primary production. We updated the LM3-Eutro mode...

GHG emissions from primary aluminum production in China: Regional disparity and policy implications

International Nuclear Information System (INIS)

Hao, Han; Geng, Yong; Hang, Wen

2016-01-01

Highlights: • GHG emissions from primary aluminum production in China were accounted. • The impact of regional disparity of power generation was considered for this study. • GHG emissions factor of China’s primary aluminum production was 16.5 t CO_2e/t Al ingot in 2013. • Total GHG emissions from China’s primary aluminum production were 421 mt CO_2e in 2013. - Abstract: China is the world-leading primary aluminum production country, which contributed to over half of global production in 2014. Primary aluminum production is power-intensive, for which power generation has substantial impact on overall Greenhouse Gas (GHG) emissions. In this study, we explore the impact of regional disparity of China’s power generation system on GHG emissions for the sector of primary aluminum production. Our analysis reveals that the national GHG emissions factor (GEF) of China’s primary aluminum production was 16.5 t CO_2e/t Al ingot in 2013, with province-level GEFs ranging from 8.2 to 21.7 t CO_2e/t Al ingot. There is a high coincidence of provinces with high aluminum productions and high GEFs. Total GHG emissions from China’s primary aluminum production were 421 mt CO_2e in 2013, approximately accounting for 4% of China’s total GHG emissions. Under the 2020 scenario, GEF shows a 13.2% reduction compared to the 2013 level, but total GHG emissions will increase to 551 mt CO_2e. Based on our analysis, we recommend that the government should further promote energy efficiency improvement, facilitate aluminum industry redistribution with low-carbon consideration, promote secondary aluminum production, and improve aluminum industry data reporting and disclosure.

Primary productivity of the Andaman Sea

Digital Repository Service at National Institute of Oceanography (India)

Bhattathiri, P.M.A.; Devassy, V.P.

The average surface and column primary productivity, chl a and particulate organic carbon, estimated at 24 stations during Feb. 1979, were respectively 5.3 mg C/m3/d and 273 mg C/m2 /d; 0.03 mg/m3 and 3.64 mg/m2; and 132mg/m3 and 4.59 g/m2...

Twenty-million-year relationship between mammalian diversity and primary productivity

Science.gov (United States)

Fritz, Susanne A.; Eronen, Jussi T.; Schnitzler, Jan; Hof, Christian; Janis, Christine M.; Mulch, Andreas; Böhning-Gaese, Katrin; Graham, Catherine H.

2016-01-01

At global and regional scales, primary productivity strongly correlates with richness patterns of extant animals across space, suggesting that resource availability and climatic conditions drive patterns of diversity. However, the existence and consistency of such diversity–productivity relationships through geological history is unclear. Here we provide a comprehensive quantitative test of the diversity–productivity relationship for terrestrial large mammals through time across broad temporal and spatial scales. We combine >14,000 occurrences for 690 fossil genera through the Neogene (23–1.8 Mya) with regional estimates of primary productivity from fossil plant communities in North America and Europe. We show a significant positive diversity–productivity relationship through the 20-million-year record, providing evidence on unprecedented spatial and temporal scales that this relationship is a general pattern in the ecology and paleo-ecology of our planet. Further, we discover that genus richness today does not match the fossil relationship, suggesting that a combination of human impacts and Pleistocene climate variability has modified the 20-million-year ecological relationship by strongly reducing primary productivity and driving many mammalian species into decline or to extinction. PMID:27621451

Deposition and incorporation of corrosion product to primary coolant suppressing method

International Nuclear Information System (INIS)

Tsuzuki, Yasuo; Hasegawa, Naoyoshi; Fujioka, Tsunaaki.

1992-01-01

In a PWR type nuclear power plant, the concentration of dissolved nitrogen in primary coolants is increased by controlling the nitrogen partial pressure in a volume controlling tank gas phase portion or addition of water in a primary system water supply tank containing dissolved nitrogen to a primary system. Then ammonium is formed by a reaction with hydrogen dissolved in the primary coolants in the field of radiation rays, to control the concentration of ammonium in the coolants within a range from 0.5 to 3.5 ppm, and operate the power plant. As a result, deposition and incorporation of corrosion products to the structural materials of the primary system equipments during plant operation (pH 6.8 to 8.0) are suppressed. In other words, deposition of particulate corrosion products on the surface of fuel cladding tubes and the inner surface of pipelines in the primary system main equipments is prevented and incorporation of ionic radioactive corrosion products to the oxide membranes on the inner surface of the pipelines of the primary system main equipments is suppressed, to greatly reduce the radiation dose rate of the primary system pipelines. Thus, operator's radiation exposure can be decreased upon shut down of the plant. (N.H.)

Nutrient dynamics and primary production in a pristine coastal mangrove ecosystem: Andaman Islands, India

Science.gov (United States)

Jenkins, E. N.; Nickodem, K.; Siemann, A. L.; Hoeher, A.; Sundareshwar, P. V.; Ramesh, R.; Purvaja, R.; Banerjee, K.; Manickam, S.; Haran, H.

2012-12-01

Mangrove ecosystems play a key role in supporting coastal food webs and nutrient cycles in the coastal zone. Their strategic position between the land and the sea make them important sites for land-ocean interaction. As part of an Indo-US summer field course we investigated changes in the water chemistry in a pristine mangrove creek located at Wright Myo in the Andaman Islands, India. This study was conducted during the wet season (June 2012) to evaluate the influence of the coastal mangrove wetlands on the water quality and productivity in adjoining pelagic waters. Over a full tidal cycle spanning approximately 24 hrs, we measured nutrient concentrations and other ancillary parameters (e.g. dissolved oxygen, turbidity, salinity, etc.) hourly to evaluate water quality changes in incoming and ebbing tides. Nutrient analyses had the following concentration ranges (μM): nitrite 0.2-0.9, nitrate 2.0-11.5, ammonium 1.3-7.5, dissolved inorganic phosphate 0.7-2.8. The dissolved inorganic nitrogen to dissolved inorganic phosphate (DIN/DIP) ratio was very low relative to an optimal ratio, suggesting growth is nitrogen limited. In addition, we conducted primary production assays to investigate the factors that controlled primary production in this pristine creek. The experiment was carried out in situ using the Winkler method at low and high tide. Four-hour incubation of light and dark bottles representing a fixed control, non-fertilized, fertilized with nitrate, and fertilized with phosphate enabled the measurement of both net oxygen production and dark respiration. The low tide experiment suggests the ecosystem is heterotrophic because the oxygen measured in the light bottles was consistently less than that of the dark bottles. This result may be an experimental artifact of placing the glass bottles in the sun for too long prior to incubation, potentially leading to photolysis of large organic molecules in the light bottles. The high tide experiment also displayed

Relative importance of climate changes at different time scales on net primary productivity-a case study of the Karst area of northwest Guangxi, China.

Science.gov (United States)

Liu, Huiyu; Zhang, Mingyang; Lin, Zhenshan

2017-10-05

Climate changes are considered to significantly impact net primary productivity (NPP). However, there are few studies on how climate changes at multiple time scales impact NPP. With MODIS NPP product and station-based observations of sunshine duration, annual average temperature and annual precipitation, impacts of climate changes at different time scales on annual NPP, have been studied with EEMD (ensemble empirical mode decomposition) method in the Karst area of northwest Guangxi, China, during 2000-2013. Moreover, with partial least squares regression (PLSR) model, the relative importance of climatic variables for annual NPP has been explored. The results show that (1) only at quasi 3-year time scale do sunshine duration and temperature have significantly positive relations with NPP. (2) Annual precipitation has no significant relation to NPP by direct comparison, but significantly positive relation at 5-year time scale, which is because 5-year time scale is not the dominant scale of precipitation; (3) the changes of NPP may be dominated by inter-annual variabilities. (4) Multiple time scales analysis will greatly improve the performance of PLSR model for estimating NPP. The variable importance in projection (VIP) scores of sunshine duration and temperature at quasi 3-year time scale, and precipitation at quasi 5-year time scale are greater than 0.8, indicating important for NPP during 2000-2013. However, sunshine duration and temperature at quasi 3-year time scale are much more important. Our results underscore the importance of multiple time scales analysis for revealing the relations of NPP to changing climate.

Climate Change Impacts on Crop Production in Nigeria

Science.gov (United States)

Mereu, V.; Gallo, A.; Carboni, G.; Spano, D.

2011-12-01

The agricultural sector in Nigeria is particularly important for the country's food security, natural resources, and growth agenda. The cultivable areas comprise more than 70% of the total area; however, the cultivated area is about the 35% of the total area. The most important components in the food basket of the nation are cereals and tubers, which include rice, maize, corn, millet, sorghum, yam, and cassava. These crops represent about 80% of the total agricultural product in Nigeria (from NPAFS). The major crops grown in the country can be divided into food crops (produced for consumption) and export products. Despite the importance of the export crops, the primary policy of agriculture is to make Nigeria self-sufficient in its food and fiber requirements. The projected impacts of future climate change on agriculture and water resources are expected to be adverse and extensive in these area. This implies the need for actions and measures to adapt to climate change impacts, and especially as they affect agriculture, the primary sector for Nigerian economy. In the framework of the Project Climate Risk Analysis in Nigeria (founded by World Bank Contract n.7157826), a study was made to assess the potential impact of climate change on the main crops that characterize Nigerian agriculture. The DSSAT-CSM (Decision Support System for Agrotechnology Transfer - Cropping System Model) software, version 4.5 was used for the analysis. Crop simulation models included in DSSAT are tools that simulate physiological processes of crop growth, development and production by combining genetic crop characteristics and environmental (soil and weather) conditions. For each selected crop, the models were calibrated to evaluate climate change impacts on crop production. The climate data used for the analysis are derived by the Regional Circulation Model COSMO-CLM, from 1971 to 2065, at 8 km of spatial resolution. The RCM model output was "perturbed" with 10 Global Climate Models to have

Influence of the Phytoplankton Community Structure on the Spring and Annual Primary Production in the Northwestern Mediterranean Sea

Science.gov (United States)

Mayot, Nicolas; D'Ortenzio, Fabrizio; Uitz, Julia; Gentili, Bernard; Ras, Joséphine; Vellucci, Vincenzo; Golbol, Melek; Antoine, David; Claustre, Hervé

2017-12-01

Satellite ocean color observations revealed that unusually deep convection events in 2005, 2006, 2010, and 2013 led to an increased phytoplankton biomass during the spring bloom over a large area of the northwestern Mediterranean Sea (NWM). Here we investigate the effects of these events on the seasonal phytoplankton community structure, we quantify their influence on primary production, and we discuss the potential biogeochemical impact. For this purpose, we compiled in situ phytoplankton pigment data from five ship surveys performed in the NWM and from monthly cruises at a fixed station in the Ligurian Sea. We derived primary production rates from a light photosynthesis model applied to these in situ data. Our results confirm that the maximum phytoplankton biomass during the spring bloom is larger in years associated with intense deep convection events (+51%). During these enhanced spring blooms, the contribution of diatoms to total phytoplankton biomass increased (+33%), as well as the primary production rate (+115%). The occurrence of a highly productive bloom is also related to an increase in the phytoplankton bloom area (+155%) and in the relative contribution of diatoms to primary production (+63%). Therefore, assuming that deep convection in the NWM could be significantly weakened by future climate changes, substantial decreases in the spring production of organic carbon and of its export to deep waters can be expected.

Climate engineering and the ocean: effects on biogeochemistry and primary production

Science.gov (United States)

Lauvset, Siv K.; Tjiputra, Jerry; Muri, Helene

2017-12-01

Here we use an Earth system model with interactive biogeochemistry to project future ocean biogeochemistry impacts from the large-scale deployment of three different radiation management (RM) climate engineering (also known as geoengineering) methods: stratospheric aerosol injection (SAI), marine sky brightening (MSB), and cirrus cloud thinning (CCT). We apply RM such that the change in radiative forcing in the RCP8.5 emission scenario is reduced to the change in radiative forcing in the RCP4.5 scenario. The resulting global mean sea surface temperatures in the RM experiments are comparable to those in RCP4.5, but there are regional differences. The forcing from MSB, for example, is applied over the oceans, so the cooling of the ocean is in some regions stronger for this method of RM than for the others. Changes in ocean net primary production (NPP) are much more variable, but SAI and MSB give a global decrease comparable to RCP4.5 (˜ 6 % in 2100 relative to 1971-2000), while CCT gives a much smaller global decrease of ˜ 3 %. Depending on the RM methods, the spatially inhomogeneous changes in ocean NPP are related to the simulated spatial change in the NPP drivers (incoming radiation, temperature, availability of nutrients, and phytoplankton biomass) but mostly dominated by the circulation changes. In general, the SAI- and MSB-induced changes are largest in the low latitudes, while the CCT-induced changes tend to be the weakest of the three. The results of this work underscore the complexity of climate impacts on NPP and highlight the fact that changes are driven by an integrated effect of multiple environmental drivers, which all change in different ways. These results stress the uncertain changes to ocean productivity in the future and advocate caution at any deliberate attempt at large-scale perturbation of the Earth system.

Benthic primary production and mineralization in a High Arctic Fjord

DEFF Research Database (Denmark)

Attard, Karl M.; Hancke, Kasper; Sejr, Mikael K.

2016-01-01

Coastal and shelf systems likely exert major influence on Arctic Ocean functioning, yet key ecosystem processes remain poorly quantified. We employed the aquatic eddy covariance (AEC) oxygen (O2) flux method to estimate benthic primary production and mineralization in a High Arctic Greenland fjord....... Seabed gross primary production (GPP) within the 40 m deep photic zone was highest at 10 m (29 mmol O2 m−2 d−1) and decreased to 5 mmol O2 m−2 d−1 at 40 m, while nighttime community respiration (CR) ranged from 11 to 25 mmol O2m−2 d−1. CR decreased to ~2.5 mmol O2m−2 d−1 at 80 m and remained constant...... with further depth. Fauna activity accounted for ~50% of the CR at depths ≤60 m but was primary production...

On Tour... Primary Hardwood Processing, Products and Recycling Unit

Science.gov (United States)

Philip A. Araman; Daniel L. Schmoldt

1995-01-01

Housed within the Department of Wood Science and Forest Products at Virginia Polytechnic Institute is a three-person USDA Forest Service research work unit (with one vacancy) devoted to hardwood processing and recycling research. Phil Araman is the project leader of this truly unique and productive unit, titled ãPrimary Hardwood Processing, Products and Recycling.ä The...

Consequences of buffelgrass pasture development for primary productivity, perennial plant richness, and vegetation structure in the drylands of Sonora, Mexico.

Science.gov (United States)

Franklin, Kimberly; Molina-Freaner, Francisco

2010-12-01

In large parts of northern Mexico native plant communities are being converted to non-native buffelgrass (Pennisetum ciliare) pastures, and this conversion could fundamentally alter primary productivity and species richness. In Sonora, Mexico land conversion is occurring at a regional scale along a rainfall-driven gradient of primary productivity, across which native plant communities transition from desert scrub to thorn scrub. We used a paired sampling design to compare a satellite-derived index of primary productivity, richness of perennial plant species, and canopy-height profiles of native plant communities with buffelgrass pastures. We sampled species richness across a gradient of primary productivity in desert scrub and thorn scrub vegetation to examine the influence of site productivity on the outcomes of land conversion. We also examined the influence of pasture age on species richness of perennial plants. Index values of primary productivity were lower in buffelgrass pastures than in native vegetation, which suggests a reduction in primary productivity. Land conversion reduced species richness by approximately 50% at local and regional scales, reduced tree and shrub cover by 78%, and reduced canopy height. Land conversion disproportionately reduced shrub species richness, which reflects the common practice among Sonoran ranchers of conserving certain tree and cactus species. Site productivity did not affect the outcomes of land conversion. The age of a buffelgrass pasture was unrelated to species richness within the pasture, which suggests that passive recovery of species richness to preconversion levels is unlikely. Our findings demonstrate that land conversion can result in large losses of plant species richness at local and regional scales and in substantial changes to primary productivity and vegetation structure, which casts doubt on the feasibility of restoring native plant communities without active intervention on the part of land managers. �

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

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...

Chlorophyll fluorescence better captures seasonal and interannual gross primary productivity dynamics across dryland ecosystems of southwestern North America

Science.gov (United States)

Satellite remote sensing provides unmatched spatiotemporal information on vegetation gross primary productivity (GPP). Yet, understanding of the relationship between GPP and remote sensing observations and how it changes as a function of factors such as scale, biophysical constraint, and vegetation ...

Mass extinctions: Ecological selectivity and primary production

Science.gov (United States)

Rhodes, Melissa Clark; Thayer, Charles W.

1991-09-01

If mass extinctions were caused by reduced primary productivity, then extinctions should be concentrated among animals with starvation-susceptible feeding modes, active lifestyles, and high-energy budgets. The stratigraphic ranges (by stage) of 424 genera of bivalves and 309 genera of articulate brachiopods suggest that there was an unusual reduction of primary productivity at the Cretaceous/Tertiary (K/T) boundary extinction. For bivalves at the K/T, there were (1) selective extinction of suspension feeders and other susceptible trophic categories relative to deposit feeders and other resistant categories, and (2) among suspension feed-ers, selective extinction of bivalves with active locomotion. During the Permian-Triassic (P/Tr) extinction and Jurassic background time, extinction rates among suspension feeders were greater for articulate brachiopods than for bivalves. But during the K/T event, extinction rates of articulates and suspension-feeding bivalves equalized, possibly because the low-energy budgets of articulates gave them an advantage when food was scarce.

Pharma Success in Product Development—Does Biotechnology Change the Paradigm in Product Development and Attrition.

Science.gov (United States)

Evens, Ronald P

2016-01-01

The biotechnology segment of the overall biopharma industry has existed for only about 40–45 years, as a driver of new product development. This driving force was initiated with the FDA approval of recombinant human insulin in 1982, originating from the Genentech company. The pharma industry in the early years of 1970s and 1980s engaged with biotechnology companies only to a small extent with their in-licensing of a few recombinant molecules, led by Roche, Eli Lilly, and Johnson and Johnson. However, subsequently and dramatically over the last 25 years, biotechnology has become a primary driver of product and technology innovation and has become a cornerstone in new product development by all biopharma companies. This review demonstrates these evolutionary changes regarding approved products, product pipelines, novelty of the products, FDA approval rates, product sales, financial R&D investments in biotechnology, partnerships, mergers and acquisitions, and patent issues. We now have about 300 biotechnology products approved in USA covering 16 medical disciplines and about 250 indications, with the engagement of 25 pharma companies, along with their biotechnology company innovators and partners. The biotechnology pipeline involves over 1000 molecules in clinical trials, including over 300 molecules associated with the top 10 pharma companies. Product approval rates by the FDA for biotechnology products are over double the rate for drugs. Yes, the R&D paradigm has changed with biotechnology now as one of the major focuses for new product development with novel molecules by the whole biopharma industry.

Spatial and temporal variability of chlorophyll and primary productivity in surface waters of southern Chile (41.5 43° S)

Science.gov (United States)

Iriarte, J. L.; González, H. E.; Liu, K. K.; Rivas, C.; Valenzuela, C.

2007-09-01

The southern fjord region of Chile is a unique ecosystem characterized by complex marine-terrestrial-atmospheric interactions that result in high biological production. Since organic nitrogen from terrestrial and atmospheric compartments is highly significant in this region (>40%), as is the low NO 3:PO 4 ratio in surface waters, it is suggested that fertilization from inorganic and organic nitrogen sources has a strong influence on both phytoplankton biomass/primary production and harmful algae bloom dynamics. The data presented in this paper provide an opportunity to improve our knowledge of phytoplankton dynamics on temporal and spatial mesoscales. Ocean color data from NASA (SeaWiFS) for chlorophyll and primary production estimates and in situ surface measurement of inorganic nutrients, phytoplankton biomass, and primary productivity revealed that the coastal waters of southern Chile have a classical spring and autumn chlorophyll bloom cycle in which primary production is co-limited by strong seasonal changes in light and nitrate. During spring blooms, autotrophic biomass (such as chlorophyll a, Chl- a) and primary production estimates reached 25 mg Chl- a m -3 and 23 mg C m -3 h -1, respectively, and micro-phytoplankton accounted for a significant portion of the biomass (60%) in spring. The contribution of phytoplankton size classes to total chlorophyll a revealed the dominance of nanoplankton (>50%) in winter and post-bloom periods (<1.0 mg Chl- a m -3).

Corrosion products in the primary circuits of PWRs

International Nuclear Information System (INIS)

Darras, R.

1983-01-01

The characteristics of PWR primary circuits are recalled, particularly the chemical specifications of the medium and the various materials used (austenitic steel, nickel alloys, cobalt-based alloys and zirconium alloys). The behaviour of these materials as regards general corrosion in nominal and transient conditions is then outlined briefly, special emphasis being laid on the effect of the determining parameters on the quantity of corrosion products formed. The release of the latter into the primary coolant is caused by two main processes: solubilization and erosion. Particular attention was given therefore to the laws governing the solubility of the oxides involved, especially as a function of temperature and pH. Erosion, or release in the form of solid particles, is relatively severe during transient events. As these corrosion products are then carried through all circuits, they cause deposits to form in favourable places on the walls as a result either of precipitation of soluble species or of sedimentation followed by consolidation of suspended particles. The presence of corrosion products in the primary circuits creates a particular impact since they become radioactive as they pass through the core and especially when they remain in it in the form of deposits; as a result, the products are capable of contaminating the entire system. Finally, although long-term reliability is obviously an essential condition for materials developed, attention must also be given to problems associated with a build-up of corrosion products in the cooling circuits and efforts made to minimize them. To that end, a number of precautions are recommended, and various remedies can be applied: selecting materials which are not readily activated, keeping structures clean, purifying fluids properly, restricting solubilization and precipitation, and perhaps, periodic decontamination. (author)

Production and Utilization of Core-Textbooks in Primary School ...

African Journals Online (AJOL)

Production and Utilization of Core-Textbooks in Primary School System: Impact of Authors and Publishers. ... These stakeholders have specific roles to play and cannot operate in isolation. The study, therefore investigated the influence of authorship and publishers on core textbook production and utilisation in Oyo State ...

Teaching Primary School Music: Coping with Changing Work Conditions

Science.gov (United States)

de Vries, Peter Andrew

2018-01-01

The changing roles of two primary (elementary) school music teachers are explored in this article, and how these changed roles have impacted on music programmes in their respective schools. Change readiness provides the theoretical framework for investigating the way both teachers responded to their changing roles. The first teacher's role changed…

Seasonality of primary and secondary production in an Arctic river

Science.gov (United States)

Kendrick, M.; Huryn, A.; Deegan, L.

2011-12-01

Rivers and streams that freeze solid for 8-9 months each year provide excellent examples of the extreme seasonality of arctic habitats. The communities of organisms inhabiting these rivers must complete growth and development during summer, resulting in a rapid ramp-up and down of production over the short ice-free period. The effects of recent shifts in the timing of the spring thaw and autumn freeze-up on the duration and pattern of the period of active production are poorly understood. We are currently investigating: 1) the response of the biotic community of the Kuparuk River (Arctic Alaska) to shifts in the seasonality of the ice-free period, and 2) the community response to increases in phosphorous (P) supply anticipated as the volume of the permafrost active-layer increases in response to climate warming. Here algal production supports a 2-tier web of consumers. We tracked primary and secondary production from the spring thaw through mid-August in a reference reach and one receiving low-level P fertilization. Gross primary production/community respiration (GPP/R) ratios for both reaches were increasing through mid-July, with higher GPP/R in response to the P addition. Understanding the degree of synchrony between primary and secondary production in this Arctic river system will enhance further understanding of how shifts in seasonality affect trophic dynamics.

Distortion product otoacoustic emissions: comparison of sequential vs. simultaneous presentation of primary tones.

Science.gov (United States)

Kumar, U Ajith; Maruthy, Sandeep; Chandrakant, Vishwakarma

2009-03-01

Distortion product otoacoustic emissions are one form of evoked otoacoustic emissions. DPOAEs provide the frequency specific information about the hearing status in mid and high frequency regions. But in most screening protocols TEOAEs are preferred as it requires less time compared to DPOAE. This is because, in DPOAE each stimulus is presented one after the other and responses are analyzed. Grason and Stadler Incorporation 60 (GSI-60) offer simultaneous presentation of four sets of primary tones at a time and checks for the DPOAE. In this mode of presentation, all the pairs are presented at a time and following that response is extracted separately whereas, in sequential mode primaries are presented in orderly fashion one after the other. In this article simultaneous and sequential protocols were used to compare the Distortion product otoacoustic emission amplitude, noise floor and administration time in individuals with normal hearing and mild sensori-neural (SN) hearing loss. In simultaneous protocols four sets of primary tones (i.e. 8 tones) were presented together whereas, in sequential presentation mode one set of primary tones was presented each time. Simultaneous protocol was completed in less than half the time required for the completion of sequential protocol. Two techniques yielded similar results at frequencies above 1000 Hz only in normal hearing group. In SN hearing loss group simultaneous presentation yielded signifi cantly higher noise floors and distortion product amplitudes. This result challenges the use of simultaneous presentation technique in neonatal hearing screening programmes and on other pathologies. This discrepancy between two protocols may be due to some changes in biomechanical process in the cochlear and/or due to higher distortion/noise produced by the system during the simultaneous presentation mode.

Primary Productivity, NASA Aqua MODIS, 4.4 km, Global, EXPERIMENTAL

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Primary Productivity is calculated from NASA Aqua MODIS Chl a SST data. THIS IS AN EXPERIMENTAL PRODUCT: intended strictly for scientific evaluation by professional...

Hot-spots of primary productivity: An Alternative interpretation to Conventional upwelling models

Science.gov (United States)

van Ruth, Paul D.; Ganf, George G.; Ward, Tim M.

2010-12-01

The eastern Great Australian Bight (EGAB) forms part of the Southern and Indian Oceans and is an area of high ecological and economic importance. Although it supports a commercial fishery, quantitative estimates of the primary productivity underlying this industry are open to debate. Estimates range from 500 mg C m -2 day -1. Part of this variation may be due to the unique upwelling circulation of shelf waters in summer/autumn (November-April), which shares some similarities with highly productive eastern boundary current upwelling systems, but differs due to the influence of a northern boundary current, the Flinders current, and a wide continental shelf. This study examines spatial variations in primary productivity in the EGAB during the upwelling seasons of 2005 and 2006. Daily integral productivity calculated using the vertically generalised production model (VGPM) showed a high degree of spatial variation. Productivity was low (modelled with the VGPM, which uses surface measures of phytoplankton biomass to calculate productivity. Macro-nutrient concentrations could not be used to explain the difference in the low and high productivities (silica > 1 μmol L -1, nitrate/nitrite > 0.4 μmol L -1, phosphate > 0.1 μmol L -1). Mixing patterns or micro-nutrient concentrations are possible explanations for spatial variations in primary productivity in the EGAB. On a global scale, daily rates of primary productivity of the EGAB lie between the highly productive eastern boundary current upwelling systems, and less productive coastal regions of western and south eastern Australia, and the oligotrophic ocean. However, daily productivity rates in the upwelling hotspots of the EGAB rival productivities in Benguela and Humboldt currents.

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...

Primary productivity in nearshore waters of Thal, Maharashtra coast

Digital Repository Service at National Institute of Oceanography (India)

Varshney, P.K.; Nair, V.R.; Abidi, S.A.H.

Primary productivity off Thal, Maharashtra, India was evaluated at 3 stations during Feb. 1980 to Jan. 1981. The area was quite turbid and the euphotic zone never exceeded 2.5 m. Column production ranged from 0.69 to 605.21 mg C.m/2.d/2 (av. 78.2 mg...

Spatial patterns of primary productivity derived from the Dynamic Habitat Indices predict patterns of species richness and distributions in the tropics

Science.gov (United States)

Suttidate, Naparat

Humans are changing the Earth's ecosystems, which has profound consequences for biodiversity. To understand how species respond to these changes, biodiversity science requires accurate assessments of biodiversity. However, biodiversity assessments are still limited in tropical regions. The Dynamic Habitat Indices (DHIs), derived from satellite data, summarize dynamic patterns of annual primary productivity: (a) cumulative annual productivity, (b) minimum annual productivity, and (c) seasonal variation in productivity. The DHIs have been successfully used in temperate regions, but not yet in the tropics. My goal was to evaluate the importance of primary productivity measured via the DHIs for assessing patterns of species richness and distributions in Thailand. First, I assessed the relationships between the DHIs and tropical bird species richness. I also evaluated the complementarity of the DHIs and topography, climate, latitudinal gradients, habitat heterogeneity, and habitat area in explaining bird species richness. I found that among three DHIs, cumulative annual productivity was the most important factor in explaining bird species richness and that the DHIs outperformed other environmental variables. Second, I developed texture measures derive from DHI cumulative annual productivity, and compared them to habitat composition and fragmentation as predictors of tropical forest bird distributions. I found that adding texture measures to habitat composition and fragmentation models improved the prediction of tropical bird distributions, especially area- and edge-sensitive tropical forest bird species. Third, I predicted the effects of trophic interactions between primary productivity, prey, and predators in relation to habitat connectivity for Indochinese tigers (Panthera tigris). I found that including trophic interactions improved habitat suitability models for tigers. However, tiger habitat is highly fragmented with few dispersal corridors. I also identified

Directional and Spectral Irradiance in Ocean Models: Effects on Simulated Global Phytoplankton, Nutrients, and Primary Production

Science.gov (United States)

Gregg, Watson W.; Rousseaux, Cecile S.

2016-01-01

The importance of including directional and spectral light in simulations of ocean radiative transfer was investigated using a coupled biogeochemical-circulation-radiative model of the global oceans. The effort focused on phytoplankton abundances, nutrient concentrations and vertically-integrated net primary production. The importance was approached by sequentially removing directional (i.e., direct vs. diffuse) and spectral irradiance and comparing results of the above variables to a fully directionally and spectrally-resolved model. In each case the total irradiance was kept constant; it was only the pathways and spectral nature that were changed. Assuming all irradiance was diffuse had negligible effect on global ocean primary production. Global nitrate and total chlorophyll concentrations declined by about 20% each. The largest changes occurred in the tropics and sub-tropics rather than the high latitudes, where most of the irradiance is already diffuse. Disregarding spectral irradiance had effects that depended upon the choice of attenuation wavelength. The wavelength closest to the spectrally-resolved model, 500 nm, produced lower nitrate (19%) and chlorophyll (8%) and higher primary production (2%) than the spectral model. Phytoplankton relative abundances were very sensitive to the choice of non-spectral wavelength transmittance. The combined effects of neglecting both directional and spectral irradiance exacerbated the differences, despite using attenuation at 500 nm. Global nitrate decreased 33% and chlorophyll decreased 24%. Changes in phytoplankton community structure were considerable, representing a change from chlorophytes to cyanobacteria and coccolithophores. This suggested a shift in community function, from light-limitation to nutrient limitation: lower demands for nutrients from cyanobacteria and coccolithophores favored them over the more nutrient-demanding chlorophytes. Although diatoms have the highest nutrient demands in the model, their

Phytoplankton primary production in the world's estuarine-coastal ecosystems

Science.gov (United States)

Cloern, James E.; Foster, S.Q.; Kleckner, A.E.

2014-01-01

reported values of APPP, 958 come from sites between 30 and 60° N; we found only 36 for sites south of 20° N. Second, of the 131 ecosystems where APPP has been reported, 37% are based on measurements at only one location during 1 year. The accuracy of these values is unknown but probably low, given the large interannual and spatial variability within ecosystems. Finally, global assessments are confounded by measurements that are not intercomparable because they were made with different methods. Phytoplankton primary production along the continental margins is tightly linked to variability of water quality, biogeochemical processes including ocean–atmosphere CO2 exchange, and production at higher trophic levels including species we harvest as food. The empirical record has deficiencies that preclude reliable global assessment of this key Earth system process. We face two grand challenges to resolve these deficiencies: (1) organize and fund an international effort to use a common method and measure APPP regularly across a network of coastal sites that are globally representative and sustained over time, and (2) integrate data into a unifying model to explain the wide range of variability across ecosystems and to project responses of APPP to regional manifestations of global change as it continues to unfold.

Performance analysis of spectrum sensing with multiple status changes in primary user traffic

KAUST Repository

Tang, Liang

2012-06-01

In this letter, the impact of primary user traffic with multiple status changes on the spectrum sensing performance is analyzed. Closed-form expressions for the probabilities of false alarm and detection are derived. Numerical results show that the multiple status changes of the primary user cause considerable degradation in the sensing performance. This degradation depends on the number of changes, the primary user traffic model, the primary user traffic intensity and the signal-to-noise ratio of the received signal. Numerical results also show that the amount of degradation decreases when the number of changes increases, and converges to a minimum sensing performance due to the limited sensing period and primary holding time. © 2012 IEEE.

Changing the lens: widening the approach to primary care research.

Science.gov (United States)

Checkland, Kath

2003-10-01

After years of being shielded from most of the managerial and organisational changes in health care, primary care is going through a period of change in many countries. Much of the research that has been done in primary care, in common with that in secondary care, puts at the centre of its methodology the concept of professionalism. However, there are other ways of theorising medical work, and using a wider range of theoretical 'lenses' when planning research into the impact of change will enhance and enrich that research. Viewing primary care physicians as 'workers', concerned, like other workers, with constructing understanding of what they do that helps them cope with pressures and uncertainties, shifts the focus of research questions away from issues of professional status towards the practical ways in which they deal with change in their local contexts. Research using this theoretical approach may be able to explain phenomena that other, more broad-brush approaches cannot.

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.

Food waste quantification in primary production - The Nordic countries as a case study.

Science.gov (United States)

Hartikainen, Hanna; Mogensen, Lisbeth; Svanes, Erik; Franke, Ulrika

2018-01-01

Our understanding of food waste in the food supply chain has increased, but very few studies have been published on food waste in primary production. The overall aims of this study were to quantify the total amount of food waste in primary production in Finland, Sweden, Norway and Denmark, and to create a framework for how to define and quantify food waste in primary production. The quantification of food waste was based on case studies conducted in the present study and estimates published in scientific literature. The chosen scope of the study was to quantify the amount of edible food (excluding inedible parts like peels and bones) produced for human consumption that did not end up as food. As a result, the quantification was different from the existing guidelines. One of the main differences is that food that ends up as animal feed is included in the present study, whereas this is not the case for the recently launched food waste definition of the FUSIONS project. To distinguish the 'food waste' definition of the present study from the existing definitions and to avoid confusion with established usage of the term, a new term 'side flow' (SF) was introduced as a synonym for food waste in primary production. A rough estimate of the total amount of food waste in primary production in Finland, Sweden, Norway and Denmark was made using SF and 'FUSIONS Food Waste' (FFW) definitions. The SFs in primary production in the four Nordic countries were an estimated 800,000 tonnes per year with an additional 100,000 tonnes per year from the rearing phase of animals. The 900,000 tonnes per year of SF corresponds to 3.7% of the total production of 24,000,000 tonnes per year of edible primary products. When using the FFW definition proposed by the FUSIONS project, the FFW amount was estimated at 330,000 tonnes per year, or 1% of the total production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Climate change and its impacts on vegetation distribution and net primary productivity of the alpine ecosystem in the Qinghai-Tibetan Plateau.

Science.gov (United States)

Gao, Qingzhu; Guo, Yaqi; Xu, Hongmei; Ganjurjav, Hasbagen; Li, Yue; Wan, Yunfan; Qin, Xiaobo; Ma, Xin; Liu, Shuo

2016-06-01

Changes in climate have caused impacts on ecosystems on all continents scale, and climate change is also projected to be a stressor on most ecosystems even at the rate of low- to medium-range warming scenarios. Alpine ecosystem in the Qinghai-Tibetan Plateau is vulnerable to climate change. To quantify the climate change impacts on alpine ecosystems, we simulated the vegetation distribution and net primary production in the Qinghai-Tibetan Plateau for three future periods (2020s, 2050s and 2080s) using climate projection for RCPs (Representative Concentration Pathways) RCP4.5 and RCP8.5 scenarios. The modified Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ model) was parameter and test to make it applicable to the Qinghai-Tibetan Plateau. Climate projections that were applied to LPJ model in the Qinghai-Tibetan Plateau showed trends toward warmer and wetter conditions. Results based on climate projections indicated changes from 1.3°C to 4.2°C in annual temperature and changes from 2% to 5% in annual precipitation. The main impacts on vegetation distribution was increase in the area of forests and shrubs, decrease in alpine meadows which mainly replaced by shrubs which dominated the eastern plateau, and expanding in alpine steppes to the northwest dominated the western and northern plateau. The NPP was projected to increase by 79% and 134% under the RCP4.5 and RCP8.5. The projected NPP generally increased about 200gC·m(-2)·yr(-1) in most parts of the plateau with a gradual increase from the eastern to the western region of the Qinghai-Tibetan Plateau at the end of this century. Copyright © 2016 Elsevier B.V. All rights reserved.

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

Primary production in a tropical large lake: The role of phytoplankton composition

International Nuclear Information System (INIS)

Darchambeau, F.; Sarmento, H.; Descy, J.-P.

2014-01-01

Phytoplankton biomass and primary production in tropical large lakes vary at different time scales, from seasons to centuries. We provide a dataset made of 7 consecutive years of phytoplankton biomass and production in Lake Kivu (Eastern Africa). From 2002 to 2008, bi-weekly samplings were performed in a pelagic site in order to quantify phytoplankton composition and biomass, using marker pigments determined by HPLC. Primary production rates were estimated by 96 in situ 14 C incubations. A principal component analysis showed that the main environmental gradient was linked to a seasonal variation of the phytoplankton assemblage, with a clear separation between diatoms during the dry season and cyanobacteria during the rainy season. A rather wide range of the maximum specific photosynthetic rate (P Bm ) was found, ranging between 1.15 and 7.21 g carbon g −1 chlorophyll a h −1 , and was best predicted by a regression model using phytoplankton composition as an explanatory variable. The irradiance at the onset of light saturation (I k ) ranged between 91 and 752 μE m −2 s −1 and was linearly correlated with the mean irradiance in the mixed layer. The inter-annual variability of phytoplankton biomass and production was high, ranging from 53 to 100 mg chlorophyll a m −2 (annual mean) and from 143 to 278 g carbon m −2 y −1 , respectively. The degree of seasonal mixing determined annual production, demonstrating the sensitivity of tropical lakes to climate variability. A review of primary production of other African great lakes allows situating Lake Kivu productivity in the same range as that of lakes Tanganyika and Malawi, even if mean phytoplankton biomass was higher in Lake Kivu. - Highlights: • We provide a 7-year dataset of primary production in a tropical great lake. • Specific photosynthetic rate was determined by community composition. • Annual primary production varied between 143 and 278 mg C m −2 y −1 . • Pelagic production was highly

Global Malmquist indices of productivity change in Egyptian wheat production

Energy Technology Data Exchange (ETDEWEB)

Elasraag, Y.H.; Alarcón, S.

2017-07-01

This study aims to measure the total factor productivity of the main govern orates of wheat production in Egypt during the time period 1990-2012 and decompose it into technical change, efficiency change and scale change. We used Global Malmquist TFP index as a non-parametric approach. The results indicated that the contribution of technical change component is more important than the efficiency change component. In fact technical change rose, 25.7%, while efficiency change presented a little decline, 3.7%. The decomposition of efficiency change indicated that the main problem of wheat production in Egypt was scale efficiency that worsened by 5.5%.

Seasonal variability of primary production in a fjord ecosystem of the Chilean Patagonia: Implications for the transfer of carbon within pelagic food webs

Science.gov (United States)

Montero, Paulina; Daneri, Giovanni; González, Humberto E.; Iriarte, Jose Luis; Tapia, Fabián J.; Lizárraga, Lorena; Sanchez, Nicolas; Pizarro, Oscar

2011-03-01

We characterized the seasonal cycle of productivity in Reloncaví Fjord (41°30'S), Chilean Patagonia. Seasonal surveys that included measurements of gross primary production, community respiration, bacterioplankton secondary production, and sedimentation rates along the fjord were combined with continuous records of water-column temperature variability and wind forcing, as well as satellite-derived data on regional patterns of wind stress, sea surface temperatures, and surface chlorophyll concentrations. The hydrography and perhaps fjord productivity respond to the timing and intensity of wind forcing over a larger region. Seasonal changes in the direction and intensity of winds, along with a late-winter improvement in light conditions, may determine the timing of phytoplankton blooms and potentially modulate productivity cycles in the region. Depth-integrated gross primary production estimates were higher (0.4-3.8 g C m -2 d -1) in the productive season (October, February, and May), and lower (0.1-0.2 g C m -2 d -1) in the non-productive season (August). These seasonal changes were also reflected in community respiration and bacterioplankton production rates, which ranged, respectively, from 0.3 to 4.8 g C m -2 d -1 and 0.05 to 0.4 g C m -2 d -1 during the productive and non-productive seasons and from 0.05 to 0.6 g C m -2 d -1 and 0.05 to 0.2 g C m -2 d -1 during the same two periods. We found a strong, significant correlation between gross primary production and community respiration (Spearman, r=0.95; p100%, suggesting the use of allochthonous carbon sources by bacterioplankton when the levels of gross primary production are low. Low primary production rates were associated with a greater contribution of small cells to autotrophic biomass, highlighting the importance of small-sized plankton and bacteria for carbon cycling and fluxes during the less productive winter months. Fecal pellet sedimentation was minimal during this period, also suggesting that most of

Engineering Changes in Product Design - A Review

Science.gov (United States)

Karthik, K.; Janardhan Reddy, K., Dr

2016-09-01

Changes are fundamental to product development. Engineering changes are unavoidable and can arise at any phase of the product life cycle. The consideration of market requirements, customer/user feedbacks, manufacturing constraints, design innovations etc., turning them into viable products can be accomplished when product change is managed properly. In the early design cycle, informal changes are accepted. However, changes become formal when its complexity and cost increases, and as product matures. To maximize the market shares, manufacturers have to effectively and efficiently manage engineering changes by means of Configuration Control. The paper gives a broad overview about ‘Engineering Change Management’ (ECM) through configuration management and its implications in product design. The aim is to give an idea and understanding about the engineering changes in product design scenario to the new researchers. This paper elaborates the significant aspect of managing the engineering changes and the importance of ECM in a product life cycle.

The impact of global warming on seasonality of ocean primary production

Directory of Open Access Journals (Sweden)

S. Henson

2013-06-01

Full Text Available The seasonal cycle (i.e. phenology of oceanic primary production (PP is expected to change in response to climate warming. Here, we use output from 6 global biogeochemical models to examine the response in the seasonal amplitude of PP and timing of peak PP to the IPCC AR5 warming scenario. We also investigate whether trends in PP phenology may be more rapidly detectable than trends in annual mean PP. The seasonal amplitude of PP decreases by an average of 1–2% per year by 2100 in most biomes, with the exception of the Arctic which sees an increase of ~1% per year. This is accompanied by an advance in the timing of peak PP by ~0.5–1 months by 2100 over much of the globe, and particularly pronounced in the Arctic. These changes are driven by an increase in seasonal amplitude of sea surface temperature (where the maxima get hotter faster than the minima and a decrease in the seasonal amplitude of the mixed layer depth and surface nitrate concentration. Our results indicate a transformation of currently strongly seasonal (bloom forming regions, typically found at high latitudes, into weakly seasonal (non-bloom regions, characteristic of contemporary subtropical conditions. On average, 36 yr of data are needed to detect a climate-change-driven trend in the seasonal amplitude of PP, compared to 32 yr for mean annual PP. Monthly resolution model output is found to be inadequate for resolving phenological changes. We conclude that analysis of phytoplankton seasonality is not necessarily a shortcut to detecting climate change impacts on ocean productivity.

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

Science.gov (United States)

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.

Physical control of primary productivity on a seasonal scale in ...

Indian Academy of Sciences (India)

Keywords. Primary production; upwelling; winter cooling; Ekman-pumping, nutrient transport; Arabian Sea ... on the other hand, is driven by advection from the Somalia upwelling. Surface cooling and convection resulting from reduced solar radiation and increased evaporation make the northern region productive in winter.

Primary production measurements at three reservoirs in the state of Sao Paulo, Brazil

International Nuclear Information System (INIS)

Jureidini, P.; Chinez, S.J.; Agudo, E.G.

1983-01-01

Primary production measurements were carried out at three reservoirs in the state of Sao Paulo, Barra Bonita, Paiva Castro and Ponte nova using the 14 C technique. Meanwhile, several physical and chemical parameters of these water were also evaluated, in order to find out the limnological conditions of these reservoirs. Primary production rates ranged from 7,6mg C/m 3 d at Ponte Nova, to 247,2mg C/m 3 d at Barra Bonita. There seems to be god correlation between water quality data and primary production measurements. Regarding the results, it may be stated that the Barra Bonita reservoir has reached the eutrophic level, while the other two exibit mesotrophic levels. As a way of testing the water quality data collected was used in Churchill and Nicholas model, issuing results in agreement with those of the primary production measurements. (Author) [pt

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)

Ocular changes in primary hypothyroidism.

Science.gov (United States)

Ozturk, Banu T; Kerimoglu, Hurkan; Dikbas, Oguz; Pekel, Hamiyet; Gonen, Mustafa S

2009-12-29

To determine the ocular changes related to hypothyrodism in newly diagnosed patients without orbitopathy. Thirty-three patients diagnosed to have primary overt hypothyroidism were enrolled in the study. All subjects were assigned to underwent central corneal thickness (CCT), anterior chamber volume, depth and angle measurements with the Scheimpflug camera (Pentacam, Oculus) and cup to disc ratio (C/D), mean retinal thickness and mean retinal nerve fiber layer (RNFL) thickness measurements with optical coherence tomography (OCT) in addition to ophthalmological examination preceeding the replacement therapy and at the 1(st), 3(rd )and 6(th )months of treatment. The mean age of the patients included in the study were 40.58 +/- 1.32 years. The thyroid hormone levels return to normal levels in all patients during the follow-up period, however the mean intraocular pressure (IOP) revealed no significant change. The mean CCT was 538.05 +/- 3.85 mu initially and demonstrated no statistically significant change as the anterior chamber volume, depth and angle measurements did. The mean C/D ratio was 0.29 +/- 0.03 and the mean retinal thickness was 255.83 +/- 19.49 mu initially and the treatment did not give rise to any significant change. The mean RNFL thickness was also stable during the control visits, so no statistically significant change was encountered. Neither hypothyroidism, nor its replacement therapy gave rise to any change of IOP, CCT, anterior chamber parameters, RNFL, retinal thickness and C/D ratio.

Temperature dependence of CO2-enhanced primary production in the European Arctic Ocean

KAUST Repository

Holding, J. M.

2015-08-31

The Arctic Ocean is warming at two to three times the global rate1 and is perceived to be a bellwether for ocean acidification2, 3. Increased CO2 concentrations are expected to have a fertilization effect on marine autotrophs4, and higher temperatures should lead to increased rates of planktonic primary production5. Yet, simultaneous assessment of warming and increased CO2 on primary production in the Arctic has not been conducted. Here we test the expectation that CO2-enhanced gross primary production (GPP) may be temperature dependent, using data from several oceanographic cruises and experiments from both spring and summer in the European sector of the Arctic Ocean. Results confirm that CO2 enhances GPP (by a factor of up to ten) over a range of 145–2,099 μatm; however, the greatest effects are observed only at lower temperatures and are constrained by nutrient and light availability to the spring period. The temperature dependence of CO2-enhanced primary production has significant implications for metabolic balance in a warmer, CO2-enriched Arctic Ocean in the future. In particular, it indicates that a twofold increase in primary production during the spring is likely in the Arctic.

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.

HANPP Collection: Global Patterns in Net Primary Productivity (NPP)

Data.gov (United States)

National Aeronautics and Space Administration — The Global Patterns in Net Primary Productivity (NPP) portion of the HANPP Collection maps the net amount of solar energy converted to plant organic matter through...

Plant community, primary productivity, and environmental conditions following wetland re-establishment in the Sacramento-San Joaquin Delta, California

Science.gov (United States)

Miller, R.L.; Fujii, R.

2010-01-01

Wetland restoration can mitigate aerobic decomposition of subsided organic soils, as well as re-establish conditions favorable for carbon storage. Rates of carbon storage result from the balance of inputs and losses, both of which are affected by wetland hydrology. We followed the effect of water depth (25 and 55 cm) on the plant community, primary production, and changes in two re-established wetlands in the Sacramento San-Joaquin River Delta, California for 9 years after flooding to determine how relatively small differences in water depth affect carbon storage rates over time. To estimate annual carbon inputs, plant species cover, standing above- and below-ground plant biomass, and annual biomass turnover rates were measured, and allometric biomass models for Schoenoplectus (Scirpus) acutus and Typha spp., the emergent marsh dominants, were developed. As the wetlands developed, environmental factors, including water temperature, depth, and pH were measured. Emergent marsh vegetation colonized the shallow wetland more rapidly than the deeper wetland. This is important to potential carbon storage because emergent marsh vegetation is more productive, and less labile, than submerged and floating vegetation. Primary production of emergent marsh vegetation ranged from 1.3 to 3.2 kg of carbon per square meter annually; and, mid-season standing live biomass represented about half of the annual primary production. Changes in species composition occurred in both submerged and emergent plant communities as the wetlands matured. Water depth, temperature, and pH were lower in areas with emergent marsh vegetation compared to submerged vegetation, all of which, in turn, can affect carbon cycling and storage rates. ?? Springer Science+Business Media B.V. 2009.

Primary production in a tropical large lake: The role of phytoplankton composition

Energy Technology Data Exchange (ETDEWEB)

Darchambeau, F., E-mail: francois.darchambeau@ulg.ac.be [Chemical Oceanography Unit, University of Liège, Liège (Belgium); Sarmento, H., E-mail: hugo.sarmento@gmail.com [Department of Hydrobiology, Federal University of São Carlos, 13565-905 São Carlos, São Paulo (Brazil); Descy, J.-P., E-mail: jean-pierre.descy@unamur.be [Research Unit in Environmental and Evolutionary Biology, University of Namur, Namur (Belgium)

2014-03-01

Phytoplankton biomass and primary production in tropical large lakes vary at different time scales, from seasons to centuries. We provide a dataset made of 7 consecutive years of phytoplankton biomass and production in Lake Kivu (Eastern Africa). From 2002 to 2008, bi-weekly samplings were performed in a pelagic site in order to quantify phytoplankton composition and biomass, using marker pigments determined by HPLC. Primary production rates were estimated by 96 in situ {sup 14}C incubations. A principal component analysis showed that the main environmental gradient was linked to a seasonal variation of the phytoplankton assemblage, with a clear separation between diatoms during the dry season and cyanobacteria during the rainy season. A rather wide range of the maximum specific photosynthetic rate (P{sub Bm}) was found, ranging between 1.15 and 7.21 g carbon g{sup −1} chlorophyll a h{sup −1}, and was best predicted by a regression model using phytoplankton composition as an explanatory variable. The irradiance at the onset of light saturation (I{sub k}) ranged between 91 and 752 μE m{sup −2} s{sup −1} and was linearly correlated with the mean irradiance in the mixed layer. The inter-annual variability of phytoplankton biomass and production was high, ranging from 53 to 100 mg chlorophyll a m{sup −2} (annual mean) and from 143 to 278 g carbon m{sup −2} y{sup −1}, respectively. The degree of seasonal mixing determined annual production, demonstrating the sensitivity of tropical lakes to climate variability. A review of primary production of other African great lakes allows situating Lake Kivu productivity in the same range as that of lakes Tanganyika and Malawi, even if mean phytoplankton biomass was higher in Lake Kivu. - Highlights: • We provide a 7-year dataset of primary production in a tropical great lake. • Specific photosynthetic rate was determined by community composition. • Annual primary production varied between 143 and 278 mg C m

Fission product behaviour in the primary circuit of an HTR

International Nuclear Information System (INIS)

Decken, C.B. von der; Iniotakis, N.

1981-01-01

The knowledge of fission product behaviour in the primary circuit of a High Temperature Reactor (HTR) is an essential requirement for the estimations of the availability of the reactor plant in normal operation, of the hazards to personnel during inspection and repair and of the potential danger to the environment from severe accidents. On the basis of the theoretical and experimental results obtained at the ''Institute for Reactor Components'' of the KFA Juelich /1/,/2/ the transport- and deposition behaviour of the fission- and activation products in the primary circuit of the PNP-500 reference plant has been investigated thoroughly. Special work had been done to quantify the uncertainties of the investigations and to calculate or estimate the dose rate level at different components of the primary cooling circuit. The contamination and the dose rate level in the inspection gap in the reactor pressure vessel is discussed in detail. For these investigations in particular the surface structure and the composition of the material, the chemical state of the fission products in the cooling gas, the composition of the cooling gas and the influence of dust on the transport- and deposition behaviour of the fission products have been taken into account. The investigations have been limited to the nuclides Ag-110m; Cs-134 and Cs-137

A multi-sites analysis on the ozone effects on Gross Primary Production of European forests

Energy Technology Data Exchange (ETDEWEB)

Proietti, C. [Department of Environmental Biology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome (Italy); Anav, A. [Italian National Agency for New Technologies, Energy and the Environment (ENEA), C.R. Casaccia, Via Anguillarese 301, 00123 S. Maria di Galeria, Rome (Italy); University of Exeter, College of Engineering, Mathematics and Physical Sciences, Exeter (United Kingdom); De Marco, A. [Italian National Agency for New Technologies, Energy and the Environment (ENEA), C.R. Casaccia, Via Anguillarese 301, 00123 S. Maria di Galeria, Rome (Italy); Sicard, P. [ACRI-HE, 260 route du Pin Montard BP234, 06904 Sophia Antipolis-cedex (France); Vitale, M., E-mail: marcello.vitale@uniroma1.it [Department of Environmental Biology, Sapienza University of Rome, Piazzale Aldo Moro, 5, 00185 Rome (Italy)

2016-06-15

Ozone (O{sub 3}) is both a greenhouse gas and a secondary air pollutant causing adverse impacts on forests ecosystems at different scales, from cellular to ecosystem level. Specifically, the phytotoxic nature of O{sub 3} can impair CO{sub 2} assimilation that, in turn affects forest productivity. This study aims to evaluate the effects of tropospheric O{sub 3} on Gross Primary Production (GPP) at 37 European forest sites during the time period 2000–2010. Due to the lack of carbon assimilation data at O{sub 3} monitoring stations (and vice-versa) this study makes a first attempt to combine high resolution MODIS Gross Primary Production (GPP) estimates and O{sub 3} measurement data. Partial Correlations, Anomalies Analysis and the Random Forests Analysis (RFA) were used to quantify the effects of tropospheric O{sub 3} concentration and its uptake on GPP and to evaluate the most important factors affecting inter-annual GPP changes. Our results showed, along a North-West/South-East European transect, a negative impact of O{sub 3} on GPP ranging from 0.4% to 30%, although a key role of meteorological parameters respect to pollutant variables in affecting GPP was found. In particular, meteorological parameters, namely air temperature (T), soil water content (SWC) and relative humidity (RH) are the most important predictors at 81% of test sites. Moreover, it is interesting to highlight a key role of SWC in the Mediterranean areas (Spanish, Italian and French test sites) confirming that, soil moisture and soil water availability affect vegetation growth and photosynthesis especially in arid or semi-arid ecosystems such as the Mediterranean climate regions. Considering the pivotal role of GPP in the global carbon balance and the O{sub 3} ability to reduce primary productivity of the forests, this study can help in assessing the O{sub 3} impacts on ecosystem services, including wood production and carbon sequestration. - Highlights: • Assessment of the surface O{sub 3

Ocular changes in primary hypothyroidism

Directory of Open Access Journals (Sweden)

Pekel Hamiyet

2009-12-01

Full Text Available Abstract Background To determine the ocular changes related to hypothyrodism in newly diagnosed patients without orbitopathy. Findings Thirty-three patients diagnosed to have primary overt hypothyroidism were enrolled in the study. All subjects were assigned to underwent central corneal thickness (CCT, anterior chamber volume, depth and angle measurements with the Scheimpflug camera (Pentacam, Oculus and cup to disc ratio (C/D, mean retinal thickness and mean retinal nerve fiber layer (RNFL thickness measurements with optical coherence tomography (OCT in addition to ophthalmological examination preceeding the replacement therapy and at the 1st, 3rd and 6th months of treatment. The mean age of the patients included in the study were 40.58 ± 1.32 years. The thyroid hormone levels return to normal levels in all patients during the follow-up period, however the mean intraocular pressure (IOP revealed no significant change. The mean CCT was 538.05 ± 3.85 μ initially and demonstrated no statistically significant change as the anterior chamber volume, depth and angle measurements did. The mean C/D ratio was 0.29 ± 0.03 and the mean retinal thickness was 255.83 ± 19.49 μ initially and the treatment did not give rise to any significant change. The mean RNFL thickness was also stable during the control visits, so no statistically significant change was encountered. Conclusions Neither hypothyroidism, nor its replacement therapy gave rise to any change of IOP, CCT, anterior chamber parameters, RNFL, retinal thickness and C/D ratio.

Responses of primary production, leaf litter decomposition and associated communities to stream eutrophication

International Nuclear Information System (INIS)

Dunck, Bárbara; Lima-Fernandes, Eva; Cássio, Fernanda; Cunha, Ana; Rodrigues, Liliana; Pascoal, Cláudia

2015-01-01

We assessed the eutrophication effects on leaf litter decomposition and primary production, and on periphytic algae, fungi and invertebrates. According to the subsidy-stress model, we expected that when algae and decomposers were nutrient limited, their activity and diversity would increase at moderate levels of nutrient enrichment, but decrease at high levels of nutrients, because eutrophication would lead to the presence of other stressors and overwhelm the subsidy effect. Chestnut leaves (Castanea sativa Mill) were enclosed in mesh bags and immersed in five streams of the Ave River basin (northwest Portugal) to assess leaf decomposition and colonization by invertebrates and fungi. In parallel, polyethylene slides were attached to the mesh bags to allow colonization by algae and to assess primary production. Communities of periphytic algae and decomposers discriminated the streams according to the trophic state. Primary production decomposition and biodiversity were lower in streams at both ends of the trophic gradient. - Highlights: • Algae and decomposers discriminated the streams according to the eutrophication level. • Primary production and litter decomposition are stimulated by moderate eutrophication. • Biodiversity and process rates were reduced in highly eutrophic streams. • Subsidy-stress model explained biodiversity and process rates under eutrophication. - Rates of leaf litter decomposition, primary production and richness of periphytic algae, fungi and invertebrates were lower in streams at both ends of the trophic gradient

Molecular biology in studies of oceanic primary production

International Nuclear Information System (INIS)

LaRoche, J.; Falkowski, P.G.; Geider, R.

1992-01-01

Remote sensing and the use of moored in situ instrumentation has greatly improved our ability to measure phytoplankton chlorophyll and photosynthesis on global scales with high temporal resolution. However, the interpretation of these measurements and their significance with respect to the biogeochemical cycling of carbon relies on their relationship with physiological and biochemical processes in phytoplankton. For example, the use of satellite images of surface chlorophyll to estimate primary production is often based on the functional relationship between photosynthesis and irradiance. A variety of environmental factors such as light, temperature, nutrient availability affect the photosynthesis/irradiance (P vs I) relationship in phytoplankton. We present three examples showing how molecular biology can be used to provide basic insight into the factors controlling primary productivity at three different levels of complexity: 1. Studies of light intensity regulation in unicellular alga show how molecular biology can help understand the processing of environmental cues leading to the regulation of photosynthetic gene expression. 2. Probing of the photosynthetic apparatus using molecular techniques can be used to test existing mechanistic models derived from the interpretation of physiological and biophysical measurements. 3. Exploratory work on the expression of specific proteins during nutrient-limited growth of phytoplankton may lead to the identification and production of molecular probes for field studies

Hydrogen Production Costs of Various Primary Energy Sources

International Nuclear Information System (INIS)

Choi, Jae Hyuk; Tak, Nam Il; Kim, Yong Hee; Park, Won Seok

2005-11-01

Many studies on the economical aspects of hydrogen energy technologies have been conducted with the increase of the technical and socioeconomic importance of the hydrogen energy. However, there is still no research which evaluates the economy of hydrogen production from the primary energy sources in consideration of Korean situations. In this study, the hydrogen production costs of major primary energy sources are compared in consideration of the Korean situations such as feedstock price, electricity rate, and load factor. The evaluation methodology is based on the report of the National Academy of Science (NAS) of U.S. The present study focuses on the possible future technology scenario defined by NAS. The scenario assumes technological improvement that may be achieved if present research and development (R and D) programs are successful. The production costs by the coal and natural gas are 1.1 $/kgH 2 and 1.36 $/kgH 2 , respectively. However, the fossil fuels are susceptible to the price variation depending on the oil and the raw material prices, and the hydrogen production cost also depends on the carbon tax. The economic competitiveness of the renewable energy sources such as the wind, solar, and biomass are relatively low when compared with that of the other energy sources. The estimated hydrogen production costs from the renewable energy sources range from 2.35 $/kgH 2 to 6.03 $/kgH 2 . On the other hand, the production cost by nuclear energy is lower than that of natural gas or coal when the prices of the oil and soft coal are above $50/barrel and 138 $/ton, respectively. Taking into consideration the recent rapid increase of the oil and soft coal prices and the limited fossil resource, the nuclear-hydrogen option appears to be the most economical way in the future

Denali Ice Core MSA: A Record of North Pacific Primary Productivity

Science.gov (United States)

Polashenski, D.; Osterberg, E. C.; Winski, D.; Kreutz, K. J.; Wake, C. P.; Ferris, D. G.; Introne, D.; Campbell, S. W.

2017-12-01

The high nutrient, low chlorophyll region of the North Pacific is one of the most biologically productive marine ecosystems in the world and forms the basis of commercial, sport, and subsistence fisheries worth more than a billion dollars annually. Marine phytoplankton prove to be important both as the primary producers in these ecosystems and as a major source of biogenic sulfur emissions which have long been hypothesized to serve as a biological control on Earth's climate system. Despite their importance, the record of marine phytoplankton abundance and the flux of biogenic sulfur from these regions is not well constrained. In situ measurements of marine phytoplankton from oceanographic cruises over the past several decades are limited in both spatial and temporal resolution. Meanwhile, marine sediment records may provide insight on million year timescales, but lack decadal resolution due to slow sediment deposition rates and bioturbation. In this study, we aim to investigate changes in marine phytoplankton productivity of the northeastern subarctic Pacific Ocean (NSPO) over the twentieth century using the methanesulfonic acid (MSA) record from the Mt. Hunter ice cores drilled in Denali National Park, Alaska. These parallel, 208 meter long ice cores were drilled during the 2013 field season on the Mt. Hunter plateau (63° N, 151° W, 4,000 m above sea level). Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) modeling is used to identify likely source areas in the NSPO for MSA being transported to the core site. SeaWiFS satellite imagery allows for a direct comparison of chlorophyll a concentrations in these source areas with MSA concentrations in the core record through time. Our findings suggest that the Denali ice core MSA record reflects changes in the biological productivity of marine phytoplankton and shows a significant decline in MSA beginning in 1961. We investigate several hypotheses for potential mechanisms driving this MSA decline

UV radiation and primary production in the Antarctic waters

Digital Repository Service at National Institute of Oceanography (India)

LokaBharathi, P.A.; Krishnakumari, L.; Bhattathiri, P.M.A.; Chandramohan, D.

at 683 nm), scalar irradiance (photosynthetically active radiation (PAR), computed primary production (pp), diffuse attenuation coefficient, and UVB (308 and 320 nm) and UVA (340 and 380 nm) radiation and ocean temperature all measured as a function...

Regulation of primary productivity rate in the equatorial Pacific

International Nuclear Information System (INIS)

Barber, R.T.; Chavez, F.P.

1991-01-01

Analysis of the Chl-specific rate of primary productivity (P B ) as a function of subsurface nutrient concentration at >300 equatorial stations provides an answer to the question: What processes regulate primary productivity rate in the high-nutrient, low-chlorophyll waters of the equatorial Pacific? In the western Pacific where there is a gradient in 60-m [NO 3 ] from 0 to ∼12 μM, the productivity rate is a linear function of nutrient concentration; in the eastern Pacific where the gradient is from 12 to 28 μM, the productivity rate is independent of nutrient concentration and limited to ∼36 mg C(mg Chl) -1 d -1 , or a mean euphotic zone C-specific growth rate (μ) of 0.47 d -1 . However, rates downstream of the Galapagos Islands are not limited; they are 46.4 mg C(mg Chl) -1 d -1 and μ = 0.57 d -1 , very close to the predicted nutrient-regulated rates in the absence of other limitation. This pattern of rate regulation can be accounted for by a combination of eolian Fe, subsurface nutrients, and sedimentary Fe derived from the Galapagos platform. In the low-nutrient western Pacific the eolian supply of Fe is adequate to allow productivity rate to be set by subsurface nutrient concentration. In the nutrient-rich easter equatorial region eolian Fe is inadequate to support productivity rates proportional to the higher nutrient concentrations, so in this region eolian Fe is rate limiting. Around the Galapagos Islands productivity rates reach levels consistent with nutrient concentrations; sedimentary Fe from the Galapagos platform seems adequate to support increased nutrient-regulated productivity rates in this region

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

Regionally and seasonally differentiated primary production in the North Atlantic

Science.gov (United States)

Sathyendranath, Shubha; Longhurst, Alan; Caverhill, Carla M.; Platt, Trevor

1995-10-01

A bio-geochemical classification of the N. Atlantic Basin is presented according to which the basin is first divided into four primary algal domains: Polar, West-Wind, Trades and Coastal. These are in turn sub-divided into smaller provinces. The classification is based on differences in the physical environment which are likely to influence regional algal dynamics. The seasonally-differentiated parameters of the photosynthesis-light curve ( P-I curve) and parameters that define the vertical structure in chlorophyll profile are then established for each province, based on an analysis of an archive of over 6000 chlorophyll profiles, and over 1800 P-I curves. These are then combined with satellite-derived chlorophyll data for the N. Atlantic, and information on cloud cover, to compute primary production at the annual scale. using a model that computes spectral transmission of light underwater, and spectral, photosynthetic response of phytoplankton to available light. The results are compared with earlier, satellite-derived, estimates of basin-scale primary production.

Exploring the response of net primary productivity variations to urban expansion and climate change: a scenario analysis for Guangdong Province in China.

Science.gov (United States)

Pei, Fengsong; Li, Xia; Liu, Xiaoping; Lao, Chunhua; Xia, Gengrui

2015-03-01

Urban land development alters landscapes and carbon cycle, especially net primary productivity (NPP). Despite projections that NPP is often reduced by urbanization, little is known about NPP changes under future urban expansion and climate change conditions. In this paper, terrestrial NPP was calculated by using Biome-BGC model. However, this model does not explicitly address urban lands. Hence, we proposed a method of NPP-fraction to detect future urban NPP, assuming that the ratio of real NPP to potential NPP for urban cells remains constant for decades. Furthermore, NPP dynamics were explored by integrating the Biome-BGC and the cellular automata (CA), a widely used method for modeling urban growth. Consequently, urban expansion, climate change and their associated effects on the NPP were analyzed for the period of 2010-2039 using Guangdong Province in China as a case study. In addition, four scenarios were designed to reflect future conditions, namely baseline, climate change, urban expansion and comprehensive scenarios. Our analyses indicate that vegetation NPP in urban cells may increase (17.63 gC m(-2) year(-1)-23.35 gC m(-2) year(-1)) in the climate change scenario. However, future urban expansion may cause some NPP losses of 241.61 gC m(-2) year(-1), decupling the NPP increase of the climate change factor. Taking into account both climate change and urban expansion, vegetation NPP in urban area may decrease, minimally at a rate of 228.54 gC m(-2) year(-1) to 231.74 gC m(-2) year(-1). Nevertheless, they may account for an overall NPP increase of 0.78 TgC year(-1) to 1.28 TgC year(-1) in the whole province. All these show that the provincial NPP increase from climate change may offset the NPP decrease from urban expansion. Despite these results, it is of great significance to regulate reasonable expansion of urban lands to maintain carbon balance. Copyright © 2014 Elsevier Ltd. All rights reserved.

Three-dimensional space changes after premature loss of a maxillary primary first molar.

Science.gov (United States)

Park, Kitae; Jung, Da-Woon; Kim, Ji-Yeon

2009-11-01

A space maintainer is generally preferred when a primary first molar is lost before or during active eruption of the first permanent molars in order to prevent space loss. However, controversy prevails regarding the space loss after eruption of the permanent first molars. The purpose of this study was to examine spatial changes subsequent to premature loss of a maxillary primary first molar after the eruption of the permanent first molars. Thirteen children, five girls and eight boys, expecting premature extraction of a maxillary primary first molar because of caries and/or failed pulp therapy, were selected. Spatial changes were investigated using a three-dimensional laser scanner by comparing the primary molar space, arch width, arch length, and arch perimeter before and after the extraction of a maxillary primary first molar. Also, the inclination and angulation changes in the maxillary primary canines, primary second molars, and permanent first molars adjacent to the extraction site were investigated before and after the extraction of the maxillary primary first molar in order to examine the source of space loss. There was no statistically significant space loss on the extraction side compared to the control side (P = 0.33). No consistent findings were seen on the inclination and angulation changes on the extraction side. The premature loss of a maxillary primary first molar, in cases with class I molar relationship, has limited influence on the space in permanent dentition.

Climate change impacts on natural toxins in food production systems, exemplified by deoxynivalenol in wheat and diarrhetic shellfish toxins

NARCIS (Netherlands)

Fels-Klerx, van der H.J.; Olesen, J.E.; Naustvoll, L.J.; Friocourt, Y.; Mengelers, M.J.B.; Christensen, J.H.

2012-01-01

Climate change is expected to affect food and feed safety, including the occurrence of natural toxins in primary crop and seafood production; however, to date, quantitative estimates are scarce. This study aimed to estimate the impact of climate change effects on mycotoxin contamination of cereal

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.

Propagation of engineering changes to multiple product data views using history of product structure changes

NARCIS (Netherlands)

Do, N.; Choi, I.; Song, M.S.

2008-01-01

Abstract The present paper proposes a comprehensive procedure for engineering change propagation in order to maintain consistency between various product data views. A product data model is also proposed for the propagation procedure, which integrates base product definitions for product design, and

IR laser induced reactions: temperature distributions and detection of primary products

International Nuclear Information System (INIS)

Bachmann, F.

1981-12-01

The products of laser-driven pyrolysis in the gas phase often differ drastically from those of conventional pyrolysis. In this work some reasons for this behaviour are considered. First, temperature distributions in cylindrical cells, filled with SF 6 at low pressure and heated by cw CO 2 laser radiation, are calculated by a simple model. The influence of convection is not taken into account. Comparison of theoretical prediction and corresponding experiments included the temperature-dependent absorption cross section. In the second part we describe a molecular-beam sampling system for real time monitoring of primary products in laser-driven reactions. With this system initial tests were made in nonreacting SF 6 /rare-gas mixtures. The influence of thermal diffusion was indicated by changes in concentration when the laser was switched on and off. A theoretical treatment is given solving the time-dependent heat-conduction and diffusion equation numerically. As an example for reacting systems, the laser-driven pyrolysis of methanol with SF 6 as an absorber was studied. (orig./HT)

Patterns of new versus recycled primary production in the terrestrial biosphere

Science.gov (United States)

Nitrogen (N) and phosphorus (P) availability regulate plant productivity throughout the terrestrial biosphere, influencing the patterns and magnitude of net primary production (NPP) by land plants both now and into the future. These nutrients enter ecosystems via geologic and atmospheric pathways, a...

Benthic reef primary production in response to large amplitude internal waves at the Similan Islands (Andaman Sea, Thailand)

KAUST Repository

Jantzen, Carin

2013-11-29

Coral reefs are facing rapidly changing environments, but implications for reef ecosystem functioning and important services, such as productivity, are difficult to predict. Comparative investigations on coral reefs that are naturally exposed to differing environmental settings can provide essential information in this context. One prevalent phenomenon regularly introducing alterations in water chemistry into coral reefs are internal waves. This study therefore investigates the effect of large amplitude internal waves (LAIW) on primary productivity in coral reefs at the Similan Islands (Andaman Sea, Thailand). The LAIW-exposed west sides of the islands are subjected to sudden drops in water temperature accompanied by enhanced inorganic nutrient concentrations compared to the sheltered east. At the central island, Ko Miang, east and west reefs are only few hundred meters apart, but feature pronounced differences. On the west lower live coral cover (-38%) coincides with higher turf algae cover (+64%) and growth (+54%) compared to the east side. Turf algae and the reef sand-associated microphytobenthos displayed similar chlorophyll a contents on both island sides, but under LAIW exposure, turf algae exhibited higher net photosynthesis (+23%), whereas the microphytobenthos displayed reduced net and gross photosynthesis (-19% and -26%, respectively) accompanied by lower respiration (-42%). In contrast, the predominant coral Porites lutea showed higher chlorophyll a tissues contents (+42%) on the LAIW-exposed west in response to lower light availability and higher inorganic nutrient concentrations, but net photosynthesis was comparable for both sides. Turf algae were the major primary producers on the west side, whereas microphytobenthos dominated on the east. The overall primary production rate (comprising all main benthic primary producers) was similar on both island sides, which indicates high primary production variability under different environmental conditions. �

Implementing change in primary care practices using electronic medical records: a conceptual framework.

Science.gov (United States)

Nemeth, Lynne S; Feifer, Chris; Stuart, Gail W; Ornstein, Steven M

2008-01-16

Implementing change in primary care is difficult, and little practical guidance is available to assist small primary care practices. Methods to structure care and develop new roles are often needed to implement an evidence-based practice that improves care. This study explored the process of change used to implement clinical guidelines for primary and secondary prevention of cardiovascular disease in primary care practices that used a common electronic medical record (EMR). Multiple conceptual frameworks informed the design of this study designed to explain the complex phenomena of implementing change in primary care practice. Qualitative methods were used to examine the processes of change that practice members used to implement the guidelines. Purposive sampling in eight primary care practices within the Practice Partner Research Network-Translating Researching into Practice (PPRNet-TRIP II) clinical trial yielded 28 staff members and clinicians who were interviewed regarding how change in practice occurred while implementing clinical guidelines for primary and secondary prevention of cardiovascular disease and strokes. A conceptual framework for implementing clinical guidelines into primary care practice was developed through this research. Seven concepts and their relationships were modelled within this framework: leaders setting a vision with clear goals for staff to embrace; involving the team to enable the goals and vision for the practice to be achieved; enhancing communication systems to reinforce goals for patient care; developing the team to enable the staff to contribute toward practice improvement; taking small steps, encouraging practices' tests of small changes in practice; assimilating the electronic medical record to maximize clinical effectiveness, enhancing practices' use of the electronic tool they have invested in for patient care improvement; and providing feedback within a culture of improvement, leading to an iterative cycle of goal setting

Primary production in the Bay of Bengal during southwest monsoon of 1978

Digital Repository Service at National Institute of Oceanography (India)

Bhattathiri, P.M.A.; Devassy, V.P.; Radhakrishna, K.

Measurements of primary production, chlorophyll a and particulate organic carbon were made at 33, 43 and 44 stations respectively during August-September of 1978. The average surface production, chlorophyll a and particulate organic carbon values...

Attributing regional trends of evapotranspiration and gross primary productivity with remote sensing: a case study in the North China Plain

Science.gov (United States)

Mo, Xingguo; Chen, Xuejuan; Hu, Shi; Liu, Suxia; Xia, Jun

2017-01-01

Attributing changes in evapotranspiration (ET) and gross primary productivity (GPP) is crucial for impact and adaptation assessment of the agro-ecosystems to climate change. Simulations with the VIP model revealed that annual ET and GPP slightly increased from 1981 to 2013 over the North China Plain. The tendencies of both ET and GPP were upward in the spring season, while they were weak and downward in the summer season. A complete factor analysis illustrated that the relative contributions of climatic change, CO2 fertilization, and management to the ET (GPP) trend were 56 (-32) %, -28 (25) %, and 68 (108) %, respectively. The decline of global radiation resulted from deteriorated aerosol and air pollution was the principal cause of GPP decline in summer, while air warming intensified the water cycle and advanced the plant productivity in the spring season. Generally, agronomic improvements were the principal drivers of crop productivity enhancement.

Primary Productivity, SeaWiFS and Pathfinder, 0.1 degrees, Global, EXPERIMENTAL

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Primary Productivity is calculated from SeaWiFS Chl a, Pathfinder SST, and SeaWiFS PAR data. THIS IS AN EXPERIMENTAL PRODUCT: intended strictly for scientific...

Climate change and broadacre livestock production across southern Australia. 1. Impacts of climate change on pasture and livestock productivity, and on sustainable levels of profitability.

Science.gov (United States)

Moore, Andrew D; Ghahramani, Afshin

2013-05-01

Broadacre livestock production is a major but highly diverse component of agriculture in Australia that will be significantly exposed to predicted changes in climate over coming decades. We used the GRAZPLAN simulation models to assess the impacts of climate change under the SRES A2 scenario across southern Australia. Climate change impacts were examined across space (25 representative locations) and time (1970-99, 2030, 2050 and 2070 climate) for each of five livestock enterprises. Climate projection uncertainty was considered by analysing projections from four global circulation models (GCMs). Livestock production scenarios were compared at their profit-maximizing stocking rate, constrained to ensure that risks of soil erosion were acceptable. Impacts on net primary productivity (ANPP) varied widely between GCM projections; the average declines from historical climate were 9% in 2030, 7% in 2050 and 14% in 2070. Declines in ANPP were larger at lower-rainfall locations. Sensitivity of ANPP to changes in rainfall ranged from 0.4 to 1.7, to temperature increase from -0.15 to +0.07 °C(-1) and to CO2 increase from 0.11 to 0.32. At most locations the dry summer period lengthened, exacerbating the greater erosion risk due to lower ANPP. Transpiration efficiency of pastures increased by 6-25%, but the proportion of ANPP that could safely be consumed by livestock fell sharply so that operating profit (at constant prices) fell by an average of 27% in 2030, 32% in 2050 and 48% in 2070. This amplification of ANPP reductions into larger profitability declines is likely to generalize to other extensive livestock systems. Profit declines were most marked at drier locations, with operating losses expected at 9 of the 25 locations by 2070. Differences between livestock enterprises were smaller than differences between locations and dates. Future research into climate change impacts on Australian livestock production needs to emphasise the dry margin of the cereal-livestock zone

Anoxic and oxic phototrophic primary production during the Precambrian

DEFF Research Database (Denmark)

Ebey-Honeycutt, Christina Marie; Bjerrum, Christian J.; Canfield, Donald Eugene

2009-01-01

of the mixed layer often lies above the base of the photic zone . Thus, an ecosystem model for the Precambrian should reflect the net primary production (NPP) of oxygenic phototrophs in the mixed layer and anoxygenic phototrophs below (NPPox and NPPred, respectively). Satelite data and a vertically generalized...

Interview and questionnaire guide: Quantification of food losses and waste in primary production

DEFF Research Database (Denmark)

Svanes, Erik; Hartikainen, Hanna; Mogensen, Lisbeth

production in the Nordic countries. Other aims were to estimate the amount of side flow and to gain knowledge about the reasons behind it, how it can be reduced, how it is treated and how it can be better utilized.This guide contains a catalogue of questions that may be used for interviews and questionnaires...... with primary producers and other stakeholders within primary production. It also contains the justification behind the questions and some tips on how to conduct interviews.......This interview guide was developed within the Nordic project “Food losses and waste in primary production” (Franke et al. 2016). One of the main purposes of the project was to test research methods for the quantification of food losses and waste (in the project called 'side flow') from primary...

Effect of the fast pyrolysis temperature on the primary and secondary products of lignin

NARCIS (Netherlands)

Zhou, Shuai; Garcia-Perez, Manuel; Pecha, Brennan; Kersten, Sascha R.A.; McDonald, Armando G.; Westerhof, Roel Johannes Maria

2013-01-01

This paper presents results on the primary pyrolysis products of organosolv lignin at temperatures between 360 and 700 °C. To study the primary products, a vacuum screen heater (heating rate of 8000 °C/s, deep vacuum of 0.7 mbar, and very fast cooling at the wall temperature of −100 °C) was used.

Productivity changes in OECD healthcare systems: bias-corrected Malmquist productivity approach.

Science.gov (United States)

Kim, Younhee; Oh, Dong-Hyun; Kang, Minah

2016-10-01

This study evaluates productivity changes in the healthcare systems of 30 Organization for Economic Co-operation and Development (OECD) countries over the 2002-2012 periods. The bootstrapped Malmquist approach is used to estimate bias-corrected indices of healthcare performance in productivity, efficiency and technology by modifying the original distance functions. Two inputs (health expenditure and school life expectancy) and two outputs (life expectancy at birth and infant mortality rate) are used to calculate productivity growth. There are no perceptible trends in productivity changes over the 2002-2012 periods, but positive productivity improvement has been noticed for most OECD countries. The result also informs considerable variations in annual productivity scores across the countries. Average annual productivity growth is evenly yielded by efficiency and technical changes, but both changes run somewhat differently across the years. The results of this study assert that policy reforms in OECD countries have improved productivity growth in healthcare systems over the past decade. Countries that lag behind in productivity growth should benchmark peer countries' practices to increase performance by prioritizing an achievable trajectory based on socioeconomic conditions. For example, relatively inefficient countries in this study indicate higher income inequality, corresponding to inequality and health outcomes studies. Although income inequality and globalization are not direct measures to estimate healthcare productivity in this study, these issues could be latent factors to explain cross-country healthcare productivity for future research. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Resources changes: a key factor in a new uranium production economic cycle

International Nuclear Information System (INIS)

Capus, G.; Caumartin, P.

1996-01-01

Since the end of 1994, a change has been underway in the uranium market. As usual in such cases, surprise and disbelief first dominated, but the market actors have been adjusting quickly to what now appears to be a return to primary production as the predominant factor in uranium supply. It is a matter of fact that the fundamentals will determine the course of the uranium market, as with other cyclical commodity markets. Comparing 1995 with 1975, a time of rocketing prices and production, and forecasting another cycle with similar characteristics to the last one is tempting, but illusory. However, examining the relative conditions prevailing at these times provides keys that may be helpful in understanding future developments. (author)

Palaeoceanographic controls on geochemical characteristics of organic-rich Exshaw mudrocks: role of enhanced primary production

Energy Technology Data Exchange (ETDEWEB)

Caplan, M.L.; Bustin, R.M. [University of British Columbia, Vancouver (Canada). Dept. of Earth and Ocean Sciences

1999-07-01

Organic-rich source rocks have generally been attributed to enhanced preservation of organic matter under anoxic bottom waters. Here geochemical analysis of kerogen and whole rock samples of organic-rich (lithofacies B{sub 1}) and organic-lean (lithofacies B{sub 2}) laminated mudrocks of the Devonian-Carboniferous Exshaw Formation, Alberta, highlight the importance of primary production in governing the quantity and quality of organic matter. Lower Si/Al, K/Al, Ti/Al and quartz/clay ratios in lithofacies B{sub 2}, similar maceral types and the laminated fabric of the two lithofacies indicate that the quality and quantity of organic matter are not related to grain size, redox or organic matter source changes. High Total Organic Carbon (TOC) and Hydrogen Index (HI), low Oxidation Index (Ox.I. ratio of oxygen functional groups to aliphatic groups derived by FTIR), lighter {delta}{sup 15}N{sub tot} and heavier {delta}{sup 13}C{sub org} isotopes indicate that kerogen of lithofacies B{sub 1} accumulated during periods of high organic-carbon production and delivery of relatively fresh, labile, well-preserved organic matter to the sea floor. In contrast, low TOC, HI, high Ox.I., heavier {delta}{sup 15}N{sub tot} and lighter {delta}{sup 13}C{sub org} isotopes indicate low primary productivity and delivery, high recycling and poor preservation of organic matter during accumulation of lithofacies B{sub 2}. (author)

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.

Primary production, nutrient dynamics and mineralisation in a northeastern Greenland fjord during the summer thaw

DEFF Research Database (Denmark)

Rysgaard, S.; Finster, K.; Dahlgaard, H.

1996-01-01

This investigation represents the first integrated study of primary production, nutrient dynamics and mineralisation in a northeastern fjord of Greenland. The data presented represent conditions and activities during the early summer thaw (first 2 weeks of July). Primary production (5.3 mmol C m(...

Interactions between atmospheric circulation, nutrient deposition, and tropical forest primary production (Invited)

Science.gov (United States)

Randerson, J. T.; Chen, Y.; Rogers, B. M.; Morton, D. C.; van der Werf, G.; Mahowald, N. M.

2010-12-01

Tropical forests influence regional and global climate by means of several pathways, including by modifying surface energy exchange and by forming clouds. High levels of precipitation, leaching, and soil weathering limit nutrient availability in these ecosystems. Phosphorus (P) is a key element limiting net primary production, and in some areas, including forests recovering from prior disturbance, nitrogen (N) also may limit some components of production. Here we quantified atmospheric P and N inputs to these forests from fires using satellite-derived estimates of emissions and atmospheric models. In Africa and South America, cross-biome transport of fire-emitted aerosols and reactive N gases from savannas and areas near the deforestation frontier increased deposition of P and N in interior forests. Equatorward atmospheric transport during the dry (fire) season in one hemisphere was linked with surface winds moving toward the inter-tropical convergence zone (ITCZ) in the other hemisphere. Deposition levels were higher in tropical forests in Africa than in South America because of large savanna areas with high levels of fire emissions in both southern and northern Africa. We conclude by describing a potential feedback loop by which equatorward transport of fire emissions, dust, and spores sustains the productivity of tropical forests. We specifically assessed evidence that savanna-to-forest atmospheric transport of nutrients increases forest productivity, height, and rates of evapotranspiration (ET). In parallel, we examined the degree to which increases in ET and surface roughness in tropical forests have the potential to strengthen several components of the Hadley circulation, including deep convection, equatorward return flow (near the surface), and the intensity of seasonal drought in the subtropics (thereby increasing fires). These interactions are important for understanding biogeochemical - climate interactions on millennial timescales and for quantifying how

Combined constraints on global ocean primary production using observations and models

Science.gov (United States)

Buitenhuis, Erik T.; Hashioka, Taketo; Quéré, Corinne Le

2013-09-01

production is at the base of the marine food web and plays a central role for global biogeochemical cycles. Yet global ocean primary production is known to only a factor of 2, with previous estimates ranging from 38 to 65 Pg C yr-1 and no formal uncertainty analysis. Here, we present an improved global ocean biogeochemistry model that includes a mechanistic representation of photosynthesis and a new observational database of net primary production (NPP) in the ocean. We combine the model and observations to constrain particulate NPP in the ocean with statistical metrics. The PlankTOM5.3 model includes a new photosynthesis formulation with a dynamic representation of iron-light colimitation, which leads to a considerable improvement of the interannual variability of surface chlorophyll. The database includes a consistent set of 50,050 measurements of 14C primary production. The model best reproduces observations when global NPP is 58 ± 7 Pg C yr-1, with a most probable value of 56 Pg C yr-1. The most probable value is robust to the model used. The uncertainty represents 95% confidence intervals. It considers all random errors in the model and observations, but not potential biases in the observations. We show that tropical regions (23°S-23°N) contribute half of the global NPP, while NPPs in the Northern and Southern Hemispheres are approximately equal in spite of the larger ocean area in the South.

Micro-phytoplankton photosynthesis, primary production and potential export production in the Atlantic Ocean

Science.gov (United States)

Tilstone, Gavin H.; Lange, Priscila K.; Misra, Ankita; Brewin, Robert J. W.; Cain, Terry

2017-11-01

Micro-phytoplankton is the >20 μm component of the phytoplankton community and plays a major role in the global ocean carbon pump, through the sequestering of anthropogenic CO2 and export of organic carbon to the deep ocean. To evaluate the global impact of the marine carbon cycle, quantification of micro-phytoplankton primary production is paramount. In this paper we use both in situ data and a satellite model to estimate the contribution of micro-phytoplankton to total primary production (PP) in the Atlantic Ocean. From 1995 to 2013, 940 measurements of primary production were made at 258 sites on 23 Atlantic Meridional Transect Cruises from the United Kingdom to the South African or Patagonian Shelf. Micro-phytoplankton primary production was highest in the South Subtropical Convergence (SSTC ∼ 409 ± 720 mg C m-2 d-1), where it contributed between 38 % of the total PP, and was lowest in the North Atlantic Gyre province (NATL ∼ 37 ± 27 mg C m-2 d-1), where it represented 18 % of the total PP. Size-fractionated photosynthesis-irradiance (PE) parameters measured on AMT22 and 23 showed that micro-phytoplankton had the highest maximum photosynthetic rate (PmB) (∼5 mg C (mg Chl a)-1 h-1) followed by nano- (∼4 mg C (mg Chl a)-1 h-1) and pico- (∼2 mg C (mg Chl a)-1 h-1). The highest PmB was recorded in the NATL and lowest in the North Atlantic Drift Region (NADR) and South Atlantic Gyre (SATL). The PE parameters were used to parameterise a remote sensing model of size-fractionated PP, which explained 84 % of the micro-phytoplankton in situ PP variability with a regression slope close to 1. The model was applied to the SeaWiFS time series from 1998-2010, which illustrated that micro-phytoplankton PP remained constant in the NADR, NATL, Canary Current Coastal upwelling (CNRY), Eastern Tropical Atlantic (ETRA), Western Tropical Atlantic (WTRA) and SATL, but showed a gradual increase in the Benguela Upwelling zone (BENG) and South Subtropical Convergence (SSTC

Possibility Thinking and Social Change in Primary Schools

Science.gov (United States)

Craft, Anna Rachel; Chappell, Kerry Anne

2016-01-01

This paper reviews the nature of possibility thinking (PT) (transformation from what is to what might be, in everyday contexts for children and teachers) and reports on how PT manifested in two English primary schools engaged in social change. It identifies shared characteristics across the schools as well as unique ways in which PT manifested.…

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)

Aging changes in hormone production

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/004000.htm Aging changes in hormone production To use the sharing ... that produce hormones are controlled by other hormones. Aging also changes this process. For example, an endocrine ...

Failed surgery in primary hyperparathyroidism - what has changed with time.

Science.gov (United States)

Wirowski, D; Goretzki, P E; Schwarz, K; Lammers, B J; Dotzenrath, C; Röher, H-D

2013-06-01

Advanced preoperative imaging of parathyroid adenomas and intraoperative parathyroid hormone determination optimized the results in the surgical treatment of primary hyperparathyroidism patients. We asked, whether reasons for failure have changed during the last 25 years.We retrospectively analyzed operations for persistent primary hyperparathyroidism in our department between 2001 and 2011 (n=67), and compared these results to our experience between 1986 and 2001 (n=80).From 2001 to 2011, 765 primary hyperparathyroidism patients were operated on at our department. All but 4 patients were cured (761/765, 99.5%). 67 operations were performed for persistent primary hyperparathyroidism. Main reasons for failure were a misdiagnosed sporadic multiple gland disease in our own patients (18/29, 62.1%), and an undetected solitary adenoma in patients referred to us after -initial operation in another hospital (22/38, 57.9%) (statistically significant). From 1986 to 2001 (1 105 primary hyperparathyroidism patients), main indications for re-operation due to persistent disease were an undiagnosed sporadic multiple gland disease in our own patients (15/24, 62.5%), and a missed solitary adenoma in patients being operated on primarily somewhere else (38/56, 67.9%) (statistically significant).Comparing our experience in 147 patients with persistent primary hyperparathyroidism being operated on between 2001-2011 and 1986-2001, not much has changed with the modern armamentarium of improved preoperative imaging or intraoperative biochemical control. Whereas sporadic multiple gland disease was the most common reason for unsuccessful surgery in experienced hands, other units mainly failed due to an undetected solitary adenoma. Re-operations for persistent primary hyperparathyroidism performed by us were successful in 93.8% (2001-2011) and 96.0% (1986-2001), respectively. © J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York.

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...

Surgeons' efficiency change is a major determinant of their productivity change.

Science.gov (United States)

Nakata, Yoshinori; Watanabe, Yuichi; Narimatsu, Hiroto; Yoshimura, Tatsuya; Otake, Hiroshi; Sawa, Tomohiro

2016-05-09

Purpose - The sustainability of the Japanese healthcare system is in question because the government has had a huge fiscal debt. Despite an enormous effort to cut the deficit, our healthcare expenditure is increasing every year because of the rapidly aging population. One of the solutions for this problem is to improve the productivity of healthcare. The purpose of this paper is to determine the factors that change surgeons' productivity in one year. Design/methodology/approach - The authors collected data of all surgical procedures performed at Teikyo University Hospital from April 1 through September 30 in 2014 and 2015, and computed the surgeons' Malmquist index (MI), efficiency change (EC) and technical change (TC) using non-radial and non-oriented Malmquist model under the constant returns-to-scale assumptions. The authors then divided the surgeons into two groups; one whose productivity progressed and the other whose productivity regressed. These two groups were compared to identify factors that may influence their MI. Findings - The only significant difference between the two groups was ECs (p productivity change. The best way to improve surgeons' productivity may be to enhance their efficiency regardless of their surgical volume and personal backgrounds.

Behavior Change without Behavior Change Communication: Nudging Handwashing among Primary School Students in Bangladesh

OpenAIRE

Dreibelbis, Robert; Kroeger, Anne; Hossain, Kamal; Venkatesh, Mohini; Ram, Pavani K.

2016-01-01

Behavior change communication for improving handwashing with soap can be labor and resource intensive, yet quality results are difficult to achieve. Nudges are environmental cues engaging unconscious decision-making processes to prompt behavior change. In this proof-of-concept study, we developed an inexpensive set of nudges to encourage handwashing with soap after toilet use in two primary schools in rural Bangladesh. We completed direct observation of behaviors at baseline, after providing ...

Globalization, structural change, and productivity growth:

OpenAIRE

McMillan, Margaret; Rodrik, Dani

2012-01-01

Large gaps in labor productivity between the traditional and modern parts of the economy are a fundamental reality of developing societies. In this paper, we document these gaps and emphasize that labor flows from low-productivity activities to high-productivity activities are a key driver of development. Our results show that since 1990 structural change has been growth-reducing in both Africa and Latin America, with the most striking changes taking place in Latin America. The bulk of the di...

Modeled sensitivity of Lake Michigan productivity and zooplankton to changing nutrient concentrations and quagga mussels

Science.gov (United States)

Pilcher, Darren J.; McKinley, Galen A.; Kralj, James; Bootsma, Harvey A.; Reavie, Euan D.

2017-08-01

The recent decline in Lake Michigan productivity is often attributed to filter feeding by invasive quagga mussels, but some studies also implicate reductions in lakewide nutrient concentrations. We use a 3-D coupled hydrodynamic-biogeochemical model to evaluate the effect of changing nutrient concentrations and quagga mussel filtering on phytoplankton production and phytoplankton and zooplankton biomass. Sensitivity experiments are used to assess the net effect of each change separately and in unison. Quagga mussels are found to have the greatest impact during periods of isothermal mixing, while nutrients have the greatest impact during thermal stratification. Quagga mussels also act to enhance spatial heterogeneity, particularly between nearshore-offshore regions. This effect produces a reversal in the gradient of nearshore-offshore productivity: from relatively greater nearshore productivity in the prequagga lake to relatively lesser nearshore productivity after quaggas. The combined impact of both processes drives substantial reductions in phytoplankton and zooplankton biomass, as well as significant modifications to the seasonality of surface water pCO2, particularly in nearshore regions where mussel grazing continues year-round. These results support growing concern that considerable losses of phytoplankton and zooplankton will yield concurrent losses at higher trophic levels. Comparisons to observed productivity suggest that both quagga mussel filtration and lower lakewide total phosphorus are necessary to accurately simulate recent changes in primary productivity in Lake Michigan.

LCA as a decision support tool in policy making: the case study of Danish spring barley production in a changed climate

DEFF Research Database (Denmark)

Niero, Monia; Ingvordsen, Cathrine Heinz; Hauschild, Michael Zwicky

2015-01-01

Life Cycle Assessment (LCA) can support policy makers in the choice of the most effective measures to adapt to climate change in crop production. A case study involving spring barley cultivation in Denmark under changed climate conditions has been performed using primary data from future climate...

Carrot Loss during Primary Production : Field Waste and Pack House Waste.

OpenAIRE

Bond, Rebekka

2016-01-01

Background: it has been suggested that roughly one-third of all food produced for human consumption is lost or wasted globally. The reduction of loss and waste is seen as an important societal issue with considerable ethical, ecological and economic implications. Fruit and vegetables have the highest wastage rates of any food products; (45 %). And a big part of this waste occurs during production, but empirical data on loss during primary production is limited. Carrots are an important hortic...

Nitrogenous nutrients and primary production in a tropical oceanic environment

Digital Repository Service at National Institute of Oceanography (India)

Wafar, M.V.M.; Wafar, S.; Devassy, V.P.

Measurements of the concentrations of nitrogenous nutrients and primary production were made at 10 stations along 8 degrees N and 10 degrees N in the tropical oceanic Lakshadweep waters Inorganic nitrogen (NO3, NO2 and NH4) accounted for less than...

Net primary productivity and its partitioning in response to precipitation gradient in an alpine meadow.

Science.gov (United States)

Zhang, Fangyue; Quan, Quan; Song, Bing; Sun, Jian; Chen, Youjun; Zhou, Qingping; Niu, Shuli

2017-11-09

The dynamics of net primary productivity (NPP) and its partitioning to the aboveground versus belowground are of fundamental importance to understand carbon cycling and its feedback to climate change. However, the responses of NPP and its partitioning to precipitation gradient are poorly understood. We conducted a manipulative field experiment with six precipitation treatments (1/12 P, 1/4 P, 1/2 P, 3/4 P, P, and 5/4 P, P is annual precipitation) in an alpine meadow to examine aboveground and belowground NPP (ANPP and BNPP) in response to precipitation gradient in 2015 and 2016. We found that changes in precipitation had no significant impact on ANPP or belowground biomass in 2015. Compared with control, only the extremely drought treatment (1/12 P) significantly reduced ANPP by 37.68% and increased BNPP at the depth of 20-40 cm by 80.59% in 2016. Across the gradient, ANPP showed a nonlinear response to precipitation amount in 2016. Neither BNPP nor NPP had significant relationship with precipitation changes. The variance in ANPP were mostly due to forbs production, which was ultimately caused by altering soil water content and soil inorganic nitrogen concentration. The nonlinear precipitation-ANPP relationship indicates that future precipitation changes especially extreme drought will dramatically decrease ANPP and push this ecosystem beyond threshold.

Scaling Gross Primary Production (GPP) over boreal and deciduous forest landscapes in support of MODIS GPP product validation.

Science.gov (United States)

David P. Turner; William D. Ritts; Warren B. Cohen; Stith T. Gower; Maosheng Zhao; Steve W. Running; Steven C. Wofsy; Shawn Urbanski; Allison L. Dunn; J.W. Munger

2003-01-01

The Moderate Resolution Imaging Radiometer (MODIS) is the primary instrument in the NASA Earth Observing System for monitoring the seasonality of global terrestrial vegetation. Estimates of 8-day mean daily gross primary production (GPP) at the 1 km spatial resolution are now operationally produced by the MODIS Land Science Team for the global terrestrial surface using...

Synthesis of integrated primary production in the Arctic Ocean: II. In situ and remotely sensed estimates

Science.gov (United States)

Hill, Victoria J.; Matrai, Patricia A.; Olson, Elise; Suttles, S.; Steele, Mike; Codispoti, L. A.; Zimmerman, Richard C.

2013-03-01

Recent warming of surface waters, accompanied by reduced ice thickness and extent may have significant consequences for climate-driven changes of primary production (PP) in the Arctic Ocean (AO). However, it has been difficult to obtain a robust benchmark estimate of pan-Arctic PP necessary for evaluating change. This paper provides an estimate of pan-Arctic PP prior to significant warming from a synthetic analysis of the ARCSS-PP database of in situ measurements collected from 1954 to 2007 and estimates derived from satellite-based observations from 1998 to 2007. Vertical profiles of in situ chlorophyll a (Chl a) and PP revealed persistent subsurface peaks in biomass and PP throughout the AO during most of the summer period. This was contradictory with the commonly assumed exponential decrease in PP with depth on which prior satellite-derived estimates were based. As remotely sensed Chl a was not a good predictor of integrated water column Chl a, accurate satellite-based modeling of vertically integrated primary production (IPPsat), requires knowledge of the subsurface distribution of phytoplankton, coincident with the remotely sensed ocean color measurements. We developed an alternative approach to modeling PP from satellite observations by incorporating climatological information on the depths of the euphotic zone and the mixed layer that control the distribution of phytoplankton that significantly improved the fidelity of satellite derived PP to in situ observations. The annual IPP of the Arctic Ocean combining both in situ and satellite based estimates was calculated here to be a minimum of 466 ± 94 Tg C yr-1 and a maximum of 993 ± 94 Tg C yr-1, when corrected for subsurface production. Inflow shelf seas account for 75% of annual IPP, while the central basin and Beaufort northern sea were the regions with the lowest annual integrated productivity, due to persistently stratified, oligotrophic and ice-covered conditions. Although the expansion of summertime

Primary Productivity, NASA Aqua MODIS and GOES Imager, 0.1 degrees, Global, EXPERIMENTAL

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Primary Productivity is calculated from NASA Aqua MODIS Chl a and NOAA GOES Imager SST data. THIS IS AN EXPERIMENTAL PRODUCT: intended strictly for scientific...

77 FR 71691 - Type Certification Procedures for Changed Products

Science.gov (United States)

2012-12-04

...-8994; Amdt. No. 21-96] RIN 2120-AK19 Type Certification Procedures for Changed Products AGENCY: Federal... regulations for the certification of changes to type-certificated products. That amendment was to enhance... (certification) of the entire changed product. Therefore, Sec. 21.101 is amended to replace ``changed product...

Montana's forest products industry and timber harvest, 2004

Science.gov (United States)

Timothy P. Spoelma; Todd A. Morgan; Thale Dillon; Alfred L. Chase; Charles E. Keegan; Larry T. DeBlander

2008-01-01

This report traces the flow of Montana's 2004 timber harvest through the primary wood-using industries; provides a description of the structure, capacity, and condition of Montana's primary forest products industry; and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as changes in harvest, production...

Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?

Science.gov (United States)

Reyer, Christopher P. O.; Bathgate, Stephen; Blennow, Kristina; Borges, Jose G.; Bugmann, Harald; Delzon, Sylvain; Faias, Sonia P.; Garcia-Gonzalo, Jordi; Gardiner, Barry; Gonzalez-Olabarria, Jose Ramon; Gracia, Carlos; Guerra Hernández, Juan; Kellomäki, Seppo; Kramer, Koen; Lexer, Manfred J.; Lindner, Marcus; van der Maaten, Ernst; Maroschek, Michael; Muys, Bart; Nicoll, Bruce; Palahi, Marc; Palma, João HN; Paulo, Joana A.; Peltola, Heli; Pukkala, Timo; Rammer, Werner; Ray, Duncan; Sabaté, Santiago; Schelhaas, Mart-Jan; Seidl, Rupert; Temperli, Christian; Tomé, Margarida; Yousefpour, Rasoul; Zimmermann, Niklaus E.; Hanewinkel, Marc

2017-03-01

Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures.

Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?

Science.gov (United States)

Reyer, Christopher P O; Bathgate, Stephen; Blennow, Kristina; Borges, Jose G; Bugmann, Harald; Delzon, Sylvain; Faias, Sonia P; Garcia-Gonzalo, Jordi; Gardiner, Barry; Gonzalez-Olabarria, Jose Ramon; Gracia, Carlos; Hernández, Juan Guerra; Kellomäki, Seppo; Kramer, Koen; Lexer, Manfred J; Lindner, Marcus; van der Maaten, Ernst; Maroschek, Michael; Muys, Bart; Nicoll, Bruce; Palahi, Marc; Palma, João HN; Paulo, Joana A; Peltola, Heli; Pukkala, Timo; Rammer, Werner; Ray, Duncan; Sabaté, Santiago; Schelhaas, Mart-Jan; Seidl, Rupert; Temperli, Christian; Tomé, Margarida; Yousefpour, Rasoul; Zimmermann, Niklaus E; Hanewinkel, Marc

2017-01-01

Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures. PMID:28855959

Primary productivity in the Karwar Bay, Karnataka, west coast of India

Digital Repository Service at National Institute of Oceanography (India)

Naik, U.G.; Naik, R.K.; Nayak, V.N.

The measurement of primary production is of great importance because of its significance to the problems of aquatic ecology and fishery management. The interaction of light intensity, temperature and nutrient levels determines the photosynthetic...

Remote sensing of oceanic primary production: Computations using a spectral model

Digital Repository Service at National Institute of Oceanography (India)

Sathyendranath, S.; Platt, T.; Caverhill, C.M.; Warnock, R.E.; Lewis, M.R.

A spectral model of underwater irradiance is coupled with a spectral version of the photosynthesis-light relationship to compute oceanic primary production. The results are shown to be significantly different from those obtained using...

Climate Change and Maize Production: Empirical Evidence from ...

African Journals Online (AJOL)

Michael Madukwe

humanity with food and fiber, while climate is the primary determinant of agricultural ... Extension systems can help farmers deal with climate change by providing them information on causes and effects of climate change as well as adaptive ...

Age-related changes in the functional neuroanatomy of overt speech production.

Science.gov (United States)

Sörös, Peter; Bose, Arpita; Sokoloff, Lisa Guttman; Graham, Simon J; Stuss, Donald T

2011-08-01

Alterations of existing neural networks during healthy aging, resulting in behavioral deficits and changes in brain activity, have been described for cognitive, motor, and sensory functions. To investigate age-related changes in the neural circuitry underlying overt non-lexical speech production, functional MRI was performed in 14 healthy younger (21-32 years) and 14 healthy older individuals (62-84 years). The experimental task involved the acoustically cued overt production of the vowel /a/ and the polysyllabic utterance /pataka/. In younger and older individuals, overt speech production was associated with the activation of a widespread articulo-phonological network, including the primary motor cortex, the supplementary motor area, the cingulate motor areas, and the posterior superior temporal cortex, similar in the /a/ and /pataka/ condition. An analysis of variance with the factors age and condition revealed a significant main effect of age. Irrespective of the experimental condition, significantly greater activation was found in the bilateral posterior superior temporal cortex, the posterior temporal plane, and the transverse temporal gyri in younger compared to older individuals. Significantly greater activation was found in the bilateral middle temporal gyri, medial frontal gyri, middle frontal gyri, and inferior frontal gyri in older vs. younger individuals. The analysis of variance did not reveal a significant main effect of condition and no significant interaction of age and condition. These results suggest a complex reorganization of neural networks dedicated to the production of speech during healthy aging. Copyright © 2009 Elsevier Inc. All rights reserved.

Corrosion product behaviour in the primary circuit of the KNK nuclear reactor facility

International Nuclear Information System (INIS)

Stamm, H.H.; Stade, K.Ch.

1976-01-01

During nuclear operation of the KNK facility from 1972 until September 1974 the composition and behaviour of radionuclides occuring in the primary circuit were investigated. Besides traces of 140 Ba/ 140 La, no fission product activity was detectable in the KNK primary circuit. The fuel element purification from sodium deposits (prior to transport to the reprocessing plant) did not yield any indication of a fuel element failure during KNK-I operation. The activity inventory of the primary loop was exclusively made up of activated corrosion products and 22 Na. The main activity was due to 65 Zn, followed by 54 Mn, 22 Na, sup(110m)Ag, 182 Ta, 60 Co and 124 Sb. It was found that the sorption of 65 Zn and 54 Mn on crucibles made from nickel was condiserably higher than on vessels made from other materials. This observation was confirmed both in tests with material samples from the primary circuit and for disks of gate valves of the primary circuit. sup(110m)Ag did hardly exhibit any sorption effects and had been dissolved largely homogeneously in the hot primary coolant. In the first primary cold trap which was removed from the circuit after some 20,000 hours of operation, only 65 Zn and 54 Mn were detected in addition to traces of 60 Co and 182 Ta. (author)

Assessing changes in biomass, productivity, and C and N stores following Juniperus virginiana forest expansion into tallgrass prairie

Energy Technology Data Exchange (ETDEWEB)

Norris, M. D.; Blair, J. M.; Johnson, L. C. [Kansas State Univ., Manhattan, KS (United States); McKane, R. B. [Environmental Protection Agency, Western Ecology Division, Corvallis, OR (United States)

2001-11-01

The objective of this study was to assess changes in plant productivity and above-ground plant biomass associated with red cedar forest expansion into areas formerly dominated by tallgrass prairie. Regionally appropriate allometric biomass regression equations were developed for the nondestructive estimation of red cedar biomass in eastern Kansas, followed by quantification of the carbon and nitrogen content of selected biomass components. The equations were applied, along with measurements of leaf litter production, to selected local stands of mature closed-canopy red cedars to estimate above-ground biomass, standing stocks of carbon and nitrogen and annual above-ground net primary productivity. Above-ground plant biomass for these red cedar-dominated sites ranged from 114,100 kg/ha for the youngest stand to 210,700 kg/ha for the oldest. Annual above-ground net primary productivity (ANPP) ranged from 7,250 to 10,440 kg/ha/yr for the oldest and younger red cedar stands respectively. The ANPP in comparable tallgrass prairie sites in this region averages 3,690 k/ha/yr, indicating a large increase in carbon uptake and above-ground storage as a result of the change from prairie to red cedar forests. Comparing these results with similar published data from other sites led to the conclusion that the widespread change from tallgrass to red cedars across the woodland-prairie ecotone has important consequences for regional carbon storage.37 refs., 3 tabs., 3 figs.

Frontal dynamics boost primary production in the summer stratified Mediterranean sea

Science.gov (United States)

Olita, Antonio; Capet, Arthur; Claret, Mariona; Mahadevan, Amala; Poulain, Pierre Marie; Ribotti, Alberto; Ruiz, Simón; Tintoré, Joaquín; Tovar-Sánchez, Antonio; Pascual, Ananda

2017-06-01

Bio-physical glider measurements from a unique process-oriented experiment in the Eastern Alboran Sea (AlborEx) allowed us to observe the distribution of the deep chlorophyll maximum (DCM) across an intense density front, with a resolution (˜ 400 m) suitable for investigating sub-mesoscale dynamics. This front, at the interface between Atlantic and Mediterranean waters, had a sharp density gradient (Δ ρ ˜ 1 kg/m3 in ˜ 10 km) and showed imprints of (sub-)mesoscale phenomena on tracer distributions. Specifically, the chlorophyll-a concentration within the DCM showed a disrupted pattern along isopycnal surfaces, with patches bearing a relationship to the stratification (buoyancy frequency) at depths between 30 and 60 m. In order to estimate the primary production (PP) rate within the chlorophyll patches observed at the sub-surface, we applied the Morel and Andrè (J Geophys Res 96:685-698 1991) bio-optical model using the photosynthetic active radiation (PAR) from Argo profiles collected simultaneously with glider data. The highest production was located concurrently with domed isopycnals on the fresh side of the front, suggestive that (sub-)mesoscale upwelling is carrying phytoplankton patches from less to more illuminated levels, with a contemporaneous delivering of nutrients. Integrated estimations of PP (1.3 g C m-2d-1) along the glider path are two to four times larger than the estimations obtained from satellite-based algorithms, i.e., derived from the 8-day composite fields extracted over the glider trip path. Despite the differences in spatial and temporal sampling between instruments, the differences in PP estimations are mainly due to the inability of the satellite to measure DCM patches responsible for the high production. The deepest (depth > 60 m) chlorophyll patches are almost unproductive and probably transported passively (subducted) from upper productive layers. Finally, the relationship between primary production and oxygen is also investigated

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.

Automation for Primary Processing of Hardwoods

Science.gov (United States)

Daniel L. Schmoldt

1992-01-01

Hardwood sawmills critically need to incorporate automation and computer technology into their operations. Social constraints, forest biology constraints, forest product market changes, and financial necessity are forcing primary processors to boost their productivity and efficiency to higher levels. The locations, extent, and types of defects found in logs and on...

Diagnosis of compliance of health care product processing in Primary Health Care

Directory of Open Access Journals (Sweden)

Camila Eugenia Roseira

Full Text Available ABSTRACT Objective: identify the compliance of health care product processing in Primary Health Care and assess possible differences in the compliance among the services characterized as Primary Health Care Service and Family Health Service. Method: quantitative, observational, descriptive and inferential study with the application of structure, process and outcome indicators of the health care product processing at ten services in an interior city of the State of São Paulo - Brazil. Results: for all indicators, the compliance indices were inferior to the ideal levels. No statistically significant difference was found in the indicators between the two types of services investigated. The health care product cleaning indicators obtained the lowest compliance index, while the indicator technical-operational resources for the preparation, conditioning, disinfection/sterilization, storage and distribution of health care products obtained the best index. Conclusion: the diagnosis of compliance of health care product processing at the services assessed indicates that the quality of the process is jeopardized, as no results close to ideal levels were obtained at any service. In addition, no statistically significant difference in these indicators was found between the two types of services studied.

76 FR 77271 - Competitive Product Postal Price Changes

Science.gov (United States)

2011-12-12

... POSTAL REGULATORY COMMISSION [Docket No. CP2012-2; Order No. 997] Competitive Product Postal Price... recently-filed Postal Service request for a change in competitive products prices. The changes will take... and justification for the changes, the effective date, and a schedule of the changed rates. The price...

Ocean primary production and available light: Further algorithms for remote sensing

Digital Repository Service at National Institute of Oceanography (India)

Platt, T.; Sathyendranath, S.; Caverhill, C.M.; Lewis, M.R.

(1986, Deep-Sea Research, 33, 149-163) Further empirical evidence is presented to show the stability of the relationship between surface light and biomass-normalized primary production of the ocean water column A theoretical explanation is given...

Recruitment and condition of juvenile sandeel on the Faroe shelf in relation to primary production

DEFF Research Database (Denmark)

Eliasen, Kirstin; Reinert, Jákup; Gaard, Eilif

The food of early-life sandeel is dominated by zooplankton, which again depends on primary production. On the Faroe Shelf, measurements of accumulated new primary production and chlorophyll a during spring and summer have been carried out since 1990 and 1997, respectively. Large inter...... availability. We compare the time series from the sandeel 0-group surveys with data on phytoplankton production and biomass. The results confirm that survival and condition of the early-life stages of sandeel on the Faroe Shelf is dependent on the magnitude of the primary production. Although the sandeel......-annual variations in the onset of the spring bloom and its intensity have been observed. Since 1974 juvenile sandeels have been sampled annually on the Faroe shelf. These results also show large variations – both in number and in average length. Here, we investigate the variations in recruitment in relation to food...

Organic carbon fluxes in the Atlantic and the Southern Ocean: relationship to primary production compiled from satellite radiometer data

Science.gov (United States)

Fischer, G.; Ratmeyer, V.; Wefer, G.

Fluxes of organic carbon normalised to a depth of 1000 m from 18 sites in the Atlantic and the Southern Ocean are presented, comprising nine biogeochemical provinces as defined by Longhurst et al. (1995. Journal of Plankton Research 17, 1245-1271). For comparison with primary production, we used a recent compilation of primary production values derived from CZCS data (Antoine et al., 1996. Global Biogeochemical Cycles 10, 57-69). In most cases, the seasonal patterns stood reasonably well in accordance with the carbon fluxes. Particularly, organic carbon flux records from two coastal sites off northwest and southwest Africa displayed a more distinct correlation to the primary production in sectors (1×1°) which are situated closer to the coastal environments. This was primarily caused by large upwelling filaments streaming far offshore, resulting in a cross-shelf carbon transport. With respect to primary production, organic carbon export to a water depth of 1000 m, and the fraction of primary production exported to a depth of 1000 m (export fraction=EF 1000), we were able to distinguish between: (1) the coastal environments with highest values (EF 1000=1.75-2.0%), (2) the eastern equatorial upwelling area with moderately high values (EF 1000=0.8-1.1%), (3) and the subtropical oligotrophic gyres that yielded lowest values (EF 1000=0.6%). Carbon export in the Southern Ocean was low to moderate, and the EF 1000 value seems to be quite low in general. Annual organic carbon fluxes were proportional to primary production, and the export fraction EF 1000 increased with primary production up to 350 gC m -2 yr-1. Latitudinal variations in primary production were reflected in the carbon flux pattern. A high temporal variability of primary production rates and a pronounced seasonality of carbon export were observed in the polar environments, in particular in coastal domains, although primary production (according to Antoine et al., 1996. Global Biogeochemical Cycles 10, 57

Phytoplankton pigments and primary production around the oil fields off Maharashtra

Digital Repository Service at National Institute of Oceanography (India)

JiyalalRam, M.J.; Ramaiah, Neelam; Mehta, P.; Krishnakumari, L.; Nair, V.R.

Studies on phytoplankton pigments, primary productivity and particulate organic carbon were made at 21 locations off Bombay (Maharashtra, India) and adjacent waters during the 48th cruise of @iORV Sagar Kanya@@ in December 1988 to January 1989...

77 FR 64567 - Product List Change

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2012-10-22

... Delivery service from the competitive product list due to low customer demand.\\2\\ It states that there are... POSTAL REGULATORY COMMISSION [Docket No. MC2013-3; Order No. 1503] Product List Change AGENCY... product list. This notice provides public notice of the Postal Service's filing, invites public comment...

Benthic-planktonic coupling, regime shifts, and whole-lake primary production in shallow lakes.

Science.gov (United States)

Genkai-Kato, Motomi; Vadeboncoeur, Yvonne; Liboriussen, Lone; Jeppesen, Erik

2012-03-01

Alternative stable states in shallow lakes are typically characterized by submerged macrophyte (clear-water state) or phytoplankton (turbid state) dominance. However, a clear-water state may occur in eutrophic lakes even when macrophytes are absent. To test whether sediment algae could cause a regime shift in the absence of macrophytes, we developed a model of benthic (periphyton) and planktonic (phytoplankton) primary production using parameters derived from a shallow macrophyte-free lake that shifted from a turbid to a clear-water state following fish removal (biomanipulation). The model includes a negative feedback effect of periphyton on phosphorus (P) release from sediments. This in turn induces a positive feedback between phytoplankton production and P release. Scenarios incorporating a gradient of external P loading rates revealed that (1) periphyton and phytoplankton both contributed substantially to whole-lake production over a broad range of external P loading in a clear-water state; (2) during the clear-water state, the loss of benthic production was gradually replaced by phytoplankton production, leaving whole-lake production largely unchanged; (3) the responses of lakes to biomanipulation and increased external P loading were both dependent on lake morphometry; and (4) the capacity of periphyton to buffer the effects of increased external P loading and maintain a clear-water state was highly sensitive to relationships between light availability at the sediment surface and the of P release. Our model suggests a mechanism for the persistence of alternative states in shallow macrophyte-free lakes and demonstrates that regime shifts may trigger profound changes in ecosystem structure and function.

Primary souring: A novel bacteria-free method for sour beer production.

Science.gov (United States)

Osburn, Kara; Amaral, Justin; Metcalf, Sara R; Nickens, David M; Rogers, Cody M; Sausen, Christopher; Caputo, Robert; Miller, Justin; Li, Hongde; Tennessen, Jason M; Bochman, Matthew L

2018-04-01

In the beverage fermentation industry, especially at the craft or micro level, there is a movement to incorporate as many local ingredients as possible to both capture terroir and stimulate local economies. In the case of craft beer, this has traditionally only encompassed locally sourced barley, hops, and other agricultural adjuncts. The identification and use of novel yeasts in brewing lags behind. We sought to bridge this gap by bio-prospecting for wild yeasts, with a focus on the American Midwest. We isolated 284 different strains from 54 species of yeast and have begun to determine their fermentation characteristics. During this work, we found several isolates of five species that produce lactic acid and ethanol during wort fermentation: Hanseniaspora vineae, Lachancea fermentati, Lachancea thermotolerans, Schizosaccharomyces japonicus, and Wickerhamomyces anomalus. Tested representatives of these species yielded excellent attenuation, lactic acid production, and sensory characteristics, positioning them as viable alternatives to lactic acid bacteria (LAB) for the production of sour beers. Indeed, we suggest a new LAB-free paradigm for sour beer production that we term "primary souring" because the lactic acid production and resultant pH decrease occurs during primary fermentation, as opposed to kettle souring or souring via mixed culture fermentation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Matching Social and Biophysical Scales in Extensive Livestock Production as a Basis for Adaptation to Global Change

Science.gov (United States)

Sayre, N. F.; Bestelmeyer, B.

2015-12-01

Global livestock production is heterogeneous, and its benefits and costs vary widely across global contexts. Extensive grazing lands (or rangelands) constitute the vast majority of the land dedicated to livestock production globally, but they are relatively minor contributors to livestock-related environmental impacts. Indeed, the greatest potential for environmental damage in these lands lies in their potential for conversion to other uses, including agriculture, mining, energy production and urban development. Managing such conversion requires improving the sustainability of livestock production in the face of fragmentation, ecological and economic marginality and climate change. We present research from Mongolia and the United States demonstrating methods of improving outcomes on rangelands by improving the fit between the scales of social and biophysical processes. Especially in arid and semi-arid settings, rangelands exhibit highly variable productivity over space and time and non-linear or threshold dynamics in vegetation; climate change is projected to exacerbate these challenges and, in some cases, diminish overall productivity. Policy and governance frameworks that enable landscape-scale management and administration enable range livestock producers to adapt to these conditions. Similarly, livestock breeds that have evolved to withstand climate and vegetation change improve producers' prospects in the face of increasing variability and declining productivity. A focus on the relationships among primary production, animal production, spatial connectivity, and scale must underpin adaptation strategies in rangelands.

Parameterization of surface irradiance and primary production in Århus Bay, SW Kattegat, Baltic Sea

DEFF Research Database (Denmark)

Lund-Hansen, Lars Chresten; Sørensen, Helene Munk

2009-01-01

. The study is based on a one year long time-series of PAR, CTD-casts (n = 45), and primary production measurements (n = 24) from Århus Bay (56°09′ N; 10°20′ E), south west Kattegat. Results showed a high and positive correlation between observed and calculated primary production in the bay, as based...

Long-term space changes after premature loss of a primary maxillary first molar

OpenAIRE

Lin, Yng-Tzer J.; Lin, Yai-Tin

2016-01-01

Background/purpose: The consequence of premature loss of primary teeth resulting in the need for space maintainers has been controversial for many years. There is no longitudinal long-term report in literature regarding the premature loss of a primary maxillary first molar. The aim of this study was to continue observing the long-term space changes of 19 cases following premature loss of a primary maxillary first molar during the transition from primary to permanent dentition. Materials an...

Seasonal primary production in different sectors of the EEZ of India

Digital Repository Service at National Institute of Oceanography (India)

Sarupria, J.S.; Bhargava, R.M.S.

The seasonal and regional variations in the primary production, based on the data collected at 562 stations over the period from 1962 to 1988, are presented. The entire Indian Exclusive Economic Zone (EEZ), measuring 2.01 million km super(2...

UV radiation and natural fluorescence linked primary production in Antarctic waters

Digital Repository Service at National Institute of Oceanography (India)

LokaBharathi, P.A.; KrishnaKumari, L.; Bhattathiri, P.M.A.; Chandramohan, D.

Primary productivity and chlorophyll values have been measured using an underwater profiling radiometer for the first time in the waters around Indian Antarctic Station (70°46'S & 11°44'E) in the summer of 1994. The profiles include natural...

Dominant role of plant physiology in trend and variability of gross primary productivity in North America

Science.gov (United States)

Zhou, Sha; Zhang, Yao; Ciais, Philippe; Xiao, Xiangming; Luo, Yiqi; Caylor, Kelly K.; Huang, Yuefei; Wang, Guangqian

2017-02-01

Annual gross primary productivity (GPP) varies considerably due to climate-induced changes in plant phenology and physiology. However, the relative importance of plant phenology and physiology on annual GPP variation is not clear. In this study, a Statistical Model of Integrated Phenology and Physiology (SMIPP) was used to evaluate the relative contributions of maximum daily GPP (GPPmax) and the start and end of growing season (GSstart and GSend) to annual GPP variability, using a regional GPP product in North America during 2000-2014 and GPP data from 24 AmeriFlux sites. Climatic sensitivity of the three indicators was assessed to investigate the climate impacts on plant phenology and physiology. The SMIPP can explain 98% of inter-annual variability of GPP over mid- and high latitudes in North America. The long-term trend and inter-annual variability of GPP are dominated by GPPmax both at the ecosystem and regional scales. During warmer spring and autumn, GSstart is advanced and GSend delayed, respectively. GPPmax responds positively to summer temperature over high latitudes (40-80°N), but negatively in mid-latitudes (25-40°N). This study demonstrates that plant physiology, rather than phenology, plays a dominant role in annual GPP variability, indicating more attention should be paid to physiological change under futher climate change.

Changes in Student Populations and Average Test Scores of Dutch Primary Schools

Science.gov (United States)

Luyten, Hans; de Wolf, Inge

2011-01-01

This article focuses on the relation between student population characteristics and average test scores per school in the final grade of primary education from a dynamic perspective. Aggregated data of over 5,000 Dutch primary schools covering a 6-year period were used to study the relation between changes in school populations and shifts in mean…

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...

Accounting for graduate medical education production of primary care physicians and general surgeons: timing of measurement matters.

Science.gov (United States)

Petterson, Stephen; Burke, Matthew; Phillips, Robert; Teevan, Bridget

2011-05-01

Legislation proposed in 2009 to expand GME set institutional primary care and general surgery production eligibility thresholds at 25% at entry into training. The authors measured institutions' production of primary care physicians and general surgeons on completion of first residency versus two to four years after graduation to inform debate and explore residency expansion and physician workforce implications. Production of primary care physicians and general surgeons was assessed by retrospective analysis of the 2009 American Medical Association Masterfile, which includes physicians' training institution, residency specialty, and year of completion for up to six training experiences. The authors measured production rates for each institution based on physicians completing their first residency during 2005-2007 in family or internal medicine, pediatrics, or general surgery. They then reassessed rates to account for those who completed additional training. They compared these rates with proposed expansion eligibility thresholds and current workforce needs. Of 116,004 physicians completing their first residency, 54,245 (46.8%) were in primary care and general surgery. Of 683 training institutions, 586 met the 25% threshold for expansion eligibility. At two to four years out, only 29,963 physicians (25.8%) remained in primary care or general surgery, and 135 institutions lost eligibility. A 35% threshold eliminated 314 institutions collectively training 93,774 residents (80.8%). Residency expansion thresholds that do not account for production at least two to four years after completion of first residency overestimate eligibility. The overall primary care production rate from GME will not sustain the current physician workforce composition. Copyright © by the Association of American medical Colleges.

78 FR 16779 - Type Certification Procedures for Changed Products

Science.gov (United States)

2013-03-19

...-8994; Amdt. No. 21-96] RIN 2120-AK19 Type Certification Procedures for Changed Products AGENCY: Federal... requirements for the certification of changes to type-certificated products. The revision required the... entitled, ``Type Certification Procedures for Changed Products'' (December 4, 2012, 77 FR 71691). The 2000...

Primary oxidation and reduction products in x-irradiated aspartic acid

International Nuclear Information System (INIS)

Adams, S.M.; Budzinski, E.E.; Box, H.C.

1976-01-01

The primary reduction products identified by ESR--ENDOR spectroscopy in single crystals of DL-aspartic acid hydrochloride irradiated at 4.2degreeK are anions formed by addition of an electron to the carbonyl oxygen atoms of the carboxylic acid groups. The main consequence of the oxidation process is to produce a hole centered mainly on atomic chlorine

Productivity Change, Technical Progress, and Relative Efficiency Change in the Public Accounting Industry

OpenAIRE

Rajiv D. Banker; Hsihui Chang; Ram Natarajan

2005-01-01

We present evidence on components of productivity change in the public accounting industry toward the end of the 20th century. Using revenue and human resource data from 64 of the 100 largest public accounting firms in the United States for the 1995--1999 period, we analyze productivity change, technical progress, and relative efficiency change over time. The average public accounting firm experienced a productivity growth of 9.5% between 1995 and 1999. We find support for the hypothesis that...

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.

Assessing ozone and nitrogen impact on net primary productivity with a Generalised non-Linear Model

International Nuclear Information System (INIS)

De Marco, Alessandra; Screpanti, Augusto; Attorre, Fabio; Proietti, Chiara; Vitale, Marcello

2013-01-01

Some studies suggest that in Europe the majority of forest growth increment can be accounted for N deposition and very little by elevated CO 2 . High ozone (O 3 ) concentrations cause reductions in carbon fixation in native plants by offsetting the effects of elevated CO 2 or N deposition. The cause-effect relationships between primary productivity (NPP) of Quercus cerris, Q. ilex and Fagus sylvatica plant species and climate and pollutants (O 3 and N deposition) in Italy have been investigated by application of Generalised Linear/non-Linear regression model (GLZ model). The GLZ model highlighted: i) cumulative O 3 concentration-based indicator (AOT40F) did not significantly affect NPP; ii) a differential action of oxidised and reduced nitrogen depositions to NPP was linked to the geographical location; iii) the species-specific variation of NPP caused by combination of pollutants and climatic variables could be a potentially important drive-factor for the plant species' shift as response to the future climate change. - Highlights: ► GLZ Models emphasized the role of combination of variables affecting NPP. ► A differential action of ox-N and red-N deposition to NPP was observed for plants. ► Different responses to climate and pollutants could affect the plant species' shift. - Ozone and nitrogen depositions have non-linear effects on primary productivity of tree species differently distributed in Italy.

Investigating smoke's influence on primary production throughout the Amazon

Science.gov (United States)

Flanner, M. G.; Mahowald, N. M.; Zender, C. S.; Randerson, J. T.; Tosca, M. G.

2007-12-01

Smoke from annual burning in the Amazon causes large reduction in surface insolation and increases the diffuse fraction of photosynthetically-active radiation (PAR). These effects have competing influence on gross primary production (GPP). Recent studies indicate that the sign of net influence depends on aerosol optical depth, but the magnitude of smoke's effect on continental-scale carbon cycling is very poorly constrained and may constitute an important term of fire's net impact on carbon storage. To investigate widespread effects of Amazon smoke on surface radiation properties, we apply a version of the NCAR Community Atmosphere Model with prognostic aerosol transport, driven with re-analysis winds. Carbon aerosol emissions are derived from the Global Fire Emissions Database (GFED). We use AERONET observations to identify model biases in aerosol optical depth, single-scatter albedo, and surface radiative forcing, and prescribe new aerosol optical properties based on field observations to improve model agreement with AERONET data. Finally, we quantify a potential range of smoke-induced change in large-scale GPP based on: 1) ground measurements of GPP in the Amazon as a function of aerosol optical depth and diffuse fraction of PAR, and 2) empirical functions of ecosystem-scale photosynthesis rates currently employed in models such as the Community Land Model (CLM).

Changes in productivity of grassland with ageing

NARCIS (Netherlands)

Hoogerkamp, M.

1984-01-01

The productivity of grassland may change greatly with ageing. Frequently, a productive ley period, occurring in the first time after (re)seeding, is followed by a period in which productivity decreases. Under conditions favourable to grassland this may be temporary. A production level

Examining organizational change in primary care practices: experiences from using ethnographic methods.

Science.gov (United States)

Russell, Grant; Advocat, Jenny; Geneau, Robert; Farrell, Barbara; Thille, Patricia; Ward, Natalie; Evans, Samantha

2012-08-01

Qualitative methods are an important part of the primary care researcher's toolkit providing a nuanced view of the complexity in primary care reform and delivery. Ethnographic research is a comprehensive approach to qualitative data collection, including observation, in-depth interviews and document analysis. Few studies have been published outlining methodological issues related to ethnography in this setting. This paper examines some of the challenges of conducting an ethnographic study in primary care setting in Canada, where there recently have been major reforms to traditional methods of organizing primary care services. This paper is based on an ethnographic study set in primary care practices in Ontario, Canada, designed to investigate changes to organizational and clinical routines in practices undergoing transition to new, interdisciplinary Family Health Teams (FHTs). The study was set in six new FHTs in Ontario. This paper is a reflexive examination of some of the challenges encountered while conducting an ethnographic study in a primary care setting. Our experiences in this study highlight some potential benefits of and difficulties in conducting an ethnographic study in family practice. Our study design gave us an opportunity to highlight the changes in routines within an organization in transition. A study with a clinical perspective requires training, support, a mixture of backgrounds and perspectives and ongoing communication. Despite some of the difficulties, the richness of this method has allowed the exploration of a number of additional research questions that emerged during data analysis.

Fission and corrosion products behavior in primary circuits of LMFBR's

International Nuclear Information System (INIS)

Feuerstein, H.; Thorley, A.W.

1987-08-01

Most of the 20 presented papers report items belonging to more than one session. The equipment results of primary circuits of LMFBR's relative to corrosion and fission products, release and chemistry of fuel, measurement techniques and analytical procedures of sodium sampling, difficulties with radionuclides and particles, reactor experiences with EBR-II, FFTF, BR10, BOR60, BN350, BN600, JOYO, and KNK-II, DFR, PFR, RAPSODIE, PHENIX, and SUPERPHENIX, and at least the verification of codes for calculation models of radioactive products accumulation and distribution are described. All 20 papers presented at the meeting are separately indexed in the database. (DG)

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%.

The production of direct object clitics in pre-school- and primary school-aged children with specific language impairments.

Science.gov (United States)

Guasti, Maria Teresa; Palma, Silvia; Genovese, Elisabetta; Stagi, Paolo; Saladini, Gabriella; Arosio, Fabrizio

2016-01-01

Third-person direct object (DO) clitic pronoun production is examined through an elicited production method in pre-school- and primary school-aged groups of Italian children with specific language impairment (SLI) to establish whether there is an improvement from age 5 years to age 7 years and whether there are qualitative differences in the two groups' responses. It was found that 5- and 7-year-old Italian children with SLI produce fewer third-person DO clitics than same-age peers. The kind of responses they provide changes: at 5 years, children with SLI tend to omit clitics, while at 7 years, they use a full noun. Production of third-person DO clitics is a persistent challenge for children with SLI and is confirmed to be a good clinical marker both at 5 and 7 years of age.

Changes in the fertility of a leached chernozem under different primary tillage technologies

Science.gov (United States)

Korolev, V. A.; Gromovik, A. I.; Borontov, O. K.

2016-01-01

Changes in the fertility of a leached chernozem under different tillage technologies (moldboard, non-inversive, and combined tillage) were studied in a multifactor stationary field experiment established in 1985 in Voronezh oblast on a low-humus medium-deep light clayey leached chernozem. The nine-field rotation of cereals and sugar beet was practiced. It was found that the major parameters of soil fertility—the content and qualitative composition of humus and the physicochemical and physical properties of the chernozem—remained relatively stable independently from the applied primary tillage technologies. However, taking into account economic characteristics (crop yields, production costs, energy expenses, etc.), the combined tillage system proved to be most efficient. It can be recommended for cereals-sugar beet rotation systems in the central chernozemic region, as it ensures the highest efficiency of crop growing and preserves the fertility of leached chernozems.

Linking climate, gross primary productivity, and site index across forests of the western United States

Science.gov (United States)

Aaron R. Weiskittel; Nicholas L. Crookston; Philip J. Radtke

2011-01-01

Assessing forest productivity is important for developing effective management regimes and predicting future growth. Despite some important limitations, the most common means for quantifying forest stand-level potential productivity is site index (SI). Another measure of productivity is gross primary production (GPP). In this paper, SI is compared with GPP estimates...

Twelve-month space changes after premature loss of a primary maxillary first molar.

Science.gov (United States)

Lin, Yai-Tin; Lin, Wen-Hsien; Lin, Yng-Tzer J

2011-05-01

Many early investigations concerning space changes following premature extraction of primary molars had a cross-sectional design, a small sample size, and a somewhat crude methodology, which may have led to misunderstandings. The aim of this study was to use established longitudinal data to investigate ongoing (12-month) dental-arch space problems arising as a result of premature loss of a primary maxillary first molar. Thirteen children (mean ± SD age at time of tooth extraction, 6.0 ± 0.74 years) with unilateral premature loss of a primary maxillary first molar were selected for this study. Maxillary dental study casts were obtained from participants 2 or 3 days after the tooth was removed, as well as at a follow-up appointment 12 months later. Six reference lines were measured on the study cast: D + E space, arch width, arch length, intercanine width, intercanine length, and arch perimeter. For each participant, the D + E space of the contralateral intact primary molar served as a control. A paired t-test was used to compare the cast measurements between initial examination and 12-month follow-up. A t-test was used to compare D + E space changes with those of the control group. The D + E space of the extraction side after 12 months was significantly smaller than that of the control side (P 0.05). The 12-month space changes in the maxillary dental arch after premature loss of a primary maxillary first molar consist mainly of distal drift of the primary canine toward the extraction site. Mesial movement of permanent molars or tilting of the primary molars did not occur. An increased arch dimension was found especially in the anterior segment (intercanine width and length). There is no need for the use of space maintainers from the results in this study in cases of premature loss of a primary first molar. © 2010 The Authors. International Journal of Paediatric Dentistry © 2010 BSPD, IAPD and Blackwell Publishing Ltd.

Preparation of a primary target for the production of fission products in a nuclear reactor

International Nuclear Information System (INIS)

Arino, H.; Cosolito, F.J.; George, K.D.; Thornton, A.K.

1976-01-01

A primary target for the production of fission products in a nuclear reactor, such as uranium or plutonium fission products, is comprised of an enclosed, cylindrical vessel, preferably comprised of stainless steel, having a thin, continuous, uniform layer of fissionable material, integrally bonded to its inner walls and a port permitting access to the interior of the vessel. A process is also provided for depositing uranium material on to the inner walls of the vessel. Upon irradiation of the target with neutrons from a nuclear reactor, radioactive fission products, such as molybdenum-99, are formed, and thereafter separated from the target by the introduction of an acidic solution through the port to dissolve the irradiated inner layer. The irradiation and dissolution are thus effected in the same vessel without the necessity of transferring the fissionable material and fission products to a separate chemical reactor. Subsequently, the desired isotopes are extracted and purified. Molybdenum-99 decays to technetium-99m which is a valuable medical diagnostic radioisotope. 3 claims, 1 drawing figure

Patterns of primary production in the Red Sea

Digital Repository Service at National Institute of Oceanography (India)

Qurban, M.A.; Wafar, M.; Jyothibabu, R.; Manikandan, K.P.

for bio- phic stations occupied in e Indian Ocean (source - et al., 1995), remotely-sensed (CZCS) chlorophyll data were used to make deductions on rates of primary production at basin-scale. The conclusion consistently arrived at from all earlier studies... acquired along the axis of the basin in the 2013 cruise, Wafar et al. (2016a) identified alternating zonal currents at six locations – 18–18.5°N, 19–20.5°N, 22°N, 24°N, 24.5°N and 26°N - and concluded that they represent three successive anticyclonic cells...

Vegetation-specific model parameters are not required for estimating gross primary production

Czech Academy of Sciences Publication Activity Database

Yuan, W.; Cai, W.; Liu, S.; Dong, W.; Chen, J.; Altaf Arain, M.; Blanken, P. D.; Cescatti, A.; Wohlfahrt, G.; Georgiadis, T.; Genesio, L.; Gianelle, D.; Grelle, A.; Kiely, G.; Knohl, A.; Liu, D.; Marek, Michal V.; Merbold, L.; Montagnani, L.; Panferov, O.; Peltoniemi, M.; Rambal, S.; Raschi, A.; Varlagin, A.; Xia, J.

2014-01-01

Roč. 292, NOV 24 2014 (2014), s. 1-10 ISSN 0304-3800 Institutional support: RVO:67179843 Keywords : light use efficiency * gross primary production * model parameters Subject RIV: EH - Ecology, Behaviour Impact factor: 2.321, year: 2014

Productivity Change and Externalities

DEFF Research Database (Denmark)

Kravtsova, Victoria

2014-01-01

This paper contributes to the analysis of the impact of externalities on the host country's total factor productivity by taking into account different dimensions of spillover effects. Namely, engagement in exporting and foreign ownership is generally perceived as being beneficial to individual...... firms and the economy as a whole. The approach used in the current research accounts for different internal as well as external factors that individual firms face and evaluates the effect on changes in productivity, technology as well as the efficiency of domestic firms. The empirical analysis focuses...... on Hungary. While the country leads the group of post-socialist countries in the amount of attracted foreign direct investments (FDI) the effect of this policy on the economy remains unclear. The research finds that different externalities play a different role in productivity, technological and efficiency...

Classification and calculation of primary failure modes in bread production line

International Nuclear Information System (INIS)

Tsarouhas, Panagiotis H.

2009-01-01

In this study, we describe the classification methodology over a 2-year period of the primary failure modes in categories based on failure data of bread production line. We estimate the probabilities of these categories applying the chi-square goodness of fit test, and we calculate their joint probabilities of mass function at workstation and line level. Then, we present numerical examples in order to predict the causes and frequencies of breakdowns for workstations and for the entire bread production line that will occur in the future. The methodology is meant to guide bread and bakery product manufacturers, improving the operation of the production lines. It can also be a useful tool to maintenance engineers, who wish to analyze and improve the reliability and efficiency of the manufacturing systems

The potential effects of climate change on the distribution and productivity of Cunninghamia lanceolata in China.

Science.gov (United States)

Liu, Yupeng; Yu, Deyong; Xun, Bin; Sun, Yun; Hao, Ruifang

2014-01-01

Climate changes may have immediate implications for forest productivity and may produce dramatic shifts in tree species distributions in the future. Quantifying these implications is significant for both scientists and managers. Cunninghamia lanceolata is an important coniferous timber species due to its fast growth and wide distribution in China. This paper proposes a methodology aiming at enhancing the distribution and productivity of C. lanceolata against a background of climate change. First, we simulated the potential distributions and establishment probabilities of C. lanceolata based on a species distribution model. Second, a process-based model, the PnET-II model, was calibrated and its parameterization of water balance improved. Finally, the improved PnET-II model was used to simulate the net primary productivity (NPP) of C. lanceolata. The simulated NPP and potential distribution were combined to produce an integrated indicator, the estimated total NPP, which serves to comprehensively characterize the productivity of the forest under climate change. The results of the analysis showed that (1) the distribution of C. lanceolata will increase in central China, but the mean probability of establishment will decrease in the 2050s; (2) the PnET-II model was improved, calibrated, and successfully validated for the simulation of the NPP of C. lanceolata in China; and (3) all scenarios predicted a reduction in total NPP in the 2050s, with a markedly lower reduction under the a2 scenario than under the b2 scenario. The changes in NPP suggested that forest productivity will show a large decrease in southern China and a mild increase in central China. All of these findings could improve our understanding of the impact of climate change on forest ecosystem structure and function and could provide a basis for policy-makers to apply adaptive measures and overcome the unfavorable influences of climate change.

Alaska's timber harvest and forest products industry, 2005

Science.gov (United States)

Jeff M. Halbrook; Todd A. Morgan; Jason P. Brandt; Charles E. Keegan; Thale Dillon; Tara M. Barrett

2009-01-01

This report traces the flow of timber harvested in Alaska during calendar year 2005, describes the composition and operations of the state's primary forest products industry, and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as trends in timber harvest, production, and sales of primary wood products....

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).

Robust Estimation of Productivity Changes in Japanese Shinkin Banks

Directory of Open Access Journals (Sweden)

Jianzhong DAI

2014-05-01

Full Text Available This paper estimates productivity changes in Japanese shinkin banks during the fiscal years 2001 to 2008 using the Malmquist index as the measure of productivity change. Data envelopment analysis (DEA is used to estimate the index. We also apply a smoothed bootstrapping approach to set up confidence intervals for estimates and study their statistical characteristics. By analyzing estimated scores, we identify trends in productivity changes in Japanese shinkin banks during the study period and investigate the sources of these trends. We find that in the latter half of the study period, productivity has significantly declined, primarily because of deterioration in technical efficiency, but scale efficiency has been significantly improved. Grouping the total sample according to the levels of competition reveals more details of productivity changes in shinkin banks.

Testing the applicability of BIOME-BGC to simulate beech gross primary production in Europe using a new continental weather dataset

OpenAIRE

Chiesi , Marta; Chirici , Gherardo; Marchetti , Marco; Hasenauer , Hubert; Moreno , Adam; Knohl , Alexander; Matteucci , Giorgio; Pilegaard , Kim; Granier , André; Longdoz , Bernard; Maselli , Fabio

2016-01-01

Key message A daily 1-km Pan-European weather dataset can drive the BIOME-BGC model for the estimation of current and future beech gross primary production (GPP). Annual beech GPP is affected primarily by spring temperature and more irregularly by summer water stress. [br/] Context The spread of beech forests in Europe enhances the importance of modelling and monitoring their growth in view of ongoing climate changes. [br/] Aims The current paper assesses the capability o...

Isolating and Quantifying the Effects of Climate and CO2 Changes (1980–2014 on the Net Primary Productivity in Arid and Semiarid China

Directory of Open Access Journals (Sweden)

Xia Fang

2017-02-01

Full Text Available Although the net primary productivity (NPP of arid/semiarid ecosystem is generally thought to be controlled by precipitation, other factors like CO2 fertilization effect and temperature change may also have important impacts, especially in the cold temperate areas of the northern China, where significant warming was reported in the recent decades. However, the impacts of climate and atmospheric CO2 changes to the NPP dynamics in the arid and semiarid areas of China (ASA-China is still unclear, hindering the development of climate adaptation strategy. Based on numeric experiments and factorial analysis, this study isolated and quantified the effects of climate and CO2 changes between 1980–2014 on ASA-China’s NPP, using the Arid Ecosystem Model (AEM that performed well in predicting ecosystems’ responses to climate/CO2 change according to our evaluation based on 21 field experiments. Our results showed that the annual variation in NPP was dominated by changes in precipitation, which reduced the regional NPP by 10.9 g·C/(m2·year. The precipitation-induced loss, however, has been compensated by the CO2 fertilization effect that increased the regional NPP by 14.9 g·C/(m2·year. The CO2 fertilization effect particularly benefited the extensive croplands in the Northern China Plain, but was weakened in the dry grassland of the central Tibetan Plateau due to suppressed plant activity as induced by a drier climate. Our study showed that the climate change in ASA-China and the ecosystem’s responses were highly heterogeneous in space and time. There were complex interactive effects among the climate factors, and different plant functional types (e.g., phreatophyte vs. non-phreatophyte could have distinct responses to similar climate change. Therefore, effective climate-adaptive strategies should be based on careful analysis of local climate pattern and understanding of the characteristic responses of the dominant species. Particularly, China�

Changes in production efficiency in China identification and measuring

CERN Document Server

Xu, Bing; Watada, Junzo

2014-01-01

Evaluating  Production Efficiency in China examines production from engineering and statistics perspectives rather than from economics and mathematics perspectives. The authors present an observable benchmark as the criterion of the production efficiency to replace the unobservable production frontier surface. This book discusses several different computing technologies, controllable variable as a path of identification, changes in production efficiency by decision making on specific operating conditions, and optimal resource allocation. The book provides a channel to tap inside the success stories of China, exploiting the way of changes in production efficiency during China’s development in the past 30 years. This book examines the concepts and realization of production efficiencies across all areas of the economy. Also the book provides the perspective of foreign direct investment (FDI) absorption to identify how Chinese economy changes in production efficiency.

Counterintuitive effects of global warming-induced wind patterns on primary production in the Northern Humboldt Current System.

Science.gov (United States)

Mogollón, Rodrigo; R Calil, Paulo H

2018-04-14

It has been hypothesized that global warming will strengthen upwelling-favorable winds in the Northern Humboldt Current System (NHCS) as a consequence of the increase of the land-sea thermal gradient along the Peruvian coast. The effect of strengthened winds in this region is assessed with the use of a coupled physical-biogeochemical model forced with projected and climatological winds. Strengthened winds induce an increase in primary production of 2% per latitudinal degree from 9.5°S to 5°S. In some important coastal upwelling sites primary production is reduced. This is due to a complex balance between nutrient availability, nutrient use efficiency, as well as eddy- and wind-driven factors. Mesoscale activity induces a net offshore transport of inorganic nutrients, thus reducing primary production in the coastal upwelling region. Wind mixing, in general disadvantageous for primary producers, leads to shorter residence times in the southern and central coastal zones. Overall, instead of a proportional enhancement in primary production due to increased winds, the NHCS becomes only 5% more productive (+5 mol C m -2 year -1 ), 10% less limited by nutrients and 15% less efficient due to eddy-driven effects. It is found that regions with a initial strong nutrient limitation are more efficient in terms of nutrient assimilation which makes them more resilient in face of the acceleration of the upwelling circulation. © 2018 John Wiley & Sons Ltd.

The Change Path of Agricultural Production Outsourcing

Directory of Open Access Journals (Sweden)

Juan Zhang

2014-04-01

Full Text Available The system of agricultural production outsourcing is a breakpoint for the development of agriculture and immigration worker’s urbanization. The analysis based on framework of the Institutional Change reveals that as a whole,the outsourcing system of agricultural production improves the welfare of society effectively. To some extents,it also can solve the problem of food security. The rural transferring labor-forces who realize the institutional change in the initial stage are is the first Action Group to gain the potential benefits. Local governments are a breakpoint of induced institutional change, which find potential benefits and then change the role of system changes. The central government is in dominant statue during the whole change. The outsourcing is a kind of improvement to the Family Contracted System, also an adaption to an imperfect Chinese rural social security. So the outsourcing has a positive meaning in the rural area.

Behaviour of fission products in PWR primary coolant and defected fuel rods evaluation

International Nuclear Information System (INIS)

Bourgeois, P.; Stora, J.P.

1979-01-01

The activity surveillance of the PWR primary coolant by γ spectometry gives some informations on fuel failures. The activity of different nuclides e.g. Xenons, Kryptons, Iodines, can be correlated with the number of the defected fuel rods. Therefore the precharacterization with eventually a prelocalization of the related fuel assemblies direct the sipping-test and allows a saving of time during refueling. A model is proposed to calculate the number of the defected rods from the activity measurements of the primary coolant. A semi-empirical model of the release of the fission products has been built from the activity measurements of the primary coolant in a 900 MWe PWR. This model allows to calculate the number of the defected rods and also a typical parameter of the mean damage. Fission product release is described by three stages: release from uranium dioxide, transport across the gas gap and behaviour in the primary coolant. The model of release from the oxide considers a diffusion process in the grains with trapping. The release then occurs either directly to free surfaces or with a delay due to a transit into closed porosity of the oxide. The amount released is the same for iodine and rare gas. With the gas gap transit is associated a transport time and a probability of trapping for the iodines. In the primary coolant the purification and the radioactive decay are considered. (orig.)

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.

Performance of a two-leaf light use efficiency model for mapping gross primary productivity against remotely sensed sun-induced chlorophyll fluorescence data.

Science.gov (United States)

Zan, Mei; Zhou, Yanlian; Ju, Weimin; Zhang, Yongguang; Zhang, Leiming; Liu, Yibo

2018-02-01

Estimating terrestrial gross primary production is an important task when studying the carbon cycle. In this study, the ability of a two-leaf light use efficiency model to simulate regional gross primary production in China was validated using satellite Global Ozone Monitoring Instrument - 2 sun-induced chlorophyll fluorescence data. The two-leaf light use efficiency model was used to estimate daily gross primary production in China's terrestrial ecosystems with 500-m resolution for the period from 2007 to 2014. Gross primary production simulated with the two-leaf light use efficiency model was resampled to a spatial resolution of 0.5° and then compared with sun-induced chlorophyll fluorescence. During the study period, sun-induced chlorophyll fluorescence and gross primary production simulated by the two-leaf light use efficiency model exhibited similar spatial and temporal patterns in China. The correlation coefficient between sun-induced chlorophyll fluorescence and monthly gross primary production simulated by the two-leaf light use efficiency model was significant (pproduction simulated by the two-leaf light use efficiency model were similar in spring and autumn in most vegetated regions, but dissimilar in winter and summer. The spatial variability of sun-induced chlorophyll fluorescence and gross primary production simulated by the two-leaf light use efficiency model was similar in spring, summer, and autumn. The proportion of spatial variations of sun-induced chlorophyll fluorescence and annual gross primary production simulated by the two-leaf light use efficiency model explained by ranged from 0.76 (2011) to 0.80 (2013) during the study period. Overall, the two-leaf light use efficiency model was capable of capturing spatial and temporal variations in gross primary production in China. However, the model needs further improvement to better simulate gross primary production in summer. Copyright © 2017 Elsevier B.V. All rights reserved.

Developmental changes in brain activation involved in the production of novel speech sounds in children.

Science.gov (United States)

Hashizume, Hiroshi; Taki, Yasuyuki; Sassa, Yuko; Thyreau, Benjamin; Asano, Michiko; Asano, Kohei; Takeuchi, Hikaru; Nouchi, Rui; Kotozaki, Yuka; Jeong, Hyeonjeong; Sugiura, Motoaki; Kawashima, Ryuta

2014-08-01

Older children are more successful at producing unfamiliar, non-native speech sounds than younger children during the initial stages of learning. To reveal the neuronal underpinning of the age-related increase in the accuracy of non-native speech production, we examined the developmental changes in activation involved in the production of novel speech sounds using functional magnetic resonance imaging. Healthy right-handed children (aged 6-18 years) were scanned while performing an overt repetition task and a perceptual task involving aurally presented non-native and native syllables. Productions of non-native speech sounds were recorded and evaluated by native speakers. The mouth regions in the bilateral primary sensorimotor areas were activated more significantly during the repetition task relative to the perceptual task. The hemodynamic response in the left inferior frontal gyrus pars opercularis (IFG pOp) specific to non-native speech sound production (defined by prior hypothesis) increased with age. Additionally, the accuracy of non-native speech sound production increased with age. These results provide the first evidence of developmental changes in the neural processes underlying the production of novel speech sounds. Our data further suggest that the recruitment of the left IFG pOp during the production of novel speech sounds was possibly enhanced due to the maturation of the neuronal circuits needed for speech motor planning. This, in turn, would lead to improvement in the ability to immediately imitate non-native speech. Copyright © 2014 Wiley Periodicals, Inc.

Primary, new and export production in the NW Pacific subarctic gyre during the vertigo K2 experiments

Science.gov (United States)

Elskens, M.; Brion, N.; Buesseler, K.; Van Mooy, B. A. S.; Boyd, P.; Dehairs, F.; Savoye, N.; Baeyens, W.

2008-07-01

This paper presents results on tracer experiments using 13C and 15N to estimate uptake rates of dissolved inorganic carbon (DIC) and nitrogen (DIN). Experiments were carried out at station K2 (47°N, 161°E) in the NW Pacific subarctic gyre during July-August 2005. Our goal was to investigate relationships between new and export production. New production was inferred from the tracer experiments using the f ratio concept (0-50 m); while export production was assessed with neutrally buoyant sediment traps (NBSTs) and the e ratio concept (at 150 m). During trap deployments, K2 was characterized both by changes in primary production (523-404 mg C m -2 d -1), new production (119-67 mg C m -2 d -1), export production (68-24 mg C m -2 d -1) and phytoplankton composition (high to low proportion of diatoms). The data indicate that 17-23% of primary production is exportable to deeper layers ( f ratio) but only 6-13% collected as a sinking particle flux at 150 m ( e ratio). Accordingly, >80% of the carbon fixed by phytoplankton would be mineralized in the upper 50 m (1- f), while <11% would be within 50-150 m ( f- e). DIN uptake flux amounted to 0.5 mM m -2 h -1, which was equivalent to about 95% particulate nitrogen (PN) remineralized and/or grazed within the upper 150 m. Most of the shallow PN remineralization occurred just above the depth of the deep chlorophyll maximum (DCM), where a net ammonium production was measured. Below the DCM, while nitrate uptake rates became negligible because of light limitation, ammonium uptake did continue to be significant. The uptake of ammonium by heterotrophic bacteria was estimated to be 14-17% of the DIN assimilation. Less clear are the consequences of this uptake on the phytoplankton community and biogeochemical processes, e.g. new production. It was suggested that competition for ammonium could select for small cells and may force large diatoms to use nitrate. This implies that under Fe stress as observed here, ammonium uptake is

Temperature dependence of CO2-enhanced primary production in the European Arctic Ocean, supplement to: Holding, Johnna; Duarte, Carlos M; Sanz-Martín, Marina; Mesa, E; Arrieta, J M; Chierici, Melissa; Hendriks, Iris; García-Corral, L S; Regaudie-de-Gioux, A; Delgado, A; Reigstad, M; Wassmann, P; Agustí, Susana (2015): Temperature dependence of CO2-enhanced primary production in the European Arctic Ocean. Nature Climate Change, 5(12), 1079-1082

KAUST Repository

Holding, Johnna; Duarte, Carlos M.; Sanz-Martí n, Marina; Mesa, E; Arrieta, J M; Chierici, Melissa; Hendriks, Iris; Garcí a-Corral, L S; Regaudie-de-Gioux, A; Delgado, A; Reigstad, M; Wassmann, P; Agusti, Susana

2016-01-01

should lead to increased rates of planktonic primary production. Yet, simultaneous assessment of warming and increased CO2 on primary production in the Arctic has not been conducted. Here we test the expectation that CO2-enhanced gross primary production

Evaluation of Net Primary Productivity and Carbon Allocation to Different Parts of Corn in Different Tillage and Nutrient Management Systems

Directory of Open Access Journals (Sweden)

esmat mohammadi

2017-09-01

and biochar can increase belowground net primary production and carbon allocation to belowground organs and by adding root residues to the soil can retain roots carbon and prevent its release into the atmosphere. Therefore with reduction of CO2 amount in atmosphere, climate change and global warming be reduced.

Software sensor for primary metabolite production case of alcoholic fermentation

Energy Technology Data Exchange (ETDEWEB)

Roux, G.; Dahhou, B.; Queinnec, I. [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France)]|[Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France); Goma, G. [Institut National des Sciences Appliquees (INSA), 31 - Toulouse (France)

1995-12-31

This paper investigate the application of an observer for state and parameter estimation to batch, continuous and fed batch fermentations for alcohol production taken as model for a primary metabolite production. This observer is provided to palliate the lack of suitable sensors for on-line biomass and ethanol concentrations measurements and to estimate the time varying specific growth rate. Estimates are obtained from an interlaced structure filter based on a `modified extended Kalman filter` by using on-line measurements of carbon dioxide outflow rate and substrate concentration. The filter algorithm was tested during batch, continuous and fed batch fermentation processes. The filter behaviour observed in the experiments gives good results with an agreement theory/practice. (authors) 18 refs.

Linking primary production, climate and land use along an urban-wildland transect: a satellite view

International Nuclear Information System (INIS)

Hu Yonghong; Jia Gensuo; Guo Huadong

2009-01-01

Variation of green vegetation cover influences local climate dynamics, exchange of water-heat between land and atmosphere, and hydrological processes. However, the mechanism of interaction between vegetation and local climate change in subtropical areas under climate warming and anthropogenic disturbances is poorly understood. We analyzed spatial-temporal trends of vegetation with moderate-resolution imaging spectroradiometer (MODIS) vegetation index datasets over three sections, namely urban, urban-rural fringe and wildland along an urban-wildland transect in a southern mega-city area in China from 2000-2008. The results show increased photosynthetic activity occurred in the wildland and the stable urban landscape in correspondence to the rising temperature, and a considerable decrease of vegetation activity in the urban-rural fringe area, apparently due to urban expansion. On analyzing the controlling factors of climate change and human drivers of vegetation cover change, we found that temperature contributed to vegetation growth more than precipitation and that rising temperature accelerated plant physiological activity. Meanwhile, human-induced dramatic modification of land cover, e.g. conversion of natural forest and cropland to built-up areas in the urban-rural fringe, has caused significant changes of green vegetation fraction and overall primary production, which may further influence local climate.

Studies on the primary productivity of a polluted mangrove pond in ...

African Journals Online (AJOL)

The primary productivity of a polluted mangrove pond in Lagos was investigated for six months (October 2010-March 2011) using the chlorophyll-a method. Air and water temperatures were high (≥21°C) while transparency was lower than 11.5 cm at the mangrove pond. Total suspended solids were ≥2.0 mg/L while total ...

Major activated corrosion products cobalt, silver and antimony in the primary coolant of PWR power plants

International Nuclear Information System (INIS)

Xu Mingxia

2012-01-01

The production of the major activated corrosion products such as cobalt, silver and antimony in the primary coolant of PWR power plants and the impacts on the increase of the dose rates caused by these corrosion products during the shutdown are described in the paper. Investigating the corrosion product behavior during the operation and shutdown periods aims at detecting the appearance of these radiological pollutants in the early time and searching relevant solutions that may enable eventually to decrease the dose rate. The solutions may include: Replacing critical material in the primary system's equipment and components, which contact with primary coolant circuit to possibly limit the source term, Elaborating strictly the specific chemical and shutdown procedure to optimize the purification capacity and to minimize the over-contaminations; Improving purification techniques according to the real operation circumstance, and limiting the impacts of these pollutants. It is obvious in the real practices that implementing appropriate solution will be benefit to decrease or limit the pollutants species like cobalt, silver and antimony. (author)

Lifestyle counseling in primary care: opportunities and challenges for changing practice.

Science.gov (United States)

Sargeant, Joan; Valli, Michel; Ferrier, Suzanne; MacLeod, Heather

2008-01-01

Many patients today have health concerns related to lifestyle factors. This has created a situation where physicians are regularly confronted with the challenge of how to conduct lifestyle counseling with patients. Specific strategies can enable physicians to more effectively navigate this complex area of communication with patients, improving patient response in adopting healthy behaviours and increasing physician satisfaction with this task. To evaluate the impact of a lifestyle counseling workshop incorporating the motivational enhancement and transtheoretical models upon primary care clinicians' counseling practice patterns, especially communication and counseling skills, and attitudes toward lifestyle counseling. This study used a mixed method research design. Forty-three clinicians completed a post-workshop evaluation and identified intended changes to practice following the workshop. Twelve participated in interviews several months later to explore the kinds of changes made and influences upon them. Forty-one (95.3%) questionnaire respondents reported an intention to change their practice. Main changes reported were: asking more questions, listening more, assessing patients' readiness to change, tailoring counseling to patients' readiness to change. They seemed to have acquired and retained new knowledge and most were able to apply the new skills in their practices. Many reported feeling more comfortable and/or confident when interacting with patients in need of lifestyle change. But, time constraints, comfort with current skills, lack of self-efficacy, and fears of missing opportunities to influence patients, moderated participants' ability to adopt and maintain new approaches. While primary care clinicians can successfully learn specific lifestyle counseling skills and incorporate them into their practice following a two-hour evidence-based workshop, individual, educational and system factors can interfere.

Joint control of terrestrial gross primary productivity by plant phenology and physiology

NARCIS (Netherlands)

Xia, J.; Niu, S.; Ciais, P.; Janssens, I.A.; Chen, J.; Ammann, C.; Arain, A.; Blanken, P.D.; Cescatti, A.; Moors, E.J.

2015-01-01

Terrestrial gross primary productivity (GPP) varies greatly over time and space. A better understanding of this variability is necessary for more accurate predictions of the future climate–carbon cycle feedback. Recent studies have suggested that variability in GPP is driven by a broad range of

Metrology requirements for the serial production of ELT primary mirror segments

Science.gov (United States)

Rees, Paul C. T.; Gray, Caroline

2015-08-01

The manufacture of the next generation of large astronomical telescopes, the extremely large telescopes (ELT), requires the rapid manufacture of greater than 500 1.44m hexagonal segments for the primary mirror of each telescope. Both leading projects, the Thirty Meter Telescope (TMT) and the European Extremely Large Telescope (E-ELT), have set highly demanding technical requirements for each fabricated segment. These technical requirements, when combined with the anticipated construction schedule for each telescope, suggest that more than one optical fabricator will be involved in the delivery of the primary mirror segments in order to meet the project schedule. For one supplier, the technical specification is challenging and requires highly consistent control of metrology in close coordination with the polishing technologies used in order to optimize production rates. For production using multiple suppliers, however the supply chain is structured, consistent control of metrology along the supply chain will be required. This requires a broader pattern of independent verification than is the case of a single supplier. This paper outlines the metrology requirements for a single supplier throughout all stages of the fabrication process. We identify and outline those areas where metrology accuracy and duration have a significant impact on production efficiency. We use the challenging ESO E-ELT technical specification as an example of our treatment, including actual process data. We further develop this model for the case of a supply chain consisting of multiple suppliers. Here, we emphasize the need to control metrology throughout the supply chain in order to optimize net production efficiency.

Primary production and algae diversity vs. pollution in xochimilco wet-lands

Energy Technology Data Exchange (ETDEWEB)

Pedroza-Pichardo, R.; Hernandez-Delgadillo, R.; Boll-Arguello, G.

2009-07-01

Xochimilco is an ancient endorheic lake located in the Valley of Mexico. Due to its shallow water and the freshwater springs that lined the canals, they are surround raised agricultural fields called chinampas. Since the Valley of Mexico was originally wetlands, the chinampas were the most productive means of agricultural production. Xochimilco are considered one of the most important urban lungs in Mexico City. However, it is not clear how the huge urbanization around is to know if there is a correlation between primary production (PP), algae diversity, BOD{sub 5} and faecal coliforms. Sample collection was done every month over a year at six different canals named: Embarcadero Celada, Embarcadero Nuevo Nativitas, Canal Las Abejas, Canal Zacapa, Canal Santo Domingo y Canal Nacional. (Author)

Primary production and algae diversity vs. pollution in xochimilco wet-lands

International Nuclear Information System (INIS)

Pedroza-Pichardo, R.; Hernandez-Delgadillo, R.; Boll-Arguello, G.

2009-01-01

Xochimilco is an ancient endorheic lake located in the Valley of Mexico. Due to its shallow water and the freshwater springs that lined the canals, they are surround raised agricultural fields called chinampas. Since the Valley of Mexico was originally wetlands, the chinampas were the most productive means of agricultural production. Xochimilco are considered one of the most important urban lungs in Mexico City. However, it is not clear how the huge urbanization around is to know if there is a correlation between primary production (PP), algae diversity, BOD 5 and faecal coliforms. Sample collection was done every month over a year at six different canals named: Embarcadero Celada, Embarcadero Nuevo Nativitas, Canal Las Abejas, Canal Zacapa, Canal Santo Domingo y Canal Nacional. (Author)

Space changes after premature loss of the mandibular primary first molar: a longitudinal study.

Science.gov (United States)

Lin, Y T; Chang, L C

1998-01-01

The purpose of this study was to evaluate the space changes after premature loss of the primary mandibular first molar. Twenty-one children (12 boys and 9 girls), with premature loss of the primary mandibular first molar, were selected from the children's dental clinic for this study. The age ranged from 5.1 to 7.2 years with an average of 6 years and 11 months. Mandibular study casts were made from alginate impression for each initial examination and a follow-up examination eight months later. Four measurements including D+E (first and second primary molars) space, arch width, arch length and arch perimeter were tested for comparisons between the initial examination and the follow-up examination eight months later. The D+E space of intact primary molars served as a control. The results showed that the D+E space on the extraction side after the follow-up examination eight months later was significantly shorter than the control side (p = 0.025) and less than the initial D+E space (p 0.05). It is concluded that the space change after the eruption of the first permanent molar in the mandible is mostly distal movement of the primary cuspid during the early stage of premature loss of the primary first molar.

Fission product plateout and liftoff in the MHTGR primary system: A review

International Nuclear Information System (INIS)

Wichner, R.P.

1991-04-01

A review is presented of the technical basis for predicting radioactivity release resulting from depressurization of an MHTGR primary system. Consideration is restricted to so called dry events with no involvement of the steam system. The various types of deposition mechanisms effective for iodine, cesium, strontium, and silver are discussed in terms of their chemical characteristics and the nature of the materials in the primary system. Emphasis is given to iodine behavior, including means for estimating the quantity available for release, the types of plateout locations in the primary system, and the effect of dust on distribution and release. The behavior of fission products cesium, strontium, and silver in such accidents is presented qualitatively. A major part of the review deals with expected dust levels, types, and transport. Available information on the level and nature of dust in the HTGR primary system is reviewed. A summary is presented of dust deposition and liftoff mechanisms. It was concluded that recent approaches to dust liftoff modeling, based on turbulent burst concepts for removal from surfaces, probably offer advantages over the current shear ratio approach. This study concludes that iodine releases from dry depressurization events are likely to be extremely low, on the order of millicuries, due to a predictably low degree of chemical desorption, a low degree of dust liftoff, and a low involvement of iodine with dust. It was also concluded that deposition mechanisms controlling the distribution of fission product material in the primary system, and hence also controlling the degree of liftoff, depend strongly on the chemical nature of the individual elements. Therefore contrary to the current practice, both plateout and liftoff models should reflect those unique chemical and physical properties. 56 refs., 16 figs., 23 tabs

Analysis of T Cell Subsets in Adult Primary/Idiopathic Minimal Change Disease: A Pilot Study

Directory of Open Access Journals (Sweden)

Francisco Salcido-Ochoa

2017-01-01

Full Text Available Aim. To characterise infiltrating T cells in kidneys and circulating lymphocyte subsets of adult patients with primary/idiopathic minimal change disease. Methods. In a cohort of 9 adult patients with primary/idiopathic minimal change recruited consecutively at disease onset, we characterized (1 infiltrating immune cells in the kidneys using immunohistochemistry and (2 circulating lymphocyte subsets using flow cytometry. As an exploratory analysis, association of the numbers and percentages of both kidney-infiltrating immune cells and the circulating lymphocyte subsets with kidney outcomes including deterioration of kidney function and proteinuria, as well as time to complete clinical remission up to 48 months of follow-up, was investigated. Results. In the recruited patients with primary/idiopathic minimal change disease, we observed (a a dominance of infiltrating T helper 17 cells and cytotoxic cells, comprising cytotoxic T cells and natural killer cells, over Foxp3+ Treg cells in the renal interstitium; (b an increase in the circulating total CD8+ T cells in peripheral blood; and (c an association of some of these parameters with kidney function and proteinuria. Conclusions. In primary/idiopathic minimal change disease, a relative numerical dominance of effector over regulatory T cells can be observed in kidney tissue and peripheral blood. However, larger confirmatory studies are necessary.

Drivers of Changes in Product Development Rules

DEFF Research Database (Denmark)

Christiansen, John K.; Varnes, Claus J.

2015-01-01

regimes. However, the analysis here indicates that there are different drivers, both internal and external, that cause companies to adopt new rules or modify their existing ones, such as changes in organizational structures, organizational conflicts, and changes in ownership or strategy. In addition......Purpose: - The purpose of this research is to investigate the drivers that induce companies to change their rules for managing product development. Most companies use a form of rule-based management approach, but surprisingly little is known about what makes companies change these rules...... 10 years based on three rounds of interviews with 40 managers. Findings: - Previous research has assumed that the dynamics of product development rules are based on internal learning processes, and that increasingly competent management will stimulate the implementation of newer and more complex rule...

Nitrogen and carbon limitation of planktonic primary production and phytoplankton–bacterioplankton coupling in ponds on the McMurdo Ice Shelf, Antarctica

International Nuclear Information System (INIS)

Sorrell, Brian K; Safi, Karl; Hawes, Ian

2013-01-01

We compared planktonic primary and secondary production across twenty meltwater ponds on the surface of the McMurdo Ice Shelf in January 2007, including some ponds with basal brines created by meromictic stratification. Primary production ranged from 1.07 to 65.72 mgC m −3 h −1 in surface waters. In stratified ponds primary production was always more than ten times higher in basal brines than in the corresponding mixolimnion. Regression tree analysis (r 2 = 0.80) identified inorganic nitrogen (as NH 4 + ) as the main factor limiting planktonic primary production. However, there was also evidence of inorganic carbon co-limitation of photosynthesis in some of the more oligotrophic waters. Neither C nor N limited carbon fixation at [NH 4 –N] > 50 mg m −3 , with photoinhibition the factor most likely limiting photosynthesis under such conditions. Primary production was the only factor significantly correlated to bacterial production and the relationship (r 2 = 0.56) was non-linear. Nitrogen limitation and tight coupling of planktonic primary and bacterial production is surprising in these ponds, as all have large pools of dissolved organic carbon (1.2–260 g m −3 ) and organic nitrogen (all >130 mg m −3 ). The dissolved pools of organic carbon and nitrogen appear to be recalcitrant and bacterial production to be constrained by limited release of labile organics from phytoplankton. (letter)

Respiration of new and old carbon in the surface ocean: Implications for estimates of global oceanic gross primary productivity

Science.gov (United States)

Carvalho, Matheus C.; Schulz, Kai G.; Eyre, Bradley D.

2017-06-01

New respiration (Rnew, of freshly fixated carbon) and old respiration (Rold, of storage carbon) were estimated for different regions of the global surface ocean using published data on simultaneous measurements of the following: (1) primary productivity using 14C (14PP); (2) gross primary productivity (GPP) based on 18O or O2; and (3) net community productivity (NCP) using O2. The ratio Rnew/GPP in 24 h incubations was typically between 0.1 and 0.3 regardless of depth and geographical area, demonstrating that values were almost constant regardless of large variations in temperature (0 to 27°C), irradiance (surface to 100 m deep), nutrients (nutrient-rich and nutrient-poor waters), and community composition (diatoms, flagellates, etc,). As such, between 10 and 30% of primary production in the surface ocean is respired in less than 24 h, and most respiration (between 55 and 75%) was of older carbon. Rnew was most likely associated with autotrophs, with minor contribution from heterotrophic bacteria. Patterns were less clear for Rold. Short 14C incubations are less affected by respiratory losses. Global oceanic GPP is estimated to be between 70 and 145 Gt C yr-1.Plain Language SummaryHere we present a comprehensive coverage of ocean new and old respiration. Our results show that nearly 20% of oceanic gross primary production is consumed in the first 24 h. However, most (about 60%) respiration is of older carbon fixed at least 24 h before its consumption. Rates of new respiration relative to gross primary production were remarkably constant for the entire ocean, which allowed a preliminary estimation of global primary productivity as between 70 and 145 gt C yr-1.

Phytoplankton absorption predicts patterns in primary productivity in Australian coastal shelf waters

Science.gov (United States)

Robinson, C. M.; Cherukuru, N.; Hardman-Mountford, N. J.; Everett, J. D.; McLaughlin, M. J.; Davies, K. P.; Van Dongen-Vogels, V.; Ralph, P. J.; Doblin, M. A.

2017-06-01

The phytoplankton absorption coefficient (aPHY) has been suggested as a suitable alternate first order predictor of net primary productivity (NPP). We compiled a dataset of surface bio-optical properties and phytoplankton NPP measurements in coastal waters around Australia to examine the utility of an in-situ absorption model to estimate NPP. The magnitude of surface NPP (0.20-19.3 mmol C m-3 d-1) across sites was largely driven by phytoplankton biomass, with higher rates being attributed to the microplankton (>20 μm) size class. The phytoplankton absorption coefficient aPHY for PAR (photosynthetically active radiation; āPHY)) ranged from 0.003 to 0.073 m-1, influenced by changes in phytoplankton community composition, physiology and environmental conditions. The aPHY coefficient also reflected changes in NPP and the absorption model-derived NPP could explain 73% of the variability in measured surface NPP (n = 41; RMSE = 2.49). The absorption model was applied to two contrasting coastal locations to examine NPP dynamics: a high chlorophyll-high variation (HCHV; Port Hacking National Reference Station) and moderate chlorophyll-low variation (MCLV; Yongala National Reference Station) location in eastern Australia using the GIOP-DC satellite aPHY product. Mean daily NPP rates between 2003 and 2015 were higher at the HCHV site (1.71 ± 0.03 mmol C m-3 d-1) with the annual maximum NPP occurring during the austral winter. In contrast, the MCLV site annual NPP peak occurred during the austral wet season and had lower mean daily NPP (1.43 ± 0.03 mmol C m-3 d-1) across the time-series. An absorption-based model to estimate NPP is a promising approach for exploring the spatio-temporal dynamics in phytoplankton NPP around the Australian continental shelf.

Joint control of terrestrial gross primary productivity by plant phenology and physiology

DEFF Research Database (Denmark)

Xia, Jianyang; Niu, Shuli; Ciais, Philippe

2015-01-01

Terrestrial gross primary productivity (GPP) varies greatly over time and space. A better understanding of this variability is necessary for more accurate predictions of the future climate–carbon cycle feedback. Recent studies have suggested that variability in GPP is driven by a broad range of b...

Evaluation of MODIS gross primary productivity for Africa using eddy covariance data

CSIR Research Space (South Africa)

Sjöström, M

2013-04-01

Full Text Available MOD17A2 provides operational gross primary production (GPP) data globally at 1 km spatial resolution and 8-day temporal resolution. MOD17A2 estimates GPP according to the light use efficiency (LUE) concept assuming a fixed maximum rate of carbon...

Efficiency of chlorophyll in gross primary productivity: A proof of concept and application in crops.

Science.gov (United States)

Gitelson, Anatoly A; Peng, Yi; Viña, Andrés; Arkebauer, Timothy; Schepers, James S

2016-08-20

One of the main factors affecting vegetation productivity is absorbed light, which is largely governed by chlorophyll. In this paper, we introduce the concept of chlorophyll efficiency, representing the amount of gross primary production per unit of canopy chlorophyll content (Chl) and incident PAR. We analyzed chlorophyll efficiency in two contrasting crops (soybean and maize). Given that they have different photosynthetic pathways (C3 vs. C4), leaf structures (dicot vs. monocot) and canopy architectures (a heliotrophic leaf angle distribution vs. a spherical leaf angle distribution), they cover a large spectrum of biophysical conditions. Our results show that chlorophyll efficiency in primary productivity is highly variable and responds to various physiological and phenological conditions, and water availability. Since Chl is accessible through non-destructive, remotely sensed techniques, the use of chlorophyll efficiency for modeling and monitoring plant optimization patterns is practical at different scales (e.g., leaf, canopy) and under widely-varying environmental conditions. Through this analysis, we directly related a functional characteristic, gross primary production with a structural characteristic, canopy chlorophyll content. Understanding the efficiency of the structural characteristic is of great interest as it allows explaining functional components of the plant system. Copyright © 2016 Elsevier GmbH. All rights reserved.

Investigation of change in specifications during a product's lifecycle

DEFF Research Database (Denmark)

Sudin, Mohd Nizam Bin; Ahmed, Saeema

2009-01-01

design attributes likely be changed; the initiation of change and how change in specifications are described. For this purpose, document analysis for a complex product has been carried out. In total, 271 reports of change request of an aero-engine that were associated to change in specifications were......Engineering changes (ECs) constitutes a normal part of a product’s lifecycle. This paper aims to understand why changes are made to a product’s specification during a product’s lifecycle including understanding: the distribution of changes; the drivers for changes; how changes are discovered; which...... the request was initiated. The study showed that experience plays a vital role in discovering the need to change a complex product...

An improvement of satellite-based algorithm for gross primary production estimation optimized over Korea

Science.gov (United States)

Pi, Kyoung-Jin; Han, Kyung-Soo; Kim, In-Hwan; Kim, Sang-Il; Lee, Min-Ji

2011-11-01

Monitoring the global gross primary production (GPP) is relevant to understanding the global carbon cycle and evaluating the effects of interannual climate variation on food and fiber production. GPP, the flux of carbon into ecosystems via photosynthetic assimilation, is an important variable in the global carbon cycle and a key process in land surface-atmosphere interactions. The Moderate-resolution Imaging Spectroradiometer (MODIS) is one of the primary global monitoring sensors. MODIS GPP has some of the problems that have been proven in several studies. Therefore this study was to solve the regional mismatch that occurs when using the MODIS GPP global product over Korea. To solve this problem, we estimated each of the GPP component variables separately to improve the GPP estimates. We compared our GPP estimates with validation GPP data to assess their accuracy. For all sites, the correlation was close with high significance (R2 = 0.8164, RMSE = 0.6126 g.C.m-2.d-1, bias = -0.0271 g.C.m-2.d-1). We also compared our results to those of other models. The component variables tended to be either over- or under-estimated when compared to those in other studies over the Korean peninsula, although the estimated GPP was better. The results of this study will likely improve carbon cycle modeling by capturing finer patterns with an integrated method of remote sensing. Keywords: VEGETATION, Gross Primary Production, MODIS.

Climate change impacts on natural toxins in food production systems, exemplified by deoxynivalenol in wheat and diarrhetic shellfish toxins

DEFF Research Database (Denmark)

van der Fels-Klerx, H J; Olesen, Jørgen E; Naustvoll, L-J

2012-01-01

Climate change is expected to affect food and feed safety, including the occurrence of natural toxins in primary crop and seafood production; however, to date, quantitative estimates are scarce. This study aimed to estimate the impact of climate change effects on mycotoxin contamination of cereal...... on food safety hazards, rather than median or average values only. Furthermore, it is recommended to closely monitor levels of mycotoxins and marine biotoxins in the future, in particular related to risky situations associated with favourable climatic conditions for toxin producing organisms...

Using wood products to mitigate climate change: External costs and structural change

Energy Technology Data Exchange (ETDEWEB)

Sathre, Roger; Gustavsson, Leif [Ecotechnology, Mid Sweden University, 831 25 Oestersund (Sweden)

2009-02-15

In this study we examine the use of wood products as a means to mitigate climate change. We describe the life cycle of wood products including forest growth, wood harvest and processing, and product use and disposal, focusing on the multiple roles of wood as both material and fuel. We present a comparative case study of a building constructed with either a wood or a reinforced concrete frame. We find that the production of wood building material uses less energy and emits less carbon than the production of reinforced concrete material. We compare the relative cost of the two building methods without environmental taxation, under the current Swedish industrial energy taxation regime, and in scenarios that incorporate estimates of the full social cost of carbon emission. We find that the inclusion of climate-related external costs improves the economic standing of wood construction vis-a-vis concrete construction. We conclude that policy instruments that internalise the external costs of carbon emission should encourage a structural change toward the increased use of sustainably produced wood products. (author)

Productive osseous changes about the wrist in rheumatoid arthritis

International Nuclear Information System (INIS)

Cantor, R.M.; Braunstein, E.M.

1987-01-01

Radiographs of 225 consecutive patients with adult-form rheumatoid arthritis were examined for evidence of productive osseous changes about the wrist. The prevalence of new bone on the ulnar styloid was 10%. This form of new bone is probably due to overlying chronic tenosynovitis. A collar of new bone around the ulnar head is a result of degenerative change in the distal radioulnar joint. In general, productive osseous changes in theumatoid arthritis may represent inflammatory periosteal bone formation, osteophytosis, or contact remodeling. We found no evidence of an association between diffuse idiopathic skeletal hyperostosis and extensive productive osseous changes in patients with rheumatoid arthritis. (orig.)

Productive osseous changes about the wrist in rheumatoid arthritis

Energy Technology Data Exchange (ETDEWEB)

Cantor, R.M.; Braunstein, E.M.

1987-07-01

Radiographs of 225 consecutive patients with adult-form rheumatoid arthritis were examined for evidence of productive osseous changes about the wrist. The prevalence of new bone on the ulnar styloid was 10%. This form of new bone is probably due to overlying chronic tenosynovitis. A collar of new bone around the ulnar head is a result of degenerative change in the distal radioulnar joint. In general, productive osseous changes in theumatoid arthritis may represent inflammatory periosteal bone formation, osteophytosis, or contact remodeling. We found no evidence of an association between diffuse idiopathic skeletal hyperostosis and extensive productive osseous changes in patients with rheumatoid arthritis.

Alaska’s timber harvest and forest products industry, 2011

Science.gov (United States)

Erik C. Berg; Charles B. Gale; Todd A. Morgan; Allen M. Brackley; Charles E. Keegan; Susan J. Alexander; Glenn A. Christensen; Chelsea P. McIver; Micah G. Scudder

2014-01-01

This report traces the flow of timber harvested in Alaska during calendar year 2011, describes the composition and operations of the state’s primary forest products industry, and quantifies volumes and uses of wood fiber. Historical wood products industry changes are discussed, as well as trends in timber harvest, production, export, sales of primary wood products,...

Evaluation of MODIS gross primary productivity for Africa using eddy covariance data

NARCIS (Netherlands)

Sjostrom, M.; Zhao, M.; Archibald, S.; Veenendaal, E.M.

2013-01-01

MOD17A2 provides operational gross primary production (GPP) data globally at 1 km spatial resolution and 8-day temporal resolution. MOD17A2 estimates GPP according to the light use efficiency (LUE) concept assuming a fixed maximum rate of carbon assimilation per unit photosynthetically active

Recent changes in mercury deposition and primary productivity inferred from sediments of lakes from the Hudson Bay Lowlands, Ontario, Canada

International Nuclear Information System (INIS)

Brazeau, Michelle L.; Poulain, Alexandre J.; Paterson, Andrew M.; Keller, Wendel; Sanei, Hamed; Blais, Jules M.

2013-01-01

Spatial and temporal changes in mercury (Hg) concentrations and organic carbon in lake sediments were examined from the Hudson Bay Lowlands to investigate whether Hg deposition to sediments is related to indicators of autochthonous production. Total organic carbon, “S2” carbon (mainly algal-derived OC), C:N and ∂ 13 C indicators suggest an increase in autochthonous productivity in recent decades. Up-core profiles of S2 concentrations and fluxes were significantly correlated with Hg suggesting that varying algal matter scavenging of Hg from the water column may play an important role in the temporal profiles of Hg throughout the sediment cores. Absence of significant relationship between total Hg and methyl Hg (MeHg) in surficial sediments suggested that inorganic Hg supply does not limit MeHg production. MeHg and OC were highly correlated across lakes in surface and deep sediment layers, indicating that sediment organic matter content explains part of the spatial variation in MeHg concentrations between lakes. - Highlights: ► Hg concentrations in sediment cores correlate with autochthonous organic production. ► Inorganic Hg supply in sediment does not limit MeHg production. ► Sediment methylmercury concentration is highly correlated with organic C content. - Increased mercury concentrations in lake sediment cores coincide with evidence of increased autochthonous production in lakes of the Hudson Bay Lowlands, Canada.

MODIS/Terra Gross Primary Productivity 8-Day L4 Global 1km SIN Grid V055

Data.gov (United States)

National Aeronautics and Space Administration — The Terra/MODIS Gross Primary Productivity (GPP) product (MOD17A2) is a cumulative composite of GPP values based on the radiation-use efficiency concept that is...

A 10-day heatwave at flowering superimposed on climate change conditions strongly affects production of 22 barley accessions

DEFF Research Database (Denmark)

Ingvordsen, Cathrine Heinz; Lyngkjær, Michael F.; Peltonen-Sainio, Pirjo

Extreme climate events are projected to be among the future most challenging constraints to plant development. Heatwaves as well as floods and droughts cause acute changes in the growth environment determining our primary production (Collins et al., 2013). Europe experienced extreme heatwaves...... in 2003 and 2006. In 2003, a 21 % decrease in the French wheat production was found from temperatures up to 6 °C above long-term means and precipitation being less than 50 % of the average (Ciais et al., 2005). One strategy to mitigate the this decrease from heatwaves is to identify resilient cultivars...

Application of Primary Abatement Technology for Reduction of N2O Emmision in Petrokemija Nitric Acid Production

Directory of Open Access Journals (Sweden)

Ćosić, L.

2013-01-01

Full Text Available Industrial nitric acid production by oxidation of gaseous ammonia with Ostwald procedure produces an unwanted by-product – colorless nitrous oxide, N2O. As emission of N2O represents a very serious problem due of its huge contribution to global warming, certain measures focused on its maximum reduction should be undertaken. Minimization of N2O emission in nitric acid production can be achieved in different parts of the process flow, depending on the applied available technologies. For the abatement of N2O emissions in Petrokemija's nitric acid production processes from the list of the best available technologies chosen were primary and secondary abatement technologies. The mentioned ensures reduction of N2O by use of improved selective heterogeneous catalysts in the step of gaseous ammonia oxidation. Precious metals in the shape of gauzes are used as selective heterogeneous catalyst in primary technology, while in the case of secondary technology the Fe2 O3 catalyst on Al2O3 support in the shape of spherical pellets is chosen. Shown is the application of primary technology for the abatement of N2O in both nitric acid production facilities and their comparison with classical heterogeneous catalyst and preparation for the installation of secondary selective catalyst. N2O emissions with the application of primary technology in both production facilities were reduced from 12 kg of N2O to 7 kg of N2O per ton of pure HNO3. With the primary reduction in N2O emissions the foundation was established for further reduction with the secondary technology to the final value of 0.7 kg of N2O per ton of pure HNO3, which represents mass concentration in the tail gas below 200 mg m-3 (at n. c.. With the applied technologies for the abatement of N2O emissions in Petrokemija's nitric acid production the future prescribed emission limit value will be satisfied.

Impact of biodiversity-climate futures on primary production and metabolism in a model benthic estuarine system.

Science.gov (United States)

Hicks, Natalie; Bulling, Mark T; Solan, Martin; Raffaelli, Dave; White, Piran C L; Paterson, David M

2011-02-14

Understanding the effects of anthropogenically-driven changes in global temperature, atmospheric carbon dioxide and biodiversity on the functionality of marine ecosystems is crucial for predicting and managing the associated impacts. Coastal ecosystems are important sources of carbon (primary production) to shelf waters and play a vital role in global nutrient cycling. These systems are especially vulnerable to the effects of human activities and will be the first areas impacted by rising sea levels. Within these coastal ecosystems, microalgal assemblages (microphytobenthos: MPB) are vital for autochthonous carbon fixation. The level of in situ production by MPB mediates the net carbon cycling of transitional ecosystems between net heterotrophic or autotrophic metabolism. In this study, we examine the interactive effects of elevated atmospheric CO(2) concentrations (370, 600, and 1000 ppmv), temperature (6°C, 12°C, and 18°C) and invertebrate biodiversity on MPB biomass in experimental systems. We assembled communities of three common grazing invertebrates (Hydrobia ulvae, Corophium volutator and Hediste diversicolor) in monoculture and in all possible multispecies combinations. This experimental design specifically addresses interactions between the selected climate change variables and any ecological consequences caused by changes in species composition or richness. The effects of elevated CO(2) concentration, temperature and invertebrate diversity were not additive, rather they interacted to determine MPB biomass, and overall this effect was negative. Diversity effects were underpinned by strong species composition effects, illustrating the importance of individual species identity. Overall, our findings suggest that in natural systems, the complex interactions between changing environmental conditions and any associated changes in invertebrate assemblage structure are likely to reduce MPB biomass. Furthermore, these effects would be sufficient to affect the

Impact of biodiversity-climate futures on primary production and metabolism in a model benthic estuarine system

Directory of Open Access Journals (Sweden)

Raffaelli Dave

2011-02-01

Full Text Available Abstract Background Understanding the effects of anthropogenically-driven changes in global temperature, atmospheric carbon dioxide and biodiversity on the functionality of marine ecosystems is crucial for predicting and managing the associated impacts. Coastal ecosystems are important sources of carbon (primary production to shelf waters and play a vital role in global nutrient cycling. These systems are especially vulnerable to the effects of human activities and will be the first areas impacted by rising sea levels. Within these coastal ecosystems, microalgal assemblages (microphytobenthos: MPB are vital for autochthonous carbon fixation. The level of in situ production by MPB mediates the net carbon cycling of transitional ecosystems between net heterotrophic or autotrophic metabolism. In this study, we examine the interactive effects of elevated atmospheric CO2 concentrations (370, 600, and 1000 ppmv, temperature (6°C, 12°C, and 18°C and invertebrate biodiversity on MPB biomass in experimental systems. We assembled communities of three common grazing invertebrates (Hydrobia ulvae, Corophium volutator and Hediste diversicolor in monoculture and in all possible multispecies combinations. This experimental design specifically addresses interactions between the selected climate change variables and any ecological consequences caused by changes in species composition or richness. Results The effects of elevated CO2 concentration, temperature and invertebrate diversity were not additive, rather they interacted to determine MPB biomass, and overall this effect was negative. Diversity effects were underpinned by strong species composition effects, illustrating the importance of individual species identity. Conclusions Overall, our findings suggest that in natural systems, the complex interactions between changing environmental conditions and any associated changes in invertebrate assemblage structure are likely to reduce MPB biomass. Furthermore

Size-fractionated dissolved primary production and carbohydrate composition of the coccolithophore Emiliania huxleyi

Science.gov (United States)

Borchard, C.; Engel, A.

2015-02-01

Extracellular release (ER) by phytoplankton is the major source of fresh dissolved organic carbon (DOC) in marine ecosystems and accompanies primary production during all growth phases. Little is known, so far, on size and composition of released molecules, and to which extent ER occurs passively, by leakage, or actively, by exudation. Here, we report on ER by the widespread and bloom-forming coccolithophore Emiliania huxleyi grown under steady-state conditions in phosphorus-controlled chemostats (N:P = 29, growth rate of μ = 0.2 d-1) at present-day and high-CO2 concentrations. 14C incubations were performed to determine primary production (PP), comprised of particulate (PO14C) and dissolved organic carbon (DO14C). Concentration and composition of particulate combined carbohydrates (pCCHO) and high-molecular-weight (>1 kDa, HMW) dissolved combined carbohydrates (dCCHO) were determined by ion chromatography. Information on size distribution of ER products was obtained by investigating distinct size classes (10 kDa was significantly different, with a higher mol% of arabinose. The mol% of acidic sugars increased and that of glucose decreased with increasing size of HMW-dCCHO. We conclude that larger polysaccharides follow different production and release pathways than smaller molecules, potentially serving distinct ecological and biogeochemical functions.

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

Directory of Open Access Journals (Sweden)

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.

The Impact of Variable Phytoplankton Stoichiometry on Projections of Primary Production, Food Quality, and Carbon Uptake in the Global Ocean

Science.gov (United States)

Kwiatkowski, Lester; Aumont, Olivier; Bopp, Laurent; Ciais, Philippe

2018-04-01

Ocean biogeochemical models are integral components of Earth system models used to project the evolution of the ocean carbon sink, as well as potential changes in the physical and chemical environment of marine ecosystems. In such models the stoichiometry of phytoplankton C:N:P is typically fixed at the Redfield ratio. The observed stoichiometry of phytoplankton, however, has been shown to considerably vary from Redfield values due to plasticity in the expression of phytoplankton cell structures with different elemental compositions. The intrinsic structure of fixed C:N:P models therefore has the potential to bias projections of the marine response to climate change. We assess the importance of variable stoichiometry on 21st century projections of net primary production, food quality, and ocean carbon uptake using the recently developed Pelagic Interactions Scheme for Carbon and Ecosystem Studies Quota (PISCES-QUOTA) ocean biogeochemistry model. The model simulates variable phytoplankton C:N:P stoichiometry and was run under historical and business-as-usual scenario forcing from 1850 to 2100. PISCES-QUOTA projects similar 21st century global net primary production decline (7.7%) to current generation fixed stoichiometry models. Global phytoplankton N and P content or food quality is projected to decline by 1.2% and 6.4% over the 21st century, respectively. The largest reductions in food quality are in the oligotrophic subtropical gyres and Arctic Ocean where declines by the end of the century can exceed 20%. Using the change in the carbon export efficiency in PISCES-QUOTA, we estimate that fixed stoichiometry models may be underestimating 21st century cumulative ocean carbon uptake by 0.5-3.5% (2.0-15.1 PgC).

Thermodynamics and the transport of corrosion products in PWR primary circuits

International Nuclear Information System (INIS)

Turner, D.J.

1992-01-01

It is argued that practically useful models for the activation, transport and deposition of corrosion products in PWR primary circuits can only be produced on the basis of an improved understanding of the chemical processes which control them. In particular, if a model is to make reliable predictions it is essential that its thermodynamic basis be sound. This is not the case with most current models which employ the erroneous concept of a corrosion product 'solubility'. In addition to the misuse of this term, other complications are discussed. These include the need to take account of the consequences of Gibbs' phase rule and the fact that, for mixed spinels, neither the concept of a thermodynamic solubility nor of a solubility product is valid. There is no reason to believe that measured apparent solubilities of nickel ferrites or spinel mixtures containing cobalt can give any direct guidance on the direction of transport of Ni or Co in PWR primary circuits. This is more likely to be determined by the distribution of stable and unstable ferrites and chromites than by any temperature coefficient of apparent solubility. Most of the transport of Ni and Co into and out of the core probably occurs as a consequence of either chemical or mechanical transients. Most important is likely to be the oxidative destruction and subsequent re-precipitation of chromites which occurs as a consequence of the oxygenated conditions employed during plant shutdown. (author)

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

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.

The Impact of Product Price Changes on the Turnover of Small and Medium Enterprises in Nigeria

Directory of Open Access Journals (Sweden)

Imoleayo Foyeke Obigbemi

2010-05-01

Full Text Available Pricing decision has been a crucial decision made by all business enterprises at all levels and has posed a great challenge for Small and Medium Enterprises in Nigeria. This research work treats the impact of change in price on the sales turnover of organizations, a study of SMEs in Nigeria. The methodology adopted was the survey and empirical approach, with the administration of questionnaires to some SMEs in Nigeria, evaluating the effect change in product price has on turnover. Primary and secondary sources were used to in collecting data. It was discovered that there is a relationship between change in cost of sales and turnover. Recommendations were made for the close monitoring of SMEs and that SMEs should employ the service of price experts when making pricing decisions.

Estimates of primary productivity over the Thar Desert based upon Nimbus-7 37 GHz data - 1979-1985

Science.gov (United States)

Choudhury, B. J.

1987-01-01

An empirical relationship has been determined between the difference of vertically and horizontally polarized brightness temperatures noted at the 37 GHz frequency of the Nimbus-7 SMMR and primary productivity over hot arid and semiarid regions of Africa and Australia. This empirical relationship is applied to estimate the primary productivity over the Thar Desert between 1979 and 1985, giving an average value of 0.271 kg/sq m per yr. The spatial variability of the productivity values is found to be quite significant, with a standard deviation about the mean of 0.08 kg/sq m per yr.

Warming Increases the Proportion of Primary Production Emitted as Methane from Freshwater Mesocosms

OpenAIRE

2010-01-01

Abstract Methane and carbon dioxide are the dominant gaseous end products of the remineralisation of organic carbon and also the two largest contributors to the anthropogenic greenhouse effect. We investigated whether warming altered the balance of methane efflux relative to primary production and ecosystem respiration in a freshwater mesocosm experiment. Whole ecosystem CH4 efflux was strongly related to temperature with an apparent activation energy of 0.85eV. Furthermore, CH4 ef...

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.

Safety assessment of smoke flavouring primary products by the European Food Safety Authority

NARCIS (Netherlands)

Theobald, A.; Arcella, D.; Carere, A.; Croera, C.; Engel, K.H.; Gott, D.; Gurtler, R.; Meier, D.; Pratt, I.; Rietjens, I.M.C.M.; Simon, R.; Walker, R.

2012-01-01

This paper summarises the safety assessments of eleven smoke flavouring primary products evaluated by the European Food Safety Authority (EFSA). Data on chemical composition, content of polyaromatic hydrocarbons and results of genotoxicity tests and subchronic toxicity studies are presented and

Modelling contrasting responses of wetland productivity to changes in water table depth

Directory of Open Access Journals (Sweden)

R. F. Grant

2012-11-01

Full Text Available Responses of wetland productivity to changes in water table depth (WTD are controlled by complex interactions among several soil and plant processes, and hence are site-specific rather than general in nature. Hydrological controls on wetland productivity were studied by representing these interactions in connected hummock and hollow sites in the ecosystem model ecosys, and by testing CO₂ and energy fluxes from the model with those measured by eddy covariance (EC during years with contrasting WTD in a shrub fen at Lost Creek, WI. Modelled interactions among coupled processes for O₂ transfer, O₂ uptake, C oxidation, N mineralization, N uptake and C fixation by diverse microbial, root and mycorrhizal populations enabled the model to simulate complex responses of CO₂ exchange to changes in WTD that depended on the WTD at which change was occurring. At the site scale, greater WTD caused the model to simulate greater CO₂ influxes and effluxes over hummocks vs. hollows, as has been found at field sites. At the landscape scale, greater WTD caused the model to simulate greater diurnal CO₂ influxes and effluxes under cooler weather when water tables were shallow, but also smaller diurnal CO₂ influxes and effluxes under warmer weather when water tables were deeper, as was also apparent in the EC flux measurements. At an annual time scale, these diurnal responses to WTD in the model caused lower net primary productivity (NPP and heterotrophic respiration (R_h, but higher net ecosystem productivity (NEP = NPP − R_h, to be simulated in a cooler year with a shallower water table than in a warmer year with a deeper one. This difference in NEP was consistent with those estimated from gap-filled EC fluxes in years with different water tables at Lost Creek and at similar boreal fens elsewhere. In sensitivity tests of the model, annual NEP

Primary productivity and the prospects for biofuels in the United Kingdom

Science.gov (United States)

Lawson, G. J.; Callaghan, T. V.

1983-09-01

Estimates of land use and plant productivity are combined to predict total annual primary production in the UK as 252 million tonnes dry matter (10.5 t ha-1yr-1). Annual above ground production is predicted to be 165 Mt (6.9 t ha-1yr-1). Within these totals, intensive agriculture contributes 60%, productive woodland 8%, natural vegetation 26% and urban vegetation 5%. However, only 25% of total plant production is cropped by man and animals, and most of this is subsequently discarded as wastes and residues. 2112 PJ of organic material is available for fuel without reducing food or fibre production, but since much of this could not be economically collected, 859 PJ is calculated as a more realistic biofuel contribution by the year 2000. After deducting 50% conversion losses, this could save P1 billion (1979 prices) in oil imports. Short rotation energy plantations, forest residues, coppice woodlands, animal and crop wastes, industrial and domestic wastes, catch crops, natural vegetation and urban vegetation all have immediate or short term potential as biofuel sources. Sensitive planning is required to reduce environmental impact, but in some cases more diverse wildlife habitats may be created.

Biophysical drivers of seasonal variability in Sphagnum gross primary production in a northern temperate bog

Science.gov (United States)

Walker, Anthony P.; Carter, Kelsey R.; Gu, Lianhong; Hanson, Paul J.; Malhotra, Avni; Norby, Richard J.; Sebestyen, Stephen D.; Wullschleger, Stan D.; Weston, David J.

2017-05-01

Sphagnum mosses are the keystone species of peatland ecosystems. With rapid rates of climate change occurring in high latitudes, vast reservoirs of carbon accumulated over millennia in peatland ecosystems are potentially vulnerable to rising temperature and changing precipitation. We investigate the seasonal drivers of Sphagnum gross primary production (GPP)—the entry point of carbon into wetland ecosystems. Continuous flux measurements and flux partitioning show a seasonal cycle of Sphagnum GPP that peaked in the late summer, well after the peak in photosynthetically active radiation. Wavelet analysis showed that water table height was the key driver of weekly variation in Sphagnum GPP in the early summer and that temperature was the primary driver of GPP in the late summer and autumn. Flux partitioning and a process-based model of Sphagnum photosynthesis demonstrated the likelihood of seasonally dynamic maximum rates of photosynthesis and a logistic relationship between the water table and photosynthesizing tissue area when the water table was at the Sphagnum surface. The model also suggested that variability in internal resistance to CO2 transport, a function of Sphagnum water content, had minimal effect on GPP. To accurately model Sphagnum GPP, we recommend the following: (1) understanding seasonal photosynthetic trait variation and its triggers in Sphagnum; (2) characterizing the interaction of Sphagnum photosynthesizing tissue area with water table height; (3) modeling Sphagnum as a "soil" layer for consistent simulation of water dynamics; and (4) measurement of Sphagnum "canopy" properties: extinction coefficient (k), clumping (Ω), and maximum stem area index (SAI).

Climate Change: Seed Production and Options for Adaptation

Directory of Open Access Journals (Sweden)

John G. Hampton

2016-07-01

Full Text Available Food security depends on seed security and the international seed industry must be able to continue to deliver the quantities of quality seed required for this purpose. Abiotic stress resulting from climate change, particularly elevated temperature and water stress, will reduce seed yield and quality. Options for the seed industry to adapt to climate change include moving sites for seed production, changing sowing date, and the development of cultivars with traits which allow them to adapt to climate change conditions. However, the ability of seed growers to make these changes is directly linked to the seed system. In the formal seed system operating in developed countries, implementation will be reasonably straight forward. In the informal system operating in developing countries, the current seed production challenges including supply failing to meet demand and poor seed quality will increase with changing climates.

Microphytobenthic primary production along a non-tidal sandy beach gradient: an annual study from the Baltic Sea

Directory of Open Access Journals (Sweden)

Barbara Urban-Malinga

2003-12-01

Full Text Available The microphytobenthic primary production and chlorophyll a content were studied over the annual cycle (May 1998 - May 1999 on a non-tidal Baltic sandy beach at three stations along the beach gradient: littoral, waterline and splash zone. The chlorophyll a concentrations varied between 0.88 and 12.18 µg cm-3. Net and gross primary production rates respectively lay within the ranges 0.1-31.4 mgC m-2 h-1 and 0.2-41.8 mgC m-2 h-1. The highest values of both Chl a content and primary production were noted at the littoral station, the lowest ones at the waterline. The mean annual P/B ratio was highest at the waterline. The differences in Chl a content between stations were statistically significant and may be related to water dynamics, resuspension and water content. Production rates were highly variable on monthly time scales, and the highest results at all the study locations were noted in July. The gross photosynthetic rates were significantly correlated with water temperature.

Absorption-based algorithm of primary production for total and size-fractionated phytoplankton in coastal waters

NARCIS (Netherlands)

Barnes, M.K.; Tilstone, G.H.; Smyth, T.J.; Suggett, D.J.; Astoreca, R.; Lancelot, C.; Kromkamp, J.C.

2014-01-01

Most satellite models of production have been designed and calibrated for use in the open ocean. Coastal waters are optically more complex, and the use of chlorophyll a (chl a) as a first-order predictor of primary production may lead to substantial errors due to significant quantities

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.

Changes in primary health care centres over the transition period in Slovenia.

NARCIS (Netherlands)

Albreht, T.; Delnoij, D.M.J.; Klazinga, N.

2006-01-01

BACKGROUND: Primary health care centres (PHCCs) were a characteristic of the former Yugoslav health care system introduced widely in Slovenia. Transition brought structural changes to health care and the position of the PHCC's was challenged. This paper investigates (i) PHCCs' perception of

Changes in primary health care centres over the transition period in Slovenia

NARCIS (Netherlands)

Albreht, Tit; Delnoij, Diana M. J.; Klazinga, Niek

2006-01-01

BACKGROUND: Primary health care centres (PHCCs) were a characteristic of the former Yugoslav health care system introduced widely in Slovenia. Transition brought structural changes to health care and the position of the PHCC's was challenged. This paper investigates (i) PHCCs' perception of

Predictive factors of user acceptance on the primary educational mathematics aids product

Science.gov (United States)

Hidayah, I.; Margunani; Dwijanto

2018-03-01

Mathematics learning in primary schools requires instructional media. According to Piaget's theory, students are still in the concrete operational stage. For this reason, the development of the primary level mathematics aids is needed to support the development of successful mathematics learning. The stages of this research are the stages of commercialization with preparatory, marketing, and measurement analysis procedures. Promotion as part of marketing is done by doing a demonstration to the teacher. Measurements were performed to explore the predictive factors of user feasibility in adopting the product. Measurements were conducted using the concept of Technology Acceptance Model (TAM). Measurement variables include external variables, perceived usefulness, perceived ease of use, attitude, intention to use, and actual use. The result of this research shows that the contribution of predictive factors of mathematics teachers on the teaching aids product as follows: the external variable and perceived ease of use at 74%, perceived usefulness at 72%, intention to use (behavioral) at 58%, attitude at 52%, and the consequence factor (actual use) at 42%.

NODC Standard Format Primary Productivity 1 (F029) Data (1958-1983) (NODC Accession 0014152)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains data from measurements of primary productivity. The data are collected to provide information on nutrient levels and nutrient flow in offshore...

Cultivated Land Changes and Agricultural Potential Productivity in Mainland China

Directory of Open Access Journals (Sweden)

Linlin Xiao

2015-08-01

Full Text Available With rapid and continuous population growth and the associated declining quality of cultivated land, food security in China has been attracting the attention of scholars both domestically and internationally. In recent decades, the implications of the cultivated land balance policy have promoted spatial changes of cultivated land. Estimating the agricultural potential productivity and assessing its response to cultivated land changes could provide a scientific basis for strategic decision-making concerning grain production and thus guarantee food security. In the present study, the Agro-Ecological Zone (AEZ model was applied to estimate the agricultural potential productivity. Data from the second national land survey were first applied to characterize the changes of cultivated land (by comparing the cultivated land in 2009 with that in 2012 and their influence on potential productivity in Mainland China. We propose a utilization degree of total potential productivity (UTP and its ratio coefficient (RUTP to reveal the utilization status of potential productivity and its change characteristics at the provincial level. It was found that there was a trend for cultivated land to be shifted away from cities, and the average productive capability per hectare of cultivated land declined from 7386.5 kg/ha to 6955.2 kg/ha by occupying highly productive cultivated land generally near the cities and compensating less productive cultivated land in remote areas. UTPs and RUTPs indicate a significant difference in the utilization status of potential productivity among the 31 provinces of Mainland China. Grain production with the aim of sustainable development should be strategized according to the particular facts of each province. The methods we applied can mine the impacts of cultivated land changes on potential productivity and the utilization of potential productivity effectively.

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

Landscape level influence: aquatic primary production in the Colorado River of Glen and Grand canyons

Science.gov (United States)

Yard, M. D.; Kennedy, T.; Yackulic, C. B.; Bennett, G. E.

2012-12-01

Irregular features common to canyon-bound regions intercept solar incidence (photosynthetic photon flux density [PPFD: μmol m-2 s-1]) and can affect ecosystem energetics. The Colorado River in Grand Canyon is topographically complex, typical of most streams and rivers in the arid southwest. Dam-regulated systems like the Colorado River have reduced sediment loads, and consequently increased water transparency relative to unimpounded rivers; however, sediment supply from tributaries and flow regulation that affects erosion and subsequent sediment transport, interact to create spatial and temporal variation in optical conditions in this river network. Solar incidence and suspended sediment loads regulate the amount of underwater light available for aquatic photosynthesis in this regulated river. Since light availability is depth dependent (Beer's law), benthic algae is often exposed to varying levels of desiccation or reduced light conditions due to daily flow regulation, additional factors that further constrain aquatic primary production. Considerable evidence suggests that the Colorado River food web is now energetically dependent on autotrophic production, an unusual condition since large river foodwebs are typically supported by allochthonous carbon synthesized and transported from terrestrial environments. We developed a mechanistic model to account for these regulating factors to predict how primary production might be affected by observed and alternative flow regimes proposed as part of ongoing adaptive management experimentation. Inputs to our model include empirical data (suspended sediment and temperature), and predictive relationships: 1) solar incidence reaching the water surface (topographic complexity), 2) suspended sediment-light extinction relationships (optical properties), 3) unsteady flow routing model (stage-depth relationship), 4) channel morphology (photosynthetic area), and 5) photosynthetic-irradiant response for dominant algae (Cladophora

Assessment of postoperative changes in antihypertensive drug consumption in patients with primary aldosteronism using the defined daily dose

Directory of Open Access Journals (Sweden)

Takanobu Utsumi

2014-10-01

Conclusion: The defined daily dose is a useful tool for assessing total changes in the consumption of antihypertensive drugs in patients with primary aldosteronism. Using the defined daily dose, clinicians could explain in detail to patients with primary aldosteronism the predicted postoperative change in antihypertensive drug consumption.

Development of experimental method to simulate the corrosion products in the primary system of nuclear power plant

International Nuclear Information System (INIS)

Kim, Sang Hyun; Kim, In Sup; Jang, Chang Heui

2005-01-01

Corrosion products are recognized as one of the major sources of occupational radiation exposure for nuclear power plant workers. Numerous studies have been conducted on the primary water chemistry to reduce the amount of crud in the primary circuit to avoid the radioactivity build-up in the plant. However, experiments with crud are restricted in laboratory because the crud is highly radioactive material. The objective of this study is to develop the simulating method of corrosion product in nuclear power plant

SeaWiFS Technical Report Series. Volume 42; Satellite Primary Productivity Data and Algorithm Development: A Science Plan for Mission to Planet Earth

Science.gov (United States)

Falkowski, Paul G.; Behrenfeld, Michael J.; Esaias, Wayne E.; Balch, William; Campbell, Janet W.; Iverson, Richard L.; Kiefer, Dale A.; Morel, Andre; Yoder, James A.; Hooker, Stanford B. (Editor);

The Puzzle of HCN in Comets: Is it both a Product and a Primary Species?

Science.gov (United States)

Mumma, Michael J.; Bonev, Boncho P.; Charnley, Steven B.; Cordiner, Martin A.; DiSanti, Michael A.; Gibb, Erika L.; Magee-Sauer, Karen; Paganini, Lucas; Villanueva, Geronimo L.

2014-11-01

Hydrogen cyanide has long been regarded as a primary volatile in comets, stemming from its presence in dense molecular cloud cores and its supposed storage in the cometary nucleus. Here, we examine the observational evidence for and against that hypothesis, and argue that HCN may also result from near-nucleus chemical reactions in the coma. The distinction (product vs. primary species) is important for multiple reasons: 1. HCN is often used as a proxy for water when the dominant species (H2O) is not available for simultaneous measurement, as at radio wavelengths. 2. HCN is one of the few volatile carriers of nitrogen accessible to remote sensing. If HCN is mainly a product species, its precursor becomes the more important metric for compiling a taxonomic classification based on nitrogen chemistry. 3. The stereoisomer HNC is now confirmed as a product species. Could reaction of a primary precursor (X-CN) with a hydrocarbon co-produce both HNC and HCN? 4. The production rate for CN greatly exceeds that of HCN in some comets, demonstrating the presence of another (more important) precursor of CN. Several puzzling lines of evidence raise issues about the origin of HCN: a. The production rates of HCN measured through rotational (radio) and vibrational (infrared) spectroscopy agree in some comets - in others the infrared rate exceeds the radio rate substantially. b. With its strong dipole moment and H-bonding character, HCN should be linked more strongly in the nuclear ice to other molecules with similar properties (H2O, CH3OH), but instead its spatial release in some comets seems strongly coupled to volatiles that lack a dipole moment and thus do not form H-bonds (methane, ethane). c. The nucleus-centered rotational temperatures measured for H2O and other species (C2H6, CH3OH) usually agree within error, but those for HCN are often slightly smaller. d. In comet ISON, ALMA maps of HCN and the dust continuum show a slight displacement 80 km) in the centroids. We will

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.

Regulatory assessment of brand changes in the commercial tobacco product market.

Science.gov (United States)

Wayne, G Ferris; Connolly, G N

2009-08-01

Regulatory oversight of tobacco product design has gained momentum in the US and internationally. Appropriate standards for assessing commercial brands and characterising product features must be considered a priority. An area of potential concern is in-market design changes adopted within a single commercial brand over time. Internal tobacco industry documents were identified and used to assess internal discussion of product guidelines and practices regarding in-market brand changes. Commercial tobacco products undergo a constant process of revision in-market, beginning at the most basic level of physical product characteristics and components, and including every aspect of design. These revisions commonly exceed guidelines for acceptable product variance adopted within the industry. While consumer and market testing is conducted to ensure that products remain acceptable to users, explicit marketing often may not accompany brand changes. In the absence of such marketing, it should not be assumed that a brand remains unchanged. For manufacturers, assessment of competitor brands includes identification and analysis of non-routine changes; that is, those changes likely to significantly alter the character of a given brand. Regulators must adopt a similar practice in determining standards for product evaluation in the face of ongoing commercial product revision.

Simulated Vegetation Response to Climate Change in California: The Importance of Seasonal Production Patterns

Science.gov (United States)

Kim, J. B.; Pitts, B.

2013-12-01

summarized MC1 outputs under the four climate change projections also by computing statistics by EPA Level 3 Ecoregions. MC1 predicts the greatest shift of vegetation types for the drier biomes of California, including the Sonoran Desert and the Eastern Cascade Slopes and Foothills. Strong shifts are predicted for forest biomes, including the Sierra Nevada (42-74%), and the Coast Range (24-40%). The simulated shifts in vegetation types are mediated by simultaneous changes in live vegetation carbon, which in turn are driven by simulated net primary production (NPP) at a monthly time step. MC1's poor skill in reproducing seasonal variations of NPP when compared to MODIS monthly GPP values suggests that the resulting vegetation type shifts are likely inaccurately predicted by MC1. Improving MC1's algorithm for NPP to more closely track seasonal variations in MODIS GPP should result in more reliable predictions of vegetation response to climate change.

The effectiveness of motivational interviewing for health behaviour change in primary care settings: a systematic review.

Science.gov (United States)

Morton, Katie; Beauchamp, Mark; Prothero, Anna; Joyce, Lauren; Saunders, Laura; Spencer-Bowdage, Sarah; Dancy, Bernadette; Pedlar, Charles

2015-01-01

Motivational interviewing (MI) is a patient-centred approach to behaviour change that was originally developed in the addiction field but has increasingly been applied to public health settings with a focus on health promotion. The purpose of this review was to examine the evidence base for MI interventions in primary care settings with non-clinical populations to achieve behaviour change for physical activity, dietary behaviours and/or alcohol intake. We also sought to explore the specific behaviour change techniques included in MI interventions within primary care. Electronic databases were searched for relevant articles and 33 papers met inclusion criteria and were included. Approximately 50% of the included studies (n = 18) demonstrated positive effects in relation to health behaviour change. The efficacy of MI approaches is unclear given the inconsistency of MI descriptions and intervention components. Furthermore, research designs that do not isolate the effects of MI make it difficult to determine the effectiveness of such approaches. We offer a number of recommendations for researchers and practitioners seeking to include MI within behaviour change interventions to help improve the quality of the research and the effectiveness of MI-based interventions within primary care settings.

Suppressed hepatic bile acid signalling despite elevated production of primary and secondary bile acids in NAFLD.

Science.gov (United States)

Jiao, Na; Baker, Susan S; Chapa-Rodriguez, Adrian; Liu, Wensheng; Nugent, Colleen A; Tsompana, Maria; Mastrandrea, Lucy; Buck, Michael J; Baker, Robert D; Genco, Robert J; Zhu, Ruixin; Zhu, Lixin

2017-08-03

Bile acids are regulators of lipid and glucose metabolism, and modulate inflammation in the liver and other tissues. Primary bile acids such as cholic acid and chenodeoxycholic acid (CDCA) are produced in the liver, and converted into secondary bile acids such as deoxycholic acid (DCA) and lithocholic acid by gut microbiota. Here we investigated the possible roles of bile acids in non-alcoholic fatty liver disease (NAFLD) pathogenesis and the impact of the gut microbiome on bile acid signalling in NAFLD. Serum bile acid levels and fibroblast growth factor 19 (FGF19), liver gene expression profiles and gut microbiome compositions were determined in patients with NAFLD, high-fat diet-fed rats and their controls. Serum concentrations of primary and secondary bile acids were increased in patients with NAFLD. In per cent, the farnesoid X receptor (FXR) antagonistic DCA was increased, while the agonistic CDCA was decreased in NAFLD. Increased mRNA expression for cytochrome P450 7A1, Na + -taurocholate cotransporting polypeptide and paraoxonase 1, no change in mRNA expression for small heterodimer partner and bile salt export pump, and reduced serum FGF19 were evidence of impaired FXR and fibroblast growth factor receptor 4 (FGFR4)-mediated signalling in NAFLD. Taurine and glycine metabolising bacteria were increased in the gut of patients with NAFLD, reflecting increased secondary bile acid production. Similar changes in liver gene expression and the gut microbiome were observed in high-fat diet-fed rats. The serum bile acid profile, the hepatic gene expression pattern and the gut microbiome composition consistently support an elevated bile acid production in NAFLD. The increased proportion of FXR antagonistic bile acid explains, at least in part, the suppression of hepatic FXR-mediated and FGFR4-mediated signalling. Our study suggests that future NAFLD intervention may target the components of FXR signalling, including the bile acid converting gut microbiome. © Article

75 FR 166 - Postal Product Price Changes

Science.gov (United States)

2010-01-04

... POSTAL REGULATORY COMMISSION [Docket No. CP2009-49; Order No. 371] Postal Product Price Changes...-filed Postal Service request to change prices for a Global Plus 2 contract. This notice provides an...: On December 21, 2009, the Postal Service filed a notice that prices for the Global Plus 2 contract at...

Chemical aspects of fission product transport in the primary circuit of a light water reactor

International Nuclear Information System (INIS)

Bowsher, B.R.; Dickinson, S.; Nichols, A.L.; Ogden, J.S.; Potter, P.E.

1985-01-01

The transport and fission products in the primary circuit of a light water reactor are of fundamental importance in assessing the consequences of severe accidents. Recent experimental studies have concentrated upon the behaviour of simulant fission product species such as caesium iodide, caesium hydroxide and tellurium, in terms of their vapour deposition characteristics onto metals representative of primary circuit materials. An induction furnace has been used to generate high-density/structural materials aerosols for subsequent analysis, and similar equipment has been incorporated into a glove-box to study lightly-irradiated UO/sub 2/ clad in Zircaloy. Analytical techniques are being developed to assist in the identification of fission product chemical species released from the fuel at temperatures from 1000 to 2500 0 C. Matrix isolation-infrared spectroscopy has been used to identify species in the vapour phase, and specific data using this technique are reported

Chemical aspects of fission product transport in the primary circuit of a light water reactor

International Nuclear Information System (INIS)

Bowsher, B.R.; Dickinson, S.; Nichols, A.L.; Ogden, J.S.; Potter, P.E.

1985-01-01

The transport and deposition of fission products in the primary circuit of a light water reactor are of fundamental importance in assessing the consequences of severe accidents. Recent experimental studies have concentrated upon the behavior of simulant fission product species such as cesium iodide, cesium hydroxide and tellurium, in terms of their vapor deposition characteristics onto metals representative of primary circuit materials. An induction furnace has been used to generate high density/structural materials aerosols for subsequent analysis, and similar equipment has been incorporated into a glove-box to study lightly-irradiated UO 2 clad in Zircaloy. Analytical techniques are being developed to assist in the identification of fission product chemical species released from the fuel at temperatures from 1000 to 2500 0 C. Matrix isolation-infrared spectroscopy has been used to identify species in the vapor phase, and specific data using this technique are reported

Development of a nuclear spallation simulation code and calculations of primary spallation products

International Nuclear Information System (INIS)

Nishida, Takahiko; Nakahara, Yasuaki; Tsutsui, Tsuneo

1986-08-01

In order to make evaluations of computational models for the nuclear spallation reaction from a nuclear physics point of view, a simulation code NUCLEUS has been developed by modifying and combining the Monte Carlo codes NMTC/JAERI and NMTA/JAERI for calculating only the nuclear spallation reaction (intranuclear cascade + evaporation and/or fast fission) between a nucleus and a projectile without taking into consideration of internuclear transport. New several plotting routines have been provided for the rapid process of much more event data, obtained by using the ARGUS plotting system. The results obtained by our code can be directly compared with the experimental results using by thin foil experiments in which internuclear multiple collisions have little effects, and will serve to upgrade the calculational methods and the values of nuclear parameters currently used in the calculations. Some discussions are done about the preliminary computational results obtained by using NUCLEUS. The mass distribution and charge dispersion of reaction products are examined in some detail for the nuclear spallation reaction between incident protons and target nuclei, such as U, Pb and Ag, in the energy range from 0.5 GeV to 3.0 GeV. These results show that the distribution of reaction products ceases to change its form as the proton energy increases over about 2 GeV. The same tendency is seen in the energy dependence of the number of primary particles emitted from a nucleus. After spallation reactions, a variety of nuclei, especially many neutron deficient nuclides with nuclear charges nearly equal to ones of a target nucleus, are produced. Due to their short lifetime most of them will change to stable nuclides in due time. Finally, some important issues are discussed to improve the present simulation method. (author)

Satellite remote sensing for estimating leaf area index, FPAR and primary production. A literature review

International Nuclear Information System (INIS)

Boresjoe Bronge, Laine

2004-03-01

Land vegetation is a critical component of several biogeochemical cycles that have become the focus of concerted international research effort. Most ecosystem productivity models, carbon budget models, and global models of climate, hydrology and biogeochemistry require vegetation parameters to calculate land surface photosynthesis, evapotranspiration and net primary production. Therefore, accurate estimates of vegetation parameters are increasingly important in the carbon cycle, the energy balance and in environmental impact assessment studies. The possibility of quantitatively estimating vegetation parameters of importance in this context using satellite data has been explored by numerous papers dealing with the subject. This report gives a summary of the present status and applicability of satellite remote sensing for estimating vegetation productivity by using vegetation index for calculating leaf area index (LAI) and fraction of absorbed photosynthetically active radiation (FPAR). Some possible approaches for use of satellite data for estimating LAI, FPAR and net primary production (NPP) on a local scale are suggested. Recommendations for continued work in the Forsmark and Oskarshamn investigation areas, where vegetation data and NDVI-images based on satellite data have been produced, are also given

Satellite remote sensing for estimating leaf area index, FPAR and primary production. A literature review

Energy Technology Data Exchange (ETDEWEB)

Boresjoe Bronge, Laine [SwedPower AB, Stockholm (Sweden)

2004-03-01

Land vegetation is a critical component of several biogeochemical cycles that have become the focus of concerted international research effort. Most ecosystem productivity models, carbon budget models, and global models of climate, hydrology and biogeochemistry require vegetation parameters to calculate land surface photosynthesis, evapotranspiration and net primary production. Therefore, accurate estimates of vegetation parameters are increasingly important in the carbon cycle, the energy balance and in environmental impact assessment studies. The possibility of quantitatively estimating vegetation parameters of importance in this context using satellite data has been explored by numerous papers dealing with the subject. This report gives a summary of the present status and applicability of satellite remote sensing for estimating vegetation productivity by using vegetation index for calculating leaf area index (LAI) and fraction of absorbed photosynthetically active radiation (FPAR). Some possible approaches for use of satellite data for estimating LAI, FPAR and net primary production (NPP) on a local scale are suggested. Recommendations for continued work in the Forsmark and Oskarshamn investigation areas, where vegetation data and NDVI-images based on satellite data have been produced, are also given.

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.

Hydrogen Production Costs of Various Primary Energy Sources

International Nuclear Information System (INIS)

Choi, Jae Hyuk; Tak, Nam Il; Kim, Yong Hee; Park, Won Seok

2005-01-01

The limited resource and environmental impacts of fossil fuels are becoming more and more serious problems in the world. Consequently, hydrogen is in the limelight as a future alternative energy due to its clean combustion and inexhaustibility and a transition from the traditional fossil fuel system to a hydrogen-based energy system is under considerations. Several countries are already gearing the industries to the hydrogen economy to cope with the limitations of the current fossil fuels. Unfortunately, hydrogen has to be chemically separated from the hydrogen compounds in nature such as water by using some energy sources. In this paper, the hydrogen production costs of major primary energy sources are compared in consideration of the Korean situations. The evaluation methodology is based on the report of the National Academy of Science (NAS) of U.S

PRIMARY PRODUCTION OF SEAGRASS BEDS IN SOUTH SULAWESI (INDONESIA) - A COMPARISON OF HABITATS, METHODS AND SPECIES

NARCIS (Netherlands)

ERFTEMEIJER, PLA; OSINGA, R; MARS, AE

Primary production of tropical seagrass meadows was studied between April and August 1990 in South Sulawesi, Indonesia. Oxygen evolution studies in enclosures over seagrass vegetation revealed gross community production values between 900 and 4400 mg C m-2 day-1. Assumed community respiration ranged

Data on gene and protein expression changes induced by apabetalone (RVX-208 in ex vivo treated human whole blood and primary hepatocytes

Directory of Open Access Journals (Sweden)

Sylwia Wasiak

2016-09-01

Full Text Available Apabetalone (RVX-208 inhibits the interaction between epigenetic regulators known as bromodomain and extraterminal (BET proteins and acetyl-lysine marks on histone tails. Data presented here supports the manuscript published in Atherosclerosis “RVX-208, a BET-inhibitor for Treating Atherosclerotic Cardiovascular Disease, Raises ApoA-I/HDL and Represses Pathways that Contribute to Cardiovascular Disease” (Gilham et al., 2016 [1]. It shows that RVX-208 and a comparator BET inhibitor (BETi JQ1 increase mRNA expression and production of apolipoprotein A-I (ApoA-I, the main protein component of high density lipoproteins, in primary human and African green monkey hepatocytes. In addition, reported here are gene expression changes from a microarray-based analysis of human whole blood and of primary human hepatocytes treated with RVX-208. Keywords: Bromodomain, BET proteins, BET inhibitor, RVX-208, JQ1, Vascular inflammation, ApoA-I, Apolipoprotein A-I, African green monkey, Primary human hepatocytes, Gene expression, Microarrays

Chlorophyll induced fluorescence retrieved from GOME2 for improving gross primary productivity estimates of vegetation

Science.gov (United States)

van Leth, Thomas C.; Verstraeten, Willem W.; Sanders, Abram F. J.

2014-05-01

Mapping terrestrial chlorophyll fluorescence is a crucial activity to obtain information on the functional status of vegetation and to improve estimates of light-use efficiency (LUE) and global primary productivity (GPP). GPP quantifies carbon fixation by plant ecosystems and is therefore an important parameter for budgeting terrestrial carbon cycles. Satellite remote sensing offers an excellent tool for investigating GPP in a spatially explicit fashion across different scales of observation. The GPP estimates, however, still remain largely uncertain due to biotic and abiotic factors that influence plant production. Sun-induced fluorescence has the ability to enhance our knowledge on how environmentally induced changes affect the LUE. This can be linked to optical derived remote sensing parameters thereby reducing the uncertainty in GPP estimates. Satellite measurements provide a relatively new perspective on global sun-induced fluorescence, enabling us to quantify spatial distributions and changes over time. Techniques have recently been developed to retrieve fluorescence emissions from hyperspectral satellite measurements. We use data from the Global Ozone Monitoring Instrument 2 (GOME2) to infer terrestrial fluorescence. The spectral signatures of three basic components atmospheric: absorption, surface reflectance, and fluorescence radiance are separated using reference measurements of non-fluorescent surfaces (desserts, deep oceans and ice) to solve for the atmospheric absorption. An empirically based principal component analysis (PCA) approach is applied similar to that of Joiner et al. (2013, ACP). Here we show our first global maps of the GOME2 retrievals of chlorophyll fluorescence. First results indicate fluorescence distributions that are similar with that obtained by GOSAT and GOME2 as reported by Joiner et al. (2013, ACP), although we find slightly higher values. In view of optimizing the fluorescence retrieval, we will show the effect of the references

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.

EFFECT OF CLIMATE CHANGE ON COCOA PRODUCTIVITY IN ...

African Journals Online (AJOL)

Prof. Adipala Ekwamu

The study examined the relative effect of climate change on the productivity of cocoa in Nigeria. Data employed were national ... balance and harm agricultural sectors. However, .... and animal life which will inexorably affect productivity of ...

The effect of improving primary care depression management on employee absenteeism and productivity. A randomized trial.

Science.gov (United States)

Rost, Kathryn; Smith, Jeffrey L; Dickinson, Miriam

2004-12-01

To test whether an intervention to improve primary care depression management significantly improves productivity at work and absenteeism over 2 years. Twelve community primary care practices recruiting depressed primary care patients identified in a previsit screening. Practices were stratified by depression treatment patterns before randomization to enhanced or usual care. After delivering brief training, enhanced care clinicians provided improved depression management over 24 months. The research team evaluated productivity and absenteeism at baseline, 6, 12, 18, and 24 months in 326 patients who reported full-or part-time work at one or more completed waves. Employed patients in the enhanced care condition reported 6.1% greater productivity and 22.8% less absenteeism over 2 years. Consistent with its impact on depression severity and emotional role functioning, intervention effects were more observable in consistently employed subjects where the intervention improved productivity by 8.2% over 2 years at an estimated annual value of US 1982 dollars per depressed full-time equivalent and reduced absenteeism by 28.4% or 12.3 days over 2 years at an estimated annual value of US 619 dollars per depressed full-time equivalent. This trial, which is the first to our knowledge to demonstrate that improving the quality of care for any chronic disease has positive consequences for productivity and absenteeism, encourages formal cost-benefit research to assess the potential return-on-investment employers of stable workforces can realize from using their purchasing power to encourage better depression treatment for their employees.

Production of freely-migrating defects during irradiation

International Nuclear Information System (INIS)

Rehn, L.E.; Okamoto, P.R.

1986-09-01

During irradiation at elevated temperatures, vacancy and interstitial defects that escape can produce several different types of microstructural changes. Hence the production rate of freely-migrating defects must be known as a function of irradiating particle species and energy before quantitative correlations can be made between microstructural changes. Our fundamental knowledge of freely-migrating defect production has increased substantially in recent years. Critical experimental findings that led to the improved understanding are reviewed in this paper. A strong similarity is found for the dependence of freely-migrating defect production on primary recoil energy as measured in a variety of metals and alloys by different authors. The efficiency for producing freely-migrating defects decreases much more strongly with increasing primary recoil energy than does the efficiency for creating stable defects at liquid helium temperatures. The stronger decrease can be understood in terms of additional intracascade recombination that results from the nonrandom distribution of defects existing in the primary damage state for high primary recoil energies. Although the existing data base is limited to fcc materials, the strong similarity in the reported investigations suggests that the same dependence of freely-migrating defect production on primary recoil energy may be characteristic of a wide variety of other alloy systems as well. 52 refs., 4 figs

Performance analysis of spectrum sensing with multiple status changes in primary user traffic

KAUST Repository

Tang, Liang; Chen, Yunfei; Hines, Evor L.; Alouini, Mohamed-Slim

2012-01-01

In this letter, the impact of primary user traffic with multiple status changes on the spectrum sensing performance is analyzed. Closed-form expressions for the probabilities of false alarm and detection are derived. Numerical results show

[Characteristics of terrestrial ecosystem primary productivity in East Asia based on remote sensing and process-based model].

Science.gov (United States)

Zhang, Fang-Min; Ju, Wei-Min; Chen, Jing-Ming; Wang, Shao-Qiang; Yu, Gui-Rui; Han, Shi-Jie

2012-02-01

Based on the bi-linearly interpolated meteorological reanalysis data from National Centers for Environmental Prediction, USA and by using the leaf area index data derived from the GIMMS NDVI to run the process-based Boreal Ecosystems Productivity Simulator (BEPS) model, this paper simulated and analyzed the spatiotemporal characteristics of the terrestrial ecosystem gross primary productivity (GPP) and net primary productivity (NPP) in East Asia in 2000-2005. Before regional simulating and calculating, the observation GPP data of different terrestrial ecosystem in 15 experimental stations of AsiaFlux network and the inventory measurements of NPP at 1300 sampling sites were applied to validate the BEPS GPP and NPP. The results showed that BEPS could well simulate the changes in GPP and NPP of different terrestrial ecosystems, with the R2 ranging from 0.86 to 0.99 and the root mean square error (RMSE) from 0.2 to 1.2 g C x m(-2) x d(-1). The simulated values by BEPS could explain 78% of the changes in annual NPP, and the RMSE was 118 g C x m(-2) x a(-1). In 2000-2005, the averaged total GPP and total NPP of the terrestrial ecosystems in East Asia were 21.7 and 10.5 Pg C x a(-1), respectively, and the GPP and NPP exhibited similar spatial and temporal variation patterns. During the six years, the total NPP of the terrestrial ecosystems varied from 10.2 to 10.7 Pg C x a(-1), with a coefficient of variation being 2. 2%. High NPP (above 1000 g C x m(-2) x a(-1)) occurred in the southeast island countries, while low NPP (below 30 g C x m(-2) x a(-1)) occurred in the desert area of Northwest China. The spatial patterns of NPP were mainly attributed to the differences in the climatic variables across East Asia. The NPP per capita also varied greatly among different countries, which was the highest (70217 kg C x a(-1)) in Mongolia, far higher than that (1921 kg C x a(-1)) in China, and the lowest (757 kg C x a(-1)) in India.

Climate Change Impacts for the Conterminous USA. An Integrated Assessment. Part 6. Distribution and Productivity of Unmanaged Ecosystems

Energy Technology Data Exchange (ETDEWEB)

Izaurralde, R.C.; Thomson, A.M.; Rosenberg, N.J. [The Joint Global Change Research Institute, 8400 Baltimore Avenue, Suite 201, College Park, Maryland, 20740-2496 (United States); Brown, R.A. [Independent Project Analysis, 11150 Sunset Hills Rd., Suite 3, Reston, Virginia, 20190 (United States)

2005-03-01

Human activities have altered the distribution and quality of terrestrial ecosystems. Future demands for goods and services from terrestrial ecosystems will occur in a world experiencing human-induced climate change. In this study, we characterize the range in response of unmanaged ecosystems in the conterminous U.S. to 12 climate change scenarios. We obtained this response by simulating the climatically induced shifts in net primary productivity and geographical distribution of major biomes in the conterminous U.S. with the BIOME 3 model. BIOME 3 captured well the potential distribution of major biomes across the U.S. under baseline (current) climate. BIOME 3 also reproduced the general trends of observed net primary production (NPP) acceptably. The NPP projections were reasonable for forests, but not for grasslands where the simulated values were always greater than those observed. Changes in NPP would be most severe under the BMRC climate change scenario in which severe changes in regional temperatures are projected. Under the UIUC and UIUC + Sulfate scenarios, NPP generally increases, especially in the West where increases in precipitation are projected to be greatest. A CO2-fertilization effect either amplified increases or alleviated losses in modeled NPP. Changes in NPP were also associated with changes in the geographic distribution of major biomes. Temperate/boreal mixed forests would cover less land in the U.S. under most of the climate change scenarios examined. Conversely, the temperate conifer and temperate deciduous forests would increase in areal extent under the UIUC and UIUC + Sulfate scenarios. The Arid Shrubland/Steppe would spread significantly across the southwest U.S. under the BMRC scenario. A map overlay of the simulated regions that would lose or gain capacity to produce corn and wheat on top of the projected distribution of natural ecosystems under the BMRC and UIUC scenarios (Global mean temperature increase of +2.5C, no CO2 effect

Structural Uncertainty in Model-Simulated Trends of Global Gross Primary Production

Directory of Open Access Journals (Sweden)

Zaichun Zhu

2013-03-01

Full Text Available Projected changes in the frequency and severity of droughts as a result of increase in greenhouse gases have a significant impact on the role of vegetation in regulating the global carbon cycle. Drought effect on vegetation Gross Primary Production (GPP is usually modeled as a function of Vapor Pressure Deficit (VPD and/or soil moisture. Climate projections suggest a strong likelihood of increasing trend in VPD, while regional changes in precipitation are less certain. This difference in projections between VPD and precipitation can cause considerable discrepancies in the predictions of vegetation behavior depending on how ecosystem models represent the drought effect. In this study, we scrutinized the model responses to drought using the 30-year record of Global Inventory Modeling and Mapping Studies (GIMMS 3g Normalized Difference Vegetation Index (NDVI dataset. A diagnostic ecosystem model, Terrestrial Observation and Prediction System (TOPS, was used to estimate global GPP from 1982 to 2009 under nine different experimental simulations. The control run of global GPP increased until 2000, but stayed constant after 2000. Among the simulations with single climate constraint (temperature, VPD, rainfall and solar radiation, only the VPD-driven simulation showed a decrease in 2000s, while the other scenarios simulated an increase in GPP. The diverging responses in 2000s can be attributed to the difference in the representation of the impact of water stress on vegetation in models, i.e., using VPD and/or precipitation. Spatial map of trend in simulated GPP using GIMMS 3g data is consistent with the GPP driven by soil moisture than the GPP driven by VPD, confirming the need for a soil moisture constraint in modeling global GPP.

Examining the roles that changing harvested areas, closing yield-gaps, and increasing yield ceilings have had on crop production

Science.gov (United States)

Johnston, M.; Ray, D. K.; Mueller, N. D.; Foley, J. A.

2011-12-01

With an increasing and increasingly affluent population, there has been tremendous effort to examine strategies for sustainably increasing agricultural production to meet this surging global demand. Before developing new solutions from scratch, though, we believe it is important to consult our recent agricultural history to see where and how agricultural production changes have already taken place. By utilizing the newly created temporal M3 cropland datasets, we can for the first time examine gridded agricultural yields and area, both spatially and temporally. This research explores the historical drivers of agricultural production changes, from 1965-2005. The results will be presented spatially at the global-level (5-min resolution), as well as at the individual country-level. The primary research components of this study are presented below, including the general methodology utilized in each phase and preliminary results for soybean where available. The complete assessment will cover maize, wheat, rice, soybean, and sugarcane, and will include country-specific analysis for over 200 countries, states, territories and protectorates. Phase 1: The first component of our research isolates changes in agricultural production due to variation in planting decisions (harvested area) from changes in production due to intensification efforts (yield). We examine area/yield changes at the pixel-level over 5-year time-steps to determine how much each component has contributed to overall changes in production. Our results include both spatial patterns of changes in production, as well as spatial maps illustrating to what degree the production change is attributed to area and/or yield. Together, these maps illustrate where, why, and by how much agricultural production has changed over time. Phase 2: In the second phase of our research we attempt to determine the impact that area and yield changes have had on agricultural production at the country-level. We calculate a production

Recent productivity developments and technical change in Danish organic farming - stagnation?

DEFF Research Database (Denmark)

Sauer, Johannes; Graversen, Jesper Tranbjerg; Park, Tim

This paper attempts to quantitatively measure the change in the productivity of Dan-ish organic farming in recent years by using panel data on 56 organic farms mainly engaged in milk production for the period 2002 to 2004. Based on a translog pro-duction frontier framework the technical and scale...... efficiency on farm level is ana-lysed by considering also curvature consistency. The total change in productivity for the reference period is measured by using the Malmquist total factor productivity in-dex approach based on a time trends as well as a general index model specification. Input specific bias...... in technical change as well elasticities of input substitution are analyzed. Fators for the development of technical change and the change in effi-ciency over time are investigated by applying a bootstrapped ITSUR technique. Fi-nally we try to conclude on the significance of subsidies for promoting long term...

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...

The changes of bone mineralization after parathyroidectomy in primary hyperparathyroidism. Case report

International Nuclear Information System (INIS)

Przedlacki, J.; Nawrot, I.; Chudzinski, W.

1995-01-01

The aim of the study was to evaluate the changes of bone demineralization in the patient after parathyroidectomy in primary hyperparathyroidism. Bone mineralization was evaluated by Lunar DPX-L equipment in lumbar spine, femoral neck, radius and total skeleton area in 3 months intervals during 18 months period. Because of transient after surgical hypocalcemia she has received active metabolite of vitamin D - Alfacalcidolum during one year. After removal of parathyroid adenoma there was disappearance of clinical and biochemical signs of primary hyperparathyroidism. At the same time there was total normalization of bone mineral density in lumbar spine, femoral neck, ultradistal site of radius and total area. There was partial normalization of bone mineralization in radius shaft. The surgery of adenoma in primary hyperparathyroidism with transient treatment with active metabolite of vitamin D is successful therapy of bone demineralization in this disease. (author). 5 refs, 2 figs

Southern Ocean phytoplankton physiology in a changing climate.

Science.gov (United States)

Petrou, Katherina; Kranz, Sven A; Trimborn, Scarlett; Hassler, Christel S; Ameijeiras, Sonia Blanco; Sackett, Olivia; Ralph, Peter J; Davidson, Andrew T

2016-09-20

The Southern Ocean (SO) is a major sink for anthropogenic atmospheric carbon dioxide (CO 2 ), potentially harbouring even greater potential for additional sequestration of CO 2 through enhanced phytoplankton productivity. In the SO, primary productivity is primarily driven by bottom up processes (physical and chemical conditions) which are spatially and temporally heterogeneous. Due to a paucity of trace metals (such as iron) and high variability in light, much of the SO is characterised by an ecological paradox of high macronutrient concentrations yet uncharacteristically low chlorophyll concentrations. It is expected that with increased anthropogenic CO 2 emissions and the coincident warming, the major physical and chemical process that govern the SO will alter, influencing the biological capacity and functioning of the ecosystem. This review focuses on the SO primary producers and the bottom up processes that underpin their health and productivity. It looks at the major physico-chemical drivers of change in the SO, and based on current physiological knowledge, explores how these changes will likely manifest in phytoplankton, specifically, what are the physiological changes and floristic shifts that are likely to ensue and how this may translate into changes in the carbon sink capacity, net primary productivity and functionality of the SO. Copyright © 2016 Elsevier GmbH. All rights reserved.

Assessment of primary production in a eutrophic lake from carbon and nitrogen isotope ratios of a carnivorous fish

International Nuclear Information System (INIS)

Yoshioka, Takahito

1991-01-01

The carbon and nitrogen isotope ratios of Hypomesus transpacificus (a pond smelt) in a eutrophic lake, Lake Suwa, were measured from April to September in 1986 and 1987. The differences in the isotope ratios between these two years were observed. The stable isotopes were transferred from phytoplankton to zooplankton and pond smelt, associated with organic matters. Therefore, the difference in the isotope ratios in two years seemed to reflect the differences of the proceeding of primary production. It was suggested that the carbon and nitrogen isotope ratios of animal, whose trophic level is far from primary producer, can be the qualitative indicators for assessing the primary production in a lake ecosystem. (author)

The Effect of Improving Primary Care Depression Management on Employee Absenteeism and Productivity A Randomized Trial

Science.gov (United States)

Rost, Kathryn; Smith, Jeffrey L.; Dickinson, Miriam

2005-01-01

Objective: To test whether an intervention to improve primary care depression management significantly improves productivity at work and absenteeism over 2 years. Setting and Subjects: Twelve community primary care practices recruiting depressed primary care patients identified in a previsit screening. Research Design: Practices were stratified by depression treatment patterns before randomization to enhanced or usual care. After delivering brief training, enhanced care clinicians provided improved depression management over 24 months. The research team evaluated productivity and absenteeism at baseline, 6, 12, 18, and 24 months in 326 patients who reported full-or part-time work at one or more completed waves. Results: Employed patients in the enhanced care condition reported 6.1% greater productivity and 22.8% less absenteeism over 2 years. Consistent with its impact on depression severity and emotional role functioning, intervention effects were more observable in consistently employed subjects where the intervention improved productivity by 8.2% over 2 years at an estimated annual value of $1982 per depressed full-time equivalent and reduced absenteeism by 28.4% or 12.3 days over 2 years at an estimated annual value of $619 per depressed full-time equivalent. Conclusions: This trial, which is the first to our knowledge to demonstrate that improving the quality of care for any chronic disease has positive consequences for productivity and absenteeism, encourages formal cost-benefit research to assess the potential return-on-investment employers of stable workforces can realize from using their purchasing power to encourage better depression treatment for their employees. PMID:15550800

Modelling and numerical simulation of the corrosion product transport in the pressurised water reactor primary circuit

International Nuclear Information System (INIS)

Marchetto, C.

2002-05-01

During operation of pressurised water reactor, corrosion of the primary circuit alloys leads to the release of metallic species such as iron, nickel and cobalt in the primary fluid. These corrosion products are implicated in different transport phenomena and are activated in the reactor core where they are submitted to neutron flux. The radioactive corrosion products are afterwards present in the out of flux parts of primary circuit where they generate a radiation field. The first part of this study deals with the modelling of the corrosion: product transport phenomena. In particular, considering the current state of the art, corrosion and release mechanisms are described empirically, which allows to take into account the material surface properties. New mass balance equations describing the corrosion product behaviour are thus obtained. The numerical resolution of these equations is implemented in the second part of this work. In order to obtain large time steps, we choose an implicit time scheme. The associated system is linearized from the Newton method and is solved by a preconditioned GMRES method. Moreover, a time step auto-adaptive management based on Newton iterations is performed. Consequently, an efficient resolution has been implemented, allowing to describe not only the quasi-steady evolutions but also the fast transients. In a last step, numerical simulations are carried out in order to validate the new corrosion product transport modelling and to illustrate the capabilities of this modelling. Notably, the numerical results obtained indicate that the code allows to restore the on-site observations underlining the influence of material surface properties on reactor contamination. (author)

Climate Change Education: Student Media Production to Educate and Engage

Science.gov (United States)

Rooney-Varga, J. N.; Brisk, A. A.; Ledley, T. S.; Shuldman, M.

2011-12-01

Climate change education offers many challenges, including the complexity of the natural and human systems involved, a need for a multi-disciplinary perspective, and the psychological barriers to learning that result from a problem that frequently elicits a sense of being overwhelmed and powerless. The implications of climate change impacts and/or solutions can be especially overwhelming for today's students, who are likely to be confronted with many projected changes within their lifetimes. We are developing approaches to incorporate video production by students at both the high school and university levels in order to overcome many of the challenges unique to climate change education. Through media production, students are asked to convey complex topics using clear, simple language and metaphor, so their content knowledge must be deep enough to educate others. Video production is a team effort (director, camera person, editor, etc.) and inherently creates an opportunity for learning in a social context, which has been shown to lead to better learning outcomes in climate change education. Video production also promotes the basic tenets of engagement theory, in which a small group of students is in constant contact with the content and, ideally, creates a product that can be disseminated broadly. Lastly, putting students behind the camera can give them a voice and a sense of empowerment, fostering active participation in the learning process. While video is a medium that is readily disseminated to a broad audience, our focus is on the process (i.e., learning outcomes of students directly involved in media production), not the product. However, we have found that providing students with a means to add their voices to the broader public's discussion of climate change has a positive impact on student engagement with climate change science and on public awareness this problem beyond the classroom. While student-produced media pieces are not intended to provide in

Modeling gross primary production of an evergreen needleleaf forest using MODIS and climate data

Science.gov (United States)

Xiangming Xiao; Qingyuan Zhang; David Hollinger; John Aber; Berrien, III Moore

2005-01-01

Forest canopies are composed of photosynthetically active vegetation (PAV, chloroplasts) and nonphotosynthetic vegetation (NPV, e.g., cell wall, vein, branch). The fraction of photosynthetically active radiation (PAR) absorbed by the canopy (FAPAR) should be partitioned into FAPARPAV and FAPARNPV. Gross primary production (...

78 FR 69755 - International Product and Price Changes

Science.gov (United States)

2013-11-21

... POSTAL SERVICE 39 CFR Part 20 International Product and Price Changes AGENCY: Postal Service TM... Service, International Mail Manual (IMM[supreg]), to reflect the prices, product features, and...-0372. SUPPLEMENTARY INFORMATION: New prices are available under Docket Number CP2014-5 on the Postal...

76 FR 75786 - International Product and Price Changes

Science.gov (United States)

2011-12-05

... POSTAL SERVICE 39 CFR Part 20 International Product and Price Changes AGENCY: Postal Service TM... Service, International Mail Manual (IMM[supreg]), to reflect the prices, product features, and.... SUPPLEMENTARY INFORMATION: New prices are available under Docket Number CP2012-2 on the Postal Regulatory...

Primary productivity of marine macrophytes in the coral reef lagoon of the Kadmat Island, Lakshadweep

Digital Repository Service at National Institute of Oceanography (India)

Dhargalkar, V.K.; Shaikh, N.

n situ primary productivity measurements were carried out with different macrophyte species (belonging to four groups) dominating the benthic communities in the coral reef lagoon of the Kadmat Island of the Lakshadweep Archipelago...

Seasonal variability of mixed layer in the central Arabian Sea and its implication on nutrients and primary productivity

Digital Repository Service at National Institute of Oceanography (India)

PrasannaKumar, S.; Narvekar, J.

-1 Seasonal variability of mixed layer in the central Arabian Sea and its implication on nutrients and primary productivity S. Prasanna Kumar and Jayu Narvekar National Institute of Oceanography, Dona Paula, Goa-403 004, India... on a 2? x 4? grids up to a depth of 500m. Monthly mean temperature and salinity data were used to calculate the sigma-t values (UNESCO, 1981). We also used nitrate, chlorophyll a and primary productivity data in the upper 120m water column...

Behavior Change without Behavior Change Communication: Nudging Handwashing among Primary School Students in Bangladesh

Science.gov (United States)

Dreibelbis, Robert; Kroeger, Anne; Hossain, Kamal; Venkatesh, Mohini; Ram, Pavani K.

2016-01-01

Behavior change communication for improving handwashing with soap can be labor and resource intensive, yet quality results are difficult to achieve. Nudges are environmental cues engaging unconscious decision-making processes to prompt behavior change. In this proof-of-concept study, we developed an inexpensive set of nudges to encourage handwashing with soap after toilet use in two primary schools in rural Bangladesh. We completed direct observation of behaviors at baseline, after providing traditional handwashing infrastructure, and at multiple time periods following targeted handwashing nudges (1 day, 2 weeks, and 6 weeks). No additional handwashing education or motivational messages were completed. Handwashing with soap among school children was low at baseline (4%), increasing to 68% the day after nudges were completed and 74% at both 2 weeks and 6 weeks post intervention. Results indicate that nudge-based interventions have the potential to improve handwashing with soap among school-aged children in Bangladesh and specific areas of further inquiry are discussed. PMID:26784210

Behavior Change without Behavior Change Communication: Nudging Handwashing among Primary School Students in Bangladesh

Directory of Open Access Journals (Sweden)

Robert Dreibelbis

2016-01-01

Full Text Available Behavior change communication for improving handwashing with soap can be labor and resource intensive, yet quality results are difficult to achieve. Nudges are environmental cues engaging unconscious decision-making processes to prompt behavior change. In this proof-of-concept study, we developed an inexpensive set of nudges to encourage handwashing with soap after toilet use in two primary schools in rural Bangladesh. We completed direct observation of behaviors at baseline, after providing traditional handwashing infrastructure, and at multiple time periods following targeted handwashing nudges (1 day, 2 weeks, and 6 weeks. No additional handwashing education or motivational messages were completed. Handwashing with soap among school children was low at baseline (4%, increasing to 68% the day after nudges were completed and 74% at both 2 weeks and 6 weeks post intervention. Results indicate that nudge-based interventions have the potential to improve handwashing with soap among school-aged children in Bangladesh and specific areas of further inquiry are discussed.

Behavior Change without Behavior Change Communication: Nudging Handwashing among Primary School Students in Bangladesh.

Science.gov (United States)

Dreibelbis, Robert; Kroeger, Anne; Hossain, Kamal; Venkatesh, Mohini; Ram, Pavani K

2016-01-14

Behavior change communication for improving handwashing with soap can be labor and resource intensive, yet quality results are difficult to achieve. Nudges are environmental cues engaging unconscious decision-making processes to prompt behavior change. In this proof-of-concept study, we developed an inexpensive set of nudges to encourage handwashing with soap after toilet use in two primary schools in rural Bangladesh. We completed direct observation of behaviors at baseline, after providing traditional handwashing infrastructure, and at multiple time periods following targeted handwashing nudges (1 day, 2 weeks, and 6 weeks). No additional handwashing education or motivational messages were completed. Handwashing with soap among school children was low at baseline (4%), increasing to 68% the day after nudges were completed and 74% at both 2 weeks and 6 weeks post intervention. Results indicate that nudge-based interventions have the potential to improve handwashing with soap among school-aged children in Bangladesh and specific areas of further inquiry are discussed.

Climate Change, Risk and Grain Production in China

OpenAIRE

Holst, Rainer; Yu, Xiaohua; Grun, Carola

2010-01-01

This paper employs the production function-based method proposed by Just and Pope (1978, 1979) to explicitly analyze production risk in the context of Chinese grain farming and climate change, and test for potential endogeneity of climate factors in Chinese grain production. Our results indicate that grain production in south China might, at least in the short run, could be a net beneficiary of global warming. In particular, we find that a 1 °C increase in annual average temperature in South ...

EFFECTS OF CLIMATE CHANGE ON POULTRY PRODUCTION IN ONDO STATE, NIGERIA

Directory of Open Access Journals (Sweden)

G.B. Adesiji

2013-02-01

Full Text Available The study assesses the effects of climate change on poultry production in Ondo State, Nigeria. Eighty three (83 poultry farmers were interviewed to elicit relevant information in line with the objectives of the study. Descriptive statistics and inferential statistical tools were used for data analysis. Findings revealed that majority (93.3% of the respondents are aware of climate change, 78%, 98.8% and 86.7% of the respondents agreed that temperature fluctuation, increased in sunshine intensity and global warming has a negative effects on poultry production, 72.4% of the respondents agreed that prices of feed grains are usually high in hot and dry seasons which may affect cost of production and number of birds to raise for egg and meat production in the farm, 73.5% of the respondents agreed that climate change has effect on feed grain availability, this implies that high temperature and low rainfall are climatic factors that affect general grain harvest, their supply to the market and ultimately cost of poultry production. the findings further revealed that 94% of the respondents agreed that climate change affects egg and meat production pattern and 95.2% of the respondents agreed that moist climatic conditions encouraged the distribution and development of diseases. Infrential statistics shows that there is a significant relationship between respondents' socio-economic characteristics and perception of poultry farmers on effects of climate change on poultry production since p > 0.05 (r = 0.454, p= 0.001, the findings also shows that there is a significant relationship between socio-economic characteristics of respondents and their level of awareness of climate change since the p > 0.05 (r = 0.652, p = 0.001. it is recomended extension agents and other development agencies need to educate the poultry farmers more about the effects posed by climate change on poultry production and intensify awareness campaign to poultry farmers on how to reduce

Primary production, nutrients, and size spectra of suspended particles in the southern North Sea

NARCIS (Netherlands)

Gieskes, W.W.C.

1972-01-01

The effect of nutrient enrichment from the Rhine on some major characteristics of the phytoplankton ecosystem of Dutch coastal waters was studied with ¹⁴C, liquid scintillation and Coulter Counter techniques. The magnitude of primary production in the most eutrophic waters closest to

Grassland production under global change scenarios for New Zealand pastoral agriculture